JPH06300014A - Actuator controller - Google Patents

Abstract

PURPOSE:To provide an actuator controller capable of ensuring high safety in consideration of a responding time of an operator by enabling the return or the like of a piston after keeping a control condition before failures only for a predetermined time after the occurrence of failures. CONSTITUTION:A change-over valve 33 capable of changing over fluid chambers 23, 24 between a first change-over position (c) in which both chambers communicate to each other and a second change-over position (b) in which both chambers are shut off from each other according to pressure supplied from a pilot path 35 is provided, while a time lag element 50 is provided which has a pressure accumulating means 51 for accumulating by normal working fluid pressure to hold pilot pressure a predetermined pressure when pressure on the supply source side is reduced and a throttle path for connecting the pressure accumulating means 51 or a pilot path 35 through a throttle valve 52a to the supply source side to reduce gradually the pilot pressure from the predetermined pressure in the reduction of the supplied pressure. The time lag element 50 is changed over to the first change-over position (c) after holding the change-over valve 33 by a predetermined time in the second change-over position (b) at the time of the reduction of the supplied pressure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an actuator control device, and more particularly to an actuator control device for controlling an actuator to a predetermined state when a failure occurs.

[0002]

2. Description of the Related Art Generally, in an aircraft or the like, one control target (for example, one control surface) is controlled by a plurality of control systems,
When one of these control systems fails, the other control system controls the controlled object to ensure safety. In such a case, if the hydraulic (hydraulic) actuator of the failed control system maintains the state at the time of the failure occurrence, it adversely affects the control by other control systems. It is necessary to return it to a predetermined position or make it slidable by an external force. Therefore, conventionally, in the device for controlling the operation of the actuator,
There is one that has a function to control the actuator to a predetermined state as described above when a failure occurs.

As an actuator control device of this type,
For example, JP-A-63-297802 and JP-A-2-1.
The one described in Japanese Patent No. 13101 is known. In these actuator control devices, when the servo control valve that controls the supply and discharge of the working fluid to and from the actuator falls into an inoperable state due to an electric system failure, a predetermined solenoid valve is operated to hydraulically operate the servo control valve. The valve element is moved to a predetermined position to return the actuator to the neutral position.

[0004]

However, such a conventional actuator control device can deal with the failure of the electric system, but cannot deal with the failure of the hydraulic system. In addition, the operator's response when a failure occurs (specifically, for example, when pilot operation was operated by hydraulically amplifying the pilot's operation during normal operation, the minimum control system due to hydraulic failure is input operation with limited output Switch to the control mode, and maintain the position of other control systems at the time of failure until human body control stabilizes after the failure, and then return to the predetermined position (usually the neutral position) at a speed that does not affect human-powered operation. Since the actuator is returned to the neutral position irrespective of the time required), the return timing of the piston has not been a suitable timing in consideration of the operator's response. That is, these points have been problems to be improved in order to secure higher safety.

Therefore, according to the present invention, when the control state before the failure is maintained for a predetermined time when the failure occurs, the piston can be returned to a predetermined position or moved by an external force.
It is an object of the present invention to provide an actuator control device capable of ensuring a high degree of safety in consideration of handling by an operator.

[0006]

In order to achieve the above object, the invention according to claim 1 is the fluid chamber of an actuator, wherein a piston is housed in a cylinder and a plurality of fluid chambers are defined on both sides of the piston. A supply / discharge control valve for supplying a working fluid from a supply source or discharging the working fluid from the fluid chamber to the outside, and switching the connection of the flow path between the supply / discharge control valve and the actuator. In the actuator control device including a switching valve, the switching valve,
According to a pilot pressure supplied from a predetermined pilot passage, it is possible to switch between a first switching position in which the fluid chambers on both sides of the piston communicate with each other and a second switching position in which the fluid chambers are blocked from each other. Together with the pressure accumulating means for accumulating the pilot pressure at a predetermined pressure when the pressure on the supply source side is reduced by the normal working fluid pressure from the supply source side, the pressure accumulating means or the pilot passage through the throttle valve. A time delay element having a throttle passage connected to the supply source side to gradually reduce the pilot pressure from the predetermined pressure when the pressure on the supply source side decreases. When it is lowered, the switching valve is held in the second switching position for a predetermined time by the time delay element, and is switched to the first switching position after the predetermined time.

According to a second aspect of the present invention, there is provided a cam member which engages with the piston of the actuator and which drives the piston when moving within a predetermined movement range, and receives the pilot pressure. A pressure receiving member for moving the cam member out of the predetermined movement range, and a predetermined movement of the cam member when the working fluid pressure in the pilot passage decreases by constantly urging the cam member or the pressure receiving member toward a predetermined position. An elastic member for returning to a specific position within the range is provided, and the pressure accumulating member is configured by the pressure receiving member and the elastic member. The invention according to claim 3 is characterized in that the time delay element is A slide valve provided in the throttle passage on the pilot passage side of the throttle valve, and when the pressure on the supply source side is reduced, the slide valve is provided a predetermined time after the pressure is reduced. It is characterized in that the de-valve communicates directly said pilot passage to the supply source side.

[0008]

According to the first aspect of the invention, when the normal working fluid pressure is supplied from the supply source, the actuator is controlled by the supply / discharge control valve and the pressure accumulating means of the time delay element is operated by the normal working fluid pressure. Accumulate by. On the other hand, when the working fluid pressure on the supply source side decreases due to a decrease in the working fluid pressure from the supply source or a failure of the supply / discharge control valve, etc., the pressure accumulating means operates to keep the pilot pressure at a predetermined pressure, and the throttle passage is opened. The pressure accumulating means or the pilot passage is connected to the supply source side via a throttle valve to gradually reduce the pilot pressure from the predetermined pressure. Therefore, when the working fluid pressure on the supply source side decreases, the working fluid pressure in the pilot passage is maintained at a predetermined pressure level for a predetermined time, the switching valve is held at the second switching position, and after the predetermined time, the working fluid pressure is reduced. When the pressure drops below the set value, the switching valve switches to the first switching position.
When the switching valve is in the first switching position, the fluid chambers on both sides of the piston communicate with each other, and when the switching valve is in the second switching position, the communication between the fluid chambers is blocked. As a result, after the control state before the failure is maintained for a predetermined time required for the operator's response when the failure occurs, the piston can return to the predetermined position or can follow the external force and move.

According to the second aspect of the present invention, when the pressure receiving member receives the pilot pressure, the cam member is driven out of the predetermined movement range, so that the piston is not driven by the cam member, but the working fluid from the supply source is used. When the working fluid pressure in the pilot passage decreases due to a decrease in pressure or a failure of the supply / discharge control valve, the elastic member returns the cam member to a specific position within its predetermined movement range after a predetermined time has elapsed, and the actuator accordingly. The piston returns to the predetermined position. Further, since the pressure receiving member and the elastic member constitute pressure accumulating means, the pressure accumulating means of the time delay element and the piston returning means at the time of occurrence of a failure can be combined.

Further, according to the third aspect of the present invention, the slide valve provided in the time delay element causes the pilot passage to directly communicate with the supply source side after a predetermined time has elapsed from the pressure drop on the supply source side. The piston of the actuator can be quickly returned to the predetermined position.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be specifically described below with reference to the drawings. 1 and 2 are views showing an embodiment of an actuator control device according to the invention described in claims 1 to 3. First, the configuration will be described.

In FIG. 1, reference numeral 1 is an actuator unit. The actuator unit 1 is composed of an actuator 2, an actuator control device 3, and a unit body case 4 accommodating them. The actuator 2 has a cylinder 21 and a piston 22 slidably inserted in the cylinder 21.
A plurality of fluid chambers 23, 24 are defined on both sides of the inner piston 22. That is, the actuator 2 is operated by the differential pressure between the fluid chambers 23 and 24 partitioned by the piston 22.
For controlling a control object (for example, a control surface) (not shown) connected to the piston 22 via the connection pin 25. A piston 22 of another actuator 2 (not shown) is also connected to the connecting pin 25 in parallel, and the control target is controlled by a plurality of actuator units 1. Therefore, when any one of the plurality of actuator units 1 fails, another actuator unit 1 can control the control target. The displacement of the piston 22 is detected by a known position sensor 29 such as a differential transformer.

Further, the actuator control device 3 includes a supply port 41 and a return port 42 formed in the unit body case 4.
Solenoid valve 31 (supply / exhaust control valve) connected to each, a control valve 32 (supply / exhaust control valve) connected to the outlet port of the solenoid valve 31 and the return port 42, and the fluid chambers 23, 24
And a switching valve 33 provided between the control valve 32 and the outlet port of the control valve 32 to switch the connection of the flow paths 43 and 44 therebetween. The solenoid valve 31 has a spring 31 when it is not energized.
When the supply port 41 is shut off at the discharge position j by the urging force of f, the inlet port of the control valve 32 is communicated with the return port 42, but when excited, the spring 31f is compressed and switched to the supply position i. The inlet port of the control valve 32 is communicated with the supply port 41. The control valve 32 is a so-called force motor 32m (DC motor) corresponding to a deviation between a command input from a control unit (not shown) and the position detection signal of the position sensor 29.
Is controlled by the hydraulic chamber 23, 24 of the actuator 2 to supply a working fluid (working oil) from a supply source (not shown),
The working fluid from the fluid chambers 23 and 24 can be discharged to an external reservoir tank, and all ports can be shut off. The switching valve 33 has a predetermined pilot passage 3
By compressing or expanding the spring 36 according to the pilot pressure from the pistons 4 and 35, the fluid chambers on both sides of the piston 22
Switch to either a switching position a for connecting 23, 24 to the outlet port of the control valve 32 or a switching position b (second switching position) for shutting off the fluid chambers 23, 24 and the outlet port of the control valve 32. , Or the fluid chambers 23, 24 with fixed throttle valves
It is possible to switch to a switching position c (first switching position) in which they communicate with each other via 33g. That is, the switching valve 33
Is switched to the switching position a when the pilot pressure is at the normal pressure level, and switched to the switching position b when the pilot pressure is at a predetermined value level slightly lower than the normal pressure level, and the pilot pressure is changed due to some failure. When it falls below a predetermined value level, it switches to the switching position c.

Further, in the actuator control device 3, a time delay element is provided between the fluid pressure passage 46 connected to the outlet port of the solenoid valve 31 and the pilot passage 35, that is, between the supply source side and the pilot passage 35. 50 are provided. The time delay element 50 has a pressure accumulating means 51 and a throttle passage 52, and the pressure accumulating means 51 has a passage 46 on the supply source side.
In order to maintain the pilot pressure in the pilot passage 35 at a predetermined pressure when the pressure of the pressure is reduced, the pressure is accumulated by the normal working fluid pressure from the fluid pressure passage 46. In particular,
The pressure accumulating means 51 of this embodiment includes a pilot passage 35 and a throttle passage.
A pressure accumulating chamber 53 provided between 52, a ram 54 (pressure receiving member) that receives the working fluid pressure in the pressure accumulating chamber 53, and a ram 54 that is constantly urged toward a predetermined position (upward in FIG. 1). Elastic member 55
And the pressure accumulation chamber 53 provided between the pressure accumulation chamber 53 and the fluid pressure passage 46.
Is configured to include a check valve 56 that closes when the pressure becomes higher than the fluid pressure passage 46, and when the normal working fluid pressure is acting in the pressure accumulating chamber 53, the elastic member 55 is actuated by the working fluid pressure. Accumulates by elastically deforming. Then, when the pressure in the pressure accumulating chamber 53 decreases, the pressure accumulating means 51 causes the elastic member 55 to move the ram 54
By pushing up, the working fluid in the pressure accumulating chamber 53 can be pressurized to a predetermined value in cooperation with the fixed throttle valve 52a in the throttle passage 52 (described later). In this embodiment, since the switching valve 33 is configured to compress the spring 36 according to the pilot pressure, the switching valve 33 itself can also have a function as pressure accumulating means.

The ram 54 and the elastic member 55 together with the annular cam member 57 constitute a piston return mechanism 60.
The piston return mechanism 60 returns the piston 22 to the neutral position (predetermined position) when a failure occurs, and the cam member 57 has a cam surface 57a that engages with the roller 22r mounted on the piston 22, The piston 22 is driven by the cam surface 57a when the piston 22 is rotated within a predetermined rotation (movement) range. Further, when the normal working fluid pressure is supplied into the pressure accumulating chamber 53, the cam member 57 has its lower end moved by the ram 54 receiving the pressure (pilot pressure) in the pressure accumulating chamber 53 and moving downward in FIG. Is pushed down by the roller 54a of the
It moves out of the predetermined rotation range (state of FIG. 1). When the cam member 57 is out of the predetermined rotation range, the piston 22 is in a slidable state. on the other hand,
When the pressure in the pressure accumulating chamber 53 falls below a predetermined value level due to some failure, the cam member 57 is pushed up by the elastic member 55 and returns to the specific position within the predetermined moving range. Here, the specific position within the predetermined movement range means the cam member 57.
Is a rotational position in which the roller 22r enters into the concave portion 57b forming a part of the cam surface 57a within the predetermined rotational range, and the piston 22 is in a predetermined neutral position when the cam member 57 is rotated to this rotational position. Return to position.

The throttle passage 52 is a pressure accumulating means 51 (pilot passage
35) may be connected to the fluid pressure passage 46 via a fixed throttle valve 52a and a check valve 52b in parallel with the fixed throttle valve 52a. When the fluid pressure passage 46 is at a normal working fluid pressure, the working fluid pressure is changed to a check valve. The pressure is supplied to the pressure accumulating means 51 via 52b, and when the pressure on the fluid pressure passage 46 side falls below a predetermined level, the check valve 52b is closed and the fixed throttle valve 52a is used to change the pressure on the pilot passage 35 side from the predetermined pressure. It is designed to gradually decrease.

Further, from the fixed throttle valve 52a to the pilot passage
A slide valve 71 and a spring 72 are provided in the throttle passage 52 on the 35 side, and a damper chamber 73 that houses these is defined. When the pressure in the fluid pressure passage 46 decreases, the slide valve 71 travels a predetermined stroke distance h within a predetermined time after the pressure reduction, and after the predetermined time elapses, the pilot passage 35 passes through the communication passage 75 and the fluid pressure passage 46. To communicate directly with. This predetermined elapsed time can be arbitrarily set by selecting the size of the throttle of the fixed throttle valve 52a and the stroke distance h of the slide valve 71.

Regarding the structure around the throttle passage 52,
For example, as shown in FIG. 2, by mounting a slidable valve element 74 at one end of the slide valve 71, the number of parts can be reduced. Next, the operation will be described. First, when a normal working fluid pressure is supplied from the supply source to the supply port 41, the inlet port of the control valve 32 and the fluid pressure passage 46 are supplied via the solenoid valve 31.
Is supplied with normal working fluid pressure. At this time, the control valve 32
The supply / discharge of the working fluid to / from the fluid chambers 23, 24 is controlled by the control of the actuator 2 by the control. Further, when the working fluid pressure in the fluid pressure passage 46 is introduced into the pressure accumulating chamber 53 via the check valve 56, the ram 54 elastically deforms the elastic member 55 via the cam member 57, and the pilot passage 35. And fluid pressure passage on the supply side
The pressure accumulating means 51 provided between 46 and 46 accumulates pressure. Further, when the ram 54 receives the pilot pressure, the cam member 57 is driven outside the predetermined movement range, so that the piston 22 can slide without being driven by the cam member 57.

In such a state, the working fluid pressure from the supply source is lowered for some reason, or the solenoid valve 31 for controlling the supply and discharge of the working fluid is broken, for example. When the fluid pressure decreases, the pressure accumulating means 51 operates so as to keep the pilot pressure in the pilot passage 35 at a predetermined pressure, and the throttle passage 52 causes the pressure accumulating means 51 (or pilot passage 35) to be supplied via the fixed throttle valve 52a. Is connected to the fluid pressure passage 46 on the side, and the pilot pressure in the pilot passage 35 is gradually reduced from the predetermined pressure. Therefore, when the working fluid pressure in the fluid pressure passage 46 decreases, the working fluid pressure in the pilot passage 35 is kept at the predetermined pressure level for a predetermined time, that is, the time when the slide valve 71 strokes the distance h. 33 is held in the second switching position b. In addition, after the lapse of the predetermined time, the slide valve 71
When the pilot passage 35 communicates with the fluid pressure passage 46 through the communication passage 75 by the operation of, the pilot passage 35 and the pressure accumulation chamber
The working fluid pressure in 53 immediately drops below the set value and the switching valve
33 is switched to the first switching position c. And the switching valve 33
Is switched to the first switching position c, the fluid chambers 23 and 24 on both sides of the piston 22 communicate with each other. Further, after a predetermined time has elapsed from the decrease of the working fluid pressure in the pilot passage 35,
Since the elastic member 55 returns the cam member 57 to the specific position within the predetermined movement range, the piston 22 of the actuator 2 is returned to the predetermined position accordingly. Therefore, when a failure occurs, the operator (e.g., pilot) can return the piston 22 to the neutral position after maintaining the control state before the failure for a predetermined time necessary for determining the response to the failure. It is possible to secure a high degree of safety in consideration of the operator's response.

Further, in this embodiment, since the ram 54 and the elastic member 55 constitute the pressure accumulating means 51, the pressure accumulating means 51 of the time delay element 50 and the returning means of the piston 22 when a failure occurs can be used in common. The configuration can be simplified. Furthermore, the slide valve 71 provided in the time delay element 50 allows the pilot passage 35 to directly communicate with the fluid pressure passage 46 on the supply source side after a predetermined time from the pressure drop on the supply source side, while waiting for the operator's response decision. After determining the correspondence, the piston 22 can be quickly returned to the predetermined position, and safety can be improved.

FIG. 3 is a diagram showing another embodiment of the actuator control device according to the present invention.
In this embodiment, the single rod type actuator 10
2, the control valve 132 and the switching valve 133 corresponding thereto are provided, and the piston return mechanism 80 is provided in the actuator 102 instead of the piston return mechanism 60 of the above-mentioned example. Accumulation means 1 by 53
Make up 51. Since the other configurations are almost the same as those in the above-described example, the same or corresponding members as those in the above-mentioned example are denoted by the same reference numerals, and the duplicated description of the contents is omitted.

In FIG. 3, the left and right pressure receiving areas of the piston 122 of the actuator 102 are different. Normally, the solenoid valve 31 and the switching valve 133 are provided in the fluid chamber 124 on the side of the left and right pressure receiving surfaces which has a small pressure receiving area. The working fluid pressure from the supply source is constantly introduced. Further, the switching valve 133 is provided in the fluid chamber 123.
The outlet port of the control valve 132 is connected through the control valve 132, and the operation of the actuator 102 is controlled by supplying and discharging the working fluid into and from the fluid chamber 123 by the control valve 132.

The piston return mechanism 80 is a position sensor.
There are retainers 81 and 82 which are externally mounted on the tubular fixed side member 29a of 29 so as to be movable only within a predetermined range, and a compression spring 83 which is contracted to the fixed side member 29a via the retainers 81 and 82. The retainers 81 and 82 have inner diameters on the fixed side of the position sensor 29.
Piston 1 of actuator 102 with an outer diameter smaller than 29a
It is larger than the inner diameter of 22 (the piston 122 and the fixed-side member 29a have recessed shapes corresponding to the retainers 81 and 82, respectively). The compression spring 83 is compressed via the retainers 81 and 82 when the piston 122 is displaced from the neutral position, and the switching valve 133 is switched to the switching position c (first switching position) and the fluid chambers 123 and 124. Fixed throttle valve 133g
When they are communicated with each other, the piston 122 is returned to a predetermined neutral position or expanded or contracted by an external force acting on the piston 122. Note that 29b is a moving side member of the position sensor 29.

The time delay element 50 has a pressure accumulating means 151 and a throttle passage 52, and a slide valve 71 and a spring 72 are housed in the throttle passage 52 as in the above example. The pressure accumulating means 151 is provided between the pilot passage 35 and the throttle passage 52, a pressure accumulating chamber 53, a switching valve 33 for receiving the working fluid pressure in the pressure accumulating chamber 53, and the switching valve 33 for pressurizing the working fluid pressure. And a check valve 56 that is provided between the pressure accumulation chamber 53 and the fluid pressure passage 46 and closes when the pressure accumulation chamber 53 becomes higher than the fluid pressure passage 46. When the normal working fluid pressure is acting in the pressure accumulating chamber 53, the spring 136 elastically deforms by the working fluid pressure to accumulate the pressure. When the pressure on the supply source side decreases, the pressure accumulating means 151 moves the switching valve 133 in the pressurizing direction by the spring 136, and the fixed throttle valve 52a in the throttle passage 52.
Working fluid in the accumulator 53 at a predetermined pressure (switching position b
Can be applied to the set pressure).

Also in the present embodiment, when the actuator 102 is kept in the control state before the failure for a predetermined time when a failure occurs, the piston 122 can be returned to a predetermined position and moved by an external force so that the operator It is possible to secure a high degree of safety in consideration of measures, and it is possible to obtain the same operational effects as the above example.

[0026]

According to the first aspect of the present invention, the pressure is accumulated by the pressure accumulating means by the normal working fluid pressure from the supply source, and when the working fluid pressure on the supply source side is lowered due to a failure or the like, the pressure accumulating means. Since the pilot pressure to the switching valve is gradually reduced from the predetermined pressure via the throttle passage that connects the supply source side with the supply source side, when the working fluid pressure on the supply source side decreases, the pilot pressure is maintained for a predetermined time. It is possible to keep the switching valve at the second switching position while maintaining the predetermined pressure level, and switch the switching valve to the first switching position after the predetermined time. As a result, after maintaining the control state before failure for a predetermined time required for operator response when a failure occurs, it is possible to return the piston to a predetermined position or move in response to external force. It is possible to provide an actuator control device capable of ensuring a high degree of safety in consideration of the above.

Further, according to the second aspect of the present invention, the cam member is driven outside the predetermined movement range while the elastic member is elastically deformed by the pressure receiving member that receives the normal pilot pressure, and the normal stroke of the piston is enabled. On the other hand, if the working fluid pressure in the pilot passage decreases due to a failure, etc., the cam member is returned to the specified position within the specified movement range by the elastic member after a specified time from the pressure decrease, and the actuator piston is returned to the specified position. I'm trying to
The pressure receiving member and the elastic member constitute the pressure accumulating means, and these can also be used as the piston returning means, so that the structure can be simplified.

Further, according to the third aspect of the invention, since the slide valve provided in the time delay element allows the pilot passage to directly communicate with the supply source side after a predetermined time has elapsed from the pressure drop on the supply source side. After the elapse of the predetermined time, the piston of the actuator can be quickly returned to the predetermined position, and appropriate and quick response to a failure or the like can be performed.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an embodiment of an actuator control device according to the present invention.

FIG. 2 is a sectional view of a specific example of a throttle passage of the time delay element.

FIG. 3 is an overall configuration diagram of another embodiment of the actuator control device according to the present invention.

[Explanation of symbols]

 1 Actuator unit 2,102 Actuator 3 Actuator control device 4 Unit body case 21,121 Cylinder 22,122 Piston 23,24,123,124 Fluid chamber 31 Solenoid valve (supply / discharge control valve) 32,132 Control valve (supply / discharge control) Valve) 33, 133 Switching valve 36, 136 Spring 43, 44 Flow path (flow path between the two) 46 Fluid pressure passage (passage on the supply source side) 50 Time delay element 51, 151 Pressure accumulating means 52 Throttle passage 52a Fixed throttle valve 54 Ram (pressure receiving member) 55 Elastic member 56 Check valve 57 Cam member 57a Cam surface 60 Piston return mechanism 71 Slide valve 80 Piston return mechanism b Switching position (second switching position) c Switching position (first switching position)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akira Ito 1110-1 Miyazaki, Taryo-cho, Fuwa-gun, Gifu Prefecture Ozaki, Teijin Seiki Co., Ltd. Gifu No. 1 Factory

Claims (3)

[Claims] Claim: What is claimed is: 1. A working fluid from a supply source is supplied to the fluid chamber of an actuator, wherein a piston is housed in a cylinder and a plurality of fluid chambers are defined on both sides of the piston. In the actuator control device, the supply / discharge control valve for discharging the gas to the outside and the switching valve provided between the supply / discharge control valve and the actuator for switching the connection of the flow path between the two are provided. According to the pilot pressure supplied from the pilot passage, it is possible to switch between a first switching position where the fluid chambers on both sides of the piston communicate with each other and a second switching position where the communication between the fluid chambers is cut off. A pressure accumulating means for accumulating the pilot pressure at a predetermined pressure when the pressure on the supply source side is reduced by a normal working fluid pressure from the supply source side; A throttle passage that connects the pilot passage to the supply source side via a throttle valve and gradually reduces the pilot pressure from the predetermined pressure when the pressure on the supply source side decreases; Actuator control characterized in that, when the working fluid pressure on the supply source side decreases, the switching valve is held in the second switching position for a predetermined time by the time delay element and switched to the first switching position after the predetermined time. apparatus. 2. A cam member that has a cam surface that engages with a piston of the actuator, and that drives the piston when moving within a predetermined movement range; and a cam member that receives the pilot pressure to move the cam member within the predetermined movement range. A pressure receiving member that moves outward, and a cam member or pressure receiving member that is constantly urged toward a predetermined position to return the cam member to a specific position within the predetermined movement range when the working fluid pressure in the pilot passage decreases. The actuator control device according to claim 1, further comprising an elastic member, wherein the pressure accumulating member is configured by the pressure receiving member and the elastic member. 3. The time delay element has a slide valve provided in the throttle passage on the pilot passage side of the throttle valve, and when the pressure on the supply source side decreases, a predetermined time elapses from the decrease of the pressure. 3. The actuator control device according to claim 1, wherein the slide valve causes the pilot passage to directly communicate with the supply source side later.