WO2005113191A1

WO2005113191A1 - Revolving type clamp

Info

Publication number: WO2005113191A1
Application number: PCT/JP2005/007320
Authority: WO
Inventors: Keitaro Yonezawa; Hideaki Yokota; Yosuke Haruna
Original assignee: Kosmek Ltd.
Priority date: 2004-05-21
Filing date: 2005-04-15
Publication date: 2005-12-01
Also published as: JP2005329525A; TW200609076A

Abstract

A cylindrical housing (2) is provided with a cylinder hole (17) and a rod hole (18) in this order with the holes facing up. A piston (19) inserted in the cylinder hole (17) is connected to a clamp rod (5). Disposed on the upper side of the piston (19) is a lock chamber (20) for supplying/discharging pressure oil. An annular flow channel (23) is formed between the peripheral wall of the rod hole (18) and the outer peripheral surface of the clamp rod (5). A supply/discharge port (24) communicates with the upper portion of the annular flow channel (23). A throttle fitting hole (41) is concentrically disposed in the lower portion of the peripheral wall of the rod hole (18). A fitting section (42) adapted to be fitted in the fitting hole (41) in the terminal period of revolutionary rise of the clamp rod (5) is disposed in the upper portion of the piston (19). Thereby, the pressure oil in the lock chamber (20) is discharged to the supply/discharge port (24) through an annular throttle gap (G) formed between the fitting hole (41) and the fitting section (42).

Description

Specification

Swivel clamp

Technical field

The present invention relates to a clamp of a type in which a clamp rod is turned to press a work, and more specifically, the clamp rod is movable in an axial direction and rotatable around the axial center in a cylindrical housing. And an arm is fixed to the upper part of the clamp rod.

Background art

[0002] As this type of swiveling clamp, conventionally, as shown in Patent Document 1 (US Pat. No. 5,820,118), there is one configured as follows.

(4) A cylinder hole and a rod hole are sequentially provided upward in the housing. The clamp rod includes a piston inserted into the cylinder hole and a piston rod inserted into the rod hole. A vertically long annular flow path is formed between the peripheral wall of the aperture and the outer peripheral surface of the piston rod. An engagement ball is fitted into a guide groove formed on the outer peripheral surface of the piston rod, and the ball is supported on the peripheral wall of the rod hole.

[0003] During the release operation of the clamp, the pressure oil in the lock chamber formed above the piston is discharged to the outside through the annular flow path and the guide groove, and the release oil formed below the piston is released. Supply pressurized oil to the chamber. As a result, the clamp rod first rises along the rectilinear groove of the guide groove, and subsequently rises while releasing and turning along the spiral groove of the guide groove. Then, the piston rod of the rotating clamp rod is received by the upper end wall of the nozing, thereby stopping the clamp rod.

Patent document 1: U.S. Pat.No. 5,820,118

Disclosure of the invention

Problems to be solved by the invention

[0004] Recently, in order to shorten the machining cycle of the work, it is required to shorten the release operation time of the above-mentioned revolving clamp. However, in the above prior art, There are the following problems:

If the release speed of the clamp rod is increased by increasing the supply and discharge of hydraulic oil during the release operation to shorten the release operation time, the piston rod collides with the upper end wall of the housing at a high speed when the release is stopped. I do. The impact may cause plastic deformation of the guide grooves, balls, and the like provided on the piston rod, which may lower the turning accuracy of the clamp rod. This adverse effect becomes a serious problem because the larger the arm fixed to the upper part of the clamp rod becomes, the larger the inertia force at the time of collision becomes.

[0005] In order to solve the above-mentioned problems, the present inventors considered making the following changes to the above-mentioned prior art prior to the present invention.

The upper end opening of the guide groove is closed to prevent the pressure oil in the lock chamber from being discharged outside through the guide groove during the release operation. Further, the outer peripheral surface of the piston rod is fitted into the peripheral wall of the rod hole with an annular throttle gap. As a result, the pressurized oil in the lock chamber is discharged to the outside through the above-described throttle gap at the time of the release operation. Gently abuts the top wall of the As a result, the impact force when the release is stopped is reduced, and the turning accuracy of the clamp rod can be maintained.

[0006] However, in the above-described prior invention example, since the throttle gap is formed in the entire vertical region between the peripheral wall of the rod hole and the outer peripheral surface of the piston rod, the above-described throttle operation is formed in the entire region of the release operation. The speed of the clamp rod becomes slow, and the release operation time cannot be shortened.

SUMMARY OF THE INVENTION An object of the present invention is to achieve both a reduction in the release operation time and a maintenance of the turning accuracy in a turning clamp.

Means and effects for solving the problem

[0007] In order to achieve the above object, the present invention provides, as shown in FIGS. 1A to 3B, FIGS. 4A and 4B, FIGS. 5A and 5B, or FIG. Configured.

A clamp rod (5) is supported by a cylindrical housing (2) so as to be movable in the axial direction and rotatable around the axial center, and an arm (6) is provided at the tip of the clamp rod (5). The housing (2) is provided with a cylinder hole (17) and a rod hole (18) in the order of the tip. The piston (19) inserted into the cylinder hole (17) is connected to the clamp rod (5). Tip of that piston (19) On the side there is a lock chamber (20) to which pressure fluid is supplied and discharged. An annular flow path (23) is formed between the peripheral wall of the rod hole (18) and the outer peripheral surface of the clamp rod (5), and a pressure fluid supply / discharge roller (24) is provided in the annular flow path (23). Communicate. At the time of the release operation, by releasing the pressure fluid in the lock chamber (20) to the supply / drain port (24) through the annular flow path (23), the release drive means (R) First, the clamp rod (5) is linearly moved in the direction of the distal end, and subsequently, the clamp rod (5) is moved in the direction of the distal end while the release mechanism is turned by the turning mechanism. An aperture (41) for constriction is provided concentrically on the peripheral wall of the rod hole (18). At the end of the release swiveling movement, the fitting part (42) fitted into the fitting hole (41) with an annular throttle gap (G) is inserted into the fitting rod (5) and the piston (19). Provided in at least one of them. At the end of the release swing movement, the pressure fluid in the lock chamber (20) is discharged to the supply / discharge port (24) via the annular throttle gap (G).

[0008] The present invention has the following effects.

At the time of the release operation, the pressure fluid in the lock chamber is quickly discharged to the supply / discharge port through the annular flow path until immediately before the end of the release swing movement. The rod moves at high speed. On the other hand, when the fitting portion starts to fit into the fitting hole while rotating at the end of the release swing movement, the pressure fluid in the lock chamber is supplied through the annular throttle gap. Start to be discharged to the outlet. Therefore, a predetermined back pressure is maintained in the mouth chamber by the flow resistance applied to the pressure fluid passing through the throttle gap, and the moving speed of the clamp rod is rapidly reduced. Therefore, the clamp rod (and the arm) stops slowly.

[0009] As described above, the clamp rod is moved at high speed from the initial stage of the release operation to immediately before the end of the release swing movement, and the clamp rod is decelerated at the end of the release swing movement, so that the release operation time is reduced. it can. The force of the clamp rod (and arm) can be gently stopped by decelerating the clamp rod at the end of the release swing movement, thereby preventing the swing mechanism such as the guide groove and the engaging ball from being damaged. The turning accuracy can be maintained in a good state.

As described above, according to the present invention, both the reduction of the release operation time and the maintenance of the turning accuracy can be achieved. [0010] In the present invention, it is preferable that the following structure be prepared.

For example, as shown in FIGS.1A to 3B (or FIG. 6), the outer diameter (D1) of the piston (19), the outer diameter (D2) of the fitting part (42), and the rod The outer diameter (D3) of the clamp rod (5) in the hole (18) is set to a smaller value in order. Then, the supply / discharge roller (24) is opened at the leading end of the rod hole (18), and the fitting hole (41) is fitted at the base end of the peripheral wall of the rod hole (18). Provide.

According to the present invention, a relatively large gap can be secured between the distal end of the rod hole and the outer peripheral surface of the clamp rod. For this reason, even if the clamp rod is inclined at the end of the release operation due to the inertial force or the like acting on the arm due to the presence of the gap between the fitting portions of the support portions of the clamp rod, the clamp rod remains in the supply / drain port. Can be prevented from being closed. As a result, it is possible to prevent the clamp rod from becoming abnormally slow at the end of the release swing movement.

In the present invention, for example, as shown in FIG. 4A or FIG. 5A, a distal direction of the piston (19) is provided between a distal end wall of the lock chamber (20) and the piston (19). A spacer (51) may be interposed to restrict movement to ,.

In this case, the turning angle of the clamp rod can be set to a desired value by adjusting the thickness of the spacer.

In the case where the spacer is interposed, for example, as shown in FIG. 4A, the annularly formed spacer (51) is mounted on the distal end wall of the lock chamber (20), The fitting hole (41) for the throttle may be provided concentrically on the inner peripheral surface of the spacer (51).

In the case where the spacer is interposed, the spacer (51) is mounted on at least one of the clamp rod (5) and the piston (19) as shown in FIG. 5A, for example. And

The spacer (51) may be provided with the fitting portion (42).

Brief Description of Drawings

FIG. 1A shows a first embodiment of the present invention, and is an elevational cross-sectional view of a locked state of a revolving clamp, and is a view corresponding to a view taken along line 1A-1A in FIG. 1B. It is. FIG. 1B is a plan view of FIG. 1A described above.

[FIG. 2] FIG. 2A shows a state in which the above-mentioned clamp is being switched to the above-mentioned state in which the above-mentioned lock state force is also released. FIG. 2 is a view similar to FIG. 1A above. FIG. 2B is a plan view of FIG. 2A above.

FIG. 3A is a view similar to FIG. 1A, showing a released state of the clamp. FIG. 3B is a plan view of FIG. 3A described above.

FIG. 4A is a view similar to FIG. 3A, showing a first modification of the clamp. FIG. 4B is a plan view of FIG. 4A described above.

FIG. 5A is a view similar to FIG. 4A, showing a second modification of the clamp. FIG. 5B is a plan view of FIG. 5A described above.

FIG. 6 shows a clamp according to a second embodiment of the present invention, and is a view similar to FIG. 3A described above.

FIG. 7 is a partial view showing a modification of the clamp of the second embodiment.

Explanation of symbols

[0015] 2: Nosing, 5: Clamp rod, 6: Arm, 17: Cylinder hole, 18: Rod hole, 19: Bistone, 20: Lock chamber, 23: Annular flow path, 24: Supply / drain 41: fitting hole, 42: fitting part, 51: spacer, D1: outside diameter of piston 19, D2: outside diameter of fitting part 42, D3: port hole 18 Outer diameter of the clamp rod 5 inside, G: Restriction gap, R: Release drive means. BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1A to FIG. 3B show a first embodiment of the present invention. First, the overall structure of the revolving clamp will be described with reference to FIGS. 1A and 1B. FIG. 1A is an elevational sectional view of the locked state of the clamp. FIG. 1B is a plan view of FIG. 1A described above.

The flange 2 a of the cylindrical housing 2 of the clamp 1 is fixed to the work pallet P with a plurality of bolts 3. The clamp rod 5 is inserted into the cylindrical hole 4 of the housing 2. An arm 6 projecting outward in the radial direction is fixed to a predetermined turning position by a detent pin 7 and a nut 8 at the upper end (tip) of the clamp rod 5. The push bolt 9 fixed to the projecting portion of the arm 6 presses the work W against the upper surface of the work pallet P! /, The through hole 10 formed in the upper end wall 2b of the housing 2, and The upper sliding portion 11 of the clamp rod 5 is vertically movable and is hermetically supported. Also, the lower end wall of the housing 2 The lower sliding portion 12 of the clamp rod 5 is vertically movably supported by a support cylinder 13 which constitutes a part of 2c.

Here, the means for driving the clamp rod 5 is of a hydraulic double-acting type as described below.

The cylindrical hole 4 of the housing 2 includes a cylinder hole 17 and a rod hole 18 formed substantially concentrically and sequentially upward. A piston 19 inserted in the cylinder hole 17 in a hermetically sealed manner is formed integrally with the clamp rod 5. A lock chamber 20 is provided above the piston 19, and a release chamber 21 is provided below the piston 19.

An annular flow path 23 is formed between the peripheral wall of the rod hole 18 and the outer peripheral surface of the upper sliding portion 11 of the clamp rod 5. A lock supply / discharge roller 24 communicates with the upper half of the annular path 23.

Further, the release chamber 21 is communicated with a release supply / discharge roller 27 through a vertical hole 26 formed in the body wall 2d of the housing 2. That is, the release drive means R is constituted by the pressure oil supplied from the release supply / discharge unit 27 to the release chamber 21 and the piston 19.

A turning mechanism is provided between the lower sliding portion 12 of the clamp rod 5 and the upper portion of the support tube 13. The turning mechanism is configured as follows.

A plurality of guide grooves 31 are provided on the outer peripheral surface of the lower sliding portion 12 at equal intervals in the circumferential direction. Each of the above-mentioned guide grooves 31 is configured by connecting a spiral turning groove 32 and a straight-moving groove 33 extending in the vertical direction upward. An engaging ball 34 is fitted into each of the guide grooves 31 described above. Each engagement ball 34 is rotatably supported by a lateral hole 35 provided in the upper part of the support cylinder 13. A sleeve 36 is fitted around the plurality of engagement balls 34 so as to be rotatable around the axis.

The outer peripheral wall of the support cylinder 13 is prevented from rotating by the body wall 2d of the housing 2 via a positioning pin 38 extending in the vertical direction. The support cylinder 13 is fixed to the body wall 2d by a ring member 39.

[0020] Further, means for reducing the turning movement of the clamp rod 5 is provided. That is, a fitting hole 41 for constriction is provided concentrically in the lower half of the peripheral wall of the rod hole 18. A fitting portion 42 to be fitted into the fitting hole 41 is provided below the upper sliding portion 11 of the clamp rod 5. Can be As shown in FIG. 3A to be described later, when the clamp 1 is released, an annular throttle gap G is formed between the fitting hole 41 and the fitting portion 42 in the vertical direction.

The outer diameter dimension D1 of the piston 19, the outer diameter dimension D2 of the fitting portion 42, and the outer diameter dimension D3 of the upper sliding portion 11 are sequentially set to smaller values. You.

The operation of the pivotable clamp 1 having the above configuration will be described with reference to FIGS. 1A and 1B and FIGS. 2A to 3B. FIG. 2A shows a deceleration start state in which the clamp 1 in FIG. 1A is being switched to the release state in the lock state force in FIG. 1A. FIG. 2B is a plan view of FIG. 2A described above. FIG. 3A shows the released state of the clamp. FIG. 3B is a plan view of FIG. 3A described above.

In the first embodiment, the clamp rod 5 and the arm 6 are moved from the lock pivot position X in FIGS. 1A and 1B to the deceleration start position Y in FIGS. 2A and 2B, as shown in FIGS. 3A and 3B. The total turning angle まで up to the release turning position Z is set to about 90 degrees.

In the locked state shown in FIGS. 1A and 1B, the pressurized oil is discharged from the release chamber 21 and is supplied to the lock chamber 20, whereby the clamp rod 5 is moved to the lock pivot position. The arm 6 presses the work W against the work pallet P and moves down. When switching the clamp in the locked state to the release state, the lock supply / discharge port 24 is communicated with an oil tank (not shown), and the pressure oil of a hydraulic pressure source (not shown) is supplied to the release supply / discharge port 27 and the release supply / discharge port 27. Is supplied to the release chamber 21 through the vertical hole 26.

Then, the pressure oil in the lock chamber 20 is quickly discharged to the lock supply / discharge port 24 through the annular flow path 23. Thereby, first, the piston 19 raises the clamp rod 5 (and the arm 6) straight and high-speed straight along the rectilinear groove 33. Subsequently, the clamp rod 5 is moved upward by the pivot groove 33. Ascending while turning at high speed in a counterclockwise direction in plan view along.

Then, as shown in FIGS. 2A and 2B, when the clamp rod 5 (and the arm 6) turns in a high-speed turning angle α (here, about 70 degrees), the fitting portion 42 begins to fit into the fitting hole 41. Then, the pressure oil in the lock chamber 20 starts to be discharged to the lock supply / discharge port 24 via the annular throttle gap G (see FIG. 3), and is applied to the pressure oil passing through the throttle gap G. A predetermined back pressure is maintained in the lock chamber 20 by the flow resistance It is.

As a result, the swing rising speed of the clamp rod 5 starts to be rapidly reduced. Then, as the clamp rod 5 pivots and rises, the vertical fitting length of the fitting portion 42 to the fitting hole 41 increases, and the flow resistance due to the throttle gap G also increases. Become. For this reason, the clamp rod 5 (and the arm 6) gradually rotates upward in the area of the deceleration rotation angle j8 (here, about 20 degrees), and cuts into the release rotation position Z in FIGS. 3A and 3B. Be replaced.

As described above, at the end of the release swing movement, the speed of the clamp rod 5 (and the arm 6) is reduced, and the piston 19 comes into gentle contact with the upper end wall 2b of the housing 2. For this reason, the impact force acting on the above-mentioned swivel groove 32, engagement ball 34, detent pin 7, positioning pin 38 and the like is reduced.

As a result, the turning mechanism such as the turning groove 32 and the engaging ball 34 can be prevented from being plastically deformed or damaged, the turning angle can be maintained in a good state, and the life of the clamp 1 can be prolonged. Further, since the impact is reduced, noise and vibration are also reduced, so that the screw fitting of the nut 8 for fixing the arm 6 to the clamp rod 5 can be prevented from being loosened, and the work pallet P ゃヮW will not be affected.

Further, the lock supply / discharge roller 24 is opened at the upper end of the rod hole 18, and the fitting hole 41 for the throttle is provided at the lower end of the rod hole 18. A relatively large gap can be ensured between the upper end of 18 and the outer peripheral surface of the clamp rod 5. For this reason, the existence of the fitting gap of the support hole (the through hole 10) of the upper sliding portion 11 and the fitting gap of the support hole 13a of the lower sliding portion 12 makes the arm Even when the clamp rod 5 is inclined at the end of the release operation due to inertial force or the like acting on 6, it is possible to prevent the clamp rod 5 from closing the opening of the lock supply / discharge roller 24. As a result, abnormally low speed of the clamp rod 5 can be prevented at the end of the release swing movement.

When the clamp 1 in the released state shown in FIGS. 3A and 3B is switched to the locked state, the pressurized oil in the release chamber 21 is discharged from the release supply / discharge port 27 and the lock supply / discharge port is released. Supply the pressurized oil to 24. Then, the pressure oil of the lock supply / discharge unit 24 is Acting on the upper surface of the fitting portion 42 and the upper surface of the piston 19, the piston 19 is lowered. Accordingly, the clamp rod 5 first descends while pivoting clockwise in plan view along the pivot groove 32 (see FIGS. 2A and 2B), and subsequently, the rectilinear groove 33 It moves straight down along the line and switches to the locked state (see FIGS. 1A and 1B).

FIGS. 4A and 4B show a first modification of the revolving clamp of the first embodiment.

FIG. 4A shows a released state, and is similar to FIG. 3A described above. FIG. 4B is a plan view of FIG. 4A described above. In the first modified example (and a second modified example and a second embodiment to be described later), members similar to those of the above-described first embodiment will be described in principle with the same reference numerals.

[0028] The first modified example differs from the first embodiment in the following points.

On the lower surface of the upper end wall of the lock chamber 20, an annular spacer 51 for restricting upward movement of the piston 19 is mounted by a plurality of bolts 52. The annular throttle gap G is provided between the fitting hole 41 formed by the inner peripheral surface of the spacer 51 and the fitting portion 42. That is, in the first modified example, the inner peripheral surface of the annular spacer 51 forms a part of the rod hole 18.

By interposing the spacer 51, the high-speed turning angle ex is set to about 50 degrees, the deceleration turning angle β is set to about 20 degrees, and the total turning angle Θ is set to about 20 degrees.

It is set to 70 degrees.

In addition, the mounting means of the spacer 51 may be a retaining ring or the like instead of the illustrated bolt 52. In addition, press fitting, force crimping, or the like can be used as a mounting means of the spacer 51.

FIGS. 5A and 5B show a second modification of the above-mentioned swivel type clamp. FIG. 5A is a view similar to FIG. 4B of the first modification. FIG. 5A is a plan view of FIG. 5A described above. This second modification differs from the first modification in the following points.

The large-diameter portion 55 of the cylindrical spacer 51 is placed on the upper surface of the piston 19, and the small-diameter portion 56 is fitted over the clamp rod 5, and the spacer 51 is pulled out by a retaining ring 57. It has been stopped. The fitting portion 42 constituted by the small diameter portion 56 and the opening The annular throttle gap G is formed between the fitting hole 41 provided in the lower part of the pad hole 18 and the annular gap G described above. Alternatively, it may be fixed to the piston 19 or the clamp rod 5 by press fitting or caulking.

FIG. 6 shows a clamp according to a second embodiment of the present invention, and is a view similar to FIG. 3A of the first embodiment.

The second embodiment differs from the first embodiment in the following points.

The revolving clamp 1 is configured as a panel release type with a hydraulic lock. That is, the clamp rod 5 is projected upward from the button 19. Similar to the first embodiment, the clamp rod 5 is driven downward by pressurized oil in a lock chamber 20 formed above the piston 19, and is attached to a release chamber 21 below the piston 19. The return panel 60 is driven to move upward. The return panel 60 constitutes the release driving means R.

[0031] Further, the rod hole 18 is formed to be longer in the vertical direction than in the above-mentioned FIG. 3A. Then, the plurality of guide grooves 31 are formed below the clamp rod 5. The engaging balls 34 fitted in the respective guide grooves 31 are supported by the body wall 2d of the housing 2. Note that the screwing direction of the turning groove 32 of the guide groove 31 is formed in a direction opposite to that of the first embodiment.

At the lower end of the rod hole 18 is formed the fitting hole 41 for drawing, and at the lower end of the clamp rod 5, the fitting portion 42 is formed. The annular throttle gap G is formed between the fitting hole 41 and the fitting portion 42. The lock supply / discharge roller 24 is opened at the upper end of the rod hole 18.

The clamp 1 of the second embodiment operates in the same manner as the first embodiment.

FIG. 7 is a partial view showing a modification of the clamp of the second embodiment. This modified example is different from the second embodiment of FIG. 6 in the following point.

The lower portion of the rod hole 18 is slightly enlarged in diameter, and a fitting hole for the above-described diaphragm is formed in the enlarged diameter portion.

41 is formed. Correspondingly, the diameter of the fitting portion 42 is also enlarged.

Each of the above embodiments and modifications can be modified as follows. The fitting structure between the fitting hole 41 and the fitting portion 42 described above is not limited to the illustrated straight fitting, and at least a part of the fitting region may be formed by taper fitting. Each of the turning angles θ · α · j8 described above can be set to various desired values other than those illustrated.

The structure of the first embodiment (the force of FIG. 1A and FIG. 3B) may be configured as a panel release type with a hydraulic lock, similarly to the structure of the second embodiment (FIG. 6). Further, the structure of the second embodiment (FIG. 6) may be configured as a hydraulic lock and hydraulic release type, similarly to the structure of the first embodiment (the force of FIG. 1A is also FIG. 3B).

The revolving clamp 1 can be arranged diagonally or upside down, instead of the vertical arrangement shown above.

The pressure fluid may be a gas such as another type of liquid or compressed air instead of the pressure oil.

Claims

The scope of the claims

[1] A clamp rod (5) is supported on a cylindrical housing (2) so as to be movable in the axial direction and rotatable around the axis, and an arm (6) is attached to the tip of the clamp rod (5). The swivel clamp provided

A cylinder hole (17) and a rod hole (18) are sequentially provided in the housing (2) in the distal direction, and a piston (19) inserted into the cylinder hole (17) is connected to the clamp rod (5). A lock chamber (20) for supplying and discharging a pressurized fluid is provided at the tip side of the piston (19), and an annular flow path is provided between the peripheral wall of the rod hole (18) and the outer peripheral surface of the clamp rod (5). (23) is formed, and a supply / discharge port (24) for pressurized fluid is communicated with the annular flow path (23),

During the release operation, the release drive means (R) first discharges the pressure fluid in the lock chamber (20) to the supply / discharge roller (24) through the annular flow path (23). The clamp rod (5) is linearly moved in the direction of the above-mentioned tip, and subsequently, the clamp rod (5) is moved in the direction of the above-mentioned tip while the release mechanism is rotated by the turning mechanism, and the rod hole (18) is formed. A constriction fitting hole (41) is provided concentrically on the peripheral wall of (3), and is fitted into the fitting hole (41) with an annular constriction gap (G) at the end of the release turning movement. A fitting portion (42) is provided on at least one of the clamp rod (5) and the piston (19). At the end of the release swing movement, the pressure fluid in the lock chamber (20) is supplied to the lock chamber (20). Discharging to the supply / discharge roller (24) through the annular throttle gap (G). Swivel clamp.

[2] The swivel clamp according to claim 1,

The outer diameter (D1) of the piston (19), the outer diameter (D2) of the fitting portion (42), and the outer diameter of the clamp rod (5) in the hole (18). The diameter (D3) is set to a smaller value in order, and the supply / discharge roller (24) is opened at the distal end of the rod hole (18), and the base end of the above-mentioned peripheral wall of the rod hole (18) is set. A swiveling clamp, wherein the fitting hole (41) is provided in a portion.

[3] The swivel clamp according to claim 1 or 2,

A spacer (51) for restricting the movement of the piston (19) toward the distal end is interposed between the distal end wall of the lock chamber (20) and the piston (19). Swiveling clan H.

[4] The swivel clamp according to claim 3,

The annular spacer (51) is mounted on the distal end wall of the lock chamber (20), and the aperture fitting hole (41) is formed on the inner peripheral surface of the spacer (51). ) Is provided concentrically.

[5] The pivotable clamp according to claim 3,

At least one of the clamp rod (5) and the piston (19) is fitted with the spacer (51), and the spacer (51) is provided with the fitting portion (42). Features a swiveling clamp.