JPH033654A - Articular motion actuator - Google Patents

Abstract

PURPOSE:To improve the response of an apparatus by constituting the apparatus from a stator forming a magnetic circuit from electromagnets, first and second couplings, a movable element provided with a core arranged on the circumference in the manner of facing each electromagnet, and an articular motion output member mounted on the movable element and extending in the direction of the movable element axial center. CONSTITUTION:A stator 15 forming a magnetic circuit from electromagnets 1 respectively arranged at plural places on the circumference and a movable element 14 provided with a core 3 arranged on the circumference in the manner of facing said electromagnets 1 are connected by coupling parts 5, 17 respectively provided at both parts 15, 14 so as to enable an articular motion relatively, and an articular motion output member 9 extending in the direction of the axial center is mounted on the movable element 14. Therefore, when the strength of a current flowing through each electromagnet 1 is changed, a force attracting the core 3 of the movable element 14 varies on the circumference so that the movable element 14 can perform a specified articular motion and a specified attitude control relative to the articular motion output member 9.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a joint movement actuator that drives the movement of joints in devices such as machine tools and industrial robots.

[Conventional technology]

Conventionally, joint movement actuators that achieve the movement of joints in machine tools, robots, etc.
Using each drive mechanism in the axial direction, the motion in each axial direction is driven by an electric motor that operates the respective drive mechanism, thereby obtaining a compound motion that combines the motion in each axial direction and achieving a predetermined overall motion. The current situation is that joint movement has been achieved.

Moreover, as an articulation bearing device used in an evisic motor, those shown in FIGS. 3, 4, and 5 are disclosed. The joint motion bearing device supports a rolling element using a spherical joint as a pivot shaft so that it can swing and rotate, that is, pivot, by magnetic force.As shown in FIG. The children or stators 30 are 6
Fixed pole electromagnets 31 are arranged on the circumference. As shown in FIG. 4, a rotor 33, which is a rolling element, is arranged to face the stator 30. As shown in FIG.

The electromagnet 31 in the stator 30 is constructed by winding a stator coil 32 around an iron core 38.

The rotor 33 is pivotally supported by a spherical joint 35 around the center. On the outer periphery of the rotor 33,
A conical transfer surface 37 is formed.

A conical rolling surface 37 of the rotor 33 is positioned opposite a conical raceway surface 36 of a frame 34 which is axially fixedly mounted. In this articulation bearing device, the state shown in FIG. 4 is a state in which each electromagnet 31 is not energized, and the conical apex angle α of the conical raceway surface 36 of the frame 34 is the same as that of the conical rolling surface 37 of the rotor 33. It is set slightly larger than the apex angle β. Further, FIG. 5 shows a state in which each electromagnet 31 in this articulation bearing device is excited. In this state, since the rotor 33 is shifted, low-speed rotation is simply extracted from the shaft of the rotor 33.

[Problem to be solved by the invention]

However, in the joint movement actuator described above, which performs a predetermined joint movement using drive mechanisms in the three-axis directions of the X, Y, and Z axes, the number of parts is small because the movement of each drive mechanism is performed. The mechanism itself is complicated, the power transmission system is an indirect transmission, the friction loss associated with the transmission is large, and there is a lot of information for each movement of each drive mechanism, and based on this large amount of information, Errors occur in the calculation, which adversely affects accuracy, and the use of a large number of electric motors increases costs.

The purpose of this invention is to solve the above problems,
It is applied to the output part of the power transmission system in various devices such as machine tools and industrial robots, and one drive device allows the output part to perform joint movements such as conical movement, rocking movement, rotational movement, etc. The controller directly generates motion, causes the output section to accurately and quickly perform the motion state, and transmits the predetermined motion to a driven body such as an operating member or workpiece attached to the output section. To provide a joint movement actuator that improves response and accuracy by reducing input information, has simple control and structure, reduces costs, and can obtain extremely simple and effective predetermined joint movements depending on the purpose of use. It is to be.

(Means for Solving the Problems) In order to achieve the above object, the present invention is configured as follows.That is, the present invention provides a magnetic circuit using electromagnets arranged at a plurality of locations on the circumference. stator, forming
a fixed shaft fixed to the center of the stator and having a first seam portion at the tip; a 2411th seam portion movably connected to the first seam portion; and facing each of the electromagnets. The present invention relates to an articulation actuator comprising a movable element having an iron core arranged on the circumference, and an articulation output member attached to the movable element and extending in the axial direction of the movable element.

Here, the joint movement refers to a pivot movement that performs a rocking movement such as a conical movement and a rotation movement simultaneously or independently, and a movement that maintains a relatively stationary state.

Further, this articulation actuator changes the magnitude of the current supplied to each of the 11 magnets of the stator to change the magnetic force applied between each of the iron cores of the movable element.

Furthermore, this joint movement actuator includes an angle sensor that detects an inclination angle and an inclination direction of the movable element with respect to the fixed axis, and controls magnetic force between each of the electromagnets and each of the iron cores in response to a detection signal of the angle sensor. and a controller that controls the motion and posture of the joint motion output member to predetermined setting conditions.

[Effect]

The articulation actuator according to the present invention is constructed as described above, and thus operates as follows. That is, this articulation actuator includes a stator that forms a magnetic circuit using electromagnets placed at a plurality of locations on the circumference, and a mover that includes an iron core that is placed on the circumference facing the tta stone. , both of them are connected to each other so that they can move relative to each other by joint halves, and a joint movement output member that extends in the axial direction is attached to the movable element, so that the strength of the current flowing through each electromagnet can be controlled. By making various changes, the force with which the iron core of the movable element is attracted differs on the circumference, thereby allowing the movable element to perform a predetermined joint movement, and the force of attracting the iron core of the movable element to change in various ways. The motion output member can perform a predetermined joint motion, such as a conical motion, a rotational motion, a rocking motion, or a pivot motion, or a predetermined attitude control for the joint motion output member. Further, the iron core may be a plurality of iron cores arranged at a plurality of locations facing the magnet, or a ring-shaped wound iron core, which can perform the same function.

C Embodiment] Hereinafter, embodiments of the joint movement actuator according to the present invention will be described with reference to the drawings.

FIG. 1 is a plan view showing one embodiment of the articulation actuator according to the present invention, and showing the portion taken along line 1--1 in FIG. FIG. 2 is a sectional view showing an embodiment of the joint-linked actuator according to the present invention.

As shown in FIG. 2, the articulation actuator according to the present invention mainly consists of ! [Constructed of a stator 15 that forms a magnetic circuit with stones 1, a movable element 14 that is disposed opposite to the stator 15 so as to be able to swing and rotate, and a joint motion output member 9 that is attached to the movable element 14.] has been done. The stator L5 includes a yoke portion 13 that constitutes a support portion, and a plurality of electromagnets l arranged at equal intervals on the circumference of the yoke portion 13. The electromagnet 1 is constructed by winding an excitation coil 2 around the outer periphery of a stator core 16.

Further, at the central portion of the cork portion 13, that is, at the center on the circumference where each electromagnet 1 is located, a fixed shaft 6 extends in the axial direction parallel to each electromagnet 1 and is fixed to the yoke portion 13. A bearing spherical surface portion 5, which is a first joint half, is integrally formed at the tip of the fixed shaft 6. The movable element 14 disposed opposite the stator I5 includes a movable member 4 serving as a rolling element, and an annular wound core 3 disposed facing the circumference of the movable member 4. As for the iron core, as shown in the diagram,
It may be constructed from a wound iron core 3, or it may be constructed from a plurality of iron cores arranged at equal intervals on the circumference of the movable member 4, although not shown.

In FIG. 1, the arrangement of the electromagnets 1 of the stator 15 in the articulation actuator according to the present invention is shown on the right, and the arrangement of the wound core 3 of the mover 14 is shown on the left. That is, in FIG. 1, six electromagnets 1 of the stator 15 are arranged, as an example, based on the arrangement shown on the left and right sides.

In addition, at the center portion of the movable member 4, that is, the center portion on the circumference where the wound core 3 is located, there is a bearing spherical surface that is a second joint half portion that is pivotally and rotatably fitted into the fixed shaft 60 and the bearing spherical surface portion 5. Fitting part 17
is formed. An annular groove 18 is formed on the inner peripheral surface of this bearing spherical fitting portion 17, and a bush 12 is provided in the annular groove 18.
is inserted. Further, a large number of fitting holes 19 are formed on the outer periphery of the bearing spherical portion 5 of the fixed shaft 6, and the balls 7 are fitted into the fitting holes 19. Further, a joint motion output member 9 extending in the axial direction of the movable element is fixed to the movable member 4 constituting the movable element 14 via a connecting member 8. This joint motion output member 9 serves, for example, as a work output member, a support output member such as a chuck, and the like. Therefore, in this articulation actuator, between the bearing spherical surface portion 5 of the fixed shaft 6 and the bearing spherical surface fitting portion 17 of the movable member 4,
Relative rocking rotational movement, e.g. conical movement, rotational movement,
It is configured to have a structure capable of performing relative movements such as rocking motion, a relatively tilted state at a predetermined angle, and a function of maintaining an axially aligned state. Although not shown, it goes without saying that the first joint half may be configured as a bearing spherical surface fitting portion and the second joint half portion may be configured as a bearing spherical surface portion.

Furthermore, in the joint motion actuator according to the present invention, an angle sensor is provided at the center of the end of the bearing spherical surface portion 5 of the fixed shaft 6 fixed to the stator 15 to detect the inclination angle and the direction of inclination of the movable element 14 with respect to the fixed shaft 6. 11 are provided. Detection signals sequentially detected by this angle sensor 11 are input to the controller IO. The detection signal value input to the controller 1O is compared with preset values such as the tilt angle, tilt direction, successive displacement angle, displacement speed, etc., and is calculated. A command is issued to supply current to the excitation coil 2 of the stone l. In this way, the angle sensor 11
In other words, the angle of inclination of the stator 15 and the mover 1
The detection signal of the state of the air gap between the electromagnets 1 and 4 is automatically fed back sequentially and input into the controller 10 and calculated, thereby increasing or increasing the strength of the current supplied to the excitation coil 2 of each electromagnet 1. The excitation state of the magnetic force, that is, the magnetic field between each electromagnet 1 and each wound core 3 is automatically controlled accordingly, and the movable member 4
The movable member 4 is controlled to maintain a predetermined posture, or the movement of the movable member 4 is controlled to a predetermined state of motion. The torque and tilting motion of the movable member 4 is caused by the joint movement output member 9, which is a work output rod.
is transmitted. Therefore, the load attached to the joint motion output member 9 is controlled to move according to the predetermined setting conditions, and its posture is adjusted to the posture according to the predetermined setting conditions, that is, its posture is controlled.

The operation of the joint movement actuator according to the present invention will be explained. Now, if a rotating magnetic field is created with three-phase alternating current by the six excitation coils 2 of the stator 15, the wound core 3 of the mover 14 will rotate around the bearing spherical surface 5 due to the rotational torque caused by the eddy current, and the joint motion will be output. The member 9 transmits its rotational torque to a load attached to the articulation output member 9. Here, for example, when only the excitation coil 5 of one electromagnet 1 in the stator 15 is excited, the movable element 14 is attracted and tilted in the direction in which the excited i-magnet 1 is located. In addition, in order to tilt the mover 14 in the left and right directions, the excitation coils 2 of the two electromagnets 1 located at the target positions are simultaneously excited, so that they act in a tug-of-war, that is, a state where they are pulled together. The position of the movable element 14 is controlled to be maintained at a desired predetermined inclined position by the difference in magnetic force generated by the difference in the strength of the current. As a result, the joint motion output member 9 fixed to the movable element 14 maintains a necessary spatial position, that is, posture due to the inclined posture of the movable element 14, and the load attached to the joint motion output member 9 is required for the work. becomes possible. In addition, when the movable member 4 of the mover 14 is tilted to a position between the finite number of electromagnets 1 of the stator 15, the left and right electromagnets 1 are used together to maintain the intermediate position of the electromagnet 1. This can be achieved by supplying current to the excitation coil 2 of the electromagnet 1 and controlling the magnetic force therebetween. Therefore, as described above, by controlling the excitation of the excitation coils 2 of two or more electromagnets 1, the mover 14 can
It is possible to maintain various postures such as an arbitrary conical inclined posture and a vertical posture, or the tip of the joint motion output member 9 can perform various movements such as arbitrary curved movement and rotational movement in an inclined posture.

Since the articulation actuator according to the present invention is constructed and operated as described above, it can be applied to various devices such as machine tools and industrial robots.

For example, when performing taper machining on a workpiece in a wire-cut electric discharge machine, in addition to drive devices or actuators for the X-axis, 7-wheel, and Z-axis of the table, carriage, and the like, conventionally, actuators for the U-axis and V-axis are used. However, if the articulation actuator according to the present invention is used, this can be achieved with a single actuator.

In addition, the wrist portion of an industrial robot, that is, the joint movement unit, conventionally performs rocking and rotational joint movements by three-axis actuators of the X, Y, and Z axes, but the joint movement according to the present invention By using an actuator, a conical movement within a certain angular range and a complete rotational movement can be realized, and thus can be similarly achieved with a single actuator.

〔Effect of the invention〕

Since the joint motion actuator according to the present invention is configured as described above, it has the following effects. That is, this joint movement actuator includes a stator that forms a magnetic circuit with electromagnets arranged at multiple locations on the circumference;
A fixed shaft fixed to the center of the stator and having a first joint portion at the tip thereof, a second joint half portion articulably connected to the first joint portion, and a circumferential shaft opposite to each of the electromagnets. Since it is composed of a movable element having an iron core disposed above and a joint movement output member attached to the movable element and extending in the axial direction of the movable element, it is possible to vary the strength of the current flowing through each of the electromagnets. Accordingly, the movable element can perform a predetermined joint movement, and in accordance with the movement of the movable element, the joint movement output member performs a predetermined joint movement such as a conical movement, a rotational movement, a rocking movement, or a predetermined posture. can be controlled,
It is possible to cause the load attached to the joint motion output member to perform a predetermined work.

For example, when processing a workpiece such as taper processing, by using one of these joint motion actuators, it is possible to give a predetermined posture and motion to the workpiece. In addition, when applied to the wrist part of an industrial robot, that is, the joint movement part, by using one joint movement actuator, it is possible to perform rocking movement such as conical movement and rotational movement within a predetermined angular range. Joint movement, ie pivot movement, can be realized. Further, the magnetic force of the electromagnet is directly transmitted to the joint motion output member, and desired posture control can be performed using only information for operating one actuator, thereby improving the response of joint motion.

Furthermore, this articulation actuator changes the magnitude of the current supplied to each of the i-magnets of the stator to change the magnetic force applied between each of the iron cores of the mover, thereby increasing or decreasing the magnetic field. For example, when tilting the joint motion output member left and right, the electromagnets located in the left and right directions are pulled together. It can be controlled so that the inclination can be maintained in a certain direction by excitation. Further, when tilting the electromagnets to an intermediate position between the maximum number of electromagnets, both electromagnets located in the direction are energized to maintain the joint motion output member tilted to the intermediate position. .

Furthermore, this joint movement actuator includes an angle sensor that detects an inclination angle and an inclination direction of the movable element with respect to the fixed axis, and controls magnetic force between each of the electromagnets and each of the iron cores in response to a detection signal of the angle sensor. and a controller for controlling the motion and posture of the joint motion output member to predetermined setting conditions. Feedback is sent to the controller, and in response to the successive detection signals, the motion and posture of the joint motion output member can be controlled quickly and accurately to desired conditions at all times.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an embodiment of the articulation actuator according to the present invention, FIG. 2 is a sectional view of the articulation actuator of FIG. 1, and FIG. 4 is a schematic diagram showing an example of a bearing joint in a non-excited state that can swing and rotate, and FIG. 5 is a schematic diagram showing an example of a bearing joint that can swing and rotate in an energized state. It is. 1-... Electromagnet, 2-...-Magnetic coil, 3-
---One-turn iron core, 4.--.--Movable member, 5--1.
-Bearing spherical portion (first joint half), 6--Fixed shaft, 9--Joint motion output member, 10--
~-Controller, 11-- Angle sensor, 14-
・-Mover, 15--Stator, 16--
Stator core, 17---Bearing spherical fitting part (second joint half part).

Claims (3)

[Claims] (1) A stator that forms a magnetic circuit using electromagnets arranged at multiple locations on the circumference, a fixed shaft that is fixed at the center of the stator and has a first joint section at its tip, and a fixed shaft that has a first joint section at its tip; a movable element that is provided with a second joint part that connects to enable articulation and that is disposed on a circumference facing each of the electromagnets, and a joint that is attached to the movable element and extends in the axial direction of the movable element; An articulation actuator comprising an output member. (2) The joint movement according to claim 1, characterized in that the magnitude of the current supplied to each of the electromagnets of the stator is changed to change the magnetic force applied between each of the iron cores of the movable element. actuator. (3) An angle sensor that detects the inclination angle and direction of the movable element with respect to the fixed axis, and controls the magnetic force between each of the electromagnets and each of the iron cores in response to a detection signal of the angle sensor to move the joint. The joint motion actuator according to claim 1, further comprising a controller that controls the motion and posture of the output member to predetermined setting conditions.