Stop device for a moving mechanism and a robot

Abstract

A moving mechanism stopping device (1) is equipped with stoppers (2, 3) respectively provided to two members (130, 140) moving relative to each other, restricts the relative movements of the members (130, 140) by impingement of the stoppers (2, 3) upon each other, and has the two members (130, 140) arranged to be spaced away from each other in a direction orthogonal to the direction of the relative movement. At least one of the stoppers (2) comprises: a base (20) which is detachably fixed to the corresponding one member (140); a deformable part (21) which is integrally provided to the base (20) and which is elastically deformed by the impact of impingement; and a deformation restriction part (4, 41a) which is spaced apart from the deformable part (21) in the direction of the relative movement, is fixed to the base (20), and comes into contact with the elastically deformed deformable part (21) so as to limit further elastic deformation thereof.

Description

Technical Field

[0001] The present disclosure relates to a stopping device for a moving mechanism and a robot.

Background Art

[0002] Conventionally, a robot is known that includes a first stopper provided on one of two members that rotate relative to each other about a predetermined axis, and a second stopper provided on the other member (see, for example, Patent Document 1). When the two members are relatively rotated, the first stopper and the second stopper abut against each other, thereby restricting the relative movement range of the two members.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] For stoppers that regulate the movement range of two relatively moving members, the load applied to each member by the collision increases as the two members move away from each other in a direction perpendicular to the moving direction. Therefore, when stoppers that do not plastically deform even due to the generated impact are integrally provided on the two members respectively, the mechanism becomes large in size to ensure strength. On the other hand, a stopper that plastically deforms due to an impact can be made smaller than a stopper that does not plastically deform. However, if the plastic deformation is too large, the relative coasting of the two elements becomes large and the movement range cannot be sufficiently regulated. Therefore, it is desired to effectively regulate the movement range while preventing the mechanism from becoming large in size.

Means for Solving the Problems

[0005] One aspect of the present disclosure is a stopping device for a moving mechanism that includes stoppers provided on each of two relatively moving members and restricts the relative movement of the members by the collision between the stoppers. The two members are arranged apart from each other in a direction orthogonal to the relative movement direction, and at least one of the stoppers includes a base that is detachably fixed to one of the members, a deformation portion that is integrally provided on the base and is plastically deformed by the impact of the collision, and a deformation restricting portion that is fixed to the base at an interval in the relative movement direction with respect to the deformation portion and contacts the plastically deformed deformation portion to restrict the plastic deformation. It is a stopping device for a moving mechanism.

Brief Description of the Drawings

[0006]

Figure 1

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Embodiment for Carrying Out the Invention

[0007] The stop device 1 for a moving mechanism and the robot 100 according to an embodiment of the present disclosure will be described below with reference to the drawings. In the example shown in FIG. 1, the robot 100 according to the present embodiment is a six-axis articulated robot. The robot 100 includes a base 110 fixed to the floor surface and a swivel body 120 rotatable with respect to the base 110 about a vertical first axis J1. Further, the robot 100 includes a first arm 130 rotatable with respect to the swivel body 120 about a horizontal second axis J2, a second arm 140 rotatable with respect to the first arm 130 about a third axis J3 parallel to the second axis J2, and a three-axis wrist unit 150 attached to the tip of the second arm 140.

[0008] The stop device 1 for a moving mechanism according to the present embodiment is provided in one or more of the six rotating joints (joints) of the robot 100. Here, for example, a case where it is provided in a rotating joint that rotationally drives the second arm (one member) 140 with respect to the first arm (the other member) 130 about the third axis (axis) J3 will be exemplified and described.

[0009] As shown in FIG. 2, the stop device 1 for a moving mechanism includes a first stopper (one stopper) 2, a second stopper (the other stopper) 3, and a deformation restricting member (deformation restricting part) 4. The first stopper 2 is detachably attached to the second arm 140. The second stopper 3 is provided on the first arm 130.

[0010] Between the first arm 130 and the second arm 140, a speed reducer 160 is arranged to decelerate the rotation of the shaft of a motor (not shown) and relatively rotate the first arm 130 and the second arm 140. Due to the thickness of the speed reducer 160 in the direction along the third axis J3, the first arm 130 and the second arm 140 are arranged apart in a direction orthogonal to the relative rotation direction (relative movement direction), that is, in the direction along the third axis J3.

[0011] As shown in FIG. 2, the first stopper 2 includes a base 20 fixed to a seating surface 142 formed flush with or parallel to the speed reducer mounting surface 141 of the second arm 140, and a flat plate-shaped protrusion (deformation part) 21 provided on the base 20. As shown in FIG. 3, the base 20 includes a first base 22 detachably fixed to the seating surface 142, and a second base 23 detachably fixed to the first base 22.

[0012] As shown in FIG. 4, the seating surface 142 is provided at a portion where a part of the casting constituting the second arm 140 protrudes radially outward around the third axis J3. The first base 22 is formed in an elongated rectangular strip shape, with the length direction coinciding with the circumferential direction around the third axis J3, the width direction coinciding with the radial direction, and the plate thickness direction coinciding with the third axis J3 direction, and is fixed to the seating surface 142. The second base 23 has the same dimensions as the first base 22 in the length direction and the width direction, and is fixed to the first base 22 in a state where it is overlapped with the first base 22 in the plate thickness direction.

[0013] The protrusion 21 and the second base 23 are integrally formed by cutting a relatively ductile steel material, for example, hot-rolled steel for general structure. The protrusion 21 protrudes in a cantilever shape from the center of the length direction of the second base 23 in the plate thickness direction of the second base 23.

[0014] By fixing the second base 23 to the first base 22 fixed to the seating surface 142 of the second arm 140, as shown in FIG. 2, the protrusion 21 is positioned closer to the first arm 130 in the direction along the third axis J3 by a dimension obtained by adding the plate thickness dimensions of the first base 22 and the second base 23 from the seating surface 142. Since the seating surface 142 protrudes radially outward of the second arm 140, as shown in FIG. 4, the protrusion 21 is also arranged at a position radially outward from the side surface of the speed reducer 160. At this time, the protrusion 21 extends in the direction along the third axis J3 and in the radial direction centered on the third axis J3.

[0015] As shown in FIG. 2, the second stopper 3 is configured by protruding a part of the casting constituting the first arm 130 toward the second arm 140 in the direction along the third axis J3 from the end surface 131 on the speed reducer 160 side. As shown in FIG. 4, the second stopper 3 also protrudes a part of the casting constituting the first arm 130 radially outward, and forms two abutting surfaces 31 extending in the radial direction centered on the third axis J3. In the example shown in the figure, the second stopper 3 is provided at two locations at intervals in the circumferential direction around the third axis J3, and one abutting surface 31 is provided on each second stopper 3.

[0016] Each abutting surface 31 is arranged at a radial position centered on the third axis J3 and a position in the direction of the third axis J3 that overlaps with the protrusion 21 of the first stopper 2 fixed to the second arm 140. Thereby, when the first arm 130 and the second arm 140 rotate relative to each other around the third axis J3, the protrusion 21 and the abutting surface 31 of the second stopper 3 collide at positions exceeding both ends of the relative operating range of the second arm 140 with respect to the first arm 130.

[0017] Since the second stopper 3 is constituted by a part of the casting constituting the first arm 130, it has sufficient strength not to plastically deform even if it collides with the first stopper 2. On the other hand, as shown in FIG. 5, the protrusion 21 of the first stopper 2 that collides with the abutting surface 31 of the second stopper 3 is plastically deformed so as to fall to the side opposite to the second stopper 3 in the circumferential direction around the third axis J3 due to the collision. Since the second base 23 and the protrusion 21 are made of a relatively ductile hot-rolled steel sheet for general structures, the protrusion 21 is plastically deformed in a form that falls from the root without breaking from the second base 23.

[0018] As shown in FIG. 3, the deformation restricting member 4 is constituted by the heads 41a of bolts (first bolts) 41 that are fastened to the screw holes 23a of the second base 23 with a gap between the heads 41a and the protrusion 21 on both sides in the plate thickness direction of the protrusion 21. The first bolt 41 is made of a material having higher rigidity than the hot-rolled steel sheet for general structures that constitutes the second base 23 and the protrusion 21, for example, a chrome molybdenum steel sheet.

[0019] In the present embodiment, the heads 41a of the first bolts 41 that constitute the deformation restricting member 4 are arranged close to both surfaces in the circumferential direction around the third axis J3 of the protrusion 21 and radially inward, that is, at positions closest to the end surface (outer peripheral surface) 131 of the first arm 130 in the radial direction.

[0020] As shown in FIGS. 6 and 7, the first base 22 of the first stopper 2 is fixed to the seating surface 142 by fastening two bolts (second bolts) 42 to the screw holes 142a of the seating surface 142 of the second arm 140. The first base 22 is provided with two counterbores 25 that can completely accommodate the heads 42a of the two second bolts 42, respectively.

[0021] After fixing the first base 22 to the seating surface 142, the second base 23 with the two first bolts 41 fastened to the screw holes 23a is overlapped with the first base 22 in the plate thickness direction, and two bolts (third bolts) 43 are passed through the through holes 23b of the second base 23 and fastened to the screw holes 22a of the first base 22 to fix the second base 23 to the first base 22.

[0022] As shown in FIG. 8, the second bolt 42 is disposed on the axial extension of the first bolt 41. Here, the axial extension includes not only the case where the axis of the first bolt 41 and the axis of the second bolt 42 completely coincide but also the case where there is a slight offset.

[0023] The attachment of the first bolt 41 to the second base 23 may be performed before or after attaching the second base 23 to the first base 22. That is, the first bolt 41 does not contribute to the attachment of the second base 23 to the first base 22.

[0024] Further, as shown in FIG. 8, by fastening two bolts (third bolts) 44 to the screw holes 142b of the seating surface 142 through the through holes 22b and 23c provided in the first base 22 and the second base 23 which are stacked in the plate thickness direction, the first base 22 and the second base 23 are fixed to the seating surface 142 by co-fastening. Thereby, the attachment of the first stopper 2 to the seating surface 142 of the second arm 140 is completed.

[0025] The first base 22 is fixed to the seating surface 142 of the second arm 140 by a total of four bolts, two second bolts 42 and two third bolts 44. The second base 23 is fixed to the first base 22 by four third bolts 43 and 44. Therefore, it is possible to bring the surfaces between the first base 22 and the seating surface 142 and between the first base 22 and the second base 23 into close contact with an equal surface pressure and generate sufficient frictional force so as not to shift significantly even by a collision.

[0026] The operation of the stopping device 1 for a moving mechanism and the robot 100 according to the present embodiment configured as described above will be described below. According to the stopping device 1 for a moving mechanism according to the present embodiment, when the first stopper 2 and the second stopper 3 collide, the energy of the collision is consumed by the plastic deformation generated in the protrusion at the time of the collision, and the relative rotation between the first arm 130 and the second arm 140 is stopped.

[0027] That is, since the first stopper 2 is configured to plastically deform the protrusion 21, it has the advantage of being able to be more compactly configured compared to those that do not plastically deform. Further, when the protrusion 21 plastically deforms due to a collision, the protrusion 21 approaches the head 41a of the first bolt 41 that is arranged at intervals in the circumferential direction around the third axis J3, which is the direction of plastic deformation. When further deformed, the interval disappears and the protrusion 21 contacts the head 41a of the first bolt 41.

[0028] Thereby, further plastic deformation of the protrusion 21 can be restricted by the first bolt 41. The first bolt 41 that restricts the plastic deformation of the protrusion 21 is made of a material having a higher rigidity than the material of the protrusion 21, so it can reliably receive and restrict the plastic deformation of the protrusion 21, and can more reliably stop the coasting of the relative rotation between the first arm 130 and the second arm 140.

[0029] In this case, at the initial stage when the protrusion 21 starts to plastically deform after the collision, the head 41a of the first bolt 41 is arranged at intervals in the circumferential direction around the third axis J3 with respect to the side surface of the protrusion 21, so the plastic deformation of the protrusion 21 is not inhibited by the head 41a of the first bolt 41. Therefore, the protrusion 21 can plastically deform so as to curve from the root portion connected to the second base 23, and can sufficiently consume the energy of the impact.

[0030] An R surface is provided at the root of the protrusion 21, which can prevent breakage due to excessive stress concentration during a collision. Then, after the energy of the collision is sufficiently consumed by the plastic deformation of the protrusion 21, by pressing the protrusion 21 against the head 41a of the first bolt 41 having a high rigidity, further plastic deformation can be effectively restricted.

[0031] If the head 41a of the first bolt 41 is initially brought into contact with the side surface of the protrusion 21, or if a stepped portion integral with the protrusion 21 is provided instead of the head 41a of the first bolt 41, the base of the deformation of the protrusion 21 becomes the head 41a of the first bolt 41 or the end surface of the stepped portion. In these cases, since the base of the deformation of the protrusion 21 approaches the second stopper 3 too much in the direction along the third axis J3, there is a risk of shear fracture. On the other hand, as in the present embodiment, by providing a gap between the head 41a of the first bolt 41 and the side surface of the protrusion 21, the base of the deformation of the protrusion 21 can be separated to the surface of the second base 23, and the protrusion 21 can be plastically deformed without being sheared.

[0032] Further, in the present embodiment, since the first stopper 2 that plastically deforms is detachably attached to the second arm 140, the second stopper 3 can be made not to plastically deform and can be integrally formed with the casting constituting the first arm 130. That is, the second stopper 3 can be configured in a simple shape that only projects a part of the casting constituting the first arm 130 radially outward about the third axis J3.

[0033] Also, since the second stopper 3 has a structure that projects radially outward, the protrusion 21 of the first stopper 2 that the second stopper 3 has collided with is typically plastically deformed such that the radially inner side about the third axis J3 is twisted more greatly than the radially outer side, as shown in FIG. 9. On the other hand, by arranging the head 41a of the first bolt 41 radially inward about the third axis J3, the head 41a of the first bolt 41 can be brought into contact with the portion where the protrusion 21 plastically deforms greatly to limit the plastic deformation.

[0034] In addition, the first stopper 2 in which the protrusion 21 has undergone plastic deformation allows the base 20 to be removed from the second arm 140 and replaced. In this case, the first bolt 41 in contact with the plastically deformed protrusion 21 is difficult to remove by the protrusion 21. However, since the first bolt 41 is not involved in attaching the second base 23 to the first base 22, the second base 23 can be easily removed from the first base 22 by removing the four third bolts 43, 44.

[0035] Also, after removing the second base 23 from the first base 22, the second bolt 42 can be removed, and the first base 22 can be easily removed from the seating surface 142. The first base 22 is considered to be less damaged compared to the second base 23 and can be reused.

[0036] In addition, in the present embodiment, the stopper that undergoes plastic deformation due to a collision is only the first stopper 2. As a result, only the first stopper 2 needs to be replaced after a collision, and the second stopper 3 can be reduced in size and cost with a simple structure integrally formed with the first arm 130.

[0037] In addition, in the present embodiment, the base 20 is separated into a first base 22 and a second base 23 and fastened to each other by bolts 43, 44. As a result, the energy of the collision is consumed by plastically deforming the protrusion 21 and also by the friction between the contact surfaces of the first base 22 and the second base 23. As a result, the relative rotation between the first arm 130 and the second arm 140 can be more effectively stopped.

[0038] Also, when the first stopper 2 is detachably fixed to the second arm 140, the number of bolts for fixing needs to be sufficient to withstand the impact of a collision. However, if the first bolt 41 that does not contribute to the fixing is arranged, the installation space for the fixing bolts will be taken up. In the present embodiment, the base 20 is divided into a first base 22 and a second base 23, and a second bolt 42 for fixing the first base 22 to the seating surface 142 is arranged on the extension in the axial direction of the first bolt 41. Thereby, while preventing the enlargement of the first stopper 2 and the enlargement of the seating surface 142, the necessary number for detachably fixing the first stopper 2 to the second arm 140, for example, the installation space for two second arms and two third bolts 44 can be secured.

[0039] Further, in the present embodiment, the two third bolts 43 are fastened to the screw holes 22a of the first base 22 at the position farthest from the third axis J3 in the radial direction. Thereby, as shown in FIG. 10, it is not necessary to provide the screw holes 22a for fastening these third bolts 43 in the seating surface 142, and accordingly, the radial protrusion amount of the seating surface 142 can be reduced. That is, the enlargement of the casting constituting the second arm 140 can be prevented, and the cost can be reduced. When the enlargement in the radial direction or the circumferential direction of the seating surface 142 is allowed, the screw holes 22a for fastening the third bolts 43 may be provided in the seating surface 142, and the first base 22 and the second base 23 may be fastened together by the second bolt 42 and the two third bolts 43, 44.

[0040] Also, in the present embodiment, the first bolts 41 are fixed to the second base 23 on both sides in the plate thickness direction of the protrusion 21. Thereby, plastic deformation of the protrusion 21 can be restricted by the first bolts 41 regardless of which surface in the plate thickness direction of the cantilever-like protrusion 21 the second stopper 3 collides with. That is, the first stopper 2 can be used as a stopper at both ends of the relative rotation range between the first arm 130 and the second arm 140.

[0041] In the present embodiment, the first stopper 2 that plastically deforms is provided on the second arm 140, and the second stopper 3 that does not plastically deform is provided on the first arm 130, but the reverse may also be true. Further, both the first stopper 2 and the second stopper 3 may be configured to plastically deform.

[0042] In the present embodiment, the contact surface between the first base 22 and the second base 23 is configured by a flat surface. However, restricting means (not shown) for restricting relative movement around the third axis J3, that is, movement in the relative movement direction of the second base 23 with respect to the first base 22, such as unevenness that fits with each other or a key and a key groove, may be provided. By the restricting means, the friction between the contact surfaces of the first base 22 and the second base 23 can be increased, the energy consumption of the collision can be increased, and the displacement between the first base 22 and the second base 23 during the collision can be reduced.

[0043] In the present embodiment, the base 20 of the first stopper 2 is divided into the first base 22 and the second base 23 and fastened by bolts 43 and 44. Instead of this, as shown in FIG. 11, the base 20 and the protrusion 21 may be integrally formed. In this case, in order to secure the necessary number of bolts 45 and 46, it is necessary to expand the base 20 and the seating surface 142 in the radial direction or the circumferential direction centered on the third axis J3. However, the same effect is achieved in that the plastically deforming protrusion 21 is restricted by the head (deformation restricting portion) 45a of the highly rigid bolt 45.

[0044] In the present embodiment, the stop device for the rotary joint of the robot 100 is illustrated. Instead of this, it may be applied to a stop device between two members that are relatively linearly moved in a moving mechanism such as a linear motion mechanism.

Explanation of Reference Numerals

[0045] 1 Stop device for moving mechanism 2 First stopper (one of the stoppers) 3 Second stopper (the other stopper) 4 Deformation restricting member (deformation restricting portion) 20 Base 21 Protrusion (Deformation part) 22 First base 23 Second base 23a Screw hole 41 Bolt (First bolt) 41a Head (Deformation limiting part) 42 Bolt (Second bolt) 43, 44 Bolts (Third bolt) 45a Head (Deformation limiting part) 100 Robot 130 First arm (Other member) 131 End face (Outer peripheral surface) 140 Second arm (One member) 142 Seating surface J3 Third axis line (Axis line)

Claims

1. A stopping device for a moving mechanism, comprising stoppers provided on each of two relatively moving members, and restricting the relative movement of the members by the collision between the stoppers, wherein the two members are arranged apart in a direction orthogonal to the relative movement direction, at least one of the stoppers includes a base detachably fixed to one of the members, a deformation part integrally provided on the base and plastically deformed by the impact of the collision, and a deformation restricting part fixed to the base with a space in the relative movement direction with respect to the deformation part and contacting the plastically deformed deformation part to restrict the plastic deformation, and the base includes a first base detachably fixed to the member, and a second base detachably fixed to the first base and integrally provided with the deformation part, the stopping device for a moving mechanism.

2. The stopping device for a moving mechanism according to claim 1, wherein the other stopper is integrally provided on the other member and is not plastically deformed by the impact of the collision.

3. The stopping device for a moving mechanism according to claim 1, wherein a restricting means for restricting the movement of the second base in the relative movement direction with respect to the first base is provided between the first base and the second base.

4. The stopping device for a moving mechanism according to any one of claims 1 to 3, wherein the deformation restricting part is made of a material having higher rigidity than the deformation part.

5. The stopping device for a moving mechanism according to claim 4, wherein the deformation restricting part is the head of a first bolt fastened to a threaded hole formed in the base.

6. The stopping device for a moving mechanism according to claim 1, wherein the deformation restricting part is the head of a first bolt fastened only to a threaded hole formed in the second base.

7. The stopping device for a moving mechanism includes a second bolt for detachably fixing the first base to the member, and a third bolt for detachably fixing the second base to the first base or the member, and at least one of the second bolts is arranged on an extension in the axial direction of the first bolt, the stopping device for a moving mechanism according to claim 6.

8. The stopping device for a moving mechanism according to claim 7, wherein the deformation part is formed in a flat plate shape extending in the radial direction, and the first bolts are arranged on both sides in the plate thickness direction of the deformation part.

9. The stopping device for a moving mechanism according to claim 8, wherein the first bolt is arranged at a position closest to the outer peripheral surface of the other member in the radial direction. A stopping device for a moving mechanism, comprising stoppers provided on each of two relatively moving members, and restricting the relative movement of the members by the collision of the stoppers with each other, wherein the two members are arranged apart from each other in a direction orthogonal to the relative movement direction, wherein at least one of the stoppers includes a base detachably fixed to one of the members, a deformation portion integrally provided on the base and plastically deformed by the impact of the collision, and a deformation restricting portion fixed to the base with a space therebetween in the relative movement direction with respect to the deformation portion and contacting the plastically deformed deformation portion to restrict the plastic deformation, wherein the two members are supported so as to be relatively rotatable about a predetermined axis, wherein the base is fixed to a seating surface extending orthogonally to the axis radially outward of the outer peripheral surface of the other member, and wherein the deformation portion is arranged radially outward of the outer peripheral surface and extends in a cantilever shape parallel to the axis from the base, the stopping device for a moving mechanism.

11. comprising a plurality of joints, a robot, wherein a stopping device for a moving mechanism according to any one of Claims 1 to 10 is provided on two members constituting at least one of the joints.

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