Direct-acting buffer electromagnetic valve and hydraulic system

Abstract

The invention relates to the technical field of electromagnetic valves, and provides a direct-acting buffer electromagnetic valve which comprises an electromagnetic valve body, and the electromagnetic valve body comprises a sleeve, a valve element and a push rod. The valve element is installed in the installation groove in a sliding mode, a communicating groove used for communicating with the liquid outlet is formed in one end of the valve element, and a communicating hole used for communicating with the liquid inlet is formed in the side wall of the valve element. A pressure feedback cavity is formed in the sleeve and communicates with the sliding groove through the connecting groove. The push rod is slidably installed in the pressure feedback cavity, one end of the push rod penetrates through the connecting groove and is connected with the valve element, and the sleeve is provided with an electromagnetic assembly used for driving the push rod to slide; the valve element is provided with a first feedback channel communicating with the communicating groove, and the push rod is provided with a second feedback channel used for communicating the pressure feedback cavity with the first feedback channel. According to the direct-acting type buffering electromagnetic valve, the situation that a driving motor is damaged can be reduced, and the service life of an excavator is prolonged. The invention further provides a hydraulic system.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electromagnetic valves, in particular to a direct-acting buffer electromagnetic valve and a hydraulic system. BACKGROUND

[0002] The hydraulic system is the core power and control unit of the excavator, and its performance directly affects the operation efficiency, controllability and reliability of the whole machine. In the hydraulic system of the excavator, electromagnetic valves are widely used to control the start and stop and direction change of the execution elements such as the swing motor, the walking motor and the oil cylinder of each working device (such as the boom, the stick and the bucket). In order to control the large flow oil way, the pilot electromagnetic valve is generally used in the hydraulic system of the excavator. Referring to Figure 1 , the existing pilot electromagnetic valve includes a valve body 7, a main valve core 71, a pilot valve core 72 and an electromagnetic driving part, the valve body 7 is provided with an outlet 131 and an inlet 132, and the main valve core 71 is slidingly arranged in a main valve cavity of the valve body 7; one end of the main valve core 71 is provided with a closed control cavity 76, the control cavity 76 is always communicated with the inlet 132 through a throttling passage 73 arranged in the valve body 7 or the main valve core 71; the pilot valve core 72 is usually a small sliding valve or a cone valve located in the control cavity 76 and is directly driven by an electromagnet. The pilot valve core 72 controls the opening and closing of a drain passage 75, and the drain passage 75 connects the control cavity 76 with the outlet 131.

[0003] When the excavator needs to perform a composite action or drive a large inertia component (such as starting of the swing platform), the controller issues an instruction to energize the electromagnet, the pilot valve core 72 is driven to quickly open the drain passage 75. The high-pressure fluid in the control cavity 76 is immediately discharged to the outlet 131 through the drain passage 75, causing the pressure in the control cavity 76 to drop sharply. At this time, the other end of the main valve core 71 still bears the system pressure, and the pressure difference forms a large net thrust, which overcomes the spring force to quickly open the main valve core 71 in a few milliseconds, completing the oil way switching.

[0004] When used to control the pressure-sensitive execution mechanism such as the driving motor 6, the opening and closing action of the main valve core 71 is rapid, thereby causing the switching process of the system working pressure from high pressure to low pressure (or vice versa) to be almost step-like. Such instantaneous change of pressure will form a large hydraulic impact on the driving motor 6, even causing problems such as hydraulic pipeline leakage, thereby shortening the service life of the hydraulic system of the excavator and the whole machine, which needs to be improved. SUMMARY

[0005] In order to reduce the damage to the driving motor, the present application provides a direct-acting buffer electromagnetic valve and a hydraulic system.

[0006] In a first aspect, the direct-acting buffer electromagnetic valve provided by the present application adopts the following technical scheme: The application discloses a direct-acting buffer electromagnetic valve, which comprises an electromagnetic valve body, wherein the electromagnetic valve body comprises a sleeve, a valve core and a push rod; one end of the sleeve is provided with an opening and forms a liquid outlet; the sleeve is provided with an installation groove in communication with the liquid outlet; the outer wall of the sleeve is provided with a liquid inlet in communication with the installation groove; the valve core is slidably arranged in the installation groove; one end of the valve core is provided with a communication groove in communication with the liquid outlet; the side wall of the valve core is provided with a communication hole in communication with the liquid inlet. The sleeve is provided with a pressure feedback cavity in communication with the sliding groove through a connecting groove; the push rod is slidably arranged in the pressure feedback cavity; one end of the push rod is connected with the valve core through the connecting groove; the sleeve is provided with an electromagnetic assembly for driving the push rod to slide; the valve core is provided with a first feedback channel in communication with the communication groove; and the push rod is provided with a second feedback channel for connecting the pressure feedback cavity and the first feedback channel.

[0007] By adopting the technical scheme, the pressure feedback cavity is initially communicated with the communication groove (liquid return passage) through the feedback channel, which ensures that the pressure before and after the valve core is balanced before the valve core is started, and facilitates the initial movement of the electromagnetic assembly by overcoming the static friction.

[0008] When the valve core moves to preliminarily communicate the communication hole with the high-pressure liquid inlet, the high-pressure oil enters the communication groove and then enters the pressure feedback cavity through the feedback channel; in the process that the high-pressure oil enters the feedback channel, the high-pressure oil abuts against the end wall of the feedback channel away from the communication groove, thereby increasing the sliding resistance of the valve core in the sliding groove and slowing down the moving speed of the valve core.

[0009] With the pressure feedback cavity being filled and pressurized, the accumulated hydraulic oil drives the valve core to move to arrange the liquid inlet opposite to the communication hole, that is, the electromagnetic valve body is in an open state; in this way, the moving speed of the valve core is slowed down, thereby realizing the buffer effect of smooth opening or closing, making the start and stop of the motor more gentle, improving the operation reliability and stability of the whole system, and further improving the service life of the excavator.

[0010] Optionally, the outer peripheral wall is provided with an annular groove, and the communication holes are arranged in groups, and all the communication holes are arranged in the annular groove.

[0011] By adopting the technical scheme, when the valve core moves to locally communicate the annular groove region with the liquid inlet, the high-pressure oil can fill the whole annular groove, thereby providing a common source with uniform and stable pressure for all the communication holes, so as to ensure that the high-pressure oil can be injected into the pressure feedback cavity through the multiple groups of communication holes; meanwhile, the annular groove can buffer the speed of the high-pressure oil entering the communication groove, so that the high-pressure oil can enter the pressure feedback cavity smoothly.

[0012] Optionally, the inner diameter of the communication hole is smaller than the inner diameter of the liquid inlet.

[0013] By adopting the technical scheme, high-pressure oil can fill the annular groove during the process of entering the communication groove through the connecting hole, so that the force of the high-pressure oil on the valve core is balanced, and the risk of uneven filling causing lateral wear or jamming of the valve core is prevented.

[0014] Optionally, the two adjacent communication holes are misaligned.

[0015] By adopting the technical scheme, the shunting process of high-pressure oil to the pressure feedback chamber can be continuous and smooth.

[0016] Optionally, the valve core comprises a sliding seat and a sliding sleeve, the sliding seat is slidingly installed in the sliding groove, and the communication groove and the first feedback channel are both arranged in the sliding seat; the sliding sleeve is slidingly installed in the communication groove. The communication hole comprises a first hole arranged in the sliding seat and a second hole arranged in the sliding sleeve, the first hole and the second hole are completely communicated in a first state, and the first hole and the second hole are partially communicated in a second state; the sleeve is provided with a switching assembly for switching the first state and the second state of the valve core.

[0017] By adopting the technical scheme, the switching assembly keeps the valve core in the second state (partially communicated), at this time, a narrow throttling orifice is formed between the first hole and the second hole; during the opening process of the electromagnetic valve, small-flow oil enters the communication groove smoothly and is injected into the pressure feedback chamber through the feedback channel, so that the pressure in the chamber is slowly established, thereby avoiding the instantaneous hydraulic impact of high-pressure oil on the valve core and the push rod, reducing the damage of the valve core, and further reducing the moving speed of the valve core.

[0018] During this process, the gradually rising oil pressure in the pressure feedback chamber acts on the effective area of the sliding sleeve, generating an auxiliary thrust in the same direction as the initial electromagnetic force, and the sliding sleeve starts to produce a smooth and controlled displacement relative to the sliding seat. As the communication area of the first hole and the second hole gradually increases, the oil inflow also increases smoothly, and the system pressure rises without impact until the two holes are completely aligned (reach the first state), realizing full-flow passage.

[0019] Optionally, the switching assembly comprises a first air bag and a second air bag, a first mounting block is mounted on the inner wall of the sliding groove, a first mounting groove is arranged on the outer wall of the sliding seat for the sliding of the first mounting block, and the first air bag is mounted between the first mounting block and the first mounting groove. A second mounting block is arranged on the outer wall of the sliding sleeve, a second mounting groove is arranged on the sliding seat for the sliding of the second mounting block, and the second air bag is mounted between the second mounting block and the second mounting groove; the first air bag and the second air bag are communicated; when the first air bag is in an inflated state, the valve core is in the second state.

[0020] By adopting the technical scheme, when the first air bag is in the inflated state, the sliding seat pushes the sliding sleeve to keep a specific relative position, thereby stably locking the valve core in the second state. During the opening process of the electromagnetic valve body, the first mounting block extrudes the first air bag, and the gas in the first air bag is extruded into the second air bag, so that the second air bag is in the inflated state, thereby enabling the valve core to switch to the first state.

[0021] Optionally, a first spring is arranged between the sliding seat and the sliding sleeve, and an elastic force of the first spring is used to enable the valve core to be in the second state.

[0022] By adopting the technical scheme, when the electromagnetic valve body is in the closed state, the elastic force of the first spring can enable the electromagnetic valve body to keep the second state.

[0023] Optionally, a limiting plate is slidingly arranged on an inner wall of the first mounting groove, and the limiting plate is connected to a side of the first air bag close to the first mounting block; when the valve core is in the first state, a gap exists between the limiting plate and the first mounting block.

[0024] By adopting the technical scheme, when the electromagnetic valve is powered on and the valve core starts to start from the fully closed position, due to the gap, the sliding seat will first move alone, and the first mounting block will not immediately contact the limiting plate at this stage, so that the first air bag or the first spring is not compressed temporarily, and the sliding sleeve keeps the original relative position with the sliding seat and does not slide relatively.

[0025] Only when the first hole of the sliding seat is initially connected to the liquid inlet, the first mounting block will abut against the limiting plate, and thereafter the first mounting block starts to extrude the first air bag, thereby triggering the sliding sleeve to start to move relatively, and starting the switching process from the second state to the first state.

[0026] Optionally, a buffer ring groove is arranged on an outer wall of the sliding sleeve, and the buffer ring groove is connected to the first hole when the valve core is in the second state.

[0027] By adopting the technical scheme, the impact force of the high-pressure oil entering the first hole can be further buffered, and the high-pressure oil can enter the communication groove smoothly.

[0028] In a second aspect, the application provides a hydraulic system.

[0029] The hydraulic system comprises the direct-acting buffering electromagnetic valve, a first conveying pipeline, a second conveying pipeline and a driving motor, one end of the first conveying pipeline is used for being connected with a feeding device, the other end of the first conveying pipeline is provided with two first pipelines, and the two first pipelines are respectively connected with a liquid inlet and the driving motor in communication; one end of the second conveying pipeline is used for being connected with a collecting device, the other end of the second conveying pipeline is provided with two second pipelines, and the two second pipelines are respectively connected with a liquid outlet and the driving motor in communication.

[0030] By adopting the technical scheme, in the process that the high-pressure oil enters the feedback channel, the high-pressure oil abuts against the end wall of the feedback channel far away from the communication groove, thereby increasing the sliding resistance of the valve core in the sliding groove and slowing down the moving speed of the valve core; the buffering effect of smooth opening or closing is realized, the start and stop of the motor are more gentle, and the operation reliability and stability of the whole system are improved.

[0031] In summary, the present application has at least one of the following beneficial technical effects: 1. When the valve core moves to preliminarily connect the communication hole with the high-pressure liquid inlet, the high-pressure oil enters the communication groove and enters the pressure feedback cavity through the feedback channel; in the process that the high-pressure oil enters the feedback channel, the high-pressure oil abuts against the end wall of the feedback channel far away from the communication groove, thereby increasing the sliding resistance of the valve core in the sliding groove and slowing down the moving speed of the valve core; the moving speed of the valve core is slowed down, thereby realizing the buffering effect of smooth opening or closing; the start and stop of the motor are more gentle, the operation reliability and stability of the whole system are improved, and the service life of the excavator is improved. 2. By setting the valve core as a sliding seat and a sliding sleeve, in the process that the electromagnetic valve is opened, small-flow oil enters the communication groove smoothly and is injected into the pressure feedback cavity through the feedback channel, so that the pressure in the cavity is slowly established, thereby avoiding the instantaneous hydraulic impact of the high-pressure oil on the valve core and the push rod. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 is a structural schematic view of the background art; Figure 2 is a partial sectional view of embodiment 1; Figure 3 is a partial sectional view of embodiment 1; Figure 2 is a partial enlarged view of a at Figure 4 is a partial enlarged view of b at Figure 2 Figure 5 is a partial sectional view of embodiment 2; Figure 6 is a partial enlarged view of c at Figure 5 Figure 7 is a structural schematic view of the valve core of embodiment 2;​​ Figure 8 is a flow chart of Example 3.

[0033] Reference signs: 1, sleeve; 11, mounting base; 111, pressure feedback cavity; 12, partition plate; 121, connecting groove; 122, partition ring; 13, connecting sleeve; 131, liquid outlet; 132, liquid inlet; 133, sliding groove; 14, second spring; 15, first mounting block; 16, movable rod; 2, valve core; 21, communication groove; 22, guide groove; 23, annular groove; 24, communication hole; 241, first hole; 242, second hole; 25, annular pressure equalizing groove; 26, first feedback channel; 27, sliding seat; 271, first mounting groove; 272, second mounting groove; 273, limiting groove; 274, limiting plate; 275, reset groove; 28, sliding sleeve; 281, second mounting block; 282, reset block; 283, first spring; 3, electromagnetic assembly; 31, third spring; 32, coil; 4, push rod; 41, mounting ring; 42, second feedback channel; 5, switching assembly; 51, first air bag; 52, second air bag; 6, drive motor; 61, first conveying pipeline; 611, first pipeline; 62, second conveying pipeline; 621, second pipeline; 7, valve body; 71, main valve core; 72, pilot valve core; 73, throttling channel; 75, oil drain channel; 76, control cavity. DETAILED DESCRIPTION

[0034] The following will be described in detail below with reference to the accompanying drawings. Figures 1-8 The application is further described in detail. Example 1:

[0035] The application discloses a direct-acting buffer electromagnetic valve.

[0036] With reference to Figure 2 and Figure 3 A direct-acting buffer electromagnetic valve, comprising an electromagnetic valve body, the electromagnetic valve body comprising a sleeve 1, a valve core 2, an electromagnetic assembly 3 and a push rod 4, the sleeve 1 is the main structure of the electromagnetic valve, which provides installation space and protection for other components. The material of the sleeve 1 can be selected from high-strength metal materials such as stainless steel and aluminum alloy to ensure that it has sufficient strength and corrosion resistance.

[0037] The sleeve 1 comprises a mounting base 11, a partition plate 12 and a connecting sleeve 13 mounted on one side of the mounting base 11, and the mounting base 11 is provided with a pressure feedback cavity 111 on one side; the connecting sleeve 13 is inserted into the side of the mounting base 11 with the pressure feedback cavity 111 and fixed thereto, and the fixing mode can be welding or connecting by bolts.

[0038] With reference to Figure 2In the embodiment, the partition plate 12 is installed in the pressure feedback cavity 111, the second spring 14 is arranged between the partition plate 12 and the mounting base 11, the two ends of the second spring 14 are connected with the inner wall of the pressure feedback cavity 111 and the partition plate 12 respectively, and the elastic force of the first spring 283 is used to abut the partition plate 12 against the side of the connecting sleeve 13 close to the pressure feedback cavity 111, so that the assembly of the sleeve 1 is completed.

[0039] When the sleeve 1 is assembled, the two ends of the first spring 283 are connected with the partition plate 12 and the inner wall of the pressure feedback cavity 111 respectively, then the connecting sleeve 13 is inserted into the mounting base 11 having the pressure feedback cavity 111 and is fixed therewith, and the partition plate 12 is abutted against one end of the connecting sleeve 13 under the elastic force of the first spring 283. The mounting mode is more convenient and improves the assembly efficiency.

[0040] The connecting sleeve 13 has a liquid outlet 131 at one end, which is used to discharge liquid. In the embodiment, the liquid outlet 131 is circular in shape. The liquid inlet 132 is arranged on the side wall of the sleeve 1 and is used to introduce liquid. The size and shape of the liquid inlet 132 can be designed according to actual needs. In the embodiment, a plurality of groups of liquid inlets 132 are arranged on the outer peripheral wall of the connecting sleeve 13 in a circumferential direction.

[0041] The liquid outlet 131 is close to the inner wall of the side of the mounting base 11, and the sliding groove 133 is arranged in the inner wall. The valve core 2 is slidably installed in the sliding groove 133. The partition plate 12 is provided with a connecting groove 121 for connecting the pressure feedback cavity 111 and the sliding groove 133. In the embodiment, the push rod 4 is integrally formed with one end of the valve core 2. The movable rod 16 is movably installed in the mounting base 11. The end of the push rod 4 away from the valve core 2 is connected with the movable rod 16 through the connecting groove 121.

[0042] Referring to Figure 3 The outer diameter of the push rod 4 is smaller than the inner diameter of the connecting groove 121, so that the sliding groove 133 and the pressure feedback cavity 111 are in communication, so as to facilitate the high-pressure oil to enter between the inner wall of the sliding groove 133 and the valve core 2. In order to further facilitate the high-pressure oil to enter between the inner wall of the sliding groove 133 and the valve core 2, the partition plate 12 is provided with a partition ring 122 for abutting against the valve core 2.

[0043] The electromagnetic assembly 3 includes a third spring 31 and a coil 32. The coil 32 is installed on the outer side of the mounting base 11. The second spring 14 is sleeved on the outer wall of the push rod 4. The outer wall of the push rod 4 is provided with a mounting ring 41. The two ends of the second spring 14 are connected with the mounting ring 41 and the partition plate 12 respectively. The elastic force of the second spring 14 is used to drive the valve core 2 to move towards the side of the sliding groove 133, so that the side wall of the valve core 2 covers the liquid inlet 132, that is, the electromagnetic valve body is in a closed state.

[0044] When the coil 32 is energized, a magnetic field is generated, thereby repelling the push rod 4, realizing the sliding of the push rod 4, moving the valve core 2 to the side of the liquid outlet 131, thereby opening the electromagnetic valve. In the power-off closing process, the elastic force stored by the second spring 14 is released, moving the valve core 2 to the side of the sliding groove 133, thereby closing the electromagnetic valve.

[0045] Referring to Figure 4 , the valve core 2 is provided with a communication groove 21 at one end close to the liquid outlet 131, the communication groove 21 is used to connect the liquid inlet 132 and the liquid outlet 131; the communication groove 21 is provided with a first feedback channel 26, the push rod 4 is provided with a second feedback channel 42 connected with the first feedback channel 26, the second feedback channel 42 is used to connect the first feedback channel 26 and the pressure feedback cavity 111.

[0046] And in order to be able to guide the flow of oil, avoid the generation of severe vortex or flow separation at the inlet, the communication groove 21 is connected with the second feedback channel 42 through the guide groove 22, the inner diameter of the guide groove 22 gradually decreases from the side close to the second feedback channel 42 to the side of the second feedback channel 42.

[0047] The outer wall of the valve core 2 is provided with an annular groove 23, the annular groove 23 is provided with a plurality of communication holes 24 connected with the communication groove 21, all the communication holes 24 are arranged in a circumferential direction interval along the outer wall of the valve core 2, and the adjacent two communication holes 24 are arranged in a staggered manner. When the electromagnetic valve body is in a closed state, the communication hole 24 is located at the side close to the pressure feedback cavity 111 of the liquid inlet 132; the annular groove 23 provides a common source of uniform and stable pressure for high-pressure oil, ensuring that high-pressure oil can be injected into the pressure feedback cavity 111 through multiple groups of communication holes 24.

[0048] In this embodiment, the inner diameter of the communication hole 24 is smaller than the inner diameter of the liquid inlet 132, which can ensure that the high-pressure oil can fill the annular groove 23 while entering the communication groove 21 through the communication hole 24, so that the force of the high-pressure oil on the valve core 2 is balanced, preventing the valve core 2 from being laterally worn.

[0049] The outer wall of the valve core 2 is provided with a plurality of annular pressure equalizing grooves 25, which can allow oil to enter the small gap between the inner wall of the sleeve 1 and the valve core 2 through the liquid inlet 132 when the electromagnetic valve is in a closed state, realizing the effects of lubrication, pressure equalization and anti-stuck.

[0050] The implementation principle of the embodiment 1 of the present application is: When the valve core 2 moves to preliminarily connect the communication hole 24 and the high-pressure liquid inlet 132, the high-pressure oil enters the communication groove 21 and enters the pressure feedback cavity 111 through the feedback channel; in the process of high-pressure oil entering the feedback channel, the high-pressure oil will abut against the end wall of the feedback channel away from the communication groove 21, thereby increasing the resistance of the valve core 2 sliding in the sliding groove 133, slowing down the moving speed of the valve core 2.

[0051] And with the pressure feedback cavity 111 is filled and pressurized, where the accumulated hydraulic oil will drive the spool 2 to move to make the liquid inlet 132 and the communication hole 24 is set opposite, that is, the electromagnetic valve body is open state; This way can delay the moving speed of the spool 2, so as to realize the smooth opening or closing of the buffer effect. Make the start and stop of the drive motor 6 more soft, reduce the hydraulic pipeline leakage and other problems, improve the service life of the excavator. Embodiment 2:

[0052] The embodiment of the application discloses a direct-acting buffer electromagnetic valve.

[0053] Referring to Figure 5 and Figure 6 , the difference between the embodiment 2 and the embodiment 1 is that the spool 2 comprises a sliding seat 27 and a sliding sleeve 28, at least two first mounting blocks 15 are mounted on the inner wall of the sliding groove 133, and the two first mounting blocks 15 are arranged at intervals along the inner peripheral wall of the sliding groove 133; the outer wall of the sliding seat 27 is provided with a first mounting groove 271 for sliding of the first mounting block 15, and the extension direction of the first mounting groove 271 is arranged in the same direction as the axis direction of the sliding groove 133; the communication groove 21, the guide groove 22 and the first feedback hole are all arranged on the sliding seat 27.

[0054] Referring to Figure 7 , the outer wall of the sliding sleeve 28 is provided with at least two second mounting blocks 281, the inner wall of the communication groove 21 is provided with a second mounting groove 272 for sliding of the second mounting block 281, and one end of the second mounting groove 272 is in communication with the outer wall of the sliding seat 27. The communication hole 24 comprises a first hole 241 arranged on the sliding seat 27 and a second hole 242 arranged on the sliding sleeve 28, the first hole 241 and the second hole 242 are in full communication in a first state, and the first hole 241 and the second hole 242 are in partial communication in a second state; the sliding seat 27 is provided with a switching assembly 5 for switching between the first state and the second state.

[0055] Referring to Figure 6 and Figure 7 , the switching assembly 5 comprises a first air bag 51 and a second air bag 52, the first air bag 51 is mounted between the first mounting block 15 and the inner wall of the first mounting groove 271, the second air bag 52 is mounted between the second mounting block 281 and the inner wall of the second mounting groove 272, and the first air bag 51 and the second air bag 52 are in communication through an air pipe; when the spool 2 is in the second state, the first air bag 51 is in an inflated state.

[0056] In the embodiment, a limiting groove 273 is arranged on the inner wall of the first mounting groove 271, the length of the limiting groove 273 is less than the length of the first mounting groove 271, and the first mounting groove 271 is provided with a limiting plate 274 in sliding connection with the limiting groove 273; when the limiting plate 274 is connected to the side of the first air bag 51 close to the first mounting block 15; when the valve core 2 is in the first state, the limiting plate 274 is located at one end of the limiting groove 273, and a gap is formed between the limiting plate 274 and the first mounting block 15.

[0057] The outer wall of the sliding sleeve 28 is provided with a reset block 282, the inner wall of the connecting groove 121 is provided with a reset groove 275 for the sliding of the reset block 282, and the connecting groove 121 is in communication with the outer wall of the sliding seat 27; a first spring 283 is arranged between the reset block 282 and the inner wall of the reset groove 275, and the elastic force of the first spring 283 is used to keep the valve core 2 in the second state.

[0058] In other embodiments, the outer wall of the sliding sleeve 28 is provided with a buffer ring groove, and when the valve core 2 is in the first state, the buffer ring groove is in communication with the first hole 241.

[0059] The implementation principle of the embodiment 2 of the application is as follows: The switching assembly 5 keeps the valve core 2 in the second state (partly connected), at this time, the first hole 241 and the second hole 242 form a narrow throttling orifice; in the opening process of the electromagnetic valve, the small-flow oil enters the connecting groove 21 smoothly, and is injected into the pressure feedback chamber 111 through the feedback channel, so that the pressure in the chamber is slowly established, thereby avoiding the instantaneous hydraulic impact of the high-pressure oil on the valve core 2 and the push rod 4.

[0060] In this process, the gradually rising oil pressure in the pressure feedback chamber 111 acts on the effective area of the sliding sleeve 28, generating an auxiliary thrust in the same direction as the initial electromagnetic force, and the sliding sleeve 28 starts to produce a smooth and controlled displacement relative to the sliding seat 27. As the connecting area of the first hole 241 and the second hole 242 gradually increases, the oil inlet flow also increases smoothly, and the system pressure rises without impact until the two holes are completely aligned to realize full-flow passage. Embodiment 3:

[0061] In a second aspect, the application discloses a hydraulic system.

[0062] Reference Figure 8A hydraulic system comprises a first conveying pipe 61, a second conveying pipe 62, a driving motor 6 and the direct-acting buffer electromagnetic valve of the embodiment 1. One end of the first conveying pipe 61 is used for being connected with a feeding device, and the other end of the first conveying pipe is provided with two first pipes 611 which are respectively connected with the liquid inlet 132 and the driving motor 6. One end of the second conveying pipe 62 is used for being connected with a receiving device, and the other end of the second conveying pipe is provided with two second pipes 621 which are respectively connected with the liquid outlet 131 and the driving motor 6.

[0063] The principle of the embodiment of the present application is that, in the process that the high-pressure oil enters the feedback channel, the high-pressure oil abuts against the end wall of the feedback channel far from the communication groove 21, thereby increasing the resistance of the valve core 2 to slide in the sliding groove 133 and slowing down the moving speed of the valve core 2. The smooth opening or closing buffer effect is realized, the start and stop of the motor are more gentle, the operation reliability and stability of the whole system are maintained, and the service life of the excavator is improved.

[0064] The above is the preferred embodiment of the present application, which does not limit the protection scope of the present application, so that: any equivalent change made according to the structure, shape, principle of the present application should be covered in the protection scope of the present application.

Claims

1. A direct-acting buffer solenoid valve, characterized in that: The device includes a solenoid valve body, which includes a sleeve (1), a valve core (2), and a push rod (4). One end of the sleeve (1) has an opening and forms a liquid outlet (131). The sleeve (1) has an installation groove that communicates with the liquid outlet (131). The outer wall of the sleeve (1) has an inlet (132) that communicates with the installation groove. The valve core (2) is slidably installed in the installation groove. One end of the valve core (2) has a connecting groove (21) for communicating with the liquid outlet (131). The side wall of the valve core (2) has a connecting hole (24) for communicating with the liquid inlet (132). The sleeve (1) is provided with a pressure feedback chamber (111), which is connected to the sliding groove (133) through the connecting groove (121); the push rod (4) is slidably installed in the pressure feedback chamber (111), and one end of the push rod (4) passes through the connecting groove (121) and is connected to the valve core (2); the sleeve (1) is provided with an electromagnetic component (3) for driving the push rod (4) to slide; the valve core (2) is provided with a first feedback channel (26) connected by a connecting groove (21), and the push rod (4) is provided with a second feedback channel (42) for connecting the pressure feedback chamber (111) and the first feedback channel (26).

2. The direct-acting buffer solenoid valve according to claim 1, characterized in that: The valve core (2) has an annular groove (23) on its outer peripheral wall, and multiple sets of connecting holes (24) are provided, all of which are located in the annular groove (23).

3. A direct-acting buffer solenoid valve according to claim 2, characterized in that: The inner diameter of the connecting hole (24) is smaller than the inner diameter of the liquid inlet (132).

4. A direct-acting buffer solenoid valve according to claim 2, characterized in that: The two adjacent connecting holes (24) are staggered.

5. A direct-acting buffer solenoid valve according to claim 1, characterized in that: The valve core (2) includes a sliding seat (27) and a sliding sleeve (28). The sliding seat (27) is slidably installed in the sliding groove (133). The connecting groove (21) and the first feedback channel (26) are both opened in the sliding seat (27). The sliding sleeve (28) is slidably installed in the connecting groove (21). The connecting hole (24) includes a first hole (241) opened in the sliding seat (27) and a second hole (242) opened in the sliding sleeve (28). The first hole (241) and the second hole (242) are fully connected in a first state, and the first hole (241) and the second hole (242) are partially connected in a second state. The sleeve (1) is provided with a switching component (5) for switching the first state and the second state of the valve core (2).

6. A direct-acting buffer solenoid valve according to claim 5: the switching assembly (5) includes a first airbag (51) and a second airbag (52), a first mounting block (15) is installed on the inner wall of the sliding groove (133), a first mounting groove (271) for sliding of the first mounting block (15) is opened on the outer wall of the sliding seat (27), and the first airbag (51) is installed between the first mounting block (15) and the first mounting groove (271); The outer wall of the sliding sleeve (28) is provided with a second mounting block (281), and the sliding seat (27) is provided with a second mounting groove (272) for the second mounting block (281) to slide. The second airbag (52) is installed between the second mounting block (281) and the second mounting groove (272). The first airbag (51) is connected to the second airbag (52). When the first airbag (51) is in an inflated state, the valve core (2) is in a second state.

7. A direct-acting buffer solenoid valve according to claim 6: a first spring (283) is provided between the sliding seat (27) and the sliding sleeve (28), and the elastic force of the first spring (283) is used to put the valve core (2) in a second state.

8. A direct-acting buffer solenoid valve according to claim 6: a limiting plate (274) is slidably installed on the inner wall of the first mounting groove (271), and the limiting plate (274) is connected to the side of the first airbag (51) near the first mounting block (15); when the valve core (2) is in the first state, there is a gap between the limiting plate (274) and the first mounting block (15).

9. A direct-acting buffer solenoid valve according to claim 6, characterized in that: The outer wall of the sliding sleeve (28) is provided with a buffer ring groove. When the valve core (2) is in the second state, the buffer ring groove is connected to the first hole (241).

10. A hydraulic system, characterized in that: The device includes a first conveying pipe (61), a second conveying pipe (62), a drive motor (6), and a direct-acting buffer solenoid valve as described in any one of claims 1-9. One end of the first conveying pipe (61) is connected to a feeding device, and the other end of the first conveying pipe (61) is provided with two first pipes (611), which are respectively connected to the liquid inlet (132) and the drive motor (6). One end of the second conveying pipe (62) is connected to a receiving device, and the other end of the second conveying pipe (62) is provided with two second pipes (621), which are respectively connected to the liquid outlet (131) and the drive motor (6).

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