阅读说明：本技术 枪钻机 (Gun drill ) 是由 稻田博 稻田英教 佐藤优幸 于 2020-03-17 设计创作，主要内容包括：本发明的课题在于开发一种枪钻机,其可将枪钻中必然产生的边界尺寸尽可能地缩短。本发明的特征在于：在切屑箱(3)、与移动的主轴单元(2)间的自由区(Z),设置松保持枪钻(5)并抑制其振动的复数个止振装置(6)；并且各止振装置(6)是可从进行止振作用的稳定作用位置自由退去地构成,以避免干扰于自由区(Z)中移动而来的主轴单元(2)。(The invention aims to develop a gun drill, which can shorten the boundary size inevitably generated in the gun drill as much as possible. The invention is characterized in that: a plurality of vibration-stopping devices (6) for loosening and holding the gun drill (5) and suppressing the vibration thereof are arranged in a free area (Z) between the chip box (3) and the moving spindle unit (2); and each vibration stopping device (6) is freely retreated from a stable action position for stopping vibration so as to avoid interference with the spindle unit (2) moving in the free zone (Z).)

1. A gun drill is provided with a bed, a spindle unit, a chip box, and a workpiece holder;

the main shaft unit is used for holding a gun drill and moving in a range from a moving starting end to a moving terminal end on the bed;

the chip box is arranged at the mobile terminal side of the main shaft unit and can freely and rotatably support the gun drill;

the work holder is disposed adjacent to the chip box on the opposite side of the spindle unit;

moving the front end of the gun drill held by the spindle unit from the chip box to the workpiece held by the workpiece holder;

drilling a deep hole in the workpiece by rotating the main shaft of the main shaft unit and advancing the main shaft unit; it is characterized in that the preparation method is characterized in that,

a plurality of vibration stopping devices for loosening and holding the gun drill and inhibiting the vibration of the gun drill are arranged in a free area between the chip box and the movable main shaft unit; and is

Each vibration stopping device is freely retreated from a stable action position for stopping vibration so as to avoid interference with the main shaft unit moving in the free zone.

2. The gun drill according to claim 1,

the vibration stopping device is provided with a finger-shaped unit for directly loosening and holding the gun drill; the finger unit is opened and closed by a pair of fingers to release the gun drill.

3. The gun drill according to claim 1 or 2,

the vibration stopping device moves to make the finger unit fall down and reach the stable action position of the gun drill from the retreating position.

4. The gun drill according to claim 3,

the vibration stopping device is provided with a fluctuation arm and a switch chain supported by the fluctuation arm; the heave arm is arranged on the bed side in a manner of freely rotating in the arm pivot of the base end of the heave arm and supports the switch chain in a manner of freely rotating on the free end side; finger units are formed by fingers arranged on the side of the fluctuation arm and fingers arranged on the side of the switch chain; the whole oscillation stop device is moved up and down and the two fingers constituting the finger unit are switched on and off by the displacement device.

5. The gun drill according to claim 4,

a switch chain of the vibration damper, which is rotatably provided on the heave arm at a switch chain pivot in the middle part thereof, and which has a finger formed on a free end side thereof and a displacement receiving part formed on a rear end side thereof, and to which a displacement rod of a displacement cylinder for pulling up the heave arm in a rising and retreating direction is connected; the vibration stopper is configured to loosely hold a gun drill by a finger unit at an extended position of a displacement lever, and to rotate a switch chain about a switch chain pivot by contraction of the displacement lever, thereby withdrawing a finger on the switch chain side to a chin-open state, and further to rotate and displace the entire heave arm in the rising direction.

6. The gun drill according to claim 1 or 2,

the vibration stopping device is provided with a sliding unit arranged in a free area, a finger-shaped unit arranged at the free end part of the sliding unit and a displacement device for driving the sliding unit; the sliding unit moves in the direction orthogonal to the arrangement direction of the gun drill on the bed and moves the finger unit to a stable action position for loosening and holding the gun drill; the finger unit is a finger switch for releasing and releasing the gun drill.

7. The gun drill according to claim 1, 2, 3, 4, 5, or 6 wherein,

the plurality of vibration stopping devices fix the arrangement positions in the long side direction of the free area.

Technical Field

The present invention relates to a gun drill for deep hole drilling of a workpiece, and more particularly, to an improvement of a gun drill which stabilizes the operation of the gun drill and enables accurate deep hole drilling.

Background

As is well known, a gun drill for deep hole drilling of a workpiece has an operation principle of rotationally driving a long gun drill having a special cross-sectional shape and causing the gun drill to act in the workpiece to drill a hole; if the hole diameter and the machining depth can be processed by a conventional method, a machining technique is established (for example, see patent document 1). Additionally, the deep hole processing means that holes having a ratio of hole size to diameter, that is, an L/D value of 20 to 200 or more are formed.

On the other hand, in the case where the machining requirement specifications are extremely strict, development of the entire apparatus and accumulation of a large amount of expertise are required.

Specifically, as an example of the specification required for difficult working, a workpiece made of a hard stainless steel is assumed, and the working size is 1mm or less in diameter and more than 200mm in hole length.

In the case of such a specification, it is a matter of course that the gun drill is a gun drill having a penetration hole diameter of 1mm and a full length of about 300mm including a boundary portion not directly related to the penetration hole. Further, the shape of the gun drill is a shape of a circle portion such as 1/4, and is not a complete circular cross-sectional shape. It is extremely difficult to rotate it stably, and accurate machining has been considered impossible to perform.

That is, as shown in fig. 12 (a), even if the gun drill 5 'and the machining end side of the workpiece W are accurately controlled by the chip box 3', the gun drill 5 'is in a state of a rope skipping phenomenon or a bulging (balling) phenomenon in which the gun drill 5' is bent in a spindle shape accompanying high-speed rotation (for example, rotation at about 12000 rpm) of the gun drill 5 'in the middle thereof, and naturally, the movement also induces breakage of the gun drill 5'.

Therefore, conventionally, as shown in fig. 12 (b), a vibration stopper 6 'for stabilizing the gun drill 5' is disposed in the free zone Z between the chip box 3 'and the spindle unit 2'. However, as shown in fig. 12 (c), the vibration damping bush 63 ' is pushed and moved in a manner of being pushed out in order from the base end side only in accordance with the movement of the spindle unit 2 ', and as a result, the position where the vibration damping control of the gun drill 5 ' is performed is not at the uniform position in the range of the free zone Z.

That is, in the state shown in fig. 12 (b), even if the distance between the nut 27 'for the chuck and the vibration damping bush 63', the distance between the vibration damping bush 63 ', and the distance between the vibration damping bush 63' and the Gizmo seal (japanese: ギズモシール)31 'are set to be the same interval d0, the distance between the nut 27' and the vibration damping bush 63 'on the most proximal end side is gradually shortened with the movement of the spindle unit 2', and thus the distance is different from the interval d 0. Specifically, as shown in fig. 12 (c), the interval dx between the base end and the lateral side is shorter than the interval d 0.

Therefore, although the gun drill 5' is held, a complete vibration stopping effect cannot be expected.

In view of such circumstances, the present applicant has developed a novel gun drill which can stabilize the operation of the gun drill and achieve accurate deep hole processing by performing vibration stopping control of the gun drill at an equal position in the range of the free zone all the time, and the technique has been disclosed in japanese patent laid-open No. 2018-62035 (patent document 1).

The present inventors have found that, as a result of the present invention, the actual length dimension of the gun drill has to be far greater than the effective length of the gun drill. That is, the length of the gun drill must be a length that is a length that acts on the workpiece plus a dimension that passes through the chip box, a dimension that avoids interference with the vibration stopper remaining in the free zone, or a so-called dimension plus a boundary dimension. Such a long-sized gun drill naturally causes the action state of the tip thereof to be unstable.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2018-once 62035

Disclosure of Invention

Problems to be solved by the invention

The present invention has been made in view of such a background, and an object thereof is to develop a gun drill capable of reducing a boundary dimension inevitably generated in the gun drill as much as possible.

Means for solving the problems

That is, the gun drill of claim 1 is provided with a bed, a spindle unit, a chip box, and a work holder; the main shaft unit is used for holding a gun drill and moving in a range from a moving starting end to a moving terminal end on the bed; the chip box is arranged at the mobile terminal side of the main shaft unit and can freely and rotatably support the gun drill; the work holder is disposed adjacent to the chip box on the opposite side of the spindle unit; moving the front end of the gun drill held by the spindle unit from the chip box to the workpiece held by the workpiece holder; drilling a deep hole in the workpiece by rotating the main shaft of the main shaft unit and advancing the main shaft unit; characterized in that a plurality of vibration stopping devices for loosening and holding the gun drill and inhibiting the vibration of the gun drill are arranged in a free area between the chip box and the movable main shaft unit; and each vibration stopping device is freely retreated from a stable action position for stopping vibration so as to avoid interference with the main shaft unit moving in the free zone.

The gun drill according to claim 2 is characterized in that the vibration stopper includes, in addition to the above-described elements, a finger unit for directly loosening and holding the gun drill; the finger unit is opened and closed by a pair of fingers to release the gun drill.

The gun drill according to claim 3 is characterized in that the vibration stopper is moved to collapse the finger unit and move the finger unit from the retreated position to the stable operation position of the gun drill, in addition to the above-mentioned elements.

The gun drill according to claim 4 is characterized in that the vibration stopper is a switch chain including a heave arm and supported by the heave arm, in addition to the above-described elements; the heave arm is arranged on the bed side in a manner of freely rotating in the arm pivot of the base end of the heave arm and supports the switch chain in a manner of freely rotating on the free end side; finger units are formed by fingers arranged on the side of the fluctuation arm and fingers arranged on the side of the switch chain; the whole oscillation stop device is moved up and down and the two fingers constituting the finger unit are switched on and off by the displacement device.

The gun drill according to claim 5 is characterized in that, in addition to the above-mentioned elements, the switch chain of the vibration damper is rotatably provided on the raising and lowering arm at a switch chain pivot in an intermediate portion thereof, and a finger is formed on a free end side thereof, and a displacement receiving portion is formed on a rear end side thereof, and a displacement rod of a displacement cylinder which pulls up the raising and lowering arm in a raising and lowering direction is connected thereto; the vibration stopper is configured to loosely hold a gun drill by a finger unit at an extended position of a displacement lever, and to rotate a switch chain about a switch chain pivot by contraction of the displacement lever, thereby withdrawing a finger on the switch chain side to a chin-open state, and further to rotate and displace the entire heave arm in the rising direction.

The gun drill according to claim 6 is characterized in that the vibration stopper includes, in addition to the above-described elements, a slide unit provided in a free area, a finger unit provided at a free end of the slide unit, and a displacement device for driving the slide unit; the sliding unit moves in the direction orthogonal to the arrangement direction of the gun drill on the bed and moves the finger unit to a stable action position for loosening and holding the gun drill; the finger unit is a finger switch for releasing and releasing the gun drill.

Further, the gun drill according to claim 7 is characterized in that the plurality of vibration stoppers fix the installation positions in the longitudinal direction of the free space in addition to the above-described elements.

Effects of the invention

First, according to the invention described in claim 1, as the main shaft unit approaches the chip box side as the hole is drilled by the gun drill, the free area gradually narrows, and at this time, the vibration damper is retracted to avoid interference with the main shaft unit, so that the main shaft unit can approach the chip box side as close as possible. As a result, the length of the gun drill can be made shorter than that of the conventional gun drill, and the drilling effect can be stabilized.

Further, according to the invention described in claim 2, the gun drill is loosely held by the finger unit having the pair of fingers, the vibration stopper can be smoothly set and retracted, and a stable vibration stopping action can be expected.

Further, according to the invention described in claim 3, the vibration stopper is of a chain type structure, and holds the gun drill at the lodging position, and the space at the back side after the gun drill arrangement position can be effectively utilized.

Further, according to the invention described in claim 4, the finger provided in the vibration damping device is provided with the seesaw arm which performs the seesaw operation and the switch chain provided thereto, and the finger unit is moved appropriately when the finger unit is operated and when the finger unit is not operated.

Further, according to the invention described in claim 5, the vibration damping device is configured to perform opening and closing of the finger unit and tilting of the heave arm by one displacement cylinder, and a simple driving mode can be obtained.

Further, according to the invention described in claim 6, the movement of the vibration damper is a simple sliding motion, and the entire structure can be made simple. Therefore, even when the gun drill diameter is extremely small, for example, 1mm or less, the hole is short and the free space is short, a large number of vibration dampers can be densely arranged.

Further, according to the invention described in claim 7, the plurality of vibration dampers are individually disposed in a fixed position in the longitudinal direction of the free area, and a reliable installation manner can be obtained.

Drawings

Fig. 1 is a front view of a gun drill according to the present invention, and a side view and an oblique view partially enlarged.

Fig. 2 is a front view of the upper gun drill, and shows a partially enlarged spindle unit, a chain type vibration damping device, a chip box, and a work retainer.

Fig. 3 is a plan view showing a gun drill of the present invention.

Fig. 4 is an enlarged side view of the chain-type vibration damper.

Fig. 5 is an exploded perspective view showing a chain type vibration damper.

Fig. 6 is a side view showing the movement of the chain type vibration damper in stages.

Fig. 7 is a side view showing a slide type vibration damper.

Fig. 8 is a plan view showing a slide type vibration damper.

Fig. 9 is a perspective view showing a slide type vibration damper.

Fig. 10 is a side view and a plan view showing another embodiment of the slide type vibration damper.

Fig. 11 is a side view showing the movement of the spindle unit, the chain type vibration damping device, the chip box, and the work holder in stages.

Fig. 12 is a front view showing a conventional gun drill and a vibration stopping device.

Detailed Description

The best mode of the present invention is described in the following examples, but may be modified as appropriate within the scope of the technical idea of the present invention.

In the following description, first, the configuration of the gun drill 1 according to the present invention will be described, and then, the operation of the apparatus will be described.

[ examples ]

As shown in fig. 1 and 2, a gun drill 1 according to the present invention includes: a bed B, a spindle unit 2 which holds a gun drill 5 and moves on the bed B in a range from a movement start end to a movement end, a chip box 3 which is provided at the movement end of the spindle unit 2 and rotatably supports the gun drill 5, a work holder 4 which is disposed adjacent to the chip box 3 on the opposite side of the spindle unit 2, and a vibration stopper 6(7) which loosely holds the gun drill 5 between the spindle unit 2 and the chip box 3.

With the gun drill 1, the tip of the gun drill 5 held by the spindle unit 2 is moved from the chip box 3 to the workpiece W held by the workpiece holder 4, and a deep hole H is drilled in the workpiece W by the rotation of the spindle 23 in the spindle unit 2 and the advance of the spindle unit 2.

Next, in a free zone Z between the chip box 3 and the moving spindle unit 2, a plurality of vibration stopper devices 6 and 7 are provided with a plurality of seats in the axial direction of the gun drill 5, and each vibration stopper device 6 and 7 is configured to be able to retreat from the position in order to avoid interference with the spindle unit 2 by loosely holding the gun drill 5.

Hereinafter, each element constituting the gun drill 1 will be described in detail.

First, the spindle unit 2 has, as an example, the same structure as that disclosed in japanese patent application laid-open No. 2012 and 86312 "gun drill" of the present applicant. Specifically, as shown in fig. 2, a stator 21 and a rotor 22 are provided in a housing 20, and a main shaft 23 of the rotor 22 is supported by a pair of bearings 24 provided at both ends of the housing 20 so as to face each other.

Next, an oil hole 25 is formed through the axial center of the main shaft 23, an oil supply pipe 26 is connected to one end of the main shaft 23, and a nut 27 for a chuck of the gun drill 5 is connected to the other end.

The spindle unit 2 having such a configuration is configured to be movable along the axial direction of the spindle 23 on a rail R2 laid on the bed B by a ball screw mechanism or the like (not shown).

Next, the chip box 3 is a device for rotatably supporting the tip side of the gun drill 5 and recovering chips generated from the workpiece W, and is also a device for holding the workpiece W, and is fixedly provided between the spindle unit 2 and the workpiece holder 4 on the bed B.

Specifically, as shown in fig. 2, a cartridge 35 is rotatably provided on one side of the housing 30, and a protective seal 31 is rotatably provided on the opposite side of the cartridge 35. The gun drill 5 is inserted into the drill hole 31a of the protective seal 31 and the drill hole 32a of the drill bushing 32, and the tip of the gun drill 5 protruding from the drill hole 32a acts on the workpiece W contacting the drill bushing 32.

Further, a support bushing in which a drill hole is formed may be provided between the protective seal 31 and the drill bushing 32, so that the gun drill 5 can be more reliably held.

Next, the work retainer 4 is a device for retaining the work W machined by the gun drill 1 between the work retainer and the chip box 3, and in this embodiment, the work W is rotated in a direction opposite to the rotation direction of the gun drill 5.

Specifically, as shown in fig. 2, the output shaft of the relative rotation unit 41, which is formed by combining suitable gears, is provided with the chuck 42 and the motor M4 for driving the relative rotation unit 41.

Further, the workpiece holder 4 is configured such that the collet 42 is disposed to face the collet 35 in the chip box 3, and further configured such that the distance between the collet 42 and the collet 35 can be adjusted by moving on a rail R4 laid on the bed B along the axial direction of the spindle 23 in the spindle unit 2, thereby enabling workpieces W of various lengths to be held.

The form of the workpiece holder 4 may be a table (table) that is fixed without rotating the workpiece W.

Next, the gun drill 5 is a drill for deep hole drilling (L/D value 20 to 200), and as an example of specifications required for difficult machining, it is assumed that feasible machining conditions are: the workpiece W is made of hard stainless steel or titanium material, and the deep hole H has a diameter of 1mm or less and a hole length of more than 200 mm.

In the case of such a specification, the entire length of the gun drill 5 including the boundary portion not directly related to the through-hole is about 300mm, but the boundary portion may be about half as long according to the present invention, and the entire length may be about 250mm, for example.

Further, as shown enlarged in fig. 2, the cross-sectional shape of the gun drill 5 is not a perfect circular cross-sectional shape, but a V groove 51 is formed by cutting out almost 1/4 circumferential portions from a circular shape. Further, one or a plurality of oil holes 52 are formed through the gun drill 5 in the axial direction.

In fig. 2, although the axes of the oil hole 25 in the main shaft 23 and the oil hole 52 in the gun drill 5 are offset, since the nut 27 for the collet exists therebetween, the movement of the cutting oil from the oil hole 25 to the oil hole 52 can be smoothly performed by providing a location for accumulation of the cutting oil in the nut 27.

Next, the vibration damping devices 6 and 7 having the main object of the present invention will be described. The vibration dampers 6 and 7 are devices for suppressing a state of a rope skipping phenomenon or a balloon phenomenon that is bent in a spindle shape with high-speed rotation of the gun drill 5 at, for example, about 12000 rpm.

The vibration stopper devices 6 and 7 of the present invention are configured to be able to retreat from a stable operation position of the loose-holding gun drill 5 to avoid interference with the spindle unit, and have two configurations. One of them is a chain type vibration damper 6 whose movable system is a combination of chains, and the other is a slide type vibration damper 7 which moves horizontally as an example of the movable system.

Chain-type vibration damping device

First, the chain-type vibration damping device 6 will be described with reference to fig. 1 to 6 and 11. The vibration stopper 6 is disposed in the back space of the actual machining operation space of the main shaft unit 2 or the gun drill 5 in the gun drill 1, and a plurality of support columns 60 as frame members are disposed side by side along the free zone Z. First, the support column 60 has its upper portion as a cylinder support 60A and its portion extending from the vicinity of the middle height toward the front side as an arm support 60B. For such a support column 60, first, a raising and lowering arm 61 is freely rotatably provided. That is, the raising and lowering arm 61 is a long plate-like member, and its base is an arm pivot 61P, and this is pinned to the arm stay 60B in the support column 60.

As a result, the heave arm 61 is configured to receive the action of a displacement cylinder 66, which will be described later, with the lower end as the center, and to be rotated from a stable action position, which is substantially horizontal, to a retreat position, in which the free end rises upward.

Further, the undulation arm 61 is provided at its free end with a finger 61F for loosely holding one side of the finger unit 65 of the gun drill 5. A vibration stopping guide 62 made of a material suitable for preventing smooth rotation of the gun drill 5 is fixed to the finger 61F on the side of the undulation arm 61; a guide groove 62A as a receiver of the gun drill is formed in the vibration damper guide 62. The reference numeral 61S denotes an arm setting spring extending between the arm stay 60B and the lower side of the heave arm 61, and the arm setting spring holds the heave arm 61 in a posture at the retreated position and slightly biases the heave arm 61 to fall after the heave arm 61 starts to fall.

To this raising arm 61, a switch chain 63 including a finger 63F on the other side of the finger unit 65 is rotatably mounted. That is, the switch chain 63 is a plate-like chain member having a somewhat deformed three-forked shape, and a switch chain pivot 63P is formed at a portion projecting upward in the drawing at the intermediate portion, and is pin-connected to the undulation arm 61 at a position closer to the free end thereof and rearward of the finger 61F. The switch chain 63 is a finger 63F whose free end side is a switch chain side, and a vibration stopping guide 64 having a guide groove 64A formed therein in the same manner as the finger 61F on the side of the seesaw arm is fixed to this portion. The pair of fingers 61F, 63F constitutes a finger unit 65.

Further, a rearward projecting portion of the switch chain 63 is defined as a displacement passive portion 63D, and a displacement rod 67 of a displacement cylinder 66 described later is pinned to this portion. The reference numeral 63S denotes a chain setting spring that biases the finger 63F on the switch chain 63 side to be always open.

Next, the displacement cylinder 66 for tilting and lifting the heave arm 61 including the switch chain 63 will be described. In this embodiment, the displacement cylinder 66 is arranged in a state in which the displacement rod 67 is directed downward and slightly tilted backward from an upright state, and first, an upper cylinder pivot 66P is pinned to an upper end of the cylinder support 60A of the support column 60. On the other hand, the downward displacement rod 67 is pinned to the displacement passive portion 63D of the switch chain 63 at its rod end 67E at a rod pivot 67P.

As an example of the displacement cylinder 66, a pneumatic cylinder is preferable from the viewpoint of control and maintenance, but a hydraulic cylinder, a motor cylinder, or the like may be used. Of course, other torque actuators and the like may be applied as long as the required operations such as rotation of the heave arm 61 and rotation of the switch chain 63 can be achieved

Here, the operation of the chain-type vibration damping device 6 will be described with reference to fig. 6.

i) Initial state of vibration-stopping device

As shown in fig. 6 (a), the initial state is a state in which the finger unit 65 as a steady operation state is released from the gun drill 5. In this state, the displacement rod 67 of the displacement cylinder 66 is in a fully extended state, the heave arm 61 is in a state of being almost horizontally collapsed, and the fingers 61F and 63F of the finger unit 65 are in a closed state. Further, the finger unit 65 secures the guide hole of the gun drill 5 and loosely holds the gun drill 5 by the presence of the guide grooves 62A, 64A shown in fig. 5. As is apparent from the plan view of fig. 3, the vibration damping device 6 is located at a position where it interferes with the spindle unit 2, and therefore, in order to avoid interference, the operation of retreating from this position is performed.

ii) the retreating action of the vibration-stopping device

The vibration damper 6 is operated by a displacement cylinder 66 as an actuator to change a displacement rod 67 in the displacement cylinder 66 from an extended state to a contracted state.

ii-1) opening of the switch chain

At this time, since the displacement lever 67 is not directly connected to the heave arm 61 but connected to the displacement passive section 63D with respect to the switch chain 63, the contraction operation of the displacement lever 67 first rotates the switch chain 63 about the switch chain pivot 63P in a diagonally downward direction with the finger 63F thereof. That is, the finger 63F moves as if to be in a chin-open state with respect to the finger 61F on the side of the raising arm 61, and first releases the holding of the lower side of the gun drill 5 as shown in fig. 6 (b).

ii-2) carrying of the heave arm

Then, as shown in fig. 6 (e), when the displacement rod 67 is further contracted, the switch chain 63 pulls up the displacement passive part 63D, and this movement is substantially transmitted to the raising arm 61 through the switch chain pivot 63P, so that the free end side is raised. As a result, the raising and lowering arm 61 raises its free end side about the arm pivot 61P, and finally, as shown in fig. 6 (d), when the displacement rod 67 of the displacement cylinder 66 is completely contracted, the raising and lowering arm 61 is in a substantially upright state, and in this state, the raising and lowering arm 61 is maintained in the upright state.

Further, when the raising and lowering arm 61 is gradually raised, the switch chain side finger unit 63F below the finger unit 65 is retreated to the chin on state moving obliquely downward as described above, but interference with the gun drill 5 is sufficiently avoided as compared with the case where the gun drill 5 is retreated to the rear.

iii) Retention of the vibration-damping device

When the holding gun drill 5 is released again from the state where the vibration damper 6 is withdrawn, the displacement rod 67 of the displacement cylinder 66 is gradually extended in contrast to the previous withdrawal operation. By this operation, as shown in fig. 6 (b), first, the raising and lowering arm 61 is lowered to the horizontal position, and the gun drill 5 is held from above by the finger 61F at the tip end thereof. Then, when the displacement lever 67 continues to extend, the switch chain 63 rotates clockwise in the drawing about the switch chain pivot 63P, and as shown in fig. 6 (a), the finger 63F is displaced to a so-called chin-off state, and the gun drill 5 is held by being released from the finger 61F.

Vibration damping device of sliding type

Next, another type of the slide type vibration damping device 7 will be described, and then, the operation of the entire gun drill 1 will be described. The sliding type vibration damper 7 has two embodiments, one of which is a complex cylinder type shown in fig. 7, 8 and 9, and displacement and sliding displacement of the finger unit 75 are performed by separate actuators. The other is a single cylinder type shown in fig. 10, which performs opening and closing of the slide displacement and finger unit with only one slide displacement cylinder 78 as an actuator.

Multiple cylinder type

First, an embodiment in which the displacement and the sliding displacement of the finger unit are performed by individual actuators will be described. As shown in fig. 7, 8, and 9, a guide rail 70 is disposed on the bed B so as to be orthogonal to the direction in which the gun drill 5 is disposed, and a slide unit 71 is provided to the guide rail 70 so as to be slidable.

The slide unit 71 includes a linear guide 72G directly fitted to the guide rail 70 on a lower surface of a slider 72, which is a part of the slide unit, and a finger rest 73 on a front side thereof. A slide displacement cylinder 78, which is a displacement device described later, is provided behind the slide unit 71, and this performs slide displacement of the slide unit 71.

The finger rest 73, which is a member in front of the slide unit 71, extends forward in a floating manner as viewed from the guide rail 70, and has a finger unit 75 formed of a pair of upper and lower fingers 75A and 75B at its front end via a switch guide 74.

That is, the pair of fingers 75A and 75B move up and down relatively to each other, respectively, to approach and separate from each other, as shown in fig. 7 and 8. Such linear movement in the up-down direction is obtained by the switch guide 74, and a guide means of an engagement shape or a dovetail groove shape is used. Further, the upper and lower fingers 75A and 75B are provided with vibration stopping guides 75G at their distal ends, as in the chain-type vibration stopping device 6. Further, the pair of upper and lower fingers 75A and 75B are vertically displaced relative to each other, and a finger shifter 76 as a driving member is provided at the rear.

The finger displacer 76, has two finger displacers arranged side by side: an upper finger shifter 76A for shifting the upper finger 75A, and a lower finger shifter 76B for shifting the lower finger 75B.

Next, a displacement device for sliding the displacement slide unit 71 as a whole will be described. To the bed B, a cylinder support 77 is provided at the rear end thereof, and a slide displacement cylinder 78 as a displacement means is mounted therein

The slide displacement cylinder 78 is also preferably a pneumatic cylinder, as with the displacement cylinder 66 described above, and other hydraulic cylinders and motor cylinders may be used. Further, the displacement device may be a device that drives the sliding unit 71 to move forward and backward by a rack and pinion mechanism or the like, instead of a cylinder type. The displacement rod 79 is a slider 72 having a front end connected to the slide unit 71, and the entire slide unit 71 is driven to slide back and forth by expansion and contraction of the slider.

The operation state of the sliding type vibration damping device 7 having the above-described configuration will be described.

i) Initial state

The initial state is a stable operation state of the vibration damper 7, and the slide unit 71 is in a position extending most forward by receiving the extension of the displacement rod 79. And the finger unit 75 at the foremost end is formed by approaching the upper and lower fingers 75A and 75B to each other and loosely holding the gun drill 5, thereby achieving the vibration damping effect.

ii) the retreating action of the vibration-stopping device

On the other hand, when the vibration damper 7 is retracted, first, the upper finger shifter 76A and the lower finger shifter 76B of the finger shifter 76 are operated to respectively move the upper and lower fingers 75A and 75B in the vertical direction. Whereby the holding of the gun drill 5 by the finger unit 75 is released.

When the displacement rod 79 of the slide displacement cylinder 78 is contracted in this state, the slide unit 71 connected thereto retreats to the rear with the finger unit 75.

iii) Return action (gun drill loose hold)

This action is performed in the reverse order of the retreat action, first, the slide unit 71 is advanced by the slide displacement cylinder 78, and then the finger unit 75 operates to release the holding gun drill 5.

Single cylinder type

Next, a description will be given of a single-cylinder type embodiment in which only one slide displacement cylinder 78 performs slide displacement of the slide unit 71 and displacement of the finger unit 75.

The vibration stopper 7 of the single cylinder type is shown in fig. 10 in a side view (a) and a plan view (b). Note that the same reference numerals are given to members common to the conventional double cylinder type vibration damping device 7. The slide unit 71 is almost common, and slides on a guide rail 70 provided on the bed B in a direction orthogonal to the extending direction of the gun drill 5. Further, a finger rest 73 is provided at the tip of the slide unit 71, and upper and lower fingers 75A and 75B are supported by the finger rest, and the finger unit 75 is rotatably attached so as to perform a scissor-like operation in a state where a constant opening tendency is given.

That is, the fingers 75A and 75B integrated vertically are supported by the finger supporter 73 at the base side thereof so as to be freely rotatable on the finger pivot 75P, and are always biased to open by the setting spring 75S. Further to the rear end portion thereof, a finger displacer 76 is attached thereto as a displacement receiving pivot 75 d.

The finger shifter 76 is constituted by a shift rod 79 rotatably connected to a slide shift cylinder 78 supported on the bed B side and by combining chain pieces 76C and 76D having a V-shape in a side view, and a collective portion of the chain pieces 76C and 76D is pin-connected to the shift rod 79 as a shift pivot 76P.

As can be understood from this configuration, in this embodiment, the approaching and separating of the vibration stopper 7 to the gun drill 5 side and the loosening and holding of the gun drill 5 by the finger unit 75 and the releasing thereof are performed by one slide displacement cylinder 78, and the operation thereof will be described below.

i) Initial state

The initial state is a stable operation state of the vibration damper 7, and the slide unit 71 is extended to the position where it projects most forward by receiving the extension of the displacement rod 79. And the finger unit 75 at the foremost end is formed by approaching the upper and lower fingers 75A and 75B to each other and loosely holding the gun drill 5, thereby achieving the vibration damping effect. At this time, the upper and lower fingers 75A and 75B are in the loosely held state against the setting spring 75S.

ii) the retreating action of the vibration-stopping device

In this operation, first, the displacement rod 79 of the slide displacement cylinder 78 is contracted. Upon receiving this operation, the upper and lower fingers 75A and 75B, which are always in an open tendency, open their tip sides in accordance with the elastic force of the setting spring 75S. When the displacement rod 79 is further contracted, the slide unit 71 is withdrawn as it is pulled away.

iii) Return action (gun drill loose hold)

This operation is performed in reverse to the retreating operation of the vibration damper 7, and the slide unit 71 first advances by the extension of the displacement rod 79. At this time, the upper and lower fingers 75A, 75B of the finger unit 75 are opened by the setting spring 75S.

Then, the slide unit 71 is pushed out to the foremost end, and then the finger displacer 76 is stopped there, and then receives further travel of the displacement lever 79, and the displacement receiving pivot 75d side is opened against the setting spring 75S by being pressed by the displacement pivot 76P. That is, the upper and lower fingers 75A, 75B are pivoted at the finger pivot 75P to close the respective fingers 75A, 75B and release the holding gun drill 5 to obtain the initial state thereof.

While the respective configurations and operations of the chain type and the slide type have been described above, the gun drill 1 of the present invention may be provided with a control panel 8 for controlling the spindle unit 2, the work holder 4, the vibration damping devices 6 and 7, and the like, as shown in fig. 1.

An example of the gun drill 1 of the present invention is configured as described above, and an operation mode of the entire apparatus will be described below with reference to fig. 11.

i) Preparation work

The preparation work is mainly setting of the workpiece W and mounting of the gun drill 5.

First, as shown in fig. 11 (a), the position of the work retainer 4 is set to an appropriate position according to the length of the work W, and as shown in fig. 11 (b), both ends of the work W are held by the chuck 42 of the work retainer 4 and the chuck 35 on the chip box 3 side.

On the other hand, in the installation of the gun drill 5, since the vibration stopper devices 6 and 7 are both freely retractable from the stable operation position in the present invention, the plurality of vibration stopper devices 6 and 7 are all in the retracted state described above

In this state, the base of the gun drill 5 on the driving side is fixed by the nut 27 for the chuck on the spindle 23 side, and the tip side is inserted into the chip box 3 and held by the drill bush 32.

In addition, in this operation, since all the vibration dampers 6 and 7 can be set in the retracted state, the setting operation of the gun drill 5 can be easily performed.

ii) setting of the vibration-damping device

After the gun drill 5 is mounted, the vibration stop means 6, 7 are actuated as described to displace the entire seat into a stable action means, holding the gun drill 5 by loosening each finger unit 65, 75.

In this case, depending on the length of the workpiece W, the vibration dampers 6 and 7 may not be operated in a part close to the spindle unit 2.

iii) perforation by gun drill and withdrawal of vibration-stopping device

Subsequently, the gun drill 5 is driven, and the tip thereof acts on the workpiece W to start the piercing action. In addition, the piercing step may be performed by rotating only the gun drill 5 to fix the workpiece W to, for example, the workpiece holder 4 of the table structure, or by rotating the workpiece W in a direction opposite to the gun drill 5.

As the punching operation progresses, the spindle unit 2 gradually moves toward the workpiece W and relatively retreats from the steady operation positions in order from the vibration dampers 6 and 7 on the side closer to the spindle unit 2, as shown in fig. 11. Thus, the main shaft unit 2 prevents the interference with the vibration stopper devices 6 and 7, and the remaining vibration stopper devices 6 and 7 remain in the free zone Z, thereby supporting the smooth rotation of the gun drill 5.

Then, near the end of the boring operation, the vibration dampers 6 and 7 which are left near the chip box 3 are also retracted, and the spindle unit 2 is moved to the near position of the chip box 3.

From this operation form, it is apparent that the entire length of the gun drill 5 can be reduced to a size that almost halves the boundary size required conventionally, resulting in stabilization of the operation.

Description of reference numerals:

1: gun drill

2: spindle unit

20: outer casing

21: stator

22: rotor

23: main shaft

24: bearing assembly

25: oil hole

26: oil supply pipe

27: screw cap (for chuck)

3: chip box

30: outer casing

31: protective seal

31 a: drill bit hole

32: drill bushing

32 a: drill bit hole

35: clamping head

4: workpiece holder

41: relative rotation unit

42: clamping head

5: gun drill

51: v-shaped groove

52: oil hole

6: vibration damping device (chain type)

60: support column

60A: cylinder support

60B: arm support

61: undulation arm

61P: arm pivot

61S: arm setting spring

61F: (undulated side) finger

62: vibration-proof guide piece

62A: guide channel

63: switch chain

63F: (switch side) finger

63P: switch chain pivot

63D: displacement passive part

63S: chain setting spring

64: vibration-proof guide piece

64A: guide channel

65: finger unit

66: displacement cylinder

66P: cylinder pivot

67: displacement rod

67E: rod tail end

67P: lever pivot

7: vibration damping device (sliding type)

70: guide rail

71: sliding unit

72: sliding block

72G: linear guide

73: finger support

74: switch guide part

75: finger unit

75A: (Upper) finger

75B: (lower) finger

75 d: displacement receiving pivot

75G: vibration-proof guide piece

75P: finger pivot

75S: setting spring

76: finger shifter

76A: upper finger shifter

76B: lower finger shifter

76C: chain sheet

76D: chain sheet

76P: displacement pivot

77: cylinder support

78: sliding displacement cylinder (as displacement means)

79: displacement rod

8: control panel

d 0: spacer

dx: spacer

B: bed

H: deep hole

M4: motor with a stator having a stator core

R2: track

R4: track

W: workpiece

Z: a free region.