JP2022103668A - Actuator, and robot - Google Patents

Abstract

To provide an actuator and the like capable of suppressing vibration at the operation time by enhancing flexural rigidity of a rod.SOLUTION: An actuator 100 includes: a ball screw shaft where a rotational motion of an output shaft of a motor is transmitted; a ball screw nut provided at the ball screw shaft; a slide part 160 having a first holding part 186 where the ball screw nut is mounted and a second holding part 187 which is overlapped with the first holding part 186, and performing a linear motion according to the rotational motion of the ball screw shaft; a tubular first rod 175 whose one end is held at the first holding part 186; a tubular second rod 176 whose one end is held at the second holding part 187; and a tip bracket 190 for connecting the first rod 175 and the second rod 176 at the other ends respectively. The ball screw shaft penetrates the first holding part 186, and one end is rotatably supported on an inner peripheral surface of the first rod 175.SELECTED DRAWING: Figure 2

Description

The present invention relates to actuators and robots.

An actuator that linearly moves the operating rod in the axial direction using a ball screw has been put into practical use. For example, Cited Document 1 discloses an actuator in which an operating rod is provided in the center, and when the ball screw shaft is rotated by a motor, a nut screwed to the ball screw shaft moves the operating rod in the axial direction.

Jitsufuku No. 2-5143 Gazette

In the actuator of Patent Document 1, as the amount of movement set in the actuating rod is large and the length in the longitudinal direction of the actuator becomes long, the bending rigidity of one actuating rod tends to be insufficient and vibration tends to occur. On the other hand, although FIG. 6 of Cited Document 1 discloses an actuator provided with a pair of rods, the bending rigidity in a direction other than the direction in which the rods are lined up can be made larger than that of a single operating rod. It is not enough to suppress the vibration of things, and vibration is still likely to occur.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an actuator and a robot capable of increasing the bending rigidity of a rod and suppressing vibration during operation. ..

The actuator according to the present invention has a ball screw shaft that rotates by transmitting the rotational movement of the output shaft of the motor, a ball screw nut provided on the ball screw shaft, and a first holding to which the ball screw nut is attached. A tubular portion having a portion and a second holding portion that overlaps the first holding portion, and having a slide portion that linearly moves with the rotational movement of the ball screw shaft, and a tubular portion whose one end is held by the first holding portion. The ball includes a first rod, a tubular second rod whose one end is held by the second holding portion, and a tip bracket that connects the first rod and the second rod at their respective other ends. The screw shaft penetrates the first holding portion, and one end thereof is rotatably supported by the inner peripheral surface of the first rod.

The second holding portion is formed with a through hole connected to the hollow portion formed in the second rod, and the tip bracket has an opening connected to the hollow portion formed in the second rod. It may be formed, and a passage for passing wiring from the second holding portion through the second rod and penetrating the tip bracket may be formed.

The slide portion may be provided with a wiring fixture for fixing the intermediate portion of the wiring passing through the passage.

The second holding portion further includes a tubular third rod whose one end is held, and when the slide portion is viewed from the direction of linear motion, the first rod, the second rod, and the third rod are respectively. It may be arranged so that the center of is located at the apex of the isosceles triangle.

The second holding portion is formed with a through hole connected to the hollow portion formed in the third rod, and the tip bracket has an opening connected to the hollow portion formed in the third rod. It may be formed, and a passage for passing wiring from the second holding portion through the third rod and penetrating the tip bracket may be formed.

A base body that supports the slide portion in a linear motion may be further provided, and a rolling element that rolls continuously along the moving direction of the slide portion may be interposed between the slide portion and the base body. ..

At one end of the ball screw shaft, a steady rest member that comes into contact with the inner peripheral surface of the first rod and suppresses the runout of the first rod may be provided.

The robot according to the present invention includes the actuator in which the second actuator is attached to the tip bracket, and the wiring of the second actuator is guided from the tip bracket through at least the hollow portion of the second rod. ..

According to the present invention, it is possible to provide an actuator and a robot capable of increasing the bending rigidity of a rod and suppressing vibration during operation.

The perspective view of the robot to which the actuator which concerns on embodiment of this invention is applied. An exploded perspective view of the actuator according to the embodiment of the present invention. Sectional drawing of the actuator in cutting line III-III in FIG. FIG. 2 is a cross-sectional view of the actuator at the cutting line IV-IV in FIG. The perspective view of the drive mechanism which the actuator which concerns on embodiment of this invention has. A side view of the drive mechanism as seen from the arrow VI in FIG. An exploded perspective view of a drive mechanism included in the actuator according to the embodiment of the present invention. An exploded perspective view of a drive mechanism included in the actuator according to the embodiment of the present invention. An exploded perspective view of the drive unit shown in FIG. 7. An exploded perspective view of the urging portion shown in FIG. 7. FIG. 6 is a cross-sectional view when the royal fern mechanism shown in FIG. 7 is in the released state. FIG. 6 is a cross-sectional view when the royal fern mechanism shown in FIG. 7 is in the hoisting state. An exploded perspective view of the speed-increasing portion shown in FIG. 7. FIG. 6 is a cross-sectional view of a drive mechanism in the cutting line XIV-XIV in FIG. FIG. 6 is a cross-sectional view of a drive mechanism in the cutting line XV-XV in FIG. FIG. 6 is a cross-sectional view of a drive mechanism in the cutting line XVI-XVI in FIG. An enlarged view of the "XVII" part in FIG. An enlarged view of the "XVIII" part in FIG. FIG. 2 is a perspective view of the slide portion shown in FIG. Enlarged view of "XX" part in FIG. An enlarged view of the "XXI" part in FIG. FIG. 2 is a cross-sectional view of the actuator in the cutting line XXII-XXII in FIG. It is a figure for demonstrating the operation of an actuator, and is the side view which showed the state ((a)-(c)) that a rod gradually protrudes.

Hereinafter, the actuator and the robot according to the embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, orthogonal coordinates in which the X-axis, Y-axis, and Z-axis are defined are defined, and these orthogonal coordinates will be described as appropriate. Here, the + Z-axis direction is upward, and the −Z-axis direction is downward. That is, the X-axis and the Y-axis are parallel in the horizontal direction, and the Z-axis is parallel in the vertical direction.

(Outline of Robot 1 to which Actuator 100 for Z-axis is applied)
As shown in FIG. 1, the robot 1 to which the actuator 100 according to the embodiment of the present invention is applied has an actuator 10 for an X-axis arranged along the X-axis in the longitudinal direction and an actuator 10 for the X-axis in the longitudinal direction. An actuator 20 for the Y axis arranged along the axis, an actuator 100 for the Z axis arranged along the Z axis in the longitudinal direction, a wrist unit 30 provided at one end of the actuator 100 for the Z axis, and a wrist. It is provided with a gripper 40 provided in the unit 30. Further, in the present embodiment, the wrist unit 30 and the gripper 40 are installed, but the present invention is not limited to this. It may be a wrist unit, another tool other than the gripper, an electronic device, or an air-driven device.

The actuator 10 for the X-axis has a ball screw for the X-axis (not shown) arranged along the X-axis direction, and a motor for the X-axis (not shown) for driving the ball screw for the X-axis. The XY bracket 11 is fixed to a ball screw nut (not shown) for the X axis, and by controlling the rotation direction and the amount of rotation of the output shaft of the motor for the X axis, the XY bracket 11 is moved along the X axis. It can be moved linearly and stopped at a desired position. The XY bracket 11 holds the actuator 20 for the Y axis. As a result, the XY bracket 11 moves along the X-axis direction, so that the actuator 20 for the Y-axis can be moved along the X-axis direction.

The actuator 20 for the Y-axis has a ball screw for the Y-axis (not shown) arranged along the Y-axis direction and a motor for the Y-axis (not shown) for driving the ball screw for the Y-axis. The YZ bracket 21 is fixed to a ball screw nut (not shown) for the Y axis, and by controlling the rotation direction and the amount of rotation of the output shaft of the motor for the Y axis, the YZ bracket 21 is moved along the Y axis. It can be moved linearly and stopped at a desired position. The YZ bracket 21 holds the actuator 100 for the Z axis. As a result, the YZ bracket 21 moves along the Y-axis direction, so that the actuator 100 for the Z-axis can be moved along the Y-axis direction.

As shown in FIGS. 3 and 4, the Z-axis actuator 100 is arranged along the Z-axis direction and drives the Z-axis ball screw shaft 101 and the Z-axis ball screw shaft 101. It has a motor 120 for use and a slide portion 160 to which a ball screw nut 188 screwed with the ball screw shaft 101 is attached. The slide portion 160 includes a circular tubular first rod 175, a second rod 176, and a third rod 177 whose ends in the −Z axis direction are connected by a tip bracket 190 (hereinafter, rods are collectively referred to as rods). 175,176,177). The wrist unit 30 shown in FIG. 1 is attached to the tip bracket 190. As a result, the motor 120 rotates and drives the ball screw shaft 101, so that the slide portion 160 moves along the Z-axis direction. With the movement of the slide portion 160 in the Z-axis direction, the plurality of rods 175, 176, 177 and the wrist unit 30 shown in FIG. 1 move along the Z-axis direction.

As shown in FIG. 1, the wrist unit 30 is attached to the lower end of the actuator 100 for the Z axis. The wrist unit 30 rotates in the R direction, for example. This rotation in the R direction is rotation around the Z axis. Further, the wrist unit 30 has a rotating portion 30a that can rotate in the B direction (around the X axis).

As shown in FIG. 1, the gripper 40 is rotatably attached to the rotating portion 30a of the wrist unit 30 in the T direction (around the Z axis). Therefore, the gripper 40 is arbitrarily moved and controlled in the three-dimensional space of the X-axis, the Y-axis, and the Z-axis by the actuator 10 for the X-axis, the actuator 20 for the Y-axis, and the actuator 100 for the Z-axis. , Rotated by the wrist unit 30 in the R, B, and T directions. Further, the gripper 40 has two claw portions 41 and 42 for gripping the article. By changing the distance between the two claws 41 and 42, the article can be gripped and the gripped article can be separated. The robot 1 operates, for example, as a transport robot that transports an article gripped by the gripper 40 to a desired position by various actuators.

(Structure of Actuator 100 for Z-axis)
Next, the configuration of the actuator 100 for the Z axis will be described in detail. As shown in FIG. 2, the actuator 100 has a base 180 on which various parts are installed, and a cover 181 attached to the base 180 to cover various parts. The base 180 and the cover 181 form a housing 50 of the actuator 100, and form a storage space for accommodating various parts of the actuator 100. As will be described later, the base 180 movably supports the accommodating portion 198 accommodating the urging portion 112 (FIGS. 3 and 4) and the slide portion 160 moving along the Z-axis direction. It includes a base body 199 and a housing 200 that movably supports a plurality of rods 175, 176, 177 along the Z-axis direction.

As shown in FIG. 3, the actuator 100 includes a drive mechanism 110 for rotationally driving the ball screw shaft 101 in a portion (upper part of the actuator 100) on the + Z axis direction side. As shown in FIGS. 5 and 6, the drive mechanism 110 urges the drive unit 111 that outputs the power for rotationally driving the ball screw shaft 101 (FIG. 3) and the ball screw shaft 101 in a predetermined rotational direction. It has an urging unit 112 and a speed increasing unit 113 that accelerates the rotation of the urging unit 112.

As shown in FIGS. 7 and 8, the drive unit 111 has a motor 120, a pulley 121 connected to the motor 120, and a fixture 122 for attaching the motor 120 to the speed increasing unit 113.

As shown in FIG. 9, the motor 120 is, for example, a stepping motor and has a rotor, a stator, an encoder, and the like. Power is supplied to the motor 120 from a power source via a cable of a cable unit (not shown). Further, the cable unit includes a cable for supplying electric power from the outside, input / output of a control signal, and the like to the motor 120, and a cable guide for protecting the cable. By supplying electric power to the motor 120, the rotor of the motor 120 rotates. The rotary motion of this rotor is output to the output shaft 123 extending along the Z-axis direction.

The pulley 121 is fixed to the output shaft 123 by a screw 124 screwed from the outside. As a result, the pulley 121 rotates together with the output shaft 123.

The fixture 122 is formed by bending, for example, a metal plate. The fixture 122 has a rectangular flat plate portion 122a fixed to the motor 120 by a screw 125, two upright portions 122b vertically erected from opposite sides of the flat plate portion 122a, and outside from the end side of the upright portion 122b. It has a flange portion 122c formed toward the surface. An opening 122d is formed in the center of the flat plate portion 122a. The pulley 121 is attached to the output shaft 123 of the motor 120 in a state of penetrating the opening 122d. As a result, the pulley 121 is accommodated in the space surrounded by the flat plate portion 122a, the two standing portions 122b, and the speed increasing portion 113 shown in FIG. Further, as shown in FIG. 9, two elongated holes 122e whose longitudinal direction faces the X-axis direction are formed in each of the two flange portions 122c side by side in the X-axis direction. As shown in FIGS. 7 and 8, the flange portion 122c is fixed by screwing a screw 126 inserted into the elongated hole 122e in a state of being in contact with the speed increasing portion 113. By setting the hole through which the screw 126 is inserted to be the elongated hole 122e in this way, the mounting position of the drive unit 111 with respect to the speed increasing portion 113 can be adjusted in the direction along the X-axis direction. As a result, the tension of the timing belt 166, which will be described later, is adjusted over the pulley 121.

As shown in FIGS. 7 and 8, the urging unit 112 is arranged in the direction of the + Z axis with respect to the driving unit 111. The urging portion 112 has a royal fern mechanism 127, a pulley 128 connected to the royal fern mechanism 127, and a mounting plate 129 for attaching the royal fern mechanism 127 to the speed increasing portion 113.

As shown in FIG. 10, the royal fern mechanism 127 includes a cylindrical outer cylinder portion 130, a first flange 131 attached to an end portion of the outer cylinder portion 130 on the −Z axis direction side, and + Z of the outer cylinder portion 130. A second flange 132 attached to the end on the axial direction is assembled to accommodate and hold various parts inside. Specifically, the herb mechanism 127 has a rotary shaft 133, a first spring 134, a partition plate 135, and a second spring 136 as various parts.

The outer cylinder portion 130 is arranged so that the penetrating direction of the cavity is along the Z-axis direction. A plurality of screw holes 130a are formed on the circumference at the end of the outer cylinder portion 130 on the −Z axis direction side. These screw holes 130a are for screwing the first flange 131. Similarly, a plurality of screw holes (not shown) are formed on the circumference at the end of the outer cylinder portion 130 on the + Z axis direction side. These screw holes are for screwing the second flange 132. Further, on the inner peripheral surface 130b of the outer cylinder portion 130, an L-shaped groove 130c is formed over the entire length along the Z-axis direction. The L-shaped groove 130c locks one end of the first spring 134 and the second spring 136, as will be described later.

As shown in FIG. 10, the first flange 131 is formed in a circular shape, and the screw 137 is passed through the through hole 131a formed on the circumference to the end portion of the outer cylinder portion 130 on the −Z axis direction side. It is screwed. A circular opening 131b is formed in the center of the first flange 131, and the first flange 131 has a bearing 138 that rotatably supports the rotating shaft 133 at the location where the opening 131b is formed. ..

The second flange 132 is formed in a circular shape, and a screw 139 is passed through a through hole 132a formed on the circumference and screwed to the end of the outer cylinder portion 130 on the + Z axis direction side. A circular opening 132b is formed in the center of the second flange 132, and a bearing 140 that rotatably supports the rotating shaft 133 is housed in the opening 132b.

As shown in FIG. 10, the rotary shaft 133 is a rod-shaped member having a circular cross section, and has a large diameter portion 133a formed in the central portion and a small diameter smaller than the large diameter portion 133a at both ends of the large diameter portion 133a. It has parts 133b and 133c. Further, in the large diameter portion 133a, a groove 133d formed by cutting out the outer peripheral surface is formed along the longitudinal direction. The rotary shaft 133 penetrates the outer cylinder portion 130, the small diameter portion 133b on the −Z axis direction side is fitted to the bearing 138 and rotatably supported, and the small diameter portion 133c on the + Z axis direction side is fitted to the bearing 140. It is rotatably supported.

As shown in FIGS. 11 and 12, the first spring 134 is formed by processing a metal strip-shaped material into a spiral shape. At the outer end of the first spring 134, a first hook portion 134a formed by bending is formed. The first hook portion 134a is inserted into the groove 130c of the outer cylinder portion 130 and locked. On the other hand, as shown in FIGS. 11 and 12, a second hook portion 134b formed by bending is formed at the inner end of the first spring 134. The second hook portion 134b abuts on the groove 133d of the rotating shaft 133 and is locked.

As shown in FIG. 10, the second spring 136 is arranged on the + Z direction side opposite to the first spring 134 with the partition plate 135 interposed therebetween. The second spring 136 has the same configuration as the first spring 134, and the first hooking portion 136a is inserted into the groove 130c of the outer cylinder portion 130 shown in FIG. 11 and locked. On the other hand, the second hooking portion 136b abuts on the groove 133d of the rotating shaft 133 and is locked.

In this way, the rotary shaft 133 is connected to the outer cylinder portion 130 via the first mainspring 134 and the second mainspring 136 arranged along the Z axis. As a result, when the rotation shaft 133 is rotated in the clockwise direction in the figure from the state shown in FIG. 11 in which the mainspring releases energy, energy is accumulated in the mainspring, and as shown in FIG. The band-shaped material that constitutes the mainspring is wound up and gathered in the center. When the external force acting on the rotating shaft 133 is removed from the state shown in FIG. 12, the mainspring gradually releases the stored energy while rotating the rotating shaft 133 counterclockwise in the figure. Eventually, the mainspring returns to the state in which the energy is released as shown in FIG.

As shown in FIG. 10, the mounting plate 129 is composed of a rectangular plate, and has an opening 129a through which the rotating shaft 133 is inserted, four through holes 129b arranged around the opening 129a, and a royal fern mechanism 127. There are four through holes 129c for mounting the above. The four through holes 129c are composed of elongated holes and are formed so that the longitudinal directions face the same direction. The mounting plate 129 is screwed to the first flange 131 by a screw 141 that has passed through the through hole 129b. The mounting plate 129 is larger than the first flange 131, and a part thereof protrudes to the side of the royal fern mechanism 127 as shown in FIGS. 7 and 8. A through hole 129c is formed in this protruding portion. The royal fern mechanism 127 is screwed to the speed increasing portion 113 by a screw 142 inserted through the through hole 129c. By making the through hole 129c through which the screw 142 is inserted a long hole, the mounting position of the urging portion 112 with respect to the speed increasing portion 113 can be adjusted. As a result, the tension of the timing belt 152, which will be described later, is adjusted over the pulley 128. Further, the longitudinal direction of the through hole 129c is one with the direction in which the axis of the pulley 128 and the axis of the pulley 151 (FIGS. 13 and 14) to be described later to which the timing belt 152 is bridged are connected in the XY plane. I am doing it. However, it is optional to match both directions. Thereby, the tension of the timing belt 152 can be easily adjusted.

As shown in FIG. 10, the pulley 128 is connected to the rotary shaft 133 via the mounting member 143. The mounting member 143 is fixed to the small diameter portion 133b of the rotating shaft 133 by a screw 144. The pulley 128 is fixed to the mounting member 143 by a screw 145. As a result, the pulley 128 rotates about the Z axis together with the rotation axis 133.

As shown in FIGS. 5 and 6, the speed increasing unit 113 is provided between the driving unit 111 and the urging unit 112 arranged in the Z-axis direction. The speed increasing unit 113 transmits the motion output by the drive unit 111 to the ball screw shaft 101 shown in FIG. 3, and accelerates the rotational motion of the rotating shaft 133 output by the urging unit 112 to the ball screw shaft 101. introduce. As shown in FIGS. 7 and 8, the speed increasing unit 113 has a first plate 146, a second plate 147, and a third plate 148 arranged at intervals in the Z-axis direction. A spacing member 149, which is a rod-shaped member, is arranged between the first plate 146 and the second plate 147, so that the two are arranged at intervals in the Z-axis direction. Further, the interval holding member 150, which is a rod-shaped member, is arranged between the second plate 147 and the third plate 148, so that the two are arranged at intervals in the Z-axis direction. In this way, various parts of the speed-increasing portion 113 described below are attached to the three plates arranged at intervals in the Z-axis direction.

As shown in FIGS. 8 and 13, the first plate 146 is screwed to the spacing member 149 fixed to the second plate 147 with the screw 109 inserted. As shown in FIG. 8, the first plate 146 holds the urging portion 112 by attaching the mounting plate 129 from the + Z axis direction side by the screw 142. Further, the first plate 146 is formed with a notch 146a notched in a fan shape, whereby the pulley 128 of the urging portion 112 is arranged between the first plate 146 and the second plate 147 on the −Z axis direction side. can do. As shown in FIG. 14, between the first plate 146 and the second plate 147, in addition to the pulley 128, a pulley 151 having a diameter smaller than that of the pulley 128, and a timing of being bridged between the pulley 128 and the pulley 151. The belt 152 and the belt 152 are arranged. As a result, the rotational motion of the pulley 128 connected to the rotary shaft 133 is accelerated and transmitted to the pulley 151 via the timing belt 152.

As shown in FIG. 13, the second plate 147 is screwed to the space holding member 150 fixed to the third plate 148 with the screw 156 inserted. The second plate 147 has a through hole 147a for allowing the rotation shaft 154 to penetrate along the Z-axis direction and accommodating the bearing 162a on the + Z-axis direction side of the rotation shaft 154, and the + Z-axis direction side of the rotation shaft 161. A housing hole 147b for housing the bearing 161a is formed. A pulley 151 is connected to the rotating shaft 154 that penetrates the through hole 147a by a screw 153. As a result, the rotary motion of the pulley 151 is transmitted to the rotary shaft 154. Further, as shown in FIG. 15, between the second plate 147 and the third plate 148, a pulley 155 to which the rotating shaft 154 is connected and a pulley having a smaller diameter than the pulley 155 and to which the rotating shaft 161 is connected are connected. It has a 158, a timing belt 157 bridged between the pulley 155 and the pulley 158, and an idler 159 that contacts and guides the timing belt 157. The rotational motion of the pulley 155 connected to the rotary shaft 154 is accelerated and transmitted to the pulley 158 via the timing belt 157.

As shown in FIG. 13, the third plate 148 has the spacing member 150 fixed to the surface on the + Z axis direction side. The third plate 148 has an accommodating hole 148a for accommodating the bearing 162b on the −Z axis direction side of the rotating shaft 154, and an accommodating hole 148b for accommodating the bearing 161b on the −Z axis direction side of the rotating shaft 161. Is formed. The rotating shaft 161 penetrates the accommodating hole 148b formed in the third plate 148 and projects in the −Z axis direction. A pulley 164 and a shaft joint 165 are attached to a portion of the rotary shaft 161 projecting in the −Z axis direction.

The pulley 164 is fixed to the rotating shaft 161 by a screw 119 screwed from the outer peripheral surface. Further, as shown in FIG. 16, a timing belt 166 bridged between the pulley 164 and the pulley 121 of the drive unit 111 is arranged on the −Z axis direction side of the third plate 148. The timing belt 166 is arranged in a direction orthogonal to the output shaft 123 of the motor. The pulley 121 and the pulley 164 of the drive unit 111 have the same diameter. As a result, the rotational motion output by the drive unit 111 is transmitted to the pulley 164 via the timing belt 166.

As shown in FIG. 13, the shaft joint 165 is attached to the rotary shaft 161 by a screw 167 screwed from the outer peripheral surface. As shown in FIG. 17, the shaft joint 165 is connected to the shaft joint 168 provided at the end of the connecting shaft 169 on the + Z axis direction side. As a result, the rotational motion of the rotary shaft 161 (FIG. 13) is transmitted to the connecting shaft 169.

As shown in FIG. 17, the connecting shaft 169 is a rotating shaft extending along the Z-axis direction, and a screw 172 in which a small diameter portion 101b of the ball screw shaft 101 is screwed from the outer peripheral surface at an end portion on the −Z axis direction side. Is fixed by.

As shown in FIG. 17, the ball screw shaft 101 has a ball screw shaft main body 101a in which a spiral screw is formed on the outer peripheral surface and a small diameter portion 101b formed at the end of the ball screw shaft main body 101a on the + Z direction side. And have. Further, as shown in FIG. 18, the ball screw shaft 101 further has a small diameter portion 101c formed at an end portion on the −Z direction side and a steady rest member 102 fitted in the small diameter portion 101c. As shown in FIGS. 3 and 18, the ball screw shaft 101 is arranged so that the axis A coincides with the first rod 175 having a hole 175a formed in the center, and at least a part thereof in the length direction is a circular tube. It is arranged in a state of being inserted into the first rod 175 of the above. The diameter of the small diameter portions 101b and 101c is smaller than that of the ball screw shaft main body 101a. As described above, since the small diameter portion 101b is connected to the connecting shaft 169, the ball screw shaft 101 rotates around the Z axis as the connecting shaft 169 rotates.

As shown in FIG. 18, the steady rest member 102 has a ring-shaped steady rest member main body 102a having a groove 102b formed on an outer peripheral surface thereof, and an elastic member 102c housed in the groove 102b. The ball screw shaft 101 is inserted into the hole 175a formed in the first rod 175 in a state where the steady rest member main body 102a is fitted in the small diameter portion 101c. The elastic member 102c is, for example, an O-ring made of fluororubber. The diameter of the elastic member 102c in the cross section is larger than the depth of the groove 102b. Therefore, the elastic member 102c protrudes from the outer peripheral surface of the steady rest member main body 102a and elastically deforms to come into contact with the inner peripheral surface of the first rod 175. This makes it possible to suppress the runout of the first rod 175 that moves in the Z-axis direction.

As shown in FIG. 17, the bearing housing 170 has a through hole 170a along the Z-axis direction and is fixed to the base 180. The through hole 170a accommodates a part of the ball screw shaft 101 on the + Z axis direction side and a part of the connecting shaft 169 connected to the ball screw shaft 101 on the −Z axis direction side. On the other hand, the connecting shaft 169 has a portion protruding in the + Z axis direction from the end portion of the bearing housing 170. Further, the bearing housing 170 has a bearing 171 in the through hole 170a. The bearing 171 rotatably supports the vicinity of the end portion of the ball screw shaft 101 on the + Z axis direction side. Further, a brake 173 is screwed to the end of the bearing housing 170 on the + Z axis direction side by a screw 174.

The brake 173 is, for example, a non-excitation actuated brake in which the brake is applied when the energization is cut off, and an opening for penetrating the connecting shaft 169 is formed in the center. The brake 173 is provided between the disc-shaped plate 173a, the disc-shaped rotor 173b holding the connecting shaft 169, the stator 173c provided with springs and coils (not shown), and the rotor 173b and the stator 173c. It is equipped with a disc-shaped armature 173d. A spring (not shown) provided on the stator 173c exerts a force that pushes the armature 173d up in the + Z axis direction. When the energization of the brake 173 is cut off, the armature 173d pushed up by a spring (not shown) sandwiches the rotor 173b with the plate 173a. As a result, it is possible to stop the rotation of the connecting shaft 169 or maintain the stopped state of the connecting shaft 169 while the energization is cut off. On the other hand, when the brake 173 is energized, a coil (not shown) provided on the stator 173c attracts the armature 173d to the stator 173c side (-Z axis direction side), and the rotor 173b without being pinched by the armature becomes rotatable.

As shown in FIG. 2, the slide portion 160 is attached with the ends of the first rod 175, the second rod 176, and the third rod 177 on the + Z axis direction side, respectively. The slide portion 160 moves along the Z-axis direction together with these rods 175, 176, and 177. As shown in FIG. 19, the slide portion 160 includes a first holding portion 186, a second holding portion 187 overlapping the surface of the first holding portion 186 on the + X direction side, and wirings 214 and 216 arranged in the Y-axis direction. A first wiring fixture 182 for fixing (FIG. 2), a second wiring fixture 183 for fixing wirings 215 and 217 (FIG. 2) arranged in the Y-axis direction, and a first holding portion 186. It includes wiring retainers 184a, 184b, 185a, and 185b attached to the corners, respectively. The wirings 214, 215, 216, and 217 include power lines and signal lines.

As shown in FIG. 19, the first holding portion 186 is formed with a through hole 186a penetrating in the Z-axis direction. A female thread 186b is formed on the inner peripheral surface of the through hole 186a on the −Z axis direction side. A male screw 175b formed at the end of the first rod 175 on the + Z direction side shown in FIG. 3 is screwed into the female screw 186b. As a result, the first holding portion 186 holds the end portion of the first rod 175 on the + Z direction side. Further, as shown in FIGS. 3 and 17, a ball screw nut 188 is provided on the + Z axis direction side in the through hole 186a. As described above, the first holding portion 186 has a function as a nut holder for holding the ball screw nut 188. As shown in FIG. 17, the ball screw nut 188 is screwed into the ball screw shaft main body 101a, and a ball screw portion is formed on the inner peripheral surface thereof. The ball screw nut 188 is fitted into the ball screw shaft main body 101a via a metal sphere. As a result, the rotational movement of the ball screw shaft 101 is converted into a linear motion of the ball screw nut 188, and the first holding portion 186 holding the ball screw nut 188 makes a linear motion. The first rod 175 is directly attached to the first holding portion 186 that holds the ball screw nut 188 with the ball screw shaft 101 and the axis aligned with each other. Therefore, the force converted into linear motion between the ball screw shaft 101 and the ball screw nut 188 is directly transmitted to the first rod 175. For this reason, the first rod 175 functions as a main rod for moving the tip bracket 190 to which the wrist unit 30 and the like shown in FIG. 1 are attached up and down.

As shown in FIG. 19, through holes 187a and 187c penetrating in the Z-axis direction are formed in the second holding portion 187 side by side in the Y-axis direction. Female threads 187b and 187d are formed on the inner peripheral surfaces of the through holes 187a and 187c on the −Z axis direction side, respectively. As shown in FIG. 20, a male screw 177a formed at the end of the third rod 177 on the + Z direction side is screwed into the female screw 187d. As a result, the second holding portion 187 holds the end portion of the third rod 177 on the + Z direction side, and the through hole 187c and the through hole 177b formed in the third rod 177 are connected to each other. Similarly, a male screw (not shown) formed at the end of the second rod 176 on the + Z direction side shown in FIG. 3 is screwed into the female screw 187b shown in FIG. As a result, the second holding portion 187 holds the end portion of the second rod 176 on the + Z direction side. As a result, the through hole 187a formed in the second holding portion 187 shown in FIG. 19 and the through hole (not shown) of the second rod 176 are connected. The second holding portion 187 is shorter in the Z-axis direction than the first holding portion 186 because it does not have a ball screw nut, and is second to hold the second rod 176 and the third rod 177. 1 Functions as a rod bracket overlapped with the holding portion 186. Therefore, the axes of the second rod 176 and the third rod 177 do not match the ball screw shaft 101, and the force converted into linear motion between the ball screw shaft 101 and the ball screw nut 188 is the second force. It is indirectly transmitted to the second rod 176 and the third rod 177 via the holding portion 187. Therefore, the second rod 176 and the third rod 177 function as auxiliary rods to assist the first rod 175 when the tip bracket 190 to which the wrist unit 30 and the like shown in FIG. 1 are attached is moved up and down.

As described above, when the rods 175, 176, 177 held by the first holding portion 186 and the second holding portion 187 are viewed from the −Z axis direction, as shown in FIG. 22, the first rod 175 to the second rod 176 Is equal to the distance from the first rod 175 to the third rod 177. That is, the rods 175, 176, and 177 are arranged so that their centers are located at the positions of the vertices of the isosceles triangle. That is, the rods 175, 176, and 177 are arranged so as not to be biased in the housing 50.

As shown in FIG. 22, the first wiring fixture 182 has a first fixing portion 182a and a second fixing portion 182b arranged in the Y-axis direction in which the wiring is sandwiched and the intermediate portion is fixed. The first fixing portion 182a fixes the intermediate portion of the wiring 216 provided on the + Y side, and the second fixing portion 182b fixes the intermediate portion of the wiring 214 provided on the −Y side.

As shown in FIG. 19, the second wiring fixture 183 has a first fixing portion 183a and a second fixing portion 183b arranged in the Y-axis direction in which the wiring is sandwiched and the intermediate portion is fixed. The first fixing portion 183a fixes the intermediate portion of the wiring 217 provided on the + Y side, and the second fixing portion 183b fixes the intermediate portion of the wiring 215 provided on the −Y side.

The wiring holding portion 184a is attached to the corner portion of the first holding portion 186 on the −Z axis direction side from the −Y axis direction via the screw 189, and protrudes from the first holding portion 186 in the −Z axis direction. It has a mounting member 191a extending in the −X-axis direction from the end, and a roller 192a provided at the tip of the mounting member 191a extending in the −X-axis direction. Further, a wiring holding portion 184b is attached to the first holding portion 186 at a corner portion on the + Z axis direction side from the −Y axis direction via a screw 189. The wiring presser portion 184b has the same configuration as the wiring presser portion 184a, and has a mounting member 191b and a roller 192b (FIG. 20).

A return 194a is installed between the portion of the mounting member 191a extending in the −X axis direction and the end surface of the first holding portion 186 in the −Z axis direction. Similarly, the return 194b is installed on the end face of the first holding portion 186 in the + Z axis direction. A groove 186c having a curved concave surface is formed along the Z-axis direction on the side surface of the first holding portion 186 facing the −Y-axis direction. Further, in the returns 194a and 194b, openings 194c and 194d leading to an inversion path (not shown) formed inside the returns 194a and 194b are formed at both ends of the groove 186c. Further, inside the first holding portion 186, a passage (not shown) extending in the Z-axis direction is formed, which is connected to the reversing path (not shown) of the returns 194a and 194b. These inversion paths (not shown) and passages (not shown) form part of the circulation path of the rolling ball 193. As a result, the ball 193 is arranged along the oval-shaped orbit T and rolls on the orbit T. Further, in the openings 194c and 194d, a scooping portion for introducing the ball 193 from the groove 186c to the reversing path (not shown) is formed.

As shown in FIG. 19, the roller 192a has a cylindrical body, and its rotation axis is directed to the Y axis. The roller 192a attached to the mounting member 191a has a part protruding from the mounting member 191a in the −Z axis direction and a part protruding from the mounting member 191a in the −X axis direction as shown in FIG. 22. Further, the roller 192b (FIG. 20) attached to the attachment member 191b also partially protrudes from the attachment member 191b.

The wiring presser portion 185a has the same configuration as the wiring presser portion 184a, only the mounting direction with respect to the first holding portion 186 is different as shown in FIG. That is, the wiring holding portion 185a includes a mounting member 195a and a roller 196a provided on the mounting member 195a. Further, the wiring presser portion 185b has the same configuration as the wiring presser portion 184b, only the mounting direction with respect to the first holding portion 186 is different. That is, the wiring holding portion 185b includes a mounting member 195b and a roller (not shown) provided on the mounting member 195a. Further, a return 197a is installed between the portion extending in the −X axis direction of the mounting member 195a and the end surface of the first holding portion 186 in the −Z axis direction, and extends in the −X axis direction of the mounting member 195b. A return (not shown) is installed between the portion and the end surface of the first holding portion 186 in the + Z axis direction. A groove (not shown) similar to the groove 186c on the side surface facing the −Y axis direction is also installed on the side surface of the first holding portion 186 facing the + Y axis direction along the Z axis direction. A reversal path (not shown) formed in a return 197a provided on the axial side and a return (not shown) provided on the + Z axis direction, and a groove on the side surface of the first holding portion 186 facing the + Y axis direction (not shown). A trajectory forming a circulation path for a plurality of balls that roll is formed by a passage (not shown) formed inside the first holding portion 186 and a passage extending in the Z-axis direction (not shown). As shown in FIG. 2, the slide portion 160 configured in this way is movably supported in the Z-axis direction by the base body 199 extending along the Z-axis direction.

As shown in FIG. 22, the base main body 199 has a bottom wall 201 whose longitudinal direction is the Z-axis direction (direction perpendicular to the drawing), and side walls 202 formed on the + Y side and −Y side of the bottom wall 201. It has 203. The base body 199 is formed, for example, by extrusion molding aluminum.

The bottom wall 201 is formed with a protrusion 201a extending in the longitudinal direction (Z direction) at the center in the lateral direction (Y direction), and extends in the Z-axis direction to the + Y side and −Y side of the protrusion 201a. The recesses 201b and 201c are formed. The recess 201b is formed over the entire length of the bottom wall 201, and is used as a space for laying the wiring 217 or the wiring 216 (FIG. 2) depending on the position in the Z direction. Further, the recess 201c is formed over the entire length of the bottom wall, and is used as a space for laying the wiring 215 or the wiring 214 depending on the position in the Z-axis direction.

Recesses 202a and 203a are formed on the −Y side surface of the side wall 202 and the + Y side surface of the side wall 203, respectively. Steel rails 206 and 207 formed in a substantially rectangular cuboid with the Z-axis direction as the longitudinal direction are attached to the recesses 202a and 203a. Grooves 206a and 207a are formed along the Z-axis direction on the −Y side surface of the steel rail 206 and the + Y side surface of the steel rail 207, respectively. The grooves 206a and 207a are formed so as to face each other, and the inner surface of the grooves 206a and 207a is configured as a substantially curved surface. Specifically, the inner surface of the groove 207a is formed on a curved surface that holds the ball 193 shown in FIG. Similarly, the inner surface of the groove 206a is formed as a curved surface for holding a ball (not shown) provided on the side surface of the first holding portion 186 facing the + Y axis direction.

As shown in FIG. 19, the base body 199 includes a plurality of balls 193 provided on the −Y axis direction side of the first holding portion 186 and a plurality of balls (not shown) provided on the + Y axis direction side. The slide portion 160 is attached via the above. When the slide portion 160 is attached to the base main body 199, between the groove 207a of the steel rail 207 of the base main body 199 shown in FIG. 22 and the groove 186c of the first holding portion 186 on the −Y axis direction side shown in FIG. A ball 193 connected in the Z-axis direction is sandwiched between the two. Similarly, a ball (not shown) connected in the Z-axis direction between the groove 206a of the steel rail 206 of the base body 199 shown in FIG. 22 and the groove (not shown) on the + Y-axis direction of the first holding portion 186 shown in FIG. (Not shown) is sandwiched. In this way, the ball, which is a rolling element connected in the Z-axis direction, is interposed between the slide portion 160 and the base body 199, so that the slide portion 160 is movably supported by the base body 199 along the Z-axis direction. ing.

As shown in FIG. 2, the housing 200 constitutes a part of the base 180 and is attached to the end portion of the base main body 199 on the −Z side. The housing 200 is formed, for example, by die casting. Further, as shown in FIG. 18, the housing 200 is formed with a through hole 200a for passing the first rod 175, and the bearing 208b whose axis is aligned with the center of the through hole 200a is the housing 200. It is press-fitted into the flange portion 208a integrally installed on the surface on the + Z axis direction side. The bearing 208b is, for example, an oilless bearing. As a result, the first rod 175 is movably supported in the Z-axis direction by the bearing 208b.

Further, as shown in FIG. 2, in the housing 200, a through hole 200b for passing the second rod 176 and a through hole 200c for passing the third rod 177 are formed side by side in the Y-axis direction. There is. As shown in FIG. 21, the bearing 210b whose axis is aligned with the center of the through hole 200c is press-fitted into the flange portion 210a integrally installed on the surface of the housing 200 on the + Z axis direction side. Similarly, as shown in FIG. 18, the bearing 209b whose axis is aligned with the center of the through hole 200b is press-fitted into the flange portion 209a integrally installed on the surface of the housing 200 on the + Z direction side. The bearings 209b and 210b are also, for example, oilless bearings. As a result, the second rod 176 and the third rod 177 are movably supported in the Z-axis direction by the bearings 209b and 210b, respectively.

As shown in FIG. 2, the tip bracket 190 is formed of a rectangular plate, and the ends of the rods 175, 176, and 177 on the −Z side are connected to each other. Of these, the first rod 175 and the tip bracket 190 are connected via a screwing member 211 as shown in FIG. The screw-in member 211 is a columnar member having a flange portion 211a on the −Z axis direction side, and a screw 211b is formed on the + Z axis direction side. The screw-in member 211 is inserted through the opening 190a of the counterbore-processed tip bracket 190, is formed on the inner peripheral surface of the first rod 175, and is therefore screwed into the screw 175c. As a result, the first rod 175 and the tip bracket 190 are connected.

As shown in FIG. 21, the third rod 177 is screwed from the outer periphery in a state where the ring-shaped flange 213 is fitted to the end portion on the −Z axis direction side. As a result, the flange 213 is fixed to the end of the third rod 177. A screw 218 is screwed into the flange 213 from the −Z axis direction side of the tip bracket 190 with the end portion on the −Z axis direction side in contact with the tip bracket 190. As a result, the tip bracket 190 is attached to the flange 213. Similarly, as shown in FIG. 18, the second rod 176 is also fixed to the tip bracket 190 with the flange 212 attached to the end portion on the −Z axis direction side.

Further, as shown in FIG. 2, the tip bracket 190 is formed with circular openings 190b and 190c at locations where the second rod 176 and the third rod 177 are attached. As shown in FIG. 21, the opening 190c is formed at a position centered on the through hole 177b of the circular tubular third rod 177. Similarly, the opening 190b is formed at a position centered on the through hole 176a (FIG. 22) of the second rod 176. As a result, the wiring passed through the inside of the second rod 176 and the third rod 177 can be taken out from the openings 190b and 190c formed in the tip bracket 190.

The actuator 100 has various wirings for operating the motor 120 and the brake 173 shown in FIG. 17, and wirings for the wrist unit 30 and the gripper 40 directly or indirectly held by the actuator 100 shown in FIG. It will be provided. The wiring is divided and laid in different places so that each bundle does not become thick.

Wiring 214, 215 shown in FIG. 2 provided on the −Y direction side of the actuator 100 extends from the actuator 20 for the Y axis as shown in FIG. 4, and is opened in the recess 201c (FIG. 22) of the base body 199. It is passed through the insertion hole 199a and inside the actuator 100. Of the wirings 214 and 215 passed through the insertion hole 199a, the wiring 214 is laid in the recess 201c (FIG. 22) formed in the base body 199 in the −Z axis direction, and then bent 180 degrees. As shown in FIG. 20, the intermediate portion is fixed to the first wiring fixture 182 provided on the slide portion 160. The wiring 214 extending from the first wiring fixture 182 is bent 180 degrees again and passed from the through hole 187c of the slide portion 160 to the through hole 177b of the third rod 177. The wiring 214 passed through the through hole 177b of the third rod 177 exits from the opening 190c formed in the tip bracket 190 as shown in FIG. 21, and the wrist unit 30 attached to the tip bracket 190 (FIG. 1). ) Will be extended. As described above, the actuator 100 is formed with a continuous passage for passing the wiring from the slide portion 160 through the third rod 177 and penetrating the tip bracket 190.

On the other hand, the wiring 215 is laid in the recess 201c (FIG. 22) formed in the base body 199 in the + Z axis direction, then bent 180 degrees, and is provided in the slide portion 160 as shown in FIG. The intermediate portion is fixed to the second wiring fixture 183. The wiring 215 extending from the second wiring fixture 183 was passed from the through hole 187c of the slide portion 160 to the through hole 177b of the third rod 177 together with the wiring 214, and was formed in the tip bracket 190 as shown in FIG. It extends outward from the opening 190c to the wrist unit 30 (FIG. 1) attached to the tip bracket 190. A part of the wiring 215 is branched in the middle to become wiring for operating the motor 120 and the brake 173.

Similarly, the wirings 216 and 217 shown in FIG. 2 provided on the + Y direction side of the actuator 100 also pass through the insertion hole (not shown) formed in the recess 201b (FIG. 22) of the base body 199 and enter the inside of the actuator 100. Be passed. As shown in FIG. 2, the wirings 216 and 217 follow the same route as the wirings 214 and 215, and are passed through the inside of the second rod 176 as shown in FIG. The wirings 214 and 215 passed through the inside of the second rod 176 go out from the tip bracket 190 and extend to the wrist unit 30 (FIG. 1) attached to the tip bracket 190. As described above, the actuator 100 is formed with a continuous passage for passing the wiring from the slide portion 160 through the second rod 176 and penetrating the tip bracket 190.

As described above, the second rod 176 and the third rod 177 form a path for passing the wiring for the wrist unit (FIG. 1) provided on the tip bracket 190.

(Operation of actuator 100 for Z axis)
Next, the specific operation of the actuator 100 for the Z axis will be described. The actuator 100 shown in FIG. 23 is arranged so that the + Z direction is upward and the −Z axis direction is downward. Although the second rod 176 is not shown in FIGS. 23 (a) to 23 (c), it is adjacent to the reference numeral of the third rod 177 because it is arranged at the same position on the back side of the third rod 177. The code of the second rod 176 is attached to the marked part in parentheses. Further, in order to understand the internal state of the actuator 100, the cover 181 (FIG. 2) is not shown in FIGS. 23 (a) to 23 (c).

The actuator 100 shown in FIG. 23A is in a state where the slide portion 160 is in the uppermost position in the movable range, and the rods 175, 176, and 177 are in the most retracted state. At this time, if power is not supplied to the actuator 100, the brake 173 shown in FIG. 17 is activated, and the state in which the rotation of the ball screw shaft 101 is stopped can be maintained. Further, as shown in FIG. 11, the royal fern mechanism 127 is in a state where all the energy is released, or a royal fern mechanism 127 is in a state where only a part of the total amount of energy that can be stored is stored.

When power is supplied to the actuator 100 from the state shown in FIG. 23 (a), the brake by the brake 173 (FIG. 17) is released. Then, when the output shaft 123 (FIG. 16) of the motor 120 rotates in the direction of moving the slide portion 160 downward (first output direction), the rotational motion is transmitted via the pulley 121 and the timing belt 166 shown in FIG. , Transmit to the pulley 164. As shown in FIG. 17, the rotational motion transmitted to the pulley 164 is transmitted to the ball screw shaft 101 located coaxially. As a result, the ball screw shaft 101 rotates in the first rotation direction, and the slide portion 160 supporting the ball screw nut 188 moves downward on the base body 199. As the slide portion 160 moves, the rod 175, 176, 177, one end of which is held by the slide portion 160, and the tip bracket 190 attached to the other end of the rod 175, 176, 177 move downward, and eventually. The state shown in FIG. 23 (b) is obtained. When the slide portion 160 moves downward in this way, as shown in FIGS. 23 (a) to 23 (b), the wiring 214 whose intermediate portion is fixed to the first wiring fixture 182 is in the −Z axis direction. It is pushed back to and laid on the base body 199. On the other hand, the wiring 215 whose intermediate portion is fixed to the second wiring fixture 183 is pulled in the −Z axis direction, and the wiring laid on the base main body 199 rises up. The state of FIG. 23B is a state in which the slide portion 160 is in the middle position within the range in which the slide portion 160 can move up and down.

As described above, as the actuator 100 moves the slide portion 160 downward, energy is stored in the royal fern mechanism 127 shown in FIG. 7. That is, the rotational motion output from the motor 120 is transmitted to the pulley 128 via the speed increasing portion 113. As a result, as shown in FIG. 10, the rotation shaft 133 of the mainspring mechanism 127 to which the pulley 128 is connected rotates and winds up the first mainspring 134 and the second mainspring 136. As a result, energy is gradually stored in the Zenmai mechanism 127. The energy stored in the royal fern mechanism 127 as described above causes the ball screw shaft 101 to act on the urging force for rotating in the second rotation direction. This second rotation direction is the rotation direction of the ball screw shaft 101 that moves the slide portion 160 upward.

When the output shaft 123 of the motor 120 is further rotated in the first output direction from the state shown in FIG. 23 (b), the slide portion 160 is eventually moved to the lowermost position in the movable range as shown in FIG. 23 (c). The rods 175, 176, and 177 are located in the most protruding state from the housing 50. In this way, even when the state changes from FIG. 23 (b) to FIG. 23 (c), the energy of the royal fern mechanism 127 is accumulated, and when the state is in the state of FIG. 23 (c), the royal fern mechanism 127 The maximum energy is stored in. In this way, the actuator 100 moves the slide portion 160 downward while winding up the royal fern mechanism 127 (while accumulating energy).

When the output shaft 123 (FIG. 16) of the motor 120 rotates in the direction (second output direction) for moving the slide portion 160 upward from the state shown in FIG. 23 (c), the ball screw shaft 101 rotates in the second rotation direction. The slide portion 160 moves upward on the base body 199. During this time, the ball screw shaft 101 is urged in the second rotation direction by the royal fern mechanism 127. That is, the motor 120 moves the slide portion 160 upward while being assisted by the urging force output by the royal fern mechanism 127. As a result, the rods 175, 176, and 177 are gradually retracted. Eventually, the actuator 100 is in the state shown in FIG. 23 (b), and by further operating the motor 120, the slide portion can be in the state of being positioned at the uppermost position as shown in FIG. 23 (c).

As shown in FIGS. 23 (c) to 23 (a), when the slide portion 160 moves upward in this way, the wiring 214 whose intermediate portion is fixed to the first wiring fixture 182 is in the + Z axis direction. The wiring that was pulled and laid on the base body 199 stands up. On the other hand, the wiring 215 whose intermediate portion is fixed to the second wiring fixture 183 is pushed back in the + Z axis direction and laid on the base main body 199. The wirings 216 and 217 behave in the same manner as the wirings 214 and 215 while the slide portion 160 moves.

As shown in FIG. 22, various wirings are laid in the recesses 201b and 201c of the base main body 199 adjacent to the slide portion 160, and are pulled or pushed by the movement of the slide portion 160 as described above. Moving. At this time, the various wirings laid on the base body 199 are pressed by the rollers 192a, 192b, 196a (the remaining one roller is not shown) provided at the corners of the slide portion 160, so that the movement of the various wirings is performed. Can be made constant without scattering. Further, by using rollers 192a, 192b, and 196a (the remaining one roller is not shown), the wirings 214, 215, 216, and 217 can be prevented from being damaged, and the slide portion 160 can be moved. Can be prevented from being disturbed.

The actuator 100 operating in this way can move the slide portion 160 to a desired position by controlling the rotation direction and the number of steps of the output shaft 123 of the motor 120.

(effect)
According to the above embodiment, the slide portion 160 and the tip bracket 190 are connected to each other by three rods 175, 176, 177 at intervals. As a result, the bending rigidity can be increased and the vibration during operation can be reduced as compared with the case where the rods are connected by only one rod 175, for example.

Further, when the rods 175, 176, 177 connecting the slide portion 160 and the tip bracket 190 are viewed from the −Z axis direction, the rods are arranged so that their centers are located at the vertices of the isosceles triangle. By arranging the rods 175, 176, and 177 so as not to be biased in the housing 50 in this way, the bending rigidity can be increased in any direction orthogonal to the Z axis (linear motion direction). .. This makes it possible to reduce vibration during operation.

Further, the wiring for the wrist unit 30 attached to the tip bracket 190 is passed through the hollow portions of the second rod 176 and the third rod 177, and the wrist unit is taken out from the openings 190b and 190c formed in the tip bracket 190. Leading to 30. This makes it possible to easily arrange the wiring of the actuator attached to the tip of the actuator 100.

Further, the slide portion 160 is provided with a first wiring fixture 182 and a second wiring fixture 183 for fixing an intermediate portion of wiring passing through the hollow portions of the second rod 176 and the third rod 177. As a result, the wiring can be linearly moved together with the slide portion 160, and the wiring does not hinder the movement of the slide portion 160.

Further, rollers 192a, 192b, and 196a (the remaining one roller is not shown) are provided at each corner of the slide portion 160. The wiring arranged in the actuator 100 moves and deforms while being pulled or pushed as the slide portion 160 moves. At this time, the wiring laid on the base main body 199 is pressed by the rollers 192a, 192b, 196a (the remaining one roller is not shown), so that the movement of the wiring can be made constant without being scattered. Further, by setting the portions for holding the wiring to rollers 192a, 192b, 196a (the remaining one roller is not shown), it is possible to prevent damage to the wiring and prevent the movement of the slide portion 160 from being hindered. can.

Further, a non-excitation actuated type brake 173 is provided in which a brake is applied to the ball screw shaft 101 when the energization of the actuator 100 is cut off. This makes it possible to prevent the rods 175, 176, 177 and the like from unintentionally moving downward due to gravity when the power of the actuator 100 is turned off or a power failure occurs.

Further, a ball, which is a rolling element connected in the Z-axis direction (moving direction of the slide portion 160), is interposed between the slide portion 160 and the base main body 199. This ball is sandwiched between grooves extending in the Z-axis direction, and when the slide portion 160 moves, it rolls along the Z-axis direction, which is the movement direction of the slide portion 160. In this way, the slide portion 160 can move linearly by the intervention of a rolling element that continuously rolls along a direction in which it can move. Therefore, the slide portion 160 resists a force acting from a direction different from its own moving direction, for example, a torque caused by the rotation of the motor, and the vibration is less likely to be transmitted to the rod. As a result, it is possible to suppress the occurrence of runout at the tip of the work shaft.

The present invention is not limited to the above embodiment, and various modifications and applications are possible. In the above embodiment, the slide portion 160 is provided with two rods, a second rod 176 and a third rod 177, as auxiliary rods in addition to the first rod 175 as one main rod. The number is arbitrary, and may be, for example, one or three or more. The arrangement of the rods is not limited to the arrangement in which the center is located at the apex of the isosceles triangle as described above. For example, if many auxiliary flanges are arranged, the auxiliary rods may be arranged on the circumference centering on the main rod. By arranging the rods without being biased in a predetermined direction in this way, it is possible to increase the bending rigidity in various directions orthogonal to the axis of the rod. Further, as a special shape of an isosceles triangle, three rods may be arranged so that the center is located at the apex of the equilateral triangle. As a result, it is possible to realize an even arrangement of rods.

Further, in the above embodiment, the wiring is arranged on all of the two auxiliary rods, but it is not necessary to arrange the wiring on all of the auxiliary rods, and the wiring may be arranged only on a part of the auxiliary rods. Further, not only wiring but also piping such as air piping can be similarly installed in the above-mentioned wiring path.

Further, although it has been described that the rod has a circular tubular shape, the cross-sectional shape of the rod is arbitrary, and a rod made of a square tube may be adopted, or a rod having an elliptical cross-sectional shape may be adopted.

Further, although the robot 1 in which the moving direction of the rods 175, 176, 177 of the actuator 100 is the vertical direction is described, the direction in which the actuator 100 is installed is arbitrary, and the robot 1 is moved horizontally to the rods 175, 176, 177. The actuator 100 may be arranged in the.

Further, although the actuator 100 has been described as having a configuration in which the motor 120 is mounted inside, a configuration in which the motor can be attached and detached may be adopted, and the actuator itself may have a configuration in which the motor itself does not have a motor. In this case, the user may connect the output shaft of the attached motor and the ball screw by using a known transmission means.

1: Robot 10: Actuator 11: XY bracket 20: Actuator 21: YZ bracket 30: Wrist unit 30a: Rotating part 40: Gripper 41, 42: Claw part 50: Housing 100: Actuator 101: Ball screw shaft 101a: Ball screw Shaft main body 101b, 101c: Small diameter portion 102: Anti-sway member 102a: Anti-sway member main body 102b: Groove 102c: Elastic member 110: Drive mechanism 111: Drive unit 112: Energizing unit 113: Acceleration unit 120: Motor 121: Pulley 122: Mounting tool 122a: Flat plate portion 122b: Standing portion 122c, 211a: Flange portion 122e: Long hole 123: Output shaft 127: Spring mechanism 128: Pulley 129: Mounting plate 130: Outer cylinder portion 130b: Inner peripheral surface 130c: Groove 131: 1st flange 132: 2nd flange 133: Rotating shaft 133a: Large diameter portion 133b, 133c: Small diameter portion 133d: Groove 134: 1st screw spring 136: 2nd screw spring 134a, 136a: 1st hook portion 134b , 136b: 2nd hook 135: partition plate 138, 140: bearing 143: mounting member 146: 1st plate 146a: notch 147: 2nd plate 148: 3rd plate 149, 150: spacing member 151: pulley 152 , 157: Timing belt 154: Rotating shaft 155,158: Pulley 159: Idler 160: Slide part 161: Rotating shaft 162a, 162b: Bearing 164: Pulley 165, 168: Shaft joint 166: Timing belt 169: Connecting shaft 170: Bearing Housing 171: Bearing 173: Brake 175: 1st rod 175a: Hole 176: 2nd rod 177: 3rd rod 180: Base 181: Cover 182: 1st wiring fixture 182a, 183a: 1st fixing part 182b, 183b: Second fixing part 183: Second wiring fixture 184a, 184b, 185a, 185b: Wiring holding part 186: First holding part 187: Second holding part 188: Ball screw nut 190: Tip bracket 191a, 191b: Mounting member 192a , 192b, 196a: Roller 193: Ball 194a, 194b, 197a: Return 195a, 195b: Mounting member 198: Accommodating part 199: Base body 199a: Insertion hole 200: Housing 201: Bottom wall 201a: Protruding part 201b, 201c: Recessed part 202, 203: Side walls 202a, 203a: Recesses 214, 215, 216, 217: Wiring 206, 207: Steel rail 206 a, 207a: Grooves 208a, 209a, 210a: Flange portions 208b, 209b, 210b: Bearing 211: Screw-in member 212, 213: Flange

Claims (8)

A ball screw shaft that rotates by transmitting the rotational movement of the output shaft of the motor,
The ball screw nut provided on the ball screw shaft and
A slide portion having a first holding portion to which the ball screw nut is attached and a second holding portion overlapping the first holding portion and linearly moving with the rotational movement of the ball screw shaft.
A tubular first rod whose one end is held by the first holding portion,
A tubular second rod whose one end is held by the second holding portion,
A tip bracket for connecting the first rod and the second rod at the other end of each is provided.
The ball screw shaft penetrates the first holding portion, and one end thereof is rotatably supported by the inner peripheral surface of the first rod.
Actuator. The second holding portion is formed with a through hole connected to the hollow portion formed in the second rod.
The tip bracket is formed with an opening connected to the hollow portion formed in the second rod.
A passage is formed from the second holding portion through the second rod, penetrating the tip bracket, and passing wiring.
The actuator according to claim 1. The slide portion is provided with a wiring fixture for fixing an intermediate portion of wiring passing through the passage.
The actuator according to claim 2. Further, a tubular third rod having one end held by the second holding portion is further provided.
When viewed from the direction in which the slide portion moves linearly, the first rod, the second rod, and the third rod are arranged so that their respective centers are located at the vertices of an isosceles triangle.
The actuator according to any one of claims 1 to 3. The second holding portion is formed with a through hole connected to the hollow portion formed in the third rod.
The tip bracket is formed with an opening connected to the hollow portion formed in the third rod.
A passage is formed from the second holding portion through the third rod, penetrating the tip bracket, and passing wiring.
The actuator according to claim 4. Further provided with a base body that supports the slide portion so that it can move linearly,
A rolling element that rolls continuously along the moving direction of the slide portion is interposed between the slide portion and the base main body.
The actuator according to any one of claims 1 to 5. At one end of the ball screw shaft, a steady rest member that comes into contact with the inner peripheral surface of the first rod and suppresses the runout of the first rod is provided.
The actuator according to any one of claims 1 to 6. The actuator according to any one of claims 1 to 7, wherein a second actuator is attached to the tip bracket.
The wiring of the second actuator is guided from the tip bracket through at least the hollow portion of the second rod.
robot.

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