Fluid pressure cylinder drive device

Abstract

The present invention provides a fluid pressure cylinder drive device that can further reduce fluid consumption and simplify its configuration. [Solution] When moving the piston M2 to the side of the first cylinder chamber M4, the second switching valve 21 is controlled to the supply source shut-off second switching state, causing the first switching valve 14 to enter the second flow path communication first switching state, and the first control flow path 18 to open, causing the second flow path switching valve 17 to enter the normal second flow path communication state, thus connecting the first flow path 12 and the second flow path 13. Furthermore, when the fluid pressure in the second flow path 13 exceeds a predetermined value, the regulator 20 supplies fluid to the side of the second control flow path 19 to the first flow path switching valve 16, causing the first flow path switching valve 16 to enter the first flow path shut-off state, and opening the side of the first flow path 12 to the first cylinder chamber M4.

Description

Technical Field

[0001] The present invention relates to a fluid pressure cylinder driving device for driving a fluid pressure cylinder in which the inside of a cylinder body is partitioned into a first cylinder chamber and a second cylinder chamber by a piston.

Background Art

[0002] As a driving device for a fluid pressure cylinder, for example, at the time of extrusion, fluid is supplied from a supply source to one cylinder chamber in the fluid pressure cylinder, and fluid is discharged from the other cylinder chamber to the outside. At the time of retraction, a part of the fluid accumulated in one cylinder chamber is supplied to the other cylinder chamber to move the piston a predetermined distance in the other direction, and then fluid is supplied from the supply source to the other cylinder chamber to move the piston further in the other direction, and fluid is discharged from one cylinder chamber to the outside (see, for example, Patent Document 1).

[0003] According to this driving device, at the time of retraction, since the piston is moved by using the fluid exhausted from one cylinder chamber, the fluid consumption can be reduced as compared with the case of moving only by the fluid from the supply source. Further, at the time of retraction, simultaneously with the start of the movement of the piston, the fluid from one cylinder chamber can be supplied to the other cylinder chamber to increase the pressure and decrease the pressure in one cylinder chamber, so that the return operation of the piston can be performed quickly.

[0004] However, in the driving device of Patent Document 1, in order to complete the return operation at the time of retraction, it is necessary to supply fluid from a supply source, and there is a problem that the fluid consumption cannot be sufficiently reduced. Further, in the driving device of Patent Document 1, since the switching of the operation is performed by electric control, each switching valve has to be controlled, and there is a problem that the configuration is complicated.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Patent No. 6467733 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] The present invention has been made in response to these problems and aims to provide a fluid pressure cylinder drive device that can further reduce fluid consumption and simplify its configuration. [Means for solving the problem]

[0007] The fluid pressure cylinder drive device of the present invention drives a fluid pressure cylinder in which the inside of the cylinder body is divided into a first cylinder chamber and a second cylinder chamber by a piston, and comprises a supply source that supplies fluid to the fluid pressure cylinder, a first flow path that connects the supply source to the first cylinder chamber, a second flow path that branches off from the first flow path and connects the first flow path to the second cylinder chamber, and a device disposed at the branching point between the first flow path and the second flow path that connects the supply source side of the first flow path to the first cylinder chamber side, and the second flow path and the first flow path A first switching valve switches between a supply source side communication first switching state in which communication is blocked and a second flow path communication first switching state in which communication between the supply source side and the first cylinder chamber side of the first flow path is blocked and the second flow path is connected to the first cylinder chamber side of the first flow path; a first flow path switching valve is disposed on the first cylinder chamber side of the first flow path and switches between a first flow path connection state in which the first flow path is connected and a first flow path blocking state in which the first switching valve side of the first flow path is closed and the first cylinder chamber side is open; and a second switching valve is disposed in the second flow path and connects the second flow path. A second flow path switching valve switches between a second flow path communication state and a second flow path blocking state, which closes the first switching valve side of the second flow path and opens the second cylinder chamber side, making the second flow path communication state the normal state; a first control flow path that branches off from the first flow path on the supply source side of the first switching valve and controls the first flow path switching valve to be in the first flow path communication state and controls the second flow path switching valve to be in the second flow path blocking state; and a second flow path that branches off from the second flow path on the second cylinder chamber side of the second flow path switching valve and controls the first flow path The system includes a second control channel that controls the switching valve to a first channel blocking state, a regulator disposed in the second control channel that supplies fluid to the first channel switching valve side when the fluid pressure in the second channel is above a predetermined value and puts the first channel switching valve into a first channel blocking state, and a second switching valve disposed on the supply source side of the branch of the first control channel in the first channel that switches between a supply source communication second switching state that connects to the supply source and a supply source blocking second switching state that blocks communication with the supply source and opens the first control channel. [Effects of the Invention]

[0008] According to the present invention, for example, when moving the piston to the side of the second cylinder chamber, the two switching valves are set to the second switching state for supply source communication, the first switching valve is set to the first switching state for supply source side communication, the first flow path switching valve is set to the first flow path communication state via the first control flow path, and the second flow path switching valve is set to the second flow path blocking state, thereby connecting the supply source to the first cylinder chamber and opening the second cylinder chamber side of the second flow path.

[0009] Furthermore, when moving the piston towards the first cylinder chamber, the second switching valve is set to the supply source shut-off second switching state, and the first switching valve is set to the second flow path communication first switching state, opening the first control flow path and setting the second flow path switching valve to the normal second flow path communication state, thus connecting the first and second flow paths. Additionally, when the fluid pressure in the second flow path exceeds a predetermined value, the regulator supplies fluid to the first flow path switching valve side of the second control flow path, setting the first flow path switching valve to the first flow path shut-off state and opening the first cylinder chamber side of the first flow path. Thus, the piston can be returned using only the fluid supplied to the first cylinder chamber, further reducing fluid consumption.

[0010] Furthermore, since the first flow path switching valve and the second flow path switching valve are controlled using fluid supplied from the supply source via the first control flow path or the second control flow path, there is no need for individual electrical control, and the configuration can be simplified.

[0011] Furthermore, by utilizing the fact that the pressure on the supply source side of the first switching valve changes depending on the switching state of the second switching valve, the first switching valve can be switched, allowing the entire system to be driven by controlling only the second switching valve. [Brief explanation of the drawing]

[0012] [Figure 1] This figure shows the configuration of a fluid pressure cylinder drive device according to one embodiment of the present invention. [Figure 2] Another diagram illustrating the configuration of the fluid pressure cylinder drive device shown in Figure 1. [Figure 3] This is yet another diagram illustrating the configuration of the fluid pressure cylinder drive device shown in Figure 1. [Figure 4] This is yet another diagram illustrating the configuration of the fluid pressure cylinder drive device shown in Figure 1. [Figure 5] This is yet another diagram illustrating the configuration of the fluid pressure cylinder drive device shown in Figure 1. [Modes for carrying out the invention]

[0013] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0014] Figures 1 to 5 show the configuration of a fluid pressure cylinder drive device 10 according to one embodiment of the present invention. This fluid pressure cylinder drive device 10 drives a double-acting fluid pressure cylinder M. Figures 1 and 2 show the configuration during the drive operation of the fluid pressure cylinder M, and Figures 3 to 5 show the configuration during the return operation of the fluid pressure cylinder M.

[0015] The fluid pressure cylinder M comprises, for example, a hollow cylinder body M1, a piston M2 reciprocally mounted inside the cylinder body M1, and a piston rod M3 connected to the piston M2, with the other end of the piston rod M3 protruding from the cylinder body M2 and exposed to the outside. The inside of the cylinder body M1 is divided into a first cylinder chamber M4 and a second cylinder chamber M5 by the piston M2. The first cylinder chamber M4 is, for example, a head-side cylinder chamber located between one end of the cylinder body M1 and the piston M2, and the second cylinder chamber M5 is, for example, a rod-side cylinder chamber formed between the other end of the cylinder body M1 and the piston M2, in which the piston rod M3 is housed.

[0016] In the fluid pressure cylinder M, for example, when a fluid such as air is supplied to the first cylinder chamber M4 during the pushing operation (driving operation), the piston rod M3 moves to the other end of the cylinder body M1 together with the piston M2, that is, the piston M2 moves to the side of the second cylinder chamber M5, and the piston rod M3 protrudes outward from the cylinder body M1. Also, for example, when a fluid such as air is supplied to the second cylinder chamber M5 during the retraction operation (return operation), the piston rod M3 moves to the one end of the cylinder body M1 together with the piston M2, that is, the piston M2 moves to the side of the first cylinder chamber M4, and the piston rod M3 is retracted into the cylinder body M1.

[0017] The fluid pressure cylinder drive device 10 includes a supply source 11 that supplies fluid such as air to the fluid pressure cylinder M, a first flow path 12 that connects the supply source 11 to the first cylinder chamber M4, a second flow path 13 that branches off from the first flow path 12 and connects the first flow path 12 to the second cylinder chamber M5, and a first switching valve 14 disposed at the branching point between the first flow path 12 and the second flow path 13.

[0018] The first switching valve 14 switches between a first switching state where the supply source 11 side of the first flow path 12 is connected to the first cylinder chamber M4 side and communication between the second flow path 13 and the first flow path 12 is blocked, and a first switching state where the supply source 11 side of the first flow path 12 is blocked from communication between the supply source 11 side of the first flow path 12 and the first cylinder chamber M4 side and the second flow path 13 is connected to the first cylinder chamber M4 side of the first flow path 12. Preferably, the first switching valve 14 is configured as a high-speed exhaust valve (check valve) that autonomously (automatically) switches between the first switching state of supply source side and the first switching state of second flow path connection by utilizing the change in pressure on the supply source 11 side of the first switching valve 14 due to the switching state of the second switching valve 21, which will be described later.

[0019] Specifically, for example, when the second switching valve 21 described later is in the supply source communication second switching state in which it communicates with the supply source, the communication between the second flow path 13 and the first flow path 12 is blocked by the pressure from the supply source 11, and the side of the supply source 11 of the first flow path 12 communicates with the side of the first cylinder chamber M4. Further, when the second switching valve 21 blocks the communication with the supply source 11 and is in the supply source blocking second switching state in which the side of the first switching valve 14 of the first flow path 12 is opened, the residual pressure between the supply source 11 and the first switching valve 14 of the first flow path 12 is discharged, and the pressure between the first switching valve 14 and the first flow path switching valve 16 of the first flow path 12 blocks the communication between the side of the supply source 11 of the first flow path 12 and the side of the first cylinder chamber M4, and it is preferable that the first flow path 12 and the second flow path 13 are configured to communicate with each other.

[0020] The fluid pressure cylinder drive device 10 further includes a first flow path switching valve 16 disposed on the side of the first cylinder chamber M4 rather than the first switching valve 14 in the first flow path 12, and a second flow path switching valve 17 disposed in the second flow path 13.

[0021] The first flow path switching valve 16 switches between a first flow path communication state in which the first flow path 12 is communicated, and a first flow path blocking state in which the side of the first switching valve 14 in the first flow path switching valve 16 of the first flow path 12 is closed and connected to an exhaust port 16A that communicates the side of the first cylinder chamber M4 to the outside and is opened. The first flow path switching valve 16 is configured to control the switching between, for example, the first flow path communication state and the first flow path blocking state by a fluid such as air. The first flow path switching valve 16 can be configured by, for example, an air-operated valve.

[0022] The second flow path switching valve 17 switches between a second flow path connected state, which connects to the second flow path 13, and a second flow path blocked state, which closes the side of the second flow path 13 on the first switching valve 14 side of the second flow path 13 in the second flow path switching valve 17, and opens the side of the second cylinder chamber M5 to the exhaust port 17A which communicates with the outside. The second flow path switching valve 17 is configured so that the second flow path connected state is the normal state, and the switching between the second flow path connected state and the second flow path blocked state is controlled by a fluid such as air. Specifically, it is preferable that the second flow path switching valve 17 is biased by a biasing means 17B or the like so that when operated by a fluid such as air, it switches from the normal second flow path connected state to the second flow path blocked state, and when there is no operation by a fluid such as air, it returns to the normal second flow path connected state. The second flow path switching valve 17 can be configured by an air-operated valve, for example.

[0023] The fluid pressure cylinder drive device 10 further includes a first control channel 18 that controls the first channel switching valve 16 to be in a state of communication with the first channel and controls the second channel switching valve 17 to be in a state of blockage of the second channel, a second control channel 19 that controls the first channel switching valve 16 to be in a state of blockage of the first channel, and a regulator 20 disposed in the second control channel 19.

[0024] The first control channel 18 is branched from the first channel 12 on the side of the supply source 11 rather than the first switching valve 14, and is connected to the first channel switching valve 16 and the second channel switching valve 17. As a result, the first control channel 18 guides fluid from the supply source 11 to the first channel switching valve 16 and the second channel switching valve 17, causing the first channel switching valve 16 to be in a state of first channel communication and the second channel switching valve 17 to be in a state of second channel blockage.

[0025] The second control channel 19 is branched from the second channel 13 on the side of the second cylinder chamber M5, for example, from the second channel switching valve 17, and is connected to the first channel switching valve 16. As a result, the second control channel 19 guides fluid from the second channel 13 to the first channel switching valve 16, causing the first channel switching valve 16 to be in the first channel shut-off state. When the first channel switching valve 16 is in the first channel shut-off state, for example, the second control channel 19 is configured to communicate with the side of the first channel 12 that is connected to the first switching valve 14.

[0026] The regulator 20 supplies fluid to the first flow path switching valve 16 when the fluid pressure in the second flow path 13 is above a predetermined value, thereby shutting off the first flow path. The regulator 20 can be configured, for example, by a regulator. The set pressure at which the regulator 20 begins supplying fluid to the first flow path switching valve 16 is preferably above the guaranteed pressure required for the fluid pressure cylinder M to complete its return operation, and also preferably below the pressure at which the first cylinder chamber M4 and the second cylinder chamber M5 reach equilibrium by connecting the first flow path 12 and the second flow path 13. This allows for efficient control of the return operation of the fluid pressure cylinder M.

[0027] The fluid pressure cylinder drive device 10 also includes a second switching valve 21 located on the side of the supply source 11 rather than the branching point of the first control passage 18 of the first passage 12. The second switching valve 21 switches between a second switching state for supply source communication, which connects the first passage 12 to the supply source 11, and a second switching state for supply source shutdown, which shuts off communication between the first passage 12 and the supply source 11, and opens the first control passage 18 to an exhaust port 21A that communicates with the outside via the first passage 12. Furthermore, the second switching valve 21 has a control function that controls the switching state of the first switching valve 14, and by switching between the second switching state for supply source communication and the second switching state for supply source shutdown, the first switching valve 14 can be switched between a first switching state for supply source communication and a first switching state for second passage communication. Specifically, for example, by switching the second switching valve 21 to the second supply source communication switching state, the first switching valve 14 switches to the first supply source communication switching state, and by switching the second switching valve 21 to the second supply source shut-off switching state, the first switching valve switches to the first second flow path communication switching state. The second switching valve 21 can be configured, for example, as a solenoid valve that opens and closes according to a control signal from the control unit 15.

[0028] When the fluid pressure cylinder drive device 10 moves the piston M2 to the side of the second cylinder chamber M5 (during the drive operation), for example, the second switching valve 21 is controlled to the second switching state for supply source communication, causing the first switching valve 14 to enter the first switching state for supply source communication, and the first flow path switching valve 16 to enter the first flow path communication state via the first control flow path 18, while the second flow path switching valve 17 enters the second flow path blocking state, connecting the supply source 11 to the first cylinder chamber M4, and opening the second cylinder chamber M5 side of the second flow path 13 (see Figures 1 and 2). In Figures 1 and 2, the first flow path 12 and the second flow path 13 are shown with solid black lines, and the first control flow path 18 and the second control flow path 19 are shown with dashed black lines. Flow paths to which fluid is supplied are shown with a textured surface, and open flow paths are shown with a shaded surface. The same applies to Figures 3 to 5.

[0029] Furthermore, when the piston M2 is moved to the side of the first cylinder chamber M4 (during the return operation), the fluid pressure cylinder drive device 10 controls the second switching valve 21 to the supply source shut-off second switching state, causing the first switching valve 14 to enter the second flow path communication first switching state, and the first control flow path 18 to open, causing the second flow path switching valve 17 to enter the normal state of second flow path communication, thus connecting the first flow path 12 and the second flow path 13 (see Figure 3). Additionally, when the fluid pressure in the second flow path 13 exceeds a predetermined value, the regulator 20 supplies fluid to the side of the second control flow path 19 to the first flow path switching valve 16, causing the first flow path switching valve 16 to enter the first flow path shut-off state, and opening the side of the first flow path 12 to the first cylinder chamber M4 (see Figure 4).

[0030] The fluid pressure cylinder drive device 10 drives the fluid pressure cylinder M in the following manner, for example. In the fluid pressure cylinder M, the initial state is described as the state in which the piston rod M3 is most retracted into the cylinder body M1.

[0031] First, when performing a drive operation to move the piston M2 to the side of the second cylinder chamber M5 from the initial state, for example, as shown in Figure 1, the control unit 15 sets the second switching valve 21 to the second supply source communication state, thereby setting the first switching valve 14 to the first supply source side communication state. When the second switching valve 21 is set to the second supply source communication state and the first switching valve 14 is set to the first supply source side communication state, the first flow path 12 and the first control flow path 18 are connected to the supply source 11, and fluid is guided from the supply source 11 to the first flow path switching valve 16 and the second flow path switching valve 17, causing the fluid pressure in the first control flow path 18 to increase. Consequently, the first flow path switching valve 16 enters the first flow path communication state, and the second flow path switching valve 17 enters the second flow path shut-off state, the supply source 11 is connected to the first cylinder chamber M4, and the side of the second flow path 13 facing the second cylinder chamber M5 is connected to and opened by the exhaust port 17A.

[0032] As a result, in the fluid pressure cylinder M, the piston M2 is pushed and moved toward the second cylinder chamber M5 by the fluid supplied to the first cylinder chamber M4, and the fluid in the second cylinder chamber M5 is discharged from the exhaust port 17A via the second passage 13. Due to this movement of the piston M2, for example, as shown in Figure 2, the piston rod M3 is pushed out to its maximum position from the other end of the cylinder body M1 and protrudes.

[0033] Next, when performing a return operation to move the piston M2 to the side of the first cylinder chamber M4, for example, as shown in Figure 3, the control unit 15 sets the second switching valve 21 to the second supply source shut-off state, thereby setting the first switching valve 14 to the first second flow path communication state. When the second switching valve 21 is set to the second supply source shut-off state and the first switching valve 14 is set to the first second flow path communication state, the first control flow path 18 is connected to and opened at the exhaust port 21A via the first flow path 12, and the fluid pressure in the first control flow path 18 decreases. Accordingly, the second flow path switching valve 17 is biased, for example by the biasing means 17B, to the normal second flow path communication state, and the first flow path 12 and the second flow path 13 communicate, and the first cylinder chamber M4 and the second cylinder chamber M5 communicate.

[0034] As a result, in the fluid pressure cylinder M, the high-pressure fluid supplied to the first cylinder chamber M4 flows through the first flow path 12 and the second flow path 13 and is supplied to the low-pressure second cylinder chamber M5.

[0035] Next, when the fluid pressure in the second flow path 13 exceeds a predetermined value, for example, the set pressure at which the regulator 20 begins supplying fluid to the side of the first flow path switching valve 16, fluid is supplied to the side of the second control flow path 19 to the side of the first flow path switching valve 16 by the regulator 20, as shown in Figure 4, and the fluid pressure on the side of the second control flow path 19 to the first flow path switching valve 16 increases. Consequently, the first flow path switching valve 16 enters a first flow path blockage state, the side of the first switching valve 14 in the first flow path switching valve 16 of the first flow path 12 is closed, and the side of the first cylinder chamber M4 is connected to the exhaust port 16A and opened.

[0036] As a result, in the fluid pressure cylinder M, the fluid remaining in the first cylinder chamber M4 is discharged from the exhaust port 16A via the first passage 12, and the piston M2 is pushed and moved towards the side of the first cylinder chamber M4 where the pressure has decreased. This movement of the piston M2 returns the piston rod M3 to its initial state, where it is most retracted into the cylinder body M1, as shown in Figure 5, for example.

[0037] Subsequently, the fluid pressure cylinder M can be driven by repeating the operations described above.

[0038] As described above, according to this embodiment, for example, when moving the piston M2 to the side of the second cylinder chamber M5, the two switching valves 21 are set to the second switching state for supply source communication, the first switching valve 14 is set to the first switching state for supply source side communication, the first flow path switching valve 16 is set to the first flow path communication state via the first control flow path 18, and the second flow path switching valve 17 is set to the second flow path blocking state, thereby connecting the supply source 11 to the first cylinder chamber M4 and opening the side of the second flow path 13 to the second cylinder chamber M5.

[0039] Furthermore, when moving the piston M2 to the side of the first cylinder chamber M4, the second switching valve 21 is set to the supply source shut-off second switching state, the first switching valve 14 is set to the second flow path communication first switching state, the first control flow path 18 is opened, the second flow path switching valve 17 is set to the normal state of second flow path communication, and the first flow path 12 and the second flow path 13 are connected. In addition, when the fluid pressure in the second flow path 13 exceeds a predetermined value, the regulator 20 supplies fluid to the side of the second control flow path 19 to the first flow path switching valve 16, setting the first flow path switching valve 16 to the first flow path shut-off state and opening the side of the first flow path 12 to the first cylinder chamber M4. Thus, the piston M2 can be returned using only the fluid supplied to the first cylinder chamber M4, and the amount of fluid consumed can be further reduced.

[0040] Furthermore, since the first flow path switching valve 16 and the second flow path switching valve 17 are controlled using fluid supplied from the supply source via the first control flow path 18 or the second control flow path 19, there is no need to individually control them electrically, and the configuration can be simplified.

[0041] Furthermore, by utilizing the fact that the pressure on the supply source 11 side of the first switching valve 14 changes depending on the switching state of the second switching valve 21, the first switching valve 14 can be switched, allowing the entire system to be driven by controlling only the second switching valve 21.

[0042] Although the present invention has been described above with reference to embodiments, the present invention is not limited to the above embodiments and can be modified in various ways. For example, although each component was described in detail in the above embodiments, the specific configuration of each component may differ. In addition, the present invention does not have to include all of the above-mentioned components, and may also include other components. [Explanation of Symbols]

[0043] 10... Fluid pressure cylinder drive device, 11... Supply source, 12... First flow path, 13... Second flow path, 14... First switching valve, 15... Control unit, 16... First flow path switching valve, 16A... Exhaust port, 17... Second flow path switching valve, 17A... Exhaust port, 17B... Biasing means, 18... First control flow path, 19... Second control flow path, 20... Regulator, 21... Second switching valve, 21A... Exhaust port, M... Fluid pressure cylinder, M1... Cylinder body, M2... Piston, M3... Piston rod, M4... First cylinder chamber, M5... Second cylinder chamber

Claims

1. A fluid pressure cylinder drive device that drives a fluid pressure cylinder in which the inside of the cylinder body is divided into a first cylinder chamber and a second cylinder chamber by a piston, A supply source that supplies fluid to the aforementioned fluid pressure cylinder, The supply source is connected to the first cylinder chamber via a first flow path, A second flow path is branched from the first flow path and connects the first flow path to the second cylinder chamber, A first switching valve is disposed at the branching point between the first flow path and the second flow path, and switches between a first supply source side communication switching state in which the supply source side of the first flow path is connected to the first cylinder chamber side and communication between the second flow path and the first flow path is blocked, and a first second flow path communication switching state in which communication between the supply source side of the first flow path and the first cylinder chamber side is blocked and the second flow path is connected to the first cylinder chamber side of the first flow path. A first flow path switching valve is disposed on the first cylinder chamber side of the first flow path and switches between a first flow path communication state that connects the first flow path and a first flow path blocking state that closes the first switching valve side of the first flow path and opens the first cylinder chamber side, A second flow path switching valve is provided in the second flow path and switches between a second flow path communication state, which connects the second flow path, and a second flow path blocking state, which closes the first switching valve side of the second flow path and opens the second cylinder chamber side, and sets the second flow path communication state to the normal state. A first control channel is branched from the first channel on the supply source side of the first switching valve, and controls the first channel switching valve to be in a state of first channel communication, and controls the second channel switching valve to be in a state of second channel blockage, A second control channel is branched from the second flow path on the second cylinder chamber side of the second flow path switching valve and controls the first flow path switching valve to a first flow path blocking state, A regulator is provided in the second control channel, and when the fluid pressure in the second channel is above a predetermined value, it supplies fluid to the first channel switching valve and puts the first channel switching valve into a first channel shut-off state. A second switching valve is disposed on the supply source side of the branching portion of the first control passage in the first flow path, and switches between a supply source communication second switching state that connects to the supply source and a supply source shutdown second switching state that shuts off communication with the supply source and opens the first control passage. A fluid pressure cylinder drive device characterized by having the following features.

2. When moving the piston toward the second cylinder chamber, the second switching valve is set to the second switching state for supply source communication, the first switching valve is set to the first switching state for supply source side communication, the first flow path switching valve is set to the first flow path communication state via the first control flow path, and the second flow path switching valve is set to the second flow path blocking state, thereby connecting the supply source to the first cylinder chamber and opening the second cylinder chamber side of the second flow path. When moving the piston toward the first cylinder chamber, the second switching valve is set to the supply source shut-off second switching state, the first switching valve is set to the second flow path communication first switching state, the first control flow path is opened, and the second flow path switching valve is set to the normal state of second flow path communication, connecting the first flow path and the second flow path. Furthermore, when the fluid pressure in the second flow path exceeds a predetermined value, the regulator supplies fluid to the first flow path switching valve side of the second control flow path, setting the first flow path switching valve to the first flow path shut-off state and opening the first cylinder chamber side of the first flow path. The fluid pressure cylinder drive device according to claim 1, characterized in that it is a fluid pressure cylinder drive device as described in claim 1.

3. The fluid pressure cylinder drive device according to claim 1, characterized in that the first switching valve is configured to switch between a first switching state of communication with the supply source and a first switching state of communication with the second flow path, by utilizing the fact that the pressure on the supply source side of the first switching valve changes depending on the switching state of the second switching valve.

Images