阅读说明：本技术 压桩装置及压桩方法 (Pile pressing device and pile pressing method ) 是由 大野正明 小野胜彦 森冈芳弘 野中建吾 于 2020-02-19 设计创作，主要内容包括：本发明提供一种即使为了向驱动构件提供驱动力而电动机与油压装置混合存在,也能实现高效施工的压桩装置及压桩方法。压桩装置(1)为了一边旋转桩(4)一边将其压入地面,而具备夹持桩(4)并使其旋转的夹头(5)。压桩装置(1)由相当于本发明的电动机的电动电机(6)提供用于使夹头(5)旋转的驱动力。夹头(5)通过以油压工作的油压装置即升降缸(7)而上下移动。综合控制盘(50)控制电动电机(6)与升降缸(7)联动。(The invention provides a pile driving device and a pile driving method which can realize high-efficiency construction even if a motor and a hydraulic device are mixed for providing driving force for a driving component. The pile driving device (1) is provided with a chuck (5) for clamping and rotating the pile (4) in order to press the pile (4) into the ground while rotating the pile. The pile driving device (1) is provided with a driving force for rotating the chuck (5) by an electric motor (6) corresponding to the motor of the invention. The chuck (5) is moved up and down by a lift cylinder (7) which is a hydraulic device operated by oil pressure. The comprehensive control panel (50) controls the electric motor (6) to be linked with the lifting cylinder (7).)

1. A pile driving apparatus for driving a pile into the ground while rotating the pile, comprising:

a rotation mechanism for gripping the pile and rotating it;

a motor that acts on the rotation mechanism and supplies a driving force for the rotation to the rotation mechanism;

a hydraulic device serving as a lifting mechanism for vertically moving the rotating mechanism; and

and a control means for controlling the electric motor by interlocking the electric motor with the hydraulic device.

2. Pile-driving device according to claim 1,

the control mechanism controls the vertical movement of the rotation mechanism by the lifting mechanism based on a rotation output of the motor when the pile held by the rotation mechanism is pressed in.

3. Pile-driving device according to claim 2,

the rotational output is calculated based on an inverter command to the motor.

4. Pile-driving device according to claim 2 or 3,

the control means stops the lowering operation of the rotating means by the lifting means when the rotation output of the motor reaches a predetermined value.

5. A pile-driving device according to any one of claims 2 to 4,

the control mechanism controls the rotational output of the motor in accordance with a load state of the motor.

6. Pile driving device according to one of claims 1 to 5,

which includes a cooling mechanism for cooling the motor.

7. Pile-driving device according to claim 6,

the cooling mechanism is a fan directly connected to a rotating shaft of the motor.

8. Pile-driving device according to claim 7,

the cooling mechanism is a fan provided independently of the rotating shaft of the motor,

the control mechanism controls the cooling amount of the fan in accordance with a rotation output or a load state of the motor.

9. Pile-driving device according to claim 6,

the cooling mechanism is a cooling pipe through which a cooling liquid flows,

the cooling liquid cools the motor, and then cools a speed reducer coupled to a rotating shaft of the motor.

10. Pile-driving device according to claim 9,

the control means controls the cooling amount of the cooling liquid in accordance with a rotation output or a load state of the motor.

11. Pile-driving device according to claim 9 or 10,

which comprises a mast supporting the lifting mechanism in a manner of relatively moving in the up-down direction,

a contraction member for contracting a cooling pipe through which the coolant flows and a hydraulic pipe that supplies the hydraulic oil to the hydraulic device is attached to the mast.

12. Pile-driving device according to any one of claims 9 to 11,

the coolant also serves as water that is ejected from the tip of the pile when the pile is pressed into the ground.

13. A pile-driving device according to any one of claims 1 to 12,

the hydraulic pressure generating device for supplying the hydraulic oil to the hydraulic device is driven by a motor.

14. A pile driving device in which a part of a plurality of driving members are driven by an electric motor and the other driving members are driven by a hydraulic device, wherein,

the pile pressing device comprises a control mechanism,

the control means controls the electric motor and the hydraulic device in accordance with a driving state of the driving member.

15. A pile driving method using a pile driving apparatus including a rotation mechanism for holding and rotating a pile, an elevating mechanism for elevating and lowering the rotation mechanism, a motor for applying a driving force for the rotation to the rotation mechanism by acting on the rotation mechanism, and an oil pressure device for moving the rotation mechanism up and down as an elevating mechanism,

the control is performed by interlocking the electric motor with the hydraulic device when the pile is pressed into the ground while being rotated.

Technical Field

The invention relates to a pile pressing device and a pile pressing method.

Background

A pile driving device that rotates a pile while pressing the pile into the ground uses a hydraulic device, such as a hydraulic motor or a lift cylinder, or a hydraulic pressure generating device (hydraulic pump) that supplies hydraulic oil to the hydraulic driving device, to rotationally drive and vertically move a chuck that holds the pile.

Fig. 9 is a conventional configuration diagram of a pile driving system 100 in which a chuck 101 is rotationally driven at high output by a hydraulic motor.

In the conventional pile driving system 100, in order to rotationally drive the chuck 101 of the pile driving device 102 at a high output, it is necessary to increase the number of hydraulic motors that supply driving force to the chuck 101. Therefore, as the number of hydraulic motors increases, the number of power units 103 (hydraulic units) for supplying the hydraulic fluid to the hydraulic motors also increases. In addition, the power unit 103A of fig. 9 is an added power unit 103.

If the number of power units 103 is increased, it is difficult to dispose the increased number of power units 103 on the completed pile, and workability may be deteriorated. Further, when the power unit 103 is disposed at a place distant from the pile driving device 102, the influence of the drop in the working oil pressure due to the pressure loss cannot be ignored.

Therefore, patent document 1 discloses driving the chuck by an electric motor. When an electric motor is used instead of the hydraulic motor for supplying the driving force to the chuck, it is easy to increase the output and it is not necessary to increase the power unit 102 as described above. In addition, the motorization has an advantage that problems such as pressure loss of the working oil and leakage of the working oil do not occur.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 8-35226.

Disclosure of Invention

(problems to be solved by the invention)

As shown in patent document 1, when a part of a device for driving a driving member such as a chuck is replaced with a motor from a hydraulic device, the motor and the hydraulic device are mixed in a pile driving device. Even in such a pile driving device in which the motor and the hydraulic device are mixed, it is required to perform construction with the same efficiency as that of a conventional pile driving device in which the motor and the hydraulic device are not mixed.

Accordingly, an object of the present invention is to provide a pile driving device and a pile driving method which can perform efficient construction even when a motor and a hydraulic device are mixed to provide a driving force to a driving member.

(means for solving the problems)

The pile driving apparatus of the present invention is for driving a pile into the ground while rotating the pile, and includes: a rotation mechanism that grips the pile and rotates the pile; a motor that acts on the rotation mechanism to provide the rotation mechanism with a driving force for the rotation; an oil pressure device as a lifting mechanism for moving the rotating mechanism up and down; and a control mechanism that performs control by interlocking the electric motor with the hydraulic device.

According to this configuration, the rotation mechanism that holds and rotates the pile is driven by the motor, and the lifting mechanism that moves the rotation mechanism up and down is a hydraulic device. In addition, since the present configuration realizes optimal control of the hydraulic device and the electric motor by controlling the electric motor and the hydraulic device in a linked manner, efficient construction is possible even if the electric motor and the hydraulic device are present in a mixed manner in order to provide driving force to the driving member.

In the pile driving device according to the present invention, the control means may control the vertical movement of the rotation means by the elevating means based on a rotation output of the motor when the pile held by the rotation means is driven in. According to this configuration, the rotation output of the motor reflects information on the ground surface (ground surface information) of the driven pile, and the vertical movement of the lifting mechanism relative to the rotation mechanism can be controlled based on the rotation output of the motor, thereby achieving efficient construction.

The pile driving device according to the present invention may be configured to calculate the rotation output based on an inverter command to the motor. According to this configuration, the rotation output of the motor, that is, the ground information can be easily grasped.

In the pile driving device according to the present invention, the control means may stop the lowering operation of the rotation mechanism by the elevating means when the rotation output of the motor reaches a predetermined value. According to the structure, the front end of the pile can be prevented from being damaged due to excessive ground resistance.

In the pile driving device according to the present invention, the control means may control the rotational output of the motor in accordance with a load state of the motor. According to the present configuration, efficient construction can be achieved by increasing the rotation torque, for example, in accordance with the load state of the motor.

The pile driving device of the present invention may also include a cooling mechanism for cooling the motor. According to the structure, the motor can be prevented from overheating.

In the pile driving device according to the present invention, the cooling mechanism may be a fan directly connected to a rotating shaft of the motor. According to the present configuration, the motor can be cooled by a simple configuration.

In the pile driving device according to the present invention, the cooling mechanism may be a fan provided independently of a rotation shaft of the motor, and the control mechanism may control a cooling amount of the fan in accordance with a rotation output or a load state of the motor. According to the structure, the motor can be effectively cooled.

In the pile driving device according to the present invention, the cooling mechanism may be a cooling pipe through which a coolant flows, and the coolant cools the reducer connected to the rotating shaft of the motor after cooling the motor. According to the present configuration, the speed reducer is more resistant to temperature rise than the motor, so the motor and the speed reducer can be cooled efficiently.

In the pile driving device according to the present invention, the control means may control the cooling amount of the coolant in accordance with a rotation output or a load state of the motor. According to the structure, the motor can be effectively cooled.

The pile driving device according to the present invention may include a mast that supports the lifting mechanism so as to be relatively movable in the vertical direction, and the mast may be provided with a contracting member that contracts the cooling pipe through which the coolant flows and the hydraulic pipe through which the hydraulic oil is supplied to the hydraulic device. Depending on the ground state, the configuration may be switched from the configuration in which the rotating mechanism is driven by the motor to the configuration in which the rotating mechanism is driven by the hydraulic device. According to this configuration, the cooling pipe and the hydraulic pipe are bundled by the bundling member, and the replacement operation can be performed efficiently.

In the pile driving device according to the present invention, the coolant may also serve as water to be ejected from the pile tip when the pile is driven into the ground. According to this configuration, the coolant can be effectively used.

The pile pressing device according to the present invention may be a hydraulic pressure generating device that supplies the hydraulic oil to the hydraulic device by driving the hydraulic device with a motor. In a conventional pile driving device, an internal combustion engine is used as a driving device for a hydraulic pressure generating device. The present configuration uses an electric motor driven by a commercial power supply instead of an internal combustion engine, thereby reducing the environmental load.

The pile driving device according to the present invention may be configured such that a part of the plurality of driving members is driven by the electric motor, and the other driving members are driven by the hydraulic device, and the pile driving device may further include a control means for controlling the electric motor and the hydraulic device in accordance with a driving state of the driving members. As an example, the driving means is a hydraulic pump that supplies hydraulic oil to a hydraulic cylinder, and the electric motor is an electric motor that drives the hydraulic pump. The motor is an electric motor that drives the spin chuck as a driving member. When the driving member is a hydraulic cylinder, the hydraulic device for driving is a hydraulic pump.

According to the present configuration, even if the electric motor and the hydraulic device are mixed in order to provide the driving force to the driving member, efficient construction can be achieved.

The pile driving method according to the present invention may be a pile driving method using a pile driving apparatus including a rotation mechanism for rotating a pile while sandwiching the pile, an elevating mechanism for elevating and lowering the rotation mechanism, a motor for applying the rotational driving force to the rotation mechanism by acting on the rotation mechanism, and a hydraulic device for vertically moving the rotation mechanism as the elevating mechanism, wherein the control is performed by interlocking the motor with the hydraulic device when the pile is pressed into the ground while rotating the pile. According to the present configuration, even if the electric motor and the hydraulic device are mixed in order to provide the driving force to the driving member, efficient construction can be achieved.

Effects of the invention

According to the present invention, even if the motor and the hydraulic device are mixed in order to provide the driving force to the driving member, efficient construction can be realized.

Drawings

Fig. 1 is an external view of a pile driving system according to the present embodiment.

Fig. 2 is a structural view of the pile driving device according to the present embodiment as viewed from above.

Fig. 3 is a schematic diagram showing a cooling pipe for cooling the electric motor according to the present embodiment.

Fig. 4 is a schematic diagram showing a control system, an electric power system, and a hydraulic power system of the pile driving system according to the present embodiment.

Fig. 5 is a block diagram showing a control system of the pile driving system according to the present embodiment.

Fig. 6 is a graph showing rotation characteristics of the hydraulic motor and the electric motor, where 6(a) shows the rotation characteristics of the hydraulic motor, and 6(b) shows the rotation characteristics of the electric motor.

Fig. 7 is a configuration diagram showing replacement of a collet of the pile driver according to the present embodiment.

Fig. 8 is a schematic view showing air cooling of an electric motor according to a modification.

Fig. 9 is an external view of a conventional pile-driving system.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiments described below are merely examples of the present invention, and the present invention is not limited to the specific configurations described below. In carrying out the present invention, the specific configuration according to the embodiment can be adopted as appropriate. In addition, the pile pressing device of the present embodiment uses the completed pile (completed pile) as a reaction force, and automatically moves the head of the completed pile to sequentially press the pile. By this construction method, it is possible to perform press-fitting construction into an underground structure such as a hard ground or a concrete structure, and it is possible to shorten the construction period and realize environment-friendly construction without requiring a temporary pier.

Fig. 1 is a side view showing the overall configuration of a pile driving system 3 including a pile driving device 1 and a power unit 2 according to the present embodiment.

The pile driving device 1 of the present embodiment includes a chuck 5 for holding the pile 4 and rotating the pile 4 to press the pile 4 into the ground while rotating the pile 5. The chuck 5 corresponds to the rotating mechanism of the present invention. The chuck 5 of the present embodiment is supplied with a rotational driving force by an electric motor 6 corresponding to the motor of the present invention. One example of the electric motor 6 is a motor that controls at least one of the frequency, voltage, and current of power supply via inverter control, thereby controlling the rotational output (rotational torque, rotational speed).

Further, the chuck 5 is moved up and down by the lift cylinder 7. The lift cylinder 7 corresponds to the lift mechanism of the present invention, and is a hydraulic device (hydraulic drive device) that operates by hydraulic pressure.

The power unit 2 of the present embodiment includes: a control unit 8 for controlling the electric motor 6; and an electric hydraulic unit 9 for supplying hydraulic oil to a hydraulic device such as the lift cylinder 7. The control unit 8 includes an inverter device 10, and the inverter device 10 controls the rotation torque of the electric motor 6 and the like. The electric hydraulic unit 9 includes a hydraulic pump 11 (hydraulic pressure generating device), the hydraulic pump 11 is used to supply hydraulic oil to a hydraulic device such as the lift cylinder 7, and the hydraulic pump 11 is driven by an electric motor 12. The hydraulic oil is stored in a hydraulic oil tank 13 provided in the electric hydraulic unit 9.

Both of the electric motors 6 and 12 of the pile driving system 3 are supplied with power from a commercial power source through a power cable.

Here, in the conventional pile driving system 3, an internal combustion engine (so-called engine) is used as a driving device of the hydraulic pump 11, but the internal combustion engine generates exhaust gas and places a burden on the environment. On the other hand, in the power unit 2 of the present embodiment, the electric motor 12 as an electric motor is used instead of the internal combustion engine as described above, and therefore, no exhaust gas is generated, and the environmental load can be reduced.

Further, in the power unit 2 of the present embodiment, the chuck 5 is driven by the electric motor 6, and the capacity of the hydraulic oil tank 13 for storing the hydraulic oil is smaller than that in the case where the chuck 5 is driven by the hydraulic motor. Further, the electric motor 12 is smaller and lighter than the internal combustion engine. Therefore, the power unit 2 of the present embodiment is smaller than the conventional one.

As will be described in detail later, the rotational output of the chuck 5 can be highly electrically output by using the electric motor 6 as a driving device of the chuck 5. That is, when the chuck 5 is driven by the hydraulic motor, in order to increase the output of the chuck 5, it is necessary to increase the number of the hydraulic motors and the number of the power units 2 that supply the hydraulic oil to the hydraulic motors at the same time (see fig. 9). On the other hand, by using the electric motor 6 as the driving device of the collet 5 as in the pile driving system 3 of the present embodiment, the rotational output of the collet 5 can be increased without increasing the number of power units 2.

In this manner, the pile driving device 1 (pile driving system 3) of the present embodiment drives a part of the plurality of driving members by the electric motor, and drives the other driving members by the hydraulic device. That is, in the pile driver 1 of the present embodiment, when the driving member is the chuck 5, the motor is the electric motor 6 that drives the chuck 5 to rotate. When the other driving means is the lift cylinder 7, the hydraulic device for driving is the hydraulic pump 11. In the pile driving system 3 of the present embodiment, when the driving means is the hydraulic pump 11 provided in the power unit 2, the electric motor is the electric motor 12 for driving the hydraulic pump 11.

Next, the structure of the pile driver 1 according to the present embodiment will be described in detail with reference to fig. 2. Fig. 2 is a top view of the pile driver 1 shown in fig. 1, viewed from above.

As described above, the pile driver 1 obtains a reaction force from the completed pile 4B (reaction force pile) and pushes the push-in pile 4A made of a steel pipe having a predetermined length into a predetermined position (see fig. 1). The pile driver 1 is used, for example, in a revetment or a retaining wall work in which a plurality of piles 4, 4 are driven in a row in one direction. The driven pile 4A driven by the pile driving device 1 is suspended by a crane (not shown) movably provided near the pile driving device 1. In the following description, among the piles 4, the pile pressed in by the pile pressing device 1 is referred to as a pressed-in pile, and is denoted by reference numeral 4A, the driven pile is referred to as a completed pile, and is denoted by reference numeral 4B, and the completed pile 4B clamped by the later-described clamper 23 is referred to as a reaction force pile.

Pile driver 1 includes: a chuck 5 for detachably holding a press-in pile 4A having a circular tube shape; a mast 20 that supports the chuck 5 so as to be relatively movable in the vertical direction y; and a saddle 21 that supports the mast 20 so as to be relatively movable in the front-rear direction x 1. The pile driving apparatus 1 moves (moves by itself) in the arrangement direction on the plurality of completed piles 4B arranged by the movement of the mast 20. In addition, the power unit 2 moves together with the pile driving device 1 on the completed pile 4B.

The saddle 21 includes a saddle body 22, and a plurality of (three in the example of fig. 1) clamps 23 that depend from the saddle body 22. The clamper 23 is configured to hold and release the completed pile 4B from inside by a hydraulic cylinder, not shown, in a state inserted inside the upper end 2a of the completed pile 4B.

The mast 20 includes: a plate-shaped slide frame 24 provided on the saddle main body 22; a mast base 26 provided on the slide frame 24 via the rotating portion 25; and an upper and lower rail part 27 provided at the front end of the mast base 26. The mast base 26 is rotatable about a rotation axis centered on the vertical direction y of the rotating portion 25.

The upper and lower rail portions 27 extend in the up-down direction y. The chuck 5 is fitted to the front side of the upper and lower rail portions 27 so as to be movable up and down. The lower end of the mast 20 is provided with mast arm portions 28, 28 protruding forward from both sides in the left-right direction x 2.

The cartridge 5 includes a cartridge body 30 (refer to fig. 1), and a cartridge frame 31 that rotatably supports the cartridge body 30. As shown in fig. 2, the chuck body 30 has an insertion hole into which the press-fitting pile 4A can be inserted in the vertical direction y. The chuck frame 31 is provided with a pair of lift cylinders 7(7A, 7B), and the front ends thereof are fixed to the pair of mast arms 28 of the mast 20, respectively. The head frame 31 is fitted slidably in the vertical direction y along the upper and lower rail portions 27 by extension and contraction of the lift cylinder 7.

The pair of lift cylinders 7 are disposed such that the extension and contraction direction of the rod is directed in the vertical direction y, and the rod tip is fixed to the projecting end of the mast arm 28. Therefore, when the rod of the lift cylinder 7 contracts from the extended state, the collet frame 31 and the collet body 30 move downward via the lift cylinder 7, and the press-fitting pile 4A clamped by the collet body 30 moves in a direction in which the pile is press-fitted downward. In this manner, the lift cylinder 7 acts on the collet body 30 via the collet frame 31 to provide the collet body 30 with a driving force for pushing the press-fitting pile 4A. Further, a stroke sensor (not shown) for detecting the stroke of the press-fitting pile 4A is provided inside the chuck frame 31.

As shown in fig. 2, the collet body 30 is rotatably supported in the collet frame 31 and is a portion for gripping the driven pile 4A. The chuck body 30 includes a plurality of chuck jaws 35 therein. The chuck body 30 is rotated with respect to the chuck frame 31 while holding the press-fitting pile 4A by pressing the press-fitting pile 4A from the outer peripheral side by the chuck claws 35.

A chuck rotating gear 36 is fixed to the outer periphery of the chuck main body 30. Around the chuck rotating gear 36, a plurality of (8 in the example of fig. 2) drive gears 37A to 37H rotatably supported on the chuck frame 31 are meshed with the chuck rotating gear 36. The drive gears 37A to 37H are driven to rotate by electric motors 6A to 6H, respectively. The electric motors 6A to 6H are fixed to the chuck frame 31 above the drive gears 37A to 37H, respectively, and the drive gears 37A to 37H are also rotatably fixed to the chuck frame 31.

Hereinafter, the drive gears 37A to 37H are collectively referred to as the drive gear 37, and the electric motors 6A to 6H are collectively referred to as the electric motor 6.

In the pile driving apparatus 1 having such a configuration, the electric motor 6 rotationally drives the drive gear 37, and the chuck main body 30 rotates via the chuck rotating gear 36, whereby the driven pile 4A held by the chuck main body 30 rotates. In this manner, the electric motor 6 and the drive gear 37 act on the chuck body 30 via the chuck rotating gear 36, and provide the chuck body 30 with a rotational driving force for pushing the push-in pile 4A.

Further, the pile driving device 1 of the present embodiment includes a cooling mechanism for cooling the electric motor 6 in order to prevent the electric motor 6 from overheating. As shown in fig. 3, the cooling mechanism of the present embodiment is a cooling pipe 41, and the electric motor 6 is cooled by the coolant flowing through the cooling pipe 41 disposed around the electric motor. Further, although water (hereinafter, "cooling water") is an example of the cooling liquid according to the present embodiment, the cooling liquid is not limited thereto, and may be an antifreeze liquid or the like.

The cooling pipe 41 cools the electric motor 6 and the reduction gear 42 connected to the rotation shaft of the electric motor 6 with cooling water. As shown by arrows in fig. 3, the cooling pipe 41 of the present embodiment is disposed so that the cooling water cools the electric motor 6 and then cools the reduction gear 42. With this configuration, speed reducer 42 is more resistant to temperature rise than electric motor 6, and electric motor 6 and speed reducer 42 can be cooled efficiently.

Further, a radiator for cooling the cooling water, a cooling electric pump for feeding the cooling water, and the like are installed on site separately from the pile driving device 1, and the cooling water is fed from a large-capacity tank installed on site to the electric motor 6 and the reduction gear 42.

More specifically, the water (cooling water) in the large-capacity tank is delivered to a pipe attached to the mast 20 by a cooling electric pump, and is delivered to a manifold block (hereinafter referred to as an "upstream-side manifold block") provided at an upper portion of the chuck 5 via a delivery pipe between the mast 20 and the chuck 5. The upstream manifold block has a pressure relief function for protecting the cooling pipe 41. The upstream manifold block branches off to the cooling pipe 41 disposed in each electric motor 6, and supplies cooling water to each electric motor 6 and the reduction gear 42. The cooling water for cooling each electric motor 6 and the reduction gear 42 passes through the downstream side manifold block and returns to the large-capacity tank through the piping on the mast 20.

The cooling water in the large-capacity tank also serves as water discharged from the tip of the pile 4 when the pile 4 is pressed into the ground. This enables the pile-pressing device 1 of the present embodiment to effectively utilize the cooling water.

Next, the control of the pile driver 1 according to the present embodiment will be described in detail. Fig. 4 is a schematic diagram showing a control system, an electric power system, and a hydraulic power system of pile driving system 3 according to the present embodiment.

The pile driving device 1 comprises an integrated control panel 50 which is responsible for the control of the pile driving system 3. The integrated control panel 50 corresponds to the control mechanism of the present invention.

The integrated control panel 50 of the present embodiment is a control device that mainly controls the electric motor 6 (electric motor) and the lift cylinder 7 (hydraulic device) in an interlocking manner. Thus, the pile driving system 3 of the present embodiment realizes optimal control of the hydraulic device and the motor, and therefore, even if the motor and the hydraulic device are present in a mixed state to supply a driving force to the driving member (e.g., the chuck 5), efficient construction can be realized.

The combination control panel 50 controls the pile driver 1 based on the set values of the load and the torque set by the operator using the operation panel 51. The operation panel 51 is held by an operator, and transmits and receives information such as setting values to and from the central control panel 50 by wireless communication.

The control unit 8 of the power unit 2 is connected to the integrated control board 50 via an electric system control line 52A to input and output information. The control unit 8 is connected to the electric motor 6 via a power line 52B, and power is supplied from the control unit 8 to the electric motor 6 by inverter control.

The electric hydraulic unit 9 included in the power unit 2 is connected to the integrated control panel 50 via a hydraulic system control line 53A to input and output information. A supply line 53B is connected to the electric hydraulic unit 9 and the mast 20, and working oil is supplied from the electric hydraulic unit 9 to the mast 20.

The mast 20 is provided with a lifting oil pressure control valve 54 and a turning oil pressure control valve 55. Connection ports corresponding to the oil supply lines 53B are provided in the lifting oil pressure control valve 54 and the rotating oil pressure control valve 55. One example of the hydraulic pressure control valves 54 and 55 is a solenoid valve.

The lift oil pressure control valve 54 is opened or closed in response to a control signal of the integrated control board 50 to control the supply of the working oil from the electric oil pressure unit 9 to the lift cylinder 7. On the other hand, the rotary hydraulic control valve 55 of the present embodiment is not connected to the electric hydraulic unit 9. The rotary hydraulic control valve 55 is used when the chuck 5 is driven by the hydraulic motor, and the pile driver 1 of the present embodiment does not have the hydraulic motor since the chuck 5 is driven by the electric motor 6.

Further, the pile driving system 3 is provided with a return line for returning the working oil supplied from the electric oil pressure unit 9 to the oil pressure device of the pile driving device 1 to the electric oil pressure unit 9, and a leak-back line for returning the working oil leaked from the oil pressure device to the electric oil pressure unit 9.

Further, the pile driving device 1 is provided with a situation detection unit 56. The status detecting unit 56 detects status data other than the rotation of the chuck 5, for example, and transmits the status data to the integrated control board 50. The condition data is, for example, the hydraulic pressure of the hydraulic oil supplied to the lift cylinder 7, the mechanical posture indicating the posture of the pile driving device 1, the gripper safety state indicating the gripping state of the gripper 23 for the completed pile 4B, and the like.

A temperature sensor 57 is provided inside each electric motor 6, and temperature information detected by the temperature sensor 57 is transmitted to the integrated control board 50. The temperature of the electric motor 6 varies depending on, for example, the rotation output and the torque load factor. Further, although the resistance temperature detector is an example of the temperature sensor 57, the temperature sensor is not limited to this, and may be another sensor such as a thermocouple. In this way, the integrated control panel 50 monitors the temperature change of the electric motor 6, and detects an unexpected situation such as a failure of the electric motor 6 or a failure of the water cooling system based on the temperature detected by the temperature sensor 57.

Next, the function of the integrated control panel 50 according to the present embodiment will be described in detail with reference to fig. 5. Fig. 5 is a block diagram showing the control system of pile-pressing system 3. The items (1) to (8) shown in fig. 5 correspond to the following items (1) to (8) of information input/output between the respective components.

(1) From the control unit 8 to the integrated control panel 50: the rotation output information (real-time output, total value of torque (total value of a plurality of electric motors), average value, abnormality monitoring information, voltage value, current value, etc. of the electric motor 6) of the electric motor 6 is output.

(2) From the electric motor 6 to the integrated control panel 50: temperature information of the electric motor 6 is output.

(3) From the condition detection section 56 to the integrated control panel 50: outputs the hydraulic pressure of the hydraulic oil supplied to the lift cylinder 7, the mechanical attitude of the pile driver 1, the clamp safety state, and the like.

(4) From the integrated control board 50 to the control unit 8: the set torque (rotation torque signal) is calculated by calculating the press-in load and the pull-out load of the pile driving device 1 from the combination control panel 50, and an inverter command is output to the control unit 8 based on the calculated set torque. The inverter command includes a voltage increase, a stop of the electric motor, and the like.

(5) From the combination control board 50 to the lift oil pressure control valve 54: opening and closing signals of the valve. For example, the valve closing signal is output when the rotational torque reaches a predetermined value or more.

(6) From the electric oil pressure unit 9 to the integrated control panel 50: outputs a working oil state signal indicating the current pressure, flow rate, etc. of the working oil.

(7) From the integrated control panel 50 to the electric oil pressure unit 9: and outputting a pressure control request signal of the working oil. Upon receiving the pressure control request signal, the electric oil pressure unit 9 controls the pressure and flow rate of the working oil.

(8) From the integrated control panel 50 to the electric pump control section 58: based on the temperature information of the electric motor 6, a flow rate signal indicating the flow rate of the cooling water is output. The electric pump control unit 58 controls the cooling electric pump 59 to deliver the cooling water at a flow rate based on the flow rate signal.

As shown in (1) to (8) above, the integrated control board 50 receives various pieces of information indicating the mechanical state of the pile driving system 3, such as the press-in load, the pull-out load, the mechanical attitude, the clamp safety state, the temperature of the electric motor 6, and the state of the hydraulic oil, of the pile 4. The combination control panel 50 automatically controls the machine state so as to match the value (load, torque) arbitrarily set by the operator using the operation panel 51. The combination control panel 50 controls the load by controlling the relief pressure of the electric hydraulic unit 9, and controls the torque by controlling the inverter command of the control unit 8. In addition to the data shown in (1) to (8), signals such as error signals and abnormal signals are input and output between the respective components as necessary.

Hereinafter, various controls of the integrated control panel 50 according to the present embodiment will be described in detail.

The integrated control board 50 controls the lift cylinder 7 to move the collet 5 up and down based on the rotation output of the electric motor 6 when the pile 4 held by the collet 5 is pressed in. One example of controlling the rotation output in the present embodiment is controlling the rotation torque, but the present invention is not limited to this, and the control may be performed based on the rotation speed or a combination of the rotation torque and the rotation speed. In the present embodiment, the rotation of the chuck 5 is used as a trigger for lowering the chuck 5 by the lift cylinder 7. That is, the lift cylinder 7 does not lower the chuck 5 in a state where the chuck 5 is not rotated. In addition, when the collet 5 does not grip the pile 4, the lift cylinder 7 may lower or raise the collet 5 to perform position confirmation of the collet 5, and the like.

Here, calculation of the torque when the pile 4 is pressed in will be described.

First, the rotation torque signal (inverter command: set values of frequency and voltage) input to the control unit 8 from the integrated control panel 50 corresponds to the total amount of force received by the pile 4 from the ground. The ratio of the torque generated by the peripheral surface portion of the pile 4 to the tip end portion of the pile 4 differs depending on the ground conditions. The ratio of the torque can be estimated, for example, from a difference between the rotational torque of the collet 5 when the pile 4 is pressed in (hereinafter referred to as "pressing-in rotational torque") and the rotational torque of the collet 5 when the pile 4 is pulled out (hereinafter referred to as "pulling-out rotational torque"). The rotation torque at the time of press-fitting is the sum of the torque generated at the peripheral surface portion of the pile 4 and the torque generated at the tip end portion of the pile 4, and the rotation torque at the time of extraction is the torque generated at the peripheral surface portion of the pile 4. Therefore, the torque generated at the tip of the pile 4 can be calculated from the difference between the rotation torque at the time of press-fitting and the rotation torque at the time of withdrawal. Further, the ground information in the depth direction of the ground can be obtained from the rate of increase or decrease of the torque generated at the tip end of the pile 4.

In this way, the rotation output of the electric motor 6 reflects the ground information of the driven pile 4. Therefore, the pile driving system 3 controls the lift cylinder 7 based on the rotational output of the electric motor 6 to move the chuck 5 up and down, thereby realizing efficient construction. The pile driving system 3 of the present embodiment estimates the ground state by correlating measured values of the pile 4 pushing force, pulling force, and rotation torque, and can automatically operate by the optimum vertical stroke and rotation output of the collet 5.

The integrated control panel 50 of the present embodiment calculates a rotation output (rotation torque in the present embodiment) of the electric motor 6 based on an inverter command to the electric motor 6. This makes it possible to easily grasp the rotation output of the electric motor 6, in other words, the ground information.

Further, the integrated control panel 50 of the present embodiment performs overload protection, and stops the lowering operation of the chuck 5 by the lift cylinder 7 (hereinafter referred to as "chuck lowering operation") when the rotation output of the electric motor 6 reaches a predetermined value.

The overload protection of the present embodiment will be specifically described. First, the operator sets an upper limit torque, which is an upper limit of the rotational torque, by the operation panel 51. Then, the collet 5 holding the pile 4 is lowered in the press-in direction by the lift cylinder 7. The pile 4 is further rotationally driven by the chuck lowering operation, and when the driving force increases due to resistance of the ground surface to the tip end portion of the pile 4, the rotational torque of the electric motor 6 increases accordingly. When the rotational torque reaches the upper limit torque, the integrated control board 50 stops the lowering operation of the chuck 5, that is, the operation of the lift cylinder 7. This prevents the drill (claw) welded to the tip of the pile 4 from being damaged by excessive ground resistance. Further, the integrated control panel 50 outputs a valve closing signal to the lift hydraulic control valve 54 and outputs stop signals of the hydraulic pump 11 and the electric motor 12 to the electric hydraulic unit 9 to stop the operation of the lift cylinder 7.

The integrated control panel 50 of the present embodiment controls the rotation output of the electric motor 6 in accordance with the load state of the electric motor 6. One example of the load state of the electric motor 6 is determined based on a value (current value) of a current output from the inverter device 10 to the electric motor 6. More specifically, the difference between the current value actually output to the electric motor 6 (hereinafter referred to as "actual current value") and the upper limit current value predetermined as the upper limit current value is the load state, and the smaller the difference, the higher the load state.

That is, the integrated control panel 50 monitors the load state of the electric motor 6 in real time, and temporarily increases the normal torque excessively (hereinafter, referred to as "torque boosting") by inverter control, thereby controlling the rotary pile 4 and controlling the torque limitation according to the load state. If the torque rises within the output (product of the total rotational speed and the torque value) of the electric motor 6, the torque is increased above the rated value (100%).

Here, the torque boosting will be described with reference to fig. 6. Fig. 6 is a graph showing rotation characteristics of the hydraulic motor and the electric motor, where 6(a) shows the rotation characteristics of the hydraulic motor, and 6(b) shows the rotation characteristics of the electric motor. As shown in fig. 6(a), when the rotation torque of the hydraulic motor is 100%, the hydraulic relief control is executed so that the flow rate of the hydraulic oil becomes 0 and the rotation is stopped. On the other hand, as shown in fig. 6(b), the electric motor may output the rotation speed at the intersection with the output line even when the torque is 100%, and further, may output 100% or more by the torque boosting. That is, even if the pile 4 pushing force is increased, the rotation speed of the hydraulic motor is reduced before the set torque (torque 100%) is reached, and therefore, the torque boosting cannot be achieved. On the other hand, the electric motor can achieve torque boosting without stopping rotation. Therefore, the electric motor can be set to a torque of 100% (rated) or more which cannot be achieved by the hydraulic motor.

Therefore, the integrated control panel 50 performs torque boosting to temporarily increase the rotation torque in accordance with the load state of the electric motor 6, that is, when there is a margin in the load of the electric motor 6, and thus, efficient construction can be achieved. Further, since the load of the electric motor 6 is increased, the torque boosting is performed only for a short time.

The integrated control panel 50 performs control to reduce the rotation output of the electric motor 6 when the load state of the electric motor 6 is excessively large. The determination of the excessive load state may be made not only from the difference between the actually measured current value and the upper limit current value, but also when the temperature of the electric motor 6 becomes equal to or higher than a predetermined value.

In addition, in the normal control, the cooling water flows uniformly at a constant flow rate to each electric motor 6, but the integrated control board 50 of the present embodiment may control the cooling amount of the cooling water in accordance with the rotation output or the load state of the electric motor 6. That is, the combination control board 50 outputs a control signal to the electric pump control unit 58 so that the flow rate of the cooling water is increased as the rotation output of the electric motor 6 is increased or the load state is increased.

Further, the combination control board 50 is set to a high load state when the temperature sensor 57 provided in each electric motor 6 detects a temperature equal to or higher than a predetermined value, and outputs a control signal to the electric pump control unit 58 so as to increase the flow rate of the cooling water.

Further, the pile driver 1 of the present embodiment can replace the collet 5 according to the ground state. Fig. 7 is a configuration diagram showing the replacement collet 5 of the pile driver 1 according to the present embodiment. In the pile driver 1 of the present embodiment, the structure including the collet 5, the lift cylinder 7, and the like (hereinafter referred to as "collet ASSY") can be replaced according to the ground state.

The chuck ASSY60A shown in fig. 7 is of a hydraulic standard rotation specification, and the chuck 5 is rotated by the hydraulic motor 61. Further, chuck ASSY60B is of a hydraulic high output rotation standard, and chuck 5 is rotated at high output by increasing the number of hydraulic motors 61 to be larger than that of chuck ASSY 60A. Chuck ASSY60C is an electric high-output rotation standard for rotating chuck 5 by electric motor 6 of the present embodiment.

When the cartridge ASSY60A or the cartridge ASSY60B is used, the oil supply line 53B and the hydraulic motor 61 are connected via the rotary oil pressure control valve 55, and the hydraulic oil is supplied from the electric hydraulic unit 9 to the hydraulic motor 61.

Further, a pod ASSY60B of a hydraulic high-output rotation standard is attached to the mast 20, and includes a rotation hydraulic control valve 55 corresponding to the hydraulic motor 61 added and a relay control panel for relaying various information input from the hydraulic motors 61 and outputting the information to the integrated control panel 50.

Further, the chuck ASSY60C of the electric high output rotating standard is provided with a binding member 62 attached to the mast 20, and the binding member 62 integrates the cooling pipe 41 through which the cooling water for cooling the electric motor 6 flows and a hanger of a hydraulic pipe for supplying the hydraulic oil to the lift cylinder 7. Thus, even when the chuck ASSY60C of the electric high output rotation standard is used, the cooling pipe 41 and the hydraulic pipe are bundled by the bundling member 62, and the efficient replacement work is performed.

The present invention has been described above with reference to the above embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments. Various changes or improvements may be made to the above-described embodiments without departing from the scope of the invention, and the modified forms are also included in the technical scope of the present invention.

(modification example)

In the present modification, the cooling mechanism of the electric motor 6 is of an external fan type. That is, the electric motor 6 of the present modification is cooled by air cooling. Fig. 8 is a schematic configuration diagram of a cooling mechanism of the electric motor 6 according to the present modification, and the cooling mechanism of the electric motor 6 is a fan 65 provided in the electric motor 6.

In the example of fig. 8, the fan 65 is disposed above the electric motor 6, and the rotary shaft 65A of the fan 65 is directly connected to the rotary shaft 6A of the electric motor 6. Thereby, the fan 65 obtains a driving force from the electric motor 6, so that the electric motor 6 can be cooled by a simple configuration. In fig. 8, the electric motor 6 and the reduction gear 42 are coupled via the base 66, but this is merely an example, and the electric motor 6 and the reduction gear 42 may not be coupled via the base 66.

In this modification, the fan 65 blows air to cool the lower side of the electric motor 6. Further, the plurality of fans 67 are provided on the surface of the electric motor 6 in the height direction of the electric motor 6, i.e., the air blowing direction. This increases the surface area of the electric motor 6, and improves the cooling effect of air cooling. Further, although the reducer 42 of the present modification is cooled by cooling water by disposing the cooling pipe 41, the present invention is not limited to this, and cooling may be performed by air cooling if the capacity of the fan 65 is sufficient. In this way, the present modification cools the electric motor 6 by air cooling, and thus can cool the electric motor with a simple configuration.

The fan 65 may be provided independently of the rotary shaft 6A of the electric motor 6. When the rotating shaft 65A of the fan 65 is coupled to the rotating shaft 6A of the electric motor 6, the cooling amount of the fan 65 depends on the rotation speed of the electric motor 6, and it is difficult to control the cooling amount of the fan 65. Therefore, when the rotary shaft 65A of the fan 65 is not coupled to the rotary shaft 6A of the electric motor 6, the cooling amount of the fan 65 can be controlled without being restricted by the rotation speed of the electric motor 6.

That is, the integrated control board 50 controls the cooling amount of the fan 65 independent of the rotation shaft 6A of the electric motor 6 in accordance with the rotation output or the load state of the electric motor 6. More specifically, the integrated control board 50 controls the rotation speed of a motor (hereinafter referred to as "fan drive motor") for rotating the fan 65 in accordance with the rotation output or the load state of the electric motor 6. For example, the integrated control board 50 controls the fan drive motor such that the rotation speed of the fan 65 is higher as the rotation output of the electric motor 6 is higher or the load state of the electric motor 6 is higher. Thus, pile driving system 3 can effectively cool electric motor 6.

Description of the symbols:

1, pile pressing device;

5, a clamping head (a rotating mechanism);

6 electric motors (motors);

7 lift cylinders (oil hydraulic);

11 a hydraulic pump (hydraulic pressure generating device);

20 masts;

41 cooling piping (cooling mechanism);

42 a decelerator;

50 integrated control panel (control mechanism);

61 a binding member;

65 fan (cooling mechanism).