JP4376660B2 - Joint actuator - Google Patents

Description

  The present invention relates to a joint actuator, and more particularly, to an actuator applied to a joint part for bending and driving an upper joint part and a lower joint part in each of two or more legs of a walking robot.

  In recent years, a bipedal walking robot capable of bipedal walking has been realized, and research aimed at improving its walking performance has been conducted. As a walking technique of a biped robot, Non-Patent Document 1 shown below is known as a technique for withstanding an impact at the time of landing of a foot during walking.

Fumio Kanehiro, Kenji Kaneko, Shuji Kajita, Kazuhito Yokoi, Kiyoji Fujiwara, Hirohisa Hirukawa, Toshikazu Kawasaki, Masaru Hirata, Takakatsu Igarashi, “Development of Robot Platform for Human Cooperation and Coexistence Robot System Project”, Japanese Robot Academic Journal, 2003, Vol. 21, No. 2, p. 201-211

  Non-Patent Document 1 states that as a measure for enduring the impact of the foot landing during walking, the biped walking robot is bent even when the knee is standing or walking. As a result, the posture of the biped robot is a so-called hip that keeps its back at any time. Thus, Non-Patent Documents 2 and 3 shown below are known as techniques for improving the walking posture of a biped robot.

Tetsuya Kinugasa, Yoshinori Hashimoto, Hideaki Fushimi, “Passive Walking of Biped Emu with Attitude Control of Body”, Proceedings of 2003 IEEE / RSJ, International Conference on Intelligent Robots and Systems, October 2003, P.346-351 Masafumi Okada, Tatsuya Goto, Yoshihiko Nakamura, “Knee joint mechanism that realizes the reaction force of walking robot”, Proceedings of the 20th Annual Conference of the Robotics Society of Japan, September 2002, 1C19

  However, some actuators used in the joints of biped robots use electromagnetic servo motors. However, electromagnetic servo motors have a small torque for their weight, and are used alone as biped robots. Since the torque required for walking cannot be generated, it is used with an appropriate speed reducer.

  For this reason, the weight of a biped robot with many joints is increased, which causes a reduction in the robot's motion performance. In particular, since the torque of the actuator employed in the knee portion of the biped walking robot is significantly insufficient, a biped walking robot capable of running has not been realized.

  Furthermore, as a study for improving the walking posture, there is a walking method disclosed in Non-Patent Document 2, called a passive walk that interprets walking motion as a motion in which the body continues to fall down. When the foot is not landing, the knee joint needs to be torque free.

  However, in order to realize a torque-free state in the joint part of a biped walking robot using an electromagnetic servomotor as an actuator, a clutch mechanism is separately installed in the joint part as in the technique disclosed in Non-Patent Document 3. Since it must be added, there is a problem that the mechanism of the joint is complicated.

  Here, the main objects to be solved by the present invention are as follows.

  That is, the first object of the present invention is to use an ultrasonic motor for a joint part, thereby exhibiting high torque performance in a low speed range for bending driving of the joint part, and eliminating the need to mount a speed reducer. It is an object of the present invention to provide a joint actuator that can reduce the weight.

  The second object of the present invention is to enable switching so that the pre-pressure applied to the ultrasonic motor is maximized when the foot is landed and minimized when the foot is landed. While a high torque is generated in the part, the joint part is set in a torque-free state when it becomes a free leg, and a joint actuator capable of passive walk by a simple mechanism is provided.

  Other objects of the present invention will become apparent from the specification, drawings, and particularly the description of each claim.

  In the device of the present invention, a driving actuator applied to each joint portion of each leg portion of the walking robot, the piezoelectric vibrator that vibrates the natural vibration when a predetermined alternating voltage is applied to the joint portion. A stator that laminates and excites arbitrary vibration on the circumscribed vibration end face, and a rotor that transmits the vibration excited on the circumscribed end face of the stator as a rotational motion by circumscribed contact with the stator; and Preload means for applying a required preload to the stator and the rotor, and forcibly imparting a rotational motion to the rotor based on the vibration excited on the circumscribed vibration end surface of the stator by the preload means. By transmitting the rotational motion to the joint part, the characteristic constituent means configured to bend the upper joint and the lower joint is taken.

  More specifically, in order to solve the problem, the present invention achieves the above-mentioned object by adopting a new characteristic configuration means ranging from the superordinate concept listed below to the subordinate concept. .

  That is, the first feature of the device of the present invention is an actuator applied to the joint part for bending and driving the joint upper part and the joint lower part of each of the two or more legs of the walking robot. A piezoelectric vibrator that vibrates natural vibration when a predetermined alternating voltage is applied to the joint portion, and a stator that excites arbitrary vibration on a circumscribed vibration end face; and the circumscribed vibration of the stator A rotor that transmits the vibration excited on the end face as a rotational motion by circumscribed contact with the stator, and a preload means that applies a required preload to the stator and the rotor, By forcibly applying the rotational motion to the rotor based on the vibration excited on the circumscribed vibration end surface of the stator by preload means, and transmitting the rotational motion to the joint portion, the joint upper portion and the joint Bending with the bottom It is configured so as to form comprising, in the configuration adopting joint actuator.

  A second feature of the device according to the present invention is that the joint actuator according to the first feature of the device according to the present invention protrudes while the lower end is fixed to the rotor, while the upper end faces the upper portion of the joint. The shaft is connected to transmit the rotational motion applied to the rotor to the thigh, and the piezoelectric vibrator is integrally laminated and fixed at a portion that becomes a vibration node of the stator. The joint actuator has a configuration in which a child is suspended in the air and includes a foot that lands on the walking surface of the walking robot below the joint and a stator suspension that is pivotally connected.

  A third feature of the device according to the present invention is that the joint actuator according to the first feature of the device according to the present invention is a walking robot in which the upper end sticks to the rotor and projects while the lower end faces the lower part of the joint. A shaft that is pivotally connected to the foot landing on the walking surface and transmits the rotational motion applied to the rotor to the foot, and the piezoelectric vibrator at a portion that becomes a vibration node of the stator The joint actuator is configured to include a stator suspension portion that is integrally laminated and fixed, and that suspends the stator in a hollow space and is connected to a thigh that faces the upper portion of the joint.

  A fourth feature of the device of the present invention is that the preload means in the second or third feature of the device of the present invention described above is a rotor idle gripping portion for gripping the rotor so as to be idle, the rotor and the fixed A preload-generating elastic body group that is placed symmetrically with the rotor in the middle and is stretched between the rotor idle gripping portion and the stator suspension portion to press-contact the rotor and the stator. The pre-load generating elastic body group is stretched in advance with a predetermined extension amount so as to constantly urge a tensile elastic force that antagonizes gravity acting on the lower end of the pre-load generating elastic body group. It is in configuration adoption.

  A fifth feature of the device according to the present invention is that the preload-generating elastic body group according to the fourth feature of the device according to the present invention is configured such that when the leg portion lands on the walking surface at the foot portion, the rotor When the leg part is separated from the walking surface and the leg part is a free leg, the rotor and the stator are The joint actuator has an elastic constant that reduces the tensile elastic force by the amount of extension of the preload-generating elastic body group due to gravity acting on the lower end of the preload-generating elastic body group, and has an elastic constant that can support the foot. It is in configuration adoption.

  A sixth feature of the device according to the present invention is that the actuator according to the second, third, fourth, or fifth feature of the device according to the present invention includes a neutral balance portion that is disposed opposite to the stator suspension portion, and the neutral A balance force generating elastic body group is stretched in parallel between the balance section and the stator suspension section on the opposite side of the preload generation elastic body group, and the balance force generation elastic body group is connected to the neutral balance section. The joint actuator has an elastic characteristic that always exerts a compressive elastic force when arranged at the upper part and has an elastic property that always exerts a tensile elastic force when the neutral balanced part is arranged at the lower part of the joint. It is in configuration adoption.

  A seventh feature of the device according to the present invention resides in the adoption of a joint actuator configuration in which the neutral balancing portion in the sixth feature of the device according to the present invention includes a bearing that penetrates and supports the shaft so as to slide up and down. .

  According to the present invention, by adopting an ultrasonic motor at the joint part of the walking robot, it becomes possible to exhibit high torque in a low speed range without mounting a speed reducer or the like, and the weight of the entire walking robot is reduced. Is possible. In addition, the maximum torque can be generated at the joint of the walking robot when the foot of the walking robot is landing on the walking surface, while the torque at the joint can be freed when it becomes a free leg. Therefore, a passive walk can be realized with a simple model.

  Furthermore, the walking motion of a walking robot can be achieved with a simple mechanism by canceling out the torque generated when the joint is bent due to the difference in the amount of elasticity of the elastic groups placed on the expansion side and the contraction side when bending. The weight of the entire walking robot can be further reduced.

  Hereinafter, embodiments 1 and 2 of the present invention will be described in order with reference to the accompanying drawings.

Embodiment 1
First, FIG. 1 is a side view showing a partial cross section of a joint actuator according to Embodiment 1 of the present invention. One leg of a walking robot having two or more legs β is landed on a walking surface G. It shows the state.

  As shown in the figure, the joint actuator α1 according to the first embodiment is an upper joint A1 of the joint A in each of two or more legs β of a walking robot for multi-leg walking such as biped walking. And an actuator applied to the joint part A for bending the joint lower part A2, and when a predetermined alternating voltage is applied to the joint part A, for example, each of them performs a flexural vibration in the pitch direction. A piezoelectric vibrator 11 and a piezoelectric vibrator 12 that performs stretching vibration in the vertical direction are stacked, and the piezoelectric vibrator 11 and the piezoelectric vibrator 12 are mechanically vibrated with a phase difference of 90 degrees to thereby provide a circumscribed vibration end face. The stator 1 which excites arbitrary vibration on S is provided.

  In addition, the joint actuator α1 transmits the vibration excited on the circumscribed vibration end surface S of the stator 1 as a rotational motion by the circumscribed contact with the stator 1, for example, a cylinder or a sphere that performs a rotational motion on the side surface. A rotor 2 having a spherical surface, and a preload means for applying a required preload to the stator 1 and the rotor 2. Here, for example, the rotor 2 has a center of rotation O, and the rotor In the case where a cylinder is employed for the joint 2, the bending of the joint upper part A1 and the joint lower part A2 is only a rotational movement in one axial direction, that is, only an inclination. In the invention according to the first embodiment, gears, pulleys, etc. No speed reducer is used.

  That is, the joint actuator α1 includes an ultrasonic motor including a stator 1, a rotor 2, and a preloading unit. Further, in the first embodiment, the lower end is fixed to the rotor 2 and protrudes. On the other hand, the upper end of the joint robot A1 faces the upper part of the upper joint A1, for example, is connected to the thigh B connected to the other leg β of the walking robot, and the rotational motion imparted to the rotor 2 is applied to the thigh B. The shaft 3a for transmitting to the arm and the stator 1 are suspended in the air and landed on the walking surface G of the walking robot below the lower joint A2, for example, the foot C composed of the ankle joint C1 and the landing C2 The stator suspension portion 4a is provided.

  The stator suspension portion 4a is integrated with the stator 1 together with the piezoelectric vibrators 11 and 12, at a place where the influence of vibration excited on the circumscribed vibration end surface S is small, that is, the stator 1 at the center of the stator 1 or the like. It is good to laminate and fix to the site | part used as the vibration node which excites, and it can prevent that the vibration of the stator 1 is transmitted to the stator suspension part 4a.

  Here, the preload means mounted on the joint actuator α1 includes, for example, a rotor idle gripping portion 5 that has a ball bearing 51 so as to grip the rotor 2 so that the rotor 2 can idle, and the stator 1 and the rotor 2 inside. A pre-load generating elastic body group 61, 62 which is placed symmetrically and stretched between the rotor idle gripping part 5 and the stator suspension part 4a and presses the rotor 2 and the stator 1 in pressure contact with each other. It is good to be configured.

  The preload-generating elastic body groups 61 and 62 are stretched by giving a predetermined extension amount in advance so as to urge a tensile elastic force that antagonizes gravity acting on the lower ends of the preload-generating elastic body groups 61 and 62. When the leg portion β on which the joint actuator α1 is mounted is landing on the walking surface G, all of the gravity acting on the thigh B of the member fixed to the upper end of the shaft 3a is used as the preload, and the shaft 3a. Thus, the stator 1 and the rotor 2 can be acted on each other, and a sufficient preload can be applied to the stator 1 and the rotor 2.

  Further, the joint actuator α1 is disposed opposite to the outer side of the preload-generating elastic body groups 61 and 62 over the rotor idle gripping part 5 and the stator suspension part 4a so as to face the stator suspension part 4a and move the shaft 3a up and down. For example, the balance force generating elastic body groups 81 and 82 are stretched in parallel between the neutral balance portions 7 that slidably pass through the bearing, for example, a cylindrical bearing 71 or the like that is attached to the center. In the first embodiment where the neutral balancing portion 7 is disposed at the joint upper part A1, the body groups 81 and 82 are disposed so as to have a splay elastic characteristic that always exerts a compressive elastic force.

  Note that the preload generating elastic body groups 61 and 62 and the balance force generating elastic body groups 81 and 82 rotate in the 0 ° limb position in which the joint part A is fully extended without bending. Although the fixed end on the side of the rotor 2 is arranged so as to be on the horizontal plane P, for example, the maximum preload is applied and the torque is compensated. By configuring each elastic body fixing end of the portion 7 so as to be fixed at a required height, it is possible to correspond to a prescribed elastic body.

  Further, the joint actuator α1 is arranged on the circumscribed spherical surface of the rotor 2 in the joint portion A, for example, when the range of motion of the joint portion A is restricted such that the upper joint portion A1 is not bent forward of the lower joint portion A2. When the rotation stopper 9 is fixed at a predetermined position, the rotation stopper 9 comes into contact with the circumscribed vibration end surface S when the rotational motion of the rotor 2 reaches a predetermined inclination angle, and the inclination is greater than this inclination angle. You may be comprised so that it may prevent.

  Next, FIG. 2 is a side view partially showing a state in which one leg of the walking robot to which the joint actuator shown in FIG. 1 is applied is a free leg away from the walking surface.

  As shown in the figure, the preload-generating elastic body groups 61 and 62 of the joint actuator α1 according to the first embodiment are configured so that the rotor 2 is in contact with the leg β when the leg C is landing on the walking surface G at the foot C. When the landing part C2 is separated from the walking surface G and the leg part β becomes a free leg, the rotor 2 and the stator 1 are preloaded. The tension elastic force is reduced by the amount of extension of the elastic body groups 61 and 62 that generate preload due to gravity acting on the lower ends of the elastic body groups 61 and 62, and the foot C can be separated from the walking surface G so that fishing can be supported. An elastic constant may be set.

  At this time, the tensile elastic force that is always applied to the preload generating elastic body groups 61 and 62 in advance is about the gravity acting on the lower ends of the preload generating elastic body groups 61 and 62, for example, the lower ends of the preload generating elastic body groups 61 and 62. If it is less than the gravity acting on the following members, the rotor 2 is separated from the circumscribed vibration end surface S of the stator 1, and no pre-pressure is generated between the stator 1 and the rotor 2.

  On the other hand, the tensile elastic force previously given to the preload generating elastic body groups 61 and 62 is about the gravity acting on the lower ends of the preload generating elastic body groups 61 and 62, for example, lower than the lower ends of the preload generating elastic body groups 61 and 62. When it is set to be greater than the gravity acting on the member, the preload can be greatly reduced while the stator 1 and the rotor 2 are pressed.

  When the leg β is a free leg, the stator 1 and the rotor 2 are greatly separated and the foot C is not separated from the walking surface G, or the preload-generating elastic body groups 61 and 62 are at the lower ends. The preload-generating elastic body groups 61 and 62 may have a sufficiently large elastic constant so that they do not extend to the extent that the elastic force cannot be exerted again due to the weight of the members connected below. desirable.

  As described above, by adopting the preload-generating elastic body groups 61 and 62 having an appropriate elastic constant, when the leg portion β of the walking robot to which the joint actuator α1 is applied is lifted to become a free leg, The preload applied to the stator 1 and the rotor 2 when the part β is landing on the walking surface G can be greatly reduced, and the posture of the joint upper part A1 and the joint lower part A2 in the joint part A can be reduced. The generation of torque can be switched so as not to generate a torque that holds the torque, and for example, a configuration optimal for a passive walk is made.

  Next, FIG. 3 is a side view showing a state in which a joint part of one leg of the walking robot to which the joint actuator shown in FIG.

  When the joint part A is bent, a load torque is generated in the joint part A according to the bending angle. Therefore, as shown in the figure, the balanced force generating elastic body groups 81 and 82 according to the first embodiment may be arranged symmetrically, for example, before and after the bending direction.

  At this time, for example, when the upper joint A1 and the lower joint A2 are bent in the paper surface, the horizontal plane P passing through the rotation center O is inclined by the inclination of the upper joint A1. Q, and the rotation axis of the rotor 2 is an orthogonal axis to the paper surface passing through the rotation center O of the rotor 2. That is, when the balancing force generating elastic body groups 81 and 82 and the neutral balancing portion 7 are fixed on the horizontal plane P, the fixed end of the balancing force generating elastic body groups 81 and 82 and the neutral balancing portion 7 is rotated. The expansion and contraction in the opposite direction is performed so as to be on the inclined surface Q passing through the center O.

  As a result, when the joint part A is bent, the stretching amount of each of the balance force generating elastic body groups 81 and 82 generates a difference between the tensile force and the compressive force before and after the bending, and generates an elastic force in the opposite direction. Thus, before and after the bending direction of the joint part A, it is possible to counterbalance the load torque by balancing and energizing the torque opposite to the load torque applied to the joint part A.

  The balance force generating elastic body groups 81 and 82 are fixed even when the joint portion A is bent because the shaft 3a is slidable up and down so that the neutral balance portion 7 includes the cylindrical bearing 71 and the like. The preload for the child 1 and the rotor 2 is not generated, and the balance force generating elastic body groups 81 and 82 are, for example, the preload generating elastic body group 61 and 82 before and after the bending performed by the joint portion A. The pre-load generating elastic bodies 61 and 62 are not limited to two elastic bodies as long as they are arranged symmetrically on the outer opposite side of 62.

Embodiment 2
FIG. 4 is a side view of the joint actuator according to the second embodiment of the present invention shown in a partial cross-section, and one leg of a walking robot having two or more legs β is landing on the walking surface G. Indicates the state. In addition, the same code | symbol shall be attached | subjected about the component same or equivalent to what was shown in FIG. 1, and the detailed description of the said component shall be abbreviate | omitted.

  As shown in the figure, the joint actuator α2 according to the second embodiment is mounted with the ultrasonic motor of the joint actuator α1 shown in the first embodiment turned upside down. That is, while the upper end is fixed to the rotor 2 and hangs down, the lower end is pivotally connected to the foot C landing on the walking surface G of the walking robot below the lower joint A 12, and the rotation applied to the rotor 2. The shaft 3b for transmitting the motion to the foot C and the piezoelectric vibrators 11 and 12 are integrally laminated and fixed at a portion that becomes a vibration node of the stator 1, and the stator 1 is suspended in a hollow space and above the upper joint A11. And a stator suspension portion 4b connected to the thigh B facing the rim.

  In the second embodiment as well, since an ultrasonic motor capable of exhibiting high torque performance in the low speed region is employed for the joint portion A, it is not necessary to use a speed reducer such as a gear or a pulley. For example, the rotor idle gripping portion 5 having a ball bearing 51 that grips the rotor 2 so as to be idled, and the stator 1 and the rotor 2 are placed in a symmetrical arrangement and fixed to the rotor idle gripping portion 5. It is possible to employ a preloading means having preload generating elastic body groups 61 and 62 which are stretched between the child suspension part 4b and press-contact the rotor 2 and the stator 1.

  At this time, the preload generating elastic body groups 61 and 62 are stretched in advance by giving a predetermined extension amount so as to urge a tensile elastic force that antagonizes gravity acting on the lower ends of the preload generating elastic body groups 61 and 62. Thus, when the leg β on which the joint actuator α2 is mounted is landing on the walking surface G, all the gravity acting on the thigh B of the member fixed to the upper end of the stator suspension portion 4b is preliminarily determined. The pressure can be applied to the stator 1 and the rotor 2 via the stator suspension 4b, and a sufficient pre-pressure can be applied to the stator 1 and the rotor 2.

  For example, when the leg β is landing on the walking surface G at the foot C, the preload-generating elastic body group 61, 62 always applies a tensile elastic force so as to press the rotor 2 and the stator 1 in pressure contact with each other. On the other hand, when the leg portion β becomes a free leg, the amount of extension of the preload-generating elastic body groups 61 and 62 due to the gravity acting on the lower ends of the preload-generating elastic body groups 61 and 62 when the rotor 2 and the stator 1 are free. The elastic constant may be set so as to reduce the tensile elastic force by the amount and to support the foot C.

  Note that the preload generating elastic body groups 61 and 62 and the balance force generating elastic body groups 81 and 82 having the splay elastic characteristics that always exert the tensile elastic force are in the 0 ° limb position where the joint actuator α2 is not bent. In the state, the fixed end on the rotor 2 side is disposed so as to be on a horizontal plane R passing through the rotation center O of the rotor 2, for example, so that the maximum preload is applied and the torque is compensated. However, for example, by setting the elastic body fixed ends of the rotor idle gripping portion 5 and the neutral balancing portion 7 to a required height, it is possible to correspond to a prescribed elastic body.

  As described above, the embodiments of the present invention have been described with reference to the first and second embodiments. However, the present invention is not necessarily limited to the above-described means. It is possible to implement changes.

  For example, the preload means is not limited to being constituted by the rotor idle gripping portion 5 and the preload generating elastic bodies 61 and 62, and applies a required preload to the stator 1 and the rotor 2. As long as the rotor 2 can be forcibly given an arbitrary rotational motion by frictionally driving the rotor 2 on the circumscribed vibration end surface S of the vibrating stator 1, for example, magnetic force, atmospheric pressure, etc. It is also possible to drive the joint actuators α1 and α2 by applying a pre-pressure using.

  Further, the neutral balancing portion 7 is a single right-angled parallel bending beam having one end of a balancing force generating elastic body group 81, 82 fixed thereto and a cylindrical bearing 71 or the like that penetrates and supports the shaft 3a or the shaft 3b. Although described as a shape, instead of a right-angle parallel bending beam shape, a right-angle parallel bending radiation beam shape or a cylindrical dish type disk shape may be used.

  Furthermore, in the present embodiment example, the joint actuators α1 and α2 have been described as being applied to the knee joint as the joint portion A, but are not limited to the knee joint, for example, applied to the ankle joint portion C1. In the leg part β, it is also possible to make a joint mechanism between the lower limb and the landing part C2.

  In addition, the neutral balance portion 7 has been described as penetrating a bearing such as a cylindrical bearing that allows the shafts 3a and 3b to slide up and down. However, the neutral balance portion 7 does not have the cylindrical bearing 71 mounted thereon, and the shaft 3a , 3b may be directly fixed.

  At this time, at the time of the free leg shown in FIG. 2, the balanced force generating elastic body groups 81 and 82 having a predetermined elastic constant and given a predetermined tensile elastic force in advance are stretched, The joint part A can be brought into a torque-free state, and the joint part A elastic body groups 81 and 82 are extended even when the joint part A shown in FIG. 3 is bent. It is possible to compensate the load torque generated at the time of bending by the tensile elastic force of the balance force generating elastic body 81.

It is the side view shown in the partial cross section of the joint actuator which concerns on Example 1 of Embodiment of this invention. It is the side view which showed the state where one leg of the walking robot to which the joint actuator same as the above is applied is a free leg away from the walking surface. It is the side view which showed the state where the joint part of the one leg of the walking robot to which the joint actuator same as the above was bent was shown in a partial cross section. It is the side view shown in the partial cross section of the joint actuator which concerns on Example 2 of Embodiment of this invention.

Explanation of symbols

α1, α2 ... joint actuator β ... leg A ... joint A1, A11 ... upper joint A2, A12 ... lower joint B ... thigh C ... foot C1 ... ankle joint C2 ... landing part G ... walking surface O ... Rotation center P, R: horizontal plane passing through the rotation center O of the rotor 2 Q: inclined surface S ... circumscribed vibration end surface 1 ... stator 11, 12 ... piezoelectric vibrator 2 ... rotor 3a, 3b ... shaft 4a, 4b ... fixed Child suspension part 5 ... Rotor idle gripping part 51 ... Ball bearings 61 and 62 ... Preload generation elastic body group 7 ... Neutral balance part 71 ... Cylindrical bearing 81 and 82 ... Balance force generation elastic body group 9 ... Rotation stopper

Claims (6)

In each of the two or more legs of the walking robot, an actuator applied to the joint part for bending and driving the joint upper part and the joint lower part of the joint part,
In the joint,
Laminating a piezoelectric vibrator that vibrates natural vibration when a predetermined alternating voltage is applied, and a stator that excites arbitrary vibration on the circumscribed vibration end face;
A rotor that transmits the vibration excited on the circumscribed end face of the stator as a rotational motion by circumscribed contact with the stator;
Preload means for applying a required preload to the stator and the rotor ;
A shaft that is fixed to the rotor and protrudes while the lower end is fixed to the thigh that faces the upper upper part of the joint, and that transmits the rotational motion applied to the rotor to the thigh,
A leg and a pivot that are integrally laminated and fixed together with the piezoelectric vibrator at a portion that becomes a vibration node of the stator, suspending the stator in a hollow space, and landing on a walking surface of the walking robot below the joint. A tied stator suspension ,
The preload means is
A rotor idling gripping part for gripping the rotor idlingly;
Pre-load generation in which the rotor and the stator are placed in a symmetrical arrangement and stretched between the rotor idle gripping part and the stator suspension part to press the rotor and the stator in pressure contact An elastic body group,
The preload-generating elastic body group is
The preload generating elastic body group is stretched by giving a predetermined extension amount in advance so as to constantly urge a tensile elastic force that antagonizes gravity acting on the lower end of the elastic body group,
The rotational movement force imparted to the said rotor on the basis of the vibration excitation on said enclosing vibration end surface of the stator by the preload means, by transmitting the rotational motion to the joint portion, the said joint upper Configured to flex with the lower joint,
A joint actuator characterized by that. In each of the two or more legs of the walking robot, an actuator applied to the joint part for bending and driving the joint upper part and the joint lower part of the joint part,
In the joint,
Laminating a piezoelectric vibrator that vibrates natural vibration when a predetermined alternating voltage is applied, and a stator for exciting arbitrary vibration on the circumscribed vibration end face;
A rotor that transmits the vibration excited on the circumscribed end face of the stator as a rotational motion by circumscribed contact with the stator;
Preload means for applying a required preload to the stator and the rotor ;
The upper end is fixed to the rotor and hangs down, while the lower end is pivoted to a foot landing on the walking surface of the walking robot facing the lower part of the joint, and the rotational motion imparted to the rotor is A shaft that transmits to the foot,
A stator suspension part that is integrally laminated and fixed together with the piezoelectric vibrator at a portion that becomes a vibration node of the stator, and that the stator is suspended in the air and is connected to a thigh that faces the upper part of the joint; And comprising
The preload means is
A rotor idling gripping part for gripping the rotor idlingly;
Pre-load generation in which the rotor and the stator are placed in a symmetrical arrangement and stretched between the rotor idle gripping part and the stator suspension part to press the rotor and the stator in pressure contact An elastic body group,
The preload-generating elastic body group is
The preload generating elastic body group is stretched by giving a predetermined extension amount in advance so as to constantly urge a tensile elastic force that antagonizes gravity acting on the lower end of the elastic body group,
The rotational movement force imparted to the said rotor on the basis of the vibration excitation on said enclosing vibration end surface of the stator by the preload means, by transmitting the rotational motion to the joint portion, the said joint upper Configured to flex with the lower joint,
A joint actuator characterized by that. The preload generating elastic body group is:
When the leg portion lands on the walking surface at the foot portion, the tensile elastic force is applied to press the rotor and the stator, while the foot portion is separated from the walking surface. When the leg portion becomes a free leg, the tensile elastic force is reduced by the amount of extension of the preload-generating elastic body group due to gravity acting on the rotor and the stator on the lower end of the preload-generating elastic body group. Along with an elastic constant that enables fishing of the foot,
The joint actuator according to claim 1 or 2 . The actuator is
A neutral equilibrium portion disposed opposite to the stator suspension;
Stretching the balance force generating elastic body group in parallel between the neutral balance part and the stator suspension part on the outer side opposite to the preload generating elastic body group,
The balanced force generating elastic body group is
When the neutral balanced part is arranged at the upper part of the joint, the compression elastic force is constantly exerted, and when the neutral balanced part is arranged at the lower part of the joint, the tensile elastic force is always exerted.
The joint actuator according to any one of claims 1 to 3 . In each of the two or more legs of the walking robot, an actuator applied to the joint part for bending and driving the joint upper part and the joint lower part of the joint part,
In the joint,
Laminating a piezoelectric vibrator that vibrates natural vibration when a predetermined alternating voltage is applied, and a stator that excites arbitrary vibration on the circumscribed vibration end face;
A rotor that transmits the vibration excited on the circumscribed end face of the stator as a rotational motion by circumscribed contact with the stator;
Preload means for applying a required preload to the stator and the rotor ;
A shaft that is fixed to the rotor and protrudes while the lower end is fixed to the thigh that faces the upper upper part of the joint, and that transmits the rotational motion applied to the rotor to the thigh,
A leg and a pivot that are integrally laminated and fixed together with the piezoelectric vibrator at a portion that becomes a vibration node of the stator, suspending the stator in a hollow space, and landing on a walking surface of the walking robot below the joint. A tied stator suspension,
A neutral equilibrium portion disposed opposite to the stator suspension;
A balanced force generating elastic body group which is stretched in parallel between the neutral balanced portion and the stator suspension portion and has an elastic characteristic that constantly exerts a compressive elastic force .
The rotational movement force imparted to the said rotor on the basis of the vibration excitation on said enclosing vibration end surface of the stator by the preload means, by transmitting the rotational motion to the joint portion, the said joint upper Configured to flex with the lower joint,
A joint actuator characterized by that. In each of the two or more legs of the walking robot, an actuator applied to the joint part for bending and driving the joint upper part and the joint lower part of the joint part,
In the joint,
Laminating a piezoelectric vibrator that vibrates natural vibration when a predetermined alternating voltage is applied, and a stator that excites arbitrary vibration on the circumscribed vibration end face;
A rotor that transmits the vibration excited on the circumscribed end face of the stator as a rotational motion by circumscribed contact with the stator;
Preload means for applying a required preload to the stator and the rotor ;
The upper end is fixed to the rotor and hangs down, while the lower end is pivoted to a foot landing on the walking surface of the walking robot facing the lower part of the joint, and the rotational motion imparted to the rotor is A shaft that transmits to the foot,
A stator suspension part that is integrally laminated and fixed together with the piezoelectric vibrator at a portion that becomes a vibration node of the stator, and that the stator is suspended in the air and is connected to a thigh that faces the upper part of the joint; ,
A neutral equilibrium portion disposed opposite to the stator suspension;
A balanced force generating elastic body group which is stretched in parallel between the neutral balanced portion and the stator suspension portion and has an elastic characteristic that constantly exerts a tensile elastic force ;
The rotational movement force imparted to the said rotor on the basis of the vibration excitation on said enclosing vibration end surface of the stator by the preload means, by transmitting the rotational motion to the joint portion, the said joint upper Configured to flex with the lower joint,
A joint actuator characterized by that.

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