阅读说明：本技术 作业机 (Working machine ) 是由 头师正英 长滨和 福冈俊彦 白井真人 于 2020-04-03 设计创作，主要内容包括：一种作业机,具备：促动器,使伸缩式的臂伸缩；电气驱动源,设置于促动器,基于来自电源的供电进行驱动；动作部,基于电气驱动源的动力而动作；电路,能够对驱动状态和制动状态进行切换,在该驱动状态下,许可从电源向电气驱动源的供电,驱动电气驱动源,在该制动状态下,停止从电源向电气驱动源的供电并生成赋予电气驱动源的制动力；以及控制部,控制驱动状态和制动状态间的切换。(A work machine is provided with: an actuator configured to extend and retract the telescopic arm; an electric drive source provided in the actuator and driven by power supplied from a power supply; an operation unit that operates based on power of the electric drive source; a circuit capable of switching between a driving state in which power supply from the power supply to the electric drive source is permitted to drive the electric drive source and a braking state in which power supply from the power supply to the electric drive source is stopped and braking force applied to the electric drive source is generated; and a control unit for controlling switching between the drive state and the brake state.)

1. A working machine is characterized by comprising:

an actuator configured to extend and retract the telescopic arm;

an electric drive source provided in the actuator and driven by power supplied from a power source;

an operation unit that operates based on power of the electric drive source;

a circuit capable of switching between a driving state in which power supply from the power supply to the electric drive source is permitted and the electric drive source is driven, and a braking state in which power supply from the power supply to the electric drive source is stopped and braking force applied to the electric drive source is generated; and

and a control unit that controls switching between the drive state and the brake state.

2. The work machine of claim 1,

the arm has a first arm element and a second arm element which are overlapped in a telescopic way,

the operation unit includes:

a first coupling mechanism that operates based on power of the electric drive source and switches between a coupled state and an uncoupled state between the first arm element and the actuator; and

and a second coupling mechanism that operates based on power of the electric drive source and switches between a coupled state and an uncoupled state between the first arm element and the second arm element.

3. The work machine of claim 2,

the first connecting mechanism is provided with a first force applying mechanism,

the first link mechanism switches the first arm element and the actuator from a linked state to a non-linked state based on power of the electric drive source,

the first link mechanism switches the first arm element and the actuator from a non-linked state to a linked state based on the biasing force of the first biasing mechanism.

4. The work machine according to claim 2 or 3,

the second connecting mechanism is provided with a second force applying mechanism,

the second coupling mechanism switches the first arm element and the second arm element from a coupled state to a non-coupled state based on power of the electric drive source,

the second coupling mechanism switches the first arm element and the second arm element from a non-coupled state to a coupled state based on the biasing force of the second biasing mechanism.

5. The work machine of claim 3,

the control unit sets the electric circuit to the braking state when the first link mechanism switches the first arm element and the actuator from the non-linked state to the linked state based on the biasing force of the first biasing mechanism.

6. The work machine of claim 4,

the control unit sets the circuit to the braking state when the second coupling mechanism switches the first arm element and the second arm element from the non-coupled state to the coupled state based on the biasing force of the second biasing mechanism.

7. The working machine according to any one of claims 2 to 6,

the driving state includes: a first driving state in which the electric drive source is rotated in a first direction, a second driving state in which the electric drive source is rotated in a second direction,

in the first driving state, the first link mechanism operates based on an output of the electric drive source,

in the second driving state, the second coupling mechanism operates based on an output of the electric drive source.

8. The working machine according to any one of claims 1 to 7,

the electric circuit has a closed circuit including the electric drive source in the braking state,

the braking force is generated by consuming electric power generated based on rotation of the electric drive source in the closed circuit.

Technical Field

The present invention relates to a work machine including a telescopic arm.

Background

Patent document 1 discloses a mobile crane including: a telescopic arm in which a plurality of arm elements are overlapped in a nested state (also referred to as a "telescopic state"); and a hydraulic telescopic cylinder which extends the telescopic arm.

The telescopic arm has an arm connecting pin for connecting adjacent and overlapping arm elements. The arm element (hereinafter referred to as a "movable arm element") whose connection by the arm connecting pin is released is movable in the longitudinal direction (also referred to as an "expansion/contraction direction") with respect to the other arm elements.

The telescopic cylinder has a rod member and a cylinder member. Such a telescopic cylinder connects the cylinder member to the movable arm element via a cylinder connecting pin. In this state, if the cylinder member moves in the telescopic direction, the movable arm element moves together with the cylinder member to extend and contract the telescopic arm.

Prior art documents

Patent document

Patent document 1, Japanese patent laid-open No. 2012-96928

Disclosure of Invention

Problems to be solved by the invention

The crane described above includes a hydraulic actuator for moving the arm connecting pin, a hydraulic actuator for moving the cylinder connecting pin, and a hydraulic circuit for supplying pressure oil to each of these actuators. Such a hydraulic circuit is for example arranged around the telescopic arm. Therefore, the degree of freedom in design around the telescopic arm may be reduced.

The invention aims to provide a working machine capable of improving the degree of freedom of design around a telescopic arm.

Means for solving the problems

The present invention relates to a working machine, including:

an actuator configured to extend and retract the telescopic arm;

an electric drive source provided in the actuator and driven by power supplied from a power supply;

an operation unit that operates based on power of the electric drive source;

a circuit capable of switching between a driving state in which power supply from the power supply to the electric drive source is permitted to drive the electric drive source and a braking state in which power supply from the power supply to the electric drive source is stopped and braking force applied to the electric drive source is generated; and

and a control unit for controlling switching between the drive state and the brake state.

Effects of the invention

According to the present invention, the degree of freedom in designing the periphery of the telescopic arm can be improved.

Drawings

Fig. 1 is a schematic view of a mobile crane according to an embodiment.

Fig. 2A to 2E are schematic views for explaining the structure and the telescopic operation of the telescopic arm.

Fig. 3A is an oblique view of the actuator.

Fig. 3B is an enlarged view of a portion a of fig. 3A.

Fig. 4 is a partial plan view of the actuator.

Fig. 5 is a partial side view of the actuator.

FIG. 6 is A of FIG. 5₁And (6) looking into the view.

Fig. 7 is a perspective view of the pin moving module in a state where the arm connecting pin is held.

Fig. 8 is a front view of the pin moving module in an expanded state and in a state where the arm connecting pin is held.

FIG. 9 is A of FIG. 8₂And (6) looking into the view.

FIG. 10 is A of FIG. 8₃And (6) looking into the view.

FIG. 11 is A of FIG. 8₄And (6) looking into the view.

Fig. 12 is a front view of the pin moving module in which the arm connecting mechanism is in a contracted state and the cylinder connecting mechanism is in an expanded state.

Fig. 13 is a front view of the pin moving module in which the arm connecting mechanism is in an expanded state and the cylinder connecting mechanism is in a contracted state.

Fig. 14A is a schematic diagram for explaining the operation of the lock mechanism.

Fig. 14B is a schematic diagram for explaining the operation of the lock mechanism.

Fig. 14C is a schematic diagram for explaining the operation of the lock mechanism.

Fig. 14D is a schematic diagram for explaining the operation of the lock mechanism.

Fig. 15A is a schematic diagram for explaining the action of the lock mechanism.

Fig. 15B is a schematic diagram for explaining the action of the lock mechanism.

Fig. 16A is a circuit diagram of a circuit in a non-energized state.

Fig. 16B is a circuit diagram of a circuit in the first driving state.

Fig. 16C is a circuit diagram of a circuit in the second driving state.

Fig. 16D is a circuit diagram of a circuit in the braking state.

Fig. 17 is a timing chart at the time of the extending operation of the telescopic arm.

Fig. 18A is a schematic diagram for explaining the operation of the cylinder connecting mechanism.

Fig. 18B is a schematic diagram for explaining the operation of the cylinder connecting mechanism.

Fig. 18C is a schematic diagram for explaining the operation of the cylinder connecting mechanism.

Fig. 19A is a schematic diagram for explaining the operation of the arm connecting mechanism.

Fig. 19B is a schematic diagram for explaining the operation of the arm connecting mechanism.

Fig. 19C is a schematic diagram for explaining the operation of the arm connecting mechanism.

Detailed Description

Hereinafter, an example of an embodiment according to the present invention will be described in detail with reference to the drawings. The crane according to the embodiment described later is an example of the working machine according to the present invention, and the present invention is not limited to the embodiment described later.

[ embodiment ]

Fig. 1 is a schematic view of a mobile crane 1 (in the illustrated case, a crane with a complex terrain) according to the present embodiment. The mobile crane 1 corresponds to an example of a working machine.

Examples of the mobile crane include an all terrain crane, a truck crane, and a loading truck crane (also referred to as a "cargo crane"). However, the work machine according to the present invention is not limited to the mobile crane, and may be applied to other work vehicles (e.g., a crane and an aerial work vehicle) provided with a telescopic arm.

First, the mobile crane 1 and the telescopic arm 14 included in the mobile crane 1 will be described in brief below. Next, a specific structure and operation of the actuator 2, which are characteristics of the mobile crane 1 according to the present embodiment, will be described.

< Mobile Crane >

As shown in fig. 1, the mobile crane 1 includes a traveling body 10, outriggers 11, a revolving platform 12, a telescopic arm 14, an actuator 2 (not shown in fig. 1), an electric circuit 6 (see fig. 16A to 16D), a heave cylinder 15, a wire rope 16, and a hook 17.

The traveling body 10 has a plurality of wheels 101. The outriggers 11 are provided at four corners of the traveling body 10. The turn table 12 is provided on the upper portion of the traveling body 10 so as to be rotatable. The proximal end portion of the telescopic arm 14 is fixed to the turn table 12. The actuator 2 extends and contracts the telescopic arm 14. The heave cylinder 15 makes the telescopic arm 14 heave. A wire rope 16 depends from the front end of the telescopic arm 14. The hook 17 is provided at the front end of the wire rope 16.

< Telescopic arm >

Next, the telescopic arm 14 will be described with reference to fig. 1 and 2A to 2E. Fig. 2A to 2E are schematic diagrams for explaining the structure and the telescopic operation of the telescopic arm 14.

In fig. 1, the telescopic arm 14 is shown in an extended state. In fig. 2A, the telescopic arm 14 is shown in a contracted state. Fig. 2E shows the telescopic arm 14 in which only the front arm element 141 described later is extended.

The telescoping arm 14 includes a plurality of arm elements. The plurality of arm elements are each cylindrical. The plurality of arm elements are combined with each other in a telescopic manner. Specifically, in the contracted state, the plurality of arm elements are the tip arm element 141, the intermediate arm element 142, and the base arm element 143 in this order from the inside.

In the present embodiment, the front arm element 141 and the intermediate arm element 142 correspond to an example of a first arm element that is movable in the expansion and contraction direction. When the front arm element 141 moves in the extending and contracting direction with respect to the intermediate arm element 142, the front arm element 141 corresponds to an example of a first arm element, and the intermediate arm element 142 corresponds to an example of a second arm element. When the intermediate arm element 142 moves in the extending and contracting direction with respect to the base arm element 143, the intermediate arm element 142 corresponds to an example of a first arm element, and the base arm element 143 corresponds to an example of a second arm element. The movement of the base end arm element 143 in the expansion and contraction direction is restricted.

The telescopic arm 14 is sequentially extended from the arm element (i.e., the distal end arm element 141) disposed inside, and the state is shifted from the contracted state shown in fig. 2A to the extended state shown in fig. 1.

In the extended state, the intermediate arm element 142 is disposed between the base end arm element 143 closest to the base end side and the tip end arm element 141 closest to the tip end side. Further, the number of the intermediate arm elements may be plural.

The structure of the telescopic arm 14 is substantially the same as that of a conventionally known telescopic arm, but for convenience of description regarding the structure and operation of the actuator 2 to be described later, the structures of the front arm element 141 and the intermediate arm element 142 will be described below.

< front end arm element >

The distal end arm element 141 is cylindrical as shown in fig. 2A to 2E. The distal end arm element 141 has an internal space capable of accommodating the actuator 2. The base end of the distal arm element 141 includes a pair of cylinder pin receiving portions 141a and a pair of arm pin receiving portions 141 b.

The pair of cylinder pin receiving portions 141a are provided coaxially with each other at the base end portion of the distal arm element 141. The pair of cylinder pin receiving portions 141a are respectively engageable with and disengageable from a pair of cylinder coupling pins 454a and 454b (also referred to as "first coupling members") provided on the cylinder member 32 of the telescopic cylinder 3. That is, the pair of cylinder pin receivers 141a can be brought into any one of an engaged state in which they are engaged with the pair of cylinder coupling pins 454a and 454b and a disengaged state in which they are disengaged from the pair of cylinder coupling pins 454a and 454 b.

The cylinder connecting pins 454a and 454b move in the axial direction thereof based on the operation of a cylinder connecting mechanism 45 provided in the actuator 2 described later. The front end arm element 141 is movable in the extending and contracting direction together with the cylinder member 32 in a state where the pair of cylinder connecting pins 454a and 454b are engaged with the pair of cylinder pin receiving portions 141 a.

The pair of arm pin receiving portions 141b are provided coaxially with each other on the base end side of the cylinder pin receiving portion 141 a. The arm pin receiving portions 141b are respectively engageable with and disengageable from the pair of arm coupling pins 144a (also referred to as "second coupling members"). That is, the pair of arm pin receiving portions 141b can be brought into one of an engaged state in which they are engaged with the pair of arm connecting pins 144a and a disengaged state in which they are disengaged from the pair of arm connecting pins 144 a.

The pair of arm connecting pins 144a connect the front end arm element 141 and the intermediate arm element 142, respectively. The pair of arm connecting pins 144a move in the axial direction thereof based on the operation of the arm connecting mechanism 46 provided in the actuator 2. The pair of arm coupling pins 144a may also be understood as structural components of the arm coupling mechanism 46.

In a state where the distal end arm element 141 and the intermediate arm element 142 are coupled by the pair of arm coupling pins 144a, the arm coupling pin 144a is inserted so as to bridge between the arm pin receiving portion 141b of the distal end arm element 141 and the first arm pin receiving portion 142b or the second arm pin receiving portion 142c of the intermediate arm element 142, which will be described later.

In a state where the distal end arm element 141 and the intermediate arm element 142 are coupled (also referred to as a "coupled state"), the distal end arm element 141 is prohibited from moving in the extending and contracting direction with respect to the intermediate arm element 142.

On the other hand, in a state where the connection between the front arm element 141 and the intermediate arm element 142 is released (also referred to as a "non-connected state"), the front arm element 141 is movable in the extending and contracting direction with respect to the intermediate arm element 142.

< middle arm element >

The intermediate arm element 142 is cylindrical as shown in fig. 2A to 2E. The intermediate arm element 142 has an internal space capable of accommodating the front end arm element 141. The intermediate arm element 142 has a base end portion including a pair of cylinder pin receiving portions 142a, a pair of first arm pin receiving portions 142b, a pair of second arm pin receiving portions 142c, and a pair of third arm pin receiving portions 142 d.

The pair of cylinder pin receiving portions 142a and the pair of first arm pin receiving portions 142b are substantially the same as the pair of cylinder pin receiving portions 141a and the pair of arm pin receiving portions 141b of the distal end arm element 141, respectively.

The pair of third arm pin receiving portions 142d are provided coaxially with each other on the base end side of the pair of first arm pin receiving portions 142 b. A pair of arm connecting pins 144b are inserted into the pair of third arm pin receiving portions 142d, respectively. The pair of arm connecting pins 144b connect the intermediate arm element 142 and the base end arm element 143.

The pair of second arm pin receiving portions 142c are provided coaxially with each other at the distal end portion of the intermediate arm element 142. A pair of arm coupling pins 144a are inserted into the pair of second arm pin receiving portions 142c, respectively.

< actuator >

The actuator 2 will be described below with reference to fig. 3A to 19C. The actuator 2 is an actuator that extends and contracts the telescopic arm 14 (see fig. 1 and 2A to 2E).

The actuator 2 includes a telescopic cylinder 3 and a pin moving module 4. The actuator 2 is disposed in the internal space of the distal end arm element 141 in the contracted state (the state shown in fig. 2A) of the telescopic arm 14.

< Telescopic cylinder >

The telescopic cylinder 3 includes a rod member 31 (also referred to as a "fixed-side member". refer to fig. 2A to 2E) and a cylinder member 32 (also referred to as a "movable-side member"). The telescopic cylinder 3 moves an arm element (for example, the front arm element 141 or the intermediate arm element 142) coupled to the cylinder member 32 via cylinder coupling pins 454a and 454b described later in the telescopic direction. The structure of the telescopic cylinder 3 is substantially the same as that of a conventionally known telescopic cylinder, and therefore, a detailed description thereof is omitted.

< Pin moving Module >

The pin moving module 4 includes a housing 40, an electric motor 41, a brake mechanism 42, a transmission mechanism 43, a position information detection device 44, a cylinder connection mechanism 45, an arm connection mechanism 46, and a lock mechanism 47 (see fig. 7).

Hereinafter, each member constituting the actuator 2 will be described with reference to a state in which the actuator 2 is incorporated. In the explanation of the actuator 2, the orthogonal coordinate system (X, Y, Z) shown in each figure is used. However, the arrangement of each part constituting the actuator 2 is not limited to the arrangement of the present embodiment.

In the orthogonal coordinate system shown in each figure, the X direction coincides with the telescopic direction of the telescopic arm 14 in a state of being mounted on the mobile crane 1. The X direction + side is also referred to as "extension direction in the expansion and contraction direction". The X-direction-side is also referred to as "contraction direction in the expansion and contraction direction". The Z direction coincides with the vertical direction of the mobile crane 1, for example, in a state where the heave angle of the telescopic boom 14 is zero (also referred to as a "collapsed state of the telescopic boom 14"). The Y direction coincides with the vehicle width direction of the mobile crane 1, for example, in a state where the telescopic arm 14 is directed forward. However, the Y direction and the Z direction are not limited to the above directions as long as they are 2 directions orthogonal to each other.

< outer case >

The housing 40 is fixed to the cylinder part 32 of the telescopic cylinder 3. The housing 40 accommodates the cylinder connection mechanism 45 and the arm connection mechanism 46 in an internal space. The housing 40 supports the electric motor 41 via a transmission mechanism 43. Further, the housing 40 also supports a brake mechanism 42 described later. Such a housing 40 has the above-described elements as a unit. Such a structure contributes to downsizing, improvement in productivity, and improvement in system reliability of the pin moving module 4.

Specifically, the housing 40 includes a box-shaped first housing element 400 and a box-shaped second housing element 401.

The first housing element 400 accommodates a cylinder coupling mechanism 45 described later in an internal space. In the first housing element 400, the lever member 31 is inserted in the X direction. An end portion of the cylinder member 32 is fixed to a side wall of the first housing element 400 on the X direction + side (left side in fig. 4 and right side in fig. 7).

The first housing element 400 has through holes 400a and 400B in the side walls on both sides in the Y direction (see fig. 3B and 7). A pair of cylinder coupling pins 454a and 454b of the cylinder coupling mechanism 45 are inserted into the through holes 400a and 400b, respectively.

The second housing element 401 is provided on the Z direction + side of the first housing element 400. The second housing element 401 accommodates an arm coupling mechanism 46 described later in an internal space. A transmission shaft 432 (see fig. 8) of a transmission mechanism 43 described later is inserted in the X direction into the second housing element 401.

The second housing element 401 has through holes 401a and 401B in the side walls on both sides in the Y direction (see fig. 3B and 7). The pair of second rack levers 461a and 461b of the arm connecting mechanism 46 are inserted into the through holes 401a and 401b, respectively.

< electric Motor >

The electric motor 41 corresponds to an example of an electric drive source, and is supported by the housing 40 via a speed reducer 431 of the transmission mechanism 43. Specifically, the electric motor 41 is disposed around the cylinder member 32 (for example, on the Z direction + side) and around the second housing element 401 (for example, on the X direction-side) in a state where the output shaft (not shown) is parallel to the X direction (also referred to as "longitudinal direction of the cylinder member 32"). Such a configuration contributes to miniaturization of the pin moving module 4 in the Y direction and the Z direction.

The electric motor 41 is connected to, for example, a power supply device 61 (see fig. 16A to 16D) provided in the turntable 12 via a cable for supplying power. The electric motor 41 is connected to a control unit 44b (see fig. 1) provided in the turntable 12, for example, via a cable for transmitting a control signal.

Each of the cables described above can be wound and unwound by a take-up reel provided outside the proximal end portion of the telescopic arm 14 or on the turn table 12 (see fig. 1).

The electric motor 41 is provided with a manual operation unit 410 (see fig. 3B) that can be operated by a manual handle (not shown). The manual operation unit 410 is used to manually perform the state transition of the pin moving module 4. In the event of a failure or the like, if the manual operation portion 410 is rotated by the manual knob, the output shaft of the electric motor 41 rotates, and the state of the pin moving module 4 is shifted.

Further, the number of the electric motors may be single or plural (for example, 2). When the electric motor is a single motor, the cylinder coupling mechanism 45 and the arm coupling mechanism 46 are operated by 1 electric motor 41 as in the present embodiment. In the case where there are a plurality of electric motors (for example, 2 electric motors), the cylinder coupling mechanism 45 may be operated by a first electric motor (not shown), and the arm coupling mechanism 46 may be operated by a second electric motor (not shown).

In the present embodiment, the electric drive source is the electric motor 41 described above. However, the electric drive source is not limited to the electric motor. For example, the electric drive source may be various drive sources that generate drive force based on energization from a power source.

< brake mechanism >

The brake mechanism 42 applies a braking force to the electric motor 41. The brake mechanism 42 prevents rotation of the output shaft of the electric motor 41 in a stopped state of the electric motor 41. Thus, the pin movement module 4 is maintained in a stopped state of the electric motor 41.

When an external force of a predetermined magnitude acts on the cylinder coupling mechanism 45 or the arm coupling mechanism 46 during braking, the braking mechanism 42 can allow rotation (i.e., sliding) of the electric motor 41. Such a configuration contributes to preventing damage to the electric motor 41 and the gears constituting the actuator 2. In the case of such a configuration, for example, a friction brake can be used as the brake mechanism 42.

Specifically, the brake mechanism 42 operates in a contracted state of the cylinder coupling mechanism 45 or a contracted state of the arm coupling mechanism 46, which will be described later, and maintains the states of the cylinder coupling mechanism 45 and the arm coupling mechanism 46.

The brake mechanism 42 is disposed at a stage before a transmission mechanism 43 described later. Specifically, the brake mechanism 42 is disposed coaxially with the output shaft of the electric motor 41 on the X-direction side of the electric motor 41 (i.e., on the opposite side of the electric motor 41 from the transmission mechanism 43) (see fig. 3B).

Such a configuration contributes to miniaturization of the pin moving module 4 in the Y direction and the Z direction. Further, the preceding stage means: the transmission path through which the power of the electric motor 41 is transmitted to the cylinder coupling mechanism 45 or the arm coupling mechanism 46 is located on the upstream side (on the side closer to the electric motor 41). On the other hand, the rear stage is located on the downstream side (the side away from the electric motor 41) in the transmission path through which the power of the electric motor 41 is transmitted to the cylinder coupling mechanism 45 or the arm coupling mechanism 46.

The structure in which the brake mechanism 42 is disposed at the front stage of the transmission mechanism 43 is configured such that the braking torque required to maintain the stopped state of the electric motor 41 is smaller than the structure in which the brake mechanism 42 is disposed at the rear stage of the transmission mechanism 43 (speed reducer 431 described later). For this reason, the configuration in which the brake mechanism 42 is disposed at the front stage of the transmission mechanism 43 contributes to downsizing of the brake mechanism 42.

The brake mechanism 42 may be a mechanical or electromagnetic brake device. The position of the brake mechanism 42 is not limited to the position of the present embodiment.

< transfer mechanism >

The transmission mechanism 43 transmits the power (i.e., rotational motion) of the electric motor 41 to the cylinder connection mechanism 45 and the arm connection mechanism 46. The transmission mechanism 43 includes a speed reducer 431 and a transmission shaft 432 (see fig. 8).

The speed reducer 431 reduces the rotation of the electric motor 41 and transmits the rotation to the transmission shaft 432. The speed reducer 431 is, for example, a planetary gear mechanism housed in a speed reducer case 431 a. The speed reducer 431 is provided coaxially with the output shaft of the electric motor 41. Such a configuration contributes to miniaturization of the pin moving module 4 in the Y direction and the Z direction.

The X-direction-side end of the transmission shaft 432 is connected to an output shaft (not shown) of the reducer 431. In this state, the transmission shaft 432 rotates together with the output shaft of the speed reducer 431. The transmission shaft 432 extends in the X direction and is inserted through the housing 40 (specifically, the second housing element 401). The transmission shaft 432 may be integrated with the output shaft of the speed reducer 431.

The X-direction + side end of the transmission shaft 432 protrudes further toward the X-direction + side than the housing 40. A position information detection device 44, which will be described later, is provided at the X direction + side end of the transmission shaft 432.

< position information detecting device >

The position information detecting device 44 detects information on the positions of the pair of cylinder coupling pins 454a and 454b and the pair of arm coupling pins 144a (the pair of arm coupling pins 144 b. the same applies hereinafter) based on the output (for example, rotation of the output shaft) of the electric motor 41. The position-related information may be, for example, the amount of movement of the pair of cylinder connecting pins 454a and 454b or the pair of arm connecting pins 144a from the reference position (the position shown in fig. 18A and 19A). The positions of the pair of cylinder coupling pins 454a and 454b shown in fig. 18A and 19A are defined as reference positions of the cylinder coupling pins 454a and 454 b. The positions of the pair of arm connecting pins 144a shown in fig. 18A and 19A are defined as reference positions of the arm connecting pins 144 a.

Specifically, the position information detecting device 44 detects information on the positions of the pair of cylinder connecting pins 454a and 454b in an engaged state (for example, a state shown in fig. 2A) or a disengaged state (for example, a state shown in fig. 2E) of the pair of cylinder connecting pins 454a and 454b and the pair of cylinder pin receiving portions 141a of the arm element (for example, the distal end arm element 141).

The position information detecting device 44 detects information on the positions of the pair of arm connecting pins 144a in an engaged state (for example, the state shown in fig. 2A and 2D) or a disengaged state (for example, the state shown in fig. 2B) between the pair of arm connecting pins 144a and the pair of first arm pin receiving portions 142B (which may be the pair of second arm pin receiving portions 142 c) of the arm element (for example, the intermediate arm element 142).

The information on the positions of the pair of cylinder connecting pins 454a and 454b and the pair of arm connecting pins 144a and 144b detected in this manner is used for various controls of the actuator 2 including, for example, the operation control of the electric motor 41.

The positional information detection device 44 includes a detection unit 44a and a control unit 44b (see fig. 18A and 18A).

The detection unit 44a is, for example, a rotary encoder, and outputs information (for example, a pulse signal or a code signal) according to the amount of rotation of the output shaft of the electric motor 41. The output mode of the rotary encoder is not particularly limited, and may be an incremental mode in which a pulse signal (relative angle signal) corresponding to the amount of rotation (rotation angle) from the measurement start position is output, or an absolute mode in which a code signal (absolute angle signal) corresponding to an absolute angular position with respect to the reference point is output.

If the detection unit 44a is an absolute rotary encoder, the position information detection device 44 can detect information on the positions of the pair of cylinder coupling pins 454a and 454b and the pair of arm coupling pins 144a even when the control unit 44b returns from the non-energized state to the energized state.

The detection portion 44a may be provided to the output shaft of the electric motor 41. The detection portion 44a may be provided to a rotating member (e.g., a rotating shaft, a gear, etc.) that rotates together with the output shaft of the electric motor 41. Specifically, in the present embodiment, the detection unit 44a is provided at the end of the transmission shaft 432 on the + side in the X direction. In other words, in the present embodiment, the detection unit 44a is provided at a later stage (i.e., on the + side in the X direction) than the speed reducer 431.

In the present embodiment, the detection unit 44a outputs information corresponding to the amount of rotation of the transmission shaft 432. In the present embodiment, a rotary encoder capable of obtaining a sufficient resolution with respect to the rotation speed (rotation speed) of the transmission shaft 432 is used as the detection unit 44 a. Since the first missing gear 450 of the cylinder coupling mechanism 45 and the second missing gear 460 of the arm coupling mechanism 46, which will be described later, are fixed to the transmission shaft 432, the output information of the detection unit 44a is also information corresponding to the rotation amounts of the first missing gear 450 and the second missing gear 460.

The detection unit 44a having the above configuration transmits the detection value to the control unit 44 b. The control unit 44b that has acquired this information calculates information relating to the positions of the pair of cylinder coupling pins 454a and 454b or the pair of arm coupling pins 144a based on the acquired information. Then, the control unit 44b controls the electric motor 41 based on the calculation result.

The control unit 44b is, for example, a vehicle-mounted computer including an input terminal, an output terminal, a CPU, a memory, and the like. The control unit 44b calculates information on the positions of the pair of cylinder coupling pins 454a and 454b or the arm coupling pin 144a based on the output of the detection unit 44 a.

Specifically, for example, the control unit 44b calculates the information on the positions of the pair of cylinder coupling pins 454a and 454b and the pair of arm coupling pins 144a using data (a table, a map, or the like) indicating the correlation between the output of the detection unit 44a and the information on the positions (for example, the amount of movement from the reference position).

When the output of the detection unit 44a is the code signal, the information on the position is calculated based on data (table, map, etc.) indicating the correlation between each code signal and the amount of movement from the reference position of the pair of cylinder coupling pins 454a, 454b and the pair of arm coupling pins 144 a.

The control unit 44b is provided in the turntable 12. However, the position of the control unit 44b is not limited to the turntable 12. The control unit 44b may be provided in a cartridge (not shown) in which the detection unit 44a is disposed, for example.

The position of the detection unit 44a is not limited to the position of the present embodiment. For example, the detection unit 44a may be disposed at a stage (i.e., X direction-side) before the speed reducer 431. That is, the detection unit 44a may acquire information to be transmitted to the control unit 44b based on the rotation of the electric motor 41 before being decelerated by the speed reducer 431. The configuration in which the detection unit 44a is disposed at the front stage of the speed reducer 431 has a higher resolution of the detection unit 44a than the configuration in which the detection unit 44a is disposed at the rear stage of the speed reducer 431.

The detection unit 44a is not limited to the rotary encoder described above. For example, the detection unit 44a may be a limit switch. The limit switch is disposed at a later stage than the speed reducer 431. Such a limit switch is mechanically operated based on the output of the electric motor 41. Alternatively, the detection unit 44a may be a proximity sensor. The proximity sensor is disposed at a later stage than speed reducer 431. The proximity sensor is disposed opposite to a member that rotates based on the output of the electric motor 41. Such a proximity sensor outputs a signal based on a distance from the rotating member. Then, the control unit 44b controls the operation of the electric motor 41 based on the output of the limit switch or the proximity sensor.

< cylinder connecting mechanism >

The cylinder coupling mechanism 45 operates based on the power (i.e., rotational motion) of the electric motor 41 in accordance with an example of the operating portion, and changes states between an expanded state (also referred to as a "first state". see fig. 8 and 12) and a contracted state (also referred to as a "second state". see fig. 13).

In the expanded state, a pair of cylinder coupling pins 454a and 454b, which will be described later, and a pair of cylinder pin receiving portions 141a of the arm element (for example, the distal end arm element 141) are brought into an engaged state (also referred to as an "inserted state of the cylinder pin"). In this engaged state, the arm element and the cylinder member 32 are connected to each other.

On the other hand, in the contracted state, the pair of cylinder coupling pins 454a and 454b and the pair of cylinder pin receiving portions 141a (see fig. 2A to 2E) are in a disengaged state (the state shown in fig. 2E is also referred to as a "cylinder pin extraction state"). In this disengaged state, the arm element and the cylinder member 32 are in a non-coupled state.

Hereinafter, a specific configuration of the cylinder coupling mechanism 45 will be described. As shown in fig. 9 to 13, the cylinder coupling mechanism 45 includes a first toothless gear 450, a first rack bar 451, a first gear mechanism 452, a second gear mechanism 453, a pair of cylinder coupling pins 454a and 454b, and a first biasing mechanism 455. Each of the elements 450, 451, 452, and 453 corresponds to an example of a component of the first drive mechanism.

In the present embodiment, a pair of cylinder coupling pins 454a and 454b are incorporated into the cylinder coupling mechanism 45. However, the pair of cylinder coupling pins 454a and 454b may be provided independently of the cylinder coupling mechanism 45.

< first gear lacking gear >

The first missing-tooth gear 450 (also referred to as "opening and closing gear") has a substantially circular-disk shape. The first missing-tooth gear 450 has a first tooth portion 450a (see fig. 9) on a part of the outer peripheral surface. The first toothless gear 450 is fitted around the transmission shaft 432 and rotates together with the transmission shaft 432.

The first missing gear 450 and the second missing gear 460 (see fig. 8) of the arm coupling mechanism 46 together constitute a switching gear. The switch gear selectively transmits the power of the electric motor 41 to one of the cylinder connection mechanism 45 and the arm connection mechanism 46.

In the present embodiment, the first and second missing-teeth gears 450 and 460 as the open/close gears are incorporated into the cylinder connecting mechanism 45 as the first connecting mechanism and the arm connecting mechanism 46 as the second connecting mechanism, respectively. However, the switch gear may be provided independently of the first coupling mechanism and the second coupling mechanism.

In the following description, the rotation direction of the first missing-tooth gear 450 (indicated by arrow F in fig. 18A to 18C) when the cylinder coupling mechanism 45 shifts from the expanded state (see fig. 8, 12, and 18A) to the contracted state (see fig. 13 and 18C)₂The illustrated direction) is the "front side" in the rotational direction of the first missing-tooth gear 450.

On the other hand, the direction of rotation of the first missing-tooth gear 450 when the state is shifted from the contracted state to the expanded state (indicated by arrow F in fig. 18A to 18C)₁The illustrated direction) is the "rear side" in the rotational direction of the first missing-tooth gear 450.

Of the convex portions constituting the first tooth portion 450a, the convex portion provided most forward in the rotation direction of the first missing-tooth gear 450 is a positioning tooth (not shown).

< first rack bar >

The first rack bar 451 moves in the longitudinal direction thereof (also referred to as the "Y direction") in accordance with the rotation of the first toothless gear 450. The first rack bar 451 is located closest to the Y direction side in the expanded state (see fig. 8 and 12). On the other hand, the first rack bar 451 is located closest to the Y direction + side in the contracted state (see fig. 13).

When the state is shifted from the expanded state to the contracted state, if the first toothless gear 450 rotates to the front side in the rotation direction, the first rack bar 451 moves to the + side in the Y direction (also referred to as "one of the longitudinal directions").

On the other hand, when the state is shifted from the contracted state to the expanded state, if the first toothless gear 450 rotates to the rear side in the rotational direction, the first rack bar 451 moves to the Y-direction side (also referred to as the "other side in the longitudinal direction"). Hereinafter, a specific structure of the first rack bar 451 will be described.

The first rack bar 451 is, for example, a shaft member that is long in the Y direction, and is disposed between the first toothless gear 450 and the rod member 31. In this state, the longitudinal direction of the first rack bar 451 coincides with the Y direction.

The first rack bar 451 has a first rack tooth portion 451a on a surface thereof on the side closer to the first missing-tooth gear 450 (also referred to as "Z direction + side") (see fig. 8). The first rack tooth portion 451a engages with the first tooth portion 450a of the first missing-tooth gear 450 only at the time of the above state transition.

In the expanded state shown in fig. 8 and 10, a first end surface (not shown) on the Y direction + side of the first rack tooth portion 451a abuts against a positioning tooth (not shown) of the first tooth portion 450a of the first missing-tooth gear 450 or faces each other in the Y direction with a slight gap therebetween.

In the expanded state, if the first toothless gear 450 rotates forward in the rotation direction, the positioning teeth 450b press the first end surface 451d toward the Y direction + side, and the first rack bar 451 moves toward the Y direction + side.

Then, a tooth portion existing on the rear side in the rotational direction than the positioning teeth in the first tooth portion 450a meshes with the first rack tooth portion 451 a. As a result, the first rack bar 451 moves to the + side in the Y direction in accordance with the rotation of the first toothless gear 450.

Further, when the first missing-tooth gear 450 rotates to the rear side in the rotational direction from the expanded state shown in fig. 8, the first rack tooth portion 451a does not mesh with the first tooth portion 450a of the first missing-tooth gear 450.

The first rack bar 451 has a second rack tooth portion 451b and a third rack tooth portion 451c on a surface thereof on a side away from the first missing-tooth gear 450 (also referred to as "Z-direction side") (see fig. 8). The second rack tooth portion 451b is engaged with a first gear mechanism 452 described later. On the other hand, the third rack tooth portion 451c meshes with a second gear mechanism 453 described later.

< first gear mechanism >

The first gear mechanism 452 includes a plurality of (3 in the present embodiment) gear elements 452a, 452b, and 452c (see fig. 8) each of which is a spur gear. Specifically, the gear element 452a meshes with the second rack toothed portion 451b of the first rack bar 451 and the gear element 452 b. In the expanded state (see fig. 8 and 12), the gear element 452a meshes with the tooth portion of the Y-direction + side end portion or the portion near the end portion of the second rack tooth portion 451b of the first rack bar 451.

Gear element 452b meshes with gear element 452a and gear element 452 c.

The gear element 452c meshes with the gear element 452b and a pin-side rack tooth portion 454c of one cylinder coupling pin 454a described later. In the expanded state, the gear element 452c meshes with the Y-direction side end portion of the pin-side rack tooth portion 454c (see fig. 8) of the cylinder connecting pin 454 a.

< second gear mechanism >

The second gear mechanism 453 includes a plurality of (2 in the case of the present embodiment) gear elements 453a, 453b (see fig. 8) each of which is a flat gear. Specifically, the gear element 453a meshes with the third rack tooth portion 451c and the gear element 453b of the first rack bar 451. In the expanded state, the gear element 453a meshes with the end portion of the third rack tooth portion 451c of the first rack bar 451 on the + side in the Y direction.

The gear element 453b meshes with the gear element 453a and a pin-side rack gear portion 454d (see fig. 8) of the other cylinder connecting pin 454b described later. In the expanded state, the gear element 453b meshes with the end portion on the Y direction + side of the pin-side rack tooth portion 454d of the other cylinder coupling pin 454 b.

In the present embodiment, the rotation direction of the gear element 452c of the first gear mechanism 452 is opposite to the rotation direction of the gear element 453b of the second gear mechanism 453.

< cylinder connecting pin >

The center axes of the pair of cylinder connecting pins 454a and 454b are aligned in the Y direction and are coaxial with each other. In the following description of the pair of cylinder connecting pins 454a and 454b, the distal end portion refers to the end portion on the side away from each other, and the proximal end portion refers to the end portion on the side close to each other.

The pair of cylinder coupling pins 454a and 454b have pin-side rack teeth 454c and 454d (see fig. 8) on the outer peripheral surface, respectively. The pin-side rack teeth 454c of one (also referred to as "Y-direction + side") cylinder coupling pin 454a mesh with the gear element 452c of the first gear mechanism 452.

The cylinder connecting pin 454a moves in its own axial direction (i.e., Y direction) in accordance with the rotation of the gear element 452c in the first gear mechanism 452. Specifically, when the state is shifted from the contracted state to the expanded state, one cylinder coupling pin 454a moves to the + side in the Y direction (also referred to as "second direction"). On the other hand, when the state is shifted from the expanded state to the contracted state, the cylinder connecting pin 454a moves to the Y-direction side (also referred to as "first direction").

The pin-side rack tooth portion 454d of the other cylinder coupling pin 454b (also referred to as "Y-direction-side") meshes with the gear element 453b of the second gear mechanism 453. The other cylinder connecting pin 454b moves in its own axial direction (i.e., Y direction) in accordance with the rotation of the gear element 453b in the second gear mechanism 453.

Specifically, the other cylinder coupling pin 454b moves to the Y-direction side (also referred to as "second direction") when the state is shifted from the contracted state to the expanded state. On the other hand, the other cylinder connecting pin 454b moves to the Y direction + side (also referred to as "first direction") when the state is shifted from the expanded state to the contracted state. That is, in the state transition described above, the pair of cylinder coupling pins 454a and 454b move in the Y direction in the opposite directions to each other.

The pair of cylinder connecting pins 454a and 454b are inserted into the through holes 400a and 400b of the first housing element 400, respectively. In this state, the tip end portions of the pair of cylinder coupling pins 454a and 454b protrude outward of the first housing element 400.

< first force application mechanism >

The first biasing mechanism 455 automatically returns the cylinder coupling mechanism 45 to the expanded state when the electric motor 41 is in the non-energized state in the contracted state of the cylinder coupling mechanism 45. Therefore, the first biasing mechanism 455 biases the pair of cylinder connecting pins 454a and 454b in the direction away from each other. The first biasing mechanism 455 may bias the cylinder coupling pins 454a and 454b directly or via another member. The first force application mechanism 455 may be omitted. In this case, the cylinder coupling mechanism 45 can be shifted from the contracted state to the expanded state based on the power of the electric motor 41.

Specifically, the first force application mechanism 455 is constituted by a pair of coil springs 455a and 455b (see fig. 8). The pair of coil springs 455a, 455b urge the pair of cylinder coupling pins 454a, 454b toward the front end side, respectively. The pair of coil springs 455a, 455b correspond to an example of the first urging mechanism, respectively.

When the brake mechanism 42 is operating, the cylinder connection mechanism 45 does not automatically return.

< Circuit >

Next, the circuit 6 will be described with reference to fig. 16A to 16D. The circuit 6 is a so-called H-bridge circuit. The circuit 6 is switched to a plurality of states under the control of the control unit 44 b. The various states implemented by the circuit 6 are left to be described later.

The circuit 6 includes a power supply device 61, a first switch 62, a second switch 63, a third switch 64, a fourth switch 65, and an electric motor 41.

The power supply device 61 is provided on the turntable 12 (see fig. 1), for example.

The first switch 62 is, for example, a transistor. The first switch 62 is provided on the first line 6L 1. The first switch 62 can be controlled by the control unit 44B (see fig. 1) to be in either an ON state (the state shown in fig. 16B) or an OFF state (the states shown in fig. 16A, 16C, and 16D).

The second switch 63 is, for example, a transistor. The second switch 63 is provided in series with the first switch 62 in the first line 6L 1. The second switch 63 is provided on the downstream side in the current direction of the first line 6L1 than the first switch 62. The second switch 63 can be controlled by the control unit 44B (see fig. 1) to be in either an ON state (the state shown in fig. 16C and 16D) or an OFF state (the state shown in fig. 16A and 16B).

The third switch 64 is, for example, a transistor. The third switch 64 is disposed on the second line 6L 2. The second line 6L2 is connected in parallel with the first line 6L 1. The third switch 64 can be controlled by the control unit 44B (see fig. 1) to be in either an ON state (the state shown in fig. 16C) or an OFF state (the states shown in fig. 16A, 16B, and 16D).

The fourth switch 65 is, for example, a transistor. The fourth switch 65 is arranged in series with the third switch 64 in the second line 6L 2. The fourth switch 65 is disposed on the more downstream side in the current direction than the third switch 64 in the second line 6L 2. The fourth switch 65 can be controlled by the control unit 44B (see fig. 1) to be in either an ON state (the state shown in fig. 16B and 16D) or an OFF state (the state shown in fig. 16A and 16C).

The electric motor 41 has the structure described above. The electric motor 41 is provided in the third line 6L 3. The third line 6L3 connects the portion between the first switch 62 and the second switch 63 in the first line 6L1 and the portion between the third switch 64 and the fourth switch 65 in the second line 6L 2.

The circuit 6 described above can obtain the non-energized state shown in fig. 16A, the first driving state shown in fig. 16B, the second driving state shown in fig. 16C, and the braking state shown in fig. 16D.

< non-energized state >

The non-energized state of the circuit 6 is a state in which the connection between the electric motor 41 and the power supply device 61 is released (also referred to as a "state in which the power supply from the power supply device 61 to the electric motor 41 is stopped"), as shown in fig. 16A. In the non-energized state of the circuit 6, the switches 62, 63, 64, and 65 are in the OFF state.

< first drive State >

The first driving state of the circuit 6 is a state in which the electric motor 41 and the power supply device 61 are connected (also referred to as a "state in which power supply from the power supply device 61 to the electric motor 41 is permitted"), as shown in fig. 16B. In the first driving state of the circuit 6, a current flows through the circuit shown by the thick line in fig. 16B.

In a first driving state of the circuit 6, a current in a first direction flows through the electric motor 41. The first direction is a direction from the first line 6L1 toward the second line 6L 2. In the first driving state of the circuit 6, the electric motor 41 is driven in the first direction (arrow F in fig. 18A to 18C)₂Direction of) is rotated. In the first driving state of the circuit 6, the first switch 62 and the fourth switch 65 are in the ON state. In the first driving state of the circuit 6, the second switch 63 and the third switch 64 are in the OFF state. The first driving state corresponds to an example of the circuit driving state.

< second drive State >

The second driving state of the circuit 6 is a state in which the electric motor 41 and the power supply device 61 are connected (also referred to as a "state in which power supply from the power supply device 61 to the electric motor 41 is permitted"), as shown in fig. 16C. In the second driving state of the circuit 6, a current flows through the circuit shown by the thick line in fig. 16C.

In a second driving state of the circuit 6, a current in a second direction flows through the electric motor 41. The second direction is a direction from the second line 6L2 toward the first line 6L 1. In the second driving state of the circuit 6, the electric motor 41 is driven in the second direction (arrow F in fig. 19A to 19C)₁Direction) rotation (reversal). In the second driving state of the circuit 6, the second switch 63 and the third switch 64 are in the ON state. In the second driving state of the circuit 6, the first switch 62 and the fourth switch 65 are in the OFF state. The second driving state corresponds to an example of the circuit driving state.

< braking State >

As shown in fig. 16D, the braking state of the electric circuit 6 is a state in which the connection between the electric motor 41 and the power supply device 61 is released (the power supply from the power supply device 61 to the electric motor 41 is stopped), and a closed circuit 66 (a portion shown by a thick line in fig. 16D) is formed in the electric circuit 6. That is, the circuit 6 has a closed circuit 66 in the braking state. The closed circuit 66 is a closed circuit including the electric motor 41, the second switch 63, and the fourth switch 65.

In the braking state of the circuit 6, the first switch 62 and the third switch 64 are in the OFF state. In the braking state of the circuit 6, the second switch 63 and the fourth switch 65 are turned ON. The operation of the circuit 6 is described later.

< actuation of cylinder connecting mechanism >

An example of the operation of the cylinder coupling mechanism 45 will be briefly described with reference to fig. 18A to 18C. Fig. 18A to 18C are schematic diagrams for explaining the operation of the cylinder connecting mechanism 45.

Fig. 18A is a schematic diagram showing an expanded state of the cylinder coupling mechanism 45 and an engaged state of the pair of cylinder coupling pins 454a and 454b with the pair of cylinder pin receiving portions 141a of the front end arm element 141. Fig. 18B is a schematic diagram showing a state in the process of the state transition of the cylinder coupling mechanism 45 from the expanded state to the contracted state. Fig. 18C is a schematic diagram showing a contracted state of the cylinder coupling mechanism 45 and a disengaged state of the pair of cylinder coupling pins 454a and 454b and the pair of cylinder pin receiving portions 141a of the front end arm element 141.

The cylinder coupling mechanism 45 is configured to shift between an expanded state (see fig. 8, 12, and 18A) and a contracted state (see fig. 13 and 18C) based on power (i.e., rotational motion) of the electric motor 41. The operation of each section when the cylinder coupling mechanism 45 shifts from the expanded state to the contracted state will be described below with reference to fig. 18A to 18C.

In fig. 18A to 18C, the first and second missing-teeth gears 450 and 460 are schematically illustrated as an integrated missing-teeth gear. Hereinafter, for convenience of explanation, the integrated type gear with missing teeth will be described as the first gear with missing teeth 450. In fig. 18A to 18C, a lock mechanism 47 described later is omitted. Further, the position of the first missing-tooth gear 450 shown in fig. 18A is defined as a reference position of the first missing-tooth gear 450.

When the cylinder coupling mechanism 45 shifts from the expanded state to the contracted state, the control unit 44B switches the circuit 6 to the first driving state (see fig. 16B). The power of the electric motor 41 is transmitted to the pair of cylinder coupling pins 454a and 454b through the following first and second paths.

The first path is a path of the first toothless gear 450 → the first rack bar 451 → the first gear mechanism 452 → one cylinder coupling pin 454 a.

On the other hand, the second path is the path of the first toothless gear 450 → the first rack bar 451 → the second gear mechanism 453 → the other cylinder connecting pin 454 b.

Specifically, first, in the first path and the second path, the first missing-tooth gear 450 is advanced in the rotation direction (indicated by arrow F in fig. 18A) by the power of the electric motor 41₂The direction shown) is rotated.

In the first path and the second path, if the first toothless gear 450 rotates forward in the rotation direction, the first rack bar 451 moves to the Y direction + side (the right side in fig. 18A to 18C) in accordance with the rotation.

Then, in the first path, if the first rack bar 451 moves to the + side in the Y direction, the cylinder connecting pin 454a on one side moves to the-side in the Y direction (the left side in fig. 18A to 18C) via the first gear mechanism 452.

On the other hand, in the second path, if the first rack bar 451 moves to the Y direction + side, the other cylinder connecting pin 454b moves to the Y direction + side via the second gear mechanism 453. That is, when the state is shifted from the expanded state to the contracted state, one cylinder coupling pin 454a and the other cylinder coupling pin 454b move in directions approaching each other.

The position information detecting device 44 detects that the pair of cylinder connecting pins 454a and 454b are separated from the pair of cylinder pin receiving portions 141a of the front arm element 141 and moved to predetermined positions (for example, positions shown in fig. 2E and 18C). Then, based on the detection result, the control unit 44b stops the operation of the electric motor 41.

Further, if the brake mechanism 42 is released in the non-energized state of the electric motor 41, the cylinder coupling mechanism 45 automatically performs a transition from the contracted state to the expanded state (i.e., a transition from fig. 18C to fig. 18A) based on the biasing force of the first biasing mechanism 455. At this time, the one cylinder coupling pin 454a and the other cylinder coupling pin 454b move in directions away from each other.

When the cylinder coupling mechanism 45 is shifted from the contracted state to the expanded state, the control unit 44b switches the circuit 6 to the braking state (see fig. 16D). At this time, the electric motor 41 idles due to the biasing force of the first biasing mechanism 455. Then, the electric motor 41 generates power based on this idling. The electric current generated by the electric motor 41 is returned to the electric motor 41 through the closed circuit 66. Then, based on the current returned to the electric motor 41, a lorentz force is generated in the electric motor 41. The lorentz force acts as a braking force on the electric motor 41. As a result, the one cylinder coupling pin 454a and the other cylinder coupling pin 454b are stopped at the reference positions shown in fig. 18A based on the braking force. The detailed operation of the circuit 6 is described later.

The position information detecting device 44 detects that the pair of cylinder connecting pins 454a and 454b are engaged with the pair of cylinder pin receiving portions 141a of the front end arm element 141 and have moved to a predetermined position (for example, the position shown in fig. 2A and 18A). The detection result is used for controlling the next operation of the actuator 2.

< arm connecting mechanism >

The arm coupling mechanism 46 corresponds to an example of the operation portion, and performs state transition between an expanded state (also referred to as a "first state". see fig. 8 and 13) and a contracted state (also referred to as a "second state". see fig. 12) based on rotation of the electric motor 41.

In the expanded state, the arm coupling mechanism 46 is in one of an engaged state and a disengaged state with respect to the arm coupling pin (for example, the pair of arm coupling pins 144 a).

The arm coupling mechanism 46 is configured to shift from the expanded state to the contracted state in a state of being engaged with the arm coupling pin, thereby disengaging the arm coupling pin from the arm element.

Further, the arm coupling mechanism 46 is configured to shift from the contracted state to the expanded state in a state of being engaged with the arm coupling pin, thereby engaging the arm coupling pin with the arm element.

Hereinafter, a specific configuration of the arm coupling mechanism 46 will be described. As shown in fig. 8, the arm coupling mechanism 46 includes: a second missing-tooth gear 460, a pair of second rack bars 461a, 461b, a synchronizing gear 462 (see fig. 18A to 18C), and a second urging mechanism 463. The elements 460, 461a, 461b, and 462 correspond to an example of a component of the second drive mechanism. The pair of arm connecting pins 144a and 144b also correspond to an example of a component of the second drive mechanism.

< second gear with missing teeth >

The second missing-tooth gear 460 (also referred to as "opening and closing gear") is substantially disc-shaped, and has a second tooth portion 460a in a part of the outer circumferential surface in the circumferential direction.

The second missing-tooth gear 460 is fitted and fixed to the transmission shaft 432 on the X direction + side with respect to the first missing-tooth gear 450, and rotates together with the transmission shaft 432. The second missing gear 460 may be a missing gear that is integrated with the first missing gear 450, as shown in the schematic diagrams of fig. 14A to 14D, for example.

Thereafter, the second missing gear 460 rotates in the direction (indicated by the arrow F in fig. 8) when the arm coupling mechanism 46 shifts from the expanded state (see fig. 8 and 13) to the contracted state (see fig. 12)₁The illustrated direction) is the "front side" in the rotational direction of the second missing-tooth gear 460.

On the other hand, the rotation direction of the second missing-tooth gear 460 (indicated by arrow F in fig. 8) when the arm coupling mechanism 46 shifts from the contracted state to the expanded state₂The illustrated direction) is the "rear side" in the rotational direction of the second missing-tooth gear 460.

Among the convex portions constituting the second tooth portion 460a, the convex portion disposed most forward in the rotational direction of the second missing-tooth gear 460 is a positioning tooth 460b (see fig. 8).

Fig. 8 is a view of the pin moving module 4 as viewed from the X direction + side. Therefore, in the case of the present embodiment, the front-rear direction in the rotational direction of the second missing gear 460 is opposite to the front-rear direction in the rotational direction of the first missing gear 450.

That is, the rotation direction of the second missing-tooth gear 460 when the arm coupling mechanism 46 shifts from the expanded state to the contracted state is opposite to the rotation direction of the first missing-tooth gear 450 when the cylinder coupling mechanism 45 shifts from the expanded state to the contracted state.

< second rack bar >

The pair of second rack levers 461a, 461b move in the Y direction (also referred to as "axial direction") in accordance with the rotation of the second missing-tooth gear 460. The second rack 461a on one side (also referred to as "X direction + side") and the second rack 461b on the other side (also referred to as "X direction-side") move in opposite directions to each other in the Y direction.

The second rack lever 461a is positioned on the Y-direction side most in the expanded state. The other second rack lever 461b is positioned closest to the Y direction + side in the expanded state.

The second rack lever 461a is positioned closest to the + side in the Y direction in the contracted state. The other second rack lever 461b is positioned closest to the Y direction side in the contracted state.

Further, the movement of the one second rack 461a to the + side in the Y direction and the movement of the other second rack 461b to the-side in the Y direction are regulated by, for example, contact with a stopper surface 48 (see fig. 14D) provided on the housing 40.

Hereinafter, a specific configuration of the pair of second rack bars 461a and 461b will be described. The pair of second rack bars 461a, 461b are shaft members, for example, long in the Y direction, and are arranged in parallel to each other. The pair of second rack bars 461a, 461b are disposed on the Z direction + side of the first rack bar 451, respectively. The pair of second rack bars 461a and 461b are arranged with a synchronizing gear 462 described later as a center in the X direction. The longitudinal direction of each of the pair of second rack bars 461a and 461b coincides with the Y direction.

The pair of second rack bars 461a and 461b have synchronization rack teeth 461e and 461f on the side surfaces facing each other in the X direction, respectively (see fig. 18A to 18C). The synchronizing rack teeth 461e and 461f mesh with the synchronizing gear 462.

When the synchronizing gear 462 rotates, the one second rack lever 461a and the other second rack lever 461b move in the Y direction in opposite directions.

The pair of second rack levers 461a and 461b have locking claw portions 461g and 461h (also referred to as "locking portions". see fig. 8) at the distal end portions, respectively. When the arm connecting pins 144a and 144b are moved, the locking claw portions 461g and 461h engage with pin-side receiving portions 144c (see fig. 8) provided in the arm connecting pins 144a and 144 b.

The second rack lever 461a includes a driving rack tooth portion 461c on a first side surface (a side surface close to the second missing-tooth gear 460) of the second missing-tooth gear 460 (see fig. 8). The driving rack tooth portion 461c meshes with the second tooth portion 460a of the second toothless gear 460.

In the expanded state (see fig. 8), the first end face 461d (end face on the + side in the Y direction) of the driving rack tooth portion 461c abuts against the positioning teeth 460b in the second tooth portion 460a of the second missing-tooth gear 460 or faces each other in the Y direction with a slight gap therebetween.

When the second toothless gear 460 rotates forward in the rotational direction from the expanded state, the positioning teeth 460b press the first end surface 461d toward the Y direction + side. With this pressing, the second rack lever 461a moves in the Y direction + side.

When one of the second rack bars 461a moves to the Y direction + side, the synchronizing gear 462 rotates, and the other second rack bar 461b moves to the Y direction-side (i.e., the side opposite to the one second rack bar 461 a).

< second force application mechanism >

The second biasing mechanism 463 automatically returns the arm coupling mechanism 46 to the expanded state when the electric motor 41 is in the non-energized state in the contracted state of the arm coupling mechanism 46. When the brake mechanism 42 is operating, the arm coupling mechanism 46 does not automatically return. The second biasing mechanism 463 may be omitted. In this case, the arm coupling mechanism 46 can be shifted from the contracted state to the expanded state based on the power of the electric motor 41.

For this reason, the second biasing mechanism 463 biases the pair of second rack levers 461a, 461b in directions away from each other. Specifically, the second biasing mechanism 463 is constituted by a pair of coil springs 463a, 463b (see fig. 18A to 17C). The pair of coil springs 463a, 463b urge the base end portions of the pair of second rack levers 461a, 461b toward the front end side, respectively. The pair of coil springs 463a and 463b correspond to an example of the second urging mechanism.

< action of arm connecting mechanism >

An example of the operation of the arm coupling mechanism 46 will be briefly described with reference to fig. 19A to 19C. Fig. 19A to 19C are schematic diagrams for explaining the operation of the arm connecting mechanism 46.

Fig. 19A is a schematic diagram showing an expanded state of the arm connecting mechanism 46 and an engaged state between the pair of arm connecting pins 144a and the pair of first arm pin receiving portions 142b of the intermediate arm element 142. Fig. 19B is a schematic diagram showing a state in the process of the arm coupling mechanism 46 transitioning from the expanded state to the contracted state. Fig. 19C is a schematic diagram showing a contracted state of the arm coupling mechanism 46 and a disengaged state between the pair of arm coupling pins 144a and the pair of first arm pin receiving portions 142b of the intermediate arm element 142.

The arm coupling mechanism 46 as described above performs state transition between the expanded state (see fig. 19A) and the contracted state (see fig. 19C) based on the power (i.e., rotational motion) of the electric motor 41. The operation of each section when the arm coupling mechanism 46 shifts from the expanded state to the contracted state will be described below with reference to fig. 19A to 19C.

In fig. 19A to 19C, the first and second missing-teeth gears 450 and 460 are schematically illustrated as an integrated missing-teeth gear. Hereinafter, for convenience of explanation, the integrated type gear with missing teeth will be described as the second gear with missing teeth 460. Further, the position of the second missing-tooth gear 460 shown in fig. 19A is defined as a reference position of the second missing-tooth gear 460. In fig. 19A to 19C, a lock mechanism 47 described later is omitted.

When the arm coupling mechanism 46 shifts from the expanded state to the contracted state, the control unit 44b switches the circuit 6 to the second driving state (see fig. 16C). The power (i.e., rotational motion) of the electric motor 41 is transmitted through a path of the second missing-tooth gear 460 → the one second rack bar 461a → the synchronizing gear 462 → the other second rack bar 461 b.

First, in the above path, the second missing gear 460 is located forward in the rotation direction (indicated by arrow F in fig. 8 and 19A to 19C) by the power of the electric motor 41₁The direction shown) is rotated.

If the second missing-tooth gear 460 rotates forward in the rotation direction, the second rack lever 461a on one side moves to the Y direction + side (the right side in fig. 19A to 19C) in accordance with the rotation.

Then, the synchronizing gear 462 rotates in accordance with the movement of the one second rack lever 461a to the + side in the Y direction. Then, the other second rack lever 461b moves in the Y direction-side (left side in fig. 19A to 19C) in accordance with the rotation of the synchronizing gear 462.

When the state is shifted from the expanded state to the contracted state in a state where the pair of second rack levers 461a and 461b are engaged with the pair of arm connecting pins 144a, the pair of arm connecting pins 144a are disengaged from the pair of first arm pin receiving portions 142b of the intermediate arm element 142 (see fig. 19C).

The position information detecting device 44 detects that the pair of arm connecting pins 144a has moved to a predetermined position (for example, the position shown in fig. 2B and 19C) while being separated from the pair of first arm pin receiving portions 142B of the intermediate arm element 142. Then, based on the detection result, the control unit 44b stops the operation of the electric motor 41.

Further, if the brake mechanism 42 is released in the non-energized state of the electric motor 41, the insertion operation of the arm connecting mechanism 46 is automatically performed based on the biasing force of the second biasing mechanism 463 (that is, the state is shifted from fig. 19C to fig. 19A). When the state is shifted, the pair of arm coupling pins 144a move in a direction away from each other.

When the arm coupling mechanism 46 shifts from the contracted state to the expanded state, the control unit 44b switches the circuit 6 to the braking state (see fig. 16D). Then, by switching the circuit 6 to the closed circuit 66, the above-described braking force is generated in the electric motor 41. As a result, the pair of arm coupling pins 144a are stopped at the reference positions shown in fig. 19A based on the braking force. The operation of the circuit 6 is described later.

The position information detecting device 44 detects that the pair of arm connecting pins 144a are engaged with the pair of first arm pin receiving portions 142b of the intermediate arm element 142 and moved to a predetermined position (for example, the position shown in fig. 2A and 19A). The detection result is used for controlling the next operation of the actuator 2.

In the case of the present embodiment, the extracted state of the cylinder connecting pin and the extracted state of the arm connecting pin are prevented from being simultaneously realized in one arm element (for example, the front end arm element 141).

Therefore, the state transition of the cylinder coupling mechanism 45 and the state transition of the arm coupling mechanism 46 do not occur simultaneously.

Specifically, when the first tooth portion 450a of the first missing tooth gear 450 meshes with the first rack tooth portion 451a of the first rack bar 451 in the cylinder coupling mechanism 45, the second tooth portion 460a of the second missing tooth gear 460 does not mesh with the driving rack tooth portion 461c of the one second rack bar 461a in the arm coupling mechanism 46.

Conversely, when the second tooth portion 460a of the second missing gear 460 is meshed with the driving rack tooth portion 461c of the one second rack bar 461a in the arm coupling mechanism 46, the first tooth portion 450a of the first missing gear 450 is not meshed with the first rack tooth portion 451a of the first rack bar 451 in the cylinder coupling mechanism 45.

In the present embodiment, the operating units are the cylinder coupling mechanism 45 and the arm coupling mechanism 46 described above. However, the operation unit is not limited to the cylinder connection mechanism 45 and the arm connection mechanism 46. The operating unit may be any of various mechanisms that operate based on the power of the electric drive source.

< locking mechanism >

As described above, the actuator 2 according to the present embodiment is realized in such a manner that the extraction state of the cylinder connection pin and the extraction state of the arm connection pin are different in one arm element (for example, the front end arm element 141) based on the configurations of the arm connection mechanism 46 and the cylinder connection mechanism 45. Such a configuration can prevent the arm coupling mechanism 46 and the cylinder coupling mechanism 45 from operating simultaneously by the power of the electric motor 41.

In addition to the above configuration, the actuator 2 according to the present embodiment includes the lock mechanism 47, and the lock mechanism 47 prevents the cylinder coupling mechanism 45 and the arm coupling mechanism 46 from simultaneously performing state transition when an external force other than the electric motor 41 acts on the cylinder coupling mechanism 45 (e.g., the first rack bar 451) or the arm coupling mechanism 46 (e.g., the second rack bar 461 a).

The lock mechanism 47 prevents one of the arm coupling mechanism 46 and the cylinder coupling mechanism 45 from operating while the other coupling mechanism is operating. Hereinafter, a specific structure of the lock mechanism 47 will be described with reference to fig. 14A to 14D. Fig. 14A to 14D are schematic diagrams for explaining the structure of the lock mechanism 47.

In fig. 14A to 14D, the missing gear is constituted by an integrated missing gear 49 (also referred to as a "switch gear") in which the first missing gear 450 of the cylinder coupling mechanism 45 and the second missing gear 460 of the arm coupling mechanism 46 are integrally formed. The integrated gear 49 has a substantially disk-like shape and a tooth portion 49a on a part of the outer peripheral surface. The structure of the other portions is the same as that of the present embodiment described above.

The lock mechanism 47 includes a first protrusion 470, a second protrusion 471, and a cam member 472 (also referred to as a "lock-side rotating member").

The first convex portion 470 is provided integrally with the first rack bar 451 of the cylinder coupling mechanism 45. Specifically, the first convex portion 470 is provided at a position adjacent to the first rack toothed portion 451a of the first rack bar 451.

The second protrusion 471 is provided integrally with the second rack lever 461a on one side of the arm coupling mechanism 46. Specifically, the second protrusion 471 is provided adjacent to the driving rack tooth 461c of the second rack lever 461 a.

The cam member 472 is a substantially crescent-shaped plate-like member. Such a cam member 472 has a first cam receiving portion 472a at one end in the circumferential direction. On the other hand, the cam member 472 has a second cam receiving portion 472b at the other end in the circumferential direction.

The cam member 472 can be fitted and fixed to the transmission shaft 432 at a position shifted in the X direction from the position where the integrated toothless gear 49 is fitted and fixed to the transmission shaft. In the present embodiment, the cam member 472 is fitted and fixed between the first and second toothless gears 450, 460. That is, the cam member 472 is provided coaxially with the integrated toothless gear 49. Such a cam member 472 rotates together with the transmission shaft 432. Therefore, the cam member 472 rotates about the central axis of the transmission shaft 432 together with the integrated toothless gear 49.

Further, the cam member 472 may be integrated with the integrated type toothless gear 49. In the present embodiment, the cam member 472 may be integrated with at least one of the first and second missing-teeth gears 450 and 460.

As shown in fig. 14B to 14D and 15A, in a state where the tooth portion 49a of the integrated type gear with no teeth 49 (also, the second tooth portion 460a of the second gear with no teeth 460) meshes with the driving rack tooth portion 461c of the one second rack lever 461a, the first cam receiving portion 472a of the cam member 472 is positioned on the Y direction + side with respect to the first protruding portion 470. At this time, the tooth portion 49a of the integrated type toothless gear 49 does not mesh with the first rack tooth portion 451a of the first rack bar 451.

In this state, the first cam receiving portion 472a and the first projection 470 face each other with a slight gap in the Y direction (see fig. 15A). Thereby, even if an external force on the Y direction + side is applied to the first rack bar 451 (indicated by arrow F in fig. 15A)_aForce in the direction shown) can also be prevented from moving toward the + side in the Y direction of the first rack bar 451.

Specifically, if the first rack bar 451 is applied with the external force F on the + side in the Y direction_aThe first rack bar 451 moves to the + side in the Y direction from the position shown by the two-dot chain line in fig. 15A to the position shown by the solid line. In this state, the first convex portion 470 abuts against the first cam receiving portion 472a, and the first rack bar 451 can be prevented from moving to the + side in the Y direction.

In the state shown in fig. 14B to 14D, the outer peripheral surface of the cam member 472 and the first protruding portion 470 face each other with a slight gap in the Y direction. Thus, even when an external force on the Y direction + side is applied to the first rack bar 451, the first rack bar 451 is prevented from moving in the Y direction + side.

On the other hand, as shown in fig. 15B, in a state where the tooth portion 49a of the integrated type toothless gear 49 (the first tooth portion 450a of the first toothless gear 450 in the cylinder coupling mechanism 45) is meshed with the first rack tooth portion 451a of the first rack bar 451, the second cam receiving portion 472B of the cam member 472 is positioned on the + side in the Y direction with respect to the second convex portion 471.

In this state (the state shown by the two-dot chain line in fig. 15B), the second cam receiving portion 472B and the second convex portion 471 face each other with a slight gap in the Y direction. Thereby, even if an external force on the Y direction + side is applied to one of the second rack bars 461a (arrow F in fig. 15B)_b) Even in the case of (3), the movement of one second rack lever 461a to the + side in the Y direction can be prevented.

Specifically, if an external force F on the + side in the Y direction is applied to one of the second rack bars 461a_bThen, the one second rack lever 461a moves to the + side in the Y direction from the position indicated by the two-dot chain line in fig. 15B to the position indicated by the solid line. In this state, the second convex portion 471 abuts against the second cam receiving portion 472b, and the one second rack lever 461a is prevented from moving to the + side in the Y direction.

< action of Circuit >

Next, the operation of the circuit 6 will be described. The circuit 6 can obtain any one of the non-energized state, the first driving state, the second driving state, and the braking state described above under the control of the control unit 44b (see fig. 1).

< first drive State >

Specifically, when the cylinder coupling mechanism 45 (also referred to as a "first coupling mechanism") is shifted from the expanded state to the contracted state (hereinafter also referred to as a "drawing operation of the cylinder coupling mechanism 45"), the circuit 6 enters the first driving state (see fig. 16B). In other words, the controller 44b switches the circuit 6 to the first driving state during the drawing operation of the cylinder connecting mechanism 45.

< second drive State >

When the arm coupling mechanism 46 (also referred to as "second coupling mechanism") is shifted from the expanded state to the contracted state (hereinafter also referred to as "extraction operation of the arm coupling mechanism 46"), the circuit 6 enters the second driving state (see fig. 16C). In other words, the control unit 44b switches the circuit 6 to the second driving state during the withdrawing operation of the arm connecting mechanism 46.

< braking State 1 >

The circuit 6 is in the braking state when the arm coupling mechanism 46 shifts from the contracted state (see fig. 19C) to the expanded state (see fig. 19A) (hereinafter, also referred to as "insertion operation of the arm coupling mechanism 46"). In other words, the control unit 44b switches the circuit 6 to the braking state during the insertion operation of the arm coupling mechanism 46.

When the arm coupling mechanism 46 is shifted from the contracted state to the expanded state in the braking state of the electric circuit 6, the electric motor 41 idles by the biasing force of the second biasing mechanism 463. The electric motor 41 generates power based on this idling. The electric current generated by the electric motor 41 is returned to the electric motor 41 through the closed circuit 66. Then, a lorentz force is generated in the electric motor 41 based on the current returned to the electric motor 41. The lorentz force acts as a braking force on the electric motor 41. Further, the above current is converted into thermal energy by a resistor (not shown) provided in the closed circuit 66. The braking force as described above is adjusted according to the resistance value of the closed circuit 66. As an example, the resistance value may be manually adjusted by an operator.

The braking force described above helps prevent the overrun of the second missing-tooth gear 460 (see fig. 19A to 19C) during the insertion operation of the arm coupling mechanism 46. The reason for this will be described with reference to fig. 19A to 19C.

First, in the insertion operation of the arm coupling mechanism 46, the second toothless gear 460 is biased by the second biasing mechanism 463 toward the arrow F in fig. 19C₂Is rotated. At this time, the electric motor 41 is in a non-energized state. The brake mechanism 42 is in a released state.

The electric motor 41 idles based on the rotation of the second missing gear 460. The electric motor 41 generates power based on this idling. The electric current generated by the electric motor 41 is returned to the electric motor 41 through the closed circuit 66. Then, a lorentz force is generated in the electric motor 41 based on the current returned to the electric motor 41. The lorentz force acts as a braking force on the electric motor 41. Further, the above current is converted into thermal energy by a resistor (not shown) provided in the closed circuit 66. Such a braking force acts on the second missing-tooth gear 460 as resistance to the rotation of the second missing-tooth gear 460. Then, the second toothless gear 460 stops at the reference position shown in fig. 19A.

As described above, if the second missing-tooth gear 460 stops at the reference position, the force in the pull-out operation direction does not act on the cylinder coupling mechanism 45. The force in the withdrawal operation direction means a force for causing the cylinder coupling mechanism 45 to shift from the state shown in fig. 18A to the state shown in fig. 18B. Further, if the second toothless gear 460 is stopped, the idling of the electric motor 41 is also stopped, and therefore the above-described braking force is not generated. Therefore, the braking force described above does not act on the second missing gear 460 in the stopped state.

The braking force does not have a force to stop the cylinder connecting pins 454a and 454b and the arm connecting pin 144a at positions other than the first end and the second end of the stroke of the cylinder connecting pins 454a and 454b and the arm connecting pin 144 a. The first end of the stroke corresponds to a position (position shown in fig. 18A and 19A) corresponding to the inserted state of the cylinder coupling pins 454a and 454b and the arm coupling pin 144 a. The second end of the stroke corresponds to a position (position shown in fig. 18C and 19C) corresponding to the pulled-out state of the cylinder connecting pins 454a and 454b and the arm connecting pin 144 a. That is, the cylinder coupling pins 454a and 454b and the arm coupling pin 144a do not stop during operation (i.e., at positions other than both ends of the stroke). If the cylinder link pins 454a and 454b and the arm link pin 144a are stopped during the operation, a malfunction may be caused. According to the present embodiment, since the cylinder connecting pins 454a and 454b and the arm connecting pin 144a can be suppressed from stopping at such a position that may cause a failure, the cylinder connecting mechanism 45, the arm connecting mechanism 46, and thus the traveling crane 1 can be suppressed from failing.

< braking State 2 >

Further, the circuit 6 enters the braking state when the cylinder coupling mechanism 45 shifts from the contracted state (see fig. 18C) to the expanded state (see fig. 18A) (hereinafter, also referred to as "insertion operation of the cylinder coupling mechanism 45"). In other words, the control unit 44b switches the circuit 6 to the braking state during the insertion operation of the cylinder coupling mechanism 45.

When the cylinder coupling mechanism 45 is shifted from the contracted state to the expanded state in the braking state of the electric circuit 6, the electric motor 41 idles by the biasing force of the first biasing mechanism 455. The electric motor 41 generates power based on this idling. The electric current generated by the electric motor 41 is returned to the electric motor 41 through the closed circuit 66. Then, a lorentz force is generated in the electric motor 41 based on the current returned to the electric motor 41. The lorentz force acts as a braking force on the electric motor 41.

The braking force described above contributes to preventing the overrun of the first missing-tooth gear 450 during the insertion operation of the cylinder coupling mechanism 45. The reason for this is the same as in the case of the arm coupling mechanism 46 described above, and therefore, the description thereof is omitted.

< action of actuator >

The expansion and contraction operation of the telescopic arm 14 and the operation of the actuator 2 during the expansion and contraction operation will be described below with reference to fig. 2A to 2E and fig. 17.

Fig. 17 is a timing chart of the extending operation of the distal end arm element 141 of the telescopic arm 14.

The actuator 2 according to the present embodiment alternately performs the operation of withdrawing the cylinder connecting pins 454a and 454b and the operation of withdrawing the arm connecting pin 144a by switching the rotational direction of 1 electric motor 41 and the switching gears (i.e., the first and second missing-teeth gears 450 and 460) that distribute the driving force of the electric motor 41 to the cylinder connecting mechanism 45 and the arm connecting mechanism 46.

Hereinafter, only the extending operation of the distal end arm element 141 of the telescopic arm 14 will be described. The contraction operation of the front-end arm element 141 is in reverse order to the following expansion and contraction operation.

In the following description, the state transition between the expanded state and the contracted state of the cylinder coupling mechanism 45 and the arm coupling mechanism 46 is as described above. Therefore, detailed description of the state transition of the cylinder coupling mechanism 45 and the arm coupling mechanism 46 will be omitted.

The ON/OFF switching of the electric motor 41 and the ON/OFF switching of the brake mechanism 42 are controlled by the control unit based ON the output of the position information detection device 44.

Fig. 2A shows the contracted state of the telescopic arm 14. In this state, the front arm element 141 is coupled to the intermediate arm element 142 by the arm coupling pin 144 a. Therefore, the front arm element 141 cannot move in the longitudinal direction (the left-right direction in fig. 2A to 2E) with respect to the intermediate arm element 142.

In fig. 2A, the distal end portions of the cylinder connecting pins 454a and 454b are engaged with the pair of cylinder pin receiving portions 141a of the distal end arm element 141. That is, the front end arm element 141 and the cylinder member 32 are connected to each other.

In the state of fig. 2A, the states of the respective members are as follows (see T0 to T1 in fig. 17).

The braking mechanism 42: OFF (OFF)

Electric motor 41: OFF (OFF)

Cylinder connection mechanism 45: expanded state

Arm connecting mechanism 46: expanded state

Cylinder coupling pins 454a, 454 b: inserted state

Arm link pin 144 a: inserted state

Next, in the state shown in fig. 2A, the electric motor 41 is rotated in the normal direction (rotated in the first direction which is the clockwise direction when viewed from the distal end side of the output shaft), and the arm coupling mechanism 46 of the actuator 2 moves the pair of arm coupling pins 144a in the direction of being disengaged from the pair of first arm pin receiving portions 142b of the intermediate arm element 142. At this time, the arm coupling mechanism 46 shifts from the expanded state to the contracted state.

The states of the respective members when fig. 2A shifts to the state of fig. 2B are as follows (see T1 to T2 in fig. 17).

The braking mechanism 42: OFF (OFF)

Electric motor 41: ON (Start)

Cylinder connection mechanism 45: expanded state

Arm connecting mechanism 46: expanded state → contracted state

Cylinder coupling pins 454a, 454 b: inserted state

Arm link pin 144 a: inserted state → extracted state

As the state transitions, the engagement between the pair of arm connecting pins 144a and the pair of first arm pin receiving portions 142B of the intermediate arm element 142 is released (see fig. 2B). After that, the brake mechanism 42 is turned ON (activated), and the electric motor 41 is turned OFF (deactivated).

The control unit appropriately controls the timing of turning OFF (turning OFF) the electric motor 41 and the timing of turning ON (turning ON) the brake mechanism 42. For example, although not shown, the electric motor 41 is turned OFF (turned OFF) after the brake mechanism 42 is turned ON (turned ON).

In the state of fig. 2B, the states of the respective members are as follows (see T2 in fig. 17).

The braking mechanism 42: ON (Start)

Electric motor 41: OFF (OFF)

Cylinder connection mechanism 45: expanded state

Arm connecting mechanism 46: reduced state

Cylinder coupling pins 454a, 454 b: inserted state

Arm link pin 144 a: extracted state

Next, in the state shown in fig. 2B, pressure oil is supplied to the extension-side hydraulic chamber in the telescopic cylinder 3 of the actuator 2. Then, the cylinder member 32 moves in the extending direction (left side in fig. 2A to 2E).

The distal end arm element 141 moves in the extending direction together with the movement of the cylinder member 32 as described above (see fig. 2C). At this time, the states of the respective parts are: the state of T2 of fig. 17 is maintained to T3.

Next, in the state shown in fig. 2C, the brake mechanism 42 is released. Then, the arm connecting mechanism 46 moves the pair of arm connecting pins 144a in a direction to engage with the pair of second arm pin receiving portions 142c of the intermediate arm element 142, based on the biasing force of the second biasing mechanism 463. At this time, the arm coupling mechanism 46 is shifted from the contracted state to the expanded state (i.e., automatically restored). That is, the arm connecting mechanism 46 is inserted.

In the insertion operation of the arm connecting mechanism 46, the circuit 6 described above is in a braking state (see fig. 16D). During the insertion operation of the arm coupling mechanism 46, the electric circuit 6 is switched to the closed circuit 66, so that the braking force as described above acts on the electric motor 41. The pair of arm connecting pins 144a are stopped at the reference positions of the arm connecting pins 144a shown in fig. 19A based on the braking force.

The states of the respective members when fig. 2C shifts to the state of fig. 2D are as follows (see T3 to T4 in fig. 17).

The braking mechanism 42: OFF (OFF)

Electric motor 41: OFF (OFF)

Cylinder connection mechanism 45: expanded state

Arm connecting mechanism 46: contracted state → expanded state

Cylinder coupling pins 454a, 454 b: inserted state

Arm link pin 144 a: extracted state → inserted state

Then, as shown in fig. 2D, the pair of arm connecting pins 144a engage with the pair of second arm pin receiving portions 142c of the intermediate arm element 142.

The state of each member in the state shown in fig. 2D is as follows (see T4 in fig. 17).

The braking mechanism 42: OFF (OFF)

Electric motor 41: OFF (OFF)

Cylinder connection mechanism 45: expanded state

Arm connecting mechanism 46: expanded state

Cylinder coupling pins 454a, 454 b: inserted state

Arm link pin 144 a: inserted state

Further, in the state shown in fig. 2D, the electric motor 41 is rotated in the reverse direction (rotated in the second direction which is the counterclockwise direction when viewed from the distal end side of the output shaft), and the pair of cylinder connecting pins 454a and 454b are moved in the direction of being disengaged from the pair of cylinder pin receiving portions 141a of the distal end arm element 141 by the cylinder connecting mechanism 45. At this time, the cylinder coupling mechanism 45 is shifted from the expanded state to the contracted state.

The states of the respective members when fig. 2D shifts to the state of fig. 2E are as follows (see T4 to T5 in fig. 17).

The braking mechanism 42: OFF (OFF)

Electric motor 41: ON (Start)

Cylinder connection mechanism 45: expanded state → contracted state

Arm connecting mechanism 46: expanded state

Cylinder coupling pins 454a, 454 b: inserted state → extracted state

Arm link pin 144 a: inserted state

Then, as shown in fig. 2E, the engagement between the distal end portions of the pair of cylinder coupling pins 454a and 454b and the pair of cylinder pin receiving portions 141a of the distal end arm element 141 is released. After that, the brake mechanism 42 is turned ON (activated), and the electric motor 41 is turned OFF (deactivated).

The state of each member in the state shown in fig. 2E is as follows (see T5 in fig. 17).

The braking mechanism 42: ON (Start)

Electric motor 41: OFF (OFF)

Cylinder connection mechanism 45: reduced state

Arm connecting mechanism 46: expanded state

Cylinder coupling pins 454a, 454 b: extracted state

Arm link pin 144 a: inserted state

Thereafter, although not shown, if pressure oil is supplied to the contracting-side hydraulic chamber in the telescopic cylinder 3 of the actuator 2, the cylinder member 32 moves in the contracting direction (rightward in fig. 2A to 2E). At this time, the front end arm element 141 and the cylinder member 32 are in a non-coupled state, and therefore the cylinder member 32 alone moves in the contraction direction. When the intermediate arm element 142 is extended, the operations of fig. 2A to 2E are performed with respect to the intermediate arm element 142.

< action/Effect of the present embodiment >

In the case of the mobile crane 1 according to the present embodiment having the above-described configuration, the electric circuit 6 is in the braking state during the insertion operation of the arm connecting mechanism 46 (see fig. 16D). Then, by switching the circuit 6 to the closed circuit 66, the braking force as described above is generated in the electric motor 41. If the braking force acts on the electric motor 41, the pair of arm connecting pins 144a stop at the reference positions shown in fig. 19A. In this way, since the overrun of the second toothless gear 460 (see fig. 19A) of the arm coupling mechanism 46 is prevented, the force in the direction of the state transition from the expanded state to the contracted state does not act on the cylinder coupling mechanism 45.

In addition, the circuit 6 described above is also in the braking state during the insertion operation of the cylinder connecting mechanism 45 (see fig. 16D). Then, by switching the circuit 6 to the closed circuit 66, the above-described braking force is generated in the electric motor 41. If the braking force acts on the electric motor 41, the pair of cylinder coupling pins 454a and 454b are stopped at the reference positions shown in fig. 18A based on the braking force. In this way, since overrun of the first toothless gear 450 (see fig. 18A) of the cylinder coupling mechanism 45 is prevented, a force in a direction in which the state is shifted from the expanded state to the contracted state does not act on the arm coupling mechanism 46.

In the case of the traveling crane 1 according to the present embodiment, since the cylinder connection mechanism 45 and the arm connection mechanism 46 are electrically operated, it is not necessary to provide a hydraulic circuit as in the conventional structure in the internal space of the telescopic arm 14. Therefore, the space originally used in the hydraulic circuit can be effectively utilized, and the degree of freedom in design in the internal space of the telescopic arm 14 can be improved.

In the case of the present embodiment, the position detection of the cylinder connecting pins 454a and 454b and the arm connecting pins 144a and 144b is performed by the position information detecting device 44 described above. Therefore, in the present embodiment, a proximity sensor for detecting the positions of the cylinder connecting pins 454a and 454b and the arm connecting pins 144a and 144b is not required. Such proximity sensors are provided at positions capable of detecting the insertion state and the extraction state of the cylinder connecting pins 454a and 454b and the arm connecting pins 144a and 144b, respectively, for example. In this case, the number of proximity sensors needs to be at least the same as the cylinder connecting pins 454a and 454b and the second rack bars 461a and 461 b. On the other hand, in the case of the present embodiment, the positions of the cylinder connecting pins 454a and 454b and the arm connecting pins 144a and 144b can be detected by the position information detecting device 44 (i.e., one detector) including 1 detecting unit 44a as described above.

The disclosures of the specification, drawings and abstract of the specification contained in japanese application No. 2019-72143 filed on 4/2019 are incorporated herein by reference in their entirety.

< appendix >)

The work machine according to the present invention includes, as a basic configuration:

an actuator configured to extend and retract the telescopic arm;

an electric drive source provided in the actuator and driven by power supplied from a power supply;

the operation unit operates based on the power of the electric drive source.

In addition, in the case of implementing the present invention, the working machine may further include:

a circuit capable of switching between a driving state in which power supply from the power supply to the electric drive source is permitted to drive the electric drive source and a braking state in which power supply from the power supply to the electric drive source is stopped and braking force applied to the electric drive source is generated; and

and a control unit for controlling switching between the drive state and the brake state.

In the case of implementing the present invention, the arm may further include a first arm element and a second arm element that are overlapped in an extendable and retractable manner.

In addition, when the present invention is implemented, the operation unit may further include:

a first coupling mechanism that operates based on power of the electric drive source and switches between a coupled state and an uncoupled state between the first arm element and the actuator;

the second coupling mechanism operates on the basis of power of the electric drive source, and switches between a coupled state and an uncoupled state between the first arm element and the second arm element.

The work machine according to the reference example of the present invention may have any configuration selected from the configurations of the work machines described in the above embodiments, in addition to the basic configuration described above. The working machine according to the reference example is not limited to the crane, and may be various working machines including a telescopic arm.

Industrial applicability

The crane according to the present invention is not limited to a crane having a complicated terrain, and may be various mobile cranes such as an all terrain crane, a truck crane, and a loading truck crane (also referred to as a "cargo crane"). The crane according to the present invention is not limited to a mobile crane, and may be another crane having a telescopic arm.

Description of the reference numerals

1 Mobile crane

10 traveling body

101 wheel

11 outrigger

12 revolving platform

14 Telescopic arm

141 front end arm element

141a cylinder pin receiving part

141b arm pin receiving part

142 middle arm element

142a cylinder pin receiving part

142b first arm pin receiving part

142c second arm pin receiving part

142d third arm pin receiving part

143 base end arm element

144a, 144b arm connecting pin

144c pin side receiving part

15 heave oil cylinder

16 steel cable

17 hook

2 actuator

3 Telescopic oil cylinder

31 Bar Member

32 oil cylinder component

4-pin moving module

40 outer casing

400 first housing element

400a, 400b through hole

401 second housing element

401a, 401b through hole

41 electric motor

410 manual operation part

42 brake mechanism

43 transfer mechanism

431 speed reducer

431a speed reducer box

432 transmission shaft

44 position information detecting device

44b control part

45 oil cylinder connecting mechanism

450 first gear with missing teeth

450a first tooth

450b positioning tooth

451 first rack bar

451a first rack tooth part

451b second rack tooth part

451c third rack tooth part

451d first end face

452 first gear mechanism

452a, 452b, 452c Gear elements

453 second gear mechanism

453a, 453b Gear element

454a, 454b cylinder connecting pin

454c, 454d Pin-side Rack tooth

455 first force applying mechanism

455a, 455b coil spring

46 arm connecting mechanism

460 second gear with missing teeth

460a second tooth part

460b positioning tooth

461a, 461b second rack bar

461c driving rack tooth part

461d first end face

Rack tooth part for 461e and 461f synchronization

461g, 461h engaging claw

462 synchronous gear

463 second force application mechanism

463a, 463b coil springs

47 locking mechanism

470 first convex part

471 second projection

472 cam member

472a first cam receiving part

472b second cam receiving part

48 limiting surface

49 integral type gear with missing teeth

49a tooth

500A position information detection device

501A first detection device

50A first detected part

Third small diameter portions 50f3 and 50f5

51A first sensor part

502A second detection device

52A second detection target portion

6 circuit

61 Power supply device

62 first switch

63 second switch

64 third switch

65 fourth switch

66 closed circuit

6L1 first line

6L2 second line

6L3 third line