WO2021121170A1

WO2021121170A1 - Electro-hydraulic control valve for hydraulic operating mechanism, and electromagnetic pilot valve and pilot valve thereof

Info

Publication number: WO2021121170A1
Application number: PCT/CN2020/135954
Authority: WO
Inventors: 顾根泉; 张全民; 张朝辉; 王丽丽; 李文华; 王晗
Original assignee: 河南平高电气股份有限公司; 平高集团有限公司; 国家电网有限公司
Priority date: 2019-12-16
Filing date: 2020-12-11
Publication date: 2021-06-24
Also published as: CN111173800B; CN111173800A

Abstract

An electro-hydraulic control valve for a hydraulic operating mechanism, and an electromagnetic pilot valve (600/700/800/900) and a pilot valve thereof. The pilot valve comprises: a valve body (607); a valve sleeve, one end of which is provided with a valve port; a valve ball (611); a ball holder, elastically abutting against the valve ball (611) so that the valve ball (611) blocks the valve port; an oil inlet passage (616); an oil discharge passage (617); a valve rod (609) mounted in the valve sleeve in a guiding and moving manner, and moving under an external force to push the valve ball (611) so that the oil inlet passage (616) is in communication with the oil discharge passage (617) through an inner hole of the valve sleeve, the valve rod (609) comprising a large diameter segment (6092) in the middle and a first small diameter segment (6093) and a second small diameter segment (6091) at two sides, the first small diameter segment (6093) being used for pushing the valve ball (611), the second small diameter segment (6091) being used for receiving the external force, and forming a second annular cavity (618) with the valve sleeve; and a bypass oil passage (615), one end of which is in communication with the oil inlet passage (616), and the other end of which is in communication with the second annular cavity (618). The bypass oil passage (615) enables a part of the oil liquid to enter the second annular cavity (618) to act on the large diameter segment (6092), so as to apply a pre-pushing force to the valve rod (609) to move towards the direction of the valve ball (611), reducing an external force value actually required when the valve rod (609) really acts, enabling the valve rod (609) to act more easily, and have a faster acting speed.

Description

Electro-hydraulic control valve for hydraulic operating mechanism and its electromagnetic pilot valve and pilot valve

Cross-references to related applications

This application is filed based on the Chinese patent application with the application number 201911324257.1 and the filing date on December 16, 2019, and claims the priority of the Chinese patent application. The entire content of the Chinese patent application is hereby incorporated into this application by reference.

Technical field

The invention relates to an electro-hydraulic control valve for a hydraulic operating mechanism and its electromagnetic pilot valve and pilot valve.

Background technique

The electro-hydraulic control valve is the core control element in the hydraulic operating mechanism of the circuit breaker. When receiving the opening and closing commands, the electro-hydraulic control valve uses the opening and closing electromagnets and the opening and closing pilot valves to control the opening and closing of the control room. , The closing electrical signal is converted into a hydraulic signal, and then the hydraulic signal is amplified by the two-stage valve and the three-stage valve, and the corresponding position conversion is made, and the hydraulic cylinder is controlled to open or close, and the hydraulic cylinder operates the circuit breaker. Opening or closing action.

The action time and flow rate of the electro-hydraulic control valve directly affect the opening and closing time and the opening and closing speed of the circuit breaker. For ultra-high voltage circuit breakers, due to their high working voltage and large breaking current, the circuit breakers are required to have high opening speed, short action time, and large instantaneous operating power output by the operating mechanism. Therefore, ultra-high voltage circuit breakers are often required to be equipped. Hydraulic operating mechanism. The hydraulic operating mechanism is generally an instantaneous, constant high-pressure holding operating mechanism. In order to increase the operating power and increase the opening speed, the hydraulic system has a higher working pressure and requires a larger flow rate to ensure the required opening of the circuit breaker. Speed and action time, the electro-hydraulic control valve in the hydraulic operating mechanism often adopts multi-stage hydraulic valve step-by-step amplification to control the action of the large-diameter hydraulic cylinder, and the hydraulic cylinder drives the arc extinguishing chamber of the circuit breaker to open. Therefore, the action speed of the hydraulic cylinder, the amplification stages of the control valve, and the action time affect each other, and there is a better fit value in the structure.

The commonly used large flow control valve adopts a three-stage valve structure. For example, a hydraulic operating mechanism and its hydraulic control valve disclosed in a Chinese invention patent application with an application publication number of CN109764152A. The hydraulic control valve includes a valve seat and a valve assembly. The valve sleeve in the seat is equipped with a valve core in the valve sleeve. The valve seat includes a cylinder part and two end covers. The cylinder part is provided with a low-pressure oil chamber for communicating with the low-pressure oil tank, a hydraulic cylinder oil chamber for communicating with the hydraulic cylinder, and high-pressure oil for communicating with the high-pressure hydraulic system. Cavity. The outer circumference of the cylinder part is provided with a first-level gate valve and a first-level closing valve. In the cylinder wall of the cylinder part, a second-level gate valve is installed at a position corresponding to the first-level gate valve, and a second-level gate valve is installed at a position corresponding to the first-level gate valve. There is a two-stage closing valve. The primary gate valve controls the opening and closing of the secondary gate valve, the primary gate valve controls the opening and closing of the secondary gate valve, the primary gate valve and the primary gate valve are both pilot valves, the secondary gate valve and the secondary gate valve All are magnifying valves.

When the hydraulic operating mechanism is in the closing position for opening action, the first-stage opening valve and the second-stage opening valve are opened in sequence, and the spool moves, so that the low-pressure oil chamber communicates with the hydraulic cylinder oil chamber, and the high-pressure oil in the hydraulic cylinder oil chamber Drain into the low-pressure oil tank through the low-pressure oil chamber for opening action. When the hydraulic operating mechanism is in the opening position for closing action, the first-stage closing valve and the second-stage closing valve are opened in sequence, and the spool moves to make the hydraulic cylinder oil chamber communicate with the high-pressure oil chamber, and the high-pressure oil in the high-pressure oil chamber enters The hydraulic cylinder oil chamber performs closing action.

The above-mentioned hydraulic control valve adopts the structure of a three-stage valve. The first-stage gate valve and the first-stage closing valve are usually solenoid pilot valves driven by electromagnets. Both the second-stage gate valve and the second-stage closing valve are enlarged valves, with valve seats and valves. The sleeve and the spool constitute the main valve. The action time of the hydraulic control valve mainly depends on several components. One is the action time of the electromagnet and the pilot valve and the diameter and flow of the pilot valve. The second is the action time and amplification of the amplifier valve. The diameter and flow of the valve, the third is the action time of the main valve. The action time of the main valve depends on the diameter and flow of the amplifier valve, and the action time of the amplifier valve depends on the diameter and flow of the pilot valve.

Although the existing hydraulic control valve with this three-stage valve structure can control the action of a large-diameter hydraulic cylinder, and has a large flow rate and a fast action time, the three-stage valve has a relatively complicated structure, large dimensions, a large number of parts, and leakage. There are many oil links and high production costs. The reason why it is limited to the three-stage valve structure with step-by-step amplification is firstly because the pilot valve has a relatively small diameter and flow rate, and the valve stem of the pilot valve has a long action time, which cannot meet the requirements of fast action.

Summary of the invention

The purpose of the embodiments of the present invention is to provide a pilot valve that can act quickly; the purpose of the embodiments of the present invention is also to provide an electromagnetic pilot valve with a short action time; the purpose of the embodiments of the present invention is also to provide a simple structure, Electro-hydraulic control valve for hydraulic operating mechanism with short action time.

In order to achieve the foregoing objectives, the pilot valve in the embodiment of the present invention adopts the following technical solutions:

A pilot valve including:

Valve body

The valve sleeve is fixed in the valve body, the valve sleeve has an inner hole, and one end of the inner hole is the valve port;

The valve ball cavity is arranged in the valve body and located on one side of the valve port, and a valve ball is arranged in the valve ball cavity;

The ball holder is installed on the valve body and is used to elastically press-fit the valve ball so that the valve ball can block the valve port;

The oil inlet channel is arranged on the valve body, and the oil inlet channel is in communication with the valve ball cavity;

The oil drain channel is arranged on the valve body, and the oil drain channel is in communication with the inner hole of the valve sleeve;

The valve stem is installed in the valve sleeve for guiding movement. The valve stem is used to move in the valve sleeve by external force and push the valve ball, so that the oil inlet channel is connected with the oil discharge channel through the inner hole of the valve sleeve;

Among them, the valve stem includes a large diameter section in the middle and a first small diameter section and a second small diameter section located on both sides of the large diameter section. The large diameter section is in sliding fit with the valve sleeve. The first small diameter section is used to push the valve ball. A first annular cavity is formed between the small diameter section and the valve sleeve. The first annular cavity communicates with the oil discharge channel through a first communication structure provided on the valve sleeve. The second small diameter section is used to receive external forces. A second annular cavity is formed between the valve sleeves;

The pilot valve also includes:

The bypass oil passage is arranged in the valve body. One end of the bypass oil passage is connected with the oil inlet passage or the valve ball cavity, and the other end is connected with the second annular cavity, so that a part of the oil in the oil inlet passage or the valve ball cavity can be It enters the second annular cavity through the bypass oil passage, and applies a pre-thrust to the valve stem moving toward the valve ball; the valve sleeve is provided with a second communication structure for communicating the bypass oil passage with the second annular cavity.

The beneficial effect of the above technical solution is: because the valve ball is pressed by the elastic top pressure of the ball holder, the valve opening on the valve sleeve is normally blocked to block the oil inlet channel and the oil discharge channel. At this time, the pilot valve is in a closed state. And when in use, the oil enters the valve ball cavity through the oil inlet channel, and the pressure on the valve ball makes the valve ball tightly plugged on the valve port, keeping the pilot valve in the closed state; and when the valve stem is subjected to external force , Will move in the valve sleeve and overcome the reaction force of the ball holder and the oil pressure to push the valve ball open, so that the oil inlet channel is connected to the oil discharge channel through the inner hole of the valve sleeve, and the pilot valve is in an open state.

Since the valve stem includes a large-diameter section, a first small-diameter section, and a second small-diameter section, it forms a first ring cavity and a second ring cavity with the valve sleeve, and a bypass oil passage is also provided in the valve body, and one end of the bypass oil passage is connected with the valve sleeve. The oil inlet passage or valve ball cavity is connected, and the other end is connected with the second annular cavity, so that part of the oil in the oil inlet passage or valve ball cavity can enter the second annular cavity through the bypass oil passage and act on the large diameter section In this way, a pre-thrust force is applied to the valve stem to move toward the valve ball, that is, a part of the force is applied to the valve stem in advance, so that the actual external force required to make the valve stem actually moves can be reduced.

In other words, if the applied external force does not change, the valve stem of the pilot valve in the embodiment of the present invention is easier to move, the movement speed will be faster, and the valve ball will be easier to open. With this support, you can Increase the diameter of the pilot valve, and then increase the flow, so that the diameter and flow of the pilot valve can meet the action time of the main valve, thereby directly driving the main valve to move, eliminating the need for the amplification valve in the prior art, so that the Simplify the structure of the control valve under the premise of ensuring the use requirements.

In one embodiment, in order to facilitate manufacturing and assembly, the valve sleeve includes a first valve sleeve and a second valve sleeve arranged at intervals, the valve port is located on the first valve sleeve, and the large diameter section of the valve stem is guided by the second valve sleeve. Sliding fit, the first annular cavity is enclosed by the first small diameter section and the first valve sleeve, the second annular cavity is enclosed by the second small diameter section and the second valve sleeve, the interval between the first valve sleeve and the second valve sleeve The first communication structure is constituted, and the second communication structure is arranged on the second valve sleeve.

In an embodiment, in order to facilitate the communication between the bypass oil passage and the second annular cavity, the second communication structure includes a ring groove provided on the outer peripheral surface of the valve sleeve and a plurality of communication holes spaced at the bottom of the ring groove.

In one embodiment, in order to facilitate the oil discharge, the first small-diameter section and the large-diameter section are transitioned by a tapered surface, and the tapered surface corresponds to the position where the first communication structure is located.

In an embodiment, in order to facilitate processing and at the same time facilitate the oil to enter the second annular cavity, the bypass oil passage is composed of two intersecting oil passages, and the two intersecting oil passages are in the shape of "in".

In order to achieve the foregoing objectives, the electromagnetic pilot valve in the embodiment of the present invention adopts the following technical solutions:

An electromagnetic pilot valve includes an electromagnet. The electromagnet includes an electromagnet casing and a moving iron core arranged in the electromagnet casing. The moving iron core is used to provide an external force. The electromagnetic pilot valve further includes fixing to the electromagnet casing The connected pilot valve, the pilot valve includes:

Valve body

The valve stem is installed in the valve sleeve for guiding movement. The valve stem is used to move in the valve sleeve by the force of the moving iron core and push the valve ball, so that the oil inlet channel is connected with the oil discharge channel through the inner hole of the valve sleeve;

Among them, the valve stem includes a large diameter section in the middle and a first small diameter section and a second small diameter section located on both sides of the large diameter section. The large diameter section is in sliding fit with the valve sleeve. The first small diameter section is used to push the valve ball. A first annular cavity is formed between the small diameter section and the valve sleeve. The first annular cavity communicates with the oil discharge channel through a first communication structure provided on the valve sleeve. The second small diameter section is used to receive the force of the moving iron core. A second annular cavity is formed between the small diameter section and the valve sleeve;

The pilot valve also includes:

The beneficial effect of the above technical solution is: because the valve ball is pressed by the elastic top pressure of the ball holder, the valve opening on the valve sleeve is normally blocked to block the oil inlet channel and the oil discharge channel. At this time, the pilot valve is in a closed state. And when in use, the oil enters the valve ball cavity through the oil inlet channel, and the pressure on the valve ball makes the valve ball tightly plugged on the valve port, keeping the pilot valve in the closed state; and when the valve stem is affected by the moving iron core When the force is applied, it will move in the valve sleeve and overcome the reaction force of the ball holder and the oil pressure to open the valve ball, so that the oil inlet passage is connected to the oil discharge passage through the inner hole of the valve sleeve. At this time, the pilot valve is in an open state.

In one embodiment, in order to drive the valve stem more labor-saving, the electromagnetic pilot valve further includes a lever housing, the lever housing is located between the electromagnet housing and the valve body of the pilot valve, and the lever housing is connected to the electromagnet housing and the valve body respectively. The valve body of the pilot valve is fixedly connected. A lever is arranged in the lever housing. One end of the lever is rotatably assembled on the lever housing, and the other end is push-fitted with the moving iron core of the electromagnet. The lever also has a push-push with the valve stem of the pilot valve. The mating part can push the valve stem to move when the movable iron core pushes the lever to rotate.

In one embodiment, in order to reduce the overall height of the solenoid pilot valve and facilitate assembly and arrangement, the lever is L-shaped, and the axial direction of the movable iron core is perpendicular to the axial direction of the valve stem.

In order to achieve the above objective, the electro-hydraulic control valve for the hydraulic operating mechanism in the embodiment of the present invention adopts the following technical solutions:

An electro-hydraulic control valve for a hydraulic operating mechanism includes a main valve and an electromagnetic pilot valve connected to the main valve. The electromagnetic pilot valve includes an electromagnet. The electromagnet includes an electromagnet housing and a moving iron core arranged in the electromagnet housing , The moving iron core is used to provide external force, the electromagnetic pilot valve also includes a pilot valve fixedly connected with the electromagnet housing, the pilot valve includes:

Valve body

The pilot valve also includes:

Description of the drawings

Fig. 1 is a schematic structural diagram of an electro-hydraulic control valve for a hydraulic operating mechanism in an embodiment of the present invention;

Fig. 2 is a schematic diagram of the structure of the electromagnetic pilot valve in Fig. 1;

Figure 3 is a cross-sectional view along the line A-A in Figure 2;

Figure 4 is a partial structure diagram in Figure 3;

Figure 5 is a structural diagram of the valve seat in Figure 1;

Figure 6 is a working principle diagram of an electro-hydraulic control valve for a hydraulic operating mechanism in an embodiment of the present invention (opening state);

Fig. 7 is a working principle diagram (closed state) of the electro-hydraulic control valve for the hydraulic operating mechanism in the embodiment of the present invention.

In the figure: 100-valve seat; 101-first oil passage; 102-second oil passage; 103-third oil passage; 104-fourth oil passage; 105-fifth oil passage; 106-sixth oil passage; 107-seventh oil passage; 108-eighth oil passage; 109-ninth oil passage; 110-low pressure oil chamber; 111-hydraulic cylinder oil chamber; 112-high pressure oil chamber; 113-annulus; 114-center hole; 200-low pressure chamber valve sleeve; 201-first through hole; 300-high pressure chamber valve sleeve; 301-second through hole; 400-end cover; 500-spool; 600-first opening solenoid pilot valve; 601- Electromagnet housing; 602-moving iron core; 603-coil; 604-lever; 605-ball holder; 606-end plate; 607-valve body; 608-second valve sleeve; 609-valve stem; Two small-diameter sections; 6092-large-diameter section; 6093-first small-diameter section; 6094-cone surface; 610-first valve sleeve; 611-valve ball; 612-top block; 613-spring; 614-communication hole; 615- Bypass oil passage; 616-oil inlet passage; 617-oil drain passage; 618-second ring cavity; 619-static iron core; 620-first ring cavity; 621-ring groove; 622-interval; 623-lever housing Body; 700-Second opening electromagnetic pilot valve; 800-First closing electromagnetic pilot valve; 900-Second closing electromagnetic pilot valve.

Detailed ways

An example of the electro-hydraulic control valve for the hydraulic operating mechanism in the embodiment of the present invention is shown in Figure 1. The electro-hydraulic control valve for the hydraulic operating mechanism (hereinafter referred to as the electro-hydraulic control valve) includes a main valve and a valve mounted on the main valve. Four solenoid pilot valves. The four solenoid pilot valves are the first opening solenoid pilot valve 600, the second opening solenoid pilot valve 700, the first closing solenoid pilot valve 800, and the second closing solenoid pilot valve 900. The structure of the solenoid pilot valve is the same.

Taking the first opening electromagnetic pilot valve 600 as an example, as shown in FIG. 2, it includes an electromagnet and a pilot valve. The electromagnet includes an electromagnet housing 601, and the electromagnet housing 601 is provided with a movable iron core 602 and a static The iron core 619 and the coil 603, when the electromagnet is energized, the moving iron core 602 outputs a direct motion action. The working principle of the electromagnet is the same as that of the prior art, and will not be repeated here.

As shown in Figure 3 and Figure 4, the pilot valve includes a valve body 607 with a valve sleeve fixed in the valve body 607. The valve sleeve in this embodiment includes a first valve sleeve 610 and a second valve sleeve 608 arranged at intervals. There is an interval 622 between the valve sleeve 610 and the second valve sleeve 608. Both valve sleeves have inner holes, and one end of the inner hole of the first valve sleeve 610 away from the second valve sleeve 608 is a valve port.

A valve ball cavity is provided in the valve body 607, the valve ball cavity is located on one side of the valve port, and a valve ball 611 is provided in the valve ball cavity. A ball holder is installed on the valve body 607. The ball holder includes a ball holder 605 threadedly connected to the valve body 607, a top block 612 and a spring 613 arranged in the ball holder 605. The top block 612 is connected to the valve under the action of the spring 613. The ball 611 is elastically press-fitted to make the valve ball 611 block the valve port.

A valve stem 609 is guided and slidingly installed in the valve sleeve. The valve stem 609 includes a large diameter section 6092 in the middle and a first small diameter section 6093 and a second small diameter section 6091 located on both sides of the large diameter section. The large diameter section 6092 and the second valve sleeve 608 Guide sliding fit, the first small diameter section 6093 is used to push the valve ball 611, and a first annular cavity 620 is formed between the first small diameter section 6093 and the first valve sleeve 610. The second small diameter section 6091 is used to receive an external force to cause the valve stem 609 to move, and a second annular cavity 618 is formed between the second small diameter section 6091 and the second valve sleeve 608.

The valve body 607 is provided with an oil inlet passage 616 communicating with the valve ball cavity, and the valve body 607 is also provided with an oil discharge passage 617. Normally, when the solenoid pilot valve is in the closed state, the valve ball 611 is in the top block 612 The valve port is sealed under the elastic top pressure, blocking the oil inlet passage 616 and the oil discharge passage 617.

The oil drain passage 617 and the first annular cavity 620 are communicated through the interval 622, so the interval 622 actually constitutes the first communication structure provided on the valve sleeve. When the valve stem 609 pushes the valve ball 611 under an external force, the solenoid pilot valve opens, and the oil inlet passage 616 communicates with the oil discharge passage 617 through the valve ball cavity and the first annular cavity 620, and the oil can be discharged. In order to facilitate the oil discharge, the first small-diameter section 6093 and the large-diameter section 6092 are transitioned through a tapered surface 6094, and the tapered surface 6094 corresponds to the position where the gap 622 is located.

The valve body 607 is also provided with a bypass oil passage 615. One end of the bypass oil passage 615 is in communication with the oil inlet passage 616, and the other end is in communication with the second annular cavity 618. For this reason, a bypass is provided on the second valve sleeve 608. A second communication structure in which the oil passage 615 communicates with the second annular cavity 618. The second communication structure includes an annular groove 621 provided on the outer peripheral surface of the second valve sleeve 608 and a plurality of communication spaces arranged at the bottom of the annular groove 621 The hole 614 is arranged in such a structure to facilitate the oil in the bypass oil passage 615 to enter the second annular cavity 618.

The bypass oil passage 615 is composed of two intersecting intersecting oil passages, and the two intersecting oil passages are in the shape of "in", which is not only convenient for processing, but also convenient for oil to enter the second annular cavity. In addition, an end plate 606 is provided at the end of the second valve sleeve 608, and the end plate 606 is fixedly connected to the second valve sleeve 608 and the valve body 607, and the second small diameter section 6091 is guided and slidingly fitted with the inner hole of the end plate 606.

As shown in FIG. 2, the first opening solenoid pilot valve 600 also includes a lever housing 623, which is located between the electromagnet housing 601 and the valve body 607 of the pilot valve. The lever housing 623 and the electromagnet housing 623 are respectively connected to the valve body 607 of the pilot valve. The body 601 is fixedly connected with the valve body 607 of the pilot valve. The lever housing 623 is provided with a lever 604. One end of the lever 604 is rotatably assembled on the lever housing 623, and the other end is pushed to fit with the moving iron core 602 of the electromagnet. The lever 604 is also provided with the valve stem 609 of the pilot valve. The mating part is such that when the movable iron core 602 pushes the lever 604 to rotate, the mating part of the lever 604 pushes the valve stem 609 to move.

The lever 604 in this embodiment is L-shaped, and the end of one side is rotatably assembled on the lever housing 623, and the end of the other side is push-fitted with the moving iron core 602 of the electromagnet. This shape makes the moving iron The axial direction of the core 602 and the axial direction of the valve stem 609 can be perpendicular to each other, which can reduce the overall height of the solenoid pilot valve and facilitate assembly and arrangement.

As shown in FIG. 5, FIG. 6 and FIG. 7, the main valve includes a valve seat 100 and end caps 400 fixed on both ends of the valve seat 100. The valve seat 100 has a cylindrical structure with a central hole 114 therein. The cylinder wall of the valve seat 100 is sequentially provided with a low-pressure oil chamber 110 for communicating with a low-pressure oil tank (not shown in the figure), a hydraulic cylinder oil chamber 111 for communicating with a hydraulic cylinder (not shown in the figure), and The high-pressure oil chamber 112, the low-pressure oil chamber 110, the hydraulic cylinder oil chamber 111, and the high-pressure oil chamber 112 that communicate with the high-pressure hydraulic system (not shown in the figure) are all communicated with the central hole 114 of the valve seat 100.

The central hole 114 of the valve seat 100 is equipped with a low-pressure chamber valve sleeve 200 corresponding to the low-pressure oil chamber 110, a high-pressure chamber valve sleeve 300 corresponding to the high-pressure oil chamber 112, and the low-pressure chamber valve sleeve 200 and the high-pressure chamber valve sleeve 300 are installed in Spool 500. The low pressure chamber valve sleeve 200 is provided with a first through hole 201 penetrating along the radial direction of the low pressure chamber valve sleeve 200, and the first through hole 201 is disposed opposite to the low pressure oil chamber 110. The high pressure chamber valve sleeve 300 is provided with a second through hole 301 penetrating in the radial direction of the high pressure chamber valve sleeve 300, and the second through hole 301 is disposed opposite to the high pressure oil chamber 112. The low-pressure chamber valve sleeve 200 and the high-pressure chamber valve sleeve 300 have a gap in the axial direction of the valve seat 100, and the gap forms an annulus 113, and the annulus 113 is arranged opposite to the hydraulic cylinder oil chamber 111.

In fact, the structure and arrangement of the valve core 500, the low-pressure chamber valve sleeve 200, the high-pressure chamber valve sleeve 300, the low-pressure oil chamber 110, the hydraulic cylinder oil chamber 111, and the high-pressure oil chamber 112 are the same as those in the prior art, and will not be repeated here. Go into details.

The difference is that the inner wall of the valve seat 100 is provided with a first oil passage 101 extending in the axial direction of the valve seat 100, and the inner wall of the valve seat 100 is also provided with four branch oil passages communicating with the first oil passage 101 , Respectively, are the second oil passage 102, the fifth oil passage 105, the sixth oil passage 106, and the ninth oil passage 109. In addition, the inner wall of the valve seat 100 is provided with four independent oil passages that are not cross-connected with the first oil passage 101, namely the third oil passage 103, the fourth oil passage 104, and the seventh oil passage. 107 and the eighth oil passage 108.

The second oil passage 102 communicates with the oil inlet passage of the first opening electromagnetic pilot valve 600, the third oil passage 103 communicates with the oil discharge passage of the first opening electromagnetic pilot valve 600; the fourth oil passage 104 is connected with the second oil passage. The oil discharge passage of the opening solenoid pilot valve 700 is connected, the fifth oil passage 105 is connected to the oil inlet passage of the second opening solenoid pilot valve 700; the sixth oil passage 106 is connected to the oil discharge passage of the first closing solenoid pilot valve 800 The seventh oil passage 107 communicates with the oil inlet passage of the first closing solenoid pilot valve 800; the eighth oil passage 108 communicates with the oil inlet passage of the second closing solenoid pilot valve 900, and the ninth oil passage 109 communicates with the second The oil discharge passage of the closing solenoid pilot valve 900 is in communication.

Two opening solenoid pilot valves are set in parallel, and two closing solenoid pilot valves are also set in parallel. They can act independently or at the same time to avoid the failure of the entire electro-hydraulic control valve when one solenoid pilot valve is damaged.

The working principle of the electro-hydraulic control valve in the embodiment of the present invention is:

When the electro-hydraulic control valve is in the closed state for opening action, the initial position is shown in Figure 7. The electromagnets of the first opening solenoid pilot valve 600 and/or the second opening solenoid pilot valve 700 are attracted after receiving the command. Take the first opening electromagnetic pilot valve 600 as an example. As shown in Figures 2 and 3, the moving iron core 602 of the first opening electromagnetic pilot valve 600 moves downwards, and the lever 604 pushes the valve stem 609 to overcome the ball holder The reaction force and the oil pressure from the oil inlet passage 616 and the valve ball cavity move to the right to open the valve ball 611, the first opening solenoid pilot valve 600 opens, and the oil inlet passage 616 and the oil discharge passage 617 are connected.

At this time, the high-pressure oil in the cavity A at the right end of the main valve sequentially enters the first opening solenoid pilot valve 600 through the first oil passage 101 and the second oil passage 102 on the main valve seat 100, and passes through the third oil passage 103 in turn. , The first through hole 201, the low-pressure oil chamber 110 are discharged into the low-pressure oil tank, so that the right end of the main valve spool 500 is relieved of pressure, while the spool 500 moves to the right under the action of the high-pressure oil in the cavity B at the left end, and the spool 500 interacts with the high pressure The cavity valve sleeve 300 is in sealed contact, as shown in Figure 6, when the hydraulic cylinder oil cavity 111 is in communication with the low pressure oil cavity 110, so that the high pressure oil on the opening side of the hydraulic cylinder is discharged into the low pressure oil tank through the low pressure oil cavity 110 for opening action .

When the electro-hydraulic control valve is in the open state for closing action, the initial position is shown in Figure 6. The electromagnet of the first closing solenoid pilot valve 800 and/or the second closing solenoid pilot valve 900 attracts after receiving the command. Take the first closing solenoid pilot valve 800 as an example. Its moving iron core acts, and the valve stem of the pilot valve is pushed by the lever to push the valve ball open and open the pilot valve. After the pilot valve is opened, the high-pressure oil of the high-pressure hydraulic system sequentially passes through the high-pressure oil chamber 112, the second through hole 301, the seventh oil passage 107 and enters the first closing solenoid pilot valve 800, and then from the sixth oil passage 106, the first oil passage 106, and the first oil passage 107. The oil passage 101 enters the cavity A at the right end of the spool 500, thereby pushing the spool 500 to move to the left, and the spool 500 is in sealing contact with the low-pressure chamber valve sleeve 200, as shown in Figure 7, when the high-pressure oil chamber 112 and the hydraulic cylinder oil The cavity 111 is connected, and the high pressure oil of the high pressure hydraulic system enters the closing side of the hydraulic cylinder through the hydraulic cylinder oil cavity 111 to perform the closing action.

During the opening and closing process of the electro-hydraulic control valve, the action process of the spool 500 is the same as that of the prior art.

The pilot valve in the electromagnetic pilot valve in the embodiment of the present invention is different from the prior art in that the valve body of the pilot valve is provided with a bypass oil passage. The first opening electromagnetic pilot valve 600 is still taken as an example, as shown in Figs. 3 and As shown in 4, when the pilot valve is in the closed state, the valve ball 611 is pressed by the elastic top pressure of the ball holder and the oil pressure entering the valve ball cavity from the oil inlet channel 616 makes the valve ball 611 tightly blocked on the valve port . At the same time, a part of the oil in the oil inlet passage 616 can enter the second annular cavity 618 through the bypass oil passage 615, and act on the large diameter section 6092, thereby exerting a pre-movement on the valve stem 609 in the direction of the valve ball 611. The thrust, that is, a part of the force is applied to the valve stem 609 in advance, so that the actual value of the external force required to make the valve stem 609 actually move can be reduced.

In other words, if the applied external force value is constant, the valve stem 609 of the pilot valve in the embodiment of the present invention is easier to move, the movement speed will be faster, and it is easier to push the valve ball 611 open. With this support , Can increase the diameter of the pilot valve, and then increase the flow rate. Therefore, the diameter and flow rate of the pilot valve in the embodiment of the present invention can meet the action time of the main valve, and can directly drive the main valve to move, eliminating the need for the amplification valve in the prior art, so that the use requirements can be guaranteed. , Simplify the structure of the electro-hydraulic control valve.

In other embodiments of the electro-hydraulic control valve, the lever is not L-shaped, but a straight rod. At this time, the axial direction of the moving iron core is parallel to the axial direction of the valve stem.

In other embodiments of the electro-hydraulic control valve, the electromagnetic pilot valve does not include a lever housing and a lever, and the moving iron core of the electromagnet directly drives the valve stem of the pilot valve to act.

In other embodiments of the electro-hydraulic control valve, the bypass oil passage may be L-shaped or arc-shaped.

In other embodiments of the electro-hydraulic control valve, the transition between the first small-diameter section and the large-diameter section is not a conical surface transition, but directly a stepped surface transition, and the stepped surface is perpendicular to the first small-diameter section and the large-diameter section.

In other embodiments of the electro-hydraulic control valve, the second communication structure may only be a communication hole, and it is necessary to ensure that the communication hole is aligned and communicated with the bypass oil passage during installation.

In other embodiments of the electro-hydraulic control valve, the valve sleeve is not a separate piece but an integral piece, and the first communication structure is a communication hole opened on the valve sleeve.

In other embodiments of the electro-hydraulic control valve, the ball holder may also be composed of a ball holder seat and a spring, the ball holder seat is press-fitted with the valve ball, and the ball holder seat is guided and slidably installed in the valve body of the pilot valve.

In other embodiments of the electro-hydraulic control valve, one end of the bypass oil passage may also be in communication with the valve ball cavity, as long as the oil entering the valve body of the pilot valve can be introduced into the second annular cavity.

The embodiment of the electromagnetic pilot valve in the embodiment of the present invention is: the specific structure of the electromagnetic pilot valve is the same as the electromagnetic pilot valve in the above embodiment of the electro-hydraulic control valve, and will not be repeated here.

The embodiment of the pilot valve in the embodiment of the present invention is: the specific structure of the pilot valve is the same as the pilot valve in the electromagnetic pilot valve in the embodiment of the electro-hydraulic control valve, and will not be repeated here. In addition, in other embodiments of the pilot valve, the external force applied to the valve stem of the pilot valve may not be the moving iron core of the electromagnet, but may also be other components capable of outputting direct action, such as an electric push rod.

Claims

A pilot valve including:

Valve body

The valve sleeve is fixed in the valve body, the valve sleeve has an inner hole, and one end of the inner hole is the valve port;

The valve ball cavity is arranged in the valve body and located on one side of the valve port, and a valve ball is arranged in the valve ball cavity;

The ball holder is installed on the valve body and is used to elastically press-fit the valve ball so that the valve ball can block the valve port;

The oil inlet channel is arranged on the valve body, and the oil inlet channel is in communication with the valve ball cavity;

The oil drain channel is arranged on the valve body, and the oil drain channel is in communication with the inner hole of the valve sleeve;

The valve stem is installed in the valve sleeve for guiding movement. The valve stem is used to move in the valve sleeve by external force and push the valve ball, so that the oil inlet channel is connected with the oil discharge channel through the inner hole of the valve sleeve;

Among them, the valve stem includes a large diameter section in the middle and a first small diameter section and a second small diameter section located on both sides of the large diameter section. The large diameter section is in sliding fit with the valve sleeve. The first small diameter section is used to push the valve ball. A first annular cavity is formed between the small diameter section and the valve sleeve. The first annular cavity communicates with the oil discharge channel through a first communication structure provided on the valve sleeve. The second small diameter section is used to receive external forces. A second annular cavity is formed between the valve sleeves;

The pilot valve also includes:

The bypass oil passage is arranged in the valve body. One end of the bypass oil passage is connected with the oil inlet passage or the valve ball cavity, and the other end is connected with the second annular cavity, so that a part of the oil in the oil inlet passage or the valve ball cavity can be It enters the second annular cavity through the bypass oil passage, and applies a pre-thrust to the valve stem moving toward the valve ball; the valve sleeve is provided with a second communication structure for communicating the bypass oil passage with the second annular cavity.
The pilot valve according to claim 1, the valve sleeve includes a first valve sleeve and a second valve sleeve arranged at intervals, the valve port is located on the first valve sleeve, and the large diameter section of the valve stem and the second valve sleeve guide sliding Match, the first annular cavity is enclosed by the first small diameter section and the first valve sleeve, the second annular cavity is enclosed by the second small diameter section and the second valve sleeve, and the interval between the first valve sleeve and the second valve sleeve is formed The first communication structure and the second communication structure are arranged on the second valve sleeve.
According to the pilot valve of claim 1 or 2, the second communication structure includes a ring groove provided on the outer circumferential surface of the valve sleeve and a plurality of communication holes arranged at intervals at the bottom of the ring groove.
According to the pilot valve of claim 1 or 2, the first small-diameter section and the large-diameter section are transitioned by a tapered surface, and the tapered surface corresponds to the position where the first communication structure is located.
The pilot valve according to claim 1 or 2, wherein the bypass oil passage is composed of two intersecting intersecting oil passages, and the two intersecting oil passages are in the shape of "in".
An electromagnetic pilot valve includes an electromagnet. The electromagnet includes an electromagnet casing and a moving iron core arranged in the electromagnet casing. The moving iron core is used to provide an external force. The electromagnetic pilot valve further includes fixing to the electromagnet casing The pilot valve according to any one of claims 1 to 5 is connected.
The electromagnetic pilot valve according to claim 6, the electromagnetic pilot valve further comprising a lever housing, the lever housing is located between the electromagnet housing and the valve body of the pilot valve, the lever housing is connected to the electromagnet housing and the pilot valve respectively The valve body is fixedly connected. A lever is arranged in the lever housing. One end of the lever is rotatably assembled on the lever housing, and the other end is push-fitted with the moving iron core of the electromagnet. The lever also has a push-fit fit with the valve stem of the pilot valve When the moving iron core pushes the lever to rotate, the matching part of the lever pushes the valve stem to move.
The electromagnetic pilot valve according to claim 7, wherein the lever is L-shaped, and the axial direction of the movable iron core is perpendicular to the axial direction of the valve stem.
An electro-hydraulic control valve for a hydraulic operating mechanism, comprising a main valve and the electromagnetic pilot valve according to any one of claims 6 to 8 connected with the main valve.