JP7147679B2 - pilot lock valve - Google Patents

Description

The present invention relates to pilot lock valves.

A pilot lock valve (pilot check valve) is known as a lock valve that controls the flow of working fluid such as oil. For example, Patent Literature 1 describes a pilot check valve provided between a helm pump, a cylinder, and a tank. The pilot check valve includes a pilot piston, left and right poppets and a valve housing. A pilot piston is located between the left and right poppets. The valve housing houses the pilot piston and left and right poppets.

The valve housing is formed with a left channel connecting the helm pump and the cylinder and a right channel connecting the tank and the cylinder. Further, left and right partition walls are provided to intersect with the left and right flow paths, respectively, and openings are formed in each partition wall. When the helm pump is not in operation, the left and right poppets close the openings in the left and right bulkheads, respectively. As a result, each flow path is blocked and the cylinder does not move.

During operation of the helm pump, for example, oil flows into the left channel. In this case, the hydraulic pressure moves the left poppet leftward to open the opening in the left bulkhead and moves the pilot piston rightward. Also, the right poppet is pushed by the push rod portion of the pilot piston and moves rightward to open the opening of the right partition wall. As a result, the left and right flow paths are opened, and oil flows from the helm pump into the cylinder and returns from the cylinder to the tank. As a result, the cylinder moves to the right.

JP 2012-77890 A

In the pilot check valve of Patent Document 1, when the opening of the partition wall is opened, the push rod portion of the pilot piston is inserted through the opening. The annular area becomes a substantial flow path. If the cross-sectional area of the flow path is small, the pressure loss increases, so it is desirable to increase the cross-sectional area of the flow path.

However, in order to increase the cross-sectional area of the flow path, it is necessary to increase the diameter of the opening of the partition wall and the diameter of the poppet that opens and closes the opening, which increases the size of the valve housing. As a result, the cost of the pilot check valve increases and the degree of freedom in arranging the pilot check valve decreases.

SUMMARY OF THE INVENTION An object of the present invention is to provide a pilot lock valve with reduced pressure loss without increasing its size.

A mode according to one aspect of the present invention is a pilot lock valve provided in a flow path between a fluid pressure actuator and a fluid reservoir, the first valve having a first inner peripheral surface extending in a predetermined axial direction. a body portion having a housing portion, a first port connectable to the fluid pressure actuator, and a second port connectable to the fluid reservoir portion; and a first outer peripheral surface extending in the axial direction, The first inner periphery of the first valve housing portion having a first poppet reciprocally movable in the axial direction within the first valve housing portion and first and second communication holes. a first sleeve disposed between a surface and the first outer peripheral surface of the first poppet; and a drive member receiving a pilot pressure to drive the first poppet. The port communicates with the first valve accommodating portion through a first communication opening on the first inner peripheral surface, and the second port communicates with the valve housing portion through a second communication opening on the first inner peripheral surface. In communication with the first valve housing, the first poppet separates the first port and the second port from each other at the first outer peripheral surface when not driven by the drive member. and communicates the first port and the second port through the first communication hole and the second communication hole of the first sleeve when driven by the drive member. The first sleeve moves so as to form one main flow path, and the first sleeve moves in the first communication hole of the first main flow path according to the pressure of the fluid supplied from the fluid pressure actuator. The present invention relates to a pilot lock valve provided movably in the axial direction such that at least one of an opening area of one and a second opening area of the second communication hole is changed.

ADVANTAGE OF THE INVENTION According to this invention, a pressure loss can be reduced, without enlarging a pilot lock valve.

1 is a diagram showing a configuration of a working machine provided with a pilot lock valve according to an embodiment of the invention; FIG. FIG. 2 is a cross-sectional view showing the configuration of the pilot lock valve of FIG. 1; 3 is an enlarged partial cross-sectional view of the pilot lock valve of FIG. 2; FIG. It is a figure which shows the connection relationship of a pilot lock valve. It is a figure which shows the connection relationship of a pilot lock valve. It is a figure for demonstrating operation|movement of a pilot lock valve. It is a figure for demonstrating operation|movement of a pilot lock valve. FIG. 5 is an enlarged partial cross-sectional view of the pilot lock valve when the ports are open; FIG. 5 is an enlarged partial cross-sectional view of the pilot lock valve when the ports are open; FIG. 4 is a cross-sectional view showing the configuration of a pilot lock valve according to a reference example; 11 is a diagram for explaining the operation of the pilot lock valve of FIG. 10; FIG. FIG. 12 is a cross-sectional view of the pilot lock valve of FIG. 11 taken along line AA; FIG. 4 is a diagram showing measurement results of pressure loss in Examples and Comparative Examples.

(1) Work Machine A pilot lock valve according to one embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing the construction of a working machine including a pilot lock valve according to one embodiment of the present invention. As shown in FIG. 1 , work machine 200 includes pilot lock valve 100 , fluid reservoir 110 , fluid supply 120 and fluid pressure actuator 130 .

In the present embodiment, work machine 200 is a forklift, and further includes fork (claw) 210 , seat 220 and operator 230 . Note that the embodiment is not limited to this, and the work machine 200 may be a work machine other than a forklift.

The fork 210 raises and lowers a load to be worked. A user of work machine 200 (hereinafter referred to as a worker) sits on seat 220 . A seat switch 221 is provided below the seat 220 . When the worker is seated on the seat 220, the seat switch 221 is turned on. On the other hand, when the operator leaves the seat 220, the seat switch 221 is turned off.

The operator 230 is, for example, a shift lever for operating the fork 210, and is operated by the operator. The manipulator 230 is in one of the neutral state, the first operating state, and the second operating state, and is in the neutral state when not operated by the operator (when the operator releases the operator's hand from the manipulator 230). Become.

Pilot lock valve 100 is provided in a flow path between fluid storage portion 110 , fluid supply portion 120 and fluid pressure actuator 130 . The details of the configuration of the pilot lock valve 100 will be described later. In this example, a directional control valve 231 is interposed between the pilot lock valve 100 and the fluid storage section 110 and the fluid supply section 120 . The directional control valve 231 switches the connection relationship between the pilot lock valve 100 and the fluid storage section 110 and the fluid supply section 120 in accordance with the state of the operator 230 .

The fluid storage unit 110 is, for example, a tank, and stores working fluid such as oil (hereinafter simply referred to as fluid). The fluid supply unit 120 is, for example, a pump, and pressure-feeds the fluid stored in the fluid storage unit 110 toward the direction control valve 231 . A return pipe 121 is connected to the fluid supply portion 120 to return the fluid pressure-fed from the fluid storage portion 110 to the fluid storage portion 110 . An electromagnetic unload valve 222 is inserted in the return pipe 121 . The electromagnetic unload valve 222 is closed when the seat switch 221 is on, and is open when the seat switch 221 is off.

The fluid pressure actuator 130 is, for example, a fluid pressure cylinder (fork shifter) that shifts the fork 210 left and right, and is operated by fluid pressure. In this example, the fluid pressure actuator 130, which is a fluid pressure cylinder, includes a piston 131 (see FIG. 4, which will be described later). Actuation of the hydraulic actuator 130 means movement of the piston 131 in a predetermined direction or in the opposite direction.

(2) Structure of Pilot Lock Valve FIG. 2 is a cross-sectional view showing the structure of the pilot lock valve 100 of FIG. As shown in FIG. 2 , the pilot lock valve 100 includes a cylindrical body portion 10 extending in one direction and a drive member 20 . The direction in which the main body 10 extends is called the axial direction. A hollow portion is formed in the body portion 10 so as to extend in the axial direction. A portion near the center of the hollow portion in the axial direction is called a central housing portion 11 . Each of the two ends of the cavity in the axial direction is called a valve housing portion 12 . That is, the central housing portion 11 is positioned between the pair of valve housing portions 12 in the axial direction.

A port 1 penetrating from a portion of the outer surface to an inner peripheral surface 13 of the valve housing portion 12 is formed at each of both end portions of the body portion 10, and the valve housing portion 12 extends from another portion of the outer surface. A port 2 penetrating to the inner peripheral surface 13 is formed. Therefore, the one port 1 communicates with the one valve accommodating portion 12 at the communication opening 14 of the one inner peripheral surface 13 . One port 2 communicates with one valve accommodating portion 12 through a communicating opening 15 in one inner peripheral surface 13 . The other port 1 communicates with the other valve accommodating portion 12 at the communication opening 14 of the other inner peripheral surface 13 . The other port 2 communicates with the other valve accommodating portion 12 at the communication opening 15 of the other inner peripheral surface 13 . In addition, the shape of the inner peripheral surface 13 may be circular, or may be another shape such as a polygon.

The driving member 20 includes, for example, a piston driven by receiving pilot pressure (fluid pressure), and is composed of a piston body 21 and a pair of push rod portions 22 . The pair of push rod portions 22 protrude and extend from both ends of the piston body 21 in the axial direction. A piston body 21 is accommodated in the central accommodating portion 11 so as to be reciprocally movable in the axial direction. The piston body 21 blocks movement of the working fluid between the pair of valve housing portions 12 .

Each valve housing portion 12 is provided with a valve body 30, a plug 40, a sleeve 50, a poppet 60, and spring members 70,80. The configuration of one valve accommodating portion 12 will be described below. The configuration of the other valve housing portion 12 is the same as the configuration of the one valve housing portion 12, so the description thereof is omitted.

FIG. 3 is an enlarged partial cross-sectional view of the pilot lock valve 100 of FIG. As shown in FIG. 3 , the valve body 30 includes a cylindrical side portion 31 and a bottom portion 32 . The bottom portion 32 closes one end of the side portion 31 . The valve body 30 is inserted into the valve accommodating portion 12 with the bottom portion 32 facing (inwardly) the piston body 21 of the drive member 20 .

Communicating holes 33 and 34 respectively connected to the ports 1 and 2 are formed in the side portion 31 . The bottom surface portion 32 is formed with an opening 35 that holds one push rod portion 22 of the driving member 20 so as to be axially movable. The other end of the side surface portion 31 of the valve body 30 is open while protruding from the body portion 10 in the axial direction. A plug 40 is filled in the opening 36 at the other end of the side portion 31 . Thereby, the opening 36 of the side portion 31 is closed.

The sleeve 50 includes a cylindrical side portion 51 and a bottom portion 52, and is accommodated inside the valve body 30 so as to be axially movable and with the bottom portion 52 facing inward. Communication holes 53 and 54 corresponding to the communication hole 33 are formed in the side surface portion 51, and communication holes 55 and 56 corresponding to the communication hole 34 are formed. Depending on the position of the sleeve 50 in the axial direction, the communicating hole 53 or communicating hole 54 overlaps the communicating hole 33 (port 1), and the communicating hole 55 or communicating hole 56 overlaps the communicating hole 34 (port 2). A communication hole 57 is formed in the bottom surface portion 52 . The shape of each of the communication holes 53 to 57 is circular, for example, but may be other shapes.

The poppet 60 has a rod shape extending in the axial direction and is arranged inside the sleeve 50 so as to be axially movable. Therefore, the sleeve 50 is positioned between the inner peripheral surface 13 of the valve housing portion 12 and the outer peripheral surface 61 of the poppet 60 . The cross-sectional shape of the outer peripheral surface 61 may be circular or other shapes such as polygonal. Depending on the position of the poppet 60 in the axial direction, the poppet 60 blocks at least part of the communicating holes 53 to 57 of the sleeve 50 . The area of each of the communication holes 53 to 56 closed by the outer peripheral surface 61 of the poppet 60 changes depending on the position of the poppet 60 in the axial direction.

The valve housing portion 12 is separated into an interior space 16 and an interior space 17 by a sleeve 50 and a poppet 60 . Further, a fluid supply passage 18 communicating from the port 1 to the internal space 16 is formed in the body portion 10 . Port 2 communicates with fluid supply passage 18 when poppet 60 is driven toward opening 36 (outward).

The spring member 70 is arranged between the bottom surface portion 32 of the valve body 30 and the bottom surface portion 52 of the sleeve 50 in the internal space 17 while surrounding the push rod portion 22 on one side of the drive member 20 . The spring member 70 supports the sleeve 50 on the bottom portion 32 of the valve body 30 and urges it outward. Spring member 80 is arranged between plug 40 and one end surface (rear end surface 63 ) of poppet 60 in internal space 16 . The spring member supports the poppet 60 on the plug 40 and biases it inwardly.

When the manipulator 230 is in the neutral state, the spring members 70 and 80 have the communication holes 53 to 56 of the sleeve 50 closed by the outer peripheral surface 61 of the poppet 60, and the communication hole 57 of the sleeve 50 is connected to the other end surface of the poppet 60 ( It is configured to be occluded by the distal end surface 62). That is, poppet 60 separates port 1 and port 2 from each other at outer peripheral surface 61 when not driven by drive member 20 .

On the other hand, poppet 60 is driven by drive member 20 when manipulator 230 is in the first or second operating state. In this case, the poppet 60 moves so that the communication holes 53 and 54 are at least partially opened and the communication holes 55 to 57 are at least partially opened. As a result, a main flow path that communicates between the ports 1 and 2 is formed, and fluid can move between the ports 1 and 2 through the valve housing portion 12 . The operation of the pilot lock valve 100 will be described below.

(3) Operation of Pilot Lock Valve In FIGS. 4 to 7 below, the one and the other valve accommodating portions 12 are referred to as valve accommodating portions 12a and 12b, respectively. Further, the constituent elements corresponding to the valve accommodating portion 12a will be described by adding "a" to the reference numerals of the constituent elements. Components corresponding to the valve housing portion 12b will be described by adding "b" to the reference numerals of the components. For example, the ports 1 and 2 corresponding to the valve housing portion 12a are respectively described as ports 1a and 2a, and the ports 1 and 2 corresponding to the valve housing portion 12b are respectively described as ports 1b and 2b.

4 and 5 are diagrams showing connection relationships of the pilot lock valve 100. FIG. As shown in FIGS. 4 and 5, ports 1a and 1b of pilot lock valve 100 are connected to one end and the other end of fluid pressure actuator 130, respectively. Ports 2 a and 2 b of pilot lock valve 100 are connected to directional control valve 231 . The direction control valve 231 is connected to the fluid reservoir 110 and the fluid supply part 120 , and switches the connection relationship between the ports 2 a and 2 b and the fluid reservoir 110 and the fluid supply part 120 according to the state of the operator 230 .

Specifically, when the operator 230 is in the first operating state, the directional control valve 231 connects the port 2 a and the fluid reservoir 110 and connects the port 2 b and the fluid supply 120 . When the operator 230 is in the second operating state, the directional control valve 231 connects the port 2a and the fluid supply section 120 and connects the port 2b and the fluid storage section 110 . When the operator 230 is in the neutral state, the directional control valve 231 cuts off the connection between the ports 2a and 2b and the fluid storage section 110 and the fluid supply section 120. FIG.

In the example of FIG. 4, the manipulator 230 is in the neutral state. In this case, since the communication holes 53a to 57a of the sleeve 50a are closed by the poppet 60a, fluid does not move between the ports 1a and 2a. Further, since the communication holes 53b to 57b of the sleeve 50b are blocked by the poppet 60b, fluid does not move between the ports 1b and 2b. Therefore, regardless of the state of electromagnetic unload valve 222, fluid pressure actuator 130 does not operate. In the example of FIG. 4, since the operator is seated on the seat 220 of FIG. 1, the electromagnetic unload valve 222 is closed.

In the example of FIG. 5, the worker is out of the seat (the seat switch 221 is off). In this case, since the electromagnetic unload valve 222 inserted in the return pipe 121 from the fluid supply portion 120 to the fluid storage portion 110 is in an open state, most of the fluid pressure-fed by the fluid supply portion 120 is transferred to the return pipe. 121 back to fluid reservoir 110 . Therefore, little fluid is supplied to the directional control valve 231 . This state is called an unload state. In the unloaded state, the pressure of the fluid supplied to the directional control valve 231 is less than the cracking pressure of the poppets 60a, 60b.

Here, when the operator 230 is switched from the neutral state to a different operating state (the first operating state in the example of FIG. 5), part of the fluid flows from the port 1a into the internal space 16a through the fluid supply passage 18a. In this case, the pressure of the fluid causes the sleeve 50a to move inward while contracting the spring member 70a against the outward biasing force of the spring member 70a. Also, the pressure of the fluid and the biasing force of the spring member 80a cause the poppet 60a to move inward and come into contact with the end surface of the push rod portion 22a of the drive member 20. As shown in FIG. Even in this case, since the communication holes 53a to 57a of the sleeve 50a remain closed by the poppet 60a, fluid does not move between the ports 1a and 2a.

On the other hand, the driving member 20 is pushed by the poppet 60a to move closer to the poppet 60b, but does not move so much that the tip surface of the push rod portion 22b contacts the poppet 60b. Therefore, the communication holes 53b to 57b of the sleeve 50b are kept closed by the poppet 60b, and fluid does not move between the ports 1b and 2b. Thus, when the operator leaves the seat, the operation of the fluid pressure actuator 130 is prevented even when the operator 230 is switched to the first or second operation state. Thereby, the reliability of work machine 200 can be improved.

6 and 7 are diagrams for explaining the operation of pilot lock valve 100. FIG. In the example of FIGS. 6 and 7, the operator 230 is switched to the first operating state while the operator is seated on the seat 220 of FIG. 1 (the electromagnetic unload valve 222 is closed). In this case, as in the example of FIG. 5, in the valve accommodating portion 12a, as shown in FIG. 60a begins to move inward.

On the other hand, the valve housing portion 12b is supplied with fluid by the fluid supply portion 120 through the port 2b. In this case, the driving member 20 moves toward the poppet 60a due to the pressure of the fluid, and the tip surface of the push rod portion 22a comes into contact with the poppet 60a. At this time, the space between the piston main body 21 and the valve body 30 a in the central housing portion 11 becomes the damper space 19 .

Specifically, as the drive member 20 approaches the valve body 30a, the pressure in the damper space 19 increases, and the moving speed of the drive member 20 decreases. Therefore, the push rod portion 22a does not come into contact with the poppet 60a with a strong momentum. This prevents the push rod portion 22a or the poppet 60a from being damaged. In addition, it is possible to prevent the impact noise from being generated when the push rod portion 22a comes into contact with the poppet 60a. Thereafter, as shown in FIG. 7, the driving member 20 pushes the poppet 60a outward against the inward biasing force by the push rod portion 22a.

The poppet 60a is pushed by the push rod portion 22 to move outward. Here, since the movement directions of the sleeve 50a and the poppet 60a are opposite, the poppet 60a is separated from the sleeve 50a, and the communication holes 53a to 57a of the sleeve 50a are opened. The communication holes 33a, 34a of the valve body 30a overlap the communication holes 53a, 56a of the sleeve 50a, respectively. As a result, the port 1a and the port 2a are opened in the valve accommodating portion 12a through the communicating holes 33a, 53a, 56a, and 34a.

In the valve accommodating portion 12b, the pressure of the fluid supplied from the port 2b causes the poppet 60b to move outward while compressing the spring member 80b. In this case, the communication holes 54b, 56b, 57b of the sleeve 50b are opened. Also, the communicating hole 33b of the valve body 30b overlaps with the communicating hole 54b of the sleeve 50b. As a result, the port 2b and the port 1b are opened through the communication holes 34b, 57b, 54b, and 33b inside the valve accommodating portion 12b.

According to the operation of the pilot lock valve 100 described above, the main flow path 101 is formed for the fluid to move from the port 1a connected to one end of the fluid pressure actuator 130 to the port 2a connected to the fluid reservoir 110. . This establishes communication between the port 1a and the port 2a. Also, a main flow path 102 is formed for fluid to move from the port 2b connected to the fluid supply part 120 to the port 1b connected to the other end of the fluid pressure actuator 130 . This establishes communication between the port 2b and the port 1b. As a result, the fluid pressure actuator 130 operates such that the piston 131 moves in one direction.

Similarly, when the operator 230 is switched to the second operating state, the fluid moves from the port 1b connected to the other end of the fluid pressure actuator 130 to the port 2b connected to the fluid reservoir 110. A main flow path 101 is formed for this purpose. This establishes communication between the port 1b and the port 2b. Also, a main flow path 102 is formed through which the fluid moves from the port 2a connected to the fluid supply part 120 to the port 1a connected to one end of the fluid pressure actuator 130 . This establishes communication between the port 2a and the port 1a. As a result, the fluid pressure actuator 130 operates so that the piston 131 moves in the other direction.

8 and 9 are enlarged partial cross-sectional views of pilot lock valve 100 when ports 1 and 2 are open. In the example of FIG. 8, the flow rate (pressure) of the fluid supplied to port 1 is large. In this case, since the difference between the pressure in the internal space 16 and the pressure in the internal space 17 is large, the amount of movement of the sleeve 50 is large. At this movement amount, the sleeve 50 has a large opening area (X section in FIG. 8) at the communication hole 53 of the main flow path 101 and a large opening area (Y section in FIG. 8) at the communication hole 56 of the main flow path 101. configured to be Thereby, pressure loss can be reduced.

On the other hand, in the example of FIG. 9, the flow rate of the fluid supplied to port 1 is small. In this case, since the difference between the pressure in the internal space 16 and the pressure in the internal space 17 is small, the amount of movement of the sleeve 50 is small. At this amount of movement, the opening area of the communication hole 53 of the main flow path 101 (X section in FIG. 9) is small, and the opening area of the communication hole 56 of the main flow path 101 is small (Y section in FIG. 9). However, since the flow rate of fluid is small, excessive pressure loss does not occur.

Thus, the sleeve 50 moves in the axial direction so that the opening area of the communication hole 53 and the opening area of the communication hole 56 of the main flow path 101 change according to the pressure of the fluid supplied from the hydraulic actuator 130. . The sleeve 50 may move in the axial direction so that only one of the opening area of the communication hole 53 and the opening area of the communication hole 56 of the main flow path 101 changes according to the pressure of the fluid. .

In this example, when the flow rate of the fluid is equal to or higher than a predetermined value, the amount of movement of the sleeve 50 is maximized, and the opening areas of the communication holes 53 and 56 of the main flow path are at their maximum constant values. This fluid flow rate region is called a fixed throttle region. When the flow rate of the fluid is smaller than a predetermined value, the opening area of the communication hole 53 and the opening area of the communication hole 56 of the main flow path change according to the amount of movement of the sleeve 50 . This fluid flow rate region is called a variable throttle region.

(4) Example and Comparative Example FIG. 10 is a cross-sectional view showing the configuration of a pilot lock valve according to a reference example. As shown in FIG. 10, pilot lock valve 300 includes body portion 310, piston 320, and left and right poppets 330, 340. As shown in FIG. Body portion 310 has a tubular shape extending in the left-right direction and accommodates piston 320 and poppets 330 and 340 . Both ends of the body portion 310 in the left-right direction are closed.

Left and right partition walls 350 and 360 are provided in parallel and apart from each other inside the body portion 310 . As a result, the space inside the body portion 310 is partitioned into three. Inside the body portion 310 , the space between the partitions 350 and 360 is called a central space 311 , the space to the left of the partition 350 is called a space 312 , and the space to the right of the partition 360 is called a right space 313 . Openings 351 and 361 are formed in the partition walls 350 and 360, respectively.

The piston 320 includes a piston body 321 and left and right push rods 322 and 323 . A piston body 321 of the piston 320 is arranged in the central space 311 so as to be movable in the left-right direction. The push rod portions 322 and 323 protrude from the left and right end faces of the piston body 321, respectively. Poppet 330 is disposed in left space 312 and is biased to close opening 351 of partition 350 from the left. The poppet 340 is placed in the right space 313 and is biased to close the opening 361 of the partition wall 360 from the right side.

Ports 314 to 317 are formed on the side surface of the body portion 310 . The port 314 penetrates from the outside to the area between the piston body 321 and the partition 350 in the central space 311 . The port 315 penetrates from the outside to the area between the piston body 321 and the diaphragm 360 in the central space 311 . A port 316 penetrates from the outside to the left space 312 . A port 317 penetrates from the outside to the right space 313 . Ports 314 and 315 are connected to fluid supply 120 and fluid reservoir 110, respectively. Ports 316 and 317 are connected to one end and the other end of hydraulic actuator 130, respectively.

FIG. 11 is a diagram for explaining the operation of pilot lock valve 300 of FIG. FIG. 12 is a cross-sectional view of the pilot lock valve 300 of FIG. 11 taken along line AA. As indicated by the thick arrows in FIG. 11, fluid flows through port 314 during operation of fluid supply 120 . In this case, the pressure of the fluid causes the poppet 330 to move leftward to open the opening 351 of the partition wall 350 and the piston 320 to move rightward.

Also, the poppet 340 is pushed by the push rod portion 323 and moves rightward to open the opening 361 of the partition wall 360 . As a result, the flow path between the ports 314 and 316 and the flow path between the ports 315 and 317 are opened, and the fluid flows from the fluid supply portion 120 to the fluid pressure actuator 130 and from the fluid pressure actuator 130 to the fluid storage portion 110. return. As a result, the fluid pressure actuator 130 operates.

Here, as shown in FIG. 12, when the opening 361 of the partition wall 360 is opened, the push rod portion 323 is inserted through the opening 361, so that the annular gap between the outer peripheral portion of the push rod portion 323 and the inner peripheral portion of the opening 361 is displaced. becomes the substantial flow path 318 . Therefore, when the cross-sectional area of flow path 318 is small, the pressure loss increases.

As an example, the pressure loss was measured using the pilot lock valve 100 of FIG. Further, as a comparative example, pressure loss was measured using a pilot lock valve 300 having a diameter similar to that of the pilot lock valve 100 according to the embodiment. FIG. 13 is a diagram showing measurement results of pressure loss in Examples and Comparative Examples. The horizontal axis of FIG. 13 indicates the flow rate of the fluid, and the vertical axis indicates the pressure loss. A solid line indicates the measurement results in the example, and a dotted line indicates the measurement results in the comparative example.

As shown in FIG. 13, it was measured that the pressure loss in the example was larger than the pressure loss in the comparative example in the variable throttle region where the flow rate of the fluid was small. However, practically, the pilot lock valve 100 is rarely used in the variable throttle region. Also, as described above, in the variable throttle region, the flow rate of the fluid is small, so excessive pressure loss does not occur.

On the other hand, it was measured that in the fixed throttle region, the larger the flow rate of the fluid, the smaller the difference between the pressure loss in the example and the pressure loss in the comparative example. Moreover, as indicated by the dashed line, it was measured that the pressure loss in the example was smaller than the pressure loss in the comparative example in the range of the flow rate of the fluid that was practically used. Accordingly, it was confirmed that the pilot lock valve 100 according to the embodiment reduces the pressure loss without increasing the size of the main body 10 .

(5) Effect In the pilot lock valve 100 according to the present embodiment, the sleeve 50 is arranged between the inner peripheral surface 13 of the valve housing portion 12 and the outer peripheral surface 61 of the poppet 60 in the main body portion 10 . The port 1 of the body portion 10 can be connected to a fluid pressure actuator 130 and communicates with the valve accommodating portion 12 through the communication opening 14 of the inner peripheral surface 13 . The port 2 of the body portion 10 can be selectively connected to either one of the fluid storage portion 110 and the fluid supply portion 120 , and communicates with the valve housing portion 12 through the communication opening 15 of the inner peripheral surface 13 .

When drive member 20 does not drive poppet 60 , port 1 and port 2 are separated from each other by outer peripheral surface 61 of poppet 60 . On the other hand, when the driving member 20 receives the pilot pressure and drives the poppet 60, the main flow path 101 communicates the ports 1 and 2 through one of the communication holes 53 and 54 and one of the communication holes 55 to 57 of the sleeve 50. The poppet 60 moves axially within the valve housing portion 12 so that a is formed. Here, by moving the sleeve 50 in the axial direction according to the pressure of the fluid supplied from the fluid pressure actuator 130, the opening area of the communication holes 53 and 54 of the main flow path 101 and the opening area of the communication holes 55 to 57 at least one of changes.

According to this configuration, any one of the communication holes 55 to 57 of the main flow passage 101 can be enlarged without increasing the size of the inner peripheral surface 13 of the valve accommodating portion 12 in the radial direction. Moreover, since the opening areas of the communication holes 55 to 57 of the main flow path 101 change according to the flow rate of the fluid, excessive pressure loss does not occur in the main flow path 101 . In particular, since the moving direction of the poppet 60 and the moving direction of the sleeve 50 are opposite to each other, the opening area can be increased even when the pressure of the fluid supplied from the fluid pressure actuator 130 is relatively small. As a result, pressure loss can be reduced without increasing the size of the pilot lock valve 100 .

(6) Correspondence between Each Component of the Claim and Each Part of the Embodiment An example of correspondence between each component of the claim and each part of the embodiment will be described. In the above embodiment, the valve housing portions 12a and 12b are examples of the first and second valve housing portions, respectively, and the internal spaces 16 and 17 are examples of the first and second internal spaces, respectively.

The inner peripheral surface 13 of the valve accommodating portion 12a is an example of the first inner peripheral surface, the ports 1 and 2 are examples of the first and second ports, respectively, and the outer peripheral surface 61 is an example of the first outer peripheral surface. and poppet 60 is an example of a first poppet. Any one of the communication holes 53 and 54 in the valve accommodating portion 12a is an example of a first communication hole, any one of the communication holes 55 to 57 is an example of a second communication hole, and the sleeve 50 is a first sleeve. , and the communication openings 14 and 15 are examples of the first and second communication openings, respectively.

The inner peripheral surface 13 of the valve accommodating portion 12b is an example of the second inner peripheral surface, the ports 1 and 2 are examples of the third and fourth ports, respectively, and the outer peripheral surface 61 is an example of the second outer peripheral surface. and poppet 60 is an example of a second poppet. Any one of the communication holes 53 and 54 in the valve accommodating portion 12b is an example of a third communication hole, any one of the communication holes 55 to 57 is an example of a fourth communication hole, and the sleeve 50 is a second sleeve. , and the communication openings 14 and 15 are examples of the third and fourth communication openings, respectively.

When the operator 230 is in the first operating state, the main flow path 101 in the valve housing portion 12a is an example of the first main flow path. When the operator 230 is in the second operating state, the main flow path 102 in the valve housing portion 12a is an example of the second main flow path, and the main flow path 101 in the valve housing portion 12b is an example of the third main flow path. .

(7) Aspect (Section 1) A pilot lock valve according to one aspect is
A pilot lock valve provided in a flow path between a fluid pressure actuator and a fluid reservoir,
A main body having a first valve housing portion having a first inner peripheral surface extending in a predetermined axial direction, a first port connectable to the fluid pressure actuator, and a second port connectable to the fluid reservoir portion. Department and
a first poppet having a first outer peripheral surface extending in the axial direction and reciprocally movable in the axial direction within the first valve housing;
A first valve having first and second communication holes and disposed between the first inner peripheral surface of the first valve housing portion and the first outer peripheral surface of the first poppet a sleeve;
a driving member that receives pilot pressure to drive the first poppet;
the first port communicates with the first valve accommodating portion at a first communication opening of the first inner peripheral surface;
the second port communicates with the first valve accommodating portion at a second communication opening of the first inner peripheral surface;
The first poppet is arranged to separate the first port and the second port from each other at the first outer peripheral surface when not driven by the drive member, and is driven by the drive member. so that a first main flow path is formed that communicates the first port and the second port through the first communication hole and the second communication hole of the first sleeve when the move and
The first sleeve has a first opening area at the first communication hole of the first main flow path and a first opening area at the second communication hole in accordance with the pressure of the fluid supplied from the fluid pressure actuator. It may be provided movably in the axial direction so that at least one of the two opening areas is changed.

In this pilot lock valve, the first sleeve is arranged between the first inner peripheral surface of the first valve accommodating portion and the first outer peripheral surface of the first poppet in the body portion. A first port of the body portion is connectable to the fluid pressure actuator and communicates with the first valve housing portion at a first communication opening of the first inner peripheral surface. A second port of the body is connectable to the fluid reservoir and communicates with the first valve housing at a second communication opening in the first inner peripheral surface.

When the drive member does not drive the first poppet, the first port and the second port are separated from each other by the first outer peripheral surface of the first poppet. On the other hand, when the driving member receives the pilot pressure and drives the first poppet, the first port and the second port are communicated through the first communicating hole and the second communicating hole of the first sleeve. The first poppet moves axially within the first valve housing such that one main flow path is formed. Here, by moving the first sleeve in the axial direction according to the pressure of the fluid supplied from the fluid pressure actuator, the first opening area in the first communication hole of the first main flow path and the second At least one of the second opening areas of the communicating hole of is changed.

According to this configuration, it is possible to increase the size of the first or second communication hole of the first main flow path without increasing the dimension of the first inner peripheral surface of the first valve accommodating portion in the radial direction. be possible. In addition, since the first opening area of the first communication hole or the second opening area of the second communication hole changes according to the flow rate of the fluid, excessive pressure loss occurs in the first main flow path. never. As a result, the pressure loss can be reduced without increasing the size of the pilot lock valve.

(Section 2) In the pilot lock valve according to Section 1,
The first sleeve may be configured such that at least one of the first opening area and the second opening area increases as the pressure of the fluid supplied from the fluid pressure actuator increases.

In this case, the larger the pressure of the fluid supplied from the fluid pressure actuator, the larger the first opening area or the second opening area. Thereby, when the flow rate of the fluid is large, the pressure loss can be reduced more efficiently.

(Section 3) In the pilot lock valve according to Section 1 or 2,
the first poppet is biased in a first direction in the axial direction;
the first sleeve is biased in a second direction opposite the first direction;
the driving member receiving the pilot pressure to move the first poppet in the second direction against the biasing force in the first direction;
The body portion directs a portion of the fluid supplied to the first port to the first valve accommodating portion so that the first sleeve moves against the biasing force in the second direction. It may have a fluid supply passage for supplying.

In this case, since the moving direction of the first poppet and the moving direction of the first sleeve are opposite, even if the pressure of the fluid supplied from the hydraulic actuator is relatively small, the first opening area and the second It is possible to increase at least one of the opening areas of the Thereby, pressure loss can be further reduced.

(Section 4) In the pilot lock valve described in Section 3,
the first valve housing is separated into first and second internal spaces by the first poppet and the first sleeve;
the fluid supply passage communicates with the first interior space and the second port communicates with the second interior space when the first poppet is driven in the second direction;
The first sleeve moves such that the at least one of the first and second opening areas increases as the difference between the pressure in the first internal space and the pressure in the second internal space increases. may

In this case, the first opening area or the second opening area can be easily changed according to the pressure of the fluid supplied from the fluid pressure actuator.

(Section 5) In the pilot lock valve according to any one of Sections 1 to 4,
the driving member includes a piston movably provided in the axial direction by receiving the pilot pressure;
A damper space may be formed between the first poppet and the piston.

In this case, the momentum of the piston when driving the first poppet is reduced by the damper space. This prevents damage to the piston or the first poppet. Impulsive noise is prevented from occurring when driving the first poppet.

(Section 6) In the pilot lock valve according to any one of Sections 1 to 5,
the second port is selectively connectable to one of the fluid reservoir and the fluid supply;
The first poppet receives the pressure of the fluid supplied to the second port by the fluid supply section, and connects the second port and the first port to the second port of the first sleeve. may be moved so as to form a second main flow path that communicates through the communicating hole and the first communicating hole.

In this case, the fluid is supplied from the fluid supply section connected to the second port through the second main flow path to the fluid pressure actuator connected to the first port. Thereby, the fluid pressure actuator can be operated.

(Section 7) In the pilot lock valve according to Section 6,
The body portion includes a second valve housing portion having a second inner circumferential surface extending in the axial direction, a third port connectable to the fluid pressure actuator, and one of the fluid storage portion and the fluid supply portion. further comprising a fourth port selectively connectable to
a second poppet having a second outer peripheral surface extending in the axial direction and reciprocally movable in the axial direction within the second valve housing;
A second valve having third and fourth communication holes and disposed between the second inner peripheral surface of the second valve accommodating portion and the second outer peripheral surface of the second poppet. It further comprises a sleeve and
The driving member uses the pressure of the fluid from the fluid supply section as the pilot pressure when the fluid storage section is connected to the second port and the fluid supply section is connected to the fourth port. receiving and driving the first poppet to receive fluid from the fluid supply when the fluid supply is connected to the second port and the fluid reservoir is connected to the fourth port; receiving pressure as the pilot pressure to drive the second poppet, wherein the third port communicates with the second valve accommodating portion through a third communicating opening of the second inner peripheral surface;
the fourth port communicates with the second valve accommodating portion at a fourth communication opening of the second inner peripheral surface;
The second poppet is arranged to separate the third port and the fourth port from each other at the second outer peripheral surface when not driven by the drive member, and is driven by the drive member. so that a third main flow path is formed that communicates the third port and the fourth port through the third communicating hole and the fourth communicating hole of the second sleeve when the move and
The second sleeve has a third opening area in the third communication hole of the third main flow path and a third opening area in the fourth communication hole in accordance with the pressure of the fluid supplied from the fluid pressure actuator. 4 may be provided movably in the axial direction so that at least one of the opening areas is changed.

In this case, fluid pressure from a fluid supply selectively connected to the second or fourth port is applied to the drive member as pilot pressure. Thereby, the first or second poppet can be selectively driven to selectively form the first to third main flow paths.

DESCRIPTION OF SYMBOLS 1, 2, 314-317... Port 10, 310... Main-body part 11... Central accommodating part 12... Valve accommodating part 13... Inner peripheral surface 14, 15... Communication opening 16, 17... Internal space, DESCRIPTION OF SYMBOLS 18... Fluid supply passage 19... Damper space 20... Driving member 21, 321... Piston main body 22, 322, 323... Push rod part 30... Valve body 31, 51... Side part, 32, 52... Bottom part , 33, 34, 53 to 57... communication hole 35, 36, 351, 361... opening 40... plug 50... sleeve 60, 330, 340... poppet 61... outer peripheral surface 62... tip end surface 63... Rear end face 70, 80 Spring member 100, 300 Pilot lock valve 101, 102 Main passage 110 Fluid reservoir 120 Fluid supply 121 Return pipe 130 Fluid pressure actuator 131, DESCRIPTION OF SYMBOLS 320... Piston, 200... Working machine, 210... Fork, 220... Seat, 221... Seat switch, 222... Electromagnetic unloading valve, 230... Operator, 231... Directional control valve, 318... Flow path, 350, 360... Partition wall

Claims (7)

A pilot lock valve provided in a flow path between a fluid pressure actuator and a fluid reservoir,
A main body having a first valve housing portion having a first inner peripheral surface extending in a predetermined axial direction, a first port connectable to the fluid pressure actuator, and a second port connectable to the fluid reservoir portion. Department and
a first poppet having a first outer peripheral surface extending in the axial direction and reciprocally movable in the axial direction within the first valve housing;
A first valve having first and second communication holes and disposed between the first inner peripheral surface of the first valve housing portion and the first outer peripheral surface of the first poppet a sleeve;
a driving member that receives pilot pressure to drive the first poppet;
the first port communicates with the first valve accommodating portion at a first communication opening of the first inner peripheral surface;
the second port communicates with the first valve accommodating portion at a second communication opening of the first inner peripheral surface;
The first poppet is arranged to separate the first port and the second port from each other at the first outer peripheral surface when not driven by the drive member, and is driven by the drive member. so that a first main flow path is formed that communicates the first port and the second port through the first communication hole and the second communication hole of the first sleeve when the move and
The first sleeve has a first opening area at the first communication hole of the first main flow path and a first opening area at the second communication hole in accordance with the pressure of the fluid supplied from the fluid pressure actuator. A pilot lock valve provided movably in the axial direction so that at least one of the opening areas of 2 is changed. 2. The first sleeve is configured such that the at least one of the first opening area and the second opening area increases as the pressure of the fluid supplied from the fluid pressure actuator increases. Pilot lock valve as described. the first poppet is biased in a first direction in the axial direction;
the first sleeve is biased in a second direction opposite the first direction;
the driving member receiving the pilot pressure to move the first poppet in the second direction against the biasing force in the first direction;
The body portion directs a portion of the fluid supplied to the first port to the first valve accommodating portion so that the first sleeve moves against the biasing force in the second direction. 3. A pilot lock valve according to claim 1 or 2, having a supply fluid supply passage. the first valve housing is separated into first and second internal spaces by the first poppet and the first sleeve;
the fluid supply passage communicates with the first interior space and the second port communicates with the second interior space when the first poppet is driven in the second direction;
The first sleeve moves such that the at least one of the first and second opening areas increases as the difference between the pressure in the first internal space and the pressure in the second internal space increases. 4. The pilot lock valve of claim 3. the driving member includes a piston movably provided in the axial direction by receiving the pilot pressure;
A pilot lock valve according to any one of claims 1 to 4, wherein a damper space is formed between said first poppet and said piston. the second port is selectively connectable to one of the fluid reservoir and the fluid supply;
The first poppet receives the pressure of the fluid supplied to the second port by the fluid supply section, and connects the second port and the first port to the second port of the first sleeve. 6. The pilot lock valve according to any one of claims 1 to 5, wherein the pilot lock valve moves so as to form a second main flow path that communicates through the communication hole and the first communication hole. The body portion includes a second valve housing portion having a second inner circumferential surface extending in the axial direction, a third port connectable to the fluid pressure actuator, and one of the fluid storage portion and the fluid supply portion. further comprising a fourth port selectively connectable to
a second poppet having a second outer peripheral surface extending in the axial direction and reciprocally movable in the axial direction within the second valve housing;
A second valve having third and fourth communication holes and disposed between the second inner peripheral surface of the second valve accommodating portion and the second outer peripheral surface of the second poppet. It further comprises a sleeve and
The driving member uses the pressure of the fluid from the fluid supply section as the pilot pressure when the fluid storage section is connected to the second port and the fluid supply section is connected to the fourth port. receiving and driving the first poppet to receive fluid from the fluid supply when the fluid supply is connected to the second port and the fluid reservoir is connected to the fourth port; receiving pressure as the pilot pressure to drive the second poppet, wherein the third port communicates with the second valve accommodating portion through a third communicating opening of the second inner peripheral surface;
the fourth port communicates with the second valve accommodating portion at a fourth communication opening of the second inner peripheral surface;
The second poppet is arranged to separate the third port and the fourth port from each other at the second outer peripheral surface when not driven by the drive member, and is driven by the drive member. so that a third main flow path is formed that communicates the third port and the fourth port through the third communicating hole and the fourth communicating hole of the second sleeve when the move and
The second sleeve has a third opening area in the third communication hole of the third main flow path and a third opening area in the fourth communication hole in accordance with the pressure of the fluid supplied from the fluid pressure actuator. 7. The pilot lock valve according to claim 6, wherein the pilot lock valve is provided movably in the axial direction so that at least one of the opening areas of 4 is changed.

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