Clamp unit and clamp system

Abstract

To provide a clamp unit which enables improvement of arrangement flexibility when multiple clamp units are combined.SOLUTION: A clamp unit of the invention includes a clamp mechanism which is turned into a clamp state when pressures in pressure action chambers defined in a case are a predetermined threshold value or lower and turned into an unclamp state when the pressures in the pressure action chambers are larger than the predetermined threshold value. A first opening and a second opening communicating with each other through supply / discharge ports, respectively going through the pressure action chambers, are respectively provided on a first outer side surface and a second outer side surface of the case of the clamp unit.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a clamp unit and a clamp system.

Background Art

[0002] In contouring devices and the like used for holding workpieces, a clamp unit capable of switching between a clamped state that allows relative movement of a shaft member to which a contact or the like is attached and an unclamped state that restricts relative movement of the shaft member is sometimes used.

[0003] As a clamp unit, for example, a combination of a first clamp mechanism capable of restricting relative movement of a shaft member in a first direction along the axial direction of the shaft member and a second clamp mechanism capable of restricting relative movement of the shaft member in a second direction opposite to the first direction along the axial direction of the shaft member is known (see, for example, Patent Document 1).

[0004] The first clamp mechanism and the second clamp mechanism each include: an outer cylinder which is a cylindrical member into which the shaft member is inserted, and has a tapered surface formed on an inner peripheral surface surrounding the outer peripheral surface of the shaft member; an inner cylinder arranged inside the outer cylinder; a plurality of rolling elements held by the inner cylinder; and a biasing member that biases the rolling elements from the large diameter side to the small diameter side of the tapered surface via the inner cylinder.

[0005] In the above-described clamp unit, the first clamp mechanism is arranged such that the direction from the large diameter side to the small diameter side of the tapered surface coincides with the first direction, and the second clamp mechanism is arranged such that the direction from the large diameter side to the small diameter side of the tapered surface coincides with the second direction. This makes it possible to restrict relative movement of the shaft member in the first direction with respect to the clamp unit and relative movement of the shaft member in the second direction with respect to the clamp unit. Furthermore, for each of the first clamp mechanism and the second clamp mechanism, by moving the rolling elements from the small diameter side to the large diameter side of the tapered surface via the inner cylinder, it becomes possible to allow relative movement of the shaft member in the first direction with respect to the clamp unit and relative movement of the shaft member in the second direction with respect to the clamp unit. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2014-66365 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] In clamp units as described above, switching from a clamped state to an unclamped state may be performed using fluid pressure such as air pressure. In such cases, it is necessary to attach fluid piping to each clamp unit. When fluid piping is attached to each clamp unit, if multiple clamp units are combined to form a tracking device, the fluid piping may interfere with other clamp units, potentially reducing the flexibility of the arrangement of the clamp units.

[0008] This invention has been made in view of the circumstances described above, and its purpose is to provide a clamp unit that can increase the degree of freedom in arrangement when combining multiple clamp units. [Means for solving the problem]

[0009] The clamping unit according to the present invention is A substantially rectangular parallelepiped member having a through hole that penetrates in the longitudinal direction, wherein a shaft member is inserted through the through hole, A clamping mechanism is provided, which is positioned in the through-hole and enters a clamped state that restricts relative movement between the case and the shaft member in the longitudinal direction when the pressure in the pressure chamber defined within the case is below a predetermined threshold, and enters an unclamped state that allows relative movement between the case and the shaft member in the longitudinal direction when the pressure of the pressure chamber is greater than the predetermined threshold. A first opening is provided on the first outer surface of the plurality of outer surfaces in the case, A second opening is provided on a second outer side of the case, which is different from the first outer side of the multiple outer sides of the case, A supply and discharge port is defined within the case, extending from the first opening through the pressure chamber to the second opening, It is equipped with.

[0010] Furthermore, the present invention can also be considered as a clamping system composed of multiple clamping units connected together. In that case, the clamping system would be, for example, A plurality of clamp units arranged such that the second opening on the second outer side surface of one of two adjacent clamp units faces the first opening on the first outer side surface of the other clamp unit, A pair of plates connected to each other while clamping multiple clamp units, Equipped with, Of the pair of plates, the plate positioned on the starting end side in the arrangement direction may be provided with a supply / discharge hole located at a position corresponding to the first opening of the clamp unit positioned at the starting end in the arrangement direction. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a clamping unit that can increase the degree of freedom in arrangement when combining multiple clamping units. [Brief explanation of the drawing]

[0012] [Figure 1] This is a first perspective view showing the appearance of the clamp unit in the embodiment. [Figure 2] This is a second perspective view showing the appearance of the clamp unit in the embodiment. [Figure 3] This figure shows an example of the configuration of the clamp unit case in the embodiment. [Figure 4] This is a perspective view of a clamp unit with a transparent case. [Figure 5]It is a cross-sectional view of the clamp unit in a clamped state as viewed from the lateral direction in the embodiment. [Figure 6] It is a cross-sectional view of the intermediate cylinder in the embodiment as viewed from the longitudinal direction. [Figure 7] It is a cross-sectional view of the clamp unit in the embodiment as viewed from the longitudinal direction. [Figure 8] It is a cross-sectional view of the vicinity of the pressure acting chamber of the clamp unit in the embodiment as viewed from the lateral direction. [Figure 9] It is a cross-sectional view of the clamp unit in an unclamped state as viewed from the lateral direction in the embodiment. [Figure 10] It is a diagram for explaining an example of a method of singly using the clamp unit in the embodiment. [Figure 11] It is a first diagram for explaining an example in which a plurality of the clamp units in the embodiment are connected to constitute a clamp system. [Figure 12] It is a second diagram for explaining an example in which a plurality of the clamp units in the embodiment are connected to constitute a clamp system. [Figure 13] It is a third diagram for explaining an example in which a plurality of the clamp units in the embodiment are connected to constitute a clamp system. [Figure 14] It is a diagram showing the flow of air in the clamp system in the embodiment. [Figure 15] It is a diagram showing an example of constituting a tracing device using the clamp unit in the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] In the clamping unit according to the present invention, when the pressure in the pressure chamber is below a predetermined threshold, the clamping mechanism restricts the relative movement between the case and the shaft member in the longitudinal direction of the case (axial direction of the shaft member) (clamped state). When the pressure in the pressure chamber is greater than the predetermined threshold, the clamping mechanism allows the relative movement between the case and the shaft member in the longitudinal direction of the case (unclamped state). The clamping mechanism may be configured to restrict the relative movement between the case and the shaft member in both directions in the longitudinal direction of the case, or it may be configured to restrict the relative movement between the case and the shaft member in one direction in the longitudinal direction of the case.

[0014] The clamp unit according to the present invention makes it possible to connect and use multiple clamp units. When a clamp system is constructed by connecting multiple clamp units according to the present invention, for example, the multiple clamp units may be arranged such that the first opening on the second outer side surface of one of two adjacent clamp units faces the second opening on the first outer side surface of the other clamp unit, and these multiple clamp units may be connected by clamping them with a pair of plates. In this case, the plate positioned on the starting end side in the arrangement direction of the pair of plates may be provided with a supply and discharge hole at a position corresponding to the first opening of the clamp unit positioned at the starting end in the arrangement direction.

[0015] As described above, when the clamping mechanisms of multiple connected clamping units are in the clamped state, if fluid (e.g., air) is supplied to the supply and discharge holes of the plate located at the starting end in the arrangement direction, the fluid flows into the supply and discharge port through the first opening of the clamping unit located at the starting end in the arrangement direction. The fluid that flows into the supply and discharge port is discharged from the second opening via the pressure chamber. The fluid that flows out from the second opening of the clamping unit located at the starting end in the arrangement direction flows into the supply and discharge port through the first opening of the clamping unit adjacent to that clamping unit. As a result of this fluid flow, the pressure in the pressure chambers of the multiple clamping units becomes greater than a predetermined threshold. Consequently, the clamping mechanisms of the multiple clamping units switch from the clamped state to the unclamped state almost simultaneously.

[0016] As described above, when multiple connected clamp units are in the unclamped state, if the fluid supply to the supply and discharge holes of the plate located on the starting end side in the arrangement direction is stopped, the fluid in the pressure chamber of the clamp unit located on the starting end side in the arrangement direction is discharged through the supply and discharge port to the first opening. The fluid discharged from the first opening of the clamp unit located on the starting end side in the arrangement direction is then discharged to the supply and discharge holes of the plate located on the starting end side in the arrangement direction. Consequently, in the clamp units other than the clamp unit located on the starting end side in the arrangement direction, the fluid in the pressure chamber flows through the supply and discharge port to the first opening, and is discharged from the first opening to the second opening of the adjacent clamp unit. As a result of this fluid flow, the pressure in the pressure chambers of the multiple clamp units falls below a predetermined threshold. Consequently, the clamping mechanisms of the multiple clamp units switch from the unclamped state to the clamped state almost simultaneously.

[0017] Furthermore, when multiple clamp units are connected and used, fluid supply and discharge may be performed not only from the first opening of the clamp unit located at the beginning of the arrangement direction, but also from the second opening of the clamp unit located at the end of the arrangement direction. In that case, the plate located at the end of the arrangement direction is the second opening of the clamp unit located at the end of the arrangement direction. The device should be equipped with supply and discharge holes located at positions corresponding to the two openings. This makes it possible to reduce the time lag between multiple clamp units involved in switching between the clamped and unclamped states, for example, when there are many clamp units connected.

[0018] According to the present invention, it becomes possible to configure a clamp system by connecting multiple clamp units. Furthermore, according to the present invention, when configuring a clamp system by connecting multiple clamp units, it becomes unnecessary to attach fluid piping to each clamp unit. This increases the degree of freedom in arranging the clamp units when configuring a tracking device or the like by combining multiple clamp units. Moreover, since it becomes unnecessary to connect fluid piping to each of the multiple clamp units, it becomes possible to reduce the number of parts when using multiple clamp units in combination, and consequently, it becomes possible to simplify the work of rearranging the clamp units.

[0019] <Embodiment> The following describes specific embodiments of the present invention with reference to the drawings. Unless otherwise specified, the dimensions, materials, shapes, relative arrangements, etc., of the components described in these embodiments are not intended to limit the technical scope of the invention to those specific components.

[0020] (Outline configuration of the clamp unit) The schematic configuration of the clamp unit 1 in this embodiment will be described based on Figures 1 to 3. Figure 1 is a first perspective view of the clamp unit 1 in this embodiment. Figure 2 is a second perspective view of the clamp unit 1 from the direction of arrow A in Figure 1. Figure 3 is a diagram showing the shape of the through hole 20 in the case 2. Figure 4 is a perspective view with a portion of the case 2 in Figure 1 transparent.

[0021] The clamp unit 1 of this embodiment includes a case 2, as shown in Figures 1 to 3. In the example shown in Figures 1 to 3, the case 2 has a rectangular parallelepiped shape, but it may also have a substantially rectangular parallelepiped shape with its longitudinal end faces curved in a convex or concave shape, or it may have a substantially rectangular parallelepiped shape with the outer sides other than the first outer side 22 and the second outer side 23, which will be described later, curved in a convex or concave shape among a plurality of outer sides extending in the longitudinal direction. As shown in Figure 3, a cylindrical through hole 20 is formed in the case 2, penetrating from one end face to the other in the longitudinal direction. As shown in Figure 4, a clamp mechanism 200 is housed in the through hole 20 of the case 2. A shaft member 100 is inserted through the clamp mechanism 200. The clamp mechanism 200 has a function to switch between a clamp state, which restricts the relative movement of the shaft member 100 with respect to the clamp unit 1, and an unclamped state, which allows the relative movement of the shaft member 100 with respect to the clamp unit 1. In this embodiment, the switching between the clamped state and the unclamped state by the clamping mechanism 200 is performed by air pressure supplied and discharged by an externally installed air pump or the like. Details of the clamping mechanism 200 will be described later.

[0022] Guide devices 3 are attached to each end of the case 2 in the longitudinal direction. The guide devices 3 guide the shaft member 100, which is inserted into the case 2, linearly along the longitudinal direction. The guide devices 3 are, for example, linear bearings equipped with multiple rolling elements. The guide devices 3 may be attached to the case 2 by, for example, providing the guide device 3 with a flange 30 that is substantially the same shape as the end face of the case 2 in the longitudinal direction, and fixing the flange 30 to the case 2 with bolts or the like. In this case, a dovetail joint structure may be adopted in which a part of the guide device 3 fits into a through hole 20 of the case 2. This allows for accurate positioning of the shaft member 100.

[0023] One of the four outer sides of Case 2, the first outer side 22 (the outer side facing forward in Figures 1 and 3), has a cylindrical shape extending along the shorter side of Case 2. A recess 6 is formed. In the examples shown in Figures 1 and 3, the recess 6 is provided in the center of the first outer surface 22, but it may also be provided at an offset position from the center of the first outer surface 22.

[0024] The recess 6 of the first outer surface 22 is provided with a pair of first openings 7 and a pair of screw holes 8 for supplying and exhausting air into and out of the case 2. The pair of first openings 7 are arranged along the short direction of the first outer surface 22. The pair of screw holes 8 are arranged between the pair of first openings 7 along the short direction of the first outer surface 22. The pair of screw holes 8 are formed to penetrate to the through hole 20 of the case 2.

[0025] Of the four outer sides of case 2, the second outer side 23 (the outer side facing forward in Figure 2), which is located opposite the first outer side 22, is provided with a pair of second openings 9 and a pair of screw holes 8 for supplying and exhausting air into case 2. The pair of second openings 9 are arranged along the short direction of the second outer side 23. The position of the pair of second openings 9 in the longitudinal direction and the position of the short direction of case 2 are the same as that of the pair of first openings 7. The pair of screw holes 8 are arranged between the pair of second openings 9 along the short direction of the second outer side 23. The pair of screw holes 8 provided on the second outer side 23 are formed to penetrate to the through hole 20 of case 2, similar to the pair of screw holes 8 provided on the first outer side 22.

[0026] A third opening 4 for supplying and discharging air into the case 2 is provided on the third outer side surface 21 (the outer side surface facing upward in Figures 1-2 and 4), which is adjacent to the first outer side surface 22 and the second outer side surface 23 of the four outer side surfaces of case 2. In the example shown in Figures 1-2 and 4, the third opening 4 is located in the center of the third outer side surface 21 (where the center of the third opening 4 coincides with the point where two diagonals on the third outer side surface 21 intersect), but it may also be located at an offset position from the center of the third outer side surface 21.

[0027] Case 2 is provided with a plurality of through holes 5 that penetrate along the shorter side of Case 2, from the first outer side surface 22 to the second outer side surface 23. The positions of the through holes 5 are not particularly limited as long as they can avoid the through holes 20, but they may be provided near each of the four corners on the first outer side surface 22 and the second outer side surface 23.

[0028] (Configuration of the clamping mechanism) Here, the specific configuration of the clamping mechanism 200 will be explained based on Figures 5 to 9. Figure 5 is a cross-sectional view of the clamping unit 1 in the clamped state, viewed from the short side. Figure 6 is a cross-sectional view of the intermediate cylinder 230, viewed from the long side. Figure 7 is a cross-sectional view of the clamping unit 1, viewed from the long side. Figure 8 is a cross-sectional view of the vicinity of the pressure chamber 240, viewed from the short side. Figure 9 is a cross-sectional view of the clamping unit 1 in the unclamped state, viewed from the short side.

[0029] The clamping mechanism 200 in this embodiment comprises a first clamping mechanism 210, a second clamping mechanism 220, an intermediate cylinder 230, and a pressure chamber 240. The first clamping mechanism 210 is a mechanism for restricting the movement of the shaft member 100 in a first direction in the longitudinal direction (from left to right in Figure 5). The second clamping mechanism 220 is a mechanism for restricting the movement of the shaft member 100 in a second direction opposite to the first direction in the longitudinal direction (from right to left in Figure 5). The intermediate cylinder 230 is a member positioned between the first clamping mechanism 210 and the second clamping mechanism 220.

[0030] As shown in Figure 5, the first clamping mechanism 210 comprises a first outer cylinder 211 and a first inner cylinder 2 It comprises 12, a plurality of first rolling elements 213, a first coil spring 214, a first piston 215, and a first packing 216.

[0031] The first outer cylinder 211 is a cylindrical member having an outer diameter equal to or slightly smaller than the inner diameter of the through hole 20, and an inner diameter larger than the outer diameter of the shaft member 100. A tapered surface is formed on the inner circumferential surface of the first outer cylinder 211 on the side facing the first direction, with the inner diameter continuously decreasing toward the first direction. As a result, a wedge-shaped space is formed between the tapered surface of the first outer cylinder 211 and the outer circumferential surface of the shaft member 100.

[0032] The first inner cylinder 212 is a cylindrical member positioned between the guide device 3, located on the first direction side in the longitudinal direction, and the first outer cylinder 211. The first inner cylinder 212 has an inner diameter equal to or slightly larger than the outer diameter of the shaft member 100. The first inner cylinder 212 is formed to have an outer diameter smaller than the smallest diameter portion of the tapered surface on the inner circumferential surface of the first outer cylinder 211, and a portion of it is inserted between the first outer cylinder 211 and the shaft member 100. The end of the first inner cylinder 212 on the first direction side is enlarged to have an outer diameter equal to or slightly smaller than the inner diameter of the through hole 20.

[0033] In the portion of the first inner cylinder 212 that is inserted between the first outer cylinder 211 and the shaft member 100, a plurality of first rolling elements 213 are held that roll along the longitudinal direction in the gap between the tapered surface of the first outer cylinder 211 and the outer circumferential surface of the shaft member 100. The plurality of first rolling elements 213 are arranged in a ring along the circumferential direction of the first inner cylinder 212 and are rotatably held in the first inner cylinder 212. The first rolling elements 213 are, for example, guide rollers. The first rolling elements 213 may also be balls.

[0034] The first coil spring 214 is housed within the first outer cylinder 211 and biases the first outer cylinder 211 in a second direction relative to the first inner cylinder 212. The first coil spring 214 is an example of the "first biasing member" according to the present invention. Note that the component that biases the first outer cylinder 211 in the second direction is not limited to a coil spring, but can be anything with elasticity.

[0035] The first piston 215 is a cylindrical member positioned adjacent to the second direction side of the first outer cylinder 211. The first piston 215 has an inner diameter equal to or slightly larger than the outer diameter of the shaft member 100. The first piston 215 has an outer diameter smaller than the inner diameter of the through hole 20. However, the end of the first piston 215 on the first direction side is enlarged to have an outer diameter equal to or slightly smaller than the inner diameter of the through hole 20.

[0036] The first packing 216 is an annular member having an outer diameter equal to or slightly larger than the inner diameter of the through hole 20, and an inner diameter equal to or slightly smaller than the outer diameter of the first piston 215. The first packing 216 is fitted to the outer circumferential surface of the first piston 215. At that time, the first packing 216 is fitted so that its end on the first direction side abuts against the enlarged diameter portion of the first piston 215.

[0037] Next, as shown in Figure 5, the second clamping mechanism 220 is composed of a second outer cylinder 221, a second inner cylinder 222, a plurality of second rolling elements 223, a second coil spring 224 (corresponding to the "second biasing member" according to the present invention), a second piston 225, and a second packing 226. The second outer cylinder 221, the second inner cylinder 222, the second rolling elements 223, the second coil spring 224, the second piston 225, and the second packing 226 are configured in the same way as the first outer cylinder 211, the first inner cylinder 212, the first rolling elements 213, the first coil spring 214, the first piston 215, and the first packing 216 of the first clamping mechanism 210. However, the second outer cylinder 221, the second inner cylinder 222, the second rolling element 223, the second coil spring 224, the second piston 225, and the second packing 226 are connected to the first clamping mechanism 21 They are arranged in the opposite direction to 0. That is, the second clamping mechanism 220 is positioned such that the tapered surface of the second outer cylinder 221 becomes continuously smaller toward the second direction.

[0038] The intermediate cylinder 230 is a substantially cylindrical member positioned in the center of the through hole 20 in the longitudinal direction, between the first clamping mechanism 210 and the second clamping mechanism 220. The intermediate cylinder 230 has an outer diameter equal to or slightly smaller than the inner diameter of the through hole 20. The intermediate cylinder 230 has an inner diameter larger than the outer diameter of the shaft member 100. Parts of the first piston 215 and the second piston 225 are inserted between the inner circumferential surface of the intermediate cylinder 230 and the outer circumferential surface of the shaft member 100 so as to be able to move back and forth along the longitudinal direction. At this time, the inner diameter of the intermediate cylinder 230, the thickness of the first piston 215 (distance from the inner circumferential surface to the outer circumferential surface in the radial direction), and the thickness of the second piston 225 (distance from the inner circumferential surface to the outer circumferential surface in the radial direction) are determined such that the distance between the inner circumferential surface of the intermediate cylinder 230 and the outer circumferential surface of the shaft member 100 is equal to or slightly larger than the thickness of the first piston 215 and the second piston 225.

[0039] In this embodiment, as shown in Figure 6, a pair of flat surfaces 231 are provided at two locations on the outer circumferential surface of the intermediate cylinder 230. The pair of flat surfaces 231 are formed on opposite sides of the central axis of the intermediate cylinder 230. At that time, the pair of flat surfaces 231 are formed so that they are parallel to each other. The intermediate cylinder 230 configured in this way is fixed to the case 2, as shown in Figure 7, with the pair of flat surfaces 231 parallel to the third outer surface 21 of the case 2. The intermediate cylinder 230 is fixed by set screws 80 that are screwed into the two screw holes 8 of the first outer surface 22 and the two screw holes 8 of the second outer surface 23. In the example shown in Figure 7, the intermediate cylinder 230 is fixed by four set screws 80, but the number of set screws may be three or fewer, or five or more.

[0040] As described above, when the intermediate cylinder 230 is fixed to the case 2, a pair of pressure chambers 240 are formed, as shown in Figures 7 and 8, by the inner circumferential surface of the through hole 20, the flat portion 231 of the intermediate cylinder 230, the outer circumferential surface of the first piston 215, the outer circumferential surface of the second piston 225, the end face of the first packing 216 on the second direction side, and the end face of the second packing 226 on the first direction side. Hereinafter, of the pair of pressure chambers 240, the pressure chamber 240 closer to the third outer side surface 21 will be referred to as the "first pressure chamber 240A," and the other pressure chamber 240 will be referred to as the "second pressure chamber 240B." When describing the first pressure chamber 240A and the second pressure chamber 240B in common, they will be referred to as pressure chamber 240.

[0041] Case 2 is provided with a pair of first supply and discharge ports 70 for connecting a pair of first openings 7 and a pair of second openings 9, respectively, as shown in Figures 7 and 8. Of the pair of first supply and discharge ports 70, one first supply and discharge port 70 (the upper first supply and discharge port 70A in Figure 7) is formed to pass through the first pressure chamber 240A. Of the pair of first supply and discharge ports 70, the other first first supply and discharge port 70 (the lower first supply and discharge port 70B in Figure 7) is formed to pass through the second pressure chamber 240B. Case 2 is also provided with a second supply and discharge port 40 for connecting a third opening 4 on the third outer side surface 21 to the first pressure chamber 240A.

[0042] In the clamping mechanism 200 configured as described above, when the pressure in the pressure chamber 240 is less than or equal to the biasing force of the first coil spring 214 and the second coil spring 224, the first clamping mechanism 210 and the second clamping mechanism 220 are in a clamped state, as shown in Figure 5. That is, in the first clamping mechanism 210, the biasing force of the first coil spring 214 biases the first outer cylinder 211 in the second direction, and consequently the first rolling element 213 is pressed from the larger diameter side to the smaller diameter side of the tapered surface of the first outer cylinder 211. As a result, when an external force is applied that moves the shaft member 100 in the first direction, the first rolling element 213 bites into the wedge-shaped space defined by the tapered surface and the outer circumferential surface of the shaft member 100, thereby clamping the clamping unit 1. The relative movement of the shaft member 100 in the first direction is restricted. In the second clamping mechanism 220, the biasing force of the second coil spring 224 biases the second outer cylinder 221 in the first direction, and consequently the second rolling element 223 is pressed from the larger diameter side to the smaller diameter side of the tapered surface of the second outer cylinder 221. As a result, when an external force is applied that moves the shaft member 100 in the second direction, the second rolling element 223 bites into the wedge-shaped space defined by the tapered surface and the outer circumferential surface of the shaft member 100, thereby restricting the relative movement of the shaft member 100 with respect to the clamping unit 1 in the second direction. Therefore, when the pressure in the pressure chamber 240 is less than or equal to the biasing force of the first coil spring 214 and the second coil spring 224, the relative movement of the shaft member 100 with respect to the clamping unit 1 is restricted in both the first and second directions.

[0043] Furthermore, in the clamp mechanism 200 configured as described above, when the pressure in the pressure chamber 240 becomes greater than the biasing force of the first coil spring 214 and the second coil spring 224, the first clamp mechanism 210 and the second clamp mechanism 220 switch from a clamped state to an unclamped state, as shown in Figure 9. Specifically, in the first clamp mechanism 210, the first piston 215 is displaced in the first direction by the pressure in the pressure chamber 240. As a result, the first piston 215 presses the first outer cylinder 211 in the first direction, and consequently, the first rolling element 213 rolls from the smaller diameter side to the larger diameter side of the tapered surface of the first outer cylinder 211. Consequently, the first rolling element 213 rolls out of the wedge-shaped space. Therefore, relative movement of the shaft member 100 with respect to the clamp unit 1 in the first direction is permitted. Furthermore, in the second clamping mechanism 220, the second piston 225 is displaced in a second direction by the pressure of the pressure chamber 240. As a result, the second piston 225 presses the second outer cylinder 221 in the second direction, and consequently, the second rolling element 223 rolls from the smaller diameter side to the larger diameter side of the tapered surface of the second outer cylinder 221. Consequently, the second rolling element 223 rolls out of the wedge-shaped space. Therefore, relative movement of the shaft member 100 with respect to the clamping unit 1 in the second direction is permitted. Thus, when the pressure in the pressure chamber 240 is greater than the biasing force of the first coil spring 214 and the second coil spring 224, relative movement of the shaft member 100 with respect to the clamping unit 1 is permitted in both the first and second directions.

[0044] Furthermore, the clamping mechanism 200 is not limited to having both the first pressure chamber 240A and the second pressure chamber 240B, but may also have only the first pressure chamber 240A.

[0045] (Effects of this embodiment) Here, the effects and advantages of this embodiment will be explained based on Figures 10 to 15. Figure 10 is a diagram illustrating how to use a clamp unit 1 individually. Figure 11 is a first diagram illustrating an example of how to use multiple clamp units 1 in a connected manner. Figure 12 is a second diagram illustrating an example of how to use multiple clamp units 1 in a connected manner. Figure 13 is a third diagram illustrating an example of how to use multiple clamp units 1 in a connected manner. Figure 14 is a diagram illustrating the airflow when multiple clamp units 1 are used in a connected manner. Figure 15 is a diagram illustrating an example of how to configure a tracing device using multiple clamp units 1.

[0046] First, when using the clamp unit 1 alone, as shown in Figure 10, the first opening 7 on the first outer side surface 22 is sealed with a sealing member 71, and the second opening 9 on the second outer side surface 23 is sealed with a sealing member 91. Set screws can be used as the sealing members 71 and 91. In that case, screw grooves should be formed in the first opening 7 and the second opening 9. Also, one end of the air piping is connected to the third opening 4 on the third outer side surface 21. The other end of the air piping is connected to, for example, an air pump installed externally.

[0047] In the state shown in Figure 10, when air is supplied from the air pump to the third opening 4, the supplied air flows from the third opening 4 through the second supply / discharge port 40 into the first pressure chamber 240A. As a result, the pressure in the first pressure chamber 240A rises to a pressure greater than the biasing force of the first coil spring 214 and the second coil spring 224. When the pressure in the first pressure chamber 240A becomes greater than the biasing force of the first coil spring 214 and the second coil spring 224, the first piston 215 is displaced in the first direction and the second piston 225 is displaced in the second direction, causing the first clamping mechanism 210 and the second clamping mechanism 220 to become unclamped, as shown in Figure 9 above.

[0048] When the first clamping mechanism 210 and the second clamping mechanism 220 are in an unclamped state, if the air supply from the air pump to the third opening 4 is stopped, the air in the first pressure chamber 240A is discharged through the second supply / discharge port 40 to the third opening 4. As a result, the pressure in the first pressure chamber 240A drops to below the biasing force of the first coil spring 214 and the second coil spring 224. When the pressure in the first pressure chamber 240A falls below the biasing force of the first coil spring 214 and the second coil spring 224, the biasing force of the first coil spring 214 displaces the first outer cylinder 211 and the first piston 215 in the second direction, and the biasing force of the second coil spring 224 displaces the second outer cylinder 221 and the second piston 225 in the first direction. As a result, the first rolling element 213 rolls into the wedge-shaped space between the tapered surface of the first outer cylinder 211 and the outer circumferential surface of the shaft member 100, and the second rolling element 223 rolls into the wedge-shaped space between the tapered surface of the second outer cylinder 221 and the outer circumferential surface of the shaft member 100. Consequently, as shown in Figure 5 above, the first clamping mechanism 210 and the second clamping mechanism 220 are clamped.

[0049] Next, an example of configuring a clamp system by connecting multiple clamp units 1 will be explained based on Figures 11 to 14. Here, an example of configuring a clamp system by connecting three clamp units 1 will be explained. The three clamp units 1 will be referred to as the first clamp unit 1A, the second clamp unit 1B, and the third clamp unit 1C, in the order in which they are connected.

[0050] When connecting the first to third clamp units 1A-1C, as shown in Figure 11, the first to third clamp units 1A-1C are sandwiched between a pair of plates 510-520 and fastened with fastening bolts 270. For this connection, a packing 60 is fitted into each of the recesses 6A-6C of the first to third clamp units 1A-1C, having an outer diameter approximately equal to the inner diameter of the recess 6A-6C and a thickness slightly greater than the depth of the recess 6A-6C. Furthermore, a sealing member 41 is attached to each of the third openings 4 of the first to third clamp units 1A-1C, as shown in Figure 13. A set screw can be used as the sealing member 41. In that case, a screw groove should be formed in each of the third openings 4 of the first to third clamp units 1A-1C.

[0051] After attaching the packing 60 and sealing member 41 to each of the first to third clamp units 1A-1C, the first to third clamp units 1A-1C are arranged such that the second outer side surface 23A of the first clamp unit 1A and the first outer side surface 22B of the second clamp unit 1B are in contact with each other, and the second outer side surface 23B of the second clamp unit 1B and the first outer side surface 22C of the third clamp unit 1C are in contact with each other. A plate 510 is placed in contact with the first outer side surface 22A of the first clamp unit 1A. The plate 510 has one supply / discharge hole 511 and four through holes 512. The supply / discharge hole 511 is a hole that penetrates the plate 510 and is provided at a position corresponding to the recess 6 of the first clamp unit 1A. The supply / discharge hole 511 is configured to allow connection of air piping from an external air pump. The four through holes 512 of the plate 510 are located in positions corresponding to the four through holes 5 of the first clamp unit 1A. Also, the second of the third clamp unit 1C A plate 520 is placed in contact with the outer side surface 23C. A cylindrical recess 521 is provided on one surface of the plate 520 (the surface that contacts the second outer side surface 23C of the third clamp unit 1C). The recess 521 is located at a position corresponding to a pair of second openings 9 on the second outer side surface 23 of the third clamp unit 1C. A packing 61 is fitted into the recess 521, having an outer diameter approximately equal to the inner diameter of the recess 521 and a thickness slightly greater than the depth of the recess 521. The plate 520 is also provided with four through holes 522. The four through holes 522 are located at a position corresponding to the four through holes 5 of the third clamp unit 1C.

[0052] As described above, with the first to third clamp units 1A-1C and plates 510-520 arranged side by side, fastening bolts 270 are installed by sequentially passing them through the through holes 5 of the first to third clamp units 1A-1C from the through hole 512 of plate 510 to the through hole 5 of plate 520. Then, nuts are attached to the ends of the fastening bolts 270 and tightened. The tightening torque at this time may be determined, for example, so that the packings 60-61 can perform airtight sealing.

[0053] With the first to third clamp units 1A-1C connected, when air is supplied from the supply / discharge hole 511 of the plate 510, the supplied air flows from the supply / discharge hole 511 into the recess 6A of the first clamp unit 1A, as shown in Figure 14. The supplied air that flows into the recess 6A does not leak to the outside due to the action of the packing 60, and flows from the first opening 7 of the first clamp unit 1A into the first supply / discharge port 70. A portion of the supplied air that flows into the first supply / discharge port 70 flows into the pressure chamber 240, and the remaining supplied air is discharged from the second opening 9.

[0054] The supply air discharged from the second opening 9 of the first clamp unit 1A flows into the recess 6B of the second clamp unit 1B. The supply air that flows into the recess 6B does not leak to the outside due to the action of the packing 60 and flows into the first supply / discharge port 70 from the first opening 7 of the second clamp unit 1B. A portion of the supply air that flows into the first supply / discharge port 70 flows into the pressure chamber 240, and the remaining supply air is discharged from the second opening 9.

[0055] The supply air discharged from the second opening 9 of the second clamp unit 1B flows into the recess 6C of the third clamp unit 1C. The supply air that flows into the recess 6C does not leak to the outside due to the action of the packing 60 and flows into the first supply / discharge port 70 from the first opening 7 of the third clamp unit 1C. The supply air that flows into the first supply / discharge port 70 flows into the pressure chamber 240. At this time, a portion of the supply air that flows into the first supply / discharge port 70 flows into the recess 521 of the plate 520 from the second opening 9, but because the recess 521 is airtight due to the action of the packing 61, leakage of the supply air that flows into the recess 521 to the outside is suppressed.

[0056] When the supply air flow shown in Figure 14 is formed, the pressure in each of the pressure chambers 240 of the first to third clamp units 1A-1C can be made greater than the biasing force of the first coil spring 214 and the second coil spring 224. As a result, the first clamping mechanism 210 and the second clamping mechanism 220 of each of the first to third clamp units 1A-1C can be switched from the clamped state to the unclamped state, as shown in Figure 9 above.

[0057] Furthermore, when the first clamping mechanism 210 and the second clamping mechanism 220 of each of the first to third clamping units 1A-1C are in an unclamped state, and the air supply from the air pump to the supply / discharge port 511 is stopped, a flow is formed in the opposite direction to the flow shown in Figure 14, thereby creating a flow within the pressure chamber 240 of each of the first to third clamping units 1A-1C. The pressure decreases to below the biasing force of the first coil spring 214 and the second coil spring 224. As a result, the first clamping mechanism 210 and the second clamping mechanism 220 of the first to third clamping units 1C switch to the clamped state shown in Figure 5 above.

[0058] Figures 11 to 14 illustrate a method for connecting three clamp units 1, but the same method can be used to connect two or four or more clamp units 1. Furthermore, if the number of clamp units 1 to be connected increases, air supply and exhaust holes may be provided in the recess 521 of the plate 520, so that air is supplied from both the air supply and exhaust holes 5111 of the plate 510 and the air supply and exhaust holes of the plate 520.

[0059] The clamp unit 1 of the embodiment described above can be used both individually and in multiple connected units. Furthermore, when multiple units are used in a connected configuration, there is no need to connect air piping to each individual clamp unit 1, thus reducing interference with surrounding components. As a result, the degree of freedom in placement when multiple units are used in a connected configuration can be increased. For example, as shown in Figure 15, it is possible to configure a tracing device by combining a single clamp unit 1 with multiple connected clamp units 1. In this case, if the positioning of each clamp unit 1 is performed using a pair of plates 610-620 having multiple holes into which both ends in the longitudinal direction of the clamp unit 1 fit, the arrangement of the clamp units 1 can be rearranged by removing one of the plates 610. Moreover, with the clamp unit 1 of this embodiment, the clamp units 1 can be directly connected to each other, thus narrowing the spacing between the shaft members 100 in the tracing device. As a result, it becomes possible to configure a tracing device that can handle workpieces with complex shapes.

[0060] <Other examples> In the embodiments described above, a clamp unit comprising both a first clamping mechanism and a second clamping mechanism was illustrated, but it is also possible to provide only one of the first or second clamping mechanism.

[0061] Furthermore, in the embodiment described above, an example was given in which the second outer surface and the third outer surface are outer surfaces located on opposite sides of each other. However, the second outer surface and the third outer surface may be two adjacent outer surfaces out of the three outer surfaces excluding the first outer surface. In that case, the second supply and discharge port should be formed to bend appropriately at a suitable location within the case. [Explanation of Symbols]

[0062] 1...Clamping unit, 2...Case, 3...Guiding device, 4...Third opening, 6...Recess, 7...First opening, 9...Second opening, 20...Through hole, 21...Third outer side, 22...First outer side, 23...Second outer side, 41...Sealing member, 60...Packing, 70...First supply / discharge port, 71...Sealing member, 100...Shaft member, 200...Clamping mechanism, 210...First clamping mechanism, 211...First outer cylinder, 212...First inner cylinder, 213...First rolling element, 214...First coil spring, 215...First piston, 220...Second clamping mechanism, 221...First outer cylinder, 222...Second inner cylinder, 223...Second rolling element, 224...Second coil spring, 225...Second piston, 240 (240A-240B)...Pressure chamber

Claims

1. A substantially rectangular parallelepiped member having a through hole that penetrates in the longitudinal direction, wherein a shaft member is inserted through the through hole, A clamping mechanism is provided, which is positioned in the through-hole and enters a clamped state that restricts relative movement between the case and the shaft member in the longitudinal direction when the pressure in the pressure chamber defined within the case is below a predetermined threshold, and enters an unclamped state that allows relative movement between the case and the shaft member in the longitudinal direction when the pressure in the pressure chamber is greater than the predetermined threshold. A first opening is provided on the first outer surface of the plurality of outer surfaces in the case, A second opening is provided on a second outer surface of the case, which is different from the first outer surface among the multiple outer surfaces of the case, A supply and discharge port is defined within the case and communicates from the first opening through the pressure chamber to the second opening, A clamping unit equipped with the following features.

2. A columnar recess extending in the short direction of the case is formed on the first outer surface of the case. The first opening is formed in the recess, The clamping unit according to claim 1.

3. The first outer surface and the second outer surface are outer surfaces located on opposite sides of each other among the multiple outer surfaces in the case. The clamping unit according to claim 2.

4. The clamping mechanism is A cylindrical member through which the shaft member is inserted, comprising a first outer cylinder having a tapered surface formed on its inner surface surrounding the outer surface of the shaft member, the tapered surface becoming smaller in diameter toward the first direction in the longitudinal direction, A cylindrical member through which the shaft member is inserted, comprising a first inner cylinder through which a portion of the member is inserted into the gap between the tapered surface and the outer circumferential surface of the shaft member, A plurality of first rolling elements are held in the first inner cylinder and roll along the axial direction in the gap between the tapered surface and the outer circumferential surface of the shaft member, A first biasing member biases the first outer cylinder in a second direction opposite to the first direction relative to the first inner cylinder, A cylindrical member through which the shaft member is inserted, wherein one end in the longitudinal direction is positioned to abut against the end of the first outer cylinder on the second direction side, and a first piston presses the first outer cylinder in the first direction when the pressure in the pressure chamber is greater than the biasing force of the first biasing member, A first clamping mechanism comprising, The clamping unit according to claim 3.

5. The clamping mechanism is A cylindrical member through which the shaft member is inserted, the second outer cylinder having a tapered surface formed on its inner circumferential surface surrounding the outer circumferential surface of the shaft member, the tapered surface becoming smaller in diameter in the second direction, A cylindrical member through which the shaft member is inserted, wherein a part of the member is inserted into the gap between the tapered surface of the second outer cylinder and the outer circumferential surface of the shaft member, A plurality of second rolling elements are held in the second inner cylinder and roll along the axial direction in the gap between the tapered surface of the second outer cylinder and the outer circumferential surface of the shaft member, A second biasing member is provided with respect to the second inner cylinder, which biases the second outer cylinder in the first direction, A cylindrical member through which the shaft member is inserted, wherein one end in the longitudinal direction is positioned to abut against the end of the second outer cylinder on the first direction side, and a second piston presses the second outer cylinder in the second direction when the pressure in the pressure chamber is greater than the biasing force of the second biasing member, Further including a second clamping mechanism comprising: The clamping unit according to claim 4.

6. The first clamping mechanism and the second clamping mechanism are housed in the case such that the first piston and the second piston are adjacent to each other. The clamping mechanism further comprises an intermediate cylinder fixed to the case, which is a cylindrical member through which the shaft member is inserted, and in which a portion of the first piston and the second piston are inserted into the gap between the inner circumferential surface of the intermediate cylinder and the shaft member. The pressure chamber is defined by the outer circumferential surface of the intermediate cylinder, the inner circumferential surface of the case, the outer circumferential surface of the first piston, and the outer circumferential surface of the second piston. The clamping unit according to claim 5.

7. A clamping system comprising a plurality of clamping units according to any one of claims 1 to 6, A plurality of clamp units arranged such that the second opening on the second outer side surface of one of two adjacent clamp units faces the first opening on the first outer side surface of the other clamp unit, A pair of plates connected to each other while clamping multiple clamp units, Equipped with, Of the pair of plates, the plate positioned on the starting end side in the arrangement direction is provided with a supply / discharge hole located at a position corresponding to the first opening of the clamp unit positioned at the starting end in the arrangement direction. Clamping system.

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