Stopping devices for mobile mechanisms and robots

Abstract

A stopping device for a moving mechanism includes baffles respectively disposed on two relatively moving components, the relative movement of the components being restricted by the collision of the baffles with each other; the two components are separately disposed in a direction orthogonal to the relative movement direction; at least one baffle includes: a base, a component detachably fixed to one side; a deformable portion integrally disposed on the base, which plastically deforms due to the impact of the collision; and a deformation limiting portion fixed to the base at a distance relative to the deformable portion in the relative movement direction, which contacts the plastically deformed deformable portion to limit the plastic deformation.

Description

Technical Field

[0001] This disclosure relates to stopping devices for mobile mechanisms and robots. Prior Technology

[0002] A robot is known to have a first baffle on one side of the component and a second baffle on the other side of the component between two components that rotate relative to each other around a preset axis. (For a reference example, see Patent Document 1). When the two components rotate relative to each other, the relative movement range of the two components is restricted due to the collision between the first baffle and the second baffle. (Existing technical literature) (Patent Documents)

[0003] Patent Document 1: Japanese Patent Application Publication No. 2019-098463 Summary of the Invention

[0004] (The problem that this invention aims to solve)

[0005] A baffle that restricts the movement range of two relatively moving parts increases the load on each part due to collision as the two parts move further away from the direction orthogonal to the direction of movement. Therefore, in the case of installing one baffle that does not plastically deform even in the event of an impact on each of the two parts, the mechanism becomes larger in order to ensure strength. On the other hand, a baffle that plastically deforms upon impact can be smaller than a baffle that does not plastically deform, but when the plastic deformation is too large, the relative inertia of the two parts is too large and cannot adequately restrict the movement range. Therefore, it is desirable to prevent the organization from becoming too large while effectively limiting its range of movement. (Methods for solving the problem)

[0006] One embodiment of this disclosure is a stopping device for a moving mechanism, comprising baffles respectively disposed on two relatively moving components, wherein the relative movement of the components is restricted by the collision of the baffles with each other; the two components are separately disposed in a direction orthogonal to the relative movement direction; at least one baffle includes: a base, a component detachably fixed to one side; a deformable portion integrally disposed on the base, which plastically deforms due to the impact of the collision; and a deformation limiting portion fixed to the base at a distance relative to the deformable portion in the relative movement direction, which contacts the plastically deformed deformable portion to limit the plastic deformation. Simple Explanation of the Diagram

[0007] [Figure 1] is a schematic overall configuration diagram of a robot according to an embodiment of the present disclosure. [Figure 2] is a front view of the rotary joint between the first and second robotic arms of the robot in Figure 1. [Figure 3] is a perspective view of the first baffle of a stopping device for a moving mechanism according to an embodiment of the present disclosure. [Figure 4] is a schematic diagram showing the rotary joint of the moving mechanism of Figure 3 as viewed from the direction along the third axis. [Figure 5] is a front view showing the state in which the first baffle of the moving mechanism of Figure 3 is plastically deformed due to its collision with the second baffle. [Figure 6] is an exploded perspective view illustrating the structure of the first baffle in Figure 3. [Figure 7] is an exploded perspective view showing the first base of the first baffle in Figure 6 fixed to a plane. [Figure 8] is a cross-sectional view of the first baffle in Figure 3 as shown in Figure 4 (AA). [Figure 9] is a more detailed representation of the plastic deformation of the protrusion of the first baffle in Figure 5, viewed from the direction along the third axis. [Figure 10] shows the relationship between the first baffle in Figure 3 and the plane on which the first baffle is installed, viewed from the direction along the third axis. [Figure 11] is a front view showing a modified example of the first baffle in Figure 3. Implementation

[0008] The following describes a stopping device 1 for a moving mechanism and a robot 100 according to an embodiment of the present disclosure with reference to the drawings. The robot 100 in this embodiment, as shown in Figure 1, is a six-axis multi-joint robot. The robot 100 includes a base 110 fixed to a plane and a rotating torso 120 that can rotate relative to the base 110 about a vertical first axis J1. The robot 100 further includes a first robotic arm 130 that can rotate relative to the rotating torso 120 about a horizontal second axis J2, a second robotic arm 140 that can rotate relative to the first robotic arm 130 about a third axis J3 parallel to the second axis J2, and a three-axis wrist element 150 mounted on the front end of the second robotic arm 140.

[0009] In this embodiment, a stopping device 1 for a moving mechanism is provided in one or more of the six rotary joints (joints) of the robot 100. Here, an example is given of a rotary joint in which the second robotic arm 140 (one side component) is driven to rotate about a third axis J3 (axis) relative to the first robotic arm 130 (the other side component).

[0010] The stopping device 1 for the moving mechanism, as shown in Figure 2, includes a first baffle 2 (one side baffle), a second baffle 3 (the other side baffle), and a deformation limiting component 4 (deformation limiting part). The first baffle 2 is detachably mounted to the second robotic arm 140. The second baffle 3 is provided on the first robotic arm 130.

[0011] A speed reducer 160 is disposed between the first robotic arm 130 and the second robotic arm 140 to slow down the rotation of the shaft of a motor (not shown) and to cause the first robotic arm 130 and the second robotic arm 140 to rotate relative to each other. Based on the thickness along the third axis J3 of the speed reducer 160, the first robotic arm 130 and the second robotic arm 140 are configured to be offset from each other along a direction orthogonal to the relative rotation direction (relative movement direction), that is, along the direction of the third axis J3.

[0012] As shown in Figure 2, the first baffle 2 includes a base 20 and a protrusion (deformable part) 21. The base 20 is fixed to a plane 142 which is formed to be coplanar or parallel to the speed reducer mounting surface 141 of the second robotic arm 140, and the protrusion 21 is provided on the base 20 and is flat. As shown in Figure 3, the base 20 includes a first base 22 detachably fixed to the plane 142 and a second base 23 detachably fixed to the first base 22.

[0013] As shown in Figure 4, plane 142 is provided on a portion of the casting constituting the second robotic arm 140, protruding radially outward with the third axis J3 as the center. As shown in Figure 3, the first base 22 is formed as an elongated rectangular strip plate, with its length direction aligned with the circumferential direction with the third axis J3 as the axis, its width direction aligned with the radial direction, and its thickness direction aligned with the third axis J3, and is fixed to plane 142. The second base 23 has the same dimensions as the first base 22 in both the length and width directions, and is fixed to the first base 22 in a state of overlapping with the first base 22 in the thickness direction.

[0014] The protrusion 21 and the second base 23 are integrally formed by machining relatively ductile steel, such as general structural rolled steel. The protrusion 21 protrudes in a cantilever beam shape from the center of the length direction of the second base 23 toward the thickness direction of the second base 23.

[0015] As shown in FIG2, the protrusion 21, having the sum of the thicknesses of the first base 22 and the second base 23, is positioned close to the first robot arm 130 along the direction of the third axis J3 from the plane 142. Since the plane 142 protrudes radially outward from the second robot arm 140, as shown in FIG4, the protrusion 21 is also positioned radially outward from the side of the reducer 160. In this configuration, the protrusion 21 extends along the direction of the third axis J3 and radially centered on the third axis J3.

[0016] As shown in Figure 2, the second baffle 3 is formed by protruding a portion of the casting constituting the first robotic arm 130 further along the third axis J3 towards the second robotic arm 140 than the end face 131 on the reducer 160 side. As shown in Figure 4, the second baffle 3 also protrudes a portion of the casting constituting the first robotic arm 130 radially outward to form two collision surfaces 31 extending radially about the third axis J3. In the example shown, the second baffle 3 is provided at two locations with a circumferential interval around the third axis J3, and each second baffle 3 has a collision surface 31.

[0017] Each collision surface 31 is positioned radially and along the direction of the third axis J3, overlapping with the protrusion 21 of the first baffle 2 fixed to the second robotic arm 140. Thus, when the first robotic arm 130 and the second robotic arm 140 rotate relative to each other around the third axis J3, the protrusion 21 collides with the collision surface 31 of the second baffle 3 at positions exceeding the ends of the relative range of motion of the second robotic arm 140 with respect to the first robotic arm 130.

[0018] The second baffle 3 is made of part of the casting that constitutes the first robotic arm 130, and therefore has sufficient strength to prevent plastic deformation due to collision with the first baffle 2. On the other hand, the protrusion 21, which collides with the collision surface 31 of the first baffle 2 and the second baffle 3, as shown in Figure 5, undergoes plastic deformation due to the collision, falling towards the other side of the second baffle 3 circumferentially around the third axis J3. Since the second base 23 and the protrusion 21 are made of general-purpose rolled steel with relatively high ductility, the plastic deformation of the protrusion 21 is such that it falls from the root and does not break from the second base 23.

[0019] As shown in Figure 3, the deformation limiting component 4 is composed of the bolt head 41a of the first bolt 41 (bolt) which is locked into the screw hole 23a of the second base 23 on both sides of the protrusion 21 in the thickness direction, with a gap between it and the protrusion 21. The first bolt 41 is made of a material with higher rigidity than the rolled steel used in the general construction of the second base 23 and the protrusion 21, such as chromium-molybdenum steel.

[0020] In this embodiment, the bolt head 41a of the first bolt 41 constituting the deformation limiting component 4 is close to the protrusion 21 on both sides of the circumference around the third axis J3 and is arranged on the radially inner side, that is, at the position that is radially closest to the end face 131 (outer circumferential surface) of the first robotic arm 130.

[0021] As shown in Figures 6 and 7, the first base 22 of the first baffle 2 is fixed to the plane 142 by locking two second bolts 42 (bolts) into the screw holes 142a of the plane 142 of the second robotic arm 140. The first base 22 is provided with two countersunk holes 25, which can completely accommodate the bolt heads 42a of the two second bolts 42 respectively.

[0022] After fixing the first base 22 to the plane 142, the second base 23, which is locked with two first bolts 41 in the screw hole 23a, is overlapped with the first base 22 along the thickness direction. The second base 23 is fixed to the first base 22 by passing two third bolts 43 (bolts) through the through hole 23b of the second base 23 and locking them in the screw hole 22a of the first base 22.

[0023] As shown in Figure 8, the second bolt 42 is positioned at the axial extension of the first bolt 41. Here, the axial extension includes not only cases where the axis of the first bolt 41 and the axis of the second bolt 42 are completely aligned, but also cases where there is a slight offset.

[0024] The installation of the first bolt 41 onto the second base 23 can be performed before or after the second base 23 is installed onto the first base 22. In other words, the installation of the first bolt 41 onto the first base 22 is unrelated to the installation of the second base 23 onto the first base 22.

[0025] As shown in Figure 8, by locking two third bolts 44 (bolts) passing through the through holes 22b and 23c of the first base 22 and the second base 23 that overlap along the thickness direction into the screw hole 142b of the plane 142, the first base 22 and the second base 23 are fastened and fixed together to the plane 142. This completes the installation of the first baffle 2 on the plane 142 of the second robotic arm 140.

[0026] The first base 22 is fixed to the plane 142 of the second robotic arm 140 by 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, the first base 22 and the plane 142, as well as the first base 22 and the second base 23, are in close contact with each other with equal surface pressure, which can generate sufficient friction and prevent significant misalignment due to collision.

[0027] The following explains the function of the stopping device 1 for the moving mechanism and the robot 100 of this embodiment. The moving mechanism stopping device 1 and the robot 100 of this embodiment stop the relative rotation of the first robotic arm 130 and the second robotic arm 140 when the first baffle 2 collides with the second baffle 3 by consuming the energy of the collision through plastic deformation that occurs on the protrusion during the collision.

[0028] In other words, since the protrusion 21, which is plastically deformable, is used as the first baffle 2, it has the advantage of being able to be closely configured compared to the non-plastically deformable one. When the protrusion 21 is plastically deformed due to collision, the protrusion 21 is close to the bolt head 41a of the first bolt 41, which is circumferentially spaced around the third axis J3 in the direction of plastic deformation. When it is further deformed, the gaps disappear, and the protrusion 21 comes into contact with the bolt head 41a of the first bolt 41.

[0029] Therefore, the first bolt 41 can be used to limit further plastic deformation of the protrusion 21. The first bolt 41, which limits the plastic deformation of the protrusion 21, is made of a material with higher rigidity than the material of the protrusion 21, so it can reliably prevent and limit the plastic deformation of the protrusion 21, and more reliably stop the coasting of relative rotation between the first robotic arm 130 and the second robotic arm 140.

[0030] In this situation, during the initial stage of plastic deformation of the protrusion 21 after the collision, since the bolt heads 41a of the first bolt 41 are spaced apart from the sides of the protrusion 21 in the circumferential direction around the third axis J3, the plastic deformation of the protrusion 21 is not hindered by the bolt heads 41a of the first bolt 41. Therefore, the protrusion 21 can bend from its root connected to the second base 23, which can sufficiently dissipate the energy of the collision.

[0031] An R-face is provided at the root of the protrusion 21 to prevent breakage due to excessive stress concentration during collision. Furthermore, after the collision energy is completely consumed by the plastic deformation of the protrusion 21, the plastic deformation above it can be effectively limited because the protrusion 21 abuts against the bolt head 41a of the high-rigidity first bolt 41.

[0032] Assuming that the bolt head 41a of the first bolt 41 is in contact with the side of the protrusion 21 from the beginning, or that a segment integral with the protrusion 21 is provided instead of the bolt head 41a of the first bolt 41, the root of the deformation of the protrusion 21 will be the bolt head 41a of the first bolt 41 or the end face of the segment. In these cases, there is a concern that the root of the deformation of the protrusion 21 may be too close to the second baffle 3 along the direction of the third axis J3, resulting in shear fracture. To address this, by providing a gap between the bolt head 41a of the first bolt 41 and the side of the protrusion 21 as in this embodiment, the root of the deformation of the protrusion 21 can be moved away from the second baffle 3 and up to the surface of the second base 23, allowing the protrusion 21 to undergo plastic deformation without shear fracture.

[0033] Furthermore, in this embodiment, since the first baffle 2, which is capable of plastic deformation, is detachably mounted on the second robotic arm 140, the second baffle 3 can be designed to not be plastically deformed, and can be configured to be integrated with the casting constituting the first robotic arm 130. That is to say, the second baffle 3 can be configured with a simple shape that only protrudes a portion of the casting constituting the first robotic arm 130 radially outward about the third axis J3.

[0034] Furthermore, since the second baffle 3 is designed to protrude radially outward, the protrusion 21 of the first baffle 2 that collides with the second baffle 3 generally undergoes greater torsional plastic deformation on the radially inner side with respect to the third axis J3 than on the outer side, as shown in Figure 9. In this regard, by positioning the bolt head 41a of the first bolt 41 radially inside the axis with the third axis J3 as the axis, the portion of the protrusion 21 that deforms significantly can contact the bolt head 41a of the first bolt 41 to limit plastic deformation.

[0035] Furthermore, the first baffle 2, whose protrusion 21 has undergone plastic deformation, can remove the base 20 from the second robotic arm 140 for exchange. In this situation, the bolt head 41a of the first bolt 41, which is in contact with the plastically deformed protrusion 21, is difficult to remove due to the protrusion 21. However, since the first bolt 41 is not related to the installation of the second base 23 on the first base 22, the second base 23 can be easily removed from the first base 22 by removing the four third bolts 43 and 44.

[0036] Furthermore, 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 plane 142. It is expected that the first base 22 will suffer less damage than the second base 23 and can be reused.

[0037] Furthermore, in this embodiment, only the first baffle 2 undergoes plastic deformation due to the collision. Therefore, it is sufficient to replace the first baffle 2 after the collision, and the second baffle 3 is a simple structure integrated with the first robotic arm 130, which reduces the need for large-scale construction and lower costs.

[0038] In this embodiment, the base 20 is separated into a first base 22 and a second base 23, which are locked together by four third bolts 43 and 44. Thus, the energy of the collision is dissipated by the plastic deformation of the protrusion 21, and also by the friction between the contact surfaces of the first base 22 and the second base 23. This results in a more effective cessation of the relative rotation between the first robotic arm 130 and the second robotic arm 140.

[0039] Furthermore, when the first baffle 2 is detachably fixed to the second robotic arm 140, the number of bolts used for fixing is the necessary number to withstand the impact of a collision. However, if the first bolt 41, which is not related to fixing, is configured, the space for fixing bolts is occupied. In this embodiment, the base 20 is divided into a first base 22 and a second base 23, and the second bolt 42, which fixes the first base 22 to the plane 142, is configured at the axial extension of the first bolt 41. This prevents the first baffle 2 and the plane 142 from becoming too large, while ensuring sufficient space for the number of bolts required to detachably fix the first baffle 2 to the second robotic arm 140, such as two second robotic arms and two third bolts 44.

[0040] In this embodiment, the two third bolts 43 are locked with the screw holes 22a of the first base 22 at the positions furthest radially from the third axis J3. As shown in FIG10, it is not necessary to place the screw holes 22a for locking these third bolts 43 on the plane 142, thereby reducing the radial protrusion of the plane 142. That is, it is possible to prevent the casting constituting the second robotic arm 140 from becoming too large, thus reducing costs. However, if radial or circumferential expansion of the plane 142 is permissible, the screw holes 22a for locking the third bolts 43 can also be placed on the plane 142, and the first base 22 and the second base 23 can be fastened together by the second bolt 42 and the two third bolts 43 and 44.

[0041] In this embodiment, the first bolts 41 are fixed to the second base 23 on both sides of the protrusion 21 in the thickness direction. Therefore, the first bolts 41 can limit the plastic deformation of the protrusion 21 when the second baffle 3 collides with any side of the cantilever beam-shaped protrusion 21 in the thickness direction. In other words, the first baffle 2 can be used as a baffle at both ends of the relative rotation range of the first robotic arm 130 and the second robotic arm 140.

[0042] In this embodiment, a first baffle 2 that can plastically deform is provided on the second robotic arm 140, and a second baffle 3 that cannot plastically deform is provided on the first robotic arm 130, but the reverse is also possible. Alternatively, both the first baffle 2 and the second baffle 3 can be plastically deformable.

[0043] In this embodiment, the contact surfaces of the first base 22 and the second base 23 are planar, but restrictive means (not shown in the figure) can also be provided to limit the relative movement around the third axis J3, that is, the movement of the second base 23 relative to the first base 22 in the direction of relative movement. By increasing the friction between the contact surfaces of the first base 22 and the second base 23 through the restrictive means, the misalignment between the first base 22 and the second base 23 during collision can be reduced.

[0044] In this embodiment, the base 20 of the first baffle 2 is divided into a first base 22 and a second base 23, which are secured by bolts 43 and 44. However, as shown in FIG11, the base 20 and the protrusion 21 can also be constructed as a single unit. In this case, in order to ensure the necessary number of bolts 45 and 46, it is necessary to expand the base 20 and the plane 142 radially or circumferentially about the third axis J3. However, the part of the protrusion that is plastically deformed and restricted by the bolt head 45a (deformation limiting part) of the high-rigidity bolt 45 still plays the same role.

[0045] Furthermore, in this embodiment, the stopping device of the rotary joint of the robot 100 is used as an example. Instead, it can also be applied to the stopping device between two parts that move linearly relative to each other in a moving mechanism such as a direct drive mechanism.

[0046] 1: Stopping device for moving mechanism 2: First baffle 20: Base 21: Protrusion 22: First Foundation 22a: Screw hole 22b: Through hole 23: Second base 23a: Screw hole 23b: Through hole 23c: Through hole 25: Countersunk hole 3: Second baffle 31: Collision surface 4: Deformation limiting components 41: First bolt 41a: Bolt head 42: Second bolt 42a: Bolt head 43: Third bolt 44: Third bolt 45: Bolt 45a: Bolt head 46: Bolt 100: Robot 110: Base 120: Rotate the torso 130: The First Robotic Arm 131: End face 140: Second robotic arm 141: Gearbox mounting surface 142: Plane 142a: Screw hole 142b: Screw hole 150: Wrist Components 160: Gearbox J1: First axis J2: Second axis J3: Third Axis

Claims

1. A stopping device for a moving mechanism, comprising baffles respectively disposed on two relatively moving components, wherein the relative movement of the components is restricted by collision between the baffles; the two components are separately disposed in a direction orthogonal to a relative movement direction; at least one of the baffles comprises: A base, detachably fixed to one side of the component; a deformable portion, integrally disposed on the base, plastically deformed by impact; and a deformation limiting portion, fixed to the base at a distance relative to the deformable portion in the relative movement direction, contacting the plastically deformed deformable portion to limit plastic deformation; wherein the base includes: a first base, detachably fixed to the component; and a second base, detachably fixed to the first base and integrally disposed with the deformable portion.

2. A stopping device for a moving mechanism as described in claim 1, wherein, The baffle on the other side is integrally mounted on the component on the other side and will not be plastically deformed due to the impact of a collision.

3. A stopping device for a moving mechanism as described in claim 1, wherein, A limiting means is provided between the first base and the second base to restrict the movement of the second base relative to the first base in the relative movement direction.

4. A stopping device for a moving mechanism as described in any one of claims 1 to 3, wherein, The deformation limiting part is made of a material with higher rigidity than the deformation part.

5. A stopping device for a moving mechanism as described in claim 4, wherein, The deformation limiting part is locked to the head of the first bolt in one of the screw holes formed in the base.

6. A stopping device for a moving mechanism as described in claim 1, wherein, The deformation limiting part is locked to the head of the first bolt in one of the screw holes formed in the second base.

7. The stopping device for the moving mechanism as described in claim 6 further includes: A second bolt is used to detachably secure the first base to the component; And a third bolt for detachably securing the second base to the first base or the component; at least one of the second bolts is disposed on the axial extension of the first bolt.

8. A stopping device for a moving mechanism as described in claim 7, wherein, The deformable portion is formed as a flat plate extending radially, and the first bolt is disposed on both sides of the deformable portion in the thickness direction.

9. A stopping device for a moving mechanism as described in claim 8, wherein, The first bolt is positioned at the point where it is radially closest to an outer circumferential surface of the component on the other side.

10. A stopping device for a moving mechanism, comprising baffles respectively disposed on two relatively moving components, wherein the relative movement of the components is restricted by collision between the baffles; the two components are separately disposed in a direction orthogonal to a relative movement direction; at least one of the baffles comprises: A base, detachably fixed to one side of the component; a deformable portion, integrally provided on the base, plastically deformable due to impact; and a deformation limiting portion, fixed to the base at a distance from the deformable portion in the relative movement direction, contacting the plastically deformed portion to limit plastic deformation; wherein the two components are supported so as to be rotatable relative to each other about a predetermined axis; the base is fixed on a plane extending radially outward from an outer peripheral surface of the other component, orthogonally to the axis; the deformable portion is disposed radially outward from the outer peripheral surface, extending from the base parallel to the axis in a cantilever beam shape.

11. A robot comprising a plurality of joints, and having a stopping device for a movement mechanism as described in any one of claims 1 to 10 between at least one set of two components constituting the joint.

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