Gripping device

Abstract

To provide a gripping device that can be elongated in a service life.SOLUTION: A gripping device 100 comprises a housing 10, a guide member 20, a pair of gripping members 30, a pair of levers 40, a driving shaft 50 and a roller member 70. The driving shaft 50 is connected to the pair of gripping members 30 through the pair of levers 40, at one end part thereof and is mounted with the roller member 70, at the other end part. The gripping device 100 is driven by an external driving source. The external driving source drives the driving shaft 50 through the roller member 70. A load in an axial direction X generated by the external driving source is transmitted to the drive shaft through a support part 71 and a rotating part 72 which the roller member 70 has. A load in a direction orthogonal to the axial direction X generated by the external driving source is absorbed by rotation of the rotating part 72.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a gripping device. [Background technology]

[0002] Conventionally, a gripping device having a pair of gripping members driven by an external drive source has been known. The gripping device has a housing, a pair of gripping members, a pair of levers, and a drive shaft. In the gripping device, the drive shaft is reciprocated within the housing by the external drive source, and this reciprocating movement opens and closes the pair of gripping members via the pair of levers. The gripping device grips an object using the pair of gripping members. For example, Patent Document 1 discloses a fluid pressure hand, which is a gripping device, having a pair of master jaws, which are a pair of gripping members. In the fluid pressure hand, a piston, which is a drive shaft, is operated by fluid pressure supplied from outside to a body, which is a housing, to open and close the pair of master jaws. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-300674 Summary of the Invention [Problem to be solved by the invention]

[0004] An example of an external driving source that drives the drive shaft is a cam rotated by a driving shaft. The driving shaft extends in a direction perpendicular to the axial direction of the drive shaft and rotates the cam. The rotating cam moves the drive shaft in the axial direction in accordance with the shape of the cam by fitting the end of the drive shaft along the outer peripheral surface of the cam. However, in addition to the axial load, a lateral load is generated on the drive shaft due to friction between the drive shaft and the rotating cam. The lateral load applied to the drive shaft is applied in a direction perpendicular to both the axial direction of the drive shaft and the direction in which the driving shaft extends. The lateral load applied to the drive shaft applies a load to the pair of levers and the pair of gripping members. As a result, the lateral load may shorten the life of the gripping device. [Means for solving the problem]

[0005] A gripping device for solving the above problem includes a housing defining a through hole penetrating in the axial direction, a guide member provided at one end of the housing in the axial direction, a pair of gripping members that move along the guide member in a direction perpendicular to the axial direction, a pair of levers connected to the pair of gripping members, and a drive shaft that is inserted into the through hole and has a connecting end that connects to the pair of levers and a drive end that protrudes from the other end of the housing, and the pair of gripping members open and close in a direction perpendicular to the axial direction in conjunction with the reciprocating movement of the drive shaft along the axial direction, and the drive shaft has a roller member at the driving end, and the roller member has a rotating part that is fixed to the driving end and is supported by a support part so as to be rotatable about an axis extending in a direction perpendicular to the axial direction.

[0006] In the above gripping device, the drive shaft has a first rod member having the connecting end at one end and a fixed end at the other end, and a second rod member having the driving end at one end and a connecting end at the other end, and the fixed end and the connecting end may be connected by a holding member.

[0007] In the above-mentioned holding device, the second rod member has a flange portion near the connection end, and the holding member defines a holding chamber that opens in a direction perpendicular to the axial direction, and the holding member is fixed to the fixed end and holds the flange portion in the holding chamber so that the second rod member can rotate around an axis extending in the axial direction.

[0008] In the above-mentioned gripping device, a rotation control member is fixed to the other end of the housing, and the second rod member has an engagement plane parallel to the axial direction on at least a portion of its outer surface and is inserted into an insertion hole defined by the rotation control member, and the rotation control member has a hole defining surface that defines the insertion hole, and the hole defining surface may have an engaged plane facing the engagement plane.

[0009] In the above-mentioned gripping device, a rotation-restricting member having a bearing is fixed to the other end of the housing, and the second rod member has an engagement plane parallel to the axial direction on at least a portion of its outer surface and is inserted into a bearing hole defined by the bearing, and the bearing has a bearing hole-defining surface that defines the bearing hole, and the bearing hole-defining surface may have an engaged plane facing the engagement plane. [Effects of the Invention]

[0010] According to the present invention, the life of the gripping device can be extended. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a cross-sectional view of a gripping device. [Figure 2] FIG. 2 is a cross-sectional view taken along line 2-2 in FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along line 3-3 in FIG. [Figure 4] FIG. 4 is a diagram showing a gripping device. [Figure 5]FIG. 5 is a cross-sectional view showing the operation of the gripping device. [Figure 6] FIG. 6 is a cross-sectional view of a gripping device according to a modified example. [Figure 7] FIG. 7 is a diagram showing a gripping device and an inclined surface in a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, one embodiment of the gripping device will be described with reference to FIGS. <Overall image of the gripping device> As shown in FIG. 1, the gripping device 100 includes a housing 10, a guide member 20, a pair of gripping members 30, a pair of levers 40, a drive shaft 50, and a rotation restricting member 80.

[0013] <Housing> The housing 10 has a rectangular cylindrical shape that extends from a first end to a second end and has a circular hole formed therein when viewed in the axial direction. Hereinafter, the axis of the housing 10 will be referred to as the central axis L. The direction in which the central axis L extends will be referred to as the axial direction X. In other words, the direction in which the housing 10 extends is the axial direction X. The housing 10 has, at its first end, a first housing end face 11 that is perpendicular to the central axis L of the housing 10. The housing 10 also has, at its second end, a second housing end face 12 that is perpendicular to the central axis L of the housing 10. The second housing end face 12 is the opposite face of the first housing end face 11 in the axial direction X.

[0014] The housing 10 has a housing inner surface 13. The housing inner surface 13 is composed of a first housing inner circumferential surface 14 and a second housing inner circumferential surface 15. The housing 10 has the first housing inner circumferential surface 14 in a portion of the housing inner surface 13 closer to the first housing end face 11. The first housing inner circumferential surface 14 is connected to the first housing end face 11. The housing 10 has a second housing inner circumferential surface 15 in a portion of the housing inner surface 13 closer to the second housing end face 12 than the first housing inner circumferential surface 14. The second housing inner circumferential surface 15 is connected to the second housing end face 12.

[0015] The first housing inner peripheral surface 14 defines a first housing through hole 14a. The first housing through hole 14a opens at the first housing end face 11. The second housing inner peripheral surface 15 defines a second housing through hole 15a. The second housing through hole 15a opens at the second housing end face 12. The first housing through hole 14a and the second housing through hole 15a communicate with each other inside the housing 10. The first housing through hole 14a and the second housing through hole 15a form a housing hole 10a that serves as a through hole that penetrates the housing 10. In other words, the housing 10 defines the housing hole 10a that penetrates in the axial direction X.

[0016] The diameter of the first housing through-hole 14a is larger than the diameter of the second housing through-hole 15a. In other words, the inner diameter of the portion of the housing 10 that has the first housing inner circumferential surface 14 is larger than the inner diameter of the portion that has the second housing inner circumferential surface 15.

[0017] A spring mounting portion 13b is provided on the first housing inner circumferential surface 14 in a portion closer to the second housing end surface 12. The inner diameter of the housing 10 at the spring mounting portion 13b is smaller than the inner diameter at the second housing inner circumferential surface 15.

[0018] <Guide parts> The guide member 20 is shaped like a block with its longitudinal axis extending in one direction. The guide member 20 has a first guide surface 21 and a second guide surface 22 that are surfaces parallel to the longitudinal direction of the guide member 20. The second guide surface 22 is the surface of the outer surface of the guide member 20 opposite to the first guide surface 21 in the direction perpendicular to the longitudinal direction of the guide member 20.

[0019] A guide groove 23 is formed in the first guide surface 21 of the guide member 20. The guide groove 23 is a groove-like groove that opens in the first guide surface 21 in a direction from the second guide surface 22 toward the first guide surface 21. The guide groove 23 is formed in the first guide surface 21 over the entire longitudinal direction of the guide member 20. The guide groove 23 is defined by a pair of guide groove side surfaces 23a and a guide groove bottom surface 23b. Each of the pair of guide groove side surfaces 23a is a surface that connects the first guide surface 21 and the guide groove bottom surface 23b. Note that in FIG. 1, only one of the pair of guide groove side surfaces 23a is shown, and the other surface is not shown.

[0020] A pair of lever holes 24a are formed in the guide member 20. Each of the pair of lever holes 24a is open to the second guide surface 22 and the guide groove bottom surface 23b. Each of the pair of lever holes 24a is an elongated hole having a major axis in the extension direction of the guide member 20.

[0021] The guide member 20 is provided on the housing 10 so that the second guide surface 22 faces the first housing end surface 11. In other words, the guide member 20 is provided on the housing 10 so that the direction in which the guide member 20 extends is perpendicular to the axial direction X. The guide member 20 is provided on the housing 10 so that each of the pair of lever holes 24a communicates with the first housing through-hole 14a.

[0022] <Gripping member> Each of the pair of gripping members 30 has a gripping base 31 and a hand portion 32. The gripping base 31 is in the shape of a block whose longitudinal direction extends in the longitudinal direction of the guide member 20. The hand portion 32 is provided upright on the gripping base 31.

[0023] Each of the pair of gripping members 30 has a connecting hole 31b formed in the surface facing the guide groove bottom surface 23b. In the gripping device 100, each of the pair of gripping members 30 is provided in the guide groove 23. Each of the pair of gripping members 30 is attached so that the gripping base 31 is movable along the direction in which the guide groove 23 extends. The pair of gripping members 30 open and close along the guide member 20. The pair of gripping members 30 move linearly along the guide groove 23. In other words, the guide member 20 functions as a linear guide for the pair of gripping members 30.

[0024] Each of the pair of gripping members 30 is provided on the guide member 20 so that the connecting hole 31b communicates with each of the lever holes 24a. The diameter of each connecting hole 31b is smaller than the opening width in the longitudinal direction of each of the pair of lever holes 24a. Each of the pair of gripping members 30 is movable within the range in which the connecting hole 31b communicates with each of the lever holes 24a.

[0025] <Lever> Each of the pair of levers 40 has a first lever-forming member 41, a second lever-forming member 42, and a connecting portion 43.

[0026] The first lever-forming member 41 is in the form of a long plate having a longitudinal direction from the first end to the second end. The first lever-forming member 41 has an engaging element 44 at the first end. The engaging element 44 is spherical.

[0027] The second lever-forming member 42 is a long plate having a longitudinal direction from the first end to the second end. A through-hole is formed in the second lever-forming member 42 in a portion near the second end. The through-hole penetrates the second lever-forming member 42 in the thickness direction.

[0028] Each of the pair of levers 40 is formed by a first lever-forming member 41 and a second lever-forming member 42 being integrated by a connecting portion 43. In each of the pair of levers 40, a portion of the first lever-forming member 41 near the second end and a portion of the second lever-forming member 42 near the first end are connected by the connecting portion 43. The first lever-forming member 41 is connected to the second lever-forming member 42 at the connecting portion 43 so that the longitudinal direction of the first lever-forming member 41 is perpendicular to the longitudinal direction of the second lever-forming member 42. Note that the longitudinal direction of the first lever-forming member 41 and the longitudinal direction of the second lever-forming member 42 do not have to be perpendicular. It is preferable that the longitudinal direction of the first lever-forming member 41 and the longitudinal direction of the second lever-forming member 42 are perpendicular to each other and that each of the pair of levers 40 is L-shaped.

[0029] The pair of levers 40 has the first end-side portions of the first lever-forming member 41 inserted into the pair of lever holes 24a, respectively, and the engaging element 44 inserted into the connecting hole 31b. In other words, each of the pair of levers 40 is connected to the gripping member 30. The first lever-forming member 41 can swing in each of the pair of lever holes 24a in the longitudinal direction of the lever hole 24a.

[0030] The engaging piece 44 is rotatable inside the connecting hole 31b while the outer surface of the engaging piece 44 is in sliding contact with the surface that defines the connecting hole 31b. Each of the pair of levers 40 is accommodated in the first housing through-hole 14a. The pair of levers 40 are arranged side by side in the thickness direction of the second lever-forming member 42. The pair of levers 40 are arranged such that portions of the second lever-forming members 42 near the second ends overlap in the thickness direction of the second lever-forming member 42. Each of the pair of levers 40 is accommodated in the first housing through-hole 14a so that the second lever-forming member 42 can swing around a through-hole formed in the portion near the second end as a swing center. Each of the pair of levers 40 is provided in the first housing through-hole 14a so that the through-hole formed in the portion near the second end is on the central axis L when viewed in the thickness direction of the second lever-forming member 42.

[0031] <Overall configuration of drive shaft> The drive shaft 50 is formed by a first rod member 51, a second rod member 52, and a holding member 60. The first rod member 51 and the second rod member 52 are connected by the holding member 60 so as to be capable of transmitting power.

[0032] <First rod member> The first rod member 51 has a cylindrical shape extending from a first end to a second end in the direction along which its axis extends. The first rod member 51 has a connecting end 50a at the first end and a fixed end 50c at the second end. In other words, the first rod member 51 has the connecting end 50a at one end in the direction along which its axis extends and the fixed end 50c at the other end. The first rod member 51 has a lever holding portion 54 in a portion close to the connecting end 50a. The lever holding portion 54 has a lever pin 54a. The lever pin 54a extends in a direction perpendicular to the axis of the first rod member 51. A male thread is formed in a portion of the first rod member 51 close to the fixed end 50c.

[0033] <Second rod member> The second rod member 52 has a cylindrical shape extending from a first end to a second end in the direction of its axis. The second rod member 52 has a connecting end 50d at its first end and a driving end 50b at its second end. In other words, the second rod member 52 has the driving end 50b at one end and the connecting end 50d at the other end.

[0034] The second rod member 52 has a flange portion 55 and a rod portion 56. The flange portion 55 is a portion of the second rod member 52 closer to the connection end 50d. The flange portion 55 is disk-shaped with its thickness direction aligned with the axis of the second rod member 52. The rod portion 56 is a portion of the second rod member 52 closer to the driving end 50b than the flange portion 55. In other words, the rod portion 56 is a portion of the second rod member 52 that is different from the flange portion 55. The flange portion 55 has a flange outer peripheral surface 55a. The diameter of the flange portion 55 is larger than the diameter of the rod portion 56. The second rod member 52 bulges out from the rod portion 56 at the flange portion 55.

[0035] As shown in FIG. 3 , a pair of engagement planes 56b are formed on the outer surface of the rod portion 56. Each of the pair of engagement planes 56b is parallel to the axis of the rod portion 56. Each of the pair of engagement planes 56b is formed on a portion of the outer surface of the rod portion 56 in the circumferential direction of the rod portion 56. The pair of engagement planes 56b are formed at positions where one is opposite the other in a direction perpendicular to the axis of the rod portion 56. In other words, the cross-sectional shape of the rod portion 56 as viewed in the direction of the axis is a two-flat shape formed by the pair of engagement planes 56b. Therefore, the second rod member 52 has engagement planes 56b on at least a portion of its outer surface. In this embodiment, the second rod member 52 has two engagement planes 56b. As will be described later, the pair of engagement planes 56b formed on the rod portion 56 function as a rotation stopper that restricts rotation of the rod portion 56 relative to the housing 10.

[0036] <Retaining member> The holding member 60 has a cylindrical shape extending from a first end to a second end in the direction along the axis. The holding member 60 has a connecting cylindrical portion 61 in a cylindrical portion closer to the first end in the direction along the axis, and a holding flange portion 62 in a portion closer to the second end than the connecting cylindrical portion 61. The outer diameter of the holding member 60 is larger at the holding flange portion 62 than at the connecting cylindrical portion 61. In other words, the outer diameter of the holding flange portion 62 is larger than the outer diameter of the holding member 60 at a portion other than the holding flange portion 62.

[0037] The holding member 60 has a first holding end face 63 on the end face of the connecting tube portion 61 in the direction in which the axis extends, and has a second holding end face 64 on the end face of the holding flange portion 62. The first holding end face 63 is the opposite face to the second holding end face 64 in the direction in which the axis of the holding member 60 extends.

[0038] The connecting cylindrical portion 61 has an internal thread formed on its inner peripheral surface. A holding portion through-hole 60a is formed in the holding member 60. The holding portion through-hole 60a extends in the direction of the axis of the holding member 60 and penetrates the holding member 60. The diameter of the holding portion through-hole 60a is the same in each of the first holding end face 63 and the second holding end face 64. The diameter of the holding portion through-hole 60a is enlarged in the portion defined by the holding flange portion 62. In other words, the inner diameter of the portion of the holding member 60 having the holding flange portion 62 is larger than the inner diameter of the portion other than the holding flange portion 62.

[0039] A retaining chamber 62a is formed in the retaining flange 62. The retaining chamber 62a opens at a portion of the outer peripheral surface of the retaining flange 62 in the circumferential direction of the retaining flange 62. The retaining chamber 62a extends in the radial direction of the retaining member 60. The retaining chamber 62a communicates with the retaining portion through-hole 60a inside the retaining member 60. A portion of the retaining chamber 62a coincides with a portion of the retaining portion through-hole 60a defined by the retaining flange 62. In other words, the retaining portion through-hole 60a expands in the radial direction of the retaining flange 62 at the portion coinciding with the retaining chamber 62a. The opening width in the circumferential direction of the retaining flange 62 at the outer peripheral surface of the retaining flange 62 is larger than the diameter of the retaining portion through-hole 60a at the second retaining end face 64. Furthermore, the opening width is larger than the diameter of the second rod member 52.

[0040] As shown in Fig. 2, among the surfaces that define the retaining chamber 62a, the inner surface that is parallel to the thickness direction of the retaining flange portion 62 is composed of a passage-defining surface 62b and a retaining flange inner circumferential surface 62c. The passage-defining surface 62b is connected to the outer circumferential surface of the retaining flange portion 62 and is a flat surface that extends from the opening edge of the outer circumferential surface into the interior of the retaining flange portion 62. The retaining flange inner circumferential surface 62c is hemispherical and connected to the passage-defining surface 62b. The retaining flange inner circumferential surface 62c is connected to the outer circumferential surface of the retaining flange portion 62 via the passage-defining surface 62b.

[0041] A portion of the holding flange 62 is cut out closer to the second holding end face 64 than the holding chamber 62a in the direction in which the axis of the holding member 60 extends. Due to this cutout, the holding chamber 62a opens closer to the second holding end face 64 than the holding chamber 62a. In other words, the holding chamber 62a communicates with the outside of the holding member 60 in the direction in which the axis of the holding member 60 extends and in the direction from the second holding end face 64 toward the first holding end face 63. In other words, the holding chamber 62a opens at the outer peripheral surface of the holding flange 62, and also opens at the second holding end face 64 due to the cutout in the holding flange 62. The opening width at the second holding end face 64 due to the cutout is smaller than the opening width of the holding chamber 62a at the outer peripheral surface of the holding flange 62.

[0042] <Integration of the first rod member, the second rod member, and the holding member> As shown in FIGS. 1 and 2, the drive shaft 50 is formed by integrating a first rod member 51, a second rod member 52, and a holding member 60. In the drive shaft 50, the axis of the first rod member 51, the axis of the second rod member 52, and the axis of the holding member 60 are aligned. A first end of the drive shaft 50 is aligned with the connecting end 50a of the first rod member 51. A second end of the drive shaft 50 is aligned with the driving end 50b of the second rod member 52. In other words, the drive shaft 50 has the connecting end 50a at one end and the driving end 50b at the other end. The drive shaft 50 is columnar and extends from the connecting end 50a to the driving end 50b. The drive shaft 50 is formed by arranging the first rod member 51, the holding member 60, and the second rod member 52 in this order from the connecting end 50a to the driving end 50b. The rod portion 56 has a pair of engagement planes 56b, each of which is perpendicular to the axial direction X.

[0043] The first rod member 51 is integrated with the holding member 60 by threading a male thread formed in a portion closer to the fixed end 50c into a female thread formed portion of the connecting tube portion 61. In other words, the first rod member 51 is threadedly engaged with the holding member 60. That is, the holding member 60 is fixed to the fixed end 50c.

[0044] The radial direction of the holding flange portion 62 is perpendicular to the axial direction X. In other words, the holding member 60 defines a holding chamber 62a that opens in a direction perpendicular to the axial direction X. The second rod member 52 is integrated with the holding member 60 by inserting the flange portion 55 into the holding chamber 62a from the radial outside of the holding member 60. The diameter of the flange portion 55 is slightly smaller than the opening width of the holding chamber 62a on the outer circumferential surface of the holding flange portion 62. The diameter of the flange portion 55 is also larger than the opening width of the second holding end face 64 formed by the notch. The flange portion 55 is inserted into the holding chamber 62a with the rod portion 56 protruding from the notch in the holding flange portion 62. In other words, when the flange portion 55 is inserted into the holding chamber 62a, the rod portion 56 protrudes from the notch in the holding flange portion 62. The flange portion 55 is inserted into the holding chamber 62a with the flange portion outer peripheral surface 55a aligned with the passage defining surface 62b.

[0045] The flange portion 55 moves radially of the holding flange portion 62 until the rod portion 56 reaches a position where the axis of the second rod member 52 and the axis of the holding member 60 are aligned. When the axis of the second rod member 52 and the axis of the holding member 60 are aligned, the holding flange inner circumferential surface 62c faces the flange outer circumferential surface 55a. The radius of curvature of the holding flange inner circumferential surface 62c is the same as the radius of curvature of the flange outer circumferential surface 55a. In other words, the holding member 60 holds the second rod member 52 in the holding chamber 62a so that the flange portion 55 is rotatable.

[0046] When the second rod member 52 is in this position, the flange portion 55 closes the holding portion through-hole 60a in the direction in which the axis of the holding member 60 extends. In other words, the diameter of the flange portion 55 is larger than the diameter of the holding portion through-hole 60a in each of the first holding end face 63 and the second holding end face 64. Each of the two end faces of the flange portion 55 in the thickness direction faces a surface that defines the holding chamber 62a and is perpendicular to the axis of the holding member 60. In other words, the second rod member 52 is integrated with the holding member 60 by the engagement of the flange portion 55 and the holding flange portion 62 in the direction in which the axis of the second rod member 52 extends.

[0047] In the drive shaft 50, the second rod member 52 is rotatable around the axis of the second rod member 52 and the holding member 60. In other words, the holding member 60 holds the second rod member 52 so that the second rod member 52 is rotatable around the axis. Therefore, the second rod member 52 is connected to the first rod member 51 by the holding member 60 so that the second rod member 52 is rotatable relative to the first rod member 51. Furthermore, in the drive shaft 50, the fixed end 50c and the connecting end 50d are positioned opposite each other inside the holding member 60. The fixed end 50c and the connecting end 50d are connected by the holding member 60.

[0048] As shown in FIG. 1, in the gripping device 100, the drive shaft 50 is provided in the housing 10 so that the axis of the drive shaft 50 coincides with the central axis L of the housing 10. The drive shaft 50 is inserted into the first housing through-hole 14a with the driving end 50b protruding from the second housing end face 12. In other words, the drive shaft 50 is inserted into the housing through-hole 10a. Furthermore, a guide member 20 is provided at one end of the housing 10 in the axial direction X, and the driving end 50b protrudes from the other end. The connecting end 50a of the drive shaft 50 is accommodated in the first housing through-hole 14a. The lever holding portion 54 is accommodated in the first housing through-hole 14a.

[0049] The drive shaft 50 is connected to each of the pair of levers 40 by a lever holding portion 54. In other words, the drive shaft 50 has a connecting end 50a that connects to the pair of levers 40. Each of the pair of levers 40 is connected to the drive shaft 50 at a portion of the second lever-forming member 42 near the second end. Each of the pair of levers 40 is connected to the lever holding portion 54 by inserting a lever pin 54a into a through-hole formed in the second lever-forming member 42 near the second end. Each of the pair of levers 40 can swing relative to the drive shaft 50 around the lever pin 54a as a swing center. Each of the pair of levers 40 moves in conjunction with the drive shaft 50. Furthermore, each of the pair of gripping members 30 moves in conjunction with each of the pair of levers 40 to which the gripping member 30 is connected. In other words, each of the pair of gripping members 30 moves in conjunction with the drive shaft 50.

[0050] A portion of the first rod member 51 is surrounded by the spring mounting portion 13b. The diameter of the hole defined by the spring mounting portion 13b is larger than the diameter of the first rod member 51. An elastic member 16 made of a coil spring is provided in the spring mounting portion 13b. The elastic member 16 surrounds the first rod member 51. In other words, the first rod member 51 is inserted through the elastic member 16. One end of the elastic member 16 is fixed to the spring mounting portion 13b, and the other end is fixed to the holding flange portion 62. The elastic member 16 biases the holding member 60 in a direction from the first housing end face 11 toward the second housing end face 12. In other words, the elastic member 16 biases the drive shaft 50 in the axial direction X.

[0051] <Roller member> 4, the drive shaft 50 has a roller member 70. The roller member 70 has a support portion 71 and a rotating portion 72. The support portion 71 has a rotating shaft 70a and a fixed member 70b.

[0052] The support portion 71 has a support base 73 and a pair of support side walls 74. The support base 73 is block-shaped. The support base 73 has a first support base surface 73a and a second support base surface 73b. The first support base surface 73a is the outer surface of the support base 73 opposite the second support base surface 73b.

[0053] Each of the pair of support side walls 74 is plate-shaped. A roller pin hole 74c is formed in the support side wall 74, penetrating the thickness direction. Each of the pair of support side walls 74 is erected on the second support base surface 73b of the support base 73. More specifically, each of the pair of support side walls 74 is erected on the second support base surface 73b so that the thickness direction of each of the pair of support side walls 74 is parallel to the second support base surface 73b. The pair of support side walls 74 are provided on the support base 73 so as to be spaced apart from each other in the thickness direction. The pair of support side walls 74 are provided on the support base 73 so that the roller pin holes 74c of each support side wall 74 are aligned in the thickness direction when viewed from the thickness direction of each support side wall 74.

[0054] A roller holding chamber 71a is defined in the support portion 71. The roller holding chamber 71a is defined by a support base 73 and a pair of support side walls 74. The roller holding chamber 71a communicates with the outside of the support portion 71 in a direction from the first support base surface 73a toward the second support base surface 73b, and in a direction perpendicular to this direction and a direction parallel to each support side wall 74.

[0055] The rotating portion 72 is cylindrical. A rotating portion through-hole 72a is formed in the rotating portion 72. In the roller member 70, the rotating portion 72 is supported by the support portion 71. The support portion 71 holds the rotating portion 72 in the roller holding chamber 71a so that the thickness direction of each of the pair of support side walls 74 is parallel to the direction in which the axis of the rotating portion 72 extends. In the roller holding chamber 71a, the rotating portion through-hole 72a of the rotating portion 72 and the pair of roller pin holes 74c are aligned on a straight line. The roller member 70 is formed by inserting a rotating shaft 70a through the rotating portion through-hole 72a and the pair of roller pin holes 74c, and fixing the rotating shaft 70a to each of the pair of support side walls 74 by fixing members 70b. The rotating portion 72 is supported by the support portion 71 so as to be rotatable about the axis of the rotating shaft 70a. The rotation shaft 70a may be fixed to only one of the pair of support side walls 74. In this case, the support portion 71 may have only one of the pair of support side walls 74.

[0056] As shown in FIG. 1 , in the gripping device 100, the roller member 70 is fixed to the drive end 50b. More specifically, the roller member 70 is attached to the drive end 50b by fixing a support portion 71 to the drive shaft 50. That is, the drive shaft 50 has the roller member 70 at the drive end 50b. The support portion 71 is provided at the drive end 50b so that the direction from the connecting end 50a toward the drive end 50b coincides with the direction from the first support base surface 73a toward the second support base surface 73b. In this case, the axis of the rotation shaft 70a is perpendicular to the axis of the drive shaft 50. Therefore, the support portion 71 is fixed to the drive end 50b and has the rotation shaft 70a extending in a direction perpendicular to the axial direction X.

[0057] <Rotation restriction members and bearings> As shown in FIGS. 1 and 3, the rotation restricting member 80 is fixed to the second housing end face 12. The rotation restricting member 80 has a rectangular cylindrical shape. The rotation restricting member 80 is provided on the second housing end face 12 so that the axis of the housing 10 and the axis of the rotation restricting member 80 coincide with each other. The rotation restricting member 80 has a hole-defining surface 84. The hole-defining surface 84 defines a restricting insertion hole 80a. In other words, the rotation restricting member 80 has a restricting insertion hole 80a. The restricting insertion hole 80a is open on both end faces in the direction in which the axis of the rotation restricting member 80 extends. The rotation restricting member 80 is provided on the second housing end face 12 so that the second housing through-hole 15a and the restricting insertion hole 80a are in communication with each other.

[0058] The gripping device 100 has a bearing 90 fixed to the rotation restricting member 80. The bearing 90 is fixed to the hole defining surface 84. In other words, the bearing 90 is housed in the restricting insertion hole 80a. The axis of the bearing 90 coincides with the axis of the rotation restricting member 80. The bearing 90 has a bearing hole defining surface 91. The bearing hole defining surface 91 defines the bearing hole 90a. The bearing hole 90a is a part of the restricting insertion hole 80a.

[0059] A pair of flat engaged surfaces 91a are formed on a portion of the bearing hole defining surface 91 in the circumferential direction of the bearing 90. Each of the pair of flat engaged surfaces 91a is parallel to the axis of the bearing 90. Each of the pair of flat engaged surfaces 91a is parallel to another flat engaged surface 91a that is different from the flat engaged surface 91a. In other words, the pair of flat engaged surfaces 91a are parallel to each other.

[0060] In the gripping device 100, the drive shaft 50 is inserted through the restriction insertion hole 80a and the bearing hole 90a, and has a driving end 50b protruding from the rotation restriction member 80 and the bearing 90. The drive shaft 50 is also inserted through the bearing hole 90a so that a bearing hole defining surface 91 faces the outer surface of the rod portion 56. Each of the pair of engaging flat surfaces 56b and each of the pair of engaged flat surfaces 91a face each other in the bearing hole 90a. In other words, the bearing hole defining surface 91 has an engaged flat surface 91a facing the engaging flat surface 56b. The drive shaft 50 is inserted through the rotation restriction member 80 and the bearing 90 so as to be reciprocable in the axial direction X along the bearing hole defining surface 91.

[0061] <Operation of the gripping device> As shown in FIG. 5, the gripping device 100 is driven by a cam C that rotates together with the motor shaft M. That is, in this embodiment, the cam C is an external drive source. The motor shaft M is rotated by a motor (not shown). The cam C is plate-shaped. Furthermore, the cam C has a generally oval shape with a radially outwardly bulging outer circumferential surface in a radially outward portion. The cam C is fixed to the motor shaft M. The cam C is interlocked with the motor shaft M. The motor shaft M rotates around its axis. That is, the cam C rotates around the axis of the motor shaft M in accordance with the rotation of the motor shaft M.

[0062] The gripping device 100 is provided at a position where the outer peripheral surface of the cam C and the outer peripheral surface of the rotating part 72 come into contact with each other. That is, the gripping device 100 receives power from the cam C via the roller member 70 and transmits it to the drive shaft 50. For example, the housing 10 of the gripping device 100 is fixed to a rail or the like (not shown). The motor shaft M is fixed to the rail. That is, the gripping device 100 does not change the relative positional relationship between the housing 10 and the motor shaft M during operation.

[0063] The gripping device 100 is provided at a position where the axis of the motor shaft M is perpendicular to the central axis L. In other words, the gripping device 100 is provided so that the direction in which the cam C rotates and the direction in which the rotating part 72 rotates coincide with each other.

[0064] 5 shows the operation of the gripping device 100. Because the cam C has a substantially oval shape, the drive shaft 50 moves in the axial direction X as the cam C rotates. In other words, the cam C rotates while in contact with the rotating part 72, thereby moving the drive shaft 50 in the axial direction X. The rotation of the cam C leads to the rotation of the rotating part 72 simultaneously with the movement of the drive shaft 50. The rotating part 72 rotates around the axis of the rotating shaft 70a. The rotation of the rotating part 72 is caused by the frictional force between the cam C and the rotating part 72.

[0065] As the driving end 50b moves relative to the housing 10, the connecting end 50a moves in accordance with the amount of movement of the driving end 50b. As the connecting end 50a moves in the axial direction X, each of the pair of levers 40 moves. The movement of each of the pair of levers 40 guides the movement of each of the pair of gripping members 30 in a direction along the guide member 20. When the driving end 50b moves in a direction from the second housing end face 12 toward the first housing end face 11, the gripping device 100 moves in a direction that opens each of the pair of gripping members 30. At this time, the holding member 60 moves in a direction approaching the pair of levers 40, and the elastic member 16 is compressed.

[0066] When the gripping device 100 opens the pair of gripping members 30, the compressed elastic member 16 biases the holding member 60 in a direction from the first housing end face 11 to the second housing end face 12. As a result, the load in the axial direction X applied from the cam C to the drive end 50b weakens, and the drive shaft 50 moves in a direction from the first housing end face 11 to the second housing end face 12 due to the biasing force of the elastic member 16. In other words, the elastic member 16 biases the drive shaft 50 in a direction from one end to the other end in the axial direction X. When the drive shaft 50 moves in this direction, the gripping device 100 moves in a direction to close the pair of gripping members 30. Therefore, the elastic member 16 moves the drive shaft 50 in a direction to close the pair of gripping members 30. The gripping device 100 opens and closes the pair of gripping members 30 in conjunction with the movement of the drive shaft 50 from one end to the other end due to the biasing force of the elastic member 16.

[0067] As described above, the gripping device 100 opens and closes the pair of gripping members 30 in a direction perpendicular to the axial direction X in conjunction with the reciprocating movement of the drive shaft 50 along the axial direction X. [Operation of this embodiment] The operation of this embodiment will be described.

[0068] When an external driving source applies a load to the rotating part 72 in contact with the driving source, which load causes movement in the axial direction X, a load in a direction perpendicular to the axial direction X is also applied to the rotating part 72. The roller member 70 transmits the load in the axial direction X to the drive shaft 50 via the rotating part 72 and the support part 71, but does not transmit the load in the direction perpendicular to the axial direction X to the drive shaft 50 by rotating the rotating part 72.

[0069] [Effects of this embodiment] The effects of this embodiment will be described. (1) In the gripping device 100, the frictional force between the cam C and the roller member 70 is generated between the rotating portion 72 and the cam C. The roller member 70 can absorb this frictional force by rotating the rotating portion 72. Furthermore, the load in the axial direction X applied from the cam C is transmitted to the drive shaft 50 via the rotating portion 72, the rotation shaft 70a, and the support portion 71. In other words, the gripping device 100 can transmit the load in the axial direction X to the drive shaft 50 while absorbing the load in the direction perpendicular to the axial direction X caused by the cam C using the rotating portion 72 of the roller member 70. As a result, the roller member 70 can reduce the load in the direction perpendicular to the axial direction X transmitted from the drive source to the drive shaft 50 compared to, for example, a case in which power is transmitted directly from the cam C to the drive shaft 50. Therefore, it is possible to suppress the load from being applied to the pair of levers 40 and the pair of gripping members 30 due to the load in the direction perpendicular to the axial direction X transmitted to the drive shaft 50. As a result, the gripping device 100 can have a longer life.

[0070] (2) The rotation direction of the rotating part 72 of the roller member 70 can be adjusted by adjusting the orientation of the second rod member 52 of the holding member 60. As a result, the gripping device 100 can change the rotation direction of the rotating part 72 to match the rotation direction of the cam C at the installation location of the gripping device 100, while fixing the direction in which the pair of gripping members 30 open and close.

[0071] (3) The holding member 60 rotatably holds the flange portion 55 in the holding chamber 62a, thereby connecting the second rod member 52 to the first rod member 51 so that the second rod member 52 is rotatable relative to the first rod member 51. By holding the second rod member 52 with the holding member 60 so that the second rod member 52 is rotatable relative to the first rod member 51, the gripping device 100 prevents the rotational torque applied to the driving end 50b from being transmitted to the pair of levers 40. As a result, the gripping device 100 can reduce the unbalanced load applied to the pair of levers 40 from an external driving source.

[0072] (4) When a rotational torque about the central axis L extending in the axial direction X is applied to the second rod member 52, the second rod member 52 transmits the rotational torque to the bearing 90 and the rotation restricting member 80 via the pair of engaging flat surfaces 56b and the pair of opposed engaged flat surfaces 91a. In other words, the rotation of the drive shaft 50 caused by the rotational torque is restricted by the rotation restricting member 80 and the bearing 90. As a result, the gripping device 100 restricts the rotation of the drive shaft 50 using the rotation restricting member 80 and the bearing 90, thereby preventing the rotational torque applied to the drive shaft 50 from being transmitted to the pair of levers 40. Furthermore, the second rod member 52 moves in the axial direction X while sliding on the inner surface of the bearing 90 due to a load from an external drive source. In other words, the gripping device 100 can reduce the load applied to the pair of levers 40 from the external drive source while improving the operability of the drive shaft 50 in the axial direction X.

[0073] (5) The gripping device 100 can change the rotation direction of the rotating part 72 by rotating the second rod member 52 relative to the holding member 60. That is, the gripping device 100 can easily change the rotation direction of the rotating part 72 compared to, for example, a case in which the drive shaft 50 is formed integrally with the first rod member 51 and the second rod member 52. Furthermore, because the bearing 90 is provided outside the housing 10, the direction of the pair of engaged flat surfaces 91a can also be easily changed without, for example, performing work such as removing it from the inside of the housing 10. As described above, the gripping device 100 can easily change the rotation direction of the rotating part 72.

[0074] (6) In the gripping device 100, the drive shaft 50 is biased by the elastic member 16 in a direction from the first housing end face 11 to the second housing end face 12. In other words, the direction of the external force required to drive the gripping device 100 is only the direction from the second housing end face 12 to the first housing end face 11 in the axial direction X. For example, a gripping device 100 without the elastic member 16 may be equipped with a linear actuator that moves the drive shaft 50 from the first housing end face 11 to the second housing end face 12. Compared to this case, the gripping device 100 can have a simpler configuration by including the elastic member 16.

[0075] [Example of change] The above embodiment can be modified as follows: The above embodiment and the following modifications can be combined with each other within the scope of technical compatibility.

[0076] The second rod member 52 does not have to have a pair of engaging flat surfaces 56b on the outer peripheral surface of the rod portion 56. For example, the rod portion 56 may have the engaging flat surfaces 56b on only a portion of the outer peripheral surface. In this case, the bearing 90 has the engaged flat surface 91a on the bearing hole defining surface 91 only in a portion that faces the engaging flat surfaces 56b.

[0077] The cross-sectional shape of the rod portion 56 does not have to be a two-face shape. For example, the cross-sectional shape of the rod portion 56 may be a polygon, and the bearing hole-defining surface 91 of the bearing 90 may be shaped to engage with the outer surface of the rod portion 56 having that cross-sectional shape.

[0078] The gripping device 100 does not necessarily have to include the bearing 90. As shown in Fig. 6, in this case, the rod portion 56 is inserted into the restrictive insertion hole 80a, which serves as an insertion hole, and the outer circumferential surface of the rod portion 56 faces the hole-defining surface 84. In this case, the engaged flat surface 91a is formed as part of the hole-defining surface 84. In other words, the hole-defining surface 84 has the engaged flat surface 91a that faces the engaging flat surface 56b.

[0079] The holding member 60 does not have to hold the second rod member 52 rotatably about the central axis L. For example, the flange portion 55 may be fixed to the holding member 60.

[0080] The drive shaft 50 does not need to include the retaining member 60. For example, the first rod member 51 and the second rod member 52 may be directly coupled to each other by forming a female thread on the fixed end 50c and a male thread on the connecting end 50d.

[0081] The drive shaft 50 does not have to be formed by the first rod member 51, the second rod member 52, and the holding member 60. For example, the drive shaft 50 may be formed by molding a single cylindrical member.

[0082] The roller member 70 does not have to include the rotating shaft 70a. For example, the roller member 70 may have the rotating portion 72 as a rolling bearing including an inner ring, an outer ring, and rolling elements interposed between the inner ring and the outer ring, with the inner ring fixed to a pair of support side walls 74. In this case, a load in the axial direction X applied from an external driving source is transmitted to the drive shaft 50 via the outer ring, rolling elements, inner ring, and support portion. Furthermore, a load applied from the external driving source in a direction perpendicular to the axial direction X is absorbed by the rotation of the outer ring relative to the inner ring by the rolling elements.

[0083] The driving source for driving the gripping device 100 is not limited to the motor shaft M and the cam C. For example, as shown in FIG. 7 , the gripping device 100 may be driven by an inclined surface S that moves in a direction perpendicular to the rotation direction of the rotating unit 72 and the axial direction X. In this case, a load in the axial direction X and a load in the moving direction of the inclined surface S are applied to the drive shaft 50 by the inclined surface S via the roller member 70. The gripping device 100 opens and closes the pair of gripping members 30 by moving the drive shaft 50 in the axial direction X due to the load in the axial direction X from the inclined surface S. Furthermore, the gripping device 100 rotates the rotating unit 72 due to the load in the moving direction of the inclined surface S. In other words, even when the gripping device 100 is driven by the moving inclined surface S, the roller member 70 can prevent the load in the direction perpendicular to the axial direction X from being transmitted to the drive shaft 50.

[0084] The gripping device 100 does not have to include the elastic member 16. For example, the gripping device 100 may close the pair of gripping members 30 by using a linear actuator that moves the drive shaft 50 in a direction from the first housing end surface 11 toward the second housing end surface 12.

[0085] [Note] The technical ideas that can be understood from the above-described embodiment and modifications will be described below. (a) a housing defining a through hole extending axially therethrough; a guide member provided at one end of the housing in the axial direction; a pair of gripping members that move along the guide member in a direction perpendicular to the axial direction; a pair of levers connected to the pair of gripping members; a drive shaft that is inserted through the through hole and has a connecting end that connects to the pair of levers and a driving end that protrudes from the other end of the housing; an elastic member that is accommodated in the through hole and biases the drive shaft in a direction from one end toward the other end in the axial direction, a gripping device in which the pair of gripping members open and close in a direction perpendicular to the axial direction in conjunction with movement of the drive shaft in a direction from the other end toward the one end along the axial direction and movement of the drive shaft in a direction from the one end toward the other end due to a biasing force of the elastic member, the drive shaft having a roller member at the drive end; The roller member is A gripping device characterized by having a rotating part that is fixed to the drive end and supported by a support part so that it can rotate around an axis extending in a direction perpendicular to the axial direction. [Explanation of symbols]

[0086] 10...housing, 10a...housing hole as through hole, 20...guide member, 30...pair of gripping members, 40...pair of levers, 50...drive shaft, 50a...connecting end, 50b...driving end, 50c...fixed end, 50d...connecting end, 51...first rod member, 52...second rod member, 55...flange portion, 56b...engaging plane, 60...holding member, 62a...holding chamber, 70...roller member, 71...support portion, 72...rotating portion, 80...rotation restricting member, 80a...regulating insertion hole as insertion hole, 84...hole defining surface, 90...bearing, 90a...bearing hole, 91...bearing hole defining surface, 91a...engaged plane, 100...gripping device, L...central axis as axis, X...axial direction.

Claims

1. a housing defining an axially extending throughbore; a guide member provided at one end of the housing in the axial direction; a pair of gripping members that move along the guide member in a direction perpendicular to the axial direction; a pair of levers connected to the pair of gripping members; a drive shaft that is inserted through the through hole and has a connecting end that connects to the pair of levers and a driving end that protrudes from the other end of the housing, A gripping device in which the pair of gripping members open and close in a direction perpendicular to the axial direction in conjunction with the reciprocating movement of the drive shaft along the axial direction, the drive shaft having a roller member at the drive end; The roller member is A gripping device characterized by having a rotating part that is fixed to the drive end and supported by a support part so that it can rotate around an axis extending in a direction perpendicular to the axial direction.

2. The drive shaft is a first rod member having the connecting end at one end and a fixed end at the other end; a second rod member having the driving end at one end and a connecting end at the other end, The gripping device according to claim 1 , wherein the fixed end and the connecting end are connected by a holding member.

3. the second rod member has a flange portion at a portion near the connection end, The holding member defines a holding chamber that opens in a direction perpendicular to the axial direction, The gripping device described in claim 2, characterized in that the holding member is fixed to the fixed end and holds the flange portion in the holding chamber so that the second rod member can rotate around an axis extending in the axial direction.

4. A rotation restricting member is fixed to the other end of the housing, the second rod member has an engagement plane parallel to the axial direction on at least a portion of an outer surface thereof, and is inserted into an insertion hole defined by the rotation restricting member; the rotation restricting member has a hole defining surface that defines the insertion hole, 4. The gripping device according to claim 2 or 3, wherein the hole-defining surface has an engaged flat surface facing the engaging flat surface.

5. A rotation restricting member having a bearing is fixed to the other end of the housing, the second rod member has an engagement plane parallel to the axial direction on at least a portion of an outer surface thereof, and is inserted into a bearing hole defined by the bearing; The bearing has a bearing hole defining surface that defines the bearing hole, 4. The gripping device according to claim 2, wherein the bearing hole defining surface has an engaged flat surface facing the engaging flat surface.

Images