CN112503042A

CN112503042A - Pilot valve structure and proportional pressure reducing valve

Info

Publication number: CN112503042A
Application number: CN202010962432.6A
Authority: CN
Inventors: 张策; 虞拯; 翁之旦; 雷蕾; 陈飞飞
Original assignee: Ningbo Hoyea Machinery Manufacture Co Ltd
Current assignee: Ningbo Hoyea Machinery Manufacture Co Ltd
Priority date: 2020-09-14
Filing date: 2020-09-14
Publication date: 2021-03-16
Anticipated expiration: 2040-09-14
Also published as: CN112503042B

Abstract

The invention provides a pilot valve structure, belonging to the technical field of reducing valves, comprising: the pilot valve body is provided with a first valve hole and a first oil return channel, and the first valve hole comprises a first oil inlet cavity, a first working cavity and a first oil return cavity which are sequentially communicated; the pilot valve core is movably arranged in the first valve hole; a drive assembly provided on the pilot valve body; still provide a proportional pressure reducing valve, including the pilot valve structure, still include: the pressure reducing valve body is provided with a second valve hole, a second oil return channel, a left cavity and a right cavity; and the pressure reducing valve core is arranged in the second valve hole, and is provided with a blocking part, an oil inlet hole and a third radial hole. The invention has the beneficial effects that: the pilot valve has the advantages of ingenious structure, convenient control and high control precision; the pilot valve is arranged on the proportional pressure reducing valve, so that the proportional pressure reducing valve can be automatically controlled and has a good control effect.

Description

Pilot valve structure and proportional pressure reducing valve

Technical Field

The invention belongs to the technical field of pressure reducing valves, relates to a pilot valve structure, and further relates to a proportional pressure reducing valve with the pilot valve structure.

Background

The pressure reducing valve is a common pressure control element in a hydraulic system, is a pressure regulating valve and is commonly used for stabilizing the working pressure of an oil way.

For example, a chinese patent with application number CN108662222A discloses a pilot-operated three-way proportional pressure reducing valve, which includes a main valve body, an oil return port is provided in the main valve body, the pilot-operated three-way proportional pressure reducing valve further includes a pilot valve, and the pilot valve includes: a pilot valve body; a proportional electromagnet; a maximum pressure protection mechanism; and a flow stabilizing mechanism.

The pressure reducing valve actually comprises a pilot structure and an integral pressure reducing valve structure, although the pressure can be controlled by using the proportional electromagnet, the structure is complex, the control is troublesome, and the control precision is poor.

Disclosure of Invention

The invention aims to solve the problems in the prior art, and provides a pilot valve structure and a proportional pressure reducing valve.

The purpose of the invention can be realized by the following technical scheme: a pilot valve arrangement comprising:

the pilot valve body is provided with a first valve hole and a first oil return channel, the first valve hole comprises a first oil inlet cavity, a first working cavity and a first oil return cavity which are sequentially communicated, and the first oil return cavity is communicated with the first oil return channel;

the pilot valve core is movably arranged in the first valve hole, a first radial hole and a second radial hole are formed in the pilot valve core, an oil passing groove is formed in the peripheral surface of the end part of the pilot valve, the first radial hole is intersected and communicated with the second radial hole, the first radial hole is communicated with the first oil inlet cavity, and two ends of the oil passing groove are respectively communicated with the first working cavity and the first oil return cavity so as to enable the first working cavity and the first oil return cavity to be communicated;

and the driving assembly is arranged on the pilot valve body and can push the pilot valve core to move, so that the second radial hole is communicated with the first working cavity, and the oil passing groove is separated from the first working cavity.

Preferably, the pilot valve core is further provided with a third radial hole, a blind hole is formed in the end face of the pilot valve core, the third radial hole is communicated with the blind hole, the blind hole is communicated with the first working cavity through the third radial hole, and a hydraulic medium can enter the blind hole from the first working cavity and push the pilot valve core to move towards the driving assembly, so that the oil passing groove is communicated with the first working cavity.

Preferably, an installation cavity is formed in the pilot valve body, a sealing plug is arranged in the installation cavity, the sealing plug penetrates through the blind hole to seal the blind hole, and when a hydraulic medium enters the blind hole, the pilot valve core is pushed to move.

Preferably, a first spring is further disposed in the mounting cavity, and the first spring is in abutting connection with the sealing plug so as to apply an elastic force to the sealing plug, wherein the elastic force pushes the sealing plug towards the blind hole.

Preferably, two ends of the pilot valve core are respectively provided with a first return spring, and the two first return springs are used for applying elastic force for returning to the two ends of the pilot valve core.

Preferably, the driving assembly comprises a proportional electromagnet and a push rod, one end of the push rod is connected with the proportional electromagnet, and the other end of the push rod is connected with the pilot valve core.

Secondly, provide a proportional pressure reducing valve, including the pilot valve structure, still include:

the pressure reducing valve body is provided with a second valve hole, a second oil return channel, a left cavity and a right cavity, the second valve hole comprises a second oil inlet cavity, a second working cavity and a second oil return cavity which are sequentially communicated, the second working cavity is communicated with the second oil return cavity, the second oil return cavity is communicated with the second oil return channel, and the right cavity is communicated with the first working cavity;

and the pressure reducing valve core is arranged in the second valve hole, two ends of the pressure reducing valve core are respectively arranged in the left cavity and the right cavity, a plugging part, a communication hole and a fourth radial hole are arranged on the pressure reducing valve core, the communication hole is communicated with the left cavity, the fourth radial hole is arranged on the plugging part and is communicated with the communication hole, the fourth radial hole is communicated with the second working cavity, and the plugging part is positioned between the second oil inlet cavity and the second working cavity and enables the second oil inlet cavity and the second working cavity to be isolated.

Preferably, a first communicating groove and a second communicating groove are formed in the pressure reducing valve core, the second working cavity is communicated with the second oil return cavity through the first communicating groove, and when the pressure reducing valve core moves towards the left cavity direction, the second working cavity is communicated with the second oil inlet cavity through the second communicating groove.

Preferably, the left cavity and the right cavity are respectively located at two ends of the second valve hole.

Preferably, second return springs are arranged in the left cavity and the right cavity, and the two second return springs are respectively connected with two ends of the pressure reducing valve core in an abutting mode.

Compared with the prior art, the invention has the beneficial effects that:

1. the pressure of first working chamber needs to be equal to driving force in fact, that is to say, only need give a driving force, just can obtain the pressure of a fixed first working chamber, so can change the pressure that driving force changes first working chamber, the controlled pressure of first working chamber is in proportion relation with driving force, very convenience when control, only need give different driving force just can obtain the pressure of the first working chamber that corresponds, can adopt remote control's mode or change the mode control drive assembly of electric current size in actual structure, and then control the pressure of first working chamber, and control accuracy is high.

2. Through third radial hole and blind hole structure, can make first working chamber remove when pressure is greater than drive power for the hydraulic medium in the first working chamber flows away from first oil return chamber, has just so reduced the pressure in first working chamber, finally makes the pressure regulation in first working chamber equal as to drive power, and whole in-process control accuracy is high, only need give a drive power, and the pressure in first working chamber just can be adjusted automatically.

3. The sealing plug penetrates through the blind hole so as to seal the blind hole, and the sealing plug can move in the blind hole; when hydraulic medium enters the blind hole, the pilot valve core is pushed to move.

4. The pressure of a fixed second working cavity can be obtained only by giving a driving force, so that the pressure of the second working cavity can be changed by changing the driving force, namely, the controlled pressure of the second working cavity is in a proportional relation with the driving force, the control is very convenient, the pressure of the corresponding second working cavity can be obtained only by giving different driving forces, the driving assembly can be controlled in a remote control mode or a current size changing mode in an actual structure, the pressure of the second working cavity is further controlled, and the control precision is high.

5. The structure of the pressure reducing valve is very ingenious, the pressure reducing regulation of the second working cavity is realized through the pressure balance of the left cavity and the right cavity, the second working cavity can reach a large working flow, the pressure of the second working cavity can be relieved to zero when driving force is not applied, and the safety of a working mechanism is guaranteed.

Drawings

Fig. 1 is a schematic view of a pilot valve structure of the present invention.

FIG. 2 is a schematic diagram of the proportional pressure reducing valve of the present invention in an unactuated state.

Fig. 3 is a schematic structural diagram of the pilot valve cartridge of the present invention.

Fig. 4 is a schematic structural view of the oil passing groove of the present invention.

FIG. 5 is a side view of the pilot valve arrangement of the present invention.

Fig. 6 is a schematic view of the proportional pressure reducing valve of the present invention in a state of receiving a driving force.

Fig. 7 is a schematic view of the proportional pressure reducing valve of the present invention in a state of pressure holding.

In the figure, 100, a pilot valve body; 110. a first valve hole; 111. a first oil inlet chamber; 112. a first working chamber; 113. a first oil return cavity; 120. a first oil return passage; 130. a mounting cavity; 131. a first spring; 140. a sealing plug; 150. a first return spring; 200. a pilot valve spool; 210. a first radial bore; 220. a second radial bore; 230. a third radial hole; 240. blind holes; 250. an oil passing groove; 300. a drive assembly; 310. a proportional electromagnet; 320. a push rod; 400. a pressure reducing valve body; 410. a second valve hole; 411. a second oil inlet chamber; 412. a second working chamber; 413. a second oil return cavity; 420. a second oil return passage; 430. a left cavity; 440. a right cavity; 450. a second return spring; 500. a pressure reducing valve core; 510. a plugging section; 520. a communicating hole; 530. a fourth radial hole; 540. a first connecting groove; 550. and a second communicating groove.

Detailed Description

The following are specific embodiments of the present invention and are further described with reference to the drawings, but the present invention is not limited to these embodiments.

As shown in fig. 1, 2, 3, 4, 5, 6, and 7, a pilot valve structure includes: the pilot valve body 100, the pilot spool 200, and the drive unit 300 are configured to control the operation of the pilot spool 200 by the drive unit 300 and to control the pressure of the pressure reducing valve by the operation of the pilot spool 200.

The pilot valve body 100 is provided with a first valve hole 110 and a first oil return passage 120, and the first oil return passage 120 communicates with a tank, and can introduce a hydraulic medium into the tank.

The first valve hole 110 includes a first oil inlet chamber 111, a first working chamber 112 and a first oil return chamber 113 which are sequentially communicated, and preferably, the first valve hole 110 is shaped like a stepped hole structure, wherein a hydraulic medium with pressure can enter the first oil inlet chamber 111, and the first working chamber 112 is communicated with a component which needs to utilize the working medium; the first oil return chamber 113 communicates with the first oil return passage 120.

It is worth mentioning here that the first working chamber 112 is a relatively important chamber, and the pilot valve arrangement outputs pressure and working medium via the first working chamber 112.

The hydraulic medium in the first oil feed chamber 111 can enter the first working chamber 112, and the hydraulic medium in the first working chamber 112 can be discharged from the first oil return chamber 113 to perform a pressure reducing function.

The pilot valve core 200 is a shaft-shaped structure and is movably disposed in the first valve hole 110, where it should be noted that the pilot valve core 200 can seal the seal with the smallest inner diameter of the first valve hole 110, and in short, the pilot valve core 200 can seal the hole portion between the first oil inlet chamber 111 and the first working chamber 112 and the hole portion between the first working chamber 112 and the first oil return chamber 113.

When the driving force is not applied to the pilot valve spool 200, the pilot valve spool 200 blocks the first valve hole 110, so that the first oil inlet chamber 111 is isolated from the first working chamber 112, and after the driving force is applied, the first oil inlet chamber 111 communicates with the first working chamber 112, and the first working chamber 112 communicates with or is isolated from the first oil return chamber 113 according to the pressure.

The pilot valve core 200 is provided with a first radial hole 210 and a second radial hole 220, the circumferential surface of the end of the pilot valve is provided with an oil passing groove 250, and the oil passing groove 250 is actually a groove body structure formed along the axial direction.

The first radial hole 210 intersects and communicates with the second radial hole 220, and the first radial hole 210 communicates with the first oil inlet chamber 111, and preferably, when the pilot spool 200 moves so that the second radial hole 220 enters the first working chamber 112, the hydraulic medium (high pressure oil) enters the second radial hole 220 through the first radial hole 210 from the first oil inlet chamber 111, and can enter the first working chamber 112 from the second radial hole 220.

It should be noted here that the position of the second radial hole 220 can be changed when the pilot spool 200 moves, so as to change the communication area between the second radial hole 220 and the first working chamber 112, for example, the larger the distance the pilot spool 200 is pushed, the larger the communication area between the second radial hole 220 and the first working chamber 112.

Both ends of the oil passing groove 250 are respectively communicated with the first working chamber 112 and the first oil return chamber 113 so as to communicate the first working chamber 112 and the first oil return chamber 113; preferably, the first oil return chamber 113 and the first working chamber 112 may communicate through the oil groove 250, when no driving force is applied to the pilot spool 200, the first oil return chamber 113 and the first working chamber 112 communicate, so that the pressure in the first working chamber 112 is zero, this arrangement may allow the controlled pressure in the first working chamber 112 to be relieved to zero, when the pilot spool 200 receives the driving force, the first working chamber 112 is removed from the first working chamber 112 through the oil groove 250, at this time, the first working chamber 112 and the first oil return chamber 113 do not communicate, the hydraulic medium in the first working chamber 112 does not flow out from the first oil return chamber 113, and the pressure in the first working chamber 112 is maintained at the set pressure.

And a driving assembly 300 disposed on the pilot valve body 100, wherein the driving assembly 300 may push the pilot spool 200 to move, thereby communicating the second radial hole 220 with the first working chamber 112 and separating the oil passing groove 250 from the first working chamber 112.

Preferably, the driving assembly 300 may have a proportional electromagnet 310 structure, and may also have a linear motor or a cylinder structure, which only needs to be able to push the pilot poppet 200.

The principle of the pilot valve structure is as follows: high-pressure oil (hydraulic medium) is pumped into the first oil inlet cavity 111, when the driving assembly 300 does not apply driving force, that is, does not push the pilot valve core 200 to move, the second radial hole 220 does not enter the first working cavity 112, at this time, the high-pressure oil cannot enter the first working cavity 112, and the first working cavity 112 is communicated with the first oil return cavity 113 through the oil through groove 250 so as to be relieved to zero pressure.

When the driving assembly 300 pushes the pilot poppet 200 to move (to the right in the drawing), the second radial hole 220 enters the first working chamber 112, and gradually leaves the first working chamber 112 through the oil groove 250, at this time, high-pressure oil enters the second radial hole 220 from the first radial hole 210, and enters the first working chamber 112 from the second radial hole 220, the first working chamber 112 is not communicated with the first oil return chamber 113, and at this time, the high-pressure oil cannot enter the first oil return chamber 113, so that the high-pressure oil exists in the first working chamber 112 and pressure is built.

And when the pressure in the first working chamber 112 is higher than the set value, the pressure in the first working chamber 112 may move the pilot valve spool 200 toward the driving assembly 300, at this time, the pilot valve spool 200 moves leftward, so that the communication surface between the second radial hole 220 and the first working chamber 112 is reduced, and the oil groove 250 reenters the first working chamber 112, the high-pressure oil in the first working chamber 112 flows back into the oil tank through the first oil return chamber 113, at this time, the pressure in the first working chamber 112 is reduced, so that the driving force may push the pilot valve spool 200 to move rightward, then the communication surface between the second radial hole 220 and the first working chamber 112 is increased, and the oil groove 250 exits the first working chamber 112.

It should be noted that, for convenience of describing the operation process of the pilot valve structure, it is assumed that the driving force of the driving assembly 300 is F1, the pressure of the first working chamber 112 is F2, and the first working chamber 112 can establish the pushing force F3 through the corresponding structure, the pushing force F3 is equal to the pushing force F2, when F1 is greater than F2, the pilot valve element 200 moves to the right, and when the pilot valve element 200 moves to the right to a certain extent, the pushing force F2 increases, and at this time, the pilot valve element 200 moves to the left. When F2 is greater than F1, the pilot poppet 200 moves leftward, and when F2 decreases after the pilot poppet 200 moves leftward to some extent, the pilot poppet 200 moves rightward.

The operation of the pilot valve spool 200 is actually a dynamic adjustment process, and the final case is that F1 equals F2, because the pilot valve spool 200 must move to F1 equals F2 to stop moving, otherwise it will continuously move left and right until reaching equilibrium.

From the above movement process, it can be found that the pressure of the first working chamber 112 is actually required to be equal to or proportional to the driving force, that is, only one driving force needs to be given to obtain the pressure of a fixed first working chamber 112, so that the driving force can be changed to change the pressure of the first working chamber 112, that is, the controlled pressure of the first working chamber 112 is proportional to the driving force, and the pilot valve spool 200 is controlled by a smart structure, which is very convenient in control, and only different driving forces need to be given to obtain the corresponding pressure of the first working chamber 112, and in an actual structure, the driving assembly 300 can be controlled by adopting a remote control mode or a current magnitude changing mode to further control the pressure of the first working chamber 112, and the control precision is high.

As shown in fig. 1, 2, 3, 4, 5, and 6, based on the above embodiment, the pilot valve core 200 is further provided with a third radial hole 230, a blind hole 240 is formed on an end surface of the pilot valve core 200, the third radial hole 230 passes through the blind hole 240, the blind hole 240 is actually a hole-shaped structure formed at the right end of the pilot valve core 200, the blind hole 240 may form a cavity structure, and the pilot valve core 200 achieves the purpose of moving toward the driving assembly 300 through the blind hole 240 and the third radial hole 230.

The third radial hole 230 is communicated with the blind hole 240, and the blind hole 240 is communicated with the first working chamber 112 through the third radial hole 230, so that the hydraulic medium can enter from the first working chamber 112 into the blind hole 240 and push the pilot valve spool 200 to move towards the driving assembly 300, and the oil passing groove 250 is communicated with the first working chamber 112.

Preferably, the driving assembly 300 provides a driving force and pushes the pilot spool 200 to move rightward, at which time the oil groove 250 is removed from the first working chamber 112, so that the first working chamber 112 cannot be depressurized through the first oil returning chamber 113.

If the pressure cannot be relieved, the desired working pressure, i.e., the desired pressure of first working chamber 112, cannot be achieved after the driving force is given.

In a specific adjusting process, if pressure relief is needed, the pilot valve element 200 needs to be moved leftward, when the pressure in the first working chamber 112 is greater than a driving force, high-pressure oil enters the blind hole 240 from the third radial hole 230, a cavity is formed in the blind hole 240, the pressure F3 in the blind hole 240 is equal to the pressure F2 in the first working chamber 112, and F3 is greater than the driving force F1, so that the high-pressure oil pushes the pilot valve element 200 to move leftward, and at this time, the high-pressure oil reenters the first working chamber 112 through the oil groove 250, flows out of the first working chamber 112 through the first oil return cavity 113, so that the pressure in the first working chamber 112 is reduced, and the pressure in the first working chamber 112 is equal to the driving force after continuous dynamic adjustment.

Through the structure of the third radial hole 230 and the blind hole 240, the pilot spool 200 can move when the pressure in the first working chamber 112 is greater than or less than the driving force, so that the hydraulic medium in the first working chamber 112 flows away from the first oil return cavity 113, the pressure in the first working chamber 112 is reduced, and finally the pressure in the first working chamber 112 is adjusted to be equal to or proportional to the driving force.

As shown in fig. 1, 2, 6, and 7, in the above-described embodiment, the pilot valve body 100 is provided therein with the mounting cavity 130, and the mounting cavity 130 corresponds to an end portion of the pilot valve hole and can communicate with the end portion.

A sealing plug 140 is arranged in the mounting cavity 130, the sealing plug 140 is arranged in the blind hole 240 in a penetrating manner so as to seal the blind hole 240, and the sealing plug 140 can move in the blind hole 240; when the hydraulic medium enters the blind hole 240, the pilot valve spool 200 is pushed to move.

Preferably, the sealing plug 140 is plugged into the blind hole 240, so that a cavity structure is formed in the blind hole 240, and the sealing plug 140 and the pilot valve core 200 are not integrated, so that when the sealing plug 140 is inserted into the blind hole 240, pressure can be built in the blind hole 240, and the movement of the pilot valve core 200 is not influenced.

During actual operation, the pressure in the blind hole 240 is the same as the pressure in the first working chamber 112, and when the pressure in the first working chamber 112 is greater than the driving force, the hydraulic medium in the blind hole 240 pushes the pilot valve spool 200 to move leftward, specifically, the hydraulic medium pushes the pilot valve spool 200 leftward, and applies a rightward force to the sealing plug 140, so that the pilot valve spool 200 moves relative to the sealing plug 140, thereby driving the pilot valve spool 200 to move.

As shown in fig. 1, 2, 6 and 7, in addition to the above embodiment, a first spring 131 is further disposed in the mounting cavity 130, and the first spring 131 is in interference connection with the sealing plug 140 so as to apply an elastic force to the sealing plug 140 to push the sealing plug 140 toward the blind hole 240.

Preferably, the sealing plug 140 is threaded into the blind hole 240 by the first spring 131, that is, the first spring 131 provides the sealing plug 140 with a leftward elastic force, and the sealing plug 140 is not pressed out of the blind hole 240 due to the first spring 131 in any operating state.

As shown in fig. 1, 2, 6, and 7, in the above embodiment, the pilot valve body 200 is provided with first return springs 150 at both ends thereof, and the two first return springs 150 apply elastic force for returning to both ends of the pilot valve body 200.

Preferably, the first return springs 150 are capable of returning and centering the pilot valve spool 200, and specifically, when the driving force is removed, the pilot valve spool 200 needs to be returned or centered, and at this time, the two first return springs 150 respectively apply a return elastic force to the pilot valve spool 200, so that the pilot valve spool 200 moves to an initial position or a centered position, and at this time, the elastic forces generated by the two first return springs 150 are balanced, thereby ensuring the reliability of the pilot valve spool 200 after being returned.

As shown in fig. 1, 2, 6, and 7, in the above embodiment, the driving assembly 300 includes a proportional electromagnet 310 and a push rod 320, and one end of the push rod 320 is connected to the proportional electromagnet 310 and the other end is connected to the pilot valve spool 200.

Preferably, the proportional electromagnet 310 is an existing driving structure, and is capable of generating a corresponding electromagnetic force according to an input current, when the proportional electromagnet 310 is energized, the push rod 320 is ejected, and the push rod 320 applies a driving force to the pilot valve spool 200.

As shown in fig. 1, 2, 6, and 7, a proportional pressure reducing valve includes a pilot valve structure, and further includes: in the actual configuration of the pressure reducing valve body 400 and the pressure reducing valve body 500, the pilot valve body 100 is connected to the pressure reducing valve body 400, and the pilot valve structure can control the operating pressure of the proportional pressure reducing valve.

The pressure reducing valve body 400 is provided with a second valve hole 410, a second oil return passage 420, a left cavity 430 and a right cavity 440, the left cavity 430 and the right cavity 440 are respectively located at two ends of the second valve hole 410 and communicated with the second valve hole 410, the second valve hole 410 is similar to a stepped hole structure, and the second oil return passage 420 is communicated with an oil tank.

The second valve hole 410 includes a second oil inlet chamber 411, a second working chamber 412 and a second oil return chamber 413 which are sequentially communicated, preferably, the second oil inlet chamber 411 is connected with high pressure oil (hydraulic medium), that is, the high pressure oil with pressure is directly pumped into the second oil inlet chamber 411, the second working chamber 412 is connected with a working mechanism, such as a motor and other mechanisms, and the pressure of the second oil return chamber 413 communicated with an oil tank is always zero, wherein, because the pressure in the second oil inlet chamber 411 is higher and the required working pressure in the second working chamber 412 is lower, pressure reduction is required.

The second working chamber 412 is communicated with the second oil return chamber 413, and the second oil return chamber 413 is communicated with the second oil return passage 420, so that the second working chamber 412 is directly communicated with an oil tank, the pressure of the second working chamber 412 can be relieved to zero pressure, at the moment, the second working chamber 412 is safer, and when the second working chamber 412 is not in operation, the second working chamber 412 is isolated from the second oil inlet chamber 411, so that high-pressure oil cannot enter the second working chamber 412 from the second oil inlet chamber 411.

The right chamber body 440 is in communication with the first working chamber 112; preferably, the right chamber 440 is in communication with the first working chamber 112, so that the pressure of the right chamber 440 is equal to the pressure of the first working chamber 112, i.e., the driving force is proportional to the pressure of the right chamber 440.

The pressure reducing valve spool 500 is disposed in the second valve hole 410, and the pressure reducing valve spool 500 is movable in the second valve hole 410; two ends of the pressure reducing valve core 500 are respectively arranged in the left cavity 430 and the right cavity 440, so that the left cavity 430 and the right cavity 440 can push the pressure reducing valve core 500 to move, wherein pressure can be built after high-pressure oil is introduced into the right cavity 440, the pressure reducing valve core 500 is pushed to move leftwards, and if the pressure of the left cavity 430 is greater than that of the right cavity 440, the left cavity 430 can push the pressure reducing valve core 500 to move rightwards.

It should be noted that the first working chamber 112 is communicated with the right chamber 440, so that the high-pressure oil in the first working chamber 112 can flow into the right chamber 440 through the connecting passage, at this time, the right chamber 440 has pressure, the left chamber 430 is actually communicated with the second return oil chamber 413, the pressure of the left chamber 430 is zero, and the right chamber 440 can push the pressure reducing valve spool 500 to move leftward.

The pressure reducing valve body 500 is provided with a blocking portion 510, a communication hole 520, and a fourth radial hole 530, and preferably, the pressure reducing valve body 500 is provided with two annular grooves, the blocking portion 510 is formed between the two annular grooves, the blocking portion 510 can block the portion with the smallest inner diameter of the second valve hole 410, the communication hole 520 is a hole body structure provided along the axial direction of the pressure reducing valve body 500, and the fourth radial hole 530 is communicated with the communication hole 520.

The communication hole 520 is communicated with the left cavity 430, and the opening of the communication hole 520 is communicated with the left cavity 430; the fourth radial hole 530 is provided in the blocking portion 510 to communicate with the communication hole 520, the fourth radial hole 530 communicates with the second working chamber 412 so that the left chamber body 430 communicates with the second working chamber 412, and the blocking portion 510 is located between and separates the second oil inlet chamber 411 and the second working chamber 412.

Since the blocking portion 510 blocks the space between the second working chamber 412 and the second oil inlet chamber 411, the second working chamber 412 is communicated with the second oil return chamber 413, and the left chamber 430 is communicated with the second working chamber 412 through the communication hole 520 and the fourth radial hole 530, the left chamber 430 is communicated with the second oil return chamber 413, that is, the pressure of the left chamber 430 is zero, and the pressure of the left chamber 430 can be established when the second working chamber 412 is not communicated with the second oil return chamber 413.

In a specific pressure reduction process, when the driving assembly 300 does not apply a driving force to the pilot valve core 200, the pressure of the first working chamber 112 is zero at this time, so the pressure of the right chamber 440 is also zero, and the second working chamber 412 is communicated with the second oil return chamber 413, so that the pressure of the second working chamber 412 is relieved to zero, and the pressure of the left chamber 430 is also zero.

When the driving assembly 300 applies a driving force to the pilot valve spool 200, the pressure of the first working chamber 112 is controllable, that is, the magnitude of the driving force determines the pressure of the first working chamber 112, the pressure of the first working chamber 112 determines the pressure of the right chamber 440, and after the high-pressure oil enters the right chamber 440, the right chamber 440 can push the pressure reducing valve spool 500 to move leftward.

When the pressure reducing valve body 500 moves leftward, the blocking portion 510 moves between the second working chamber 412 and the second oil return chamber 413, so that the high-pressure oil in the second oil inlet chamber 411 enters the second working chamber 412, and the high-pressure oil in the second working chamber 412 does not flow out of the second oil return chamber 413.

When the second working chamber 412 communicates with the second oil inlet chamber 411, since the left chamber body 430 always communicates with the second working chamber 412 through the communication hole 520 and the fourth radial hole 530, the pressure of the left chamber body 430 is equal to the pressure of the second working chamber 412, and if the pressure of the left chamber body 430 is greater than the pressure of the right chamber body 440, the pressure reducing spool 500 is moved rightward.

When the pressure reducing valve spool 500 moves rightward, the blocking portion 510 moves away from the second working chamber 412 and the second return chamber 413, so that the high-pressure oil in the second working chamber 412 can flow away from the second return chamber 413, and thus a pressure relief effect is achieved, at this time, the pressure in the second working chamber 412 is reduced, so that the pressure in the left chamber 430 is reduced, and if the pressure in the left chamber 430 is lower than the pressure in the right chamber 440, the pressure reducing valve spool 500 moves leftward again.

As can be seen from the above description, the movement of the pressure reduction spool 500 is a dynamic process in nature, and once the pressures of the left and

right chambers

430 and 440 are not equal, the pressure reduction spool 500 moves until the pressures of the left and

right chambers

430 and 440 are equal, and specifically, the pressure of the right chamber 440 is equal to or proportional to the pressure of the first working chamber 112, i.e., the pressure of the right chamber 440 is equal to the pressure F2 of the first working chamber 112.

It is important to point out here that the pressure reducing valve core 500 finally moves to the equilibrium position because the pressure reducing valve core 500 moves due to the fact that the pressure of the left cavity 430 is greater than the pressure of the right cavity 440 or the pressure of the right cavity 440 is greater than the pressure of the left cavity 430, when the pressure reducing valve core 500 moves to the left, the pressure of the second working cavity 412 increases, the pressure of the left cavity 430 increases, then the pressure reducing valve core 500 moves to the right, the second working cavity 412 is communicated with the second return oil cavity 413, the pressure of the left cavity 430 decreases, and then the pressure reducing valve core 500 moves to the left until the pressures of the left cavity 430 and the right cavity 440 are equal, that is, the pressure reducing valve core 500 finally moves to the equilibrium position.

As can be seen from the above conclusion, the pressure reducing valve spool 500 is balanced, and the pressure of the left chamber 430 is F2, i.e. the pressure of the left chamber 430 is equal to or proportional to the pressure of the first working chamber 112, and the pressure of the second working chamber 412 is equal to or proportional to the pressure of the left chamber 430, i.e. the pressure of the second working chamber 412 is equal to or proportional to the pressure of the first working chamber 112, and the pressure of the first working chamber 112 determines the pressure of the second working chamber 412, so the driving force determines the pressure of the second working chamber 412.

That is to say, only one driving force needs to be given to obtain the pressure of the fixed second working chamber 412, so that the driving force can be changed to change the pressure of the second working chamber 412, that is, the controlled pressure of the second working chamber 412 is in a proportional relation with the driving force, the control is very convenient, only different driving forces need to be given to obtain the corresponding pressure of the second working chamber 412, the driving assembly 300 can be controlled in an actual structure in a remote control mode or a current magnitude changing mode, the pressure of the second working chamber 412 is further controlled, and the control precision is high.

Moreover, the structure of the pressure reducing valve is very ingenious, pressure reduction regulation of the second working chamber 412 is realized through pressure balance of the left cavity 430 and the right cavity 440, so that the second working chamber 412 can achieve a large working flow, pressure of the second working chamber 412 can be relieved to zero when no driving force is applied, and safety of a working mechanism is guaranteed.

In addition, during the pressure maintaining process of the pressure reducing valve, the high-pressure oil is lost in the pressure reducing valve, so that the pressure in the second working chamber 412 slightly fluctuates, at this time, the blocking part 510 is just positioned in the second working chamber 412, and the pressure in the second working chamber 412 is ensured to be stable according to the left and right micro movement of the actual pressure.

As shown in fig. 1, 2, 6, and 7, in the above embodiment, the pressure reducing valve body 500 is provided with a first communicating groove 540 and a second communicating groove 550, the second working chamber 412 communicates with the second oil return chamber 413 through the first communicating groove 540, and the second working chamber 412 communicates with the second oil inlet chamber 411 through the second communicating groove 550 when the pressure reducing valve body 500 moves in the direction of the left chamber 430.

Preferably, the first communicating groove 540 and the second communicating groove 550 of the pressure reducing valve core 500 are actually two annular grooves, the blocking portion 510 is located between the first communicating groove 540 and the second communicating groove 550, the first communicating groove 540 can communicate the second working chamber 412 with the second oil return chamber 413 when driving force is not applied, the second communicating groove 550 can communicate the second working chamber 412 with the second oil inlet chamber 411 when driving force is applied, and therefore it is ensured that the whole pressure reducing valve can normally work, and the pressure reducing valve has the advantage of large working flow.

As shown in fig. 1, 2, 6 and 7, in the above embodiment, the left cavity 430 and the right cavity 440 are respectively located at two ends of the second valve hole 410.

Preferably, the left and

right cavities

430 and 440 are communicated with both ends of the second valve hole 410, so that the pressure reducing valve core 500 can enter the left and

right cavities

430 and 440, and the movement of the pressure reducing valve core 500 is facilitated.

As shown in fig. 1, 2, 6, and 7, on the basis of the above embodiment, second return springs 450 are respectively disposed in the left cavity 430 and the right cavity 440, and the two second return springs 450 are respectively connected to two ends of the pressure reducing valve core 500 in an abutting manner.

Preferably, the second return springs 450 can return and center the pressure reducing valve core 500, and specifically, when the driving force is removed or not applied, the pressure reducing valve core 500 needs to be returned or centered, at this time, the two second return springs 450 respectively apply return elastic forces to two ends of the pressure reducing valve core 500, so that the pressure reducing valve core 500 moves to the initial position or the centered position, and at this time, the elastic forces generated by the two second return springs 450 are balanced, thereby ensuring the reliability of the pressure reducing valve core 500 after being returned.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications or additions may be made to the described embodiments or alternatives may be employed by those skilled in the art without departing from the spirit or ambit of the invention as defined in the appended claims.

Claims

1. A pilot valve arrangement, comprising:

2. A pilot valve arrangement as claimed in claim 1, wherein: the pilot valve core is also provided with a third radial hole, a blind hole is formed in the end face of the pilot valve core and communicated with the blind hole, the blind hole is communicated with the first working cavity through the third radial hole, a hydraulic medium can enter the blind hole from the first working cavity and push the pilot valve core to move towards the driving assembly, and therefore the oil passing groove is communicated with the first working cavity.

3. A pilot valve arrangement as claimed in claim 2, wherein: the pilot valve is characterized in that an installation cavity is formed in the pilot valve body, a sealing plug is arranged in the installation cavity and penetrates through the blind hole to seal the blind hole, and when a hydraulic medium enters the blind hole, the pilot valve core is pushed to move.

4. A pilot valve arrangement as claimed in claim 3, wherein: and a first spring is also arranged in the mounting cavity and is in abutting connection with the sealing plug so as to apply elastic force pushing the sealing plug to the blind hole.

5. A pilot valve arrangement as claimed in claim 4, wherein: and two first return springs are arranged at two ends of the pilot valve core and used for applying elastic force for resetting to two ends of the pilot valve core.

6. A pilot valve arrangement as claimed in claim 4, wherein: the driving assembly comprises a proportional electromagnet and a push rod, one end of the push rod is connected with the proportional electromagnet, and the other end of the push rod is connected with the pilot valve core.

7. A proportional pressure reducing valve including a pilot valve arrangement as claimed in any one of claims 3 to 6, further comprising:

8. The proportional pressure reducing valve as set forth in claim 7, wherein: the pressure reducing valve core is provided with a first communicating groove and a second communicating groove, the second working cavity is communicated with the second oil return cavity through the first communicating groove, and when the pressure reducing valve core moves towards the left cavity direction, the second working cavity is communicated with the second oil inlet cavity through the second communicating groove.

9. The proportional pressure reducing valve as set forth in claim 7, wherein: the left cavity and the right cavity are respectively positioned at two ends of the second valve hole.

10. The proportional pressure reducing valve of claim 9, wherein: and second reset springs are arranged in the left cavity and the right cavity and are respectively connected with two ends of the pressure reducing valve core in an abutting mode.