Clamping device

Abstract

To provide a clamp device which can fix a small and thin work and can be miniaturized.SOLUTION: The clamping device includes an accommodation portion capable of accommodating a protrusion protruding from a main surface of the workpiece, an engagement portion provided in the accommodation portion and configured to engage with the protrusion while plastically deforming an outer peripheral surface of the protrusion, and a main body including a cylinder drive unit configured to engage the protrusion and the engagement portion with each other and move the engagement portion along the first direction in a state where the protrusion and the engagement portion are engaged with each other.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present technology relates to clamping devices. [Background technology]

[0002] Japanese Patent Laid-Open Publication No. 09-285925 (Patent Document 1) describes a clamping device that fixes a workpiece via a pull bolt fixed to the underside of the workpiece.

[0003] International Publication No. 2004 / 091853 (Patent Document 2) describes a clamping device that secures a pallet via a nipple fixed to the underside of the pallet.

[0004] Japanese Patent Application Laid-Open Publication No. 2011-201008 (Patent Document 3) describes a clamping device equipped with a gripping member capable of gripping the inner peripheral surface of a hole provided in the lower surface of a workpiece.

[0005] Japanese Patent Application Laid-Open No. 2007-237339 (Patent Document 4) describes a chuck capable of fixing a shaft portion. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 09-285925 [Patent Document 2] International Publication No. 2004 / 091853 [Patent Document 3] Japanese Patent Application Laid-Open No. 2011-201008 [Patent Document 4] Japanese Patent Application Laid-Open No. 2007-237339 Summary of the Invention [Problem to be solved by the invention]

[0007] In the clamping devices described in Patent Documents 1 and 2, it is necessary to fix a pull bolt or nipple to the underside of the workpiece. In addition, in the clamping device described in Patent Document 3, it is necessary to provide a fixing hole on the underside of the workpiece. From the viewpoint of being able to handle smaller and thinner workpieces, there is still room for improvement in conventional clamping devices.

[0008] The chuck described in Patent Document 4 has a complex structure, and there are many restrictions on making it smaller.

[0009] One object of the present technology is to provide a clamping device capable of fixing a small and thin workpiece, and from another perspective, to provide a clamping device that can be made smaller. [Means for solving the problem]

[0010] The present technology provides the following clamping device.

[0011] [1] A clamping device comprising: a housing portion capable of housing a protrusion protruding from a main surface of a workpiece; an engaging portion provided in the housing portion and engaging with the protrusion while plastically deforming the outer peripheral surface of the protrusion; and a main body including a cylinder driving portion that engages the protrusion with the engaging portion and moves the engaging portion along a first direction while the protrusion and the engaging portion are engaged.

[0012] [2] The clamping device described in [1], wherein the main body includes a first part capable of driving the engaging part in the first direction and a second direction perpendicular to the first direction, and a second part that holds the engaging part movably in the second direction, and while holding the second part in the first direction, the cylinder driving part drives the first part in the first direction to engage the engaging part with the outer peripheral surface of the protrusion, and the cylinder driving part drives the first part in the first direction with the engaging part engaged with the outer peripheral surface of the protrusion, thereby moving the first part, the engaging part, and the second part along the first direction. [3] A clamping device as described in [2], wherein when the engaging portion is engaged with the outer peripheral surface of the protrusion, the first portion is urged in the first direction by a first urging force, and the second portion is urged in the opposite direction to the first portion by a second urging force, and the first urging force is greater than the second urging force.

[0013] [4] The clamping device described in [2], wherein the cylinder driving unit includes a first cylinder chamber that urges the first portion in the first direction, and a second cylinder chamber that communicates with the first cylinder chamber and urges the second portion in the opposite direction to the first portion, and the urging force of the first cylinder chamber is greater than the urging force of the second cylinder chamber.

[0014] [5] A clamping device described in any one of [1] to [4], further comprising a positioning surface facing the main surface of the workpiece and an air passage opening to the positioning surface, and configured to be able to detect that the main surface of the workpiece has come into contact with the positioning surface based on an increase in air pressure in the air passage.

[0015] [6] A clamping device according to any one of [1] to [5], wherein the engaging portion includes a plurality of steel balls.

[0016] [7] A clamping device described in any one of [2] to [6], wherein the first part of the main body abuts the engagement portion and includes an inclined surface that inclines so as to approach the axis of the protrusion as it approaches the main surface of the workpiece. [Effects of the Invention]

[0017] According to the present technology, it is possible to provide a clamping device that can fix a small and thin workpiece, and from another perspective, it is possible to provide a clamping device that can be made smaller. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a cross-sectional view showing a first state (clamped state) of a clamping device according to one embodiment. [Figure 2] 2A and 2B are cross-sectional views of the clamping device shown in FIG. 1 taken in a different direction. [Figure 3] 4 is a cross-sectional view showing a second state (unclamped state) of the clamping device according to one embodiment. FIG. [Figure 4] 4 is a cross-sectional view showing a state in which a workpiece is not placed on the clamp device shown in FIGS. 1 to 3 and a working medium is supplied to a cylinder chamber on the clamp side. FIG. [Figure 5] FIG. 10 is a cross-sectional view showing a first state (clamped state) of a clamping device according to one modified example. [Figure 6] FIG. 10 is a cross-sectional view showing a first state (clamped state) of a clamping device according to another modified example. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, embodiments of the present technology will be described. Note that the same or corresponding parts are denoted by the same reference characters, and description thereof may not be repeated.

[0020] In the embodiments described below, when numbers, amounts, etc. are mentioned, the scope of the present technology is not necessarily limited to those numbers, amounts, etc., unless otherwise specified. Furthermore, in the following embodiments, each component is not necessarily essential to the present technology, unless otherwise specified. Furthermore, the present technology is not necessarily limited to those that achieve all of the effects and advantages mentioned in the present embodiments.

[0021] In this specification, the terms "comprise," "include," and "have" are open-ended. That is, when a certain feature is included, other features may or may not be included.

[0022] Furthermore, when geometric terms and terms expressing positional and directional relationships are used in this specification, such as "parallel," "orthogonal," "45° diagonal," "coaxial," and "along," these terms allow for manufacturing errors and slight variations. When terms expressing relative positional relationships, such as "upper side" and "lower side," are used in this specification, these terms are used to indicate relative positional relationships in a single state, and the relative positional relationships can be reversed or rotated to any angle depending on the installation direction of each mechanism (for example, by turning the entire mechanism upside down).

[0023] In this specification, each configuration may be assigned an ordinal number such as "first" or "second," but these ordinal numbers do not limit the priority, order, etc. unless explicitly specified.

[0024] 1 is a cross-sectional view showing a first state (clamped state) of a clamping device according to this embodiment. The clamping device 1 is for fixing a workpiece 2. The clamping device 1 is provided on a base 3.

[0025] The clamping device 1 includes a main body 100 including a cylinder drive unit, a storage section 200 capable of storing a protrusion 2A of the workpiece 2, and an engagement section 300 provided in the storage section 200. The workpiece 2 has a main surface 2B (back surface) facing the clamping device 1, and the protrusion 2A protrudes from the main surface 2B toward the clamping device 1 (the lower side in FIG. 1). This embodiment relates to a clamping method for clamping the workpiece 2 by fixing the protrusion 2A integrally molded with the main body of the workpiece 2, and to a clamping device 1 used therefor.

[0026] The engaging portion 300 engages with the protrusion 2A while plastically deforming the outer peripheral surface of the protrusion 2A. In this embodiment, the engaging portion 300 includes a plurality of steel balls arranged to surround the outer periphery of the protrusion 2A. However, the engaging portion 300 is not limited to one including steel balls, and for example, a substantially cylindrical engaging tool may also be used.

[0027] The cylinder drive unit of the main body 100 engages the protrusion 2A of the workpiece 2 with the engagement unit 300, and can move the engagement unit 300 along the vertical direction (first direction) in Figure 1 while the protrusion 2A and the engagement unit 300 are engaged.

[0028] The following describes the configuration of the main body 100. The main body 100 includes a first piston member 110 (first portion), a second piston member 120 (second portion), a third piston member 130 (first portion), a cylinder main body 140, a cap member 150 (bottom member), and a cylinder chamber 160 (cylinder drive portion).

[0029] The cap member 150 has a rod portion 151 that extends in the vertical direction (first direction) inside the cylinder body 140. A step surface 152 is formed on the rod portion 151. The cylinder chamber 160 has a first cylinder chamber 161, a second cylinder chamber 162, and a third cylinder chamber 163.

[0030] The first piston member 110 (driving piston member) fits into the cylinder body 140. The first piston member 110 separates a first cylinder chamber 161 (clamping chamber) and a third cylinder chamber 163 (unclamping chamber). The first piston member 110 has an inclined surface 111 that abuts against the engaging portion 300 and a communication passage 112 that connects the first cylinder chamber 161 and the second cylinder chamber 162. The inclined surface 111 is tapered so that the opening of the first piston member 110 narrows in diameter as it approaches the main surface 2B of the workpiece 2 (so that the inclined surface 111 approaches the axis of the protrusion 2A). The intersection angle (inclination angle) of the inclined surface 111 with the axis of the protrusion 2A is, for example, approximately 3° or more (more preferably approximately 5° or more) and approximately 15° or less, but is not limited to this. The inclined surface 111 is not limited to a flat surface, and may have a curved shape with a varying inclination angle.

[0031] The upper part of the second piston member 120 (retaining sleeve member) fits into the inner circumferential surface of the first piston member 110. The lower part of the second piston member 120 fits into the inner circumferential surface of the third piston member 130. The outer circumferential surface of the rod portion 151 fits into the inner circumferential surface of the second piston member 120.

[0032] The second piston member 120 has a holding portion 121 that holds the engaging portion 300. The holding portion 121 holds the engaging portion 300 so that it can move in the radial direction (second direction) of the protrusion 2A. The second piston member 120 faces the second cylinder chamber 162 and also faces the third cylinder chamber 163. The second piston member 120 has a stepped surface 122 that faces the stepped surface 152 of the cap member 150.

[0033] The third piston member 130 is fitted between the inner circumferential surface of the first piston member 110 and the outer circumferential surface of the second piston member 120. The third piston member 130 is fixed to the first piston member 110 and reciprocates integrally with the first piston member 110. The third piston member 130 is slidable relative to the second piston member 120.

[0034] A second cylinder chamber 162 is formed between the second piston member 120 and the third piston member 130. The second cylinder chamber 162 communicates with the first cylinder chamber 161 via a communication passage 112.

[0035] The cylinder body 140 has a positioning surface 141 facing the main surface 2B of the workpiece 2, and flow paths 142A and 142B (working medium paths). The clamping device 1 can position the workpiece 2 in the vertical direction by bringing the main surface 2B of the workpiece 2 into contact with the positioning surface 141.

[0036] The flow paths 142A and 142B are connected to a first cylinder chamber 161 (clamping chamber) and a third cylinder chamber 163 (unclamping chamber), respectively. A working medium for the clamp device 1 is supplied to the flow paths 142A and 142B from flow paths 3A and 3B of the base 3. The working medium may be hydraulic oil or air.

[0037] When the working medium is supplied to the first cylinder chamber 161 via the flow path 3A and the flow path 142A and the first piston member 110 is urged downward in Fig. 1, as the first piston member 110 moves downward, the engaging portion 300 is pushed by the inclined surface 111 and moves radially inward toward the protrusion 2A. In this way, the first piston member 110 can drive the engaging portion 300 in the radial direction of the protrusion 2A.

[0038] At this time, the working medium is also supplied to the second cylinder chamber 162 via the communication passage 112, and the second piston member 120 is biased in the opposite direction to the first piston member 110 (upward in FIG. 1). Therefore, the second piston member 120 and the engaging portion 300 are held in the up-down direction. In this state, the engaging portion 300 can be driven in the radial direction of the protrusion 2A to engage with the outer peripheral surface of the protrusion 2A. At this time, the outer peripheral surface of the protrusion 2A is plastically deformed.

[0039] When the engaging portion 300 engages with the protrusion 2A, the first piston member 110, the second piston member 120, the engaging portion 300, and the workpiece 2 move integrally in the vertical direction. In this state, the first cylinder chamber 161 further biases the first piston member 110.

[0040] At this time, the second piston member 120 (second portion) is urged by the second cylinder chamber 162 in the opposite direction (upward in FIG. 1) to the first piston member 110, and at the same time, the third piston member 130 (first portion) is urged by the second cylinder chamber 162 in the opposite direction to the second piston member 120. In the example of FIG. 1, the areas of the second piston member 120 and the third piston member 130 that receive pressure from the second cylinder chamber 162 are the same. Furthermore, in the example of FIG. 1, the area of ​​the first piston member 110 (first portion) that receives pressure from the first cylinder chamber 161 is larger than the area of ​​the second piston member 120 (second portion) that receives pressure from the second cylinder chamber 162. In this way, the downward biasing force (first biasing force) applied by the first cylinder chamber 161 and the second cylinder chamber 162 to the first piston member 110 and the third piston member 130 (the two members together form the first part) is greater than the upward biasing force (second biasing force) applied by the second cylinder chamber 162 to the second piston member 120 (the second part). Therefore, when the engaging part 300 is engaged with the protrusion 2A, the first piston member 110, the second piston member 120 and the engaging part 300 are driven downward together with the workpiece 2.

[0041] The areas of the second piston member 120 and the third piston member 130 that receive pressure from the second cylinder chamber 162 do not necessarily have to be the same. Furthermore, the area of ​​the first piston member 110 that receives pressure from the first cylinder chamber 161 does not necessarily have to be larger than the area of ​​the second piston member 120 that receives pressure from the second cylinder chamber 162. In a structure in which the first cylinder chamber 161 and the second cylinder chamber 162 are connected to each other, if the sum of the pressure receiving areas of the first piston member 110 and the third piston member 130 is larger than the pressure receiving area of ​​the second piston member 120, the above-mentioned relationship holds true: the downward biasing force (first biasing force) is larger than the upward biasing force (second biasing force).

[0042] Fig. 2 is a cross-sectional view of the clamping device 1 shown in Fig. 1 in a different direction. As shown in Fig. 2, the cylinder body 140 is fixed to the base 3 by a bolt 400.

[0043] The cylinder body 140 also has an air passage 142C that opens to the positioning surface 141. Pressurized air is supplied to the air passage 142C from the air passage 3C of the base 3. When the main surface 2B of the workpiece 2 abuts against the positioning surface 141 of the cylinder body 140, the opening of the air passage 142C is closed, and the air pressure in the air passage 142C increases. This increase in air pressure can be detected using known means.

[0044] In this way, in the clamping device 1, based on the increase in air pressure in the air passage 142C, it is possible to detect that the main surface 2B of the workpiece 2 has come into contact with the positioning surface 141 and that the clamping and positioning of the workpiece 2 has been completed successfully.

[0045] As shown in FIGS. 1 and 2, seal members are provided at portions that seal the flow paths 142A and 142B, the air passage 142C, the first cylinder chamber 161, the second cylinder chamber 162, and the third cylinder chamber 163, respectively.

[0046] FIG. 3 is a cross-sectional view showing the second state (unclamped state) of the clamping device 1 shown in FIGS.

[0047] The working medium is supplied to the third cylinder chamber 163 via the flow path 3B and the flow path 142B, and the first piston member 110 is urged upward in FIG. 3. At this time, the second piston member 120 is also urged upward by the third cylinder chamber 163. As a result, the first piston member 110, the second piston member 120, and the third piston member 130 return to the states they were in before the clamp drive, and the engagement between the engagement portion 300 and the protrusion 2A is released.

[0048] FIG. 4 shows a state in which the workpiece 2 is not placed in the clamping device 1 shown in FIGS. 1 to 3 and the working medium is supplied via the flow path 142A.

[0049] At this time, the second piston member 120 is pushed downward by the first piston member 110. When it has moved to the lowest position, the first piston member 110 abuts against the cap member 150, and the stepped surface 122 of the second piston member 120 abuts against the stepped surface 152 of the cap member 150.

[0050] According to the clamping device 1 of this embodiment, the protrusions 2A provided on the main surface 2B of the workpiece 2 can be fixed from below, so that all other surfaces of the workpiece 2 (the remaining five surfaces if the workpiece is a hexahedron) can be machined.

[0051] Furthermore, since the workpiece 2 is fixed using the protrusions 2A that are integral with it, there is no need to attach other parts such as pins to the workpiece 2. The protrusions 2A can be easily formed if the workpiece 2 is a cast metal. Furthermore, the protrusions 2A can be easily formed even if the workpiece 2 is small and thin. Furthermore, protrusions 2A that are not needed in the final form after processing can be removed by grinding, and since they are not reused like other parts such as pins, there is no problem with plastically deforming them using the engaging portion 300.

[0052] The height of the protrusion 2A is, for example, about 5 mm or more and about 15 mm or less (more preferably about 10 mm or less). The diameter of the protrusion 2A (the diameter of the smallest tip portion) is about 4 mm or more (more preferably about 5 mm or more) and about 15 mm or less (more preferably about 10 mm or less). However, the height and diameter of the protrusion 2A are not limited to the above ranges.

[0053] When the workpiece 2 is made of a casting, the protrusion 2A has a tapered shape in which the diameter decreases with increasing distance from the main surface 2B of the workpiece 2. The inclination angle of the outer peripheral surface (tapered surface) of the protrusion 2A relative to the axis of the protrusion 2A is, for example, about 0.5° or more (more preferably about 1° or more) and about 3° or less, but is not limited to this. Because the protrusion 2A has a tapered shape, when the protrusion 2A is inserted into the accommodation portion 200, the engagement portion 300 can be pushed outward in the radial direction while the protrusion 2A is inserted.

[0054] Furthermore, since the working medium for engaging the engagement portion 300 with the protrusion 2A and the working medium for pulling the workpiece 2 downward after engagement can be supplied from the same circuit (flow paths 3A, 142A), the system configuration is simplified and the overall system can be made smaller.

[0055] As described above, the clamping device 1 according to this embodiment and the clamping method using the same are capable of fixing a small and thin workpiece 2, and also enable the overall system to be made smaller.

[0056] Next, a modified example of the clamp device 1 will be described with reference to Figures 5 and 6. The modified example of Figures 5 and 6 does not include the third piston member 130 and the second cylinder chamber 162, and instead uses a coil spring 500 to urge the second piston member 120 upward.

[0057] In the example of FIG. 5, a coil spring 500 is disposed in the third cylinder chamber 163 (unclamping chamber).

[0058] During a clamping operation of the clamp device 1 shown in FIG. 5, the second piston member 120 (second portion) is biased by the coil spring 500 in the opposite direction to the first piston member 110 (upward in FIG. 5), but the downward biasing force (first biasing force) from the first cylinder chamber 161 on the first piston member 110 (first portion) is greater than the upward biasing force (second biasing force) from the coil spring 500 on the second piston member 120 (second portion). Therefore, after the engaging portion 300 engages with the protrusion 2A, the second piston member 120 moves downward together with the first piston member 110 and the engaging portion 300 against the biasing force of the coil spring 500. During an unclamping operation, the second piston member 120 moves upward due to the biasing force of the third cylinder chamber 163 and the biasing force of the coil spring 500.

[0059] 6, the coil spring 500 is disposed in an internal space isolated from the third cylinder chamber 163 (unclamping chamber). Specifically, the rod portion 151 of the cap member 150 includes an inner circumferential wall portion 151A, an outer circumferential wall portion 151B, and a recess 151C provided between the inner circumferential wall portion 151A and the outer circumferential wall portion 151B, and the coil spring 500 is disposed in the recess 151C. The outer circumferential wall portion 151B fits into the inner periphery of the first piston member 110, thereby isolating the installation space of the coil spring 500 from the third cylinder chamber 163.

[0060] During the clamping operation of the clamp device 1 shown in FIG. 6, the second piston member 120 (second portion) is biased by the coil spring 500 in the opposite direction to the first piston member 110 (upward in FIG. 6), but the downward biasing force (first biasing force) from the first cylinder chamber 161 on the first piston member 110 (first portion) is greater than the upward biasing force (second biasing force) from the coil spring 500 on the second piston member 120 (second portion). Therefore, after the engaging portion 300 engages with the protrusion 2A, the second piston member 120 moves downward together with the first piston member 110 and the engaging portion 300 against the biasing force of the coil spring 500. During the unclamping operation, the second piston member 120 moves upward due to the biasing force of the coil spring 500.

[0061] In the clamping device 1 shown in FIGS. 5 and 6, similarly to the examples shown in FIGS. 1 to 4, it is possible to fix a small and thin workpiece 2, and also to achieve a reduction in the size of the entire system.

[0062] Although the embodiments of the present technology have been described above, the embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present technology is defined by the claims, and it is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0063] 1 clamping device, 2 workpiece, 2A protrusion, 2B main surface, 3 base, 3A, 3B flow path, 3C air passage, 100 main body, 110 first piston member, 111 inclined surface, 112 connecting passage, 120 second piston member, 121 holding portion, 122 stepped surface, 130 third piston member, 140 cylinder main body, 141 positioning surface, 142A, 142B flow path, 142C air passage, 150 cap member, 151 rod portion, 151A inner peripheral wall portion, 151B outer peripheral wall portion, 151C recess, 152 stepped surface, 160 cylinder chamber, 161 first cylinder chamber, 162 second cylinder chamber, 163 third cylinder chamber, 200 accommodating portion, 300 engaging portion, 400 bolt, 500 coil spring.

Claims

1. a housing portion capable of housing a protrusion protruding from a main surface of the workpiece; an engaging portion provided in the accommodation portion and engaging with the protrusion while plastically deforming an outer peripheral surface of the protrusion; a main body including a cylinder drive unit that engages the protrusion with the engagement portion and moves the engagement portion along a first direction while the protrusion and the engagement portion are engaged.

2. the main body includes a first portion that can drive the engagement portion in the first direction and a second direction perpendicular to the first direction, and a second portion that holds the engagement portion movably in the second direction; While holding the second portion in the first direction, the cylinder driving portion drives the first portion in the first direction to engage the engaging portion with the outer peripheral surface of the protrusion; 2. The clamping device according to claim 1, wherein the first portion, the engaging portion, and the second portion are moved along the first direction by driving the first portion in the first direction with the cylinder driving portion while the engaging portion is engaged with the outer peripheral surface of the protrusion.

3. When the engaging portion is engaged with the outer peripheral surface of the protrusion, the first portion is urged in the first direction by a first urging force, and the second portion is urged in the opposite direction to the first portion by a second urging force, The clamping apparatus of claim 2 , wherein the first biasing force is greater than the second biasing force.

4. the cylinder driving portion includes a first cylinder chamber that urges the first portion in the first direction, and a second cylinder chamber that communicates with the first cylinder chamber and urges the second portion in a direction opposite to that of the first portion, The clamp device according to claim 2 , wherein the biasing force exerted by the first cylinder chamber is greater than the biasing force exerted by the second cylinder chamber.

5. a positioning surface facing the main surface of the workpiece; an air passage opening to the positioning surface, 5. The clamping device according to claim 1, wherein the clamping device is configured to detect that the main surface of the workpiece has come into contact with the positioning surface based on an increase in air pressure in the air passage.

6. The clamping device according to claim 1 , wherein the engaging portion includes a plurality of steel balls.

7. 5. The clamping device according to claim 2, wherein the first portion of the main body abuts the engagement portion and includes an inclined surface that inclines toward the axis of the protrusion as it approaches the main surface of the workpiece.

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