JP2879460B2 - Hydraulic clamp - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION << Industrial application field >> The present invention relates to a hydraulic clamp for pressing and fixing an object to be fixed to a fixed member such as a fixing stand of a machine tool. The present invention relates to a moving type hydraulic clamp.

<< Basic Basic Structure >> The hydraulic clamp according to the present invention relates to a hydraulic clamp having a basic structure as follows.

For example, JP-A-1-123708 (Japanese Patent Application No. 62-282665, hereinafter referred to as Conventional Example 1) and Japanese Patent Application No. 62-335141 (hereinafter referred to as Prior Invention Example 2) proposed by the present inventor, Alternatively, as shown in FIGS. 1 to 8 corresponding to the embodiment of the present invention, the clamp hydraulic oil chamber 15 and the hydraulic piston 12 are provided between one end side and the other end side of the cylinder body 5 of the hydraulic cylinder 4. And a clamp tool 27 are provided in this order. The clamp tool 27 includes a clamp tool output portion 29 provided at least on the other end side and a clampable advance position X and a non-clamp retractable position Y at different distances from the axis A of the hydraulic cylinder 4.
At the clamp movable advance position X, it is configured to be able to advance and retreat along the axis A of the hydraulic cylinder 4 between an unclamping position U on one end and a clamping position C on the other end. The retracting means 30 presses the clamp member 27 toward the non-clampable retreat position Y, and the clamp member 27 can be pushed out toward the clampable advance position X side by the advance inclination cam 31. After being pushed from the non-clampable retreat position Y to the clampable advance position X at 31, it is configured to be propelled from the unclamped position U to the clamped position C by the hydraulic pressure of the hydraulic piston 12.

<< Prior Art >> In the above basic structure, Conventional Example 1 is for driving the clamp after the clamp tool is reduced in diameter, and Prior Art Example 2 is for driving the clamp tool after expanding the diameter of the clamp tool. However, in either case, the extension inclination cam is only elastically pressed against the clamp with a compression spring, and the expansion and contraction movement of the clamp from the non-clampable retreat position to the clampable advance position is also performed by the hydraulic piston. It was configured to be performed by hydraulic drive force.

<< Problems to be Solved by the Invention >> By the way, the expansion and contraction movement of the expansion and contraction movement type clamp tool cannot be smoothly performed when foreign matter such as dust enters or rusts or insufficient lubrication occurs.

In the above prior art, since two operations, ie, the operation of expanding and contracting the clamp and the operation of driving the clamp, are performed continuously by the continuous operation of the hydraulic piston, the clamp is in an expanded state (or reduced state) or There is a possibility that the clamp drive may be performed with the half-open state. If the clamp is driven while the diameter is increased (or reduced), a clamping error occurs. In addition, when the clamp is driven in the half-open state, the contact transmission portion between the clamp tool output portion and the passive member for clamping is easily damaged, so that the life of the hydraulic clamp is shortened.

SUMMARY OF THE INVENTION It is an object of the present invention to prevent a clamping error and to keep the life of a hydraulic clamp good for a long period of time.

<< Means for Solving the Problems >> In order to achieve the above object, the present invention provides, in the above-mentioned basic structure, for example, as shown in FIG. 1 to FIG. 8, or FIG. 9 or FIG. It features the following improvements.

(Invention of Claim 1) A fluid cylinder for cam advancement is provided at the other end of the cylinder body 5.
45, and the movable side member 46 (49) of the fluid pressure cylinder 45 is linked to the advance tilt cam 31. The advance movable cam 46 (49)
31 is configured such that it can be driven to advance from the non-clampable retreat position Y to the clampable advance position X.

The movable member of the fluid pressure cylinder 45 may be a piston 46 or a piston return spring 49.

(Invention of Claim 2) The following structure is added to the structure of the above-mentioned claim 1.

The cam advance fluid pressure cylinder 45 has a fluid pressure working chamber 47 formed at one end of the fluid pressure piston 46 and a return spring chamber 48 formed at the other end thereof. In contrast to the backward drive of the other end 46, the advance inclined cam 31 is driven to advance to one end by the elastic force of the return spring 49 in the return spring chamber 48.

(Invention of Claim 3) In the configuration of Claim 1 or 2, the following configuration is added.

Detecting means for detecting the advance / retreat position of the fluid pressure piston 46
The output signal of the detection means 64 is linked to the input of the control means 75, and the control means 75 detects the state in which the fluid pressure piston 46 has completely advanced to one end side. Based on this, the configuration is such that the supply of pressure oil from the hydraulic supply / discharge means 18 connected to the clamp hydraulic oil chamber 15 of the hydraulic cylinder 4 is permitted.

Further, the following configuration is added to the configuration of each of the above-described inventions.

The clamp tool 27 is constituted by a plurality of clamp claws 27a arranged in a ring, and a plurality of circumferential grooves 35 for guiding the expansion and contraction are formed over the plurality of clamp claws 27a arranged in a ring. The expansion / contraction movement guide ring 34 was slidably guided in the radial direction.

 Further, in each of the above configurations, the following configuration is added.

The retracting means 30 enables the clamp member 27 to move to the non-clampable retreat position Y away from the axis A of the hydraulic cylinder 4 by the retracting means 30, and the clamp member 27 is moved to the inclined cam for advance.
At 31, the diameter of the hydraulic cylinder 4 can be reduced and guided to the clampable advance position X which is close to the axis A of the hydraulic cylinder 4. In this configuration, one end of the passive member for clamping 6 is fixed to the fixed member 1, and the passive portion 25 on the other end of the passive member for clamping 6 is fixed.
The cylinder body 5 is configured to be fitted to and detached from the outside.

<< Operation >> The present invention operates as follows.

(Invention of Claim 1) The hydraulic clamp 3 is, for example, as shown in FIG.
The state is switched from the unclamped state in (a) to the clamped state in (c) in the following procedure.

(A) In the unclamped state shown in FIG.
The hydraulic oil is discharged from 15, the hydraulic piston 12 is unclamped to one end, and the hydraulic piston 46, which is the movable member of the cam advance hydraulic cylinder 45, is driven backward to the other end, The clamp member 27 is switched to the non-clampable retreat position Y by the retreat means 30.

Next, from the above unclamped state, the fluid pressure piston 46 as the cylinder movable side member is driven to advance to one end side. Then, as shown in FIG.
Is driven to one end via the fluid pressure piston 46 (or the piston return spring 49) to switch the clamp 27 to the clampable advance position Y.

Thereafter, pressurized oil is supplied to the clamp working oil chamber 15. Then, as shown in FIG. 3C, the hydraulic piston 12 is driven to be clamped to the other end, and the clamp 27 is switched from the unclamping position U to the clamping position C in FIG.

As described above, the clamp device 27 can perform two switching operations, that is, the switching operation from the unclampable retreat position Y to the clampable advance position X and the switching operation from the unclamping position U to the clamping position C, respectively. After confirming that it has been switched to the clampable advance position X, the hydraulic piston
With 12 it becomes possible to drive hydraulically. As a result, the clamp 27 can be prevented from being hydraulically driven while the diameter of the non-clampable retreat position Y is expanded (or reduced in diameter), and a clamping error can be prevented. In addition, since the clamp 27 can be prevented from being hydraulically driven in the half-open state, damage to the contact transmission portion with the passive member for clamping 6 can be prevented, and the life of the hydraulic clamp 3 can be kept good for a long period of time.

(Invention of Claim 2) Since the clamp member 27 is strongly switched from the non-clampable retreat position Y to the clampable advance position X by the elastic pressure of the piston return spring 49, the switching time can be shortened and the switching operation can be performed. It is certain.

(Invention of Claim 3) The clamp 27 can automatically detect the switching from the non-clampable retreat position Y to the clampable advance position and can be sequentially driven, so that the axis A of the hydraulic cylinder 4 and the passive member for clamping are provided. An error occurs in the setting with the axis of 6 and the like, and the clamp member 27 is moved to the passive portion 25 of the passive member 6 for clamping.
In this case, the hydraulic drive in the case of a partial collision can be reliably avoided. For this reason, the life of the hydraulic clamp 3 can be more favorably maintained.

<< Effects of the Invention >> The present invention has the following effects because it is configured and operates as described above.

(Invention of Claim 1) Since the clamping device can perform two switching operations, namely, a switching operation from the non-clampable retreat position to the clampable advance position and a switching operation from the unclamping position to the clamp position, the clamp member can be advanced. After it is confirmed that the position has been switched to the position, it is possible to hydraulically drive with the hydraulic piston. As a result, the clamp device can be prevented from being hydraulically driven in the expanded state (or the reduced diameter state) of the non-clampable retreat position, and a clamping error can be prevented. In addition, since the clamp device can be prevented from being hydraulically driven in the half-open state, damage to the contact transmission portion with the passive member for clamping can be prevented, and the life of the hydraulic clamp can be kept good for a long period of time.

(Invention of Claim 2) Since the clamp tool is strongly switched from the non-clampable retreat position to the clampable advance position by the elastic pressure of the piston return spring, the switching time is short, and the switching operation is reliable.

(Invention of Claim 3) Since the clamp device can automatically detect the switching from the unclampable retreat position to the clampable advance position and can sequentially drive the clamp device, it is possible to hydraulically drive the clamp device in a one-sided state. Can be prevented. For this reason, the life of the hydraulic clamp can be further improved.

<< Example >> Hereinafter, an example of the present invention will be described with reference to the drawings.

(First Embodiment) FIGS. 1 to 8 show a first embodiment.

In the overall view of FIG. 2, a fixing base 1 as a fixing side member is shown.
Is fixed via a hydraulic clamp 3 to the upper surface of the device. The hydraulic clamp 3 is connected to one end (the lower end in the figure) of the cylinder body 5 of the hydraulic cylinder 4 and the fixed base 1 by the hydraulic pressure of the hydraulic cylinder 4 via a clamp rod 6 which is a passive member for clamping. The fixed object 2 is pressed and fixed in between. A fastening through hole 7 is formed in the fixed object 2 substantially coaxially with the axis A of the hydraulic cylinder 4.
The clamp rod 6 is screwed and fixed to the fixed base 1 with a leg screw portion 6a on one end side (the lower end side in the figure). The cylinder body 5 is mounted on the upper surface of the fixed object 2 with a plurality of bolts 8.

Then, at the time of the clamping operation, first, the fixed object 2 and the cylinder body 5 are externally fitted to the clamp rod 6 from above by a fastening operation device (not shown), and then a clamp 27 described later is attached to the clamp rod 6. Then, a pulling force is applied to the clamp rod 6 by the hydraulic pressure of the hydraulic cylinder 4, and the object 2 is pressed and fixed to the upper surface of the fixed base 1 by a downward reaction force acting on the cylinder body 5. .

The structure of the hydraulic clamp 3 will be described with reference to FIG. 1 (a), (b) and (c) in FIG. 1 show an unclamped state, a switching transient state, and a clamped state, respectively.

First, the hydraulic cylinder 4 will be described.
The cylinder body 5 is of a hydraulic drive / pneumatic pressure return type. The cylinder body 5 is composed of a cylinder part 9 and a lid plate 10 screwed and fixed to the upper part of the cylinder part 9 in an airtight manner. A piston 12 is inserted into the lower portion of the cylinder portion 9 so as to be slidable in an oil-tight manner in a vertical direction. A guide rod 13 projects from the lower surface of the piston 12. These piston 12 and guide rod 13
, The rod insertion hole 14 is penetrated substantially coaxially with the axis A of the hydraulic cylinder 4. A clamp hydraulic oil chamber 15 is formed below the piston 12. Clamp hydraulic chamber 15
As shown in FIG. 2, the hydraulic oil supply / discharge port 16 communicates with an electromagnetic hydraulic oil supply / discharge valve 18, a supply / discharge oil passage 19, and a hydraulic oil supply / discharge means. It is supplied through a hydraulic hose 20 and a connection base 21 in order. The oil supply / drain passage 19 is provided with a pressure switch 22 for detecting clamp completion.

The clamp rod 6, which is a passive member for clamping, has a passive part 25 formed above an insertion part 24 inserted into the cylinder body 5.

Next, means for engaging or disengaging the clamp 27 with the passive portion 25 will be described with reference to FIG. 1A and FIGS. 3 to 8.

The clamp 27 has a piston
The evacuation cam 31 is mounted on the upper surface of the evaporator 12 and is resiliently pressed by the evacuation means 30 toward the diameter-expanding side.

The clamp 27 described above is a clamp claw 27 divided into three parts.
a, 27, 27a, and a rod insertion passage D extending in the vertical direction is formed in the inner peripheral surface thereof. Each clamp claw 27a is expanded / reduced in the radial direction of the rod insertion passage D by the expansion / contraction movement guide means 33.
It is configured to be freely displaceable. That is, the expansion / contraction movement guide ring 34 is disposed on the peripheral edge of the upper surface of the piston 12. A circumferential groove 35 extending and extending in the circumferential direction is formed in the lower part of the outer circumference of each clamp claw 27a, and the circumferential groove 35 for guide is slidably fitted to the inner peripheral edge of the guide ring 34 in the radial direction. You.

The evacuation means 30 is as follows. Spring insertion holes 38, 38 extending in a tangential direction are formed in the clamp claws 27a, 27a adjacent to the clamp tool 27 so as to face each other, and positioning pins 39 are inserted into the spring insertion holes 38, 38. Retraction springs 41 composed of compression coil springs are respectively mounted between spring receiving seats 40 formed by enlarging the central portion in the axial direction of the positioning pins 39 and the bottom wall of each spring insertion hole 38.

The advancing inclined cam 31 is formed in a cylindrical shape, and a cam surface 43 is formed by an inner peripheral surface whose diameter increases as it goes downward.

A pneumatic cylinder 45, which is a fluid cylinder for cam advancement, is provided in the upper part of the cylinder body 5. The pneumatic cylinder 45 is configured as a single-acting spring return type, and its pneumatic piston 46 is linked to the advance inclination cam 31.

That is, a pneumatic piston 46, which is a fluid pressure piston, is inserted into the lid plate 10 so as to be slidable in a vertical direction. Below the pneumatic piston 46, a pneumatic working chamber which is a fluid working chamber
47 is formed, and a return spring chamber 48 is formed on the upper side. In the return spring chamber 48, a piston return spring 49 including an inner spring 49a and an outer spring 49b is mounted. Pneumatic piston
The advancing inclined cam 31 is inserted into a piston rod 51 projecting downward from 46 so as to be movable in the radial direction. Then, while the pneumatic piston 46 is driven to move backward by the air pressure of the pneumatic working chamber 47, the reciprocating spring 49 advances the inclining cam 31 through the pneumatic piston 46 downward. It is driven.

In addition, an unclamping piston 52 is inserted into the pneumatic working chamber 47 between the piston rod 51 and the cylinder portion 9 of the cylinder body 5 via the inner and outer O-rings 53 and 54 so as to be slidable vertically in an airtight manner. Is done. This piston for unclamping 52
Is larger than that of the pneumatic piston 46 for cam advance. The above-described expansion / contraction movement guide ring 34 is integrally formed below the unclamping piston 52. As shown in FIG. 2, the compressed air of the pneumatic source 58 is supplied to the compressed air supply / discharge port 57 communicating with the pneumatic working chamber 47 by the electromagnetic pneumatic supply / discharge valve 59 / supply / exhaust passage 60 / supply passage. It is supplied via a pneumatic hose 61 in order.

Further, a detection means 64 for detecting the advance / retreat position of the pneumatic piston 46 is provided. The detecting means 64 is provided with two proximity switches 67 and 68 in a switch box 65 fixed to the upper surface of the lid plate 10 with a plurality of bolts 66, and two pneumatic pistons 46 are provided to project upward. The height positions of the detected parts 70 and 71 are detected by the respective proximity switches 67 and 68. These detected parts 70 and 71 are pneumatic pistons with bolts 72 and 73, respectively.
Fixed to 46. Then, based on the output signal of the detection means 64, as shown in FIG. 2, the electric control panel 75 as a control means controls the pressure oil supply / discharge valve 18 and the pneumatic supply / discharge valve 59. It has become.

The operation of the hydraulic clamp 3 having the above configuration will be described mainly with reference to FIGS.

The switching from the unclamped state shown in FIGS. 1A and 2 to the clamped state shown in FIG. 1C is performed in the following procedure.

In order to switch to the unclamped state shown in FIGS. 1A and 2, pressurized oil is discharged from the clamp working oil chamber 15 and compressed air is supplied into the pneumatic working chamber 47. Then, the pneumatic piston 46 of the cam advancing pneumatic cylinder 45 is driven up, and at the same time, the unclamping piston 52 is driven down. As a result, the hydraulic piston 12 and the clamp 27 are lowered to the bottom dead center position, and each clamp claw 27a of the clamp 27 is moved by the retracting spring 41 of the retracting means 30 to the guide ring 34.
, And is switched to the non-clampable retreat position Y (see FIGS. 5 and 6). As a result, the rod insertion passage D is opened, the diameter of the inner peripheral surface of the clamp 27 becomes larger than the outer diameter of the passive portion 25, and the passive portion 25 can be inserted into and removed from the rod insertion passage D. It has become. In the unclamped state described above, the proximity switch 67 on the left detects the height position of the detected part 70 on the left, so that the clamp
27 is detected to be in the non-clampable retreat position Y, and after the detection, the cylinder body 5 is externally fitted to the clamp rod 2 from above.

At the time of the clamp drive, first, as shown in FIG. 1 (b), the compressed air is discharged from the pneumatic working chamber 47. Then
The resilient pressure of the piston return spring 49 causes the pneumatic piston 46 to drive the advance inclination cam 31 down to the bottom dead center side, and the clamp 27 reduces the retracting spring 41 and can be clamped along the guide ring 34. The diameter is moved to the position X (FIGS. 7 and 8
See figure). As a result, the rod insertion passage D is closed, and the output portion 29 of the clamp 6 faces the lower surface of the passive portion 25 of the clamp rod 6. In this state, the proximity switch 68 on the right side detects the height position of the detected part 71 on the right side, thereby detecting that the clamp member 27 is at the clampable advance position X. The supply of pressurized oil to the plant is allowed.

When pressure oil is supplied from the state shown in FIG. 1 (b) to the clamp hydraulic oil chamber 15, the state is switched to the clamp state shown in FIG. 1 (c). That is, the hydraulic piston 12 is driven upward by the clamp stroke M by the hydraulic pressure of the clamp working oil chamber 15. As a result, the clamp 27 is raised from the unclamped position U on the bottom dead center side to the clamp position C on the top dead center side against the elastic force of the return spring 49 while the clamp member 27 is maintained at the clampable advance position X. When driven, the clamp unit output unit 29 is
Contacts the lower surface of the. As a result, the hydraulic lifting force of the piston 12 is transmitted to the passive unit 25 via the clamp 27, and the clamp rod 6 is clamped upward. in this case,
A margin stroke N is formed in the space above the unclamping piston 52. The dimension obtained by adding the margin stroke N to the clamp stroke M is equal to the allowable stroke L of the hydraulic piston 12 (see FIG. 1B). Has become.

On the other hand, switching from the clamp state shown in FIG. 1 (c) to the unclamped state shown in FIG. 1 (a) is performed in the reverse procedure.

That is, in the clamp state of FIG. 1 (c), the pressurized oil is discharged from the clamp hydraulic oil chamber 15, and thereafter, the pneumatic hydraulic chamber
Supply compressed air into 47. Then, the air pressure causes the unclamping piston 52 having a large pressure receiving area to drive the hydraulic piston 12 downward as shown in FIG.
27 is switched from the clamping position C to the unclamping position U,
At about the same time, as shown in FIG. 1 (a), the cam advance pneumatic piston 46 having a small pressure receiving area is driven upward, and the clamp 27 is switched from the clampable advance position X to the non-clampable retreat position Y. It is replaced. In the descending drive process of the unclamping piston 52, the guide ring 34 descending along with the unclamping piston 52 moves each of the clamp claws 27a to the advancing inclined cam 3.
The downward movement of the clamp claws 27a, 27a, 27a in the direction in which the clamp claws 27a, 27a, 27a are moved away from 1 permits the diameter-increase movement.

According to this embodiment, when switching from the non-clampable retreat position Y to the clampable advance position X, the clamp tool 27 reduces the diameter of the clamp tool 27 substantially evenly on the axis A, thereby allowing the clamp tool output unit 29 to be passive. Since it is arranged over the entire circumference of the part 25,
The number of openings that cannot be transmitted is small, and a large transmission area can be secured. Therefore, the transmission capability of the clamp 27 is increased, and the clamping capability of the hydraulic clamp 3 is increased. Further, since the transmission area of the clamp tool output unit 29 is large, the contact pressure between the clamp tool output unit 29 and the passive unit 25 is reduced. In addition, since the clamp output section 29 is arranged substantially evenly over the entire circumference of the passive section 25, stress concentration and bending stress are less likely to occur on the clamp rod 6, and the durability of the clamp rod 6 is improved.

FIG. 9 and FIG. 10 are diagrams corresponding to FIG. 1 (b) showing different embodiments, respectively, and explain a configuration different from the above-mentioned first embodiment. Members having the same functions as those of the first embodiment are given the same reference numerals in principle.

(Second embodiment) Fig. 9 shows a second embodiment.

In this case, the detecting means 64 of the advance / retreat position of the pneumatic piston is
It is provided in the cover plate 10. That is, the detection rod 80 slidably inserted into the cover plate 10 in the up and down direction is elastically pressed against the upper surface of the pneumatic piston 89 for cam advancement by the spring 81. The detection rod 80
Below the spring receiving portion 84, a depression groove 82 for detecting the clamp tool diameter reduction and a step-up portion 83 for detecting the clamp tool diameter expansion are formed vertically. A proximity switch 85 for detecting a clamp tool diameter increase and a proximity switch 86 for detecting a clamp tool diameter reduction are arranged vertically above the depression groove 82.

Further, the advance inclination cam 88 is driven downward by the return spring 49 of the pneumatic cylinder 45, whereas it is driven upward by the air pressure of the pneumatic working chamber 47 via the pneumatic piston 89. . The pneumatic working chamber 47 is communicated with a supply / exhaust port 57 via a supply / exhaust hole 90 in the cover plate 10.

The expansion / contraction movement guide ring 92 is provided separately from the unclamping piston 52.

Further, a proximity switch 94 for detecting unclamping is provided below the cylinder body 5.

The cylinder body 5 can be fixed to another fixed object via a female screw 95 for connection provided at the center of the cover plate 10.

Third Embodiment FIG. 10 shows a third embodiment.

In this case, the hydraulic piston 12 is configured as a spring return type instead of the pneumatic return type. That is, the cylinder body 5
An annular spring receiver 96 is fixedly provided in the upper portion, and a piston return spring 98 is mounted between the spring receiver 96 and the expansion / contraction movement guide ring 97. The pneumatic working chamber 47 is hermetically sealed by an O-ring on the inner peripheral surface of the spring receiver 96.

In each of the above embodiments, the clamp rod 6 is fixed and the cylinder body 5 is movable. Instead, the cylinder body 5 is fixed and the clamp rod 6 is movable. Is also good. In this case, instead of the clamp rod 6, the clamp passive member may be a fixed object itself such as a screw cylinder or a work chuck of an injection molding machine, or a connected pipe for piping.

[Brief description of the drawings]

1 to 10 show an embodiment of the present invention. 1 to 8 show a first embodiment. FIG. 1 is an explanatory view of the operation of a hydraulic clamp. FIG. 1 (a) shows an unclamped state, and FIG. 1 (b) shows a switching transient state. FIG. 2 (c) is a view showing a clamp state, FIG. 2 is an overall view showing a use state of a hydraulic clamp, FIG. 3 is a sectional view taken along line III-III of FIG. FIG. 4 is an exploded perspective view showing the clamp and the retracting means, FIG. 5 is a plan view showing a state in which the clamp is switched to the unclampable retracting position, and FIG. 6 is a view taken along the line VI-VI in FIG. FIG. 7 is a plan view showing a state in which the clamp is switched to a clampable advance position, and FIG. 8 is a sectional view taken along line VIII-VIII in FIG. 9 and 10 show a second embodiment and a third embodiment, respectively, and are diagrams corresponding to FIG. 1 (b). 1 ... Fixed side member (fixed table), 4 ... Hydraulic cylinder, 5
…… Cylinder body, 6… Passive passive member for clamping (clamp rod), 12… Hydraulic piston, 14… Rod insertion hole, 15… Clamp hydraulic oil chamber, 18… Pressure oil supply / discharge means (electromagnetic pressure Oil supply / discharge valve), 25: passive part, 27: clamp
27a …… Clamp claw, 29 …… Clamp output section, 30 ……
Retracting means, 31: Inclined cam for advance, 34: Ring for expansion and contraction movement guide, 35 ... Peripheral groove for expansion and contraction movement guide, 45 ... Fluid pressure cylinder, 46 ... Fluid pressure piston (pneumatic piston), 47 …
… Fluid pressure working chamber (pneumatic working chamber), 48 …… Return spring chamber, 49
...... Return spring, 64 ... Detection means, 75 ... Control means (electric control panel), A ... Axial axis of hydraulic cylinder 4, C ... Clamp position, D ... Insertion path, U ... Unclamp position , X ...
… Clampable advance position, Y… Clamp impossible retreat position.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B23Q 3/06 F16B 2/06

Claims (6)

(57) [Claims] Cylinder body (5) of a hydraulic cylinder (4)
Between one end and the other end of the
5) ・ Hydraulic piston (12) and clamp tool (27) are provided in this order. The clamp tool (27) has at least the clamp tool output section (29) provided on the other end side, and the axis of hydraulic cylinder (4). A)
The movable position is different between the clampable advance position (X) and the non-clampable retreat position (Y) at different distances from each other, and at the clampable advance position (X), the axis (A) of the hydraulic cylinder (4) Along the axis, it is configured to be able to advance and retreat to an unclamping position (U) on one end side and a clamping position (C) on the other end side. It is configured so that it can be pushed to the Y) side and can be pushed out to the advance position (X) side, which can be clamped by the advance inclination cam (31). A hydraulic clamp configured to be pushed from the unclamping position (U) to the clamping position (C) by the hydraulic pressure of the hydraulic piston (12) after being pushed out from the (Y) to the clampable advance position (X). In, Sirin At the other end of the main body (5), a fluid cylinder (45) for cam advancement is attached, and the movable side members (46, 49) of the fluid pressure cylinder (45) are linked to the inclined cam (31) for advancement, A hydraulic system characterized in that the cylinder movable side members (46) and (49) are configured to be able to advance the advance inclination cam (31) from the non-clampable retreat position (Y) to the clampable advance position (X). Clamp. The fluid cylinder (45) for cam advancement has a fluid pressure operating chamber (47) formed at one end of a fluid pressure piston (46) and a return spring chamber (48) formed at the other end. The fluid pressure piston (46) with the fluid pressure of the fluid pressure working chamber (47)
To the other end, the return spring chamber (4
8) With the elastic pressure of the return spring (49) inside, the inclining cam (3
2. The hydraulic clamp according to claim 1, wherein the hydraulic clamp is configured to be driven toward one end. 3. A fluid pressure piston (46) is provided with a detecting means (64) for detecting its advanced / retracted position, and an output signal of the detecting means (64) is linked to an input of a control means (75). The control means (75) controls the clamp hydraulic oil chamber (15) of the hydraulic cylinder (4) based on the detection means (64) detecting the state in which the fluid pressure piston (46) has advanced to one end side. The hydraulic clamp according to claim 1, wherein the hydraulic oil supply of the hydraulic oil supply / discharge means (18) connected to the hydraulic clamp is configured to be allowed. 4. A clamping tool (27) comprising a plurality of clamp claws (27a) arranged in a ring, and a circumferential groove (35) for guiding expansion and contraction over a plurality of clamp claws (27a) arranged in a ring. 4. The expansion / contraction movement guide ring (34) is slidably guided in the radial direction across the expansion / contraction movement guidance peripheral groove (35), and is fitted. Hydraulic clamp. 5. An insertion hole (14) is formed in the piston (12) substantially coaxially with the axis (A) of the hydraulic cylinder (4), and an insertion passage (D) is formed in the clamp (27). The passive member for clamping (6) is inserted into the insertion hole (14) and the insertion passage (D).
Are inserted in order from one end of the cylinder body (5) to the other end, and the other end of the passive member for clamping (6) is enlarged to form a passive part (25). The evacuation means (30) can be expanded by the evacuation means (30) to a non-clampable evacuation position (Y) away from the axis (A) of the hydraulic cylinder (4), and the same clamping tool (27) The inclining cam (31) for advancing is configured to be capable of reducing the diameter of the hydraulic cylinder (4) to a clampable advancing position (X) close to the axis (A) of the hydraulic cylinder (4). Hydraulic clamp. 6. A clamped passive member (6) is fixed at one end to a fixed side member (1), and a cylinder body (5) is attached to and detached from a passive portion (25) of the clamped passive member (6). The hydraulic clamp according to claim 5, wherein the hydraulic clamp is configured as follows.