CN218178004U

CN218178004U - Bidirectional electromagnetic pressure-maintaining unloading valve

Info

Publication number: CN218178004U
Application number: CN202222714236.4U
Authority: CN
Inventors: 杨洪新; 杨莉
Original assignee: Changzhou Wenli Automation Co ltd
Current assignee: Changzhou Wenli Automation Co ltd
Priority date: 2022-10-13
Filing date: 2022-10-13
Publication date: 2022-12-30
Anticipated expiration: 2032-10-13

Abstract

The utility model relates to a two-way electromagnetism pressurize unloading valve, this scheme include three-position four-way solenoid directional valve, are equipped with a side electro-magnet, B side electro-magnet, A passageway, B passageway, P passageway and T passageway, still include: the main valve body is provided with an A1 oil inlet/outlet passage cavity, a B1 oil inlet/outlet passage cavity, an A2 oil inlet/outlet passage cavity, a B2 oil inlet/outlet passage cavity, an oil inlet P and an oil return T; and the two hydraulic control one-way valves are respectively arranged between the A1 oil inlet/outlet passage cavity and the B1 oil inlet/outlet passage cavity and between the A2 oil inlet/outlet passage cavity and the B2 oil inlet/outlet passage cavity. The hydraulic system can be used for bypass unloading oil return in a hydraulic loop of a bidirectional high-pressure large-flow hydraulic system, and is matched with a large-flow Y function or H function slide valve type direction valve to perform zero-leakage bidirectional pressure maintaining and non-impact unloading oil return.

Description

Bidirectional electromagnetic pressure-maintaining unloading valve

Technical Field

The utility model relates to the technical field of valves, concretely relates to two-way electromagnetism pressurize unloading valve.

Background

At present, the pressure-maintaining unloading valve in the prior art is usually of a single-channel type, and the pressure is usually 31.5MPa. The unloading impact is large in high-pressure large-flow use occasions. In some high-pressure occasions, a corresponding valve cannot be selected, and only a manual ball valve operation is selected for replacement.

Because the prior art has lower pressure and large impact, the hydraulic system cannot be used for model selection in a high-pressure high-flow system with the high pressure of more than 40MPa, and particularly needs to be separately installed in a bidirectional hydraulic loop, so that the whole hydraulic system has the disadvantages of non-compact structure, poor integration and inconvenient installation.

Therefore, a bidirectional electromagnetic pressure maintaining and unloading valve is needed to solve a series of problems of two channels, bidirectional pressure maintaining, no-impact unloading and oil return and the like in a hydraulic circuit of a hydraulic system in the situation of requiring high pressure and large flow.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a two-way electromagnetism pressurize off-load valve to the above-mentioned problem that exists among the prior art.

In order to realize the purpose of the utility model, the utility model adopts the following technical scheme: the two-way electromagnetic pressure maintaining unloading valve comprises a three-position four-way electromagnetic reversing valve, an a-side electromagnet, a B-side electromagnet, an A channel, a B channel, a P channel and a T channel, and further comprises:

the main valve body is provided with an A1 oil inlet and outlet passage cavity and a B1 oil inlet and outlet passage cavity which are communicated with the A passage, an A2 oil inlet and outlet passage cavity and a B2 oil inlet and outlet passage cavity which are communicated with the B passage, an oil inlet P communicated with the P passage and an oil return T communicated with the T passage, wherein the oil inlet P is connected with a pressure oil source, and the oil return T is connected with an oil tank;

the two hydraulic control one-way valves are respectively arranged between the A1 oil inlet/outlet passage cavity and the B1 oil inlet/outlet passage cavity and between the A2 oil inlet/outlet passage cavity and the B2 oil inlet/outlet passage cavity;

the first path of channel is formed by the A1 oil inlet/outlet channel cavity and the B1 oil inlet/outlet channel cavity, and the second path of channel is formed by the A2 oil inlet/outlet channel cavity and the B2 oil inlet/outlet channel cavity;

when the three-position four-way electromagnetic directional valve is in the middle position, under the action of the two hydraulic control one-way valves, the liquid flow in the direction from the A1 oil inlet/outlet passage cavity to the B1 oil inlet/outlet passage cavity and in the direction from the A2 oil inlet/outlet passage cavity to the B2 oil inlet/outlet passage cavity is stopped;

when an electromagnet at the side b of the three-position four-way electromagnetic reversing valve is electrified, the pressure oil source is switched to the channel A, so that the hydraulic control one-way valve at the side a acts to realize the bidirectional through flow of the first channel, and the first channel is in an unloading function opening state;

when the electromagnet on the side a of the three-position four-way electromagnetic reversing valve is electrified, the pressure oil source is switched to the channel B, so that the hydraulic control one-way valve on the side B acts to realize the bidirectional through flow of the second channel, and the second channel is in an unloading function opening state.

Furthermore, each hydraulic control one-way valve is a spiral type plug-in hydraulic control one-way valve and is symmetrically arranged on two sides of the main valve body.

The hydraulic control one-way valve is different from a common one-way valve in that one more control oil way is arranged, when the control oil way is not communicated with pressure oil, the hydraulic control one-way valve works like the common one-way valve, and the pressure oil only flows to an oil outlet from an oil inlet and cannot flow reversely. When control pressure is input into the control oil path, the piston mandril moves rightwards under the action of pressure oil, and the one-way valve is jacked open by the mandril, so that the oil inlet and the oil outlet are communicated. If the oil outlet is larger than the oil inlet, the oil can flow reversely. And the spiral inserted hydraulic control one-way valve can be more conveniently installed in the main valve body, has a simple structure and is easier to disassemble, assemble and maintain.

Furthermore, a flange plug and a sealing ring are arranged outside each hydraulic control one-way valve, and each hydraulic control one-way valve is sealed in the main valve body through the flange plug and the sealing ring.

Furthermore, the main valve core of each hydraulic control one-way valve is a ball valve core with pre-unloading function.

Furthermore, the main valve body is internally provided with an O-shaped ring and a corresponding step, and the close contact between the step and the shoulder of the mounting bottom hole of the main valve body realizes the sealing between the oil inlet and outlet ports A1 and B1 and the sealing between the oil inlet and outlet ports A2 and B2, so that an oil inlet and outlet cavity A1, an oil inlet and outlet cavity B1, an oil inlet and outlet cavity A2 and an oil inlet and outlet cavity B2 are formed. Namely, the first channel and the second channel respectively screw the two spiral plug-in type hydraulic control one-way valve components into the main valve body mounting screw holes (the step of the valve body is provided with an O-shaped sealing ring, and the sealing between the oil inlet and outlet channels is realized through the close contact between the step of the valve body and the shoulder of the main valve body mounting bottom hole).

Furthermore, a plurality of oil duct process hole plugs are arranged on the main valve body, and the control oil ducts on the first channel and the second channel are plugged by the oil duct process hole plugs to be separated from the outside.

Furthermore, the main valve body is provided with a plurality of mounting screw holes. The main valve body can be conveniently installed on other parts.

Further, the pre-unloading control ratio of each hydraulic control one-way valve is 10-26.

Furthermore, the main material of the main valve body is 42CrMo, and the design pressure is 500bar. The test pressure is not lower than 630bar.

The cover plate is used for replacing the three-position four-way electromagnetic reversing valve, an A port control oil passage threaded interface and a B port control oil passage threaded interface are arranged on the cover plate and are respectively and correspondingly connected with the control oil passages of the first channel and the second channel, and the A port control oil passage threaded interface and the B port control oil passage threaded interface are respectively used for connecting a pressure oil source to the hydraulic control one-way valve damping hole to the main valve core piston channel.

According to the arrangement, the three-position four-way electromagnetic reversing valve can be detached according to the requirements of the use working condition, then the cover plate is arranged on the main valve body, and the port A control oil passage and the port B control oil passage are respectively connected with the variable pressure oil source, so that the remote control is realized.

The working principle and the beneficial effects are as follows: 1. compared with the prior art, the bidirectional electromagnetic pressure maintaining unloading valve can realize bidirectional pressure maintaining, high-pressure impact-free unloading, bypass unloading and low-pressure control high pressure under the bidirectional high-pressure large-flow scene. The control oil path (the oil path in the three-position four-way electromagnetic directional valve) and the main oil path (the first path channel and the second path channel) are formed by two oil paths which are not interfered with each other, the valve core has a large control pressure ratio, and then an energy accumulator or a low-pressure small-flow hydraulic pump can be used as an external pressure oil source, so that unloading and oil return of the main oil path under the pressure maintaining state of the main oil path A1 or A2 can be realized. Under the working condition, energy can be saved, and the production cost can be reduced;

2. compared with the prior art, when the three-position four-way electromagnetic reversing valve is in the middle position, under the action of the two hydraulic control one-way valves, after the liquid flow in the direction from the A1 oil inlet/outlet passage cavity to the B1 oil inlet/outlet passage cavity and in the direction from the A2 oil inlet/outlet passage cavity to the B2 oil inlet/outlet passage cavity is stopped, the A1 oil inlet/outlet passage cavity and the A2 oil inlet/outlet passage cavity are pressurized, so that the leakage-free pressure maintaining effect is realized, and the pressure maintaining effect is further realized;

3. compared with the prior art, when an external pressure oil source passes through an oil inlet P and an oil return port T is connected to a B-side electromagnet of a rear three-position four-way electromagnetic reversing valve in an electrified mode, the electromagnetic valve can be switched to a mode of P → A and a mode of B → T, pressure oil pushes an a-side hydraulic control one-way valve to act through a control oil duct A, so that the hydraulic control one-way valve has a pre-unloading function in a pressurizing or pressure maintaining state of an A1 oil inlet and outlet channel cavity, and the oil can be unloaded from the A1 oil inlet and outlet channel cavity to the B1 oil inlet and outlet channel cavity without impact and returned to an oil tank; when an electromagnet on the a side of the three-position four-way electromagnetic reversing valve is electrified, the electromagnetic reversing valve can be switched to a P → B way and an A → T way, pressure oil pushes a hydraulic control one-way valve on the B side to act through a control oil passage B, and then the hydraulic control one-way valve has a pre-unloading function in the pressurizing or pressure maintaining state of an A2 oil inlet and outlet channel cavity, so that the oil can be unloaded and returned to an oil tank without impact from the A2 oil inlet and outlet channel cavity to the B2 oil inlet and outlet channel cavity; the function is switched by the three-position four-way electromagnetic valve, and then the function is converted, so that the two-way unloading oil return function is realized.

Compared with the prior art, because the screw-type plug-in hydraulic control one-way valve is adopted as the component, the hydraulic control one-way valve has the advantages of compact structure, good sealing performance, easy installation and maintenance and zero high-pressure leakage, and the integral structure of the hydraulic control one-way valve is combined, so that the degree of compact structure can be further improved, and split installation is not needed in a hydraulic system, thereby solving the problems that the structure is not compact, the integration is poor, the installation and the use are inconvenient, and the requirements of certain high-pressure high-flow two-way external control type systems cannot be met.

Drawings

Fig. 1 is a schematic structural diagram of the present invention;

FIG. 2 is an oil circuit diagram of FIG. 1;

FIG. 3 is a three-view illustration of FIG. 1;

FIG. 4 is a schematic structural diagram of another embodiment of the present invention;

FIG. 5 is the oil circuit diagram of FIG. 4;

FIG. 6 is a three-dimensional view of FIG. 4;

fig. 7 is a partially enlarged view of fig. 1.

In the figure, 1, a three-position four-way electromagnetic directional valve; 2. controlling a process hole plug of an oil passage B of the oil port; 4. a first flange plug; 5. a first orifice; 6. a main valve body; 7. a first screw cylinder; 8. a first piston; 9. a first return spring; 10. a first main push rod; 11. a first O-ring; 12. b2, an oil inlet and outlet passage cavity; 13. a first pre-unloading thimble; 14. a second O-ring; 15. a first main spool; 16. first pre-unloading steel balls; 17. a first spring seat; 18. a first pagoda spring; 19. a first spring seat nut; 20. a2, an oil inlet and outlet passage cavity; 21. an oil return port T; 22. an oil inlet P; 23. controlling the oil duct A oil duct fabrication hole plug; 25. a second flange plug; 26. a second orifice; 27. a second screw cylinder; 28. a second piston; 29. a second return spring; 30. a second main push rod; 31. a third O-ring; 32. b1, an oil inlet and outlet passage cavity; 33. a second pre-unloading thimble; 34. a fourth O-ring; 35. a second main spool; 36. a second pre-discharge steel ball; 37. a second spring seat; 38. a second pagoda spring; 39. a second spring seat nut; 40. a1, an oil inlet and outlet passage cavity; 41. a first valve seat; 42. a second valve seat; 43. a side electromagnet; 44. b side electromagnet; 45. mounting a screw hole; 46. a cover plate; 47. the port A controls the oil duct; 48. and the port B controls the oil duct.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art all belong to the protection scope of the present invention.

It will be understood by those skilled in the art that in the present disclosure, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in an orientation or positional relationship indicated in the drawings for ease of description and simplicity of description, and do not indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be considered limiting.

As shown in fig. 1 to 3 and fig. 7, the bidirectional electromagnetic pressure-maintaining unloading valve includes:

the three-position four-way electromagnetic directional valve 1 is provided with an a-side electromagnet 43, a B-side electromagnet 44, an A channel, a B channel, a P channel and a T channel;

in this embodiment, the three-position four-way electromagnetic directional valve 1 is a product in the prior art, can be directly purchased from the market, is a conversion element between a hydraulic control system and an electrical appliance control system, realizes the movement of a valve core by utilizing the suction force of electromagnets at two ends, and changes the on-off of an oil path, thereby realizing the reversing of an execution element. And "three-position four-way" is understood to mean: "three-position" refers to a valve core, and the valve core can realize the conversion of three positions. The four-way valve can realize the through among four oil ports in different modes in terms of functions. For example, in this example, the three-position four-way electromagnetic directional valve 1 with a "Y" functional valve element is used. The valve core can realize the conversion of the left position, the middle position and the right position. When the valve core is in the middle position, the P oil port channels are not communicated, and the A channel, the B channel and the T channel are communicated. When the valve core is in the left position, the oil path can enter the channel A from the channel P and then exit from the channel A, and the channel B is communicated with the channel T. When the valve core is at right position, the oil path can be led in from channel P to channel B and led out from channel A to channel T.

Therefore, the internal structure and the principle of the three-position four-way electromagnetic reversing valve are also the prior art, the description of the internal structure and the principle is omitted, and the functions and the characteristics of the three-position four-way electromagnetic reversing valve are utilized, namely the direction is switched through the three-position four-way electromagnetic reversing valve 1 through an external pressure oil source. And choose for use this product to have the mature technique, low cost's advantage, in case damage can directly follow main valve body 6 and pull down the change, the maintenance cost is low, simple structure.

The main valve body 6 is provided with an A1 oil inlet and outlet passage cavity 40 and a B1 oil inlet and outlet passage cavity 32 which are communicated with the A passage, an A2 oil inlet and outlet passage cavity 20 and a B2 oil inlet and outlet passage cavity 12 which are communicated with the B passage, an oil inlet P22 communicated with the P passage and an oil return T21 communicated with the T passage, the oil inlet P22 is connected with a pressure oil source, and the oil return T21 is connected with an oil tank;

in this embodiment, an oil passage matched with four passages of the three-position four-way electromagnetic directional valve 1 and a cavity for installing a pilot operated check valve assembly are arranged in the main valve body 6.

Preferably, the main valve body 6 is made of high-strength alloy steel 42CrMo, and is subjected to heat treatment process and finish machining. The design pressure is 500bar, the high-pressure high-strength test of 630bar can be resisted, and the safety is high.

The two hydraulic control one-way valves are respectively arranged between the A1 oil inlet/outlet passage cavity 40 and the B1 oil inlet/outlet passage cavity 32 and between the A2 oil inlet/outlet passage cavity 20 and the B2 oil inlet/outlet passage cavity 12;

in this embodiment, the two-way pilot operated check valve may be made of a product of the existing german hawey or other manufacturers, which is not limited herein, and this type of spiral cartridge pilot operated check valve with a pre-unloading function is used as a valve core of the main valve body 6. The valve core has the advantages of high design pressure, mature technology, simple installation, convenient maintenance, compact structure, good sealing performance and high integration. The utility model discloses a performance and reliability have been ensured.

The hydraulic control one-way valve is different from a common one-way valve in that a control oil way is added, when the control oil way is not communicated with pressure oil, the hydraulic control one-way valve works like the common one-way valve, and the pressure oil only flows from an oil inlet to an oil outlet and cannot reversely flow. When the control pressure is input into the control oil path, the piston ejector rod moves under the action of the pressure oil, and the one-way valve is ejected by the ejector rod to connect the oil inlet and the oil outlet. If the oil outlet is larger than the oil inlet, the oil can flow reversely. And the spiral inserting type hydraulic control one-way valve can be more conveniently installed in the main valve body 6, and has simple structure and convenient assembly and disassembly.

The pre-unloading valve core is a ball type small one-way valve arranged in the main valve core (the valve port end is spherical), and the valve seat is arranged on the inner cavity of the main valve core. Before the main valve opening is opened, the small ball one-way valve is opened in advance, and the formed annular gap plays a throttling role, so that non-impact (pre) unloading is realized.

Specifically, each spiral type plug-in hydraulic control check valve comprises a damping hole, a spiral cylinder, a piston, a return spring, a main push rod, an O-shaped ring, a pre-unloading thimble, a main valve core, a pre-unloading steel ball, a spring seat, a pagoda spring, a spring seat nut and the like.

If the hydraulic control one-way valve positioned on the side b comprises a first damping hole 5, a first spiral cylinder 7, a first piston 8, a first return spring 9, a first main push rod 10, a first O-shaped ring 11, a first pre-unloading ejector pin 13, a second O-shaped ring 14, a first main valve core 15, a first pre-unloading steel ball 16, a first spring seat 17, a first pagoda spring 18, a first spring seat nut 19 and the like.

The hydraulic control one-way valve positioned on the side a comprises a second damping hole 26, a second spiral cylinder 27, a second piston 28, a second return spring 29, a second main push rod 30, a third O-ring 31, a second pre-unloading thimble 33, a fourth O-ring 34, a second main valve core 35, a second pre-unloading steel ball, a second spring seat 37, a second pagoda spring 38, a second spring seat nut 39 and the like.

The A1 oil inlet/outlet passage cavity 40 and the B1 oil inlet/outlet passage cavity 32 form a first passage, and the A2 oil inlet/outlet passage cavity 20 and the B2 oil inlet/outlet passage cavity 12 form a second passage; namely, the two hydraulic control one-way valves independently control the two channels.

Specifically, each pilot-controlled check valve is provided with a flange plug (a first flange plug 4 and a second flange plug 25) outside, and each pilot-controlled check valve is sealed in the main valve body 6 through the flange plugs. And an O-shaped ring and a valve seat are arranged outside the middle position of each hydraulic control one-way valve, so that the first channel and the second channel can be isolated through the O-shaped ring, the valve seat and the main valve body 6 respectively. The valve seat is used for installing a pilot-controlled check valve, and the O-rings (the second O-ring 14 and the fourth O-ring 34) are arranged on the valve seat (the first valve seat 41 and the second valve seat 42). Just because this application has chooseed the spiral cartridge pilot operated check valve for use, consequently only need two simple and convenient screws of cartridge subassembly to be in main valve body 6 mounting screw hole. The main valve body 6 is provided with steps (a second O-shaped ring 14 and a fourth O-shaped ring 34), and the steps of the valve body are in close contact with the shoulder of the mounting bottom hole of the main valve body 6, so that the oil inlet and outlet ports A1 and B1 are sealed, and the oil inlet and outlet ports A2 and B2 are sealed. Thereby forming an oil inlet and outlet cavity A1 and an oil inlet and outlet cavity B1, an oil inlet and outlet cavity A2 and an oil inlet and outlet cavity B2. Two channels, namely: first channels A1 and B1 channels, and second channels A2 and B2 channels.

Namely, A1-B1 is a first channel, and A2-B2 is a second channel. The first path is isolated by the fourth O-shaped ring 34, the first valve seat 41 and the main valve body 6; the second path is isolated by the second O-ring 14, the second valve seat 42 and the main valve body 6. Thereby forming A1 cavity and a B1 cavity and A2 and B2 cavities.

Preferably, a plurality of oil passage process hole plugs (a control oil port B oil passage process hole plug 2 and a control oil passage a oil passage process hole plug 23) are arranged on the main valve body 6, and the oil passage process holes on the first channel and the second channel are plugged through the oil passage process hole plugs.

As shown in fig. 1 in conjunction with the schematic diagram of fig. 2, when the three-position four-way electromagnetic directional valve 1 is in the neutral position (when the a-side electromagnet 43 and the B-side electromagnet 44 are not charged), under the action of the first pagoda spring 18 and the second pagoda spring 38, the liquid flow in the direction from the A1 oil inlet/outlet passage cavity 40 to the B1 oil inlet/outlet passage cavity 32 (A1 → B1) and in the direction from the A2 oil inlet/outlet passage cavity 20 to the B2 oil inlet/outlet passage cavity 12 (A2 → B2) is stopped according to the characteristics of the pilot operated check valve; under the state, the cavities A1 and A2 can be pressurized without leakage, and then the pressure maintaining effect is achieved.

When the electromagnet 44 on the B side of the three-position four-way electromagnetic directional valve 1 is electrified (left position), P → A is through, B → T is through, and the pressure oil source is switched to the channel A, so that the hydraulic control one-way valve on the a side acts to realize the two-way through flow of the first channel, and the two-way through flow is in the unloading function opening state of the first channel; namely, the direction of a pressure oil source (an oil inlet P22) is switched to the cavity A, the pressure oil source enters the second damping hole 26 through the side a control oil path, the second piston 28, the second main push rod 30 and the second pre-unloading ejector pin 33 are pushed, the second pre-discharge steel ball 36 is opened, and then the second main valve core 35 is opened, so that the through flow of A1 → B1 and the through flow of B1 → A1 are realized. The unloading function opening state of the first channel is realized. At this time, in the state that the cavity A1 is pressurized or pressure maintaining, the cavity A1 can return oil to the oil tank without impact unloading because the second main valve element 35 has a pre-unloading function.

When the electromagnet 43 on the a side of the three-position four-way electromagnetic directional valve 1 is electrified (right position), the pressure oil source is switched to the channel B, so that the hydraulic control one-way valve on the B side acts to realize the two-way through flow of the second channel, and the unloading function of the second channel is in an opening state. Namely, the pressure oil source direction (oil inlet port P22) is towards the cavity B, and the pressure oil source direction (oil inlet port P22) passes through the side B control oil path and enters the first damping hole 5, so that the first piston 8, the first main push rod 10 and the first pre-unloading ejector pin 13 are pushed, the first pre-unloading steel ball 16 is opened, then the first main valve core 15 is opened, and the through flow of A2 → B2 and the through flow of B2 → A2 are realized. And the unloading function of the second channel is in an opening state. At this time, under the state that the A2 cavity is pressurized or pressure maintaining, the A2 cavity can return oil to the oil tank without impact unloading because the first main valve core 15 has the pre-unloading function.

Therefore, the valve body can realize multiple functions of bidirectional pressure maintaining and non-impact unloading after a pressure oil source is reversed through the three-position four-way electromagnetic reversing valve 1.

Referring to fig. 4-6, in other embodiments, the three-position four-way solenoid valve may be removed according to the requirement of the operating condition, the mounting cover plate 46 is connected to the screw hole 47 corresponding to the port a control oil passage and the screw hole 48 corresponding to the port B control oil passage through external pipelines, the on/off of the pressure oil source may be controlled remotely (equal to that the solenoid valve is mounted elsewhere, and the ports a and B are connected by hoses), or the two ends may be controlled remotely while the valve core is opened for unloading.

The three-position four-way electromagnetic reversing valve further comprises a cover plate 46, the cover plate 46 is used for replacing the three-position four-way electromagnetic reversing valve 1 (the installation size is consistent), the cover plate 46 is provided with an A port control oil passage screw hole 47 and a B port control oil passage screw hole 48, and a P port and a T port are plugged. The screw hole 47 and the screw hole 48 are respectively used for connecting the corresponding first channel and second channel external control pipelines. That is, when the port a control oil passage 47 is connected to the pressure oil source, the second piston 28, the second main push rod 30 and the second pre-unloading thimble 33 are pushed to the second damping hole 26 through the cavity a oil passage to open the second main spool 35 after the second pre-unloading steel ball 36 is pushed open. A1 → B1 through flow B1 → A1 through flow. At the moment, the cavity A1 can return oil to the oil tank without impact unloading because the main valve core has a pre-unloading function in a pressurizing or pressure maintaining state.

When the port B control oil duct 48 is connected to a pressure oil source, the port B control oil duct passes through a cavity B oil duct to reach the first damping hole 5, the first piston 8, the first main push rod 10 and the first pre-unloading ejector pin 13 are pushed to open the first pre-unloading steel ball 16, and then the first main valve core 15 is opened. A2 → B2 flow B2 → A2 flow. At the moment, the A2 cavity can return oil to the oil tank without impact unloading because the main valve core has the pre-unloading function in the pressurizing or pressure maintaining state.

The part of the utility model which is not described in detail is the prior art, so the utility model does not detail the part.

It is understood that the terms "a" and "an" should be interpreted as meaning that a number of one element or element is one in one embodiment, while a number of other elements is one in another embodiment, and the terms "a" and "an" should not be interpreted as limiting the number.

Although the terms of the three-position four-way electromagnetic directional valve 1, the control oil port B oil duct process hole plug 2, the first flange plug 4, the first damping hole 5, the main valve body 6, the first spiral cylinder 7, the first piston 8, the first return spring 9, the first main push rod 10, the first O-ring 11, the B2 oil inlet/outlet passage cavity 12, the first pre-unloading thimble 13, the second O-ring 14, the first main valve core 15, the first pre-unloading steel ball 16, the first spring seat 17, the first pagoda spring 18, the first spring seat nut 19, the A2 oil inlet/outlet passage cavity 20, the oil return port T21, the oil inlet port P22, the control oil duct a oil duct process hole plug 23, the second flange plug 25, the second damping hole 26, the second spiral cylinder 27, the second piston 28, the second return spring 29, the second main push rod 30, the third O-ring 31, the B1 oil inlet/outlet passage cavity 32, the second pre-unloading thimble 33, the fourth O-ring 34, the second spiral cylinder 35, the second pre-piston cover plate 36, the second return spring seat B return spring seat cover plate 29, the second main push rod 30, the third O-ring 31, the electromagnet seat spring seat B1 oil inlet/outlet passage cavity, the electromagnet seat side mounting hole 46, the electromagnet 40, the electromagnet seat side electromagnet 40B, the electromagnet mounting hole 46, the electromagnet 40 a, the electromagnet 44, the electromagnet seat side oil outlet side oil duct 40, the electromagnet 40B, but does not exclude the possibility of using other terms. These terms are used merely to more conveniently describe and explain the nature of the present invention; they are to be construed in a manner that is inconsistent with the spirit of the invention.

The present invention is not limited to the above-mentioned preferred embodiments, and any person can obtain other products in various forms without departing from the scope of the present invention, but any change in shape or structure is made, and all the technical solutions identical or similar to the present application fall within the protection scope of the present invention.

Claims

1. Two-way electromagnetism pressurize unloading valve, including three-position four-way electromagnetic directional valve, be equipped with a side electro-magnet, B side electro-magnet, A passageway, B passageway, P passageway and T passageway, its characterized in that still includes:

the oil inlet and outlet passage cavity A1 and the oil inlet and outlet passage cavity B1 form a first passage, and the oil inlet and outlet passage cavity A2 and the oil inlet and outlet passage cavity B2 form a second passage;

when the electromagnet on the side a of the three-position four-way electromagnetic reversing valve is electrified, the pressure oil source is switched to the channel B, so that the hydraulic control one-way valve on the side B acts to realize the bidirectional through flow of the second channel, and the state is the unloading function opening state of the second channel.

2. The bi-directional electromagnetic pressure maintaining unloading valve of claim 1, wherein each pilot operated check valve is a screw-type plug-in pilot operated check valve and is symmetrically arranged on both sides of the main valve body.

3. The bi-directional electromagnetic pressure maintaining unloading valve of claim 2, wherein each hydraulic control one-way valve is externally provided with a flange plug, and each hydraulic control one-way valve is sealed in the main valve body installation hole by the flange plug and is isolated from the outside.

4. The two-way electromagnetic pressure maintaining unloading valve of claim 2, wherein the main valve core of each hydraulic control one-way valve is a valve core with a pre-unloading ball valve.

5. The bidirectional electromagnetic pressure maintaining unloading valve of claim 1, wherein an O-ring and a corresponding step are provided in the main valve body, and the step is in close contact with a shoulder of a mounting bottom hole of the main valve body to seal the oil inlet/outlet ports A1 and B1 and the oil inlet/outlet ports A2 and B2, so as to form an oil inlet/outlet cavity A1, an oil inlet/outlet cavity B1, an oil inlet/outlet cavity A2 and an oil inlet/outlet cavity B2.

6. The bi-directional electromagnetic pressure maintaining and unloading valve according to claim 1, wherein a plurality of oil passage process hole plugs are provided on the main valve body, and the first passage control oil passage and the second passage control oil passage are separated from the outside by the oil passage process hole plugs.

7. The bi-directional electromagnetic pressure maintaining and unloading valve of claim 1, wherein the main valve body is provided with a plurality of mounting screw holes.

8. The bi-directional electromagnetic pressure maintaining and unloading valve according to any one of claims 1-7, wherein the pre-unloading ratio of each pilot-controlled check valve is 10-26.

9. The bidirectional electromagnetic pressure maintaining and unloading valve of any one of claims 1 to 7, wherein the main valve body is made of 42CrMo.

10. The two-way electromagnetic pressure maintaining unloading valve according to any one of claims 1-7, further comprising a cover plate for replacing the three-position four-way electromagnetic directional valve, and the cover plate is provided with an a port control oil passage threaded interface and a B port control oil passage threaded interface, which are respectively and correspondingly connected with the control oil passages of the first channel and the second channel, and the a port control oil passage threaded interface and the B port control oil passage threaded interface are respectively connected to a pressure oil source, a hydraulic control one-way valve damping hole and a main valve core piston channel.