Robotic device

Abstract

To satisfactorily suppress deterioration in durability of a fluid actuator caused by occurrence of abnormality in a fluid supply device.SOLUTION: A robot device according to the disclosure includes at least one fluid actuator that receives supply of fluid to be activated and a fluid supply device that supplies the fluid actuator with fluid. The fluid supply device includes: a fluid supply source; a fluid adjustment part that adjusts pressure or flow volumes of fluid from the fluid supply source and supplies the fluid actuator with the fluid; an outflow regulating valve that regulates outflow of fluid from a fluid chamber of the fluid actuator in response to occurrence of an abnormality in the fluid supply device; and a relief part that makes fluid outflow from the fluid chamber of the fluid actuator in response to pressure increase of fluid in the fluid actuator in a period of time during which the fluid regulating vale regulates outflow of fluid from the flow chamber of the fluid actuator.SELECTED DRAWING: Figure 4

Description

Technical Field

[0003] , ,

[0001] The present disclosure relates to a robot device including at least one fluid actuator that operates upon receiving a fluid supply and a fluid supply device that supplies and discharges fluid to and from the fluid actuator.

Background Art

[0002] Conventionally, a manipulator arm is known that includes an upper arm member extending from a shoulder located on the upper part of a base, a forearm member attached to the tip of the upper arm member via an elbow joint, a flexible gripper attached to the tip of the forearm member and capable of gripping and releasing an object, a plurality of pneumatic actuators (artificial muscles) having rubber tubes that expand radially and contract axially in response to an increase in the pneumatic pressure supplied therein, and a safety device (see, for example, Patent Document 1). In this manipulator arm, the upper arm member performs a pitching operation by contracting one of a pair (two) of pneumatic actuators arranged on the side of the base and extending the other. Further, the forearm member performs a bending and stretching operation by contracting one of a pair (two) of pneumatic actuators arranged above or below the upper arm member and extending the other. Furthermore, the gripper performs a gripping and releasing operation by contracting one of a pair (two) of pneumatic actuators arranged above the forearm member and extending the other. Also, the safety device of the manipulator arm includes a pressure switch that detects that the pneumatic pressure supplied to each pneumatic actuator has dropped below a predetermined value, and a main block control valve and a plurality of block valves for confining the air in each pneumatic actuator within the pneumatic actuator when a drop in the pneumatic pressure is detected by the pressure switch. Thereby, when the air supplied to each pneumatic actuator decreases, it becomes possible to suppress the manipulator arm from collapsing and stretching due to its own weight or the gripper from dropping an object.

Prior Art Documents

Patent Documents

[0003] [[ID=2​[Patent Document 1] Japanese Utility Model Publication No. 05-22811 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] However, when the conventional manipulator arm described above is in operation, if air is trapped inside each pneumatic actuator by multiple block valves in response to a decrease in air pressure, the sudden increase in pressure inside the tube causes a momentary increase in the contraction force of one of the pneumatic actuators. For this reason, the manipulator arm described above requires an increase in the size and weight of the pneumatic actuators and other components to cope with the sudden increase in pressure inside the tube and the momentary increase in contraction force.

[0005] Therefore, the primary objective of this disclosure is to suppress the increase in size and weight of a robotic device used to respond to abnormalities in a fluid supply device that supplies fluid to a fluid actuator. [Means for solving the problem]

[0006] The robotic apparatus of the present disclosure includes at least one fluid actuator that operates in response to a fluid supply, and a fluid supply device that supplies and discharges the fluid to the fluid actuator, wherein the fluid supply device includes a fluid source, a fluid adjustment unit that adjusts the pressure or flow rate of the fluid from the source and supplies it to the fluid actuator, an outflow restriction valve that restricts the outflow of the fluid from the fluid actuator in response to an abnormality in the fluid supply device, and a relief unit that discharges the fluid from the fluid actuator in response to an increase in the pressure of the fluid in the fluid actuator while the outflow restriction valve restricts the outflow of the fluid from the fluid actuator.

[0007] In the robotic device of this disclosure, when a malfunction occurs in the fluid supply device, the outflow restriction valve restricts the outflow of fluid from the fluid actuator. Furthermore, while the outflow restriction valve restricts the outflow of fluid from the fluid actuator, the relief unit releases fluid from the fluid actuator in response to the increase in fluid pressure in the fluid actuator. As a result, even if the fluid actuator is pulled or pushed due to the inertia of the robotic device while the outflow of fluid from the fluid actuator is restricted by the outflow restriction valve, the relief unit releases fluid from the fluid actuator, thereby suppressing the increase in fluid pressure in the fluid actuator. Consequently, it is possible to suppress the increase in the size and weight of the fluid actuator and, consequently, the robotic device, in order to respond to a malfunction in the fluid supply device. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram showing the robotic device of this disclosure. [Figure 2] This is an enlarged view showing the robotic device of this disclosure. [Figure 3] This is a cross-sectional view showing the locking mechanism of the robot device disclosed herein. [Figure 4] This diagram shows the fluid supply system for the robotic device disclosed herein. [Figure 5] This is a partial cross-sectional view showing an outflow control valve included in the fluid supply device of a robotic apparatus of the present disclosure. [Figure 6] This is a partial cross-sectional view showing an outflow control valve included in the fluid supply device of a robotic apparatus of the present disclosure. [Figure 7] This is a partial cross-sectional view showing an outflow control valve included in the fluid supply device of a robotic apparatus of the present disclosure. [Figure 8] This is an enlarged view showing another fluid supply device for the robotic apparatus of this disclosure. [Figure 9] This is a schematic diagram illustrating other robotic devices in this disclosure. [Figure 10] This is a cross-sectional view showing a fluid actuator included in another robotic device of the present disclosure. [Figure 11] This is a diagram illustrating a fluid supply system for another robotic device in this disclosure. [Modes for carrying out the invention]

[0009] Next, with reference to the drawings, embodiments for carrying out the invention of this disclosure will be described.

[0010] Figure 1 is a schematic diagram showing the robot device 1 of this disclosure, and Figure 2 is an enlarged view showing the robot device 1. The robot device 1 shown in these drawings includes a robot arm 2 and a fluid supply device (liquid supply device) 10. In this embodiment, the robot device 1 is mounted on a transport cart 20 which is a so-called automated guided vehicle (AGV) or autonomous mobile robot (AMR) capable of self-propelling to a designated target position. However, the robot device 1 is not limited to being mounted on a transport cart 20, and may be fixed in a predetermined installation location.

[0011] The robot arm 2 is a multi-joint arm that includes a plurality of joints (pin joints) J1, J2, J3 (in this embodiment, three), a plurality of arms (links) 3 (in this embodiment, three), a plurality of fluid actuators (hydraulic actuators) M1, M2, M3, M4, M5, M6 as artificial muscles, provided in an even number (two in this embodiment) for each joint J1, J2, J3, and a hand portion (robot hand) 4 as a gripping portion (end-effector) attached to the arm 3 at the tip. The hand portion 4 of the robot arm 2 is controlled by the control device 100 (see Figure 4) of the robot device 1 to grip a target object (hereinafter referred to as "grasping target"). The fluid supply device 10 is also controlled by the control device 100 to supply and discharge hydraulic oil (liquid) as a fluid (working fluid) to each fluid actuator M1-M6. This allows the robot arm 2 to be driven hydraulically (hydraulic) to move the hand portion 4 to a desired position.

[0012] Each fluid actuator M1-M6 of the robot arm 2 is a so-called McKibben-type artificial muscle, as shown in Figure 2, and includes a tube T that defines a fluid chamber inside and expands due to the pressure of the hydraulic fluid supplied to the fluid chamber, and a braided sleeve S that covers the tube T. The tube T is formed in a cylindrical shape from an elastic material such as rubber with high oil resistance, and both ends of the tube T are sealed by sealing members C. An inlet and outlet IO for the hydraulic fluid is formed in the sealing member C on the base end side of the tube T (fluid supply device 10 side, lower end side in Figure 2). The braided sleeve S is formed in a cylindrical shape by braiding a plurality of cords oriented in a predetermined direction so that they intersect with each other, and is contractible in the axial and radial directions. As the cords forming the braided sleeve S, fiber cords, high-strength fibers, metal cords composed of ultrafine filaments, etc., can be used. By supplying hydraulic fluid from the inlet / outlet IO into the tube T of such fluid actuators M1-M6, and increasing the pressure of the hydraulic fluid inside the tube T, the tube T expands radially and contracts axially due to the action of the braided sleeve S, generating a contraction force corresponding to the pressure of the hydraulic fluid supplied to the internal fluid chamber.

[0013] As shown in Figures 1 and 2, of the multiple arms 3, the arm 3 closest to the base (closest to the fluid supply device 10) is rotatably supported by a support member 5 acting as a link via joint J1. In addition, two arms 3 are rotatably connected to each other via joints J2 or J3. Furthermore, connecting members 6 are fixed to the tips (end ends) of the two arms 3 on the fluid supply device 10 side. As shown in the figures, the support member 5 rotatably supports the sealing member C on the base end of the fluid actuator M1 corresponding to the base joint J1 via a first connecting shaft, and also rotatably supports the sealing member C on the base end of the fluid actuator M2 corresponding to the same joint J1 via a second connecting shaft.

[0014] Each connecting member 6 rotatably supports a sealing member C on the tip side (hand side) of a fluid actuator M1 or M3 corresponding to a joint J1 or J2 located on the proximal end side via a first connecting shaft, and rotatably supports a sealing member C on the tip side (hand side) of a fluid actuator M2 or M4 corresponding to the joint J1 or J2 via a second connecting shaft. Further, each connecting member 6 rotatably supports a sealing member C on the proximal end side of a fluid actuator M3 or M5 corresponding to a joint J2 or J3 located on the tip side via a first connecting shaft, and rotatably supports a sealing member C on the proximal end side of a fluid actuator M4 or M6 corresponding to the joint J2 or J3 via a second connecting shaft.

[0015] As a result, on both sides of each arm 3 extending from the joint axes of joints J1 - J3 toward the hand side (hand portion 4 side), two corresponding ones of the fluid actuators M1 - M6 are arranged in parallel with the arm 3. And the fluid actuators M1, M3, M5 arranged on one side of each arm 3 constitute a first artificial muscle (one of the antagonistic muscles) corresponding to one joint J1, J2 or J3, and the fluid actuators M2, M4, M6 arranged on the other side of each arm 3 constitute a second artificial muscle corresponding to one joint J1, J2 or J3 that pairs with the first artificial muscle.

[0016] However, the first and second artificial muscles may each be constituted by two or more (the same number) of fluid actuators, and the number of fluid actuators constituting the first artificial muscle and the number of fluid actuators constituting the second artificial muscle may be different. Further, in the present embodiment, a plurality (two) of fluid actuators M1, M2, etc. provided for one joint J1, J2 or J3 have the same specifications as each other, but the specifications of the fluid actuators constituting the first artificial muscle and the specifications of the fluid actuators constituting the second artificial muscle may be different.

[0017] Also, in the present embodiment, each arm 3 is formed hollow, and a plurality of hoses H (refer to the broken lines in FIG. 2), which serve as fluid supply pipes, are arranged inside each arm 3. Each hose H is connected to an inlet / outlet IO formed in a sealing member C on the proximal end side of the corresponding fluid actuator M1 - M6, and hydraulic oil (hydraulic pressure) from the fluid supply device 10 is supplied into the tubes T of the fluid actuators M1 - M6 via the hoses H.

[0018] Therefore, by controlling the fluid supply device 10 with the control device 100, the hydraulic pressure in the tube T of the fluid actuator M1 or the like that constitutes the first artificial muscle can be made different from the hydraulic pressure in the tube T of the fluid actuator M2 or the like that constitutes the second artificial muscle paired with the first artificial muscle. As a result, forces (rotational torques) can be transmitted from two fluid actuators M1, M2, etc., that are arranged to be antagonistic to each other, i.e., a pair of (one set of) the first and second artificial muscles, to each arm 3 via the connecting member 6, and each arm 3 can be rotated with respect to the support member 5 or the proximal - side arm 3 to change the joint angles of the joints J1 - J3. In the present embodiment, the fluid actuator M1 or the like that constitutes the first artificial muscle and the fluid actuator M2 or the like that constitutes the second artificial muscle paired with the first artificial muscle are driven by the hydraulic pressure from the fluid supply device 10 with the state where the tube T is axially contracted by a predetermined amount (for example, about 10% of the natural length) from the natural state as the initial state.

[0019] As shown in Figure 3, joint J1 of the robot device 1 includes a joint axis Ax and a bearing Br, which is held by the bearing holding portion 5a of the support member 5 and rotatably supports the joint axis Ax. One end of the joint axis Ax (right end in Figure 3) is fixed (connected) to the arm 3 (one of the two links) corresponding to joint J1 via a spline fitting portion. The other end of the joint axis Ax (left end in Figure 3) protrudes from the inner race of the bearing Br, which is held by the support member 5 (the other of the two links), on the opposite side from the arm 3. Similarly, the other joints J2 and J3 also include a joint axis (not shown) fixed to one of the two corresponding arms 3, and a bearing (not shown) held by the other of the two corresponding arms 3 and rotatably supports the joint axis.

[0020] Furthermore, as shown in Figure 1, the robot device 1 includes a plurality (three in this embodiment) of locking mechanisms 8 provided for each joint J1-J3. Each locking mechanism 8 receives hydraulic fluid from the fluid supply device 10 and restricts or allows the relative rotation of the two arms 3, etc., connected via the corresponding joints J1-J3, depending on the hydraulic fluid supply state from the fluid supply device 10. In this embodiment, the plurality of locking mechanisms 8 are so-called multi-plate clutch mechanisms having a common structure. Here, with reference to Figure 3, the configuration of the locking mechanism 8 will be described using the locking mechanism 8 corresponding to the most proximal joint J1 as an example. As shown in Figure 3, the locking mechanism 8 includes a hub member 81, a drum member 82, a plurality of friction plates (first friction engagement plates) 83, a plurality of separator plates 84 (second friction engagement plates) and a backing plate, a piston 85, and a plurality of springs (biasing members) 88.

[0021] The hub member 81 of the locking mechanism 8 includes a hub body 810 having a substantially cylindrical inner cylinder portion 811, an annular wall portion 812, and a substantially cylindrical outer cylinder portion 813, and an annular connecting piece 815 connected to the hub body 810. The inner cylinder portion 811 of the hub body 810 is formed in a bottomed cylindrical shape with one end open, and the annular wall portion 812 extends radially outward from the closed end of the inner cylinder portion 811. The outer cylinder portion 813 is formed to protrude axially on both sides from the outer circumference of the annular wall portion 812. Splines are formed on the outer circumferential surface of the outer cylinder portion 813, and the inner circumferences of a plurality of friction plates 83 (and backing plates) are fitted into these splines. Each friction plate 83 includes an annular plate and friction material attached to both sides of the plate. Furthermore, the connecting piece 815 of the hub member 81 is spline-fitted into one end (the right end in Figure 3) of the outer cylinder portion 813 of the hub body 810 and fixed to the hub body 810 using a snap ring. In addition, the other end of the articulation shaft Ax, which protrudes from the inner race of the bearing Br, is spline-fitted into the central hole of the connecting piece 815. As a result, the hub member 81 is fixed (connected) to the articulation shaft Ax (and the arm 3, which is one of the two links) so as to rotate together with the articulation shaft Ax, which rotates around the axis as the arm 3 rotates.

[0022] The drum member 82 of the locking mechanism 8 includes a substantially cylindrical drum body 820 and a cover 825 fixed to the drum body 820. A spline is formed on the inner circumferential surface of the drum body 820 of the drum member 82, and the outer circumferential portions of a plurality of separator plates 84 are fitted to this spline so as to be alternately arranged with a plurality of friction plates 83. Each separator plate 84 is an annular plate body with both sides formed smoothly. Furthermore, an annular flange portion 821 extending radially outward is formed at one end of the drum body 820, and this flange portion 821 is fixed to the support member 5 of the joint J1 via a plurality of bolts. In this way, the drum member 82 is fixed to the support member 5, which is the other of the two links.

[0023] The cover 825 of the drum member 82 includes a substantially cylindrical tubular portion 826 and an annular wall portion 827 extending radially inward from one end (the left end in Figure 3) of the tubular portion 826. The drum body 820 is fitted into the tubular portion 826 of the cover 825, and a sealing member such as an O-ring is placed between the inner circumferential surface of the tubular portion 826 and the drum body 820. The tubular portion 826 also has a plurality of fixing portions extending radially outward at circumferential intervals from the open end, and each fixing portion is fixed to the flange portion 821 of the drum body 820 via bolts. Furthermore, the inner circumferential portion of the annular wall portion 827 of the cover 825 rotatably supports the inner cylindrical portion 811 of the hub body 810 of the hub member 81, and a sealing member such as an O-ring is placed between the inner circumferential portion of the annular wall portion 827 and the inner cylindrical portion 811. As a result, the drum member 82, i.e., the drum body 820 and the cover 825, liquid-tightly surround the hub member 81 from the outside.

[0024] The piston 85 of the locking mechanism 8 includes an annular pressure-receiving portion 851, an annular plate-pressing portion 852 extending axially from the outer circumference of the pressure-receiving portion 851, and an annular projection 853 projecting radially inward from the pressure-receiving portion 851 in the same direction as the plate-pressing portion 852. The pressure-receiving portion 851 of the piston 85 is supported by the inner cylinder portion 811 of the hub body 810 of the hub member 81 so as to be axially slidable (movable) so as to be

[0025] Furthermore, a sealing member such as an O-ring is placed between the inner circumference of the pressure-receiving portion 851 and the inner cylinder portion 811. In addition, the protruding portion 853 of the piston 85 is slidably fitted into the other end (the left end in Figure 3) of the outer cylinder portion 813 of the hub body 810, and a sealing member such as an O-ring is placed between the protruding portion 853 and the inner circumference of the outer cylinder portion 813. As a result, the inner cylinder portion 811 and the annular wall portion 812 of the hub member 81, i.e., the hub body 810, and the pressure-receiving portion 851 and the protruding portion 853 of the piston 85 define the release fluid chamber 86 of the locking mechanism 8. The release fluid chamber 86 communicates with the internal space of the inner cylinder portion 811 to which hydraulic fluid, i.e., hydraulic pressure, is supplied from the fluid supply device 10, via a plurality of oil passage holes 811h formed in the inner cylinder portion 811 of the hub body 810.

[0026] In this embodiment, the multiple springs 88 of the locking mechanism 8 are all coil springs and are arranged circumferentially between the annular wall portion 827 of the cover 825 of the drum member 82 and the back surface of the piston 85. The multiple springs 88 bias the piston 85 to move away from the annular wall portion 827 of the cover 825. As a result, the locking mechanism 8 forms a locked state (the upper half state in Figure 3) when the thrust applied to the piston 85 by the action of hydraulic pressure in the release fluid chamber 86 is less than or equal to the biasing force of the multiple springs 88. In this locked state, the piston 85 is pressed by the multiple springs 88 and moves toward the hub member 81 side (right side in Figure 3), and the multiple friction plates 83 and separator plate 84 are pressed by the plate pressing portion 852 of the piston 85 and frictionally engage. As a result, the hub member 81, i.e., the arm 3, and the drum member 82, i.e., the support member 5, are integrally connected via multiple friction plates 83 and separator plates 84, and the relative rotation of the arm 3 and the support member 5 as two links is restricted.

[0027] Furthermore, the locking mechanism 8 forms an unlocked state (the lower half of the state in Figure 3) when the thrust applied to the piston 85 by the action of hydraulic pressure in the release fluid chamber 86 is greater than the biasing force of the multiple springs 88. In this unlocked state, the piston 85 moves toward the annular wall portion 827 side of the cover 825 (left side in Figure 3) against the biasing force of the multiple springs 88 due to the action of hydraulic pressure in the release fluid chamber 86, thereby releasing the frictional engagement of the multiple friction plates 83 and separator plate 84. As a result, the connection between the hub member 81, i.e., arm 3, and the drum member 82, i.e., support member 5, via the multiple friction plates 83 and separator plate 84 is released, and relative rotation of the arm 3 and support member 5 as two links is permitted. The biasing force of the multiple springs 88 is set to be lower than the thrust applied to the piston 85 by the action of the lowest pressure hydraulic pressure supplied from the fluid supply device 10. Alternatively, one or more elastic bodies such as disc springs or rubber may be used as biasing members instead of the multiple springs 88.

[0028] The fluid supply device 10 of the robot device 1, which supplies hydraulic fluid to the fluid actuators M1-M6 and each locking mechanism 8, etc., includes, as shown in Figure 1, a tank 11 that defines a hydraulic fluid reservoir (fluid reservoir) and a base 12 that rotatably supports the tank 11 around a rotation axis (see dashed line in Figure 1) that extends vertically. The tank 11 is, for example, a cylindrical body with its upper and lower ends closed, and capable of storing hydraulic fluid inside. In this embodiment, the support member 5 of the robot arm 2 is fixed to the upper wall portion 11u of the tank 11 via bolts (not shown) or the like so as to extend coaxially with the rotation axis of the tank 11 (see Figure 2). That is, the robot arm 2 is supported by the tank 11 (upper wall portion 11u) of the fluid supply device 10.

[0029] The base unit 12 is mounted (fixed) on the transport trolley 20 so as to be located below the robot arm 2 and the tank 11. The base unit 12 also supports a rotary drive unit (not shown) that rotates the tank 11 by a predetermined angle (e.g., 360°) around the rotation axis. By operating the rotary drive unit, the robot arm 2 can be rotated integrally with the tank 11 around the rotation axis. In this embodiment, the rotary drive unit is an oscillating motor driven by hydraulic pressure supplied from the fluid supply device 10. However, the rotary drive unit may also include an electric motor or a gear mechanism.

[0030] Furthermore, as shown in Figure 4, the fluid supply device 10 includes, in addition to the tank 11 and base 12, a pump 13 as a fluid supply source, a valve body (not shown) located inside the tank 11, a relief valve (pressure control valve) RV, a check valve CV, an accumulator 14, a plurality of linear solenoid valves 151, 152, 153, 154, 155, 156 as fluid adjustment valves (fluid adjustment section), an on / off solenoid valve 16 as a signal pressure output valve, a plurality of on / off valves (outflow control valves) 171, 172, 173, 174, 177, 176, and an electromagnetic switching valve 18.

[0031] Pump 13 is an electric pump controlled by the control device 100, which sucks in the hydraulic fluid stored in the tank 11 and discharges (pressure-feeds) it from the discharge port. In this embodiment, pump 13 includes a pump section located inside the tank 11 and a drive unit 130 located inside or outside the tank 11, which has a drive circuit such as an electric motor, a reduction gear mechanism, and an inverter controlled by the control device 100.

[0032] The relief valve RV limits the pressure of the hydraulic fluid discharged by the pump 13 so as not to exceed a predetermined upper limit pressure Plim (upper limit, in this embodiment, for example, about 6-7 MPa). The check valve CV allows the hydraulic fluid from the pump 13 (and relief valve RV) to flow out into the oil passage LL, and also restricts the flow of hydraulic fluid from the oil passage LL to the pump 13 (and relief valve RV). The accumulator 14 has an inlet and outlet for the hydraulic fluid connected (directly connected) to the oil passage LL downstream of the check valve CV, and stores the hydraulic pressure from the pump 13. Furthermore, the accumulator 14 used has a maximum operating pressure equal to or greater than the above upper limit pressure Plim. In addition, a source pressure sensor PS is installed in the oil passage LL downstream of the check valve CV and upstream of the accumulator 14 to detect the hydraulic fluid pressure (source pressure) in the oil passage LL.

[0033] Linear solenoid valves 151-156 have a common configuration and are each located within a valve body and controlled by the control device 100. In this embodiment, linear solenoid valve 151 adjusts the hydraulic pressure (drive pressure) to fluid actuator M1, and linear solenoid valve 152 adjusts the hydraulic pressure (drive pressure) to fluid actuator M2. Furthermore, linear solenoid valve 153 adjusts the hydraulic pressure (drive pressure) to fluid actuator M3, and linear solenoid valve 154 adjusts the hydraulic pressure (drive pressure) to fluid actuator M4. In addition, linear solenoid valve 155 adjusts the hydraulic pressure (drive pressure) to fluid actuator M5, and linear solenoid valve 156 adjusts the hydraulic pressure (drive pressure) to fluid actuator M6.

[0034] As shown in Figure 4, the linear solenoid valves 151-156 include an electromagnetic section 15e that is energized and controlled by the control device 100, a spool 15s that is axially movable within a sleeve held by the valve body, and a spring 15sp that biases the spool 15s toward the electromagnetic section 15e (from the output port 15o side to the input port 15i side, upper side in Figure 4). Furthermore, the linear solenoid valves 151-156 include an input port 15i, an output port 15o, a feedback port 15f that communicates with the output port 15o, and a drain port 15d that can communicate with the input port 15i and the output port 15o. The input port 15i of the linear solenoid valves 151-156 each communicates with the oil passage LL downstream of the accumulator 14. Furthermore, the drain ports 15d of the linear solenoid valves 151-156 are each connected to the hydraulic fluid reservoir in the tank 11 via the oil passage LD.

[0035] In this embodiment, the linear solenoid valves 151-156 are normally closed valves that open when current is supplied to the electromagnetic unit 15e. Each electromagnetic unit 15e moves the spool 15s axially in accordance with the applied current to connect the input port 15i and the output port 15o. This balances the thrust generated by the power supply to the electromagnetic unit 15e (coil), the biasing force of the spring 15sp, and the thrust acting on the spool 15s towards the electromagnetic unit 15e due to the hydraulic pressure (drive pressure) supplied from the output port 15o to the feedback port 15f. This makes it possible to adjust the hydraulic fluid from the pump 13 (and relief valve RV) supplied to the input port 15i to a desired pressure and discharge it from the output port 15o.

[0036] Furthermore, by feeding back the hydraulic pressure (drive pressure) supplied to the fluid actuators M1-M6 to the linear solenoid valves 151-156, when an external force other than that applied to the robot arm 2 driven by the fluid actuators M1-M6 (which act as artificial muscles) can be absorbed, the fluctuations in hydraulic pressure corresponding to the volume change of the tube T of the fluid actuators M1-M6 caused by the external force can be absorbed. In addition, after the external force has disappeared, it is possible to quickly supply the required hydraulic pressure (drive pressure) to the fluid actuators M1-M6.

[0037] The on / off solenoid valve 16 is a normally closed valve that includes an electromagnetic part 16e controlled by the control device 100, an input port 16i communicating with the output port of a modulator valve MV which acts as a pressure reducing valve to reduce the hydraulic pressure from the oil passage LL to a predetermined constant modulator pressure, and an output port 16o. The on / off solenoid valve 16 outputs a signal pressure by causing the hydraulic fluid from the modulator valve MV, which is supplied to the input port 16i in response to the energization of the electromagnetic part 16e, to flow out to the output port 16o.

[0038] The on / off valves 171-176 are normally closed spool valves that include a spool 17s located within the valve body and a spring 17sp that biases the spool 17s. As shown in Figure 4, the on / off valve 171 is located between the output port 15o of the linear solenoid valve 151 and the fluid actuator M1, and the on / off valve 172 is located between the output port 15o of the linear solenoid valve 152 and the fluid actuator M2. The on / off valve 173 is located between the output port 15o of the linear solenoid valve 153 and the fluid actuator M3, and the on / off valve 174 is located between the output port 15o of the linear solenoid valve 154 and the fluid actuator M4. Furthermore, the on / off valve 175 is located between the output port 15o of the linear solenoid valve 155 and the fluid actuator M5, and the on / off valve 176 is located between the output port 15o of the linear solenoid valve 156 and the fluid actuator M6.

[0039] As shown in Figure 5, the on / off valves 171-176 include an input port 17i, an output port 17o, and a signal pressure input port 17c, in addition to a spool 17s and a spring 17sp. The input port 17i communicates with the output port 15o of the corresponding linear solenoid valves 151-156 via an oil passage formed in the valve body. The output port 17o communicates with the inlet / outlet IO of the hydraulic fluid of the corresponding fluid actuators M1-M6 (tube T) via an oil passage or hose H formed in the valve body. The signal pressure input port 17c communicates with the output port 16o of the on / off solenoid valve 16 via an oil passage formed in the valve body.

[0040] Furthermore, in this embodiment, the signal pressure input port 17c of the on-off valves 171-176 is located on the opposite side of the spring chamber where the spring 17sp is located, and the output port 17o is located between the input port 17i and the signal pressure input port 17c in the axial direction of the spool 17s. The spool 17s of the on-off valves 171-176 includes a first land 17m having a pressure-receiving surface that receives the signal pressure supplied to the signal pressure input port 17c, a second land 17n that abuts against one end of the spring 17sp, and a shaft portion 17a having a smaller diameter than both that connects the first land 17m and the second land 17n. Furthermore, the spool 17s includes a hole 17h that extends axially from near the second land 17n and opens at the end face, i.e., the pressure-receiving surface, of the first land 17m, and a communication hole 17r that communicates with the hole 17h and extends radially from the spool 17s and opens at the outer circumferential surface of the shaft portion 17a. In addition, a pin 17p having a shorter axial length than the hole 17h is slidably positioned within the hole 17h of the spool 17s so as not to close the communication hole 17r.

[0041] When no signal pressure (modulator pressure) is supplied from the on / off solenoid valve 16 to the signal pressure input port 17c, the spool 17s of the on / off valve 171-176 is biased toward the signal pressure input port 17c side (upper in Figure 5) by the biasing force of the spring 17sp, causing the second land 17n to close the input port 17i and to block communication between the input port 17i and the output port 17o (see Figure 5). Hereinafter, the state in which the spool 17s closes the input port 17i and blocks communication between the input port 17i and the output port 17o will be referred to as the "outflow restriction state" of the on / off valve 171-176.

[0042] Furthermore, when no signal pressure is supplied from the on / off solenoid valve 16 to the signal pressure input port 17c, and the on / off valves 171-176 are in an outflow restriction state, the output port 17o communicates with the space between the first and second lands 17m and 17n, as shown in Figure 5, and also communicates with the hole 17h of the spool 17s via the communication hole 17r formed in the shaft portion 17a. In this embodiment, when no signal pressure is supplied from the on / off solenoid valve 16 to the signal pressure input port 17c, and the hydraulic fluid pressure in the output port 17o exceeds a threshold higher than the predetermined upper limit pressure Plim, the hydraulic thrust acting on the pressure-receiving surface of the second land 17n and the bottom surface (receiving surface) 17hb of the hole 17h of the spool 17s overcomes the biasing force of the spring 17sp. As a result, as shown in Figure 6, the spool 17s moves toward the spring chamber side (downward in Figure 6) against the biasing force of the spring 17sp, and the input port 17i and the output port 17o come into communication.

[0043] On the other hand, when a signal pressure from the on / off solenoid valve 16 is supplied to the signal pressure input port 17c in response to the energization of the electromagnetic unit 16e, the spool 17s of the on / off valves 171-176 is biased by the thrust based on the signal pressure, as shown in Figure 7, and moves toward the spring chamber side (downward in Figure 7) against the biasing force of the spring 17sp. As a result, the closure of the input port 17i by the second land 17n is released, and the input port 17i and the output port 17o are connected. As a result, the hydraulic pressure (drive pressure) from the linear solenoid valves 151-156 supplied to the input port 17i can be discharged from the output port 17o and supplied to the tube T of the fluid actuators M1-M6. Hereinafter, the state in which the spool 17s opens the input port 17i and connects the input port 17i and the output port 17o is referred to as the "connected state" of the on / off valves 171-176.

[0044] As shown in Figure 4, the switching valve 18 supplies and discharges hydraulic fluid to the locking mechanism 8 provided at the joints J1-J3 of the robot arm 2. The switching valve 18 is an electromagnetic spool valve and includes a sleeve disposed within the valve body, an electromagnetic part 18e controlled by the control device 100, a spool 18s slidably disposed within the sleeve, and a spring 18sp that biases the spool 18s toward the electromagnetic part 18e (from the output port 18o side to the input port 18i side, upper side in Figure 4). Furthermore, the switching valve 18 includes an input port 18i communicating with the oil passage LL, an output port 18o connected to the inner cylindrical portion 811 of the hub member 81 of each corresponding locking mechanism 8 via an oil passage formed in the valve body or a hose, plug, etc. (not shown), and a drain port 18d communicating with the hydraulic fluid reservoir in the tank 11 via the oil passage LD.

[0045] When the spool 18s of the switching valve 18 is not energized and no current is supplied to the electromagnetic part 18e, the biasing force of the spring 18sp causes the spool 18s to block communication between the input port 18i and the output port 18o, while simultaneously opening communication between the output port 18o and the drain port 18d. Hereinafter, the state in which the spool 18s blocks communication between the input port 18i and the output port 18o, while simultaneously opening communication between the output port 18o and the drain port 18d, is referred to as the "fluid discharge state" of the switching valve 18 (see dashed line in Figure 4). Furthermore, when the spool 18s of the switching valve 18 is energized and current is supplied to the electromagnetic part 18e, the thrust from the electromagnetic part 18e causes the spool 18s to open communication between the input port 18i and the output port 18o, against the biasing force of the spring 18sp. Hereinafter, the state in which the spool 18s connects the input port 18i and the output port 18o is referred to as the "fluid supply state" of the switching valve 18 (see solid line in Figure 4).

[0046] Furthermore, in this embodiment, an orifice Or, acting as a throttling member, is arranged in the oil passage connecting the output port 18o of the switching valve 18 and the inner cylindrical portion 811 of the hub member 81 of each locking mechanism 8, as shown in Figure 4. However, the orifice Or may be arranged in the oil passage connecting the drain port 18d of the switching valve 18 and the oil passage LD, as shown by the dashed line in the figure, so as to be close to the drain port 18d, or it may be arranged in both the oil passage connecting the switching valve 18 and the locking mechanism 8 and the oil passage connecting the drain port 18d and the oil passage LD. Also, the switching valve 18 may be replaced with an on-off solenoid valve that outputs a signal pressure and a spool valve (switching valve) that forms a fluid supply state in response to the supply of signal pressure from the on-off solenoid valve.

[0047] The control device 100 of the robot device 1 includes a microcomputer with a CPU, ROM, RAM, input / output interface, and various logic ICs (all not shown). The control device 100 receives detection values ​​from the source pressure sensor PS and a voltage sensor (not shown) that detects the voltage of the power supply for the linear solenoid valves 151-156, on / off solenoid valve 16, and switching valve 18. The control device 100 also controls the drive unit 130 of the pump 13 so that the oil pressure (source pressure) in the oil passage LL detected by the source pressure sensor PS becomes the target pressure. Furthermore, the control device 100 controls the current supplied to the electromagnetic parts 15e of the linear solenoid valves 151-156, the electromagnetic part 16e of the on / off solenoid valve 16, and the electromagnetic part 18e of the switching valve 18.

[0048] Furthermore, the control device 100 includes a plurality of current detection units (not shown) that detect the current flowing through the electromagnetic parts 15e of the linear solenoid valves 151-156, and monitors the current detected by each current detection unit. The control device 100 also monitors the detected values ​​from a plurality of pressure sensors (not shown) that detect the hydraulic pressure in each fluid actuator M1-M6, the rotational speed of the pump 13, the current supplied from the inverter of the drive unit 130 to the electric motor of the pump 13, etc. Based on these currents, pressures, rotational speeds, etc., the control device 100 determines whether or not there is an abnormality in the supply of hydraulic pressure to each fluid actuator M1-M6 (tube T).

[0049] Next, we will explain the operation of the robot device 1, which is configured as described above.

[0050] When the start switch (not shown) is turned off and the operation of the robot device 1 is completely stopped, the hand portion 4 is held by a locking portion formed on a support base (not shown) or the mounting surface of the robot device 1. In addition, the switching valve 18 of the fluid supply device 10 creates the fluid discharge state by cutting off the power supply to the electromagnetic portion 18e, and each locking mechanism 8 creates the locked state by the biasing force of multiple springs 88. As a result, the relative rotation of the arm 3, etc., as two links connected via joints J1-J3, is restricted, and the posture of the robot arm 2 is forcibly held in a predetermined standby posture.

[0051] Furthermore, once the start switch of the robot device 1 is turned on and system startup is complete, the control device 100 controls the pump 13 based on the detected value of the source pressure sensor PS so that the hydraulic pressure (source pressure) in the oil passage LL supplied to the linear solenoid valves 151-156 becomes a predetermined relatively low standby pressure Pst (in this embodiment, for example, about 1000 kPa). In this embodiment, the standby pressure Pst is set to a pressure that is a predetermined value higher than the pressure that can axially contract each of the multiple fluid actuators M1-M6 from their natural state to the initial state (for example, about 700-900 kPa). In addition, the control device 100 controls the current supplied to the electromagnetic unit 16e so that a signal pressure is output from the output port 16o of the on / off solenoid valve 16. As a result, each on-off valve 171-176 forms the above-mentioned communication state, and the input port 17i and output port 17o of each on-off valve 171-176 are connected, thereby allowing the supply of hydraulic fluid from the linear solenoid valve 151-156 to the fluid actuators M1-M6.

[0052] Next, the control device 100 controls the current to the electromagnetic parts 15e of the linear solenoid valves 151-156 so that the tubes T of the fluid actuators M1-M6 are filled with hydraulic fluid in a predetermined order and each tube T is brought to the initial state described above. As a result, hydraulic fluid is supplied to the tubes T of the fluid actuators M1-M6 from the corresponding linear solenoid valves 151-156, and each tube T contracts axially by a predetermined amount (for example, about 10% of its natural length) from its natural state. From this point onward, until the hand unit 4 is placed on the support base or the like and the operation of the robot device 1 is stopped, current is continuously supplied to each electromagnetic part 15e of the linear solenoid valves 151-156, and the linear solenoid valves 151-156 adjust the pressure of the hydraulic fluid from the pump 13 side according to the current supplied to the electromagnetic parts 15e.

[0053] After the robot device 1 has completed the preparations for starting work as described above, when instructed to start work using the robot arm 2 and hand unit 4, the control device 100 controls the pump 13 based on the value detected by the source pressure sensor PS so that the hydraulic pressure (source pressure) in the oil passage LL is lower than the upper limit pressure Plim and is set to a relatively high working pressure Pw (in this embodiment, for example, about 5-6 MPa) which is set to or above the minimum operating pressure of the accumulator 14. Furthermore, the control device 100 controls the current to the electromagnetic parts 15e of the linear solenoid valves 151-156 so that the hydraulic pressure required to hold the robot arm 2 in the above standby position without coercive force from each locking mechanism 8 is supplied to the tubes T of the fluid actuators M1-M6 in a predetermined order.

[0054] Furthermore, the control device 100 controls the current to the electromagnetic unit 18e so that the switching valve 18 forms the fluid supply state described above. As a result, hydraulic fluid from the oil passage LL is supplied to the release fluid chamber 86 of each locking mechanism 8 via the switching valve 18, and the action of the hydraulic pressure in the release fluid chamber 86 causes the piston 85 to move toward the annular wall portion 827 of the cover 825 against the biasing force of the multiple springs 88, thereby forming the unlocked state of each locking mechanism 8. As a result, the connection between the hub member 81, i.e., arm 3 and the drum member 82, i.e., support member 5 or other arm 3 via the multiple friction plates 83 and separator plate 84 is released, and relative rotation of the arms 3, etc., as two links connected via joints J1-J3 is permitted.

[0055] The control device 100 sets current command values ​​to each electromagnetic unit 15e so that hydraulic pressure corresponding to the robot arm 2 is supplied to each fluid actuator M1-M6 from the linear solenoid valves 151-156, and controls the current supplied to each electromagnetic unit 15e based on these current command values. As a result, the hydraulic pressure (drive pressure) adjusted by the linear solenoid valves 151-156 is supplied to the tube T of the fluid actuators M1-M6 via the on / off valves 171-176. Consequently, the multiple fluid actuators M1-M6 can rotate each arm 3, moving the hand unit 4 of the robot device 1 to the desired position.

[0056] On the other hand, if the power supply to the fluid supply device 10 is lost while the robot device 1 is operating, the power supply to each electromagnetic part 15e is cut off, so hydraulic fluid (hydraulic) is no longer supplied from the linear solenoid valves 151-156 to the fluid actuators M1-M6, and the force that restrains the joints J1-J3 by the multiple fluid actuators M1-M6 is lost. However, in this case, since the power supply to the electromagnetic part 16e of the on-off solenoid valve 16 is also cut off due to the power loss, the on-off solenoid valve 16, which is a normally closed valve, no signal pressure is output, and each on-off valve 171-176 forms the outflow restriction state described above.

[0057] As a result, when a power failure causes an abnormality (abnormal supply or abnormal stop) in the supply of hydraulic fluid from the linear solenoid valves 151-156 to the fluid actuators M1-M6, the hydraulic fluid that flows back from the tube T of the fluid actuators M1-M6 to the output port 17o of the on / off valves 171-176 is blocked by the second land 17n of the spool 17s, thereby restricting the outflow of the hydraulic fluid to the linear solenoid valves 151-156. In other words, the on / off solenoid valve 16 (electromagnetic part 16e) and the on / off valves 171-176 function as fluid retaining units that restrict the inflow and outflow of hydraulic fluid to the tube T of the fluid actuators M1-M6 in response to an abnormality in the supply of hydraulic fluid, thereby retaining the hydraulic fluid within the tube T.

[0058] Furthermore, a power outage also cuts off the power supply to the electromagnetic part 18e of the switching valve 18, causing the switching valve 18 to enter the fluid discharge state described above. This allows the hydraulic fluid in the release fluid chamber 86 of each locking mechanism 8 to be discharged into the hydraulic fluid reservoir in the tank 11 via the orifice Or, the output port 18o of the switching valve 18, the drain port 18d, and the oil passage LD. As the hydraulic fluid is discharged from the release fluid chamber 86, each locking mechanism 8 enters the locked state due to the biasing force of the multiple springs 88, restricting the relative rotation of the hub member 81 and the drum member 82, i.e., the arms 3 as two links connected via joints J1-J3.

[0059] As described above, in the robot device 1, when the supply of hydraulic fluid from the linear solenoid valves 151-156 to the tubes T of the fluid actuators M1-M6 is interrupted due to a power failure, the on / off valves 171-176 restrict the outflow of hydraulic fluid from each tube T, and the locking mechanisms 8 restrict the relative rotation of the two arms 3 corresponding to the joints J1-J3. Therefore, even if an abnormality occurs in the supply of hydraulic fluid from the linear solenoid valves 151-156 to the fluid actuators M1-M6, it is possible to suppress sudden changes in the state of the tubes T and effectively prevent the occurrence of unexpected movements of the robot arm 2, which is the driven object driven by the fluid actuators M1-M6. As a result, it is possible to further improve the stability and reliability of the operation of the robot device 1, which includes the fluid actuators M1-M6, acting as multiple artificial muscles that relatively rotate the two arms 3 connected via the joints J1-J3.

[0060] Furthermore, the fluid supply device 10 includes an orifice Or positioned in the oil passage (fluid passage) between each locking mechanism 8 and the switching valve 18. This suppresses the rapid discharge of hydraulic fluid from each locking mechanism 8 and makes it possible to restrict the relative rotation of the two arms 3 corresponding to joints J1-J3 without generating shocks from each locking mechanism 8. In this embodiment, the specifications of the orifice Or, such as the orifice diameter, are set so that each locking mechanism 8 forms a locked state after the outflow of hydraulic fluid from the fluid actuators M1-M6 is restricted by the on / off valves 171-176 in response to the occurrence of an abnormality, that is, after the spool 17s partially or completely closes the input port 17i.

[0061] Incidentally, when the outflow of hydraulic fluid from fluid actuators M1-M6 is restricted by the on / off valves 171-176 during the operation (movement) of the robot arm 2, the inertia of the arm 3 and hand 4, and the mass of the object being grasped, may cause one of the fluid actuators M1-M6 to be pulled or pushed, causing a rapid increase in the hydraulic fluid pressure in tube T. As a result, there is a risk that the durability of the fluid actuators M1-M6 and piping such as hose H may decrease due to abnormalities such as power failure.

[0062] Based on this, the robot device 1 provides a relief section with a hole 17h, a communication hole 17r, and a pin 17p for the spool 17s of each on-off valve 171-176. That is, while the on-off valves 171-176 restrict the outflow of hydraulic fluid from the corresponding tube T, if the relative rotation of the two arms 3 etc. causes the hydraulic fluid pressure at the output port 17o to exceed the threshold, this pressure propagates from the output port 17o through the communication hole 17r into the hole 17h of the spool 17s and acts on the bottom surface (receiving surface) 17hb of the hole 17h, causing the spool 17s to move toward the spring chamber side (downward in Figure 6) against the biasing force of the spring 17sp.

[0063] As a result, the closure of the input port 17i by the second land 17n is released, and the input port 17i and the output port 17o are connected. This allows the hydraulic fluid to flow from the tube T through the output port 17o to the input port 17i in response to a pressure increase (state change) in the hydraulic fluid in the fluid actuators M1-M6. Therefore, in the robot device 1, even if one of the tubes T of the fluid actuators M1-M6 is forcibly pulled or pushed in due to the inertia of the robot arm 2, etc., while the outflow of hydraulic fluid from the fluid actuators M1-M6 is restricted by the on / off valves 171-176, the rise in hydraulic pressure in the tube T can be suppressed. As a result, the decrease in the durability of the fluid actuators M1-M6 due to a malfunction of the fluid supply device 10 can be effectively suppressed, and the increase in the size and weight of the fluid actuators M1-M6 and the robot device 1 to suppress the decrease in durability caused by a malfunction of the fluid supply device 10 can be suppressed.

[0064] Furthermore, by providing a hole 17h with a bottom surface 17hb that serves as a receiving surface for the hydraulic fluid flowing from the tube T of the corresponding fluid actuator M1-M6 into the output port 17o in the spool 17s of the on / off valves 171-176, the on / off valves 171-176 can be made to function as a relief section, thereby making the fluid supply device 10 more compact. However, the configuration of the relief section of the on / off valves 171-176 is not limited to this. That is, for example, by making the outer diameter of the second land 17n larger than the outer diameter of the first land 17m, the input port 17i and the output port 17o may be connected against the biasing force of the spring 17sp in accordance with the hydraulic pressure acting on the second land 17n including the receiving surface when the supply of signal pressure from the on / off solenoid valve 16 is stopped.

[0065] Next, we will explain the operation of the robot device 1 when an abnormality occurs in the pump 13. As described above, when the control device 100 of the robot device 1 determines that an abnormality has occurred in the discharge of hydraulic fluid by the pump 13 based on the rotational speed of the pump 13 and the current supplied to the electric motor of the pump 13, it executes a predetermined fail-safe control for the pump 13 and stops the power supply to the electromagnetic part 16e of the on / off solenoid valve 16 and the electromagnetic part 18e of the switching valve 18. As a result, even if the power supply to the electromagnetic part 15e of the linear solenoid valves 151-156 continues, the on / off solenoid valve 16 will no longer output a signal pressure, and accordingly, each on / off valve 171-176 will form the outflow restriction state described above. In addition, the switching valve 18 will form the fluid discharge state described above in response to the cessation of power supply to the electromagnetic part 18e.

[0066] Here, some time is required between the detection of a malfunction in pump 13 and the formation of an outflow restriction state in each of the on / off valves 171-176. Also, if the hydraulic pressure (source pressure) in the oil passage LL supplied to each of the linear solenoid valves 151-156 decreases due to a malfunction in pump 13, the hydraulic pressure (drive pressure) supplied to the feedback port 15f decreases due to the pressure drop of the hydraulic fluid flowing out from the output port 15o. At the same time, thrust is continuously applied to the spool 15s from the electromagnetic part 15e, causing the spool 15s to move against the biasing force of the spring 15sp and connect the input port 15i and the output port 15o. Furthermore, if pump 13 stops due to a malfunction, the hydraulic pressure on the discharge side of pump 13 may become higher than the hydraulic pressure on the intake side, which may cause pump 13 to reverse. Therefore, if no countermeasures are taken, between the time a malfunction occurs in the pump 13 and the time when each on-off valve 171-176 forms an outflow restriction state, the hydraulic fluid in the tubes T of the fluid actuators M1-M6 may be sucked out by the pump 13, which is reversing direction, via the linear solenoid valves 151-156 (output port 15o and input port 15i), and the sudden change in the state of each tube T may cause unexpected movement of the robot arm 2.

[0067] Based on this, the fluid supply device 10 has a single check valve CV installed between a single pump 13 and a plurality of linear solenoid valves 151-156 provided for each of the plurality of fluid actuators M1-M6. The check valve CV restricts the flow of hydraulic fluid from each of the linear solenoid valves 151-156 to the pump 13. Therefore, even if the pump 13 stops due to some malfunction and hydraulic fluid is no longer supplied to the fluid actuators M1-M6 from the linear solenoid valves 151-156 to which current is supplied to the electromagnetic part 15e, the check valve CV can prevent hydraulic fluid from flowing out of the tubes T of each fluid actuator M1-M6 to the linear solenoid valves 151-156 and the pump 13 from the time the malfunction of the pump 13 occurs until the on / off valve 171-176 restricts the outflow of hydraulic fluid from the fluid actuators M1-M6. As a result, even if some abnormality occurs in the supply of hydraulic fluid to the fluid actuators M1-M6, it is possible to suppress sudden changes in the state of tube T and effectively prevent unexpected movements of the robot device 1 (robot arm 2), including the fluid actuators M1-M6.

[0068] Furthermore, in the robot device 1, if any abnormality occurs in the supply of hydraulic fluid to the fluid actuators M1-M6, a single check valve CV can suppress a sudden change in the state of multiple fluid actuators M1-M6 (tube T), thereby suppressing cost increases for the fluid supply device 10 and, consequently, the robot device 1. However, in the fluid supply device 10, one check valve CV may be placed between the input port 15i and the pump 13 for each of the multiple linear solenoid valves 151-156.

[0069] Furthermore, the fluid supply device 10 includes an accumulator 14 connected to an oil passage (fluid passage) LL that connects the check valve CV and the fluid actuators M1-M6. That is, even if a check valve CV is provided between the pump 13 and the multiple linear solenoid valves 151-156, if hydraulic fluid continues to flow to any of the contracting fluid actuators M1-M6, the hydraulic pressure in the oil passage LL will drop sharply, which may cause a backflow of hydraulic fluid from the other fluid actuators and a sudden change in the state of the robot arm 2. In contrast, with the fluid supply device 10, since the accumulator 14 in the oil passage LL is connected, even if the pump 13 stops while the robot arm 2 is operating (moving), hydraulic fluid from the accumulator 14 can be supplied to the fluid actuators M1-M6 via the linear solenoid valves 151-156 for a while. As a result, it is possible to suppress sudden changes in the state of the fluid actuators M1-M6 (tube T).

[0070] Then, while the check valve CV (and accumulator 14) restricts the outflow of hydraulic fluid from the tube T of the fluid actuator M1-M6 to the oil passage LL side, when the on-off valves 171-176 form an outflow restriction state, the hydraulic fluid that has flowed back from the tube T of the fluid actuator M1-M6 to the output port 17o of the on-off valves 171-176 can be blocked by the second land 17n of the spool 17s from flowing out to the linear solenoid valve 151-156 side.

[0071] Furthermore, in the fluid supply device 10, an orifice Or is positioned between the output port 18o of the switching valve 18 and each locking mechanism 8. The orifice diameter of the orifice Or is set such that each locking mechanism 8 forms a locked state after the outflow of hydraulic fluid from the fluid actuators M1-M6 is restricted by the on / off valves 171-176. Therefore, even if the power supply to the electromagnetic part 18e is stopped and the switching valve 18 forms a fluid discharge state, hydraulic fluid will be discharged from each locking mechanism 8 relatively slowly. Consequently, even if the power supply to the on / off solenoid valve 16 and the switching valve 18 is released approximately simultaneously, each locking mechanism 8 will form a locked state after the outflow of hydraulic fluid from the fluid actuators M1-M6 is restricted by the on / off valves 171-176. In other words, the on / off valves 171-176 and each locking mechanism 8 are controlled by the control device 100 so that each locking mechanism 8 forms a locked state after the on / off valves 171-176 begin to restrict the outflow of hydraulic fluid from the fluid actuators M1-M6 in response to an abnormality in the pump 13.

[0072] As a result, in response to a malfunction in the pump 13, the on / off valves 171-176 restrict the outflow of hydraulic fluid from the fluid actuators M1-M6, suppressing abrupt changes in the state of tube T. At the same time, the robot arm 2, while in operation (moving), is braked by restricting the outflow of hydraulic fluid from the fluid actuators M1-M6. Furthermore, the locking mechanisms 8 restrict the relative rotation of the two arms 3, etc., without generating shocks, thereby suppressing the occurrence of unexpected movements of the robot arm 2, i.e., the robot device 1. As a result, the stability and reliability of the operation of the robot device 1 in the event of a malfunction in the pump 13 can be further improved. Moreover, since the need to improve the strength of the arms 3, etc., is reduced by suppressing the occurrence of shocks, the overall size and weight of the robot device 1 can be suppressed. Furthermore, with the fluid supply device 10 including the orifice Or as described above, even if a de-energization command (operation command) is given to the on / off solenoid valve 16 (on / off valves 171-176) and the switching valve 18 (each locking mechanism 8) almost simultaneously in response to the occurrence (detection) of a malfunction in the pump 13, the locking mechanism 8 can be made to enter a locked state after the outflow of hydraulic fluid from the fluid actuators M1-M6 has begun to be restricted by the on / off valve 171-176. This simplifies the control of the on / off valve 171-176 and each locking mechanism 8 (on / off solenoid valve 16 and switching valve 18) in the event of a malfunction in the pump 13, while suppressing the occurrence of unexpected movements of the robot arm 2, i.e., the robot device 1.

[0073] Furthermore, while the on / off valves 171-176 restrict the outflow of hydraulic fluid from the tubes T of the corresponding fluid actuators M1-M6 in response to a malfunction in the pump 13, if the hydraulic fluid pressure at the output port 17o exceeds the threshold due to the relative rotation of the two arms 3, etc., the on / off valves 171-176 allow the hydraulic fluid from the tubes T of the corresponding fluid actuators M1-M6 to flow out to the input port 17i. As a result, even if one of the tubes T of the fluid actuators M1-M6 is forcibly pulled or pushed in due to the inertia of the robot arm 2, etc., while the outflow of hydraulic fluid from the fluid actuators M1-M6 is restricted by the on / off valves 171-176, the rise in hydraulic pressure in the tube T can be suppressed. As a result, the decrease in the durability of the fluid actuators M1-M6 due to a malfunction in the fluid supply device 10 can be effectively suppressed, and the increase in the size and weight of the fluid actuators M1-M6 and, consequently, the robot device 1, in order to respond to a malfunction in the fluid supply device 10 can be suppressed.

[0074] Furthermore, the control device 100 of the robot device 1 stops the power supply to the electromagnetic part 16e of the on / off solenoid valve 16 and the electromagnetic part 18e of the switching valve 18 in response to the occurrence (detection) of at least one abnormality (including an abnormality in the drive circuit) of the linear solenoid valves 151-156. In addition, the control device 100 also stops the power supply to the electromagnetic part 16e of the on / off solenoid valve 16 and the electromagnetic part 18e of the switching valve 18 when it determines from the detected value of a hydraulic sensor (not shown) provided for each fluid actuator M1-M6 that an abnormality has occurred in the fluid actuator M1-M6.

[0075] In the above embodiment, the fluid actuators M1-M6 as artificial muscles are McKibben-type artificial muscles that define a fluid chamber to which hydraulic fluid is supplied and contract axially while expanding radially in response to an increase in hydraulic pressure in the fluid chamber, and a braided sleeve S that covers the tube T. However, the configuration of the fluid actuators M1-M6 in the robot device 1 is not limited to this. That is, the fluid actuators M1-M6 only need to include a tube that contracts axially while expanding radially when fluid is supplied, and may be, for example, an axial fiber-reinforced fluid actuator (see, for example, Japanese Patent Application Publication No. 2011-137516) that includes an inner cylindrical member formed of an elastic material, an outer cylindrical member formed of an elastic material and coaxially arranged outside the inner cylindrical member, and a fiber layer arranged between the inner cylindrical member and the outer cylindrical member.

[0076] Figure 8 is an enlarged view showing another fluid supply device 10B applicable to the robot device 1. In the fluid supply device 10B shown in the figure, an on / off valve (outflow control valve) 170 is positioned between the linear solenoid valves 151-156 and the corresponding fluid actuators M1-M6. The on / off valve 170 is equivalent to the on / off valves 171-176 with the relief portion hole 17h, communication hole 17r, and pin 17p omitted. Also, similar to the on / off valves 171-176, the on / off valve 170 includes an input port 17i that communicates with the output port 15o of the linear solenoid valves 151-156, an output port 17o that communicates with the hydraulic fluid inlet / outlet IO of the fluid actuators M1-M6 (tube T), and a signal pressure input port 17c that communicates with the output port 16o of the on / off solenoid valve 16.

[0077] Furthermore, as shown in Figure 8, the fluid supply device 10B includes a plurality of relief valves 19 positioned between the output ports 17o of each on-off valve 170 and the corresponding fluid actuators M1-M6. Each relief valve 19 includes a valve body 19v slidably disposed within a valve body, an inlet port 19i formed in the valve body to communicate with an oil passage connecting the on-off valve 170 and the corresponding fluid actuators M1-M6, an outlet port 19o formed in the valve body, and a spring 19sp that biases the valve body 19v so that one end of the valve body 19v closes the inlet port 19i and the outlet port 19o. When the pressure of the hydraulic fluid flowing into the inlet port 19i exceeds a predetermined opening pressure, the valve body 19v of the relief valve 19 moves against the biasing force of the spring 19sp to connect the inlet port 19i and the outlet port 19o. In the fluid supply device 10B, the opening pressure of each relief valve 19 is set to be higher than the maximum value of the hydraulic pressure (drive pressure) supplied from the linear solenoid valves 151-156 to the fluid actuators M1-M6 when the robot device 1 (robot arm 2) is operating.

[0078] In the fluid supply device 10B described above, the outflow of hydraulic fluid from the fluid actuators M1-M6 is restricted by each on-off valve 170 in response to power failure or malfunction of the pump 13, etc. Furthermore, when the two arms 3, etc., which are connected to each other, rotate relative to each other, if the outflow of hydraulic fluid from the fluid actuators M1-M6 is restricted by each on-off valve 170, at least one of the fluid actuators M1-M6 is pulled or pushed due to the inertia of the robot arm 2, causing a rapid increase in the pressure inside the tube T. At this time, the valve body 19v of the corresponding relief valve 19 moves against the biasing force of the spring 19sp, connecting the inlet port 19i and the outlet port 19o. In other words, each relief valve 19 releases hydraulic fluid from the tube T in response to the pressure increase (change in state) of the hydraulic fluid in the fluid actuator M1-M6 while each on-off valve 170 restricts the outflow of hydraulic fluid from the tube T of the corresponding fluid actuator M1-M6. This makes it possible to suppress the rise in hydraulic pressure within any of the tubes T of the fluid actuators M1-M6, even if they are forcibly pulled or pushed in. As a result, it is possible to effectively suppress the decrease in durability of the fluid actuators M1-M6 due to malfunctions in the fluid supply device 10B, and to suppress the increase in size and weight of the fluid actuators M1-M6 and, consequently, the robot device 1, in order to respond to malfunctions in the fluid supply device 10. In addition, by providing the fluid supply device 10B with multiple relief valves 19 as described above, the structure of the on / off valve 170 can be simplified.

[0079] Figure 9 is a schematic diagram showing another robot device 1C of the present disclosure. Note that, among the components of robot device 1C, elements identical to those of robot device 1 described above are denoted by the same reference numerals, and redundant explanations are omitted.

[0080] The robot device 1C shown in Figure 9 includes a robot arm 2C and a fluid supply device (liquid supply device) 10C that supplies and discharges fluid to a plurality (two in this embodiment) of double-acting cylinders (hydraulic cylinders) 7, which act as fluid actuators (hydraulic actuators) to operate the robot arm 2C. This robot device 1C is either mounted on a transport cart that is an automated guided vehicle (AGV) or an autonomous mobile robot (AMR) capable of self-propelling to a designated target location, or it is used by being fixed in a predetermined installation location. As shown in Figure 9, the robot arm 2C is a multi-joint arm that includes, in addition to multiple double-acting cylinders 7, a support member (bracket) 5, multiple arms (links) 3a, 3b, 3c, links 61, 62, 63, 64 that form first and second parallel link mechanisms through the cooperation of the multiple arms 3a, 3b, 3c, a hand part (robot hand) 4 as a gripping part (end-effector), and multiple (three in this embodiment) joints (pin joints) J1, J2, J3.

[0081] Each double-acting cylinder 7 of the robot arm 2C includes, as shown in Figure 10, a cylinder 70, a piston 74 slidably arranged axially within the cylinder (cylinder tube) 70, and a piston rod 75 fixed coaxially to the piston 74. Furthermore, each double-acting cylinder 7 includes a first fluid chamber (contraction side fluid chamber) 71 defined on one side (right side in Figure 10) of the piston 74 within the cylinder (cylinder tube) 70, and a second fluid chamber (extension side fluid chamber) 72 defined on the other side (left side in Figure 10) of the piston 74 within the cylinder 70. By supplying hydraulic fluid to the first fluid chamber 71 and discharging hydraulic fluid from the second fluid chamber 72 using the fluid supply device 10C, the piston 74 and piston rod 75 can be moved to the left side in Figure 10 relative to the cylinder 70, thereby extending the double-acting cylinder 7 as a double-acting actuator. Furthermore, by supplying hydraulic fluid to the second fluid chamber 72 and discharging hydraulic fluid from the first fluid chamber 71 using the fluid supply device 10C, the piston 74 and piston rod 75 can be moved to the right side in Figure 10 relative to the cylinder 70, thereby retracting the double-acting cylinder 7.

[0082] Arm 3a of robot arm 2C is rotatably connected to a support member 5 as a link via joint J1, and rotates relative to the support member 5 by the extension and retraction of a single double-acting cylinder 7. One end of the double-acting cylinder 7 corresponding to the support member 5 and arm 3a, i.e., joint J1, i.e., the end of the piston rod 75, is rotatably connected to a lever member fixed to the support member 5, and the other end, i.e., the end of the cylinder 70, is rotatably connected to the tip of arm 3a (the end on the arm 3b side). Arm 3b is also rotatably connected to arm 3a via joint J2, and rotates relative to arm 3a by the extension and retraction of a single double-acting cylinder 7. One end of the double-acting cylinder 7 corresponding to arms 3a and 3b, i.e., joint J2, i.e., the end of the piston rod 75, is rotatably connected to the base end of arm 3a (the end on the support member 5 side), and the other end, i.e., the end of the cylinder 70, is rotatably connected to a lever member fixed to the base end of arm 3b (the end on the arm 3a side). Furthermore, arm 3c is rotatably connected to the tip of arm 3b via joint J3. However, two double-acting cylinders 7 may be provided in parallel with respect to the support member 5 and arm 3a, or two double-acting cylinders 7 may be provided in parallel with respect to arms 3a and 3b.

[0083] Link 61 is fixed to the support member 5, and the base end of link 62 is rotatably connected to the tip of arm 3a and the base end of arm 3b via joint J2. Link 63 has the same link length as arm 3a and is rotatably connected to the free end (pivot portion) of link 61, and is also rotatably connected to link 62 at a position separated from joint J2 by ​​a length equivalent to the link length of link 61. This constitutes a first parallel link mechanism in which arm 3a is the fixed link, link 61 is the driving link, link 62 is the driven link, and link 63 is the intermediate link. Furthermore, link 64 is rotatably connected to arm 3c at a position separated from joint J3 by a predetermined length, and is also rotatably connected to link 62 at a position separated from joint J2 by ​​the same predetermined length. This creates a second parallel link mechanism in which arm 3b is a fixed link, link 62 is a driving link, arm 3c is a driven link, and link 64 is an intermediate link. Through the action of these first and second parallel link mechanisms, arm 3c is always maintained parallel to the running surface of the transport trolley or the mounting surface of the robot device 1C, regardless of the rotation angle of arms 3a and 3b.

[0084] The hand portion 4 of the robot arm 2C is attached to the end-effector arm 3c and is controlled by the control device 100C of the robot device 1C to grasp the target object (hereinafter referred to as "grasping target"). The fluid supply device 10C includes, for example, a tank with a closed upper and lower end that can store hydraulic oil as a working fluid, a pump for pumping the hydraulic oil, and a plurality of linear solenoid valves, and is controlled by the control device 100C to supply and discharge hydraulic oil to each double-acting cylinder 7. This allows the robot arm 2C to be driven by hydraulic pressure (fluid pressure) to move the hand portion 4 to the desired position. However, the fluid supply device 10C may supply and discharge a liquid other than hydraulic oil, such as water, to each double-acting cylinder 7, or it may supply and discharge a gas, such as compressed air, to each double-acting cylinder 7.

[0085] Figure 11 is a diagram showing the fluid supply device 10C of the robot device 1C. As shown in the figure, the fluid supply device 10C includes a pump 13, a first relief valve RV1, a second relief valve RV2, a check valve CV, an accumulator 14, a plurality of linear solenoid valves 151-154 as fluid adjustment valves (fluid adjustment section), an on / off solenoid valve 16 as a signal pressure output valve, and a plurality of on / off valves (outflow restriction valves) 171-174. In the fluid supply device 10C, the linear solenoid valve (first solenoid valve) 151 adjusts the hydraulic pressure (drive pressure) to the first fluid chamber 71 of the double-acting cylinder 7 corresponding to joint J1. The linear solenoid valve (second solenoid valve) 152 adjusts the hydraulic pressure to the second fluid chamber 72 of the double-acting cylinder 7 corresponding to joint J1. The linear solenoid valve (first solenoid valve) 153 adjusts the hydraulic pressure to the first fluid chamber 71 of the double-acting cylinder 7 corresponding to joint J2. The linear solenoid valve (second solenoid valve) 154 adjusts the hydraulic pressure to the second fluid chamber 72 of the double-acting cylinder 7 corresponding to joint J2.

[0086] Furthermore, the input port 17i of the on / off valve 171 communicates with the output port 15o of the linear solenoid valve 151, and the output port 17o of the on / off valve 171 communicates with the hydraulic fluid inlet and outlet of the first fluid chamber 71 of the double-acting cylinder 7 corresponding to joint J1. The input port 17i of the on / off valve 172 communicates with the output port 15o of the linear solenoid valve 152, and the output port 17o of the on / off valve 172 communicates with the hydraulic fluid inlet and outlet of the second fluid chamber 72 of the double-acting cylinder 7 corresponding to joint J1. The input port 17i of the on / off valve 173 communicates with the output port 15o of the linear solenoid valve 153, and the output port 17o of the on / off valve 173 communicates with the hydraulic fluid inlet and outlet of the first fluid chamber 71 of the double-acting cylinder 7 corresponding to joint J2. The input port 17i of the on / off valve 174 communicates with the output port 15o of the linear solenoid valve 154, and the output port 17o of the on / off valve 174 communicates with the hydraulic fluid inlet and outlet of the second fluid chamber 72 of the double-acting cylinder 7 corresponding to the joint J2.

[0087] In the robot device 1C described above, if the power supply to the electromagnetic part 16e of the on / off solenoid valve 16 is interrupted due to a power failure, or if the power supply to the electromagnetic part 16e is released in response to an abnormality in the pump 13 or linear solenoid valves 151-154, each on / off valve 171-174 will enter an outflow restriction state. As a result, the spool 17s blocks the hydraulic fluid that has flowed back from the first and second fluid chambers 71, 72 of each double-acting cylinder 7 to the output port 17o of the on / off valve 171-174, thereby restricting the outflow of the hydraulic fluid to the linear solenoid valve 151-154. This effectively suppresses unexpected movements of the robot arm 2C even if an abnormality occurs in the supply of hydraulic fluid to each double-acting cylinder 7, thereby further improving the stability and reliability of the operation of the robot device 1C.

[0088] Furthermore, while the on / off valves 171-174 restrict the outflow of hydraulic fluid from the corresponding first or second fluid chambers 71, 72, if the relative rotation of the two arms 3a, 3b, etc. causes the hydraulic fluid pressure at the output port 17o to exceed the threshold, the hydraulic fluid can be allowed to flow from the first and second fluid chambers 71, 72 to the input port 17i via the output port 17o. As a result, even in the robot device 1C, while the outflow of hydraulic fluid from each double-acting cylinder 7 is restricted by the on / off valves 171-174, if the piston rod 35 of any of the double-acting cylinders 7 is forcibly pulled or pushed in due to the inertia of the robot arm 2C, etc., the rise in hydraulic pressure in the first or second fluid chambers 71, 72 can be suppressed. As a result, the decrease in the durability of each double-acting cylinder 7 due to a malfunction of the fluid supply device 10C can be effectively suppressed, and the increase in the size and weight of the double-acting cylinders 7 and the robot device 1C to suppress the decrease in durability caused by a malfunction of the fluid supply device 10C can be suppressed. Furthermore, instead of the on / off solenoid valve 16 and the multiple on / off valves 171-174, the fluid supply device 10C may be provided with multiple on / off valves 170 and relief valves 19 (see Figure 8) for each of the first and second fluid chambers 71, 72 of each double-acting cylinder 7.

[0089] In addition, in the fluid supply devices 10, 10B, and 10C, at least one of the linear solenoid valves 151-156 may be a normally open valve. In this case, the normally open valve may balance the thrust from the electromagnetic part and the thrust from the hydraulic pressure supplied to the feedback port so as to act in the same direction as the thrust from the electromagnetic part with the biasing force of the spring. Furthermore, at least one of the linear solenoid valves 151-156 may not have a dedicated feedback port and may be configured to apply the output pressure (drive pressure) as feedback pressure to the spool inside the sleeve housing the spool (see, for example, Japanese Patent Application Publication No. 2020-41687). Moreover, at least one of the linear solenoid valves 151-156 may be replaced with a linear solenoid valve that outputs a signal pressure corresponding to the current supplied to the electromagnetic part and a control valve that adjusts the pressure of the hydraulic fluid according to the signal pressure.

[0090] Furthermore, in the fluid supply devices 10, 10B, and 10C, the on / off solenoid valve 16 may be omitted, and instead of the on / off valves 170, 171-176, an electromagnetic on / off valve including an electromagnetic part may be used. Moreover, the fluid supply devices 10, 10B, and 10C may include a flow control valve as a fluid adjustment valve (fluid adjustment unit) that controls the flow rate of liquid (fluid) to the fluid actuators M1-M6 or double-acting cylinders 7 so that the liquid pressure (fluid pressure) detected by a pressure sensor becomes the required pressure. Also, the fluid supply devices 10 and 10B may supply liquids other than hydraulic oil, such as water, or gases such as air to the fluid actuators M1-M6 or double-acting cylinders 7.

[0091] Furthermore, the robotic device 1,1C may include only one joint, or only one or two fluid actuators M1 or double-acting cylinders 7. Also, the robotic device 1,1C is not limited to including a robotic arm 2,2C having at least one fluid actuator M1 or double-acting cylinder 7 and a hand portion 4, but may include at least one fluid actuator and a robotic arm with elements other than the hand portion 4 attached to its end effector, such as a tool like a drill bit or a pressing member for pressing a switch. Furthermore, the robotic device 1,1C may be a walking robot, a wearable robot, or the like.

[0092] Furthermore, the robot arms 2 and 2C of the robot devices 1 and 1C may include a rocking motor (for example, a rocking motor that rotates the base (wrist) of the hand portion 4) as a fluid actuator (double-acting actuator) that drives the arm 3, etc. That is, the robot body of the robot devices 1 and 1C may include at least one of the following: a fluid actuator M1, etc., or a double-acting cylinder 7 and a rocking motor. Moreover, in the robot device 1C, at least one of the double-acting cylinders 7 may be replaced with a double-acting actuator that includes, for example, two single-acting cylinders arranged to counteract each other. Also, the robot arms 2 and 2C of the robot devices 1 and 1C may include an air cylinder as a fluid actuator. Furthermore, it is not necessary for all of the two arms 3, etc. connected via joints J1-J3 to be provided with a pair of fluid actuators (artificial muscles) M; one or more fluid actuators and an elastic body such as a spring or rubber material arranged to counteract the fluid actuator may be connected to any pair of two arms 3, etc. Furthermore, in robotic devices 1,1C, the tank 11 may be supported by the robotic body, such as the robotic arms 2,2C.

[0093] Furthermore, the invention disclosed herein is not limited in any way to the embodiments described above, and it goes without saying that various modifications can be made within the scope of this disclosure. Moreover, the embodiments described above are merely one specific form of the invention described in the summary of the invention, and do not limit the elements of the invention described in the summary of the invention. [Industrial applicability]

[0094] The inventions disclosed herein are applicable in industries such as the manufacturing of robotic devices that include at least one artificial muscle that operates in response to a fluid supply. [Explanation of Symbols]

[0095] 1,1C Robot device, 2 Robot arm, 3,3a,3b,3c Arm, 5 Support member, 7 Double-acting cylinder, 70 Cylinder, 71 First fluid chamber, 72 Second fluid chamber, 74 Piston, 75 Piston rod, 8 Locking mechanism, 10,10B,10C Fluid supply device, 13 Pump, 14 Accumulator, 151,152,153,154,155,156 Linear solenoid valve, 16 On / off solenoid valve, 171,172,173,174,175,176 On / off valve, 18 Switching valve, CV Check valve, J1,J2,J3 Joint, M1,M2,M3,M4,M5,M6 Fluid actuator (artificial muscle).

Claims

1. A robotic apparatus comprising at least one fluid actuator that operates in response to a fluid supply, and a fluid supply device that supplies and discharges the fluid to the fluid actuator, The aforementioned fluid supply device, The fluid supply source and A fluid adjustment unit that adjusts the pressure or flow rate of the fluid from the supply source and supplies it to the fluid chamber of the fluid actuator, An outflow restriction valve that restricts the outflow of the fluid from the fluid chamber of the fluid actuator in response to an abnormality in the fluid supply device, While the outflow restriction valve restricts the outflow of the fluid from the fluid chamber of the fluid actuator, a relief section allows the fluid to flow out of the fluid chamber of the fluid actuator in response to an increase in the fluid pressure in the fluid actuator. Equipped with, The outflow control valve includes an input port to which the fluid from the fluid adjustment unit is supplied, an output port communicating with the fluid actuator, a spool, and a spring that biases the spool. The spool connects the input port and the output port against the biasing force of the spring in response to the supply of signal pressure or the operation of the electromagnetic part, and the biasing force of the spring interrupts the connection between the input port and the output port in response to the cessation of the supply of signal pressure or the cessation of the operation of the electromagnetic part due to an abnormality in the fluid supply device.

2. In the robot device according to claim 1, The fluid actuator is a robotic device that is an artificial muscle including a tube that defines a fluid chamber inside and expands radially and contracts axially in response to an increase in pressure in the fluid chamber.

3. In the robot device according to claim 1, The fluid actuator is a robotic device which is a double-acting actuator including two fluid chambers.

4. A robotic apparatus according to any one of claims 1 to 3, wherein the outflow restriction valve includes the relief portion.

5. In the robot device according to claim 4, The spool has a receiving surface for receiving the fluid flowing from the fluid chamber of the fluid actuator to the output port, and when the supply of the signal pressure is stopped or the operation of the electromagnetic part is stopped, the robotic device connects the input port and the output port against the biasing force of the spring in accordance with the fluid pressure acting on the receiving surface.

6. In the robot apparatus according to any one of claims 1 to 3, The relief section is a relief valve positioned between the outflow restriction valve and the fluid actuator in the robotic device.

7. In the robot apparatus according to any one of claims 1 to 6, A robotic device further comprising two links connected via joints and rotated relative to each other by at least one fluid actuator.

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