Swivel clamp

Abstract

A compact swing clamp device is provided which is durable and compact. A large-diameter hole (6) and a medium-diameter hole (7) are formed in a housing body (2) in series from the lower side in the axial direction. A cylindrical protruding member (3) is inserted into the large-diameter hole (6) in a sealed manner and is screwed to the housing body (2). A key member (22) is inserted between a cylindrical retainer (15) inserted into the medium-diameter hole (7) and the medium-diameter hole (7). The retainer (15) is positioned in the circumferential direction with respect to the housing body (2) by the key member (22).

Description

Technical Field

[0001] This invention relates to a rotary clamping device that uses a clamping arm to fix workpieces, molds, tools, etc., onto a worktable, robot arm, etc. by rotating and lowering the clamping arm. Background Technology

[0002] In this type of rotary clamping device, there is a prior art device described in Patent Document 1 (Japanese Utility Model Application Publication No. 5-52304). Its prior art is configured as follows.

[0003] In the rotary clamping device shown in Figure 5 of Patent Document 1, a piston is inserted into the bore of a cylinder tube. A cylindrical rod cover is inserted into the end of the bore of the cylinder tube, protruding upward from the cylinder tube. A piston rod, protruding from the piston towards its end, is inserted into the bore of the rod cover, protruding outward from the cylinder head. The rod cover is received from below by a stepped portion formed on the inner circumferential wall of the bore of the cylinder tube, and a retaining ring prevents it from falling out of the bore of the cylinder tube. Furthermore, a threaded hole extends radially through the cylinder wall of the cylinder tube, and a screw is screwed into this threaded hole. The end of the screw is inserted into a recess formed on the outer circumferential wall of the rod cover. Thus, rotation of the rod cover relative to the cylinder tube is prevented.

[0004] In addition, in Patent Document 1 Figure 1 In the rotary clamping device, instead of the aforementioned retaining ring, the rod cover is fixed to the cylinder tube using a ring nut.

[0005] Prior art literature

[0006] Patent documents

[0007] Patent Document 1: Japanese Utility Model Application Publication No. 5-52304 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] The aforementioned prior art has the following problems.

[0010] A retaining ring installed between the cylinder tube and the rod cover, on the inner circumferential wall of the cylinder tube, prevents the rod cover from detaching from the cylinder tube. To install this retaining ring between the cylinder tube and the rod cover, spaces are needed for inserting the retaining ring, for insertion work, and for inserting installation tools. Therefore, the radial dimension of the cylinder tube increases. Furthermore, when the piston reaches its final extreme position, the screw and retaining ring absorb the impact caused by the collision between the piston and the rod cover. To form a structure resistant to this impact, in addition to measures such as maximizing the screw diameter or increasing the number of thread turns to prevent loosening, the thickness and width of the retaining ring also need to be increased to improve durability. Therefore, the cylinder tube wall needs to be sufficiently thick. Consequently, the radial dimension of the rotary clamping device increases.

[0011] In addition, in Patent Document 1 Figure 1 In the rotary clamping device shown, a ring nut is installed from above between the outer circumferential surface of the rod cover and the inner circumferential surface of the cylinder tube. Therefore, spaces are needed for inserting the ring nut between the cylinder tube and the rod cover, as well as for inserting a tool. Consequently, the radial dimension of the rotary clamping device becomes larger.

[0012] The purpose of this invention is to provide a durable and compact rotary clamping device.

[0013] Solution for solving the problem

[0014] To achieve the above objectives, the present invention, for example, Figure 1 and Figure 2 As shown, the rotary clamping device is configured as follows.

[0015] A large-diameter hole 6, a medium-diameter hole 7, and a small-diameter hole 8 are sequentially formed within the housing body 2 from the axial end side to the base end side. A cylindrical protruding member 3 is inserted into the large-diameter hole 6 in a sealing manner. An external thread 11 formed on the outer peripheral wall of the protruding member 3 engages with an internal thread 10 formed on the inner peripheral wall of the medium-diameter hole 7. A cylindrical retainer 15 is inserted into the medium-diameter hole 7. A first keyway 20 is formed along the axial direction on the inner peripheral wall of the medium-diameter hole 7. A second keyway 21, facing the first keyway 20, is formed along the axial direction on the outer peripheral wall of the retainer 15. A key member 22 is installed between the first keyway 20 and the second keyway 21. A piston 25 is inserted into the small-diameter hole 8 in a sealing manner, movable along the axial direction. A piston rod 30, protruding from the piston 25 towards the axial end side, protrudes outward from the protruding member 3 through the cylindrical hole 31 of the retainer 15 and the cylindrical hole 19 of the protruding member 3. The engaging member 38 protrudes radially inward from the inner circumferential surface of the retainer 15. The engaging member 38 is inserted into the spiral groove 39 and the straight groove 40, which are sequentially formed on the outer circumferential wall of the piston rod 30 from the base end side in the axial direction. A portion of the peripheral wall of the first keyway 20 is formed to be radially outward from the inner circumferential surface of the large-diameter hole 6.

[0016] The present invention achieves the following effects.

[0017] Since the aforementioned protruding member is directly and securely screwed onto the housing body via external and internal threads, the durability of the engagement portion between the protruding member and the housing body can be improved. Furthermore, since no additional component is required to connect the protruding member to the housing body, the rotary clamping device can be made smaller. Attached Figure Description

[0018] Figure 1 The diagram illustrates one embodiment of the present invention and is a cross-sectional schematic of a rotary clamping device.

[0019] Figure 2 This is a diagram showing the clamping state of the aforementioned rotary clamping device.

[0020] Figure 3 It is a diagram showing the exploded state of the shell, protruding members, retainers, and key members. Detailed Implementation

[0021] The following uses Figure 1 , Figure 2 and Figure 3 The embodiments of the present invention are described below.

[0022] The housing 1 of the aforementioned rotary clamping device has a housing body 2, a protruding member 3, and a cover member 4. The housing body 2 is made of an aluminum drawing member. A cylinder bore 5 is formed inside the housing body 2. The cylinder bore 5 has a large-diameter bore 6, a medium-diameter bore 7, and a small-diameter bore 8 formed sequentially from the top side (the axial end side).

[0023] The lower part of the protruding member 3 is inserted into the aforementioned large-diameter hole 6. An internal thread portion 10 is formed in the upper half of the aforementioned intermediate-diameter hole 7, and an external thread portion 11 formed on the protruding member 3 is screwed into the internal thread portion 10. Therefore, the protruding member 3 is fixed to the housing body 2 in a state of protruding upward from the housing body 2. A receiving groove 12 is formed circumferentially on the upper side of the external thread portion 11 of the protruding member 3, and a sealing member 13 such as an O-ring is installed in the receiving groove 12. By the state in which the protruding member 3 is screwed into the housing body 2, the sealing member 13 is pressed against the sealing surface formed by the inner circumferential surface of the large-diameter hole 6, and the inner circumferential surface of the large-diameter hole 6 and the outer circumferential surface of the protruding member 3 are sealed.

[0024] Insert a cylindrical retainer 15 into the lower half of the aforementioned intermediate diameter hole 7 (see reference). Figure 3 (A, B) The retainer 15 is received from below by a stepped portion 16 formed between the small-diameter hole 8 and the intermediate-diameter hole 7. The retainer 15 has a large-diameter portion 17 and a small-diameter portion 18 formed sequentially from the bottom side. The small-diameter portion 18 is inserted into the cylindrical hole 19 of the protruding member 3. In addition, a first keyway 20 is formed in the vertical direction on the inner peripheral wall of the intermediate-diameter hole 7, and a second keyway 21 is formed on the outer peripheral wall of the large-diameter portion 17 of the retainer 15 at a position facing the first keyway 20. The deepest part of the bottom surface of the first keyway 20 is set to be radially outward than the inner peripheral surface of the large-diameter hole 6. In addition, a parallel pin (see reference) serving as a key member 22 is installed between the first keyway 20 and the second keyway 21 with a sliding gap. Figure 3 B). A through groove 23, continuous with the second keyway 21, is provided on the small diameter portion 18 side of the retainer 15, allowing the key member 22 to easily enter. Thus, the retainer 15 is positioned circumferentially relative to the housing body 2, and rotation is prevented.

[0025] In the aforementioned small-diameter bore 8, the piston 25 is inserted in a sealed manner and in a way that allows it to move vertically (axially in the cylinder bore 5). A clamping chamber 26 is formed on the upper side of the piston 25, and a release chamber 27 is formed on the lower side of the piston 25. Furthermore, a clamping supply / discharge port 28 for supplying and discharging compressed air from a compressed air source is formed in the main body of the housing body 2, and this clamping supply / discharge port 28 communicates with the clamping chamber 26. A release supply / discharge port 29 is formed on the lower side of the clamping supply / discharge port 28 and in the main body of the housing body 2, and this release supply / discharge port 29 communicates with the release chamber 27.

[0026] A piston rod 30 protrudes upward from the piston 25 and is inserted into the cylindrical hole 31 of the retainer 15, and is also inserted into the cylindrical hole 19 of the protruding member 3 in a sealed manner and in a manner that allows it to move vertically. The piston rod 30 protrudes outward from the protruding member 3. One end 33a of a clamping arm 33 is threadedly fixed to the end of the piston rod 30. A pressing part 34 is formed on the back of the other end 33b of the clamping arm 33, which can abut against the workpiece (fixed object) 35.

[0027] A spherical engaging ball (engaging member) 38 is installed in the recess 37 formed on the inner peripheral wall of the retainer 15. The engaging ball 38 protrudes radially inward from the inner peripheral surface of the retainer 15. The engaging ball 38 is inserted into the spiral groove 39 and the straight groove 40 formed sequentially from the bottom on the outer peripheral wall of the piston rod 30.

[0028] A step portion 41 is formed circumferentially on the outer peripheral wall of the piston rod 30, above the spiral groove 39. A protrusion 42 protrudes radially inward from the inner peripheral surface of the bore 19 of the protruding member 3. A receiving groove 43 is formed circumferentially on the inner peripheral wall of the bore 19, below the protrusion 42. An impact-absorbing member 44, such as a rubber, resin, or metal spring, is installed in the receiving groove 43. When the piston rod 30 moves to its upper limit position, the step portion 41 of the piston rod 30 is received by the protrusion 42 of the protruding member 3 via the impact-absorbing member 44.

[0029] like Figure 1 and Figure 2 As shown, the rotary clamping device operates as follows.

[0030] exist Figure 1 In the initial state (release state), compressed air (pressure fluid) is discharged from the clamping chamber 26, and compressed air (pressure fluid) is supplied to the release chamber 27. The piston 25 and piston rod 30 move to the upper limit position through the compressed air in the release chamber 27, and the engagement portion formed on the step portion 41 of the piston rod 30 is received from above by the impact absorption member 44.

[0031] When from Figure 1 Switching to the release state Figure 2In the clamping state, firstly, the compressed air in the release chamber 27 is discharged to the outside through the release supply port 29, and compressed air from the compressed air source is supplied to the clamping chamber 26 through the clamping supply port 28. The piston 25 moves downwards through the compressed air in the clamping chamber 26, rotating clockwise as it moves downwards via the spiral groove 39 and the engaging ball 38 when viewed from above. Next, the piston 25 moves vertically downwards via the straight groove 40 and the engaging ball 38. The clamping arm 33 presses down on the workpiece 35 placed on the worktable T from above, stopping the descent of the piston 25. Thus, the rotary clamping device... Figure 1 Switching to the release state Figure 2 The clamped state.

[0032] When from Figure 2 Switching to clamping state Figure 1 In the released state, compressed air in clamping chamber 26 is discharged, and compressed air is supplied to release chamber 27. The compressed air in release chamber 27 then causes piston 25 and piston rod 30 to move vertically upwards. Next, clamping arm 33 moves upwards while rotating counterclockwise when viewed from above. The engagement portion of piston rod 30 is received from above by the impact-absorbing member 44 of protruding member 3, stopping the upward movement of piston rod 30. Thus, the rotary clamping device... Figure 2 Switching to clamping state Figure 1 The released state.

[0033] The above-described embodiments have the following advantages.

[0034] Since the protruding member 3 is directly and securely screwed into the housing body 2 via its internal thread 10 and the external thread 11 of the housing body 2, there is no need for additional components for connecting the protruding member 3 and the housing body 2. This allows for a reduction in the radial dimensions of the housing body 2 and the protruding member 3. Consequently, the rotary clamping device can be made smaller.

[0035] like Figure 1 and Figure 2 As shown, when the rotary clamping device is viewed in cross-section, the bottom surface of the first keyway 20 is formed to be radially outer than the inner circumferential surface of the large-diameter hole 6 of the housing body 2. Therefore, the key member 22 is evenly positioned across the aforementioned radial outer and inner sides, with the inner circumferential surface of the large-diameter hole 6 abutting the housing body 2 and the protruding member 3. This allows for a smaller thickness of the cylinder wall of the housing body 2 and the cylinder wall of the retainer 15, thus enabling a smaller radial dimension of the housing body 2 and the retainer 15. Consequently, the overall size of the rotary clamping device can be made smaller.

[0036] As the piston 25 and piston rod 30 move vertically, the peripheral wall of the helical groove 39 of the piston rod 30 presses the retainer 15 circumferentially via the engaging ball 38. The retainer 15 is reliably received by the housing body 2 via the key member 22, preventing rotation. Therefore, the pressing force is difficult to transmit circumferentially to the protruding member 3, which is a different component from the retainer 15. Thus, loosening of the threaded portion caused by circumferential pressing force acting on the threaded portion between the housing body 2 and the protruding member 3 can be prevented. Therefore, wear and damage to the threaded portion and its surrounding components caused by loosening can be prevented, improving the durability of the rotary clamping device.

[0037] The internal thread portion 10 has multiple threaded grooves formed around the center diameter hole 7 of the housing body 2. Compared with the threaded grooves of the threaded holes formed on the cylinder wall in the conventional rotary clamping device, the threaded grooves of the internal thread portion 10 of the present invention are longer. Therefore, by engaging the internal thread portion 10 with the external thread portion 11 of the protruding member 3 through a large-area engagement portion, a large frictional force can be applied to the engagement portion. Therefore, even if the piston rod 30 impacts the engagement portion when colliding with the protruding member 3, loosening of the engagement portion can be prevented. Therefore, wear and damage to the engagement portion and its surrounding components caused by loosening can be prevented, thereby improving the durability of the rotary clamping device.

[0038] The above-described embodiments can be modified as follows.

[0039] The pressure fluid may also replace the compressed air exemplified by other gases or liquids such as pressurized oil and water.

[0040] The aforementioned housing body 2 can also be made of other metals, such as iron or other materials, instead of aluminum. The housing body 2 is not limited to drawn parts; it can also be a component formed by machining.

[0041] Alternatively, the protruding member 3 can be screwed onto the housing body 2, allowing the protruding member 3 to be received by the stepped portion 16 of the housing body 2 via the retainer 15, or by the housing body 2 (lower end wall of the first keyway 20) via the key member 22, or directly received by the housing body 2. In this case, a gap is formed between the protruding member 3 and the retainer 15. As a result, by the upward and downward movement of the piston 25, the peripheral wall of the spiral groove 39, via the engaging ball 38, makes it difficult for the pressing force exerted by the retainer 15 in the axial direction to be transmitted to the protruding member 3. Consequently, it is possible to prevent loosening of the screwed portion caused by circumferential pressing force acting on the screwed portion between the housing body 2 and the protruding member 3. Therefore, it is possible to prevent wear and damage caused by loosening, and improve the durability of the rotary clamping device.

[0042] The aforementioned engaging component can also replace the spherical engaging ball 38 with other components of roughly cylindrical, rectangular, or other shapes.

[0043] The aforementioned engaging member can also be provided instead of being provided on the retainer 15, but protruding from the outer peripheral wall of the piston rod 30. In this case, the straight groove and the spiral groove are provided on the peripheral wall of the retainer 15 in a sequential manner from the bottom (in a manner that penetrates the peripheral wall).

[0044] The key member 22 described above is not limited to being a cylindrical parallel pin; it can also be a polygonal pin or a spherical member. Furthermore, it is not limited to having only one key member 22; multiple key members 22 can be provided at predetermined intervals on the peripheral wall of the retainer.

[0045] The aforementioned impact-absorbing member 44 can also replace the protrusion 42 installed on the protruding member 3, and be installed on the inner peripheral wall of the large-diameter hole 6 of the housing body 2, the lower end of the retainer 15, the upper part of the piston 25, and the stepped part 41 of the piston rod 30.

[0046] Furthermore, various modifications can certainly be made within the scope that can be conceived by those skilled in the art.

[0047] Explanation of reference numerals in the attached figures

[0048] 2. Shell Body

[0049] 3 protruding components

[0050] 6 large diameter holes

[0051] 7 Medium Diameter Hole

[0052] 8 small diameter holes

[0053] 10 Internal thread section

[0054] 11 External thread section

[0055] 15 Retainers

[0056] 20 First key slot

[0057] 21 Second keyway

[0058] 22-key components

[0059] 25 piston

[0060] 30 piston rod

[0061] 31 cylinder holes

[0062] 19 cylinder holes

[0063] 38-card combination ball

[0064] 39 spiral grooves

[0065] 40 straight groove

Claims

1. A rotary clamping device, characterized in that, The rotary clamping device includes: Shell body (2); Large-diameter hole (6), medium-diameter hole (7) and small-diameter hole (8) are formed sequentially from the end side to the base side in the housing body (2); A cylindrical protruding member (3) is inserted into the large-diameter hole (6) in a sealed manner and protrudes from the housing body (2) toward the axial end side; An external thread (11) is formed on the outer peripheral wall of the protruding member (3) and engages with an internal thread (10) formed on the inner peripheral wall of the middle diameter hole (7); A cylindrical retainer (15) is inserted into the middle diameter hole (7); A first keyway (20) is formed along the axial direction on the inner peripheral wall of the intermediate diameter hole (7); The second keyway (21) is formed along the axial direction on the outer peripheral wall of the retainer (15) in a manner that faces the first keyway (20); Key component (22) is installed between the first keyway (20) and the second keyway (21); The piston (25) is inserted into the small-diameter hole (8) in a sealed manner, movable along the axial direction. The piston rod (30) is provided to protrude from the piston (25) toward the axial end side, and protrudes outward from the protruding member (3) through the retainer cylinder hole (31) of the retainer (15) and the protruding member cylinder hole (19) of the protruding member (3); The engaging member (38) protrudes radially inward from the inner circumference of the retainer (15); and Spiral grooves (39) and straight grooves (40) are sequentially formed on the outer peripheral wall of the piston rod (30) from the base end side of the axial direction and are for the insertion of the engaging member (38). A portion of the peripheral wall of the first keyway (20) is formed to be radially outward from the inner peripheral surface of the large-diameter hole (6).

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