Clamping Device

Abstract

To provide a clamp device that can prevent sputter from depositing in a relief passage formed in the clamp device.SOLUTION: A clamp device 10 is provided with: a locator pin 12 having a pin part 20 and a work-piece receiving surface 26, in which a first opening 21 is formed in a peripheral wall of the pin part; a cylindrical housing 13, connected to a base end part of the locator pin, which has second openings 32A and 32B formed at a peripheral wall thereof and has relief passages 36A and 36B; clamp arms 14, arranged in the locator pin and internal spaces 12a and 13a of the housing, which can be displaced to a clamp position and an unclamp position; and guard members 15A and 15B in a band plate-shape arranged in the relief passages. Bottom surfaces 37A and 37B of the relief passages are formed on downward inclined surfaces on which the second openings are formed at a downward side, and the guard members are formed in a downward inclined surface shape extending from side surfaces of the clamp arms to the bottom surfaces of the relief passages.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a clamping device, and more particularly to a clamping device that positions and then clamps a panel-shaped workpiece. [Background technology]

[0002] An automobile body is assembled by welding multiple panels together. When welding each panel, the panel is positioned and fixed using a clamping device. The clamping device has a positioning locating pin that is inserted into a clamping hole formed in the workpiece (panel) to be clamped, and a clamping arm that clamps the positioned workpiece.

[0003] For example, in the clamping device described in Patent Document 1, a locating pin has a pin portion that is inserted into a clamping hole in a workpiece and a workpiece receiving surface that receives the peripheral edge of the clamping hole in a panel. This locating pin has an internal space that communicates with an opening formed in the peripheral wall of the pin portion, and is attached to the tip of a cylindrical housing. The internal space of the locating pin and the internal space of the housing are connected, and the clamp arm is housed in this internal space. The clamp arm receives power from a drive mechanism and moves between a clamping position where the tip of the clamp arm protrudes outward from the opening in the locating pin to clamp a workpiece placed on the workpiece receiving surface, and an unclamping position where the tip of the clamp arm is housed within the internal space of the locating pin.

[0004] When welding is performed on a workpiece while the workpiece is clamped by a clamping device, spatter generated by the welding can enter the inside of the clamping device through the opening in the locating pin, causing malfunction of the clamp arm.

[0005] To prevent malfunctions, the clamping device described in Patent Document 1 has a relief passage in the housing for discharging spatter to the outside. The relief passage is a horizontal passage that connects the interior space of the housing with a relief opening formed in the peripheral wall of the housing. This clamping device also has a strip-shaped guard member that extends from the side of the clamp arm to the horizontal bottom surface of the relief passage.

[0006] In the clamping device described in Patent Document 1, spatter that has entered the interior of the clamping device through the opening in the locating pin passes through a passage between the inner peripheral surface of the locating pin and the surface of the guard member and is guided to an escape passage in the housing, thereby preventing spatter from entering the interior space of the housing. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-324318 Summary of the Invention [Problem to be solved by the invention]

[0008] In conventional clamping devices, the bottom of the escape passage formed in the housing is horizontal, so spatter accumulates on this bottom. If the escape passage becomes clogged with accumulated spatter, compressed air can be introduced into the escape passage to remove the spatter, but this causes dust to fly around, which is an undesirable working environment.

[0009] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a clamping device that can prevent spatter from accumulating in a spatter escape passage provided in the clamping device. [Means for solving the problem]

[0010] In order to achieve the above object, one embodiment of the present invention provides a locating pin having a pin portion to be inserted into a clamp hole formed in a panel-shaped workpiece, and a workpiece receiving surface that extends radially outward from a base end of the pin portion, with a first opening formed in a peripheral wall of the pin portion that communicates with an internal space; a cylindrical housing connected to the base end of the locating pin, having a second opening in its peripheral wall and having an escape passage that communicates the second opening with the internal space of the locating pin; and a clamping mechanism for clamping the workpiece placed on the workpiece receiving surface, the clamping mechanism being disposed in the internal space of the locating pin and the housing, with a tip end protruding outward from the first opening. and an unclamped position where the tip of the locating pin is accommodated within the internal space; and a band-shaped guard member that is disposed in the escape passage and extends from the side surface of the clamp arm toward the second opening. In this clamp device, the bottom surface of the escape passage is formed as a downwardly sloping surface with the second opening side facing downward when the tip of the locating pin is facing upward, and the guard member is attached to the clamp arm or the housing and forms a downwardly sloping surface that continues from the side surface of the clamp arm to the bottom surface of the escape passage. [Effects of the Invention]

[0011] According to the clamping device of the present invention, it is possible to prevent spatter from accumulating in the spatter escape passage provided in the clamping device. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a side view of a clamping device according to an embodiment of the present invention. [Figure 2] FIG. 4 is a cross-sectional view showing the clamping device in an unclamped state. [Figure 3] FIG. [Figure 4] FIG. 4 is a cross-sectional view showing a clamping state of the clamping device. [Figure 5] FIG. 2 is a perspective view of a clamp arm and a guard member. [Figure 6] FIG. 2 is an enlarged cross-sectional view of a main part of the clamping device in a clamped state. [Figure 7] FIG. 2 is an enlarged cross-sectional view of a main part of the clamping device in an unclamped state. DETAILED DESCRIPTION OF THE INVENTION

[0013] FIG. 1 is a side view of a clamping device 10 according to one embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line AA in FIG. 1. The clamping device 10 positions and clamps a panel-shaped workpiece 80. The clamping device 10 includes a locating pin 12, a housing 13, a clamping arm 14, guard members 15A and 15B, and a cylinder 16. The workpiece 80 has a clamping hole 82 for positioning, into which the locating pin 12 is inserted. As shown in FIG. 2, the clamping device 10 has escape passages 36A and 36B for discharging spatter that has entered the interior to the outside of the clamping device 10. In the following description, the locating pin 12 side of the clamping device 10 will be referred to as the tip side, and the cylinder 16 side will be referred to as the base side.

[0014] The locating pin 12 comprises a pin portion 20 that is inserted into a clamp hole 82 formed in the workpiece 80, a workpiece receiving portion 24 on which the workpiece 80 is placed, and an internal space 12a that extends from the workpiece receiving portion 24 to the pin portion 20.

[0015] The pin portion 20 is formed in a hollow cylindrical shape with a closed tip, and has a first opening in its peripheral wall that communicates with the internal space 12a of the locating pin 12. In this embodiment, the first opening is a first slit opening 21 that extends elongatedly in the axial direction of the pin portion 20, formed in the peripheral wall of the pin portion 20. The tip of the clamp arm 14 is configured to be able to protrude from this first slit opening 21 to the outside of the locating pin 12. In this embodiment, a second slit opening 22 that communicates with the internal space 12a of the locating pin 12 is formed in the peripheral wall of the pin portion 20 on the side opposite to the first slit opening 21. Note that the clamp device 10 may be configured without the second slit opening 22.

[0016] The workpiece receiving portion 24 is a cylindrical portion connected to the base end of the pin portion 20 and having a larger diameter than the pin portion 20. A workpiece receiving surface 26 that extends radially outward from the base end of the pin portion 20 is formed on the surface of the tip side of the workpiece receiving portion 24. The workpiece receiving surface 26 is the surface on which the periphery of the clamp hole 82 of the workpiece 80 is placed when the pin portion 20 is inserted into the clamp hole 82 of the workpiece 80. Note that in the locating pin 12 of this embodiment, the pin portion 20 is formed in a hollow cylindrical shape and the workpiece receiving portion 24 is formed in a rectangular cylindrical shape, but the cross-sectional shape is not limited to being circular or rectangular and can be set as appropriate.

[0017] The housing 13 is connected to the base end of the locating pin 12 and is formed in a cylindrical shape. The housing 13 has at least one second opening in its peripheral wall that communicates with the first slit opening 21 through the internal space 12a of the locating pin 12. In this embodiment, the second openings include two relief openings: a first relief opening 32A that opens in the same direction as the first slit opening 21, and a second relief opening 32B that is formed in the peripheral wall on the opposite side. As shown in FIGS. 1, 2, and 3, the housing 13 in this embodiment is formed in a cylindrical shape, having a generally rectangular cross section and surrounded by a first side surface 31a, a second side surface 31b, a third side surface 31c, and a fourth side surface 31d, and forming an internal space 13a into which the clamp arm 14 and a piston rod 66 (described later) are inserted. In the housing 13, rectangular relief openings 32A and 32B extending long in the axial direction are formed in the first side surface 31a and the third side surface 31c that face each other.

[0018] When the clamp arm 14 is attached to the housing 13, the housing 13 has therein a first escape passage 36A that connects the internal space 12a of the locating pin 12 to the first escape opening 32A, and a second escape passage 36B that connects the internal space 12a of the locating pin 12 to the second escape opening 32B. When the clamp arm 14 is removed from the housing 13, the internal space 13a of the housing 13 communicates with the first and second escape passages 36A and 36B.

[0019] A cylindrical body 38 is disposed inside the housing 13, through which the piston rod 66 of the cylinder 16 and the base end of the clamp arm 14 connected thereto are inserted. The outer surface of the tip end of the cylindrical body 38 is formed as an inclined surface that slopes from the tip of the cylindrical body 38 toward the lower ends of the escape openings 32A and 32B (the base end ends of the housing 13). This inclined surface forms the bottom surfaces 37A and 37B of the escape passages 36A and 36B. When the tip of the locating pin 12 of the clamp device 10 is facing upward, the bottom surfaces 37A and 37B are downward inclined surfaces that face the escape passages 36A and 36B downward.

[0020] In this embodiment, the locating pin 12 and the housing 13 are formed separately, but they may be formed integrally. Also, in this embodiment, the cylindrical body 38 disposed inside the housing 13 is formed separately from the housing 13, but they may be formed integrally.

[0021] The clamp arm 14 is a generally rod-shaped member disposed from the internal space 13a of the housing 13 to the internal space 12a of the locating pin 12 and extending in the axial direction of the locating pin 12. As shown in FIG. 2, the clamp arm 14 is configured to be movable between an unclamped position in which its tip is housed in the internal space 12a of the locating pin 12 and a clamped position in which its tip protrudes outward through the slit opening 21. A hook-shaped clamp portion 41 is formed at the tip of the clamp arm 14. A guide hole 44 is formed in the middle of the clamp arm 14 in the longitudinal direction. The guide hole 44 is a curved, elongated hole extending in the longitudinal direction of the clamp arm 14. A guide pin 39 fixed to the housing 13 is inserted into the guide hole 44.

[0022] 4 and 5, the clamp arm 14 is formed so that the tip end side that is housed in the locating pin 12 is thinner than the base end that is housed in the housing 13. In this embodiment, the tip end side of the clamp arm 14 is formed in a rod shape with a substantially rectangular cross section. Four side surfaces 42a, 42b, 42c, and 42d (see FIGS. 1, 2, and 5) of the clamp arm 14 are arranged to face the four side surfaces 31a, 31b, 31c, and 31d of the housing 13, respectively, and the clamp portion 41 is provided on the first side surface 42a of the clamp arm 14.

[0023] The guard members 15A, 15B are attached to the housing 13 or the clamp arm 14 and prevent foreign matter from entering the internal space 13a of the housing 13 (particularly, the internal space 38a of the cylindrical body 38 that accommodates the piston rod 66 and the base end of the clamp arm 14). As shown in FIG. 5, the guard members 15A, 15B are formed in a strip shape. The guard members 15A, 15B are disposed in the first escape passage 36A and the second escape passage 36B, respectively. The guard member 15 of this embodiment includes a first guard member 15A extending from a side surface 42a, which is the front surface of the clamp arm 14, toward the first escape opening 32A, and a second guard member 15B extending from a side surface 42c, which is the back surface of the clamp arm 14 (the side surface opposite to the side surface 42a), toward the second escape opening 32B.

[0024] In this embodiment, each guard member 15A, 15B is attached to the clamp arm 14. The first end 51 of the first guard member 15A is attached to the side surface 42a of the clamp arm 14 and extends from the side surface 42a to the bottom surface 37A of the first relief passage 36A. The second guard member 15B is attached to the side surface 42c of the clamp arm 14 and extends from the side surface 42c to the bottom surface 37B of the second relief passage 36B. The first end 51 of each guard member 15A, 15B is joined to the clamp arm 14 by welding or the like. In this embodiment, as shown in FIG. 2, the first end 51 of each guard member 15A, 15B is joined in a state where it is fitted into a fitting groove 43 provided in the side surfaces 42a, 42c of the clamp arm 14. When the clamp arm 14 and each guard member 15A, 15B are assembled to the housing 13, each guard member 15A, 15B blocks the continuity between the internal space 13a in the housing 13 into which the base of the clamp arm 14 is inserted and each escape passage 36A, 36B.

[0025] The second end portions 52 of the guard members 15A, 15B move on the bottom surfaces 37A, 37B of the escape passages 36A, 36B in accordance with the movement of the clamp arm 14. As shown in Figures 2 and 4, the lengths of the guard members 15A, 15B are set so that the second end portions 52 move within the escape passages 36A, 36B (i.e., do not protrude outside through the escape openings 32A, 32B).

[0026] The cylinder 16 constitutes a drive mechanism that applies a driving force to the clamp arm 14. As shown in FIG.

[0027] The cylinder body 60 is formed in a cylindrical shape with a bottom and arranged coaxially with the housing 13. In this embodiment, it is formed in a cylindrical shape with a substantially rectangular cross section. The internal space of the cylinder body 60 forms a cylinder chamber into which a working fluid for operating the cylinder 16 is introduced. The tip end of the cylinder body 60 is joined to the base end of the housing 13. The tip end of the cylinder body 60 is open, and this open end is closed by a lid body 61. A hole through which a piston rod 66 passes is formed in the center of the lid body 61. Two ports 62 and 63 are provided on the side of the cylinder body 60 for introducing the working fluid into the cylinder chamber and discharging the introduced working fluid. In this embodiment, compressed air is used as the working fluid.

[0028] The piston 64 is provided so as to be movable within the cylinder chamber in the axial direction of the cylinder 16, and divides the cylinder chamber into a first chamber R1 and a second chamber R2. In the illustrated example, the chamber on the tip side (housing 13 side) of the cylinder 16 is the first chamber R1, and the chamber on the base side is the second chamber R2. Of the two ports 62, 63 of the cylinder 16, the first port 62 communicates with the first chamber R1, and the second port 63 communicates with the second chamber R2. A piston rod 66 is fixed to the piston 64.

[0029] The piston rod 66 reciprocates in the axial direction in accordance with the reciprocating movement of the piston 64. A pin 67 is fixed to the tip of the piston rod 66, and the base end of the clamp arm 14 is connected to the piston rod 66 via this pin 67.

[0030] Next, the operation of the clamp device 10 will be described. In the clamp device 10, when the cylinder 16 is actuated and the piston rod 64 reciprocates in the axial direction, the clamp arm 14 connected to the piston rod 64 reciprocates accordingly. Specifically, when compressed air is introduced from the first port 62 of the cylinder 16 into the first chamber R1 and the air in the second chamber R2 is discharged from the second port 63, the piston 64, piston rod 66, and clamp arm 14 move toward the locating pin 12. When compressed air is introduced from the second port 63 into the second chamber R2 and the air in the first chamber R1 is discharged from the first port 62, the piston 64, piston rod 66, and clamp arm 14 move toward the cylinder 16. The clamp arm 14 moves while being guided in the movement direction by the guide hole 44 and the guide pin 67, and is displaced between the unclamped position shown in FIG. 2 and the clamped position shown in FIG. 4.

[0031] As shown in Fig. 6, when this clamping device 10 clamps a workpiece 80 and spot welds the workpiece 80, spatter S generated by welding may enter the interior of the clamping device 10 through the slit openings 21, 22 of the locating pin 12. The entered spatter S passes through the gap between the back surface (side surface 42c) of the clamping arm 14 and the inner peripheral surface of the locating pin 12 and enters the housing 13, but the second guard member 15B prevents the spatter S from entering the interior of the housing 13 and the spatter S is discharged from the second relief opening 32B through the second relief passage 36B to the outside of the clamping device 10. At this time, because the surface of the second guard member 15B and the bottom surface 37B of the second relief passage 36B are formed as downwardly inclined surfaces, the spatter S can be discharged to the outside of the clamping device 10 without accumulating in the second relief passage 36B.

[0032] 7, even when the clamp device 10 is in an unclamped state, spatter S may enter the interior of the clamp device 10 through the slit openings 21, 22 of the locating pin 12. In such cases, the entered spatter S passes through the gap between the front surface (side surface 42a) of the clamp arm 14 and the inner peripheral surface of the locating pin 12, and the gap between the back surface (side surface 42c) of the clamp arm 14 and the inner peripheral surface of the locating pin 12, and enters the housing 13. The entered spatter S is prevented from entering the interior of the housing 13 by guard members 15A, 15B, and is discharged to the outside of the clamp device 10 through the first escape passage opening 32A or the second escape opening 32B. In this case, since the surfaces of the guard members 15A, 15B and the bottom surfaces 37A, 37B of the first and second escape passages 36A, 36B are formed as downwardly inclined surfaces, the spatter S can be discharged to the outside of the clamping device 10 without being deposited in each escape passage 36A, 36B.

[0033] As described above, when spatter S enters the inside of the clamp device 10, the clamp device 10 of this embodiment can discharge the spatter S to the outside of the housing 13 while preventing the spatter S from accumulating in the escape passages 36A and 36B. This eliminates the need to remove the spatter S accumulated inside the clamp device 10 with compressed air.

[0034] Furthermore, in the above-described clamp device 10, guard members 15A, 15B move in conjunction with the movement of clamp arm 14, so that spatters S adhering to the surfaces of guard members 15A, 15B can be efficiently removed. At this time, second end portions 52 of guard members 15A, 15B move over bottom surfaces 37A, 37B of escape passages 36A, 36B, so that spatters S adhering to bottom surfaces 37A, 37B can be scraped off by second end portions 52.

[0035] Furthermore, because guard members 15A, 15B have spring properties, they can be flexibly deformed to follow the movement of clamp arm 14. This makes it possible to maintain good clamping and unclamping operations of clamp arm 14. Furthermore, the elastic deformation of guard members 15A, 15B can prevent spatters S from adhering to guard members 15A, 15B.

[0036] The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit of the invention.

[0037] For example, the guard members 15A, 15B may be configured such that the second end 52 is joined to the bottom surfaces 37A, 37B of the escape passages 36A, 36B, and the first end 51 is in contact with the clamp arm 14 in a non-jointed state. [Explanation of symbols]

[0038] 10 Clamping device 12 Locating Pins 12a Locating pin internal space 13. Housing 13a Housing internal space 14 Clamp arm 15A First guard member 15B Second guard member 16 cylinders 20-pin section 21 First slit opening 22 Second slit opening 24 Workpiece receiving part 26 Work receiving surface 32A First relief opening 32B Second relief opening 36A First relief passage 36B Second escape passage 37A Bottom of the first relief passage 37B Bottom of second relief passage 80 Work 82 Clamp hole S Spatter

Claims

1. a locating pin having a pin portion inserted into a clamp hole formed in a panel-shaped workpiece, and a workpiece receiving surface extending radially outward from a base end of the pin portion, the locating pin having a first opening formed in a peripheral wall of the pin portion that communicates with an internal space; a cylindrical housing connected to a base end of the locating pin, the housing having a second opening in a peripheral wall and an escape passage communicating the second opening with an internal space of the locating pin; a clamp arm that is disposed in the locating pin and in an internal space of the housing, the clamp arm being displaceable between a clamping position in which a tip portion thereof protrudes outward from the first opening and can clamp the workpiece placed on the workpiece receiving surface, and an unclamping position in which the tip portion thereof is accommodated within the internal space; a band-shaped guard member disposed in the escape passage and extending from a side surface of the clamp arm toward the second opening; In a clamping device comprising: a bottom surface of the relief passage is formed as a downwardly inclined surface with the second opening side facing downward when the tip of the locating pin faces upward, The clamp device is characterized in that the guard member is attached to the clamp arm or the housing and has a downwardly sloping surface that continues from the side surface of the clamp arm to the bottom surface of the escape passage.

2. 2. The clamp device according to claim 1, wherein a first end of the guard member is attached to a side surface of the clamp arm, and a second end of the guard member moves on the bottom surface of the escape passage as the clamp arm is displaced.

3. 3. The clamp device according to claim 2, wherein the second end of the guard member moves within a range within the escape passage.

4. the second opening has a first relief opening that opens in the same direction as the first opening in the circumferential direction of the housing, and a second relief opening that is formed in the peripheral wall on the opposite side to the first relief opening, the relief passage includes a first relief passage that communicates an internal space of the locating pin with the first relief opening, and a second relief passage that communicates an internal space of the locating pin with the second relief opening, The clamp device according to any one of claims 1 to 3, characterized in that the guard member comprises a first guard member extending from the side surface of the clamp arm on the first escape opening side to the bottom surface of the first escape passage, and a second guard member extending from the side surface of the clamp arm on the second escape opening side to the bottom surface of the second escape passage.

5. 4. The clamp device according to claim 1, wherein the guard member is formed of a leaf spring.

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