JP7204532B2 - flow control valve - Google Patents

Description

The present invention relates to a pressure-compensated flow control valve for use in hydraulic circuits.

Hydraulic actuators, particularly hydraulic motors used as drive sources for winches and the like, are switched between forward and reverse directions and shifted to a stopped state by changing the state of hydraulic pressure supplied to the hydraulic motor by means of a hydraulic circuit equipped with a directional switching valve or the like. It is generally realized by

In a device equipped with a hydraulic circuit for such a hydraulic motor, when hydraulic oil supplied from a pressure source (pump) that generates hydraulic pressure is directly introduced into the directional switching valve to control the operation of the hydraulic motor, the load on the hydraulic motor , the pressure of the hydraulic fluid going to the hydraulic motor also changes, and the amount of hydraulic fluid supplied to the hydraulic motor changes. However, there is a problem that the operating speed of the hydraulic motor decreases.

For this reason, a flow control valve with pressure compensation is provided on the upstream side of the direction switching valve so that even if the load (hydraulic pressure) of the hydraulic motor changes, the flow rate of the hydraulic oil supplied to the hydraulic motor is controlled by the direction switching valve. A mechanism has been introduced that does not change from the set value and is constant.
An example of such a pressure-compensated flow control valve is disclosed in Japanese Patent Application Laid-Open No. 11-63250.

JP-A-11-63250

Conventional pressure-compensated flow control valves are configured as described above, and regardless of changes in load (pressure), the flow rate of hydraulic oil supplied to actuators, etc. on the downstream side remains constant from the set value. it was possible.

On the other hand, when a plurality of actuators are provided and used individually, an actuator circuit that controls the actuator with such a flow control valve or direction switching valve is generally provided for each actuator. , there was a case where only one pressure source (pump) was used in common.

In order to appropriately operate a plurality of actuators using a single pressure source, a series circuit or a parallel circuit has been used as a circuit system for interconnecting a plurality of actuator circuits depending on the application.

In a series circuit, a plurality of actuator circuits are connected in series, hydraulic pressure from a pressure source is introduced into the most upstream circuit, and return oil from the upstream circuit is supplied to the feed oil passage of the downstream circuit. Also, in the parallel circuit, a plurality of actuator circuits are connected in parallel, and the hydraulic pressure from the pressure source is introduced in parallel to each actuator circuit.

When a flow control valve is installed in each of these series and parallel actuator circuits, the connection between the actuator circuits differs greatly between the series circuit and the parallel circuit. The body and casing were designed specifically for series circuits and parallel circuits.

In this way, although the functions of the flow control valves that appropriately adjust the flow rate in the actuator circuits are the same, flow control valves with different structures are used depending on whether the connection method of a plurality of actuator circuits is a series circuit or a parallel circuit. Since it was applied, there were many wasteful points in manufacturing the flow control valve in terms of the number of parts, etc., and improvement was desired.

The present invention has been devised to solve the above-mentioned problems. Regardless of whether the connection relationship of a plurality of fluid pressure circuits to which a valve device is to be applied is a series circuit or a parallel circuit, it can be dealt with simply by rearranging the valve body. To provide a flow regulating valve capable of reducing costs by sharing parts.

A flow control valve according to the present invention comprises a casing having a fluid inlet, an outlet, and a hole communicating with the inlet and the outlet; and a valve body that moves based on the pressure difference of the fluid in the fluid pressure circuit, and adjusts the flow rate of the fluid from the inlet to the outlet. The outlet portion includes a first outlet portion connected to the feed side flow path of the fluid pressure circuit and a second outlet portion connected to the return side flow path of the fluid pressure circuit, and the casing includes the hole. a first port that communicates between a portion and an inlet; two ports, and a third port provided on the other moving direction side of the valve body in the hole with respect to the first port and communicating the hole and the second outlet, and The casing applies fluid pressure at a first predetermined location in a feed-side channel of the fluid pressure circuit communicating with the first outlet portion so as to push the valve body in the one moving direction to the valve body. The fluid pressure at a second predetermined location separated from the first predetermined location in the feed-side channel by a predetermined throttle mechanism pushes the valve body in the other direction of movement with respect to the valve body. and the valve body is provided with a groove or recess that always keeps the first port and the second port in communication, and the first port and the third port can be communicated. However, when the valve body moves in the one direction of movement, the degree of communication between the first port and the third port is increased, and when it moves in the other direction of movement, the degree of communication between the first port and the third port is increased. A series circuit valve body provided with another groove or recess that reduces the degree of opening, or a valve body for a series circuit that allows communication between the first port and the second port and moves in the one movement direction to move the first Parallel circuit provided with a groove or recess that reduces the degree of opening of communication between the port and the second port and increases the degree of opening of communication between the first port and the second port when moved in the other direction of movement It is considered to be a valve body for

As described above, according to the present invention, three ports are provided in the hole through which the valve body passes in the casing of the valve device, and the opening degree of communication between the ports is controlled by the valve body according to the connection state of the fluid pressure circuit. The combination of two ports to be adjusted is selected from two combinations, and the two ports to be adjusted can be selected and determined only by rearranging two valve bodies, and the connection of the fluid pressure circuit By ensuring that the pressure compensation function is correctly exhibited by the movement of the appropriate valve element in each state, one common type of casing can be used for each connection state of the fluid pressure circuit, and the connection of the fluid pressure circuit It is not necessary to use a dedicated casing corresponding to the state, and only by recombining the valve body, a flow path connection state corresponding to each connection state of multiple fluid pressure circuits can be obtained, and manufacturing and installation are easy. The cost related to the device can be suppressed.

Further, in the flow rate control valve according to the present invention, the parallel circuit valve element sets a predetermined region without grooves or recesses in which the first port and the third port are always in a state of non-communication as needed. It is formed by

As described above, according to the present invention, the valve body is provided with a region having no grooves or recesses, and the first port and the third port are not communicated with each other by the valve body. The valve body structure alone can sufficiently ensure the state of eliminating the influence caused by part of the fluid flowing from the inlet portion toward the return side flow path of the valve device, and the structure of the valve device can be simplified.

In addition, in the flow control valve according to the present invention, the casing may be provided with a closing member that closes the second outlet portion to the return-side flow path of the fluid pressure circuit to put it in a non-communicating state, if necessary. It is.

As described above, according to the present invention, the closing member is attached to the casing, and the closing member disconnects the second outlet from the return flow path of the fluid pressure circuit. The configuration of the valve device can sufficiently ensure the state of eliminating the influence caused by part of the flow toward the return side flow path through the first port, the third port, and the second outlet portion, by arranging the closing member alone. can be simplified.

Further, in the flow control valve according to the present invention, if necessary, the valve body, which is the series circuit valve body, is disposed between the one groove or recess and the other groove or recess, between the first port in the casing and the It has an intermediate large-diameter portion that is slidable in the passage portion between the third port, and when the valve body moves in the one movement direction, the valve body slides against the passage portion between the first port and the third port in the casing. When the intermediate large-diameter portion separates to increase the degree of opening of the communication between the first port and the third port and moves in the other direction of movement, the portion of the passage between the first port and the third port in the casing The intermediate large-diameter portion approaches to reduce the degree of opening of the communication between the first port and the third port, and the end of the intermediate large-diameter portion facing the other groove or recess slides on the casing. A curved tapered portion whose diameter changes in a tapered manner from a contacting large-diameter portion toward the bottom portion of another groove or recess is formed, and at least the tapered portion of the valve body is formed in a direction orthogonal to the longitudinal direction of the valve body. A first through-hole is formed in at least the intermediate large-diameter portion of the valve body in a direction perpendicular to the longitudinal direction of the valve body and closer to the one groove or recess than the first through-hole. A second through hole is provided, and the second through hole intersects and communicates with a portion of the first through hole.

As described above, according to the present invention, the valve element disposed so as to be able to adjust the opening degree of communication between the first port and the third port of the casing has an intermediate large-diameter portion and a tapered portion continuous therewith. Then, a first through hole is provided in a predetermined range including at least the tapered portion of the valve body, and a second through hole is provided in a predetermined range centered on the intermediate large diameter portion. A second through-hole located closer to one groove or recess of the valve body than the hole crosses and communicates with the first through-hole, and the valve body closes the flow path between the first port and the third port. from the first port through the second through hole in the intermediate large diameter portion facing the first port and the first through hole facing another groove or recess leading to the third port. Fluid can be circulated to the third port side, and this circulating state continues while the second through hole faces the first port. The direction in which the fluid flows is different from the movement direction of the valve body, and the behavior of the valve body is less affected by the fluid. In addition to properly demonstrating the original adjustment function that maintains a constant flow rate of fluid regardless of pressure changes, the unstable behavior of the valve body is suppressed, resulting in sudden changes in fluid pressure that lead to abnormalities such as hunting on the downstream side. and increase the stability of the hydraulic circuit.

Further, by only providing two through-holes at predetermined positions of the valve body, the first port and the third port can be connected in a state where the valve body tries to close the flow path between the first port and the third port. An appropriate passage for circulating the working fluid can be formed between them, and a valve device with optimum characteristics can be easily obtained.

In addition, in the flow control valve according to the present invention, the valve body, which is the parallel circuit valve body, is arranged in the passage between the first port and the second port in the casing while being adjacent to the groove or the recess, if necessary. portion, and when the valve body moves in the one movement direction, the one large diameter portion approaches the passage portion between the first port and the second port in the casing. When the opening degree of the communication between the first port and the second port is reduced and the movement is made in the other moving direction, one large diameter portion is formed in the passage portion between the first port and the second port in the casing. is spaced apart to increase the degree of opening of the communication between the first port and the second port, and the end of one large diameter portion facing the groove or recess is provided from the large diameter portion slidingly contacting the casing. A curved tapered portion whose diameter tapers toward the bottom portion of the groove or recess is formed, and a first through hole is formed in at least the tapered portion of the valve body in a direction orthogonal to the longitudinal direction of the valve body. provided in at least the bottom portion of the groove or recess of the valve body in a direction perpendicular to the longitudinal direction of the valve body and further away from one large diameter portion of the valve body than the first through hole. A through-hole is provided, and the second through-hole intersects and communicates with a part of the first through-hole.

As described above, according to the present invention, the valve body disposed so as to be able to adjust the degree of opening of the communication between the first port and the second port of the casing has one large diameter portion and a tapered portion continuous therewith. a first through hole is provided in a predetermined range including at least the tapered portion of the valve body, and a second through hole is provided in a predetermined range including at least the bottom portion of the groove or the recess; A second through-hole positioned away from the one large-diameter portion of the through-hole crosses and communicates with the first through-hole, and the valve body is a flow path between the first port and the second port is about to be closed, from the first port to the second Fluid can flow to the port side, and this flowable state continues while the first through-hole faces the first port, so that the fluid flows from the first port to the second port immediately before closing. However, the movement direction of the valve disc is different, the behavior of the valve disc is less affected by the fluid, and the valve disc can be moved so as to perform pressure compensation correctly, regardless of changes in fluid pressure due to load fluctuations. In addition to properly exerting the original adjustment function to keep the flow rate of the fluid constant, it suppresses the unstable behavior of the valve body and prevents sudden changes in the fluid pressure that lead to abnormalities such as hunting on the downstream side. Increases circuit stability.

Further, by only providing two through-holes at predetermined locations of the valve body, the first port and the second port can be easily connected when the valve body tries to close the flow path between the first port and the second port. An appropriate passage for circulating the working fluid can be formed between them, and a valve device with optimum characteristics can be easily obtained.

1 is a schematic configuration explanatory diagram of a valve device using a flow control valve according to a first embodiment of the present invention; FIG. 1 is a schematic configuration diagram of a hydraulic circuit for driving a hydraulic motor including a flow control valve according to a first embodiment of the present invention; FIG. FIG. 2 is a circuit configuration explanatory diagram in the case of applying the valve device using the flow control valve according to the first embodiment of the present invention to a series circuit; FIG. 4 is an explanatory diagram of a state of communication between a pressure port and one load side port of a directional switching valve in the valve device using the flow control valve according to the first embodiment of the present invention; FIG. 4 is an explanatory view of the state of communication between the pressure port and the other load side port of the directional switching valve in the valve device using the flow control valve according to the first embodiment of the present invention; FIG. 4 is an explanatory diagram of a hydraulic fluid flow permission state between a first port and a third port in the flow rate regulating valve according to the first embodiment of the present invention; FIG. 4 is an explanatory diagram of an increased degree of communication opening between the first port and the third port in the flow regulating valve according to the first embodiment of the present invention; FIG. 5 is an explanatory view of a state where an intermediate large-diameter portion of the valve body of the flow rate control valve according to the first embodiment of the present invention starts sliding contact with the inner circumferential surface of the casing; FIG. 4 is an explanatory diagram of a non-communication state between the first port and the third port in the flow control valve according to the first embodiment of the present invention; FIG. 5 is a schematic configuration explanatory diagram of a valve device using a flow control valve according to a second embodiment of the present invention; FIG. 7 is a schematic configuration diagram of a hydraulic circuit for driving a hydraulic motor including a flow rate control valve according to a second embodiment of the present invention; FIG. 10 is a circuit configuration explanatory diagram in the case of applying the valve device using the flow control valve according to the second embodiment of the present invention to a parallel circuit; FIG. 10 is an explanatory diagram of the state of communication between the pressure port and one load side port of the direction switching valve in the valve device using the flow control valve according to the second embodiment of the present invention; FIG. 10 is an explanatory view of the state of communication between the pressure port and the other load side port of the directional switching valve in the valve device using the flow control valve according to the second embodiment of the present invention; FIG. 10 is an explanatory diagram of a hydraulic fluid flow permission state between a first port and a second port in a flow rate control valve according to a second embodiment of the present invention; FIG. 10 is an explanatory diagram of an increased opening degree of communication between the first port and the second port in the flow regulating valve according to the second embodiment of the present invention; FIG. 10 is an explanatory diagram of a start state of sliding contact of the valve body with the inner peripheral surface between the first port and the second port in the casing of the flow rate regulating valve according to the second embodiment of the present invention; FIG. 10 is an explanatory diagram of a non-communication state between the first port and the second port in the flow control valve according to the second embodiment of the present invention;

(First embodiment of the present invention)
A flow regulating valve according to a first embodiment of the present invention will be described below with reference to FIGS. 1 to 9. FIG. The present embodiment is applied to a valve device mainly comprising a directional switching valve that is provided in a hydraulic circuit that circulates hydraulic fluid to drive an actuator and that switches and adjusts the flow state of hydraulic fluid to the actuator. An example of a pressure-compensated flow control valve will be described.

In the above figures, the flow control valve 10 according to the present embodiment is used in combination with the directional switching valve 20 as an integral valve device 91. A casing 11 shared with the directional switching valve 20 and a It is a structure provided with the valve body 12 as a valve body for series circuits incorporated.

In this flow control valve 10, the position of the valve element 12 incorporated in the casing 11 is adjusted by the pressure of the hydraulic oil before and after the throttle mechanism in the latter stage and the elastic force of the spring 14, and the opening degree of the hydraulic oil flow path is changed. The hydraulic oil pressure is automatically controlled so that the downstream directional switching valve 20 can supply the hydraulic oil at a flow rate determined according to the position of the spool 21 to the load side without being affected by the load or the pressure source. The basic mechanism of pressure compensation is the same as that of a known pressure-compensated flow regulating valve, and detailed description thereof will be omitted.

The valve device 91 has a configuration in which a set of the direction switching valve 20 and the flow rate control valve 10 is integrated. It is connected to the motor 50, the pressure source 30 and the low pressure section 40, and controls the operation of the hydraulic motor 50 (see FIG. 2).

When a plurality of hydraulic actuator circuits for controlling the driving of the actuator (hydraulic motor 50) by the flow control valve 10 and the direction switching valve 20 are provided, the valve device 91 connects the plurality of circuits in series to form a series circuit. It is a valve device suitable for

When a plurality of hydraulic circuits (actuator circuits) composed of such valve devices 91 and hydraulic motors 50 are provided to form a series circuit, as shown in FIG. Needless to say.

The directional switching valve 20 used in combination with the flow rate control valve 10 includes a substantially cylindrical spool 21 that is longitudinally movably mounted in the common casing 11 with the flow rate control valve 10, and the spool position is manually switched by a lever. By switching the connection state between the pressure port 23 and the low pressure ports 24 and 25 provided in the casing 11 and the two load side ports 26 and 27, the supply and discharge of hydraulic oil to the load side hydraulic motor 50 is switched. It is a known valve.

The pressure port 23 of the directional switching valve 20 is connected to the flow control valve 10, and the low pressure ports 24 and 25 are connected to the low pressure section 40, respectively. are connected to the two flow paths 61 and 62 on the side, respectively.

The directional switching valve 20 has a spool position switching between a neutral state in which the two load side ports 26 and 27 are not connected to the pressure port 23 and the low pressure ports 24 and 25, respectively, and a state in which the pressure port 23 is connected to one load side. The port 26 is in communication with the low pressure port 25 in communication with the other load side port 27 to rotate the hydraulic motor 50 in the forward rotation direction. It is a three-position type configuration that can switch between a state in which the port 24 communicates with one of the load-side ports 26 and a state in which the hydraulic motor 50 is rotated in the reverse rotation direction.

Concave portions 21c and 21d are formed in both end portions of the large-diameter portion of the spool 21 facing the pressure port 23 in the neutral state. In a state in which either one of them is communicated with, the hydraulic fluid reaches the load side port 26 through the recess 21c from the pressure port 23, or reaches the load side port 27 through the recess 21d.

The casing 11 also serves as a casing for the directional switching valve 20. As a structure corresponding to the flow control valve 10, the casing 11 includes a hydraulic oil inlet 11a, hydraulic oil outlets 11b and 11c, and these inlets and outlets. It has a hole portion 11d communicating with the portion.

The inlet portion 11a is connected to a pressure source 30 such as a pump to introduce working oil. However, if the hydraulic circuit using this valve device 91 is the hydraulic circuit of the second and subsequent stages of the series circuit, the inlet portion 11a is connected to the hydraulic oil return passage of the upstream circuit. That is, when the upstream circuit is a similar hydraulic circuit, the low pressure port of the directional switching valve 20 in the upstream circuit is connected to this inlet portion 11a.

The outlets are a first outlet 11b connected to the pressure port 23 of the directional switching valve 20 as the feed side flow path (high pressure side flow path) of the fluid pressure circuit, and a return side flow path (low pressure side flow path) of the fluid pressure circuit. a second outlet 11c connected to the low pressure ports 24, 25 of the directional valve as a side flow path).
The hole portion 11d is a continuous hole into which the valve body 12 is inserted, and the valve body 12 is slidable in the continuous direction of the hole portion 11c.

The casing 11 further includes a first port 15 for communicating the hole portion 11d and the inlet portion 11a, and a moving direction side of the valve body 12 in the hole portion 11d with respect to the first port 15 (in FIG. 1, a second port 16 provided on the upper side) for communicating the hole portion 11d and the first outlet portion 11b; and lower side), and has a third port 17 that communicates the hole portion 11d and the second outlet portion 11d.

The casing 11 is also provided with a first pressure receiving portion 11 e facing one end of the valve body 12 and a second pressure receiving portion 11 f facing the other end of the valve body 12 . The first pressure receiving portion 11 e communicates with the second port 16 and the first outlet portion 11 b , and the second pressure receiving portion 11 f communicates with the secondary pressure passage 11 g provided in the casing 11 .

In this way, the casing 11 can apply the working oil pressure of the pressure port 23 communicating with the first outlet portion 11b from the first pressure receiving portion 11e to the valve body 12 so as to push the valve body in the one moving direction. and the hydraulic pressure extracted from the pressure port 23 is passed from the second pressure receiving portion 11f to the valve body 12 through the secondary pressure passage 11g having a throttle on the passage in the other moving direction. It is a mechanism that can be added so as to push the valve body 12 .

As a result, the hydraulic pressure of the pressure port 23 of the directional switching valve 20 communicating with the second port 16 (outlet portion 11b) of the casing 11 is introduced into the first pressure receiving portion 11e through the outlet portion 11b, and the directional switching valve 20 is introduced into the second pressure receiving portion 11f through the secondary pressure passage 11g having a throttle. Then, a first pressure receiving portion 11e into which the pressure of the pressure port 23 on the upstream side of the throttle of the secondary pressure passage 11g is introduced, and a second pressure receiving portion 11e into which the pressure on the downstream side of the throttle of the secondary pressure passage 11g is introduced. The valve element 12 moves so that the relationship between the pressure difference with the pressure receiving portion 11f and the elastic force of the spring 14 is maintained constant.

The valve body 12 is a valve body for a series circuit. A second large-diameter portion 12b located near the other end of the second pressure-receiving portion 11f and in sliding contact with the casing 11, and a second large-diameter portion 12b located between the first large-diameter portion 12a and the second large-diameter portion 12b. a first groove portion 12d located between the first large-diameter portion 12a and the intermediate large-diameter portion 12c; a second large-diameter portion 12b and the intermediate large-diameter portion 12c; It is the structure which has the 2nd groove part 12e located between the part 12c.

The second groove portion 12e of the valve body 12 is provided so that the first port 15 and the second port 16 are always in a communicating state even if the valve body 12 moves within the movable range. The first groove portion 12d of the valve body 12 enables communication between the first port 15 and the third port 17 of the casing 11, and when the valve body moves in the one moving direction, the first port 15 and the third port 17 are opened. The opening degree of communication between the first port 15 and the third port 17 is increased, and the opening degree of communication between the first port 15 and the third port 17 is decreased when moving in the other moving direction.

The grooves 12d and 12e of the valve body 12 are provided as grooves that are continuous in the circumferential direction of the valve body 12, and serve as flow paths for communicating between ports and for circulating hydraulic oil, but are not limited to grooves. For example, one or a plurality of recesses that are discontinuous in a groove shape in the circumferential direction of the valve body may be provided.

The side of the intermediate large-diameter portion 12c facing the first groove portion 12d is a tapered portion 12f formed as a curved portion whose diameter tapers off from the intermediate large-diameter portion 12c toward the small-diameter cylindrical portion at the bottom of the groove portion 12d. It is said that

The valve body 12 is slidably inserted into the casing 11 and receives hydraulic pressure introduced into the first pressure receiving portion 11e, hydraulic pressure introduced into the second pressure receiving portion 11f, and the spring 14. It moves based on the difference between force and force, adjusts the opening degree of communication between the inlet portion 11a and the second outlet portion 11c, and performs pressure compensation. It is the same, and detailed description is omitted.

The valve body 12 slides in the longitudinal direction of the valve body with respect to the casing 11, and the intermediate large diameter portion 12c approaches and slides against the narrow passage portion between the first port 15 and the third port 17 in the casing 11. By bringing them into contact with each other or separating them from each other, the degree of opening of communication between the first port 15 and the third port 17 is reduced or increased. The valve body 12 receives a pressing force from the first pressure-receiving portion 11e in the one moving direction, that is, the direction in which the valve body 12 increases the degree of opening of the communication between the first port 15 and the third port 17. , from the second pressure-receiving portion 11f and the spring 14, the pressing force is applied in the other moving direction, that is, in the direction in which the opening of the communication between the first port 15 and the third port 17 is reduced at the valve body 12. Become.

Two through-holes (first through-hole 12g and second through-hole 12h) are formed in the valve body 12 so as to intersect (intersect) and communicate with each other at the center of the valve body.
The first through-hole 12g is formed in a predetermined range extending in the longitudinal direction of the valve body 12 from the tapered portion 12d to part of the intermediate large diameter portion 12c in a direction orthogonal to the longitudinal direction of the valve body 12. As shown in FIG.

Further, the second through hole 12h extends in the longitudinal direction of the valve body 12 over a portion of the tapered portion 12d and a portion of the intermediate large diameter portion 12c, and extends over a portion of the predetermined range where the first through hole 12g exists. It is drilled in another predetermined overlapping range in a direction perpendicular to the longitudinal direction of the valve body 12 .

The second through-hole 12h is bored toward the intermediate large-diameter portion 12c so that the hole portion located at the intermediate large-diameter portion 12c is larger than the hole portion located at the tapered portion 12d. , is positioned closer to the other end of the valve body 12 than the first through hole 12g. The cross-sectional area of the second through-hole 12h is made smaller than the cross-sectional area of the first through-hole 12g.

Next, the operation state related to pressure compensation of the flow control valve based on the above configuration will be described. As a premise, in the flow control valve 10, the biasing force of the spring 14 is appropriately set so that communication between the first port 15 and the third port 17 of the flow control valve 10 is established in the neutral state of the direction switching valve 20. be in an acceptable state.

The pressure port 23 of the directional control valve 20 and the two load-side ports 26, 27 leading to the hydraulic motor-side circuit are not communicated, and the hydraulic motor 50 is stopped due to the hydraulic fluid not being supplied. The position of the spool 21 is switched by operation, the spool 21 is displaced in one direction (downward in FIG. 1), the pressure port 23 communicates with one load side port 26, and the low pressure port 25 communicates with the other load side port. When the port 27 is in communication (see FIG. 4), high-pressure hydraulic fluid from the pressure source 30 is always allowed to communicate between the first port 15 and the second port 16. 10 to the pressure port 23 of the directional control valve 20, and further through the concave portion 21c of the spool 21 to reach one of the load side ports 26. Hydraulic oil is supplied to the hydraulic motor 50 from one of the load-side ports 26 through one of the flow paths 61 including the counterbalance valve 65, thereby driving the hydraulic motor 50 in the forward rotation direction.

In this state, the hydraulic pressure of the pressure port 23 of the direction switching valve 20 is introduced into the first pressure receiving portion 11e of the flow control valve 10 through the first outlet portion 11b and the second port 16, and It is introduced into the second pressure receiving portion 11f of the flow control valve 10 via the side port 26 and the secondary pressure passage 11g having a throttle. In the flow regulating valve 10, the valve element 12 moves so as to maintain a constant relationship between the pressure difference between the first pressure receiving portion 11e and the second pressure receiving portion 11f and the elastic force of the spring 14. The opening degree of communication between the first port 15 and the third port 17 is adjusted.

In the directional switching valve 20, when the position of the spool 21 is manually switched from the neutral state, the spool 21 shifts in the other direction (upward in FIG. 1), and the pressure port 23 communicates with the other load side port 27. , and in a state where the low-pressure port 24 communicates with one of the load-side ports 26 (see FIG. 5), high-pressure hydraulic oil from the pressure source 30 advances to the pressure port 23 of the directional switching valve 20 through the flow control valve 10, It reaches the other load side port 27 via the recess 21d. Hydraulic motor 50 is driven in the reverse rotation direction by supplying the hydraulic fluid coming out of load side port 27 to hydraulic motor 50 through the other flow path 62 .

In this state, the hydraulic pressure of the pressure port 23 of the direction switching valve 20 is introduced into the first pressure receiving portion 11e of the flow control valve 10 through the first outlet portion 11b and the second port 16, and the other load It is introduced into the second pressure receiving portion 11f through the side port 27 and the secondary pressure passage 11g having a throttle. In the flow control valve 10, similarly to the case of the forward rotation of the hydraulic motor 50, the relationship between the pressure difference between the first pressure receiving portion 11e and the second pressure receiving portion 11f and the elastic force of the spring 14 is kept constant. The valve body 12 moves so as to adjust the opening degree of communication between the first port 15 and the third port 17 .

In the flow control valve 10, the communication between the first port 15 and the second port 16 is always permitted, and the hydraulic oil that has flowed into the first port 15 is directed to the valve body 12 facing the first port 15. It reaches the second port 16 through the second groove 12e (see FIGS. 6, 7, 8 and 9).

On the other hand, in a state in which communication between the first port 15 and the third port 17 is allowed, part of the hydraulic oil that has flowed into the first port 15 is transferred to the intermediate large diameter portion 12c facing the first port 15. , and reaches the third port 17 through a gap around the taper portion 12f and the first groove portion 12d (see FIGS. 6, 7 and 8).

If the load on the hydraulic motor 50 increases and the pressure of the hydraulic fluid in the flow path on the supply side to the hydraulic motor 50 increases, the hydraulic fluid in the secondary pressure passage 11g communicating with the load side port of the direction switching valve 20 Pressure also increases. The pressure of the hydraulic fluid introduced into the second pressure receiving portion 11f and the elastic force of the spring 14 press the other end of the valve body 12, and the pressure of the hydraulic fluid introduced into the first pressure receiving portion 11e pushes the valve body. By exceeding the force pushing one end of 12, the valve body 12 moves in the direction (left side in FIG. 6) to decrease the degree of opening of the communication between the first port 15 and the third port 17. Specifically, the valve body 12 moves so as to bring the intermediate large-diameter portion 12c closer to the narrow passage portion between the first port 15 and the third port 17 in the casing 11, and accordingly, The clearance around the tapered portion 12f is reduced to reduce the opening degree of communication between the first port 15 and the third port 17. - 特許庁

In this way, the opening degree of the communication between the first port 15 and the third port 17 is reduced by the valve body 12 , so that the flow from the first port 15 of the flow control valve 10 to the low pressure port 25 of the directional control valve 20 via the third port 17 . By reducing the ratio (flow rate) of the hydraulic fluid directed to the second port 16, the pressure of the hydraulic fluid reaching the first outlet portion 11b and the pressure port 23 can be increased, and the pressure of the hydraulic fluid introduced into the first pressure receiving portion 11e can be increased. The force that presses the one end of the valve body 12 due to the hydraulic pressure also increases. Ultimately, the force pushing the other end of the valve body 12 and the force pushing the one end of the valve body 12 are balanced to bring the valve body 12 into an equilibrium state where the front side and the rear side of the secondary pressure passage 11g having a throttle are formed. By keeping the pressure difference between the two sides constant, the flow rate of the hydraulic oil flowing from the flow control valve 10 to the directional switching valve 20 can be made constant. can be kept constant regardless of the load increase.

On the other hand, when the pressure of the hydraulic fluid flowing into the first port 15 of the flow control valve 10 becomes relatively large, such as when the load of the hydraulic motor 50 suddenly decreases or when the hydraulic motor 50 is started, the flow control valve The working oil pressure at the second port 16 (outlet portion 11b) of 10 increases with respect to the working oil pressure at the load side port on the subsequent stage side. Contrary to the case of the load increase, the force pushing the one end portion of the valve body 12 by the hydraulic pressure introduced into the first pressure receiving portion 11e is applied to the hydraulic pressure introduced into the second pressure receiving portion 11f. and the elastic force of the spring 14 exceeds the force that pushes the other end of the valve body 12, so that the valve body 12 moves in a direction that increases the opening of the communication between the first port 15 and the third port 17 (Fig. 6 to the right). Specifically, the valve body 12 moves so as to separate the intermediate large-diameter portion 12c from the narrow passage portion between the first port 15 and the third port 17 in the casing 11, and accordingly, The gap around the tapered portion 12f is increased to increase the degree of opening of communication between the first port 15 and the third port 17 (see FIG. 7).

In this way, by increasing the opening degree of communication between the first port 15 and the third port 17 with the valve body 12, the direction is switched from the first port 15 of the flow control valve 10 via the third port 17 and the second outlet portion 11c. By increasing the proportion (flow rate) of hydraulic fluid directed to the low pressure port 25 of the valve 20, the pressure of the hydraulic fluid reaching the first outlet 11b and the pressure port 23 from the second port 16 can be reduced. The pressure of the hydraulic fluid introduced into the pressure receiving portion 11e also reduces the force that pushes the one end portion of the valve body 12. As shown in FIG. Ultimately, the force pushing the other end of the valve body 12 and the force pushing the one end of the valve body 12 are balanced to bring the valve body 12 into an equilibrium state where the front side and the rear side of the secondary pressure passage 11g having a throttle are formed. By keeping the pressure difference between the two sides constant, the flow rate of the hydraulic oil flowing from the flow control valve 10 to the directional switching valve 20 can be made constant. can be made constant.

When the load on the hydraulic motor 50 suddenly increases or when the hydraulic motor 50 suddenly stops, the pressure of the hydraulic oil in the flow path on the supply side to the hydraulic motor 50 suddenly increases. The hydraulic fluid pressure in the secondary pressure passage 11g communicating with the load side port becomes significantly higher than the hydraulic fluid pressure in the second port 16 and the first outlet portion 11b of the flow control valve 10 on the upstream side. When the force that pushes the other end of the valve body 12 at the pressure receiving portion 11f of the first pressure receiving portion 11e greatly exceeds the force that pushes the one end of the valve body 12 at the first pressure receiving portion 11e, the valve body 12 moves between the first port 15 and the third port. A state is created in which the channel between the port 17 and the port 17 is about to be closed.

In this case, the valve body 12 is arranged so that the intermediate large diameter portion 12c approaches the narrow passage portion between the first port 15 and the third port 17 in the casing 11, and the inner peripheral surface of the casing forming the passage portion. It moves so as to bring the intermediate large diameter portion 12c into sliding contact.

In this process, until the boundary portion between the intermediate large-diameter portion 12c and the tapered portion 12f of the valve body 12 reaches the end of the first port 15, the hydraulic oil flows into the tapered portion 12f of the valve body 12 facing the first port 15. It is in a state of flow reaching the third port 17 through the surrounding gap and the first groove portion 12d. When it starts sliding on the inner peripheral surface of the casing between the port 15 and the third port 17 (see FIG. 8), the second through hole 12h of the intermediate large diameter portion 12a facing the first port 15, the tapered portion 12d and the casing 11 and the first through hole 12g facing the first groove portion 12d, the hydraulic fluid is transferred from the first port 15 to the third port 17.

As the valve body 12 moves and the second through hole 12h reaches a position where it does not face the first port 15, there is no communication between the first port 15 and the third port 17, and hydraulic oil does not flow. (See FIG. 9).

In this way, immediately before the opening degree of the communication between the first port 15 and the third port 17 is set to 0 by the valve body 12, the state in which the hydraulic oil flows through the second through-hole 12h and the first through-hole 12g is By continuing while the second through-hole 12h faces the first port 15, the unstable behavior of the valve body 12 immediately before closing the flow path is suppressed, leading to abnormalities such as hunting on the downstream side. Prevents sudden changes in hydraulic pressure and increases the stability of the hydraulic circuit.

When the communication between the first port 15 and the third port 17 is cut off due to the movement of the valve body 12, and the hydraulic fluid does not flow from the first port 15 to the third port 17, the flow from the second port 16 to the first The pressure of the hydraulic fluid reaching the outlet portion 11b and the pressure port 23 increases, and the pressure of the hydraulic fluid introduced into the first pressure receiving portion 11e also increases the force pushing the one end portion of the valve body 12 . As a result, the valve body 12 again moves in a direction (to the right in FIG. 6) to increase the degree of opening of the communication between the first port 15 and the third port 17, and the first port 15 faces the second through hole 12h. Then, through the second through-hole 12h and the first through-hole 12g, the hydraulic oil can flow from the first port 15 to the first groove portion 12d side, or the first port 15 in the casing 11 and the The communication between the first port 15 and the third port 17 is resumed by separating the intermediate large diameter portion 12c from the narrow passage portion between the first port 15 and the third port 17.例文帳に追加

Ultimately, similarly to the above, the force pushing the other end of the valve body 12 and the force pushing the one end of the valve body 12 are balanced to reach an equilibrium state where the valve body 12 stops, and the upstream side of the secondary pressure passage 11g having a throttle. By keeping the pressure difference between the pressure side and the rear stage side constant, the flow rate of the hydraulic oil flowing from the flow control valve 10 to the directional switching valve 20 can be made constant, and at the same time, the flow rate of the hydraulic oil supplied to the hydraulic motor 50 can be kept constant. can be constant.

Thus, the flow control valve according to the present embodiment has three ports 15, 16, and 17 provided in the hole through which the valve body 12 passes in the casing 11, and the first port 15 and the third port 17 is adjusted by the valve body 12, and the pressure compensation due to the movement of the valve body 12 is achieved only by the characteristics of the shape of the valve body 12 adapted to the series circuit. Since the function is properly exhibited, the casing 11 common to the parallel circuit can be used for the flow rate adjustment function with pressure compensation, and there is no need to use a dedicated casing corresponding to the connection state of the hydraulic circuit. In addition, only by reassembling the valve body, a flow path connection state corresponding to each connection state of a plurality of hydraulic circuits can be obtained.

A first through hole 12g and a second through hole 12h intersecting the first through hole 12g are provided in a predetermined range of the valve body 12, and the valve body 12 closes the flow path between the first port 15 and the third port 17. Hydraulic oil can flow from the first port 15 to the third port 17 side through the second through hole 12h facing the first port 15 and the first through hole 12g communicating therewith. Since this circulating state continues while the second through hole 12h faces the inlet portion 11a, the direction in which the hydraulic oil circulates from the first port 15 to the third port 17 side immediately before closing is Since the movement direction of the valve body 12 is different from the movement direction of the valve body 12, the behavior of the valve body 12 is less likely to be affected by the flow of hydraulic fluid, the valve body 12 can be moved so that pressure compensation can be performed correctly, and the hydraulic fluid pressure accompanying load fluctuations In addition to suppressing unstable behavior of the valve body 12, operation that leads to abnormalities such as hunting on the downstream side of the flow control valve. Prevents sudden changes in hydraulic pressure and increases the stability of the hydraulic circuit.

Further, by only providing two through-holes at predetermined locations of the valve body 12, the first port 15 can be opened when the valve body 12 attempts to close the flow path between the first port 15 and the third port 17. , and the third port 17, it is possible to easily obtain a valve device having optimum characteristics.

(Second embodiment of the present invention)
A flow control valve according to a second embodiment of the present invention will be described with reference to FIGS. 10 to 18. FIG.

In the above figures, the flow control valve 10 according to the present embodiment is used in combination with the directional switching valve 20 as an integral valve device 92. A casing 11 shared with the directional switching valve 20 and a It is a structure provided with the valve body 13 as a valve body for parallel circuits incorporated.

In this flow control valve 10, the position of the valve element 13 incorporated in the casing 11 is adjusted by the pressure of the hydraulic oil before and after the throttle mechanism in the latter stage and the elastic force of the spring 14, and the opening degree of the hydraulic oil flow path is changed. The hydraulic oil pressure is automatically controlled so that the downstream directional switching valve 20 can supply the hydraulic oil at a flow rate determined according to the position of the spool 21 to the load side without being affected by the load or the pressure source. The basic mechanism of pressure compensation is the same as that of a known pressure-compensated flow regulating valve, and detailed description thereof will be omitted.

The valve device 92 has a configuration in which a set of the direction switching valve 20 and the flow rate control valve 10 is integrated. It is connected to the motor 50, the pressure source 30 and the low pressure section 40, and controls the operation of the hydraulic motor 50 (see FIG. 11).

When a plurality of hydraulic actuator circuits are provided for controlling the driving of the actuator (hydraulic motor 50) by the flow control valve 10 and the direction switching valve 20, the valve device 92 connects these circuits in parallel to form a parallel circuit. It is a valve device suitable for

When a plurality of hydraulic circuits (actuator circuits) composed of such valve devices 92 and hydraulic motors 50 are provided to form a parallel circuit, as shown in FIG. parallel).

The directional switching valve 20 used in combination with the flow rate control valve 10 includes a substantially cylindrical spool 21 that is longitudinally movably mounted in the common casing 11 with the flow rate control valve 10, and the spool position is manually switched by a lever. By switching the connection state between the pressure port 23 and the low pressure ports 24 and 25 provided in the casing 11 and the two load side ports 26 and 27, the supply and discharge of hydraulic oil to the load side hydraulic motor 50 is switched. It is a known valve.

The pressure port 23 of the directional switching valve 20 is connected to the flow control valve 10, and the low pressure ports 24 and 25 are connected to the low pressure section 40, respectively. are connected to the two flow paths 61 and 62 on the side, respectively.

The directional switching valve 20 has a spool position switching between a neutral state in which the two load side ports 26 and 27 are not connected to the pressure port 23 and the low pressure ports 24 and 25, respectively, and a state in which the pressure port 23 is connected to one load side. The port 26 is in communication with the low pressure port 25 in communication with the other load side port 27 to rotate the hydraulic motor 50 in the forward rotation direction. It is a three-position type configuration that can switch between a state in which the port 24 communicates with one of the load-side ports 26 and a state in which the hydraulic motor 50 is rotated in the reverse rotation direction.

Concave portions 21c and 21d are formed in both end portions of the large-diameter portion of the spool 21 facing the pressure port 23 in the neutral state. In a state in which either one of them is communicated with, the hydraulic fluid reaches the load side port 26 through the recess 21c from the pressure port 23, or reaches the load side port 27 through the recess 21d.

The casing 11 also serves as a casing for the directional switching valve 20, as in the first embodiment. 11c and a hole 11d communicating with the inlet and outlet.

The inlet portion 11a is connected to a pressure source 30 such as a pump to introduce working oil. The outlets are a first outlet 11b connected to the pressure port 23 of the directional switching valve 20 as the feed side flow path (high pressure side flow path) of the fluid pressure circuit, and a return side flow path (low pressure side flow path) of the fluid pressure circuit. a second outlet 11c connected to the low pressure ports 24, 25 of the directional valve as a side flow path).
The hole portion 11d is a continuous hole into which the valve body 13 is inserted, and the valve body 13 can slide in the continuous direction of the hole portion 11d.

The casing 11 further includes a first port 15 for communicating the hole portion 11d and the inlet portion 11a, and a moving direction side of the valve body 13 in the hole portion 11d with respect to the first port 15 (in FIG. 10, a second port 16 provided on the upper side) for communicating the hole portion 11d and the first outlet portion 11b; and lower side), and has a third port 17 that communicates the hole portion 11d and the second outlet portion 11c.

The casing 11 is also provided with a first pressure receiving portion 11 e facing one end of the valve body 13 and a second pressure receiving portion 11 f facing the other end of the valve body 13 . The first pressure receiving portion 11 e communicates with the second port 16 and the first outlet portion 11 b , and the second pressure receiving portion 11 f communicates with the secondary pressure passage 11 g provided in the casing 11 .

Thus, the casing 11 can apply the hydraulic pressure of the pressure port 23 communicating with the first outlet portion 11b from the first pressure receiving portion 11e to the valve body 13 so as to push the valve body in the one moving direction. and the hydraulic pressure extracted from the pressure port 23 is passed from the second pressure receiving portion 11f to the valve body 13 in the other moving direction through the secondary pressure passage 11g having a throttle provided on the passage. It is a mechanism that can be added so as to push the valve body 13 .

As a result, the hydraulic pressure of the pressure port 23 of the directional switching valve 20 communicating with the second port 16 (outlet portion 11b) of the casing 11 is introduced into the first pressure receiving portion 11e through the outlet portion 11b, and the directional switching valve 20 is introduced into the second pressure receiving portion 11f through the secondary pressure passage 11g having a throttle. Then, a first pressure receiving portion 11e into which the pressure of the pressure port 23 on the upstream side of the throttle of the secondary pressure passage 11g is introduced, and a second pressure receiving portion 11e into which the pressure on the downstream side of the throttle of the secondary pressure passage 11g is introduced. The valve element 13 moves so that the relationship between the pressure difference with the pressure receiving portion 11f and the elastic force of the spring 14 is maintained constant.

The valve body 13 is a valve body for a parallel circuit. A second large diameter portion 13b located near the other end on the side of the second pressure receiving portion 11f and in sliding contact with the casing 11, and located between the first large diameter portion 13a and the second large diameter portion 13b. It is the structure which has the groove part 13c.

The first large-diameter portion 13a of the valve body 13 keeps the first port 15 and the third port 17 of the casing 11 out of communication even if the valve body 13 moves within the movable range. It is formed as a post with no grooves or recesses for passing.

The groove portion 13c of the valve body 13 reduces the degree of opening of the communication between the first port 15 and the second port 16 when moving in the one moving direction, and reduces the opening degree of communication between the first port 15 and the second port 16 when moving in the other moving direction. It is provided so as to increase the degree of opening of communication between the two ports 16 .

The side of the first large-diameter portion 13a facing the groove portion 13c is a tapered portion formed as a curved portion whose diameter tapers off from the first large-diameter portion 13a toward the small-diameter cylindrical portion at the bottom of the groove portion 13c. 13d.

The valve body 13 is slidably inserted into the casing 11 and receives hydraulic fluid pressure introduced into the first pressure receiving portion 11e, hydraulic fluid pressure introduced into the second pressure receiving portion 11f, and the spring 14. It moves based on the difference between force and force, adjusts the opening of the communication between the inlet portion 11a and the first outlet portion 11b, and performs pressure compensation. It is the same, and detailed description is omitted.

The valve body 13 slides in the longitudinal direction of the valve body with respect to the casing 11 so that the first large diameter portion 13a approaches the narrow passage portion between the first port 15 and the second port 16 in the casing 11. , slidably contact or separate from each other to decrease or increase the opening degree of communication between the first port 15 and the second port 16 . The valve body 13 receives a pressing force from the first pressure receiving portion 11e in a direction that reduces the opening degree of the communication between the first port 15 and the second port 16 at the valve body 13, and the second pressure receiving portion 11f and the second pressure receiving portion 11f and The valve body 13 receives a pressing force from the spring 14 in a direction to increase the degree of opening of communication between the first port 15 and the second port 16 .

Two through-holes (first through-hole 13g and second through-hole 13h) are formed in the valve body 13 so as to intersect (intersect) and communicate with each other at the center of the valve body.
The first through hole 13g extends perpendicularly to the longitudinal direction of the valve body 13 in a predetermined range extending from the tapered portion 13d in the longitudinal direction of the valve body 13 to the first large diameter portion 13a and the groove bottom of the groove portion 13c. Perforated as orientation.

In addition, the second through hole 13h extends in the longitudinal direction of the valve body 13 from part of the tapered portion 13d to the groove bottom of the groove portion 13c, and partially overlaps the predetermined range where the first through hole 13g exists. It is drilled in a predetermined range in a direction orthogonal to the longitudinal direction of the valve body 13 .

The second through hole 13h is formed so as to be biased toward the groove portion 13c so that the hole portion positioned at the groove bottom portion of the groove portion 13c is larger than the hole portion positioned at the tapered portion 13d. is located closer to the other end of the valve body 13 than the through hole 13g. The cross-sectional area of the second through-hole 13h is made larger than the cross-sectional area of the first through-hole 13g.

Next, the operation state related to pressure compensation of the flow control valve based on the above configuration will be described. As a premise, in the flow control valve 10, the biasing force of the spring 14 is appropriately set so that communication between the first port 15 and the second port 16 of the flow control valve 10 is established in the neutral state of the direction switching valve 20. shall be in an acceptable state.

The pressure port 23 of the directional control valve 20 and the two load-side ports 26, 27 leading to the hydraulic motor-side circuit are not communicated, and the hydraulic motor 50 is stopped due to the hydraulic fluid not being supplied. The position of the spool 21 is switched by operation, the spool 21 is displaced in one direction (downward in FIG. 10), the pressure port 23 communicates with one load side port 26, and the low pressure port 25 communicates with the other load side port. When the port 27 is communicated (see FIG. 13), the high-pressure hydraulic fluid from the pressure source 30 is allowed to communicate between the first port 15 and the second port 16 of the flow control valve 10. It advances to the pressure port 23 of the directional switching valve 20 through the directional control valve 20, and reaches one of the load side ports 26 via the concave portion 21c. Hydraulic oil is supplied from one of the load-side ports 16 to the hydraulic motor 50 through one of the flow paths 61 including the counterbalance valve 65, thereby driving the hydraulic motor 50 in the forward rotation direction.

In this state, the hydraulic pressure of the pressure port 23 of the direction switching valve 20 is introduced into the first pressure receiving portion 11e of the flow control valve 10 through the first outlet portion 11b and the second port 16, and It is introduced into the second pressure receiving portion 11f of the flow control valve 10 via the side port 26 and the secondary pressure passage 11g having a throttle. In the flow regulating valve 10, the valve element 13 moves so as to maintain a constant relationship between the pressure difference between the first pressure receiving portion 11e and the second pressure receiving portion 11f and the elastic force of the spring 14. Adjust the opening of communication between the first port 15 and the second port 16 .

In the directional switching valve 20, when the position of the spool 21 is manually switched from the neutral state, the spool 21 shifts in the other direction (upward in FIG. 10), and the pressure port 23 communicates with the other load side port 27. , and in a state where the low-pressure port 24 communicates with one of the load-side ports 26 (see FIG. 14), high-pressure hydraulic fluid from the pressure source 30 advances to the pressure port 23 of the directional switching valve 20 through the flow control valve 10, It reaches the other load side port 27 via the recess 21d. Hydraulic motor 50 is driven in the reverse rotation direction by supplying the hydraulic fluid coming out of load side port 27 to hydraulic motor 50 through the other flow path 62 .

In this state, the hydraulic pressure of the pressure port 23 of the direction switching valve 20 is introduced into the first pressure receiving portion 11e of the flow control valve 10 through the first outlet portion 11b and the second port 16, and the other load It is introduced into the second pressure receiving portion 11f through the side port 27 and the secondary pressure passage 11g having a throttle. In the flow control valve 10, similarly to the case of the forward rotation of the hydraulic motor 50, the relationship between the pressure difference between the first pressure receiving portion 11e and the second pressure receiving portion 11f and the elastic force of the spring 14 is kept constant. The valve body 13 moves so as to adjust the opening degree of communication between the first port 15 and the second port 16 .

In the flow rate regulating valve 10, the hydraulic oil flowing into the first port 15 is allowed to communicate between the first port 15 and the second port 16, and the valve body 13 facing the first port 15 reaches the second port 16 through the gap around the tapered portion 13d and the groove portion 13c (see FIGS. 15 and 16).

If the load on the hydraulic motor 50 increases and the pressure of the hydraulic fluid in the flow path on the supply side to the hydraulic motor 50 increases, the hydraulic fluid in the secondary pressure passage 11g communicating with the load side port of the direction switching valve 20 Pressure also increases. The pressure of the hydraulic fluid introduced into the second pressure receiving portion 11f and the elastic force of the spring 14 press the other end of the valve body 13, and the pressure of the hydraulic fluid introduced into the first pressure receiving portion 11e pushes the valve body. By exceeding the force pushing the one end of 13, the valve body 13 moves in the direction (left side in FIG. 15) to increase the degree of opening of the communication between the first port 15 and the second port 16. Specifically, the valve body 13 moves so as to separate the first large-diameter portion 13a from the narrow passage portion between the first port 15 and the second port 16 in the casing 11. 16 to increase the opening of communication between the first port 15 and the second port 16 (see FIG. 16).

In this way, the opening degree of communication between the first port 15 and the second port 16 is increased by the valve body 13, and the pressure loss associated with the flow between the first port 15 and the second port 16 of the flow control valve 10 is reduced. , the pressure of the hydraulic fluid reaching the first outlet portion 11b and the pressure port 23 from the second port 16 can be increased, and the pressure of the hydraulic fluid introduced into the first pressure receiving portion 11e pushes one end of the valve body 13. growing. Ultimately, the force pushing the other end of the valve body 13 and the force pushing the one end of the valve body 13 are balanced to bring the valve body 13 into an equilibrium state where the front side and the rear side of the secondary pressure passage 11g having a throttle are formed. By keeping the pressure difference between the two sides constant, the flow rate of the hydraulic oil flowing from the flow control valve 10 to the directional switching valve 20 can be made constant. can be kept constant regardless of the load increase.

On the other hand, when the pressure of the hydraulic fluid flowing into the first port 15 of the flow control valve 10 becomes relatively large, such as when the load of the hydraulic motor 50 suddenly decreases or when the hydraulic motor 50 is started, the flow control valve The working oil pressure at the second port 16 (outlet portion 11b) of 10 increases with respect to the working oil pressure at the load side port on the subsequent stage side. Contrary to the case of the load increase, the force pushing the one end of the valve body 13 by the hydraulic pressure introduced into the first pressure receiving portion 11e is applied to the hydraulic pressure introduced into the second pressure receiving portion 11f. and the elastic force of the spring 14 exceeds the force that pushes the other end of the valve body 13, so that the valve body 13 moves in a direction that reduces the opening of the communication between the first port 15 and the second port 16 (Fig. 15 to the right). Specifically, the valve body 13 moves so as to bring the first large diameter portion 13a closer to the narrow passage portion between the first port 15 and the second port 16 in the casing 11. , the gap around the tapered portion 13d is reduced, and the degree of opening of communication between the first port 15 and the second port 16 is reduced.

In this way, the pressure loss associated with the flow between the first port 15 and the second port 16 of the flow control valve 10 is increased to the extent that the valve body 13 reduces the degree of communication between the first port 15 and the second port 16. , the pressure of the hydraulic fluid reaching the first outlet portion 11b and the pressure port 23 can be reduced, and the force of the hydraulic fluid pressure introduced to the first pressure receiving portion 11e to push the one end portion of the valve body 13 is also reduced. Ultimately, the force pushing the other end of the valve body 13 and the force pushing the one end of the valve body 13 are balanced to bring the valve body 13 into an equilibrium state where the front side and the rear side of the secondary pressure passage 11g having a throttle are formed. By keeping the pressure difference between the two sides constant, the flow rate of the hydraulic oil flowing from the flow control valve 10 to the directional switching valve 20 can be made constant. can be made constant.

Note that when the hydraulic motor 50 is started, the pressure of the hydraulic fluid flowing into the first port 15 of the flow rate regulating valve 10 rapidly increases, and the hydraulic fluid in the second port 16 and the first outlet portion 11b in the communicating state increases. The pressure significantly increases relative to the hydraulic pressure in the load side port of the direction switching valve 20 on the later stage side and in the secondary pressure passage 11g communicating therewith, and the first pressure receiving portion 11e presses one end of the valve body 13. However, when the second pressure receiving portion 11f greatly exceeds the force pushing the other end of the valve body 13, the valve body 13 tries to close the flow path between the first port 15 and the second port 16. state.

In this case, the valve body 13 causes the first large diameter portion 13a to approach the narrow passage portion between the first port 15 and the second port 16 in the casing 11, and furthermore, the first port 15 and the second port 16 so that the first large-diameter portion 13a is brought into sliding contact with the inner circumferential surface of the casing.

In this process, until the boundary portion between the first large-diameter portion 13 a and the tapered portion 13 d of the valve body 13 reaches the end of the first port 15 , the hydraulic oil flows through the tapered portion of the valve body 13 facing the first port 15 . The flow is in a state of reaching the second port 16 through the gap around the portion 13d and the groove portion 13c. When it starts sliding on the inner peripheral surface of the casing between the first port 15 and the second port 16 (see FIG. 17), the first through hole 13g partially facing the first port 15, the tapered portion 13d and the casing 11 Hydraulic oil flows from the first port 15 to the second port 16 through the gap portion between and the second through hole 13h facing the groove portion 13c.

Then, as the first through hole 13g reaches a position not facing the first port 15 due to the movement of the valve body 13, the first port 15 and the second port 16 are not communicated at all, and hydraulic oil does not flow. (See FIG. 18).

Immediately before the opening degree of communication between the first port 15 and the second port 16 is set to 0 by the valve body 13, the state in which hydraulic oil flows through the first through-hole 13g and the second through-hole 13h is the first state. By continuing while the through-hole 13g faces the first port 15, the unstable behavior of the valve body 13 is suppressed immediately before the flow path is closed, and the working oil pressure that leads to abnormalities such as hunting on the rear stage side can prevent sudden changes in pressure and increase the stability of the hydraulic circuit.

With the movement of the valve body 13, the communication between the first port 15 and the second port 16 is cut off, and the flow of hydraulic oil from the first port 15 to the second port 16 is stopped, so that the second port 16 The force that presses the one end of the valve body 13 in the communicating first pressure receiving portion 11e also becomes small as described above, and the force that presses the other end of the valve body 13 in the second pressure receiving portion 11f relatively exceeds this force. As a result, the valve body 13 again moves in a direction (left side in FIG. 15) to increase the opening degree of communication between the first port 15 and the second port 16, and the first port 15 and the second port 16 in the casing 11 move. The first large-diameter portion 13a is separated from the narrow passage portion between and the communication between the first port 15 and the second port 16 is resumed.

Ultimately, similarly to the above, the force pushing the other end of the valve body 13 and the force pushing the one end of the valve body 13 are balanced to bring the valve body 13 into an equilibrium state where the valve body 13 stops, and the front side and the rear side of the throttle portion are separated. By keeping the pressure difference constant, the flow rate of hydraulic oil flowing from the flow control valve 10 to the direction switching valve 20 can be made constant, and at the same time, the flow rate of hydraulic oil supplied to the hydraulic motor 50 can be made constant. .

Thus, the flow control valve according to the present embodiment has three ports 15, 16, and 17 provided in the hole through which the valve body 13 passes in the casing 11, and the first port 15 and the second port 16 is adjusted by the valve body 13, and the pressure compensation due to the movement of the valve body 13 is achieved only by the feature of the shape of the valve body 13 adapted to the parallel circuit. Since the function is correctly exhibited, the casing 11 common to the series circuit can also correspond to the function of flow rate adjustment with pressure compensation, and there is no need to use a dedicated casing corresponding to the connection state of the hydraulic circuit. In addition, only by reassembling the valve body, a flow path connection state corresponding to each connection state of a plurality of hydraulic circuits can be obtained.

A first through hole 13g and a second through hole 13h intersecting the first through hole 13g are provided in a predetermined range of the valve body 13, and the valve body 13 closes the flow path between the first port 15 and the second port 16. Hydraulic oil can flow from the first port 15 to the second port 16 side through the first through hole 13g facing the first port 15 and the second through hole 13h communicating therewith. Since this circulating state continues while the first through hole 13g faces the first port 15, the direction in which the hydraulic oil flows from the first port 15 to the second port 16 side immediately before closing is , the movement direction of the valve body 13 is different, the behavior of the valve body 13 is less likely to be affected by the flow of hydraulic fluid, the valve body 13 can be moved so as to perform pressure compensation correctly, and the hydraulic fluid accompanying load fluctuations The original adjustment function of keeping the flow rate of the hydraulic oil constant regardless of pressure changes can be properly exhibited, and the unstable behavior of the valve body 13 is suppressed, leading to abnormalities such as hunting on the downstream side of the flow rate adjustment valve. Abrupt changes in hydraulic pressure can be prevented and the stability of the hydraulic circuit can be improved.

In addition, only by providing two through holes at predetermined locations of the valve body 13, the first port 15 can be prevented from closing the flow path between the first port 15 and the second port 16 by the valve body 13. , and the second port 16, it is possible to form an appropriate passage for circulating hydraulic oil, and easily obtain a valve device with optimum characteristics.

In addition, in the flow control valve according to the above-described embodiment, the hydraulic oil is erroneously circulated between the first port 15 of the casing 11 and the unused third port 17, In order not to affect the adjustment of the degree of communication between the port 15 and the second port 16, the first large diameter portion 13a of the valve body 13 is formed as a cylindrical region without grooves or recesses. is formed so that even if the valve body 13 moves, a flow path that communicates between the first port 15 and the third port 17 is not generated. Instead of preventing communication between the port 15 and the third port 17, a second outlet in the casing leading to the third port and the low pressure port of the directional valve as the return flow path of the hydraulic circuit. A closing member may be attached at a predetermined location between the second outlet and the second outlet to close the low pressure port.

In this case, regardless of the shape of the valve body, hydraulic fluid does not flow from the first port 15 to the third port leading to the closed second outlet. It is no longer necessary to strictly control the leakage of hydraulic oil to the return-side flow path through the fine gap between them.

10 flow control valve 11 casing 11a inlet portion 11b first outlet portion 11c second outlet portion 11d hole portion 11e first pressure receiving portion 11f second pressure receiving portion 11g secondary pressure passage 12, 13 valve body 12a first Large diameter portion 12b Second large diameter portion 12c Intermediate large diameter portion 12d First groove portion 12e Second groove portion 12f Tapered portion 12g First through hole 12h Second through hole 13a First large diameter portion 13b Second large diameter portion 13c groove portion 13d tapered portion 13g first through hole 13h second through hole 14 spring 15 first port 16 second port 17 third port 20 directional switching valve 21 spool 21c, 21d recess 23 pressure port 24, 25 Low pressure port 26, 27 Load side port 30 Pressure source 40 Low pressure part 50 Hydraulic motor 61, 62 Flow path 65 Counterbalance valve 91, 92 Valve device

Claims (5)

a casing having a fluid inlet, an outlet, and a hole communicating with the inlet and the outlet; A pressure-compensated flow control valve that adjusts the flow rate of fluid from an inlet to an outlet by moving a valve element based on a pressure difference in a circuit,
the outlet portion of the casing comprises a first outlet portion connected to the feed-side channel of the fluid pressure circuit and a second outlet portion connected to the return-side channel of the fluid pressure circuit,
The casing is
a first port that communicates the hole and the inlet;
a second port that is provided on the one moving direction side of the valve body in the hole with respect to the first port and that communicates the hole with the first outlet;
a third port provided on the other moving direction side of the valve body in the hole with respect to the first port and communicating the hole and the second outlet,
Further, the casing presses the valve disc in the one movement direction by applying the fluid pressure at a first predetermined location in the feed-side channel of the fluid pressure circuit communicating with the first outlet portion to the valve disc. and the fluid pressure at a second predetermined location separated by a predetermined throttle mechanism from the first predetermined location in the feed-side flow path is applied to the valve body in the other moving direction is formed as an appendable to press
The valve body
A groove or recess is provided to constantly communicate the first port and the second port, and the valve body moves in the one movement direction while enabling communication between the first port and the third port. Then, another groove or recess is provided that increases the degree of opening of communication between the first port and the third port, and decreases the degree of opening of communication between the first port and the third port when moving in the other direction of movement. Series circuit valve body, or
While allowing communication between the first port and the second port, moving in the one direction of movement reduces the degree of communication between the first port and the second port, and moving in the other direction of movement reduces the degree of communication between the first port and the second port. A parallel circuit valve body provided with a groove or recess that increases the opening of communication between the first port and the second port ,
one end of the valve body is applied with pressure to push the valve body in the one movement direction, and the other end of the valve body is applied with pressure to push the valve body in the other movement direction;
The valve body is adjacent to a predetermined groove or recess of the grooves or recesses that changes the degree of opening of communication between the first port and other ports as the valve body moves, having a predetermined large-diameter portion that is slidable in a passage portion between one port and another port;
At the end of the large-diameter portion facing the predetermined groove or recess, a curved tapered portion whose diameter tapers from the large-diameter portion in sliding contact with the casing toward the bottom surface of the predetermined groove or recess is formed. formed,
A first through hole is formed in at least the tapered portion of the valve body in a direction perpendicular to the longitudinal direction of the valve body,
A second through-hole that intersects and communicates with a part of the first through-hole is located closer to the other end of the valve than the first through-hole of the valve body, and is arranged in the longitudinal direction of the valve body A flow control valve characterized in that the valve body is perforated in a direction orthogonal to the In the flow control valve according to claim 1,
A flow regulating valve, wherein the parallel circuit valve element is formed by setting a predetermined region without grooves or recesses that keeps the first port and the third port in a non-communicating state at all times. In the flow control valve according to claim 1,
A flow regulating valve, wherein the casing is fitted with a closing member that closes the second outlet to a return-side flow path of a fluid pressure circuit to put it in a non-communicating state. In the flow control valve according to claim 1,
The valve body, which is the series circuit valve body, serves as the large-diameter portion between the one groove or recess and another groove or recess, and between the first port and the third port in the casing. has an intermediate large-diameter portion that can slidably contact the
When the valve body moves in the one movement direction, the intermediate large diameter portion moves away from the passage portion between the first port and the third port in the casing, increasing the opening of the communication between the first port and the third port. and moving in the other moving direction, the intermediate large-diameter portion approaches the passage portion between the first port and the third port in the casing, and the degree of opening of the communication between the first port and the third port is made smaller,
At the end of the intermediate large-diameter portion facing the other groove or recess, the curved tapered portion whose diameter tapers off from the large-diameter portion in sliding contact with the casing toward the bottom surface of the other groove or recess is formed. formed,
The first through hole is formed in at least the tapered portion of the valve body in a direction perpendicular to the longitudinal direction of the valve body,
The second through hole is formed in at least the intermediate large diameter portion of the valve body in a direction orthogonal to the longitudinal direction of the valve body and closer to the first groove or recess of the valve body than the first through hole. A flow control valve characterized by being In the flow control valve according to any one of claims 1 to 3,
The valve body, which is the parallel circuit valve body, has a large diameter portion as the large diameter portion, which is adjacent to the groove or the recess and is capable of slidably contacting the passage portion between the first port and the second port in the casing. having a diameter;
When the valve body moves in the one movement direction, the one large diameter portion approaches the passage portion between the first port and the second port in the casing, and the degree of opening of the communication between the first port and the second port. and moves in the other direction of movement, one large diameter portion is separated from the passage portion between the first port and the second port in the casing, and communication between the first port and the second port is designed to increase the opening of
At the end of one large-diameter portion facing the groove or recess, the curved tapered portion whose diameter tapers off from the large-diameter portion in sliding contact with the casing toward the bottom surface of the groove or recess is formed,
The first through hole is formed in at least the tapered portion of the valve body in a direction perpendicular to the longitudinal direction of the valve body,
Said second through-hole arranged in at least the bottom portion of said groove or recessed portion of said valve body in a direction perpendicular to the longitudinal direction of said valve body and further away from said one large-diameter portion of said valve body than said first through-hole. A flow regulating valve characterized in that a is drilled.

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