Actuator control device

Abstract

An actuator control device is provided. The actuator control device of one embodiment of the present application includes an outlet throttle valve that discharges working fluid from a first fluid pressure chamber of an actuator to a tank using a first pilot pressure or a second pilot pressure, an inlet throttle valve that outputs the working fluid from a working fluid source to a second fluid pressure chamber of the actuator using the first pilot pressure or the second pilot pressure, and a switching mechanism that switches based on at least one of the first pilot pressure and the second pilot pressure to output one of the first pilot pressure and the second pilot pressure to the outlet throttle valve and to output the other of the first pilot pressure and the second pilot pressure to the inlet throttle valve.

Description

Technical Field

[0001] This disclosure relates to an actuator control device for controlling the operation of an actuator. Background Technology

[0002] Fluid-driven actuators are used in various types of machinery, including construction machinery. Fluid-driven actuators include fluid pressure cylinders such as hydraulic cylinders. Fluid pressure cylinders found in construction machinery include boom cylinders for driving the boom, stick cylinders for driving the stick, and bucket cylinders for driving the bucket.

[0003] Conventional actuator control devices for controlling the operation of actuators include a control valve located between the actuator, the working fluid source, and the tank. The control valve has a single valve stem capable of axial movement. Inlet / outlet throttling control is performed to adjust the flow rate of the working fluid supplied to and discharged from the fluid pressure cylinder based on the axial position of the valve stem. Conventional actuator control devices utilizing a control valve with a single valve stem for inlet / outlet throttling control are disclosed, for example, in Japanese Patent Application Publication No. 2003-269411.

[0004] To properly control inlet / outlet throttling using a single valve stem, a circumferentially extending groove (also known as a "throttling section") needs to be provided at an appropriate location on the outer surface of the valve stem. The position and size of the throttling section of the valve stem are adjusted using experimental data obtained by actually operating the actuator of the controlled object using a prototype of the valve stem. Multiple prototypes are usually required.

[0005] As mentioned above, for actuator control devices that use a single valve stem for inlet / outlet throttling control, there is a problem that it is difficult to install an appropriate throttling section on the valve stem. Therefore, an actuator control device using the IMV (Independent Metering Valve) method, which independently controls the positions of multiple valve stems to perform inlet and outlet throttling control, has been proposed. A conventional IMV-based actuator control device has been disclosed in Japanese Patent Application Publication No. 2001-003905.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2003-269411

[0009] Patent Document 2: Japanese Patent Application Publication No. 2001-003905 Summary of the Invention

[0010] The problem the invention aims to solve

[0011] Conventional actuator control devices employing IMV (Inlet Valve Variable Valve) include: two valve spools for inlet throttling control, two valve spools for outlet throttling control, and four solenoid proportional valves for independently controlling the positions of these four valve spools. In other words, conventional IMV-based actuator control devices have four valve spools and four solenoid proportional valves.

[0012] The purpose of this disclosure is to alleviate or resolve at least some of the aforementioned prior art problems. Specifically, one objective of this disclosure is to provide an actuator control device for inlet / outlet throttling control with a simpler structure. Other objectives of this disclosure, besides those described above, will become clear from all the details provided in this specification.

[0013] Solution for solving the problem

[0014] An actuator control device according to one embodiment of the present invention comprises: an outlet throttle valve that discharges working fluid from a first fluid pressure chamber of the actuator to a tank using a first pilot pressure or a second pilot pressure; an inlet throttle valve that outputs the working fluid from a working fluid source to a second fluid pressure chamber of the actuator using the first pilot pressure or the second pilot pressure; and a switching mechanism that switches based on at least one of the first pilot pressure and the second pilot pressure to output one of the first pilot pressure and the second pilot pressure to the outlet throttle valve and the other of the first pilot pressure and the second pilot pressure to the inlet throttle valve.

[0015] In one embodiment of the present invention, the switching mechanism switches by moving the outlet throttle valve.

[0016] In one embodiment of the present invention, the switching mechanism comprises: a first selection valve, which is switchable to a first position for outputting the first pilot pressure to the outlet throttle valve or a second position for outputting the first pilot pressure to the inlet throttle valve; and a second selection valve, which is switchable to a third position for outputting the second pilot pressure to the inlet throttle valve or a fourth position for outputting the second pilot pressure to the outlet throttle valve.

[0017] In one technical solution of the present invention, the switching mechanism switches the first selection valve to the first position and the second selection valve to the third position based on the situation that the first pilot pressure is received when the second pilot pressure is not supplied.

[0018] In one technical solution of the present invention, the switching mechanism switches the first selection valve to the second position and the second selection valve to the fourth position based on the condition that the second pilot pressure is received when the first pilot pressure is not supplied.

[0019] In one embodiment of the present invention, the inlet throttle valve outputs the working fluid to the actuator according to the first pilot pressure or the second pilot pressure.

[0020] In one embodiment of the present invention, the outlet throttle valve discharges the working fluid from the actuator according to the first pilot pressure or the second pilot pressure.

[0021] In one embodiment of the present invention, the inlet throttle valve is disposed between the actuator and the first working fluid source and the second working fluid source.

[0022] In one embodiment of the present invention, the inlet throttle valve is switched between the following positions: a position where the working fluid is output to the actuator from either the first working fluid source or the second working fluid source; and a position where the working fluid is output to the actuator from both the first working fluid source and the second working fluid source.

[0023] The effects of the invention

[0024] According to the technical solution of the present invention, an actuator control device that uses multiple valve stems to perform inlet throttling control and outlet throttling control can be realized with a simpler structure. Attached Figure Description

[0025] Figure 1 This is a schematic diagram illustrating an actuator control device according to one embodiment of the present invention.

[0026] Figure 2a It is used to explain for Figure 1 The diagram illustrates the action of the actuator control device causing the actuator to contract. Figure 2a In the middle, the outlet throttle valve 6 is connected to the first fluid pressure chamber 8a of the actuator 8.

[0027] Figure 2b It is used to explain for Figure 1 The diagram illustrates the action of the actuator control device causing the actuator to contract. Figure 2b In the middle, the outlet throttle valve 6 is connected to the first fluid pressure chamber 8a of the actuator 8, and the inlet throttle valve 5 is connected to the second fluid pressure chamber 8b of the actuator 8.

[0028] Figure 3a It is used to explain for Figure 1The diagram illustrates the action of the actuator control device to extend the actuator. It is a schematic representation. Figure 1 A diagram of the actuator control device. In Figure 3a In the middle, the outlet throttle valve 6 is connected to the second fluid pressure chamber 8b of the actuator 8.

[0029] Figure 3b It is used to explain for Figure 1 The diagram illustrates the action of the actuator control device causing the actuator to extend. Figure 3b In the middle, the outlet throttle valve 6 is connected to the second fluid pressure chamber 8b of the actuator 8, and the inlet throttle valve 5 is connected to the first fluid pressure chamber 8a of the actuator 8.

[0030] Figure 4 This is a schematic diagram illustrating an actuator control device according to another embodiment of the present invention.

[0031] Explanation of reference numerals in the attached figures

[0032] 1. 101. Actuator control device; 2. 102. Working fluid source; 3. Tank; 4. 104. Check valve; 5. 105. Inlet throttle valve; 6. Outlet throttle valve; 8. Actuator; 8a. First fluid pressure chamber; 8b. Second fluid pressure chamber; 10. Controller; 20. Switching mechanism; 21. First selector valve; 22. Second selector valve; 31. First electromagnetic proportional valve; 32. Second electromagnetic proportional valve. Detailed Implementation

[0033] Hereinafter, various embodiments of the present invention will be described with appropriate reference to the accompanying drawings. Furthermore, common components used in the various drawings are labeled with the same reference numerals in those drawings. It should be noted that, for ease of explanation, the drawings are not necessarily shown at an exact scale. In each drawing, for the sake of convenience, some components are sometimes omitted.

[0034] This invention is applicable to actuator control devices that control the operation of fluid pressure actuators divided into at least two fluid pressure chambers. (See reference...) Figure 1 An actuator control device of one aspect of the present invention will be described.

[0035] Figure 1 This is a schematic diagram illustrating an actuator control device 1 according to one embodiment of the present invention. The actuator control device 1 drives a component of a driven object by activating an actuator 8. Components driven by the actuator 8 include, for example, the boom, stick, and bucket of construction machinery, as well as other movable components of construction machinery. The actuator control device 1 is applicable to various types of machinery other than construction machinery.

[0036] In the illustrated embodiment, the actuator control device 1 includes: a working fluid source 2 that supplies working fluid to the actuator 8; a tank 3 for storing the working fluid discharged from the actuator 8; a check valve 4; an inlet throttle valve 5; an outlet throttle valve 6; a controller 10; a switching mechanism 20; a first electromagnetic proportional valve 31; and a second electromagnetic proportional valve 32.

[0037] Working fluid source 2 ejects working fluid. The working fluid ejected from working fluid source 2 is output to actuator 8 via inlet throttle valve 5. Working fluid source 2 is, for example, a variable capacity pump capable of adjusting the amount of working fluid ejected. A check valve 4 is provided between working fluid source 2 and inlet throttle valve 5 to maintain negative pressure.

[0038] Actuator 8 may be, for example, a hydrodynamic actuator driven by a working fluid. Actuator 8 may also be a hydraulic actuator driven by working oil. Actuator 8 may also be a pneumatic actuator operating with compressed air or any hydrodynamic actuator operating with a working fluid other than these. Actuator control device 1 may also include multiple actuators.

[0039] The actuator 8 is configured such that a piston 8c housed within a hollow cylinder divides the cylinder into a first fluid pressure chamber 8a and a second fluid pressure chamber 8b. The cylinder of the actuator 8 is configured such that one side is open and the other closed along its length. A piston rod 8d is connected to the piston 8c. A portion of the piston rod 8d protrudes outward from the cylinder. The tip of the piston rod 8d is connected to a movable component such as the boom, stick, or bucket. The actuator 8 may also include a position sensor for detecting the position of the piston 8c. This position sensor is, for example, a linear variable differential transformer (LVDT).

[0040] The controller 10 includes: a processor for performing various calculations; a memory for storing various programs and data; and a device interface for connecting to various sensors and other devices. The controller 10 outputs control pulses to the electromagnetic proportional valves 31 and 32, thereby adjusting the flow rate of the pilot pressure output from the electromagnetic proportional valves 31 and 32. When the actuator control device 1 is mounted on construction machinery, the controller 10 can receive control signals associated with the operation of the operating levers of the construction machinery, and control the electromagnetic proportional valves 31 and 32 according to these control signals.

[0041] The first electromagnetic proportional valve 31 and the second electromagnetic proportional valve 32 are connected to a pilot pressure source (not shown). The first electromagnetic proportional valve 31 is connected to the switching mechanism 20 via flow path 13a, and the second electromagnetic proportional valve 32 is connected to the switching mechanism 20 via flow path 13d. The first electromagnetic proportional valve 31 has a solenoid coil, a drive rod that moves axially driven by the solenoid coil, and a pilot valve column that moves axially by the thrust received from the drive rod. The first electromagnetic proportional valve 31 and the second electromagnetic proportional valve 32 themselves can also be known electromagnetic proportional valves. The input current input to the solenoid coil is determined according to the control pulse from the controller 10. The first electromagnetic proportional valve 31 is provided with a flow path connecting the pilot pressure source and flow path 13a. The opening area of ​​this flow path varies depending on the axial position of the pilot valve column. The first electromagnetic proportional valve 31 is capable of outputting pilot fluid from the pilot pressure source to flow path 13a at a flow rate corresponding to the opening area that varies according to the axial position of the pilot valve column. The second electromagnetic proportional valve 32 has the same constituent elements as the first electromagnetic proportional valve 31. The second electromagnetic proportional valve 32 is capable of supplying pilot fluid from a pilot pressure source to the flow path 13d at a flow rate corresponding to an opening area that varies according to the axial position of the pilot valve stem. In this specification, the pilot fluid or pilot pressure output from the first electromagnetic proportional valve 31 is sometimes referred to as the first pilot pressure, and the pilot fluid or pilot pressure output from the second electromagnetic proportional valve 32 is sometimes referred to as the second pilot pressure.

[0042] An inlet throttle valve 5 is disposed between the actuator 8 and the working fluid source 2. The first fluid pressure chamber 8a of the actuator 8 is connected to the inlet throttle valve 5 via a first port P1, flow path 11a, and flow path 11b. The second fluid pressure chamber 8b of the actuator 8 is connected to the inlet throttle valve 5 via a port P2, flow path 11d, and flow path 11e. Additionally, the inlet throttle valve 5 is also connected to the switching mechanism 20 to receive pilot pressure. Specifically, the inlet throttle valve 5 is connected to the switching mechanism 20 via flow paths 13b and 13e. The inlet throttle valve 5 has at least one pilot pressure chamber. Depending on the switching mechanism 20, pilot pressure is output from either the first electromagnetic proportional valve 31 or the second electromagnetic proportional valve 32 to the at least one pilot pressure chamber of the inlet throttle valve 5.

[0043] The inlet throttle valve 5 has a valve stem that is housed within the internal space of the manifold. The valve stem of the inlet throttle valve 5 is sometimes referred to as the inlet throttle valve stem. The inlet throttle valve 5 is configured such that the valve stem is axially displaced by pilot pressure from either the solenoid proportional valve 31 or the second solenoid proportional valve 32, thereby enabling the switching of the flow path connecting the inlet throttle valve 5 and the actuator 8. Specifically, the inlet throttle valve 5 can be switched to any of the following positions: a first connection position 5X, outputting working fluid from the working fluid source 2 to the first fluid pressure chamber 8a via flow path 11b, flow path 11a, and the first port P1; a blocking position 5Y, blocking the output of working fluid to each fluid pressure chamber 8a, 8b; and a second connection position 5Z, outputting working fluid from the working fluid source 2 to the second fluid pressure chamber 8b via flow path 11e, flow path 11d, and the second port P2. In the illustrated embodiment, the inlet throttle valve 5 is switched to the first connected position 5X by pilot pressure from the first electromagnetic proportional valve 31, and to the second connected position 5Z by pilot pressure from the second electromagnetic proportional valve 32.

[0044] The inlet throttle valve 5 is provided with a flow path connecting flow path 12a and flow path 11b or flow path 12a and flow path 11e, and flow path 12a is connected to the working fluid source 2. When the inlet throttle valve 5 is switched to the first connected position 5X, the flow path of the inlet throttle valve 5 is connected to flow path 11b, opening the flow path from the working fluid source 2 to the first fluid pressure chamber 8a, and working fluid is output to the first fluid pressure chamber 8a through this flow path. When the inlet throttle valve 5 is switched to the second connected position 5Z, the flow path of the inlet throttle valve 5 is connected to flow path 11e, opening the flow path from the working fluid source 2 to the second fluid pressure chamber 8b, and working fluid is output to the second fluid pressure chamber 8b through this flow path. The opening area of ​​the flow path through which the working fluid in the inlet throttle valve 5 passes varies depending on the axial position of the valve stem of the inlet throttle valve. The axial position of the inlet throttle valve stem is adjusted by a first pilot pressure or a second pilot pressure output to the pilot pressure chamber of the inlet throttle valve 5. This allows the inlet throttle valve 5 to selectively output working fluid from the working fluid source 2 to either the first fluid pressure chamber 8a or the second fluid pressure chamber 8b at a flow rate corresponding to the opening area of ​​the flow path within the inlet throttle valve 5, which varies according to the axial position of the inlet throttle valve stem. The opening area of ​​the flow path through which the working fluid passes in the inlet throttle valve 5 is adjusted by shifting the axial position of the inlet throttle valve stem by adjusting the first or second pilot pressure. Thus, the inlet throttle valve 5 can output working fluid to the actuator 8 at a flow rate corresponding to the first or second pilot pressure.

[0045] An outlet throttle valve 6 is disposed between the actuator 8 and the tank 3. The first fluid pressure chamber 8a of the actuator 8 is connected to the outlet throttle valve 6 via a first port P1, flow path 11a, and flow path 11c. The second fluid pressure chamber 8b of the actuator 8 is connected to the outlet throttle valve 6 via a second port P2, flow path 11d, and flow path 11f. Additionally, the outlet throttle valve 6 is also connected to the switching mechanism 20 to receive pilot pressure. Specifically, the outlet throttle valve 6 is connected to the switching mechanism 20 via flow path 13c and flow path 13f. The outlet throttle valve 6 has at least one pilot pressure chamber. Depending on the switching mechanism 20, pilot pressure is output from either the first electromagnetic proportional valve 31 or the second electromagnetic proportional valve 32 to this at least one pilot pressure chamber of the outlet throttle valve 6.

[0046] The outlet throttle valve 6, like the inlet throttle valve 5, has a valve stem that is housed within the internal space of the manifold. The valve stem of the outlet throttle valve 6 is sometimes referred to as the outlet throttle valve stem. The outlet throttle valve 6 is configured such that the valve stem is axially displaced by pilot pressure from either the solenoid proportional valve 31 or the second solenoid proportional valve 32, thereby enabling the switching of the flow path connecting the outlet throttle valve 6 and the actuator 8. Specifically, the outlet throttle valve 6 can be switched to any of the following positions: a first discharge position 6X, discharging working fluid from the first fluid pressure chamber 8a to the tank 3 via the first port P1, flow path 11a, flow path 11c, and flow path 12b; a blocking position 6Y, blocking the discharge of working fluid from each of the fluid pressure chambers 8a and 8b; and a second discharge position 6Z, discharging working fluid from the second fluid pressure chamber 8b to the tank 3 via the second port P2, flow path 11d, flow path 11f, and flow path 12b. In the illustrated embodiment, the outlet throttle valve 6 is switched to the first discharge position 6X by means of the pilot pressure from the first electromagnetic proportional valve 31, and to the second discharge position 6Z by means of the pilot pressure from the second electromagnetic proportional valve 32.

[0047] The outlet throttle valve 6 is provided with a flow path connecting flow path 12b and flow path 11c or flow path 12b and flow path 11f, and flow path 12b is connected to tank 3. When the outlet throttle valve 6 is switched to the first discharge position 6X, the flow path of the outlet throttle valve 6 is connected to flow path 11c, opening the flow path from the first fluid pressure chamber 8a to tank 3, through which working fluid is discharged from the first fluid pressure chamber 8a. When the outlet throttle valve 6 is switched to the second discharge position 6Z, the flow path of the outlet throttle valve 6 is connected to flow path 11f, opening the flow path from the second fluid pressure chamber 8b to tank 3, through which working fluid is discharged from the second fluid pressure chamber 8b. The opening area of ​​the flow path through which the working fluid in the outlet throttle valve 6 passes varies depending on the axial position of the outlet throttle valve stem. The axial position of the outlet throttle valve stem is adjusted by a first pilot pressure or a second pilot pressure output to the pilot pressure chamber of the outlet throttle valve 6. This allows the outlet throttle valve 6 to selectively discharge working fluid from the working fluid source 2 at a flow rate corresponding to the opening area of ​​the flow path within the outlet throttle valve 6, which varies according to the axial position of the outlet throttle valve stem. The opening area of ​​the flow path through which the working fluid passes in the outlet throttle valve 6 is adjusted by shifting the axial position of the outlet throttle valve stem by adjusting the first or second pilot pressure. Thus, the outlet throttle valve 6 can discharge working fluid from the actuator 8 at a flow rate corresponding to the first or second pilot pressure.

[0048] The switching mechanism 20 is configured to switch the flow paths between the first solenoid proportional valve 31 and the second solenoid proportional valve 32 and the inlet throttle valve 5 and the outlet throttle valve 6, thereby outputting a first pilot pressure from the first solenoid proportional valve 31 to one of the inlet throttle valve 5 and the outlet throttle valve 6, and outputting a second pilot pressure from the second solenoid proportional valve 32 to the other of the inlet throttle valve 5 and the outlet throttle valve 6. Specifically, when the switching mechanism 20 outputs the first pilot pressure from the first solenoid proportional valve 31 to the inlet throttle valve 5, it outputs the second pilot pressure from the second solenoid proportional valve 32 to the outlet throttle valve 6. Conversely, when the switching mechanism 20 outputs the first pilot pressure from the first solenoid proportional valve 31 to the outlet throttle valve 6, it outputs the second pilot pressure from the second solenoid proportional valve 32 to the inlet throttle valve 5. As explained in detail below, the switching of the flow path by the switching mechanism 20 is based on at least one of the first pilot pressure, the second pilot pressure, and the movement of the outlet throttle valve 6 (the position of the outlet throttle valve 6).

[0049] The switching mechanism 20 includes a first selector valve 21 and a second selector valve 22. The first selector valve 21 is connected to a first solenoid proportional valve 31 via flow path 13a, to an inlet throttle valve 5 via flow path 13b, and to an outlet throttle valve 6 via flow path 13c. The first selector valve 21 is switched to either a first position 21X that outputs a first pilot pressure from the first solenoid proportional valve 31 to the outlet throttle valve 6, or a second position 21Y that outputs a first pilot pressure from the first solenoid proportional valve 31 to the inlet throttle valve 5. Both the first selector valve 21 and the second selector valve 22 can be known selector valves.

[0050] The second selector valve 22 is connected to the second solenoid proportional valve 32 via flow path 13d, to the inlet throttle valve 5 via flow path 13e, and to the outlet throttle valve 6 via flow path 13f. The second selector valve 22 is switched to either a third position 22X that outputs the second pilot pressure from the second solenoid proportional valve 32 to the inlet throttle valve 5, or a fourth position 22Y that outputs the second pilot pressure from the second solenoid proportional valve 32 to the outlet throttle valve 6.

[0051] When the first electromagnetic proportional valve 31 is energized while the second electromagnetic proportional valve 32 is not energized, the first selector valve 21 is switched to the first position 21X by receiving the first pilot pressure from the first electromagnetic proportional valve 31. When the second electromagnetic proportional valve 32 is not energized, the second pilot pressure is not output from the second electromagnetic proportional valve 32 to the switching mechanism 20. That is, when the first pilot pressure is output from the first electromagnetic proportional valve 31 while the second pilot pressure is not output from the second electromagnetic proportional valve 32, the first selector valve 21 switches to the first position 21X. The first selector valve 21 has a pusher 21a connected to the outlet throttle valve 6. If the outlet throttle valve 6 is switched to the second discharge position 6Z while the first pilot pressure is not output to the first selector valve 21, the pusher 21a is pushed inwards into the first selector valve 21. If pusher 21a is pushed inwards towards the first selector valve 21, the first selector valve 21 is switched to the second position 21Y. Even while the first pilot pressure is being output to the first selector valve 21, a second pilot pressure is output from the second solenoid proportional valve 32 to the switching mechanism 20, the first selector valve 21 remains in the first position 21X, and the second selector valve 22 remains in the third position 22X. In other words, the first pilot pressure from the first solenoid proportional valve 31 locks the first selector valve 21 in the first position 21X and the second selector valve 22 in the third position 22X.

[0052] When the first electromagnetic proportional valve 31 is not energized while the second electromagnetic proportional valve 32 is energized, the second selector valve 22 is switched to position 4 22Y by receiving a second pilot pressure from the second electromagnetic proportional valve 32. When the first electromagnetic proportional valve 31 is not energized, the first pilot pressure is not output from the first electromagnetic proportional valve 31 to the switching mechanism 20. That is, when the second pilot pressure is output from the second electromagnetic proportional valve 32 while the first pilot pressure is not output from the first electromagnetic proportional valve 31, the second selector valve 22 switches to position 4 22Y. The second selector valve 22 has a pusher 22a connected to the outlet throttle valve 6. If the outlet throttle valve 6 is switched to the first discharge position 6X while the second pilot pressure is not output to the second selector valve 22, the pusher 22a is pushed inwards into the second selector valve 22. If pusher 22a is pushed inwards towards the second selector valve 22, the second selector valve 22 is switched to the third position 22X. Even while the second pilot pressure is being output to the second selector valve 22, the first pilot pressure is being output from the first solenoid proportional valve 31 to the switching mechanism 20, the second selector valve 22 remains in the fourth position 22Y, and the first selector valve 21 remains in the second position 21Y. In other words, the second pilot pressure from the second solenoid proportional valve 32 locks the second selector valve 22 in the fourth position 22Y and the first selector valve 21 in the second position 21Y.

[0053] Next, further reference Figure 2a , Figure 2b , Figure 3a ,as well as Figure 3b The operation of the actuator control device 1 will be explained. Assume that at the start of operation, neither the first solenoid proportional valve 31 nor the second solenoid proportional valve 32 is energized; therefore, no pilot pressure is output from either the first solenoid proportional valve 31 or the second solenoid proportional valve 32. In this case, if... Figure 1 As shown, the inlet throttle valve 5 is in the blocked position 5Y, and the outlet throttle valve 6 is in the blocked position 6Y. Additionally, the first selector valve 21 and the second selector valve 22 are not locked.

[0054] Reference Figure 2a and Figure 2b The action of retracting the actuator 8 will be explained. When the actuator 8 is retracted, the controller 10 energizes the first solenoid proportional valve 31. As a result, the first solenoid proportional valve 31 opens, and a first pilot pressure is output from the first solenoid proportional valve 31 to the first selector valve 21 of the switching mechanism 20. This first pilot pressure is used to switch the first selector valve 21 to the first position 21X.

[0055] The first selector valve 21 is switched to the first position 21X, thereby outputting the first pilot pressure to the outlet throttle valve 6. For example... Figure 2aAs shown, the first pilot pressure switches the outlet throttle valve 6 to the first discharge position 6X. This opens the flow path from the first fluid pressure chamber 8a of the actuator 8 through flow path 11a, flow path 11c, and flow path 12b to the tank 3. Furthermore, since the outlet throttle valve 6 is switched to the first discharge position 6X, pusher 22a is pushed into the interior of the second selector valve 22, thereby switching the second selector valve 22 to the third position 22X.

[0056] Next, while maintaining the first solenoid proportional valve 31 in the energized state, the controller 10 energizes the second solenoid proportional valve 32, thereby opening the second solenoid proportional valve 32. Since the second selector valve 22 is switched to the third position 22X, a second pilot pressure from the second solenoid proportional valve 32 is output to the inlet throttle valve 5. Figure 2b As shown, the inlet throttle valve 5 is switched to the second connected position 5Z by the second pilot pressure from the second electromagnetic proportional valve 32. As a result, the flow path from the working fluid source 2 through flow path 12a, flow path 11e and flow path 11d to the second fluid pressure chamber 8b of the actuator 8 is opened.

[0057] In this way, working fluid is supplied to the second fluid pressure chamber 8b of the actuator 8 and working fluid is discharged from the first fluid pressure chamber 8a, thus enabling the actuator 8 to contract.

[0058] Next, refer to Figure 3a and Figure 3b The action that extends actuator 8 will be explained. (As shown in the example...) Figure 2b When both the first electromagnetic proportional valve 31 and the second electromagnetic proportional valve 32 are energized as shown, the actuator 8 extends. In this case, the controller 10 stops the energization of the first electromagnetic proportional valve 31 and the second electromagnetic proportional valve 32, thereby releasing the locking of the first selector valve 21 and the second selector valve 22. The controller 10 then energizes the second electromagnetic proportional valve 32, causing it to open. As a result, a second pilot pressure is output from the second electromagnetic proportional valve 32 to the second selector valve 22 of the switching mechanism 20. This second pilot pressure is used to switch the second selector valve 22 to the fourth position 22Y.

[0059] The second selector valve 22 is switched to position 4 22Y, thereby outputting the second pilot pressure to the outlet throttle valve 6. Figure 3a As shown, the second pilot pressure switches the outlet throttle valve 6 to the second discharge position 6Z. This opens the flow path from the second fluid pressure chamber 8b of the actuator 8 through flow path 11d, flow path 11f, and flow path 12b to the tank 3. Furthermore, since the outlet throttle valve 6 is switched to the second discharge position 6Z, pusher 21a is pushed into the first selector valve 21, thereby switching the first selector valve 21 to the second position 21Y.

[0060] Next, while maintaining the energized state of the second electromagnetic proportional valve 32, the controller 10 energizes the first electromagnetic proportional valve 31, thereby opening the first electromagnetic proportional valve 31. Since the first selector valve 21 is switched to the second position 21Y, a first pilot pressure from the first electromagnetic proportional valve 31 is output to the inlet throttle valve 5. Figure 3b As shown, the inlet throttle valve 5 is switched to the first connected position 5X by the first pilot pressure from the first electromagnetic proportional valve 31. As a result, the flow path from the working fluid source 2 through flow path 12a, flow path 11b and flow path 11a to the first fluid pressure chamber 8a of the actuator 8 is opened.

[0061] In this way, working fluid is supplied to the first fluid pressure chamber 8a of the actuator 8 and discharged from the second fluid pressure chamber 8b, thus enabling the actuator 8 to extend.

[0062] The movement speed of piston 8c during the contraction and extension of actuator 8 is controlled by the opening area of ​​the working fluid flow path in inlet throttle valve 5 and outlet throttle valve 6. As described above, these opening areas can be adjusted using a first pilot pressure and a second pilot pressure. Thus, by adjusting the opening areas of the working fluid flow path in inlet throttle valve 5 and outlet throttle valve 6 using the control of the first pilot pressure and the second pilot pressure, inlet throttling control is performed to adjust the flow rate of working fluid output from working fluid source 2 to actuator 8 via inlet throttle valve 5, and outlet throttling control is performed to adjust the flow rate of working fluid discharged from actuator 8 to tank 3 via outlet throttle valve 6 during operation of actuator 8.

[0063] Next, refer to Figure 4 An actuator control device 101 according to another embodiment of the present invention will be described. The actuator control device 101 according to another embodiment of the present invention differs from actuator control device 1 in that it has two working fluid sources and that the supply of working fluid from these two working fluid sources is controlled by an inlet throttle valve 105. Figure 4 The components of the actuator control device 101 shown are related to Figure 1 The components of the actuator control device 1 shown are the same as or similar to those shown. Figure 1 The same or similar reference numerals are used in the accompanying drawings, and detailed descriptions of these constituent elements are omitted.

[0064] As shown in the figure, the actuator control device 101 includes a working fluid source 2 and a working fluid source 102. The working fluid source 102 is connected to the inlet throttle valve 105 via a flow path 112a. A check valve 104 for maintaining negative pressure is provided in the flow path 112a.

[0065] An inlet throttle valve 105 is disposed between the actuator 8 and the working fluid source 2 and the working fluid source 102. The working fluid source 2 and the working fluid source 102 are configured in parallel with respect to the inlet throttle valve 105.

[0066] The inlet throttle valve 105 is configured to have an inlet throttle valve stem, which is displaced by pilot pressure from the solenoid proportional valve 31 or the second solenoid proportional valve 32, thereby enabling the switching of the path of the working fluid connecting the inlet throttle valve 105 and the actuator 8. Specifically, the inlet throttle valve 105 can be switched to any of the following positions: a first connection position 105X, which outputs working fluid from the working fluid source 2 to the first fluid pressure chamber 8a via flow path 11b, flow path 11a and the first port P1; a blocking position 105Y, which blocks the output of working fluid to each fluid pressure chamber 8a, 8b; and a second connection position 105Z, which outputs at least one of the working fluid from the working fluid source 2 and the working fluid source 102 to the second fluid pressure chamber 8b via flow path 11e, flow path 11d and the second port P2. In the illustrated embodiment, the inlet throttle valve 105 switches to the first connected position 105X using a first pilot pressure from the first solenoid proportional valve 31, and switches to the second connected position 105Z using a second pilot pressure from the second solenoid proportional valve 32. The second connected position 105Z is divided into a second single-connection position 105Z1, which outputs working fluid from only working fluid source 2 (one of the parallel-configured working fluid sources 2 and 102) to the second fluid pressure chamber 8b, and a second double-connection position 105Z2, which outputs working fluid from both working fluid source 2 and working fluid source 102 to the second fluid pressure chamber 8b. Alternatively, the inlet throttle valve 105 may switch to the second single-connection position 105Z1 when the second pilot pressure is lower than a predetermined reference pressure, and switch to the second double-connection position 105Z2 when the second pilot pressure is higher than the predetermined reference pressure.

[0067] In the illustrated embodiment, the inlet throttle valve 105 may also be configured to output working fluid from both working fluid source 2 and working fluid source 102 to the first fluid pressure chamber 8a. For example, the first connection position 105X may be divided into a first single connection position that outputs working fluid from only working fluid source 2 of the parallel-configured working fluid source 2 and working fluid source 102 to the first fluid pressure chamber 8a, and a first multiple connection position that outputs working fluid from both working fluid source 2 and working fluid source 102 to the first fluid pressure chamber 8a. Alternatively, the inlet throttle valve 105 may switch to the first single connection position when the first pilot pressure is lower than a predetermined reference pressure, and switch to the first multiple connection position when the first pilot pressure is higher than the predetermined reference pressure.

[0068] The actuator control device 101 operates in substantially the same manner as the actuator control device 1. When the inlet throttle valve 105 is switched to the second reconnection position 105Z2, the controller 10 energizes the second electromagnetic proportional valve 32 so that the second pilot pressure is above a predetermined reference value.

[0069] Next, the effects of the above-described embodiments will be explained. The actuator control devices 1 and 101 of the above embodiments enable the switching mechanism 20 to selectively output a first pilot pressure from the first electromagnetic proportional valve 31 and a second pilot pressure from the second electromagnetic proportional valve 32 to the inlet throttle valves 5 and 105 and the outlet throttle valve 6, thereby switching the flow path between the actuator 8 and the inlet throttle valves 5 and 105 / outlet throttle valve 6. Thus, according to the actuator control device 1, inlet throttling control and outlet throttling control of the actuator 8 can be achieved by controlling these two pilot pressures, the first pilot pressure and the second pilot pressure. More specifically, in the above embodiments, inlet throttling control and outlet throttling control of the actuator 8 can be achieved using two valve stems (the inlet throttle valve stems of the inlet throttle valves 5 and 105 and the outlet throttle valve stems of the outlet throttle valve 6) and two electromagnetic pilot valves 31 and 32. Therefore, the actuator control devices 1 and 101 according to the above embodiments can perform inlet throttling and outlet throttling control with a simpler structure compared to conventional IMV actuator control devices that use four valve stems (two inlet throttling valve stems and two outlet throttling valve stems) and four electromagnetic proportional valves for inlet throttling control and outlet throttling control.

[0070] According to the above embodiment, the switching mechanism 20 can be implemented using the first selection valve 21 and the second selection valve 22. Both the first selection valve 21 and the second selection valve 22 can be configured as two-position valves with a simple structure that allows switching between two positions. Therefore, according to the above embodiment, the switching mechanism 20 for the actuator control device can be implemented with a simple structure.

[0071] According to the above-described embodiment, when the second pilot pressure is not output from the second electromagnetic proportional valve 32 to the switching mechanism 20, the first electromagnetic proportional valve 31 is controlled to output the first pilot pressure to the switching mechanism 20, thereby switching the first selector valve 21 to the first position 21X and the second selector valve 22 to the third position 22X. Thus, the switching of the switching mechanism 20 can be performed using control of the first electromagnetic proportional valve 31.

[0072] According to the above-described embodiment, when the first pilot pressure is not output from the first electromagnetic proportional valve 31 to the switching mechanism 20, the second electromagnetic proportional valve 32 is controlled to output a second pilot pressure to the switching mechanism 20, thereby switching the first selector valve 21 to the second position 21Y and the second selector valve 22 to the fourth position 22Y. Thus, the switching of the switching mechanism 20 can be performed using control of the second electromagnetic proportional valve 31.

[0073] According to the above-described embodiment, working fluid can be output to the actuator 8 at a flow rate corresponding to the first pilot pressure or the second pilot pressure. Therefore, inlet throttling control can be performed by controlling the two electromagnetic proportional valves, the first electromagnetic proportional valve 31 and the second electromagnetic proportional valve 32.

[0074] According to the above-described embodiment, working fluid can be discharged from the actuator 8 at a flow rate corresponding to the first pilot pressure or the second pilot pressure. Therefore, outlet throttling control can be performed by controlling the two electromagnetic proportional valves, the first electromagnetic proportional valve 31 and the second electromagnetic proportional valve 32.

[0075] According to one embodiment described above, in order to drive the actuator 8, working fluid from two working fluid sources 2 and 102 can be used independently.

[0076] The dimensions, materials, and configurations of the constituent elements described in this specification are not limited to those explicitly described in the embodiments. These constituent elements can be modified to have any dimensions, materials, and configurations that fall within the scope of this invention. Furthermore, constituent elements not explicitly described in this specification can be added to the described embodiments, and some constituent elements described in each embodiment can be omitted.

[0077] The inlet throttle valve 5, outlet throttle valve 6, first selector valve 21, second selector valve 22, first electromagnetic proportional valve 31, and second electromagnetic proportional valve 32 can be installed in a single manifold (or valve body) or distributed across multiple manifolds. When these valves are distributed across multiple manifolds, the actuator control device 1, 101 is fabricated by assembling these multiple manifolds.

Claims

1. An actuator control device, wherein, The actuator control device includes: The outlet throttle valve discharges working fluid from the first fluid pressure chamber of the actuator to the tank using a first pilot pressure or a second pilot pressure; An inlet throttle valve that outputs the working fluid from the working fluid source to the second fluid pressure chamber of the actuator using the first pilot pressure or the second pilot pressure; as well as A switching mechanism that switches based on at least one of the first pilot pressure and the second pilot pressure to output one of the first pilot pressure and the second pilot pressure to the outlet throttle valve and the other of the first pilot pressure and the second pilot pressure to the inlet throttle valve.

2. The actuator control device according to claim 1, wherein, The switching mechanism switches by moving the outlet throttle valve.

3. The actuator control device according to claim 1 or 2, wherein, The switching mechanism includes: a first selector valve, which can be switched to a first position to output the first pilot pressure to the outlet throttle valve or a second position to output the first pilot pressure to the inlet throttle valve; and a second selector valve, which can be switched to a third position to output the second pilot pressure to the inlet throttle valve or a fourth position to output the second pilot pressure to the outlet throttle valve.

4. The actuator control device according to claim 3, wherein, The switching mechanism switches the first selector valve to the first position and the second selector valve to the third position when the first pilot pressure is received even when the second pilot pressure is not supplied.

5. The actuator control device according to claim 3, wherein, The switching mechanism switches the first selector valve to the second position and the second selector valve to the fourth position when the second pilot pressure is received even when the first pilot pressure is not supplied.

6. The actuator control device according to any one of claims 1 to 5, wherein, The inlet throttle valve outputs the working fluid to the actuator according to the first pilot pressure or the second pilot pressure.

7. The actuator control device according to any one of claims 1 to 6, wherein, The outlet throttle valve discharges the working fluid from the actuator according to the first pilot pressure or the second pilot pressure.

8. The actuator control device according to any one of claims 1 to 7, wherein, The inlet throttle valve is located between the actuator and the first working fluid source and the second working fluid source.

9. The actuator control device according to claim 8, wherein, The inlet throttle valve switches between the following positions: a position where the working fluid is output to the actuator from either the first working fluid source or the second working fluid source; and a position where the working fluid is output to the actuator from both the first working fluid source and the second working fluid source.

10. An actuator control device, wherein, The actuator control device includes: First electromagnetic proportional valve; Second electromagnetic proportional valve; The outlet throttle valve switches to a first discharge position using a first pilot pressure output from the first electromagnetic proportional valve, in which working fluid is discharged from the first fluid pressure chamber of the actuator to the tank. It also switches to a second discharge position using a second pilot pressure output from the second electromagnetic proportional valve, in which working fluid is discharged from the second fluid pressure chamber of the actuator to the tank. An inlet throttle valve is switched to a first connected position by the first pilot pressure, in which working fluid from a working fluid source is supplied to the first fluid pressure chamber of the actuator, and switched to a second connected position by the second pilot pressure, in which working fluid from a working fluid source is supplied to the second fluid pressure chamber of the actuator. as well as A switching mechanism includes: a first selector valve capable of switching to a first position supplying the first pilot pressure to the outlet throttle valve or a second position supplying the first pilot pressure to the inlet throttle valve; and a second selector valve capable of switching to a third position supplying the second pilot pressure to the inlet throttle valve or a fourth position supplying the second pilot pressure to the outlet throttle valve. The switching mechanism utilizes movement of the outlet throttle valve to switch the first selector valve from the first position to the second position or the second selector valve from the fourth position to the third position.

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