JP4318925B2 - Clamping device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a clamp device of a type that expands and contracts a clamp tool.
[0002]
[Prior art]
Conventionally, this type of clamping device is described in Japanese Patent Laid-Open No. 1-123708 previously proposed by the present applicant.
In the prior art, an annular piston for receiving a clamp rod and an annular clamp tool are provided in this order in the lower half of the housing, and the diameter of the clamp tool is expanded by a retracting spring. Further, an annular advance cam is arranged in the upper half of the housing so as to be movable in the axial direction and in the radial direction, and a taper for reducing the diameter of the clamp tool on the inner peripheral surface of the annular advance cam. A surface is provided.
[0003]
[Problems to be solved by the invention]
In the above prior art, when the annular advance cam reduces the diameter of the clamp tool, the advance cam moves in the radial direction due to the frictional resistance at the time of the diameter reduction, and the clamp tool is uniformly compressed. There was a risk that the diameter could not be achieved. For this reason, there is room for improvement in driving the clamp rod powerfully and reliably.
An object of the present invention is to enable a passive member such as a clamp rod to be driven strongly and reliably.
[0004]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, for example, as shown in FIG. 1 to FIG. 4 or FIG. 5, the clamping device is configured as follows.
An annular output member 10 for receiving the clamping passive member 6 and an annular clamping tool 27 are sequentially provided in the housing 5 in the distal direction. The clamp tool 27 is configured to be expanded in diameter to the radially outward retracted position Y by the retracting means 30 and to be reduced in diameter to the radially inward advanced position X by the annular advance cam 31. The outer peripheral surface 32 of the annular advance cam 31 is supported on the body portion 9 of the housing 5 in a state where the outer peripheral surface 32 is movable in the axial direction and is prevented from moving in the radial direction. On the inner peripheral surface of the annular advance cam 31, an inclined surface 42 that presses the clamp tool 27 from the retracted position Y to the advanced position X and a holding surface that holds the clamp tool 27 at the advanced position X are the same. 43 are provided in this order in the distal direction. In the housing 5, a fluid pressure cylinder 45 for reciprocating the advance cam 31 in the axial direction, a lock means 21 for moving the output member 10 in the distal direction, and the output member 10 in the proximal direction. And release means 22 for moving to the position.
[0005]
The invention according to claim 1 has the following effects.
Since the outer peripheral surface of the annular advance cam is supported in a state where the outer peripheral surface of the annular advance cam is movable in the axial direction and is prevented from moving in the radial direction on the body of the housing, the fluid pressure cylinder supports the advance cam. When moving in the direction, the housing body guides the advance cam straight. For this reason, the inclined surface of the advancing cam reduces the diameter of the annular clamp tool substantially uniformly. In addition, the holding surface provided on the advance cam can hold the clamp member having the uniform reduced diameter in the uniform reduced diameter state. For this reason, at the time of lock driving, the locking means can drive the clamping passive member powerfully and reliably through the output member and the clamp tool having the uniformly reduced diameter.
[0006]
As shown in the invention of claim 2, it is preferable to add the following configuration to the invention of claim 1 described above.
For example, as shown in FIGS. 1 to 4, the locking means 21 includes a piston 11 provided on the output member 10 and a lock spring 16 attached to the proximal end side of the piston 11, and the release means 22. Is constituted by the piston 11 and a release fluid pressure chamber 18 disposed on the tip end side of the piston 11.
[0007]
In the second aspect of the invention, since the lock spring locks the passive member for clamping via the piston and the clamp tool, unlocking caused by leakage of pressure fluid such as pressure oil can be prevented. .
[0008]
As shown in the invention of claim 3, it is preferable to add the following configuration to the invention of claim 1.
For example, as shown in FIG. 5, the locking means 21 includes a piston 11 provided in the output member 10 and a locking fluid pressure chamber 54 disposed on the proximal end side of the piston 11, and the release The means 22 includes a release fluid pressure chamber 63 provided on the distal end side of the piston 11.
[0009]
According to the third aspect of the present invention, a pressure fluid such as pressure oil supplied to the lock fluid pressure chamber locks and drives the clamp passive member via the piston and the clamp tool. Since the height of the lock fluid pressure chamber can be made significantly smaller than the height of the spring chamber for mounting the lock spring according to claim 2, the clamp device can be made compact.
In addition, as described in the first aspect of the present invention, since the holding surface of the advance cam holds the clamp tool in a reduced diameter state, the lock is caused by leakage of pressure fluid such as pressure oil. Release can be prevented.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
1 to 4 show a first embodiment of the present invention. First, a schematic configuration of the clamping device will be described with reference to the overall view of FIG.
An object to be fixed 2 is fixed to the upper surface of the fixing base 1 that is a fixed side member via a housing 5 of the clamp device 3 and a clamp rod (passive passive member for clamping) 6. A through hole 7 is formed in the fixed object 2 substantially coaxially with the axis A of the housing 5. The housing 5 is attached to the upper surface of the fixed object 2 with a plurality of bolts 8. Further, a leg screw 6 a at the lower end (base end) of the clamp rod 6 is screwed to the fixed base 1.
[0011]
At the time of the locking operation, first, as shown in a two-dot chain diagram in FIG. 1, the fixed object 2 and the housing 5 are externally fitted to the clamp rod 6 from above, and then the clamp rod 6 to be described later is clamped. The tool 27 is engaged, and subsequently, a pulling force is applied to the clamp rod 6 by a lock spring 16 to be described later, and the fixed object 2 is moved upward by the downward reaction force acting on the housing 5. It is pressed and fixed to.
[0012]
A specific structure of the clamp device 3 will be described with reference to schematic views of FIGS. 2 shows a release state of the clamp device 3, FIG. 3 shows a switching halfway state, and FIG. 4 shows a locked state.
An annular output member 10 is inserted into the cylinder portion (body portion) 9 of the housing 5 so as to be movable in the vertical direction. The output member 10 includes a piston 11 and a piston rod 12 that are inserted into the cylinder portion 9 in a close-packed manner, and a guide rod 13 that protrudes downward from the piston 11.
[0013]
A rod insertion hole 14 passes through the output member 10 substantially coaxially with the axis A of the housing 5.
A lock chamber 15 is formed between the lower wall (base end wall) 5 a of the housing 5 and the piston 11, and a lock spring 16 is attached to the lock chamber 15. Here, the lock spring 16 is constituted by a large number of disc springs stacked in the vertical direction, but may be a compression coil spring. A release chamber (release fluid pressure chamber) 18 is formed between the intermediate wall 5 c of the housing 5 and the piston 11, and a pressure oil supply / discharge port 19 is communicated with the release chamber 18.
[0014]
That is, the piston 11 and the lock spring 16 constitute a lock means 21 that moves the output member 10 upward (toward the distal end). The piston 11 and the release chamber 18 constitute release means 22 that moves the output member 10 downward (toward the proximal direction).
[0015]
In addition, a circumferential groove 24 and a passive portion 25 are sequentially formed upward on the clamp rod 6. An annular clamp 27 that is engaged and disengaged with the passive portion 25 and an annular advance cam 31 that engages with the clamp 27 are disposed in the upper half of the cylinder portion 9.
[0016]
The clamp tool 27 is placed on the upper surface of the piston rod 12, and here is composed of clamp claws 28, 28, and 28 divided into three pieces in the circumferential direction. These clamp claws 28 are expanded in diameter in the radially outward retracted position Y (see FIG. 1 or FIG. 2) by the retracting means 30 and radially advanced inward by the advancing cam 31. The diameter is reduced to X (see FIG. 3 or FIG. 4).
The retracting means 30 is configured as follows. The adjacent clamp claws 28, 28 are formed with spring insertion holes 38, 38 (only one hole 38 is shown here) extending in a tangential direction so as to face each other. The positioning pin 39 is inserted into the. A retraction spring 40 made of a compression coil spring is mounted between a spring receiver (not shown) in the axial center of the positioning pin 39 and the bottom wall of each spring insertion hole 38.
[0017]
The outer circumferential surface of the annular advance cam 31 is supported by the cylinder portion 9 in a confined state while being movable in the axial direction and preventing movement in the radial direction. Further, on the inner peripheral surface of the annular advance cam 31, a tapered surface (inclined surface) 42 that narrows upward and a straight holding surface 43 are provided in an upward direction.
[0018]
A pneumatic cylinder (fluid pressure cylinder) 45 for moving the advance cam 31 in the axial direction is provided in the upper portion of the cylinder portion 9. The pneumatic cylinder 45 is configured as a double-acting type, and the pneumatic piston 46 is fixed to the advance cam 31. More specifically, the pneumatic piston 46 is inserted into the upper portion of the cylinder portion 9 so as to be hermetically slidable in the vertical direction. A rising working chamber 47 is formed on the lower side of the pneumatic piston 46, and a lowering working chamber 48 is formed on the upper side. A holding spring 49 for urging the pneumatic piston 46 downward is attached to the lowering working chamber 48.
In addition, in order to confirm the raising / lowering position of said pneumatic piston 46, the detection rod 50 protrudes upward from the pneumatic piston 46, and the detection tool screwed to the detection rod 50 is a sensor (none is shown). ) To detect.
[0019]
The operation of the clamp device 3 configured as described above will be described with reference to FIGS.
Switching from the released state of FIG. 2 to the locked state of FIG. 4 is performed in the following procedure.
In the released state of FIG. 2, pressure oil is supplied to the release chamber 18, and the output member 10 is lowered against the lock spring 16. Further, the compressed air in the descending working chamber 48 is discharged and the compressed air is supplied to the ascending working chamber 47 to raise the pneumatic piston 46 and the advance cam 31. As a result, each clamp claw 28 of the clamp tool 27 is expanded in diameter to the retracted position Y by the retracting spring 40. For this reason, the diameter of the inner peripheral surface of the clamp tool 27 is larger than the outer diameter of the passive portion 25 of the clamp rod 6. In this state, the housing 5 is externally fitted to the clamp rod 6 from above.
[0020]
When the lock is driven, as shown in FIG. 3, the compressed air in the ascending working chamber 47 is discharged and the compressed air is supplied to the descending working chamber 48. Then, the pneumatic piston 46 lowers the advance cam 31. From the initial stage to the late stage of the lowering, the tapered surface 42 moves the clamp tool 27 to the advanced position X against the retracting spring 40, whereby the output portion 29 of each clamp pawl 28 is moved to the clamp. The rod 6 faces the lower surface of the passive portion 25 described above. At the end of the lowering of the advance cam 31, the holding surface 43 covers the outer peripheral surface of the clamp tool 27, thereby holding the clamp tool 27 at the advanced position X.
[0021]
Thereafter, as shown in FIG. 4, the pressure oil in the release chamber 18 is discharged. Then, the lock spring 16 strongly raises the clamp tool 27 via the output member 10, and the output part 29 of the clamp tool 27 pushes up the passive part 25 so that the clamp rod 6 faces upward. To drive.
[0022]
On the other hand, switching from the locked state in FIG. 4 to the released state in FIG. 2 is performed in the reverse procedure to the above.
That is, in the locked state of FIG. 4, first, as shown in FIG. 3, pressure oil is supplied to the release chamber 18 to lower the output member 10. Thereafter, as shown in FIG. 2, the compressed air in the descending working chamber 48 is discharged and the compressed air is supplied to the ascending working chamber 47. Then, as shown in FIG. 2, the pneumatic piston 46 and the advance cam 31 are raised, and the retraction spring 40 expands the diameter of the clamp tool 27 to the retraction position Y.
[0023]
FIG. 5 shows a second embodiment of the present invention and is similar to FIG. In the second embodiment, the same members (or similar members) as the constituent members of the first embodiment are given the same reference numerals in principle.
[0024]
The second embodiment of FIG. 5 differs from the first embodiment in the following points.
A locking fluid pressure chamber 54 is formed short between the lower wall 5 a of the housing 5 and the piston 11, and a pressure oil supply / discharge port 55 is communicated with the locking fluid pressure chamber 54.
An annular release piston 57 is inserted between the cylinder portion 9 and the advance cam 31 in a tightly sealed manner via upper and lower sealing tools 58 and 59. Thereby, the outer peripheral surface 32 of the advancing cam 31 is supported by the cylinder portion 9 through the release piston 57 in a state that it can move in the axial direction and is prevented from moving in the radial direction.
On the inner peripheral surface of the annular advance cam 31, similarly to the first embodiment, a tapered surface (inclined surface) 42 that narrows upward and a straight holding surface 43 are connected upward.
[0025]
The advance cam 31 is urged downward by the descending spring 61, and the ascending piston 62 is fixed to the advance cam 31. An air pressure working chamber (release fluid pressure chamber) 63 is formed between the lift piston 62 and the release piston 57. The pressure receiving cross-sectional area of the release piston 57 is larger than the pressure receiving cross-sectional area of the lift piston 62 described above.
In the locked state of FIG. 5, the compressed air in the pneumatic working chamber 63 is discharged, and the lowering spring 61 reduces the diameter of the clamp tool 27 to the advanced position X via the advanced cam 31. . Further, pressure oil is supplied to the fluid pressure chamber 54 for locking, and the output member 10 pushes up the passive portion 25 of the clamp rod 6 via the clamp tool 27.
[0027]
When the locked state in FIG. 5 is switched to the released state, the pressure oil in the locking fluid pressure chamber 54 is discharged, and then compressed air is supplied to the pneumatic working chamber 63. Then, due to the air pressure, the release piston 57 with the large pressure receiving area lowers the clamp tool 27 and the output member 10, and at the same time, the raising piston 62 with the small pressure receiving area rises, The retraction spring 40 expands the diameter of the clamp tool 27 to the retraction position.
[0028]
In the second embodiment of FIG. 5 described above, the locking means 21 is configured by the piston 11 of the output member 10 and the locking fluid pressure chamber 54 below the piston 11. Further, the release means 22 is constituted by the release piston 57 provided above the piston 11 and the pneumatic working chamber (release fluid pressure chamber) 63. However, the release means 22 may include a release fluid pressure chamber similar to the release chamber 18 of the first embodiment (see FIGS. 1 to 4) described above.
[0029]
Each of the above embodiments can be modified as follows.
The tapered surface 42 of the advance cam 31 can be replaced by a plurality of inclined surfaces provided at intervals in the circumferential direction. Further, the holding surface 43 may be provided in a plural number at intervals in the circumferential direction instead of being constituted by a continuous circumferential surface.
Four or more clamp claws 28 constituting the annular clamp tool 27 may be provided instead of the three illustrated.
Of course, the annular clamp 27 may be any one that expands and contracts in the radial direction, and is not limited to the illustrated structure.
[0030]
The clamp rod 6 is fixed and the housing 5 is movable. Alternatively, the housing 5 may be fixed and the clamp rod 6 may be movable. In this case, 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 pipe connection pipe instead of the clamp rod 6. .
[Brief description of the drawings]
FIG. 1 is an overall view showing a use state of a clamp device according to a first embodiment of the present invention.
FIG. 2 is a sectional view in an elevational view of the clamp device in a released state.
FIG. 3 is a view similar to FIG. 2 showing a state in which the clamp device is being switched.
FIG. 4 is a view similar to FIG. 2 showing the locked state of the clamp device.
FIG. 5 is a view similar to FIG. 4 showing a second embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 5 ... Housing, 6 ... Passive member for clamping (clamp rod), 9 ... Body part (cylinder part) of housing 5, 10 ... Output member, 11 ... Piston, 16 ... Lock spring, 18 ... Release fluid pressure chamber (release chamber) , 21 ... Locking means, 22 ... Release means, 27 ... Clamping tool, 30 ... Retraction means, 31 ... Advance cam, 32 ... Outer peripheral surface of the advance cam 31, 42 ... Inclined surface (tapered surface), 43 ... Holding surface, 45 ... Fluid pressure cylinder (pneumatic cylinder), 54 ... Locking fluid pressure chamber, 63 ... Release fluid pressure chamber (pneumatic working chamber), X ... Advance position, Y ... Retreat position.

Claims (3)

An annular output member (10) for receiving the clamping passive member (6) and an annular clamping tool (27) are provided in the housing (5) in this order in the distal direction.
The clamp tool (27) has its diameter expanded to the radially outward retracted position (Y) by the retracting means (30), and the radially inward advanced position (X) by the annular advance cam (31). It is possible to reduce the diameter to
The outer surface (32) of the annular advance cam (31) is supported on the body (9) of the housing (5) in a state that is movable in the axial direction and prevented from moving in the radial direction,
On the inner peripheral surface of the annular advance cam (31), the clamp (27) is the same as the inclined surface (42) for reducing the diameter of the clamp (27) from the retracted position (Y) to the advanced position (X). 27) and a holding surface (43) for holding the advanced position (X) in the above-mentioned advance position (X) are provided in the distal direction,
In the housing (5), a fluid pressure cylinder (45) for reciprocating the advance cam (31) in the axial direction, and a lock means (21) for moving the output member (10) in the distal direction. And a release means (22) for moving the output member (10) of the above in the proximal direction. The clamping device according to claim 1,
The locking means (21) is constituted by a piston (11) provided on the output member (10) and a lock spring (16) attached to the base end side of the piston (11),
The clamping device according to claim 1, wherein the release means (22) is constituted by the piston (11) and a release fluid pressure chamber (18) disposed on a tip end side of the piston (11). The clamping device according to claim 1,
The locking means (21) is constituted by a piston (11) provided on the output member (10) and a locking fluid pressure chamber (54) disposed on the proximal end side of the piston (11),
The clamping device according to claim 1, wherein the release means (22) includes a release fluid pressure chamber (63) provided on a distal end side of the piston (11).

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