JP7141691B2 - clamping device - Google Patents

Description

The present invention relates to clamping devices.

As this type of clamping device, there is a conventional one described in Patent Document 1 below. The prior art is configured as follows.
A circular mounting hole into which a predetermined portion on the lower side of the clamp body is inserted is formed in the base member, and between a part of the inner peripheral surface of the mounting hole and a part of the outer surface of the predetermined portion on the lower side. An annular gap is formed. The upper and lower ends of this annular gap are sealed by a pair of sealing members. Pressurized air is supplied through the annular gap to the pressurized air ejection holes formed in the workpiece seating surface of the clamp body.
With the above configuration, the positions of the pressurized air ejection holes can be adjusted according to the shape of the workpiece by adjusting the rotational position (circumferential position) of the clamp body.

Japanese Patent No. 5885822

The above prior art has the following problems.
In the above-described prior art, the seal member fitted to the outer periphery of the lower side of the clamp body seals between the pressure oil passage for driving the clamp rod and the air passage for pressurized air. Here, in order to change (adjust) the position of the pressurized air ejection hole, the clamp body is turned around its axial direction. However, it is not preferable to rotate the clamp body, because rotating the clamp body may damage the sealing member. If the sealing by the sealing member is broken and the pressurized oil leaks into the air passage or the pressurized air leaks into the oil passage, the clamp device may malfunction.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a clamping device that can easily change the position of a fluid discharge hole provided on the release side of a housing without turning the housing.

In order to achieve the above objects, the present invention, for example, as shown in FIGS. 1 to 4, has a clamping device configured as follows.

The clamping device of the present invention comprises a housing 2 provided with fluid supply ports 43 and 46, a clamp rod 32 inserted into the housing 2, and axially moving the clamp rod 32 between the locking side and the releasing side. A driving means 50, and an annular member 30 fixed to the end of the housing 2 on the release side and into which the clamp rod 32 is inserted, the annular member 30 having a fluid ejection hole 40 through which fluid is ejected. And prepare. A first fluid passage 44 communicating with the fluid supply ports 43 and 46 is formed inside the housing 2 , and a second fluid passage communicating with the fluid discharge hole 40 is formed inside the annular member 30 . A passage 41 is formed. At least one of the facing surface 30 a of the annular member 30 facing the housing 2 and the facing surface 2 c of the housing 2 facing the annular member 30 is provided with the first fluid passage 44 and the second fluid passage 41 . or the diameter of the first fluid passage 44 or the diameter of the second fluid passage 41, which communicates the first fluid passage 44 and the second fluid passage 41. Large-diameter grooves 51, 54, 55 are formed.

ADVANTAGE OF THE INVENTION The clamp apparatus of this invention has an effect as follows.
At least one of the facing surface of the annular member that faces the housing and the facing surface of the housing that faces the annular member is circumferentially provided with the first fluid passage in the housing and the second fluid passage in the annular member. By forming an extending groove or a groove having a diameter larger than the diameter of the first fluid passage or the second fluid passage, by turning the annular member without turning the housing, the fluid supply port and the fluid discharge hole can be separated. It is possible to easily change the position of the fluid discharge hole provided on the release side of the housing while maintaining communication.

Preferably, the clamping device of the present invention further comprises the following configuration.
A pressing member 45 is provided for fixing the annular member 30 to the end of the housing 2 on the release side by frictional force by pressing the annular member 30 against the housing 2 .
According to this configuration, the circumferential position of the fluid discharge hole can be changed to any position.

ADVANTAGE OF THE INVENTION According to this invention, the clamp apparatus which can change the position of the fluid discharge hole provided in the release side of a housing easily can be provided, without turning a housing.

FIG. 1 shows a first embodiment of the present invention, and is a cross-sectional view of a clamp device in a released state as seen in elevation. FIG. 2A is a plan view of a housing that constitutes the clamp device. FIG. 2B is a plan view of an annular member that constitutes the clamp device. FIG. 3 is a sectional elevational view of the clamp device in a locked state. FIG. 4 shows a second embodiment of the present invention, and is a cross-sectional view of a clamping device in a released state as viewed in elevation. FIG. 5 is a view corresponding to FIG. 2B showing a modification of the annular member.

1 to 3 show a first embodiment of the invention.
This embodiment exemplifies the case where the present invention is applied to a hole clamping device that clamps a work piece using a hole in the work piece.
First, the overall configuration of the clamping device of the first embodiment will be described mainly with reference to FIGS. 1, 2A, and 2B.

A housing 2 is attached to a clamp pallet 1 as a fixed base, and a cylinder hole 3 is formed in the housing 2 . The cylinder hole 3 has an upper hole 4 and a lower hole 5 larger in diameter than the upper hole 4 .

A first piston 11 is hermetically inserted into the pilot hole 5 via a lower sealing member 6 . The tip side portion of the rod portion 11a of the first piston 11 is hermetically inserted into the cylindrical portion 2a provided on the upper portion of the housing 2 through the upper sealing member 7. As shown in FIG.

An annular second piston 12 is hermetically inserted into the upper hole 4 via an outer sealing member 8, and the second piston 12 is inserted via an inner sealing member 9 into the first piston 11. is fitted on the rod portion 11a so as to be tightly movable in the vertical direction.

A lock chamber 10 to which compressed air is supplied and discharged is arranged between the first piston 11 and the second piston 12 . The lock chamber 10 communicates with a lock port 19 via a lock supply/discharge path 18 . A holding spring 13 is mounted between the first piston 11 and the second piston 12 within the lock chamber 10 . The holding spring 13 is a compression coil spring and biases the second piston 12 upward with respect to the first piston 11 .

A first release chamber 14 to which compressed air is supplied and discharged is arranged below the first piston 11, and a second release chamber 14 to which compressed air is supplied and discharged is arranged above the second piston 12. A release chamber 15 is provided. The second release chamber 15 communicates with a release port (not shown) via a release supply/discharge path 16 . Also, the first release chamber 14 communicates with the second release chamber 15 via a communication passage 17 formed in the first piston 11 .

A booster mechanism 20 is arranged in the second release chamber 15 . The boosting mechanism 20 reverses the force of the compressed air supplied to the lock chamber 10 pushing the second piston 12 upward into a downward force and boosts the force to the rod portion 11a of the first piston 11. configured to transmit. The booster mechanism 20 is configured as follows.

Four lateral grooves 21 are formed in the lower portion of the cylindrical portion 2a provided in the upper portion of the housing 2 at predetermined intervals in the circumferential direction. A receiving portion 22 is formed by the bottom wall of each lateral groove 21 . Further, four recesses 23 are formed at predetermined intervals in the circumferential direction on the outer peripheral surface of the middle height portion of the rod portion 11a. A bottom wall of each recess 23 constitutes a transmission portion 24 . The transmission portion 24 is formed so as to approach the axial center of the rod portion 11a as it goes upward. The upper portion of the communication passage 17 is opened to the bottom surface of the recess 23. As shown in FIG.

A wedge space 26 is formed between each receiving portion 22 and each transmitting portion 24 so as to narrow inward in the radial direction. An engaging ball 27 is inserted into the wedge space 26 . A boosting portion 28 is provided on the second piston 12 so as to push the engaging ball 27 radially inward. The force multiplier 28 has an inclined surface provided on the inner peripheral surface of the second piston 12 . An arcuate pressing portion 29 is provided above the force boosting portion 28 on the upper portion of the second piston 12 .

The first piston 11, the second piston 12, the booster mechanism 20, and the like constitute driving means 50 for axially moving a clamp rod 32, which will be described later, between the locking side and the releasing side.

An annular member 30 is fixed to the upper end of the housing 2 with a plurality of bolts 31 . A clamp rod 32 is inserted into the annular member 30, and a plurality of pressing members 33 are arranged around the clamp rod 32 so as to be horizontally movable and vertically movable. The pressing member 33 is urged upward by an advancing spring 34 via a spring receiving member 35 . The pressing member 33 includes a base portion 36 that contacts the upper surface of the spring receiving member 35 and a grip portion 37 that presses the inner peripheral surface of the hole H of the workpiece W. As shown in FIG.

A band-like elastic body 38 is attached to the outer periphery of the plurality of pressing members 33 , and the elastic body 38 biases each pressing member 33 toward the axial center of the clamp rod 32 . The inner peripheral lip portion of the scraper 39 is brought into contact with the outer peripheral surface of the band-like elastic body 38 . The plurality of pressing members 33 can be moved radially outward by the tapered surface 32a of the clamp rod 32. As shown in FIG. A T-leg 32b provided at the lower portion of the clamp rod 32 is fitted to the upper portion of the rod portion 11a so as to be horizontally movable.

A seating surface S is formed on the upper end surface of the annular member 30 . As shown in FIG. 2B, a plurality of seating surfaces S are formed in the circumferential direction. An air discharge hole 40 serving as a fluid discharge hole for discharging compressed air is formed in one of the plurality of seating surfaces S. Inside the annular member 30, an air passage 41 (second fluid passage) communicating with the air discharge hole 40 is formed. is formed with an arcuate groove 42 communicating with the air passage 41 and extending in the circumferential direction.

An air supply port 43 as a fluid supply port is provided on the side surface of the housing 2, and an air passage 44 (first fluid passage) communicating with the air supply port 43 is formed inside the housing 2. . The groove 42 formed in the lower surface 30a of the annular member 30 allows the air passage 44 and the air passage 41 to communicate with each other.

The clamp device having the above configuration operates as follows.
In the released state shown in FIG. 1, compressed air is discharged from the lock chamber 10 and compressed air is supplied to the first release chamber 14 and the second release chamber 15 . As a result, the first piston 11 is raised and the second piston 12 is lowered. Further, since the rod portion 11a of the first piston 11 lifts the clamp rod 32, the elastic body 38 moves the plurality of pressing members 33 radially inward, and the advance spring 34 pushes the pressing members 33. biased to the raised position.

In this state, the work piece W is carried above the housing 2 and the hole H of the work piece W is fitted to the pressing member 33 . Then, the lower surface of the workpiece W is received by the receiving surface R of the pressing member 33 . At this time, since the receiving surface R is positioned slightly higher than the seating surface S of the annular member 30 , a gap is formed between the lower surface of the workpiece W and the seating surface S of the annular member 30 . Therefore, the compressed air from the air supply port 43 passes through the air passage 44, the groove 42, and the air passage 41 and is discharged to the outside from the air discharge hole 40, and the pressure of the air supply port 43 becomes lower than the predetermined pressure. Become. By detecting the pressure state with a sensor such as a pressure switch, it is confirmed that the workpiece W is not placed on the seating surface S of the clamp device.

When the clamping device is driven to lock, in the released state of FIG. Then, the pushing portion 29 of the second piston 12 rapidly moves the engaging ball 27 radially inward, and subsequently, as shown in FIG. Forcefully push inward.

As a result, the upward thrust acting on the second piston 12 is converted into a downward force via the force multiplier 28 and the engaging ball 27, and the rod portion 11a of the first piston 11 is strongly driven downward. be. Therefore, the rod portion 11a is powerfully driven downward by the combined force of the pushing force of the force boosting mechanism 20 and the pushing force of the first piston 11. As shown in FIG.

During the double force driving, the tapered surface 32a of the clamp rod 32 pushes the pressing member 33 held at the raised position by the biasing force of the advancing spring 34 outward in the radial direction, and the grip portion 37 of each pressing member 33 is pushed out. The work piece W is brought into contact with the inner peripheral surface of the hole H of the work piece W, and the work piece W is pulled down while the hole H is lined. As a result, the workpiece W is strongly pressed against the seating surface S at the upper end of the annular member 30 .

In the locked state of FIG. 3, the lower surface of the workpiece W closes the air discharge hole 40 formed in the seating surface S of the annular member 30 . Therefore, the pressure of the air supply port 43 rises above the predetermined pressure. By detecting the pressure state with a sensor such as a pressure switch, it is confirmed that the workpiece W is placed on the seating surface S of the clamp device.

In the locked state, the wedge-driven engagement ball 27 is held in the wedge-engaged state by the retaining spring 13, so that the locked state of the first piston 11 is reliably maintained. Therefore, even if the pressure in the lock chamber 10 disappears, the locked state can be maintained.

When switching the clamping device from the locked state of FIG. 3 to the released state of FIG. Then, first, the second piston 12 descends with respect to the first piston 11, and then the first piston 11 strongly raises the clamp rod 32 with its rod portion 11a.

Here, if the shape of the workpiece W to be clamped causes the air discharge hole 40 to come off from the workpiece W and the air discharge hole 40 cannot be closed by the lower surface of the workpiece W, the bolt 31 is removed. The annular member 30 is rotated with respect to the housing 2 to adjust the circumferential position of the air discharge hole 40 so that the air discharge hole 40 can be closed with the lower surface of the workpiece W. After that, the annular member 30 is fixed to the housing 2 with bolts 31 . As a result, the lower surface of the workpiece W can close the air discharge hole 40 in the locked state of FIG.

2A shows a screw hole 2b formed in the housing 2 into which the bolt 31 is screwed, and FIG. 2B shows a bolt hole 30b formed in the annular member 30 into which the bolt 31 is inserted. Now, the annular member 30 is fixed to the end of the housing 2 on the release side with four bolts 31 . Therefore, the circumferential position of the air discharge hole 40 can be adjusted every 90 degrees. It should be noted that the air passage 44 formed inside the housing 2 is aligned with the groove 42 formed in the lower surface 30a of the annular member 30 regardless of the position in the circumferential direction of the air discharge hole 40 that can be adjusted every 90°. communicate with.

FIG. 4 shows a second embodiment of the invention. The differences between the second embodiment and the first embodiment are as follows.

In the second embodiment, the annular member 30 is fixed to the end of the housing 2 on the release side by frictional force using a plurality of pressing plates 45 as pressing members. Specifically, for example, the configuration is as follows.

A collar portion 30 c is formed on the outer peripheral edge portion of the annular member 30 . The pressing surface 45a of the pressing plate 45 is brought into contact with the upper surface of the flange portion 30c from above. Then, the annular member 30 is pressed against the housing 2 by screwing the bolt 31 inserted into the bolt hole 45 b formed in the pressing plate 45 into the housing 2 . A gap G is formed between the lower surface of the pressing plate 45 and the upper surface of the housing 2, whereby the annular member 30 is strongly fixed to the housing 2 using frictional force. can do.

Instead of using a plurality of pressing plates 45, the pressing member for fixing the annular member 30 may use a single annular pressing plate.

Furthermore, the pressing plate 45 is omitted, a bolt longer than the bolt 31 shown in FIG. 2, the annular member 30 may be fixed to the housing 2 using frictional force. In this case, the bolt becomes a pressing member. It should be noted that the original function of the bolt is to fasten members together by screwing the bolts together. The annular member 30 can be pressed and fixed more firmly against the .

In the first embodiment, the circumferential position of the air ejection holes 40 can be adjusted in steps of 90 degrees. On the other hand, in the second embodiment, the circumferential positions of the air ejection holes 40 can be adjusted more finely, for example, every 1°.

Also, in the first embodiment, the air supply port 43 for supplying compressed air to the air discharge hole 40 is provided on the side surface of the housing 2 . In the second embodiment, instead of this, an air supply port 46 for supplying compressed air to the air discharge holes 40 is provided on the surface of the housing 2 that contacts the upper surface of the clamp pallet 1 .

The above embodiment can be modified as follows.
In the above embodiment, the groove 42 extending in the circumferential direction is formed on the annular member 30 side, but the housing 2 side, that is, the surface of the housing 2 facing the annular member 30, for example, the upper surface 2c of the housing 2 (Fig. 1) may be formed with a circumferentially extending groove that allows the air passage 44 and the air passage 41 to communicate with each other. Furthermore, circumferentially extending grooves may be formed on both the annular member 30 side and the housing 2 side to allow the air passages 44 and 41 to communicate with each other.

Further, instead of forming the groove 42 extending in the circumferential direction in the lower surface 30a of the annular member 30, a groove extending in the circumferential direction is formed in the side surface of the annular member 30 to allow the air passage 44 and the air passage 41 to communicate with each other. may The same applies to the housing 2 side. If a groove extending in the circumferential direction for communicating the air passage 44 and the air passage 41 is formed in the housing 2 side, the housing 2 faces the annular member 30 instead of the upper surface 2 c of the housing 2 . A groove extending in the circumferential direction may be formed on the inner surface of the upper end of 2 .

In the embodiment described above, as shown in FIG. 2B, the groove 42 is formed over a range of approximately 270° around the axial direction of the annular member 30 . The extent of the groove 42 may be 180°, 90°, or even 360° (full circumference) around the axial direction, and is not limited to about 270°. do not have.

The air discharge hole 40 formed in the annular member 30 is a hole for detecting whether the workpiece W is seated on the seating surface S or not. Instead of this application, the air discharge hole 40 may be used as a hole for blowing off dust or the like adhering to the work piece W with compressed air (air blow). Furthermore, the discharge hole 40 may be used as a hole for discharging liquid for cleaning the workpiece W or the like. In this case, the discharge hole 40 is not an air discharge hole but a liquid discharge hole. Similarly, the supply port 43 provided in the housing 2 is not an air supply port but a liquid supply port.

FIG. 5 is a view corresponding to FIG. 2B showing a modification of the annular member 30. As shown in FIG. In the embodiment described above, the groove 42 that connects the first fluid passage and the second fluid passage is a groove extending in the circumferential direction. Alternatively, a groove having a diameter larger than the diameter of the first fluid passage or the diameter of the second fluid passage (for example, grooves 51, 54, and 55 shown in FIG. 5) may be used to separate the first fluid passage and the second fluid passage. may be communicated.
Although the embodiment shown in FIGS. 1 to 4 has one fluid ejection hole, in the modification shown in FIG. 5, the annular member 30 has a plurality of fluid ejection holes 40, 40a, and 40b. In this case, even if one of the plurality of discharge holes 40 is clogged with dust such as chips, it can be replaced by another discharge hole (eg, discharge hole 40b). It should be noted that the diameter of the discharge hole 40b is larger than the diameter of the discharge hole 40 in this modification. In place of the discharge holes 40 and 40b through which compressed air is discharged upward, a discharge hole 40a through which compressed air is discharged toward the clamp rod 32, the pressing member 33, and the like may be used.
Inside the annular member 30, second fluid passages 41, 52, 53 are formed that communicate with the fluid discharge holes 40, 40a, 40b, respectively. Grooves 51, 54, 55 formed in the lower surface of the annular member 30 communicate with the second fluid passages 41, 52, 53, respectively. The grooves 51 , 54 , 55 are, for example, hemispherical grooves, and their diameters are larger than the diameter of the first fluid passage 44 (see FIG. 1 etc.) formed in the housing 2 . With this configuration, by rotating the annular member 30, it is possible to change the position of the fluid discharge hole while maintaining communication between the fluid supply port and the fluid discharge hole. Specifically, the circumferential position of the fluid discharge hole can be finely adjusted (changed) within the range of each of the hemispherical grooves 51, 54, and 55, and the circumferential position of the fluid discharge hole can be adjusted in units of 90°. can be changed.
As with the groove 42 extending in the circumferential direction, grooves having a diameter larger than the diameter of the fluid passage, such as the grooves 51 , 54 and 55 , may be formed on the housing 2 side instead of the annular member 30 side. Furthermore, it may be formed on both the annular member 30 side and the housing 2 side.
When the groove is formed on the housing 2 side, its diameter is made larger than the diameter of the second fluid passage formed in the annular member 30 .

The member for clamping the workpiece W may be one that uses a single annular collet instead of using a plurality of pressing members 33 .

The clamping device of the present invention is not limited to the use for clamping the work piece W, but can also be used for clamping work pallets, molds, attachments, and the like. A ball or the like can be used as a member for clamping an object to be clamped such as the workpiece W instead of the pressing member 33 and the collet.

The pressurized fluid for locking and releasing may be nitrogen gas or the like instead of compressed air, or liquid such as pressurized oil.

The drive means for moving the clamp rod 32 in the axial direction may not have the booster mechanism 20 . Further, instead of using two pistons such as the first piston 11 and the second piston 12, the driving means may be configured using one piston.

The clamping device may be arranged upside down or obliquely from the illustration.

The embodiments and modifications of the present invention have been described above. In addition, it is of course possible to make various modifications within the range that a person skilled in the art can assume.

2: housing, 2c: upper surface (opposing surface), 30: annular member, 30a: lower surface (opposing surface), 32: clamp rod, 40: air discharge hole (fluid discharge hole), 41: air passage (second fluid passage) ), 42: groove, 43: air supply port (fluid supply port), 44: air passage (first fluid passage), 45: holding plate (holding member), 46: air supply port (fluid supply port), 50: Drive Means 51: Groove 54: Groove 55: Groove

Claims (3)

a housing (2) provided with fluid supply ports (43, 46);
a clamping rod (32) inserted into said housing (2);
a driving means (50) for axially moving the clamp rod (32) between a lock side and a release side;
An annular member (30) fixed to the end of the housing (2) on the release side and into which the clamp rod (32) is inserted, and formed with a fluid discharge hole (40) for discharging fluid. an annular member (30);
with
A first fluid passage (44) communicating with the fluid supply ports (43, 46) is formed inside the housing (2),
A second fluid passage (41) communicating with the fluid ejection hole (40) is formed inside the annular member (30),
On at least one of a facing surface (30a) of the annular member (30) facing the housing (2) and a facing surface (2c) of the housing (2) facing the annular member (30), the A circumferentially extending groove (42 ) is formed to constantly communicate the first fluid passage (44) and the second fluid passage (41),
Screw holes (2b) into which bolts (31) for fixing the annular member (30) to the housing (2) are screwed are spaced at predetermined angles in the circumferential direction of the housing (2). is formed in the housing (2),
By rotating the annular member (30) with respect to the housing (2), the circumferential position of the fluid discharge hole (40) is adjusted for each of the predetermined angles.
clamping device. a housing (2) provided with fluid supply ports (43, 46);
a clamping rod (32) inserted into said housing (2);
a driving means (50) for axially moving the clamp rod (32) between a lock side and a release side;
An annular member (30) fixed to the end of the housing (2) on the release side and into which the clamp rod (32) is inserted, and formed with a fluid discharge hole (40) for discharging fluid. an annular member (30);
with
A first fluid passage (44) communicating with the fluid supply ports (43, 46) is formed inside the housing (2),
A second fluid passage (41) communicating with the fluid ejection hole (40) is formed inside the annular member (30),
On at least one of a facing surface (30a) of the annular member (30) facing the housing (2) and a facing surface (2c) of the housing (2) facing the annular member (30), the Circumferentially extending groove (42) connecting first fluid passage (44) and second fluid passage (41), or connecting first fluid passage (44) and second fluid passage (41) Grooves (51, 54, 55) having a larger diameter than the diameter of the first fluid passage (44) or the diameter of the second fluid passage (41) are formed for communication,
The annular member (30) is pressed against the housing (2) so that the circumferential position of the fluid discharge hole (40) can be adjusted at the release side end of the housing (2). A holding member (45) that fixes the member (30) by frictional force,
clamping device. The clamping device of claim 1, wherein
When viewed from the axial direction of the clamp rod (32), a bolt hole (30b) into which the bolt (31) is inserted, and the groove (42) or a virtual virtual groove extending in the circumferential direction. The bolt hole (30b) is formed in the annular member (30) so that the groove portion and the groove portion overlap each other,
clamping device.

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