JP4397223B2 - Robot joint axis stopper - Google Patents

Description

  The present invention is provided on one of the two links sandwiching the joint axis of the robot and abuts against a fixed portion of the other link to mechanically rotate the two links around the joint axis. It relates to a stopper to be regulated.

  Robots, particularly humanoid robots, have many joint axes, and each joint axis requires a stopper that determines the operating range. The purpose of the original stopper is to allow the joint shaft to move with a predetermined torque until the stopper provided on one of the two links sandwiching the joint shaft for positioning comes into contact with the fixed portion of the other link However, the stopper may hit the fixed part due to an unexpected operation such as an operation outside the control (malfunction) or a setting error (human error). In such a case, it is sufficient that the shaft rotation can be received by the stopper, but if that is not the case, some part of the robot will be damaged.

  However, if the part of the robot that is damaged when an unexpected motion occurs is unspecified, there will be a problem that it takes time to recover and adjust if the part that is troublesome to replace is damaged. It was.

  In addition, when the stopper is screwed and fixed from the side of one link facing the fixed part of the other link, if the part of the stopper protruding from the link breaks, it is screwed into the link. There was a problem that the removed part remained there and became difficult to remove, and it took more time for recovery and adjustment.

An object of the present invention is to advantageously solve the above-mentioned problem, and the joint shaft stopper of the robot according to the present invention is provided on one of the two links sandwiching the joint shaft of the robot, and the other A stopper that abuts against a fixed portion of the link and mechanically restricts relative rotation of the two links around the joint axis, and a base portion that is detachably fixed to the one link, and A contact portion that contacts a fixed portion; and a low-strength portion that is positioned between the base portion and the contact portion and has a predetermined strength lower than those of the base portion and the contact portion. Is a portion located on the tip side of the base portion of the convex portion protruding from the base portion, the low-strength portion is the base portion of the convex portion, and the convex portion is press-fitted into the base portion. Projecting from its base And it is characterized in Oh Rukoto in part you are.

  According to the joint axis stopper of the robot of this invention, the joint axis can be determined until the stopper provided on one of the two links sandwiching the joint axis for positioning comes into contact with the fixed portion of the other link. When moving with torque, the low strength part with a predetermined strength that can withstand that torque will hold without being damaged, and the stopper will serve as a function of restricting relative rotation, while the joint shaft will behave unexpectedly. When raised, the low-strength part is damaged by the bending moment from the contact part that contacts the fixed part of the other link, and the base part is easily removed from the link. Since it can be replaced with a new stopper, restoration and adjustment can be easily performed in a short time.

Further , according to the joint shaft stopper of the robot of the present invention, the abutment portion is a portion located on a distal end side from a base portion of the convex portion protruding from the base portion, and the low-strength portion is the convex portion. Since the stress concentration occurs in the root portion, the low strength portion can be made to have a desired low strength by appropriately setting the degree of the stress concentration.

Then, according to the joint axis stopper of the robot of the present invention, the convex portion of the shaft-like member which is press-fitted to the base, because it is part projecting from its base, base and manufactured separately the axial Since the stopper can be manufactured by press-fitting the member into the base, each manufacturing process can be simplified, and the manufacturing can be made easier and less expensive.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view showing an embodiment of the joint axis stopper of the robot of the present invention applied to the hip joint axis of the humanoid robot, and FIGS. 2A and 2B are views of the humanoid robot. FIG. 3 and FIG. 4 are a front view and a perspective view showing a frame configuration of the humanoid robot, and FIG. 5 is a robot of the present invention applied to an ankle joint axis of the humanoid robot. perspective view showing an example of a stopper of the joint axis, and FIG. 6 (a), (b) , (c), of another reference example of the stopper joint axis of the robot (d) is the present invention It is the top view in the original state shown, a side view, a perspective view, and a perspective view in a damaged state.

  As shown in FIGS. 2 (a) and 2 (b), the humanoid robot has two legs 2 under the body 1, and these legs 2 balance the dynamics in an inverted pendulum by a known method. While walking. This humanoid robot also has arms 3 on the left and right as viewed from the robot itself of the body 1 and a head 4 on the body 1.

  The fuselage 1 here comprises an upper half 1a and a lower half 1b that are connected to each other at the waist so as to be able to rotate back and forth and to the left and right. As shown in FIGS. 3 and 4, the fuselage upper half 1a. The frame includes a fuselage outer shell 5 formed by casting an aluminum alloy, a tower bar 6 attached to the fuselage shell 5 and two pipe frames 7, and is divided into a front and rear split fuselage. The inside of the shell outer shell 5 and the left and right sides of the rear part are spaces for mounting electrical equipment (not shown). The frame 12 of the lower half 1b of the fuselage is formed by casting an aluminum alloy so as to form a substantially inverted T shape when viewed from the front, and is arranged inside the front cover 13 and the bottom cover 14 of the lower half of the fuselage. In addition, the left and right side portions corresponding to the T-shaped arm portion of the frame 12 serve as mounting spaces for two battery units (not shown).

  The hip joint, which is the root of each leg 2 to the lower half 1b of the trunk, rotates the hip joint frame 15 relatively to the left and right around the axis Y with respect to the frame 12, as shown in FIGS. A crotch yaw axis to be moved, a crotch roll axis to rotate the leg support member 16 left and right relative to the hip joint frame 15 about the axis R, and a leg 2 relative to the leg support member 16 about the axis P It has three joint axes with a crotch pitch axis that is rotated back and forth.

  Thus, the joint shaft stopper of the embodiment shown in FIG. 1 and applied to a crotch pitch shaft for rotating the leg 2 back and forth relatively around the axis P with respect to the leg support member 16 is as follows. The leg support member 16 serving as one of the two links sandwiching the crotch pitch axis is in contact with a stopper 20 which is a fixed portion of the leg 2 serving as the other link, and the leg support member 16 and the leg 2 mechanically restricts relative rotation about the axis P and thus the crotch pitch axis, and is fitted in the groove of the leg support member 16 as one link and fixed to the leg support member 16 by a bolt 18 so as to be detachable. A base portion 19, a contact portion that contacts the stopper 20 of the leg 2 as the other link, a tip portion that is a portion located on the tip side from the root portion of the pin 21, and the base portion 19 and the pin 21. Tip And a base portion of the pin 21 as a low strength portion having a predetermined strength lower than those of the base portion 19 and the tip portion of the pin 21, and the pin 21 here is a shaft-like member. One end of the base 19 is press-fitted and fixed in the hole formed in the base 19, and the other end is protruded from the base 19.

  According to the joint shaft stopper 17 of the robot of this embodiment, the tip end portion of the pin 21 of the stopper 17 provided on the leg support member 16 as one of the two links sandwiching the crotch pitch shaft for positioning. When the crotch pitch axis is moved with a predetermined torque until it comes into contact with the stopper 20 of the leg 2 as the other link, the root portion of the pin 21 as a low strength portion having a predetermined strength that can withstand that torque is broken. If the crotch pitch axis causes an unexpected movement, the stopper 17 functions as an original relative rotation restriction by holding it up, but from the tip of the pin 21 that contacts the stopper 20 of the leg 2. The base portion of the pin 21 is damaged by the bending moment, and the base portion 19 is not subjected to excessive force due to the breakage. Therefore, the base portion 19 can be easily removed from the leg support member 16 by loosening the bolt 18. It is possible to replace it with a new stopper 17 is removed, it is possible to easily perform the recovery and adjustment in a short period of time.

  Moreover, according to the joint axis stopper 17 of the robot of this embodiment, the abutment portion is a tip portion that is a portion located on the tip side of the root portion of the portion (protrusion portion) of the pin 21 protruding from the base portion 19. Since the low-strength portion is the root portion of the protruding portion of the pin 21, stress concentration occurs in the root portion. Therefore, the low-strength portion is desired by appropriately setting the degree of stress concentration. Of low strength.

  Furthermore, according to the joint shaft stopper 17 of this embodiment, the convex portion is a portion of the pin 21 that is press-fitted into the base portion 19 and protrudes from the base portion 19, and thus is manufactured separately from the base portion 19. Since the stopper 17 can be manufactured by press-fitting the pin 21 into the base portion 19, the individual manufacturing steps can be simplified, and the manufacturing can be made easier and less expensive.

FIG. 5 shows a reference example of the joint axis stopper of the robot of the present invention applied to the ankle joint axis of the humanoid robot. The ankle joint in this case is relative to the leg 2 with the ankle frame 9 around the axis p. In particular, it has two joint axes: an ankle pitch axis that pivots back and forth, and an ankle roll axis that pivots the foot 10 to the left and right relative to the ankle frame 9 around the axis r.

Then, one of the two stoppers of this reference example indicated by reference numeral 22 in FIG. 5 (the stopper 22 on the right side in FIG. 5) pivots the ankle frame 9 relatively back and forth around the axis p with respect to the leg 2. Applied to the ankle pitch axis to be provided, provided on the ankle frame 9 as one of the two links sandwiching the ankle pitch axis, and in contact with a stopper 24 which is a fixed portion of the leg 2 as the other link The axis p of the ankle frame 9 and the leg 2 and thus the relative rotation around the ankle pitch axis is mechanically restricted, and the side facing the stopper 24 in the screw hole provided in the flange of the ankle frame 9 as one link The base 23 is detachably fixed by being screwed in from the opposite side, and is located on the distal end side from the base portion of the pin 25 as a contact portion that contacts the stopper 24 of the leg 2 as the other link. And the base of the pin 25 as a low strength portion located between the base 23 and the tip of the pin 25 and having a predetermined strength lower than those of the base 23 and the pin 25. The pin 25 is formed integrally with the base 23. The other stopper 22 is applied to the ankle roll shaft.

Similarly to the previous embodiment, the stopper 22 of this reference example can be held without damage to the root portion of the pin 25 under normal conditions. However, when the ankle pitch axis or the ankle roll axis causes an unexpected motion, The base portion of the pin 25 is damaged by the bending moment from the tip portion of the pin 25 abutting against the stopper 20 or the like, and the base portion 23 is not subjected to excessive force by the damage. 9 can be easily removed and replaced with a new stopper 22, so that recovery and adjustment can be easily performed in a short time.

FIG. 6 shows another reference of the joint shaft stopper of the robot according to the present invention, which is suitable for use when the base portion of the stopper is screwed and fixed from the side of one link facing the fixing portion of the other link. In the stopper of this reference example shown by reference numeral 26 in FIG. 6, the base portion 27 screwed into one link and the fixed portion of the other link abut the portion on the tip side from the root portion as a contact portion. The pin 28 is integrally formed, and a transverse groove 28a that engages with the tip of the minus driver when the stopper is screwed is formed on the tip surface of the pin 28, and the root of the pin 28 as a low-strength portion is formed. The part has two transverse (diameter direction) through-holes 29 orthogonal to each other.

According to the stopper 26 of this reference example , as in the previous embodiment, the root portion of the pin 28 is normally held without being damaged, but when the joint shaft causes an unexpected motion, the other link The bending moment from the tip of the pin 28 that contacts the fixed portion breaks the vicinity of the transverse through-hole 29 at the base of the pin 28 due to stress concentration, and the base 27 is not subjected to excessive force due to the breakage. By loosening 27, it can be easily removed from the one link and replaced with a new stopper 26, so that recovery and adjustment can be easily performed in a short time.

Moreover, according to the stopper 26 of this reference example , when the transverse through-hole 29 breaks due to stress concentration, the transverse through-hole 29 is shown in the transverse groove (same reference numeral for convenience) as shown in FIG. 29) and exposed to the side of the one link that faces the fixed part of the other link, so that the base 27 of the stopper 26 can be moved by simply turning the groove with the tip of a normal flat-blade screwdriver. It can be easily removed. Further, the strength of the low-strength portion can be easily changed by changing the inner diameter of the transverse through-hole 29 or increasing / decreasing the number thereof.

  Although the present invention has been described based on the illustrated example, the present invention is not limited to the above example. For example, the joint axis stopper of the robot of the present invention can be applied to a joint axis other than the joint axis of the above example. It can be applied to joint axes of robots other than humanoid robots.

Thus, according to the joint shaft stopper of the robot of the present invention, when the joint shaft causes an unexpected operation, the low-strength portion is damaged by the bending moment from the contact portion that contacts the fixed portion of the other link, Since an excessive force is not exerted on the base due to the breakage, the base can be easily removed from the link and replaced with a new stopper, so that recovery and adjustment can be easily performed in a short time.
The abutting portion is a portion positioned on the tip side from the base portion of the convex portion protruding from the base portion, and the low-strength portion is a root portion of the convex portion, and stress concentration is applied to the base portion. Therefore, the low strength portion can be made to have a desired low strength by appropriately setting the degree of stress concentration.
And since the said convex part is a part which protrudes from the base part of the shaft-shaped member press-fitted in the said base, since a shaft-shaped member manufactured separately from the base can be press-fitted into the base, a stopper can be manufactured. , Individual manufacturing processes can be simplified, making manufacturing easier and less expensive.

It is a perspective view which shows one Example of the stopper for joint axes of the robot of this invention applied to the hip joint axis of a humanoid robot. (A), (b) is the front view and side view which show the whole said humanoid robot. It is a front view which shows the frame structure of the said humanoid robot. It is a perspective view which shows the frame structure of the said humanoid robot. It is a perspective view which shows one reference example of the stopper for joint axes of the robot of this invention applied to the ankle joint axis of the humanoid robot. (A), (b), (c), (d) is a plan view, a side view, a perspective view, and a breakage in an original state showing another reference example of the joint shaft stopper of the robot of the present invention. It is a perspective view in a state.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Body 1a Upper body half 1b Lower body half 2 Leg 3 Arm 4 Head 5 Body shell 6 Tower bar 7 Pipe frame 8 Body upper half cover 9 Ankle frame 10 Feet 12 Body lower half frame 13 Body lower half Front cover 14 Butt cover 15 Hip joint frame 16 Leg support member 17, 22, 26 Joint shaft stopper 18 Bolt 19, 23, 27 Base 20, 24 Stopper 21, 25, 28 Pin P, p Pitch axis R, r Roll axis Y yaw axis

Claims (1)

A stopper provided on one of the two links sandwiching the joint axis of the robot and mechanically restricting the relative rotation of the two links around the joint axis by contacting a fixed portion of the other link ,
A base that is detachably fixed to the one link;
A contact portion that contacts the fixed portion of the other link;
A low-strength portion located between the base portion and the contact portion and having a predetermined strength lower than those of the base portion and the contact portion ,
The contact portion is a portion located on the tip side from the base portion of the convex portion protruding from the base portion,
The low-strength portion is a root portion of the convex portion;
The convex portion is, the shaft-like member which is press-fitted to the base, and wherein the Oh Rukoto in portion projecting from its base, stopper joint axis of the robot.

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