Direct-acting cushioning electromagnetic valve and hydraulic system

Abstract

This application relates to the field of solenoid valve technology and provides a direct-acting buffer solenoid valve, including a solenoid valve body. The solenoid valve body includes a sleeve, a valve core, and a push rod. The valve core is slidably installed in a mounting groove, and one end of the valve core is provided with a communicating groove for connecting to the outlet. A communicating hole is opened on the side wall of the valve core for connecting to the inlet. A pressure feedback chamber is provided in the sleeve, and the pressure feedback chamber is connected to the sliding groove through a connecting groove. The push rod is slidably installed in the pressure feedback chamber, and one end of the push rod passes through the connecting groove and connects to the valve core. The sleeve is provided with an electromagnetic component for driving the push rod to slide. The valve core has a first feedback channel connected by the communicating groove, and the push rod has a second feedback channel for connecting the pressure feedback chamber and the first feedback channel. This direct-acting buffer solenoid valve of this application aims to reduce the damage to the drive motor and improve the service life of the excavator. This application also provides a hydraulic system.

Description

Technical Field

[0001] This application relates to the field of solenoid valve technology, and in particular to a direct-acting buffer solenoid valve and hydraulic system. Background Technology

[0002] As the core power and control unit of an excavator, the hydraulic system's performance directly affects the machine's operating efficiency, operability, and reliability. In excavator hydraulic systems, solenoid valves are widely used to control the starting, stopping, and reversing of actuators such as the swing motor, travel motor, and cylinders of various working devices (e.g., boom, stick, bucket). To achieve control of high-flow-rate oil circuits, pilot-operated solenoid valves are commonly used in current excavator hydraulic systems. (Refer to...) Figure 1 The existing pilot-operated solenoid valve includes a valve body 7, a main valve core 71, a pilot valve core 72, and an electromagnetic drive component. The valve body 7 has an outlet 131 and an inlet 132. The main valve core 71 is slidably disposed within the main valve chamber of the valve body 7. One end of the main valve core 71 has a closed control chamber 76, which is normally connected to the inlet 132 through a throttling channel 73 located in the valve body 7 or the main valve core 71. The pilot valve core 72 is usually a small slide valve or cone valve located in the control chamber 76, and is directly driven by an electromagnet. The pilot valve core 72 controls the opening and closing of an oil drain channel 75, which connects the control chamber 76 to the outlet 131.

[0003] When the excavator needs to perform compound actions or drive components with high inertia (such as starting the slewing platform), the controller sends a command to energize the electromagnet, which actuates the pilot valve core 72, rapidly opening the drain passage 75. The high-pressure fluid in the control chamber 76 is then quickly released through the drain passage 75 to the outlet 131, causing a sharp drop in pressure within the control chamber 76. At this time, the other end of the main valve core 71 still bears the system pressure; this pressure difference creates a huge net thrust, overcoming the spring force and causing the main valve core 71 to open rapidly within milliseconds, completing the oil circuit switching.

[0004] When used to control actuators such as the drive motor 6 that are sensitive to pressure changes, the rapid opening and closing of its main valve core 71 causes the system working pressure to switch from high pressure to low pressure (or vice versa) in a near-step manner. This instantaneous pressure change can cause a huge hydraulic shock to the drive motor 6, and may even lead to problems such as hydraulic pipeline leakage, thereby shortening the service life of the excavator's hydraulic system and the entire machine, which needs to be improved. Summary of the Invention

[0005] In order to reduce the occurrence of damage to the drive motor, this application provides a direct-acting buffer solenoid valve and a hydraulic system.

[0006] Firstly, the direct-acting buffer solenoid valve provided in this application adopts the following technical solution:

[0007] A direct-acting buffer solenoid valve includes a solenoid valve body, which includes a sleeve, a valve core, and a push rod. One end of the sleeve has an opening forming a liquid outlet, and the sleeve has an installation groove communicating with the liquid outlet. The outer wall of the sleeve has an inlet communicating with the installation groove. The valve core is slidably installed in the installation groove, and one end of the valve core has a connecting groove for communicating with the liquid outlet. The side wall of the valve core has a connecting hole for communicating with the liquid inlet.

[0008] The sleeve is provided with a pressure feedback chamber, which is connected to a sliding groove through a connecting groove. The push rod is slidably installed in the pressure feedback chamber, and one end of the push rod passes through the connecting groove and is connected to the valve core. The sleeve is provided with an electromagnetic component for driving the push rod to slide. The valve core has a first feedback channel connected by a connecting groove, and the push rod has a second feedback channel for connecting the pressure feedback chamber and the first feedback channel.

[0009] By adopting the above technical solution, the pressure feedback chamber is initially connected to the connecting groove (return fluid passage) through the feedback channel, which ensures that the pressure before and after the valve core is started is balanced, which makes it easier for the electromagnetic component to overcome static friction and move it initially.

[0010] When the valve core moves to initially connect the connecting hole with the high-pressure inlet, the high-pressure oil enters the connecting groove and then enters the pressure feedback chamber through the feedback channel. During the process of the high-pressure oil entering the feedback channel, it will abut against the end wall of the feedback channel away from the connecting groove, thereby increasing the resistance of the valve core sliding in the sliding groove and slowing down the movement speed of the valve core.

[0011] As the pressure feedback chamber is filled and pressurized, the accumulated hydraulic oil drives the valve core to move so that the inlet port is aligned with the connecting hole, i.e., the solenoid valve body is in the open state. This method slows down the movement speed of the valve core, thus achieving a buffering effect for smooth opening or closing. This makes the motor start and stop more gently, improves the operational reliability and stability of the entire system, and consequently extends the service life of the excavator.

[0012] Optionally, the outer peripheral wall is provided with an annular groove, and multiple sets of connecting holes are provided, with all connecting holes located in the annular groove.

[0013] By adopting the above technical solution, when the valve core moves to partially connect the annular groove area with the inlet, the high-pressure oil can fill the entire annular groove, providing a common source of uniform and stable pressure for all connecting holes, thus ensuring that the high-pressure oil can be injected into the pressure feedback chamber through multiple sets of connecting holes; at the same time, the setting of the annular groove can buffer the speed at which the high-pressure oil enters the connecting groove, so that the high-pressure oil enters the pressure feedback chamber smoothly.

[0014] Optionally, the inner diameter of the connecting hole is smaller than the inner diameter of the liquid inlet.

[0015] By adopting the above technical solution, the high-pressure oil can fill the annular groove during the process of entering the connecting groove through the connecting hole, so that the force of the high-pressure oil on the valve core is balanced, and the risk of lateral wear or jamming of the valve core caused by uneven filling is prevented.

[0016] Optionally, two adjacent connecting holes can be staggered.

[0017] By adopting the above technical solution, the process of diverting high-pressure oil to the pressure feedback chamber can be made continuous and stable.

[0018] Optionally, the valve core includes a sliding seat and a sliding sleeve, the sliding seat being slidably installed in a sliding groove, and the connecting groove and the first feedback channel being both opened in the sliding seat; the sliding sleeve being slidably installed in the connecting groove;

[0019] The connecting hole includes a first hole in the sliding seat and a second hole in the sliding sleeve. The first hole and the second hole are fully connected in a first state, and the first hole and the second hole are partially connected in a second state. The sleeve is provided with a switching component for switching the first state and the second state of the valve core.

[0020] By adopting the above technical solution, the switching component keeps the valve core in the second state (partially connected). At this time, the narrow throttling orifice formed by the first and second holes; during the opening process of the solenoid valve, a small flow of oil slowly enters the connecting groove and is injected into the pressure feedback chamber through the feedback channel, so that the pressure in the chamber can be slowly built up, thereby avoiding the instantaneous hydraulic shock of high pressure oil to the valve core and push rod, reducing the possibility of damage to the valve core, and further slowing down the movement speed of the valve core.

[0021] During this process, the gradually increasing 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. The sliding sleeve begins to produce a smooth and controlled displacement relative to the sliding seat. As the connecting area between the first and second holes gradually increases, the oil flow rate also increases smoothly, allowing the system pressure to rise without impact until the two holes are completely aligned (reaching the first state), achieving full flow passage.

[0022] Optionally, the switching component includes a first airbag and a second airbag, a first mounting block is installed on the inner wall of the sliding groove, a first mounting groove is opened on the outer wall of the sliding seat for the first mounting block to slide, and the first airbag is installed between the first mounting block and the first mounting groove.

[0023] The outer wall of the sliding sleeve is provided with a second mounting block, and the sliding seat is provided with a second mounting groove for the second mounting block to slide. The second airbag is installed between the second mounting block and the second mounting groove. The first airbag is connected to the second airbag. When the first airbag is inflated, the valve core is in the second state.

[0024] By adopting the above technical solution, when the first airbag is inflated, it pushes the sliding seat and the sliding sleeve to maintain a specific relative position, thereby stably locking the valve core in the second state. During the opening process of the solenoid valve body, the first mounting block squeezes the first airbag, forcing the gas in the first airbag into the second airbag, which then inflates, allowing the valve core to switch to the first state.

[0025] Optionally, a first spring is provided between the sliding seat and the sliding sleeve, and the spring force of the first spring is used to put the valve core in the second state.

[0026] By adopting the above technical solution, when the solenoid valve body is in the closed state, the elastic force of the first spring can keep the solenoid valve body in the second state.

[0027] Optionally, a limiting plate is slidably installed on the inner wall of the first mounting groove, and the limiting plate is connected to the side of the first airbag near the first mounting block; when the valve core is in the first state, there is a gap between the limiting plate and the first mounting block.

[0028] By adopting the above technical solution, when the solenoid valve is energized and the valve core starts to start from the fully closed position, due to the gap, the sliding seat will move independently first, and the first mounting block will not immediately contact the limiting plate at this stage. Therefore, the first airbag or the first spring is not compressed temporarily, and the sliding sleeve and the sliding seat maintain their original relative positions and do not slide relative to each other.

[0029] Only when the first hole of the sliding seat is initially connected to the liquid inlet will the first mounting block abut against the limiting plate. After that, the first mounting block begins to squeeze the first airbag, thereby triggering the sliding sleeve to begin relative movement and initiating the switching process from the second state to the first state.

[0030] Optionally, a buffer ring groove is provided on the outer wall of the sliding sleeve. When the valve core is in the second state, the buffer ring groove is connected to the first hole.

[0031] By adopting the above technical solution, the impact force of high-pressure oil entering the first hole can be further buffered, allowing the high-pressure oil to enter the connecting groove smoothly.

[0032] Secondly, this application provides a hydraulic system.

[0033] A hydraulic system includes the aforementioned direct-acting buffer solenoid valve, a first conveying pipe, a second conveying pipe, and a drive motor. One end of the first conveying pipe is connected to a feeding device, and the other end of the first conveying pipe is provided with two first pipes, which are respectively connected to an inlet and a drive motor. One end of the second conveying pipe is connected to a receiving device, and the other end of the second conveying pipe is provided with two second pipes, which are respectively connected to an outlet and a drive motor.

[0034] By adopting the above technical solution, during the process of high-pressure oil entering the feedback channel, it will abut against the end wall of the feedback channel away from the connecting groove, thereby increasing the resistance of the valve core sliding in the sliding groove and slowing down the movement speed of the valve core; achieving a buffering effect of smooth opening or closing, making the start and stop of the motor more gentle, and improving the operational reliability and stability of the entire system.

[0035] In summary, this application includes at least one of the following beneficial technical effects:

[0036] 1. When the valve core moves to initially connect the connecting hole with the high-pressure inlet, the high-pressure oil enters the connecting groove and then enters the pressure feedback chamber through the feedback channel. During the process of the high-pressure oil entering the feedback channel, it will abut against the end wall of the feedback channel away from the connecting groove, thereby increasing the resistance of the valve core sliding in the sliding groove and slowing down the movement speed of the valve core. This method can delay the movement speed of the valve core, thereby achieving a buffering effect of smooth opening or closing. This makes the start and stop of the motor smoother, improves the operational reliability and stability of the entire system, and extends the service life of the excavator.

[0037] 2. By setting the valve core as a sliding seat and sliding sleeve, when the solenoid valve is open, a small flow of oil slowly enters the connecting groove and is injected into the pressure feedback chamber through the feedback channel, so that the pressure in the chamber can be slowly built up, thereby avoiding the instantaneous hydraulic shock of high pressure oil to the valve core and push rod. Attached Figure Description

[0038] Figure 1 This is a structural diagram of the background technology;

[0039] Figure 2 This is a partial cross-sectional view of Embodiment 1;

[0040] Figure 3 yes Figure 2 A magnified view of a portion at point a;

[0041] Figure 4 yes Figure 2 A magnified view of a portion at point b;

[0042] Figure 5 This is a partial cross-sectional view of Embodiment 2;

[0043] Figure 6 yes Figure 5 A magnified view of a portion at point c;

[0044] Figure 7 This is a schematic diagram of the valve core structure in Example 2;

[0045] Figure 8 This is a flowchart of Example 3.

[0046] Explanation of reference numerals in the attached drawings: 1. Sleeve; 11. Mounting base; 111. Pressure feedback chamber; 12. Divider plate; 121. Connecting groove; 122. Divider 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. Connecting groove; 22. Guide groove; 23. Annular groove; 24. Connecting hole; 241. First hole; 242. Second hole; 25. Annular equalizing groove; 26. First feedback channel; 27. Sliding seat; 271. First mounting groove; 272. Second mounting groove; 273. Limiting 274. Positioning slot; 275. Reset slot; 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 airbag; 52. Second airbag; 6. Drive motor; 61. First delivery pipe; 611. First pipe; 62. Second delivery pipe; 621. Second pipe; 7. Valve body; 71. Main valve core; 72. Pilot valve core; 73. Throttling channel; 75. Oil drain channel; 76. Control chamber. Detailed Implementation

[0047] The following is in conjunction with the appendix Figures 1-8 This application will be described in further detail. Example 1:

[0048] This application discloses a direct-acting buffer solenoid valve.

[0049] Reference Figure 2 and Figure 3 A direct-acting buffer solenoid valve includes a solenoid valve body, which comprises a sleeve 1, a valve core 2, a solenoid assembly 3, and a push rod 4. The sleeve 1 is the main structure of the solenoid valve, providing installation space and protection for other components. The sleeve 1 can be made of high-strength metal materials, such as stainless steel or aluminum alloy, to ensure sufficient strength and corrosion resistance.

[0050] The sleeve 1 includes a mounting base 11, a partition plate 12, and a connecting sleeve 13 installed on one side of the mounting base 11. A pressure feedback chamber 111 is provided on one side of the mounting base 11. The connecting sleeve 13 is inserted into and fixed to the side of the mounting base 11 with the pressure feedback chamber 111. The fixing method can be welding or bolt connection.

[0051] Reference Figure 2 In this embodiment, the partition plate 12 is installed in the pressure feedback chamber 111. A second spring 14 is provided between the partition plate 12 and the mounting base 11. The two ends of the second spring 14 are respectively connected to the inner wall of the pressure feedback chamber 111 and the partition plate 12. The elastic force of the first spring 283 is used to make the partition plate 12 and the connecting sleeve 13 close to the side of the pressure feedback chamber 111 press tightly together, thereby completing the assembly of the sleeve 1.

[0052] When assembling the sleeve 1, first connect the two ends of the first spring 283 to the partition plate 12 and the inner wall of the pressure feedback chamber 111 respectively. Then, insert the connecting sleeve 13 into the mounting base 11 which has the pressure feedback chamber 111 and fix it thereto. Under the elastic force of the first spring 283, the partition plate 12 abuts against one end of the connecting sleeve 13. This installation method is more convenient and improves assembly efficiency.

[0053] One end of the connecting sleeve 13 has a liquid outlet 131 for discharging liquid. In this embodiment, the liquid outlet 131 is circular in shape. The liquid inlet 132 is provided on the side wall of the sleeve 1 for introducing liquid. The size and shape of the liquid inlet 132 can be designed according to actual needs. In this embodiment, multiple sets of liquid inlets 132 are provided, and all liquid inlets 132 are spaced apart circumferentially along the outer peripheral wall of the connecting sleeve 13.

[0054] A sliding groove 133 is provided on the inner wall of the outlet 131 near the mounting base 11. 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 chamber 111 and the sliding groove 133. In this embodiment, the push rod 4 is integrally formed with one end of the valve core 2. A movable rod 16 is movably installed in the mounting base 11. The end of the push rod 4 away from the valve core 2 passes through the connecting groove 121 and is connected to the movable rod 16.

[0055] Reference 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 chamber 111 are in a connected state, so that high pressure oil can enter between the inner wall of the sliding groove 133 and the valve core 2; and in order to further facilitate the entry of high pressure oil 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.

[0056] The electromagnetic component 3 includes a third spring 31 and a coil 32. The coil 32 is installed on the outside 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 to 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 toward one 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 the closed state.

[0057] When coil 32 is energized, it generates a magnetic field, which repels push rod 4, causing push rod 4 to slide and move valve core 2 toward the outlet 131, thereby opening the solenoid valve. During the de-energization closing process, the elastic force stored in the second spring 14 is released, causing valve core 2 to move toward the sliding groove 133, thereby closing the solenoid valve.

[0058] Reference Figure 4 The valve core 2 has a connecting groove 21 at one end near the liquid outlet 131, which is used to connect the liquid inlet 132 and the liquid outlet 131. The connecting groove 21 has a first feedback channel 26, and the push rod 4 has a second feedback channel 42 connected to the first feedback channel 26. The second feedback channel 42 is used to connect the first feedback channel 26 to the pressure feedback chamber 111.

[0059] In order to guide the flow of oil and avoid violent eddies or flow separation at the inlet, the connecting groove 21 is connected to the second feedback channel 42 through the guide groove 22. The inner diameter of the guide groove 22 gradually decreases on the side closer to the second feedback channel 42.

[0060] The outer wall of the valve core 2 has an annular groove 23, and the annular groove 23 has multiple connecting holes 24 that communicate with the connecting groove 21. All connecting holes 24 are spaced apart along the circumferential side of the outer wall of the valve core 2, and adjacent connecting holes 24 are staggered. When the solenoid valve body is in the closed state, the connecting holes 24 are located on the side of the inlet 132 near the pressure feedback chamber 111. The function of the annular groove 23 is to provide a common source of uniform and stable pressure for the high-pressure oil, ensuring that the high-pressure oil can be injected into the pressure feedback chamber 111 through multiple sets of connecting holes 24.

[0061] In this embodiment, the inner diameter of the connecting hole 24 is smaller than the inner diameter of the inlet 132. This ensures that the high-pressure oil can fill the annular groove 23 while entering the connecting groove 21 through the connecting hole 24, so that the force of the high-pressure oil on the valve core 2 is balanced and prevents the valve core 2 from experiencing lateral wear.

[0062] The outer wall of the valve core 2 is provided with multiple annular pressure equalizing grooves 25. When the solenoid valve is closed, oil can enter the tiny gap between the valve core 2 and the inner wall of the sleeve 1 through the inlet 132 to achieve the effects of lubrication, pressure equalization and anti-jamming.

[0063] The implementation principle of Embodiment 1 of this application is as follows:

[0064] When the valve core 2 moves to initially connect the connecting hole 24 with the high pressure inlet 132, the high pressure oil enters the connecting groove 21 and enters the pressure feedback chamber 111 through the feedback channel. During the process of the high pressure oil entering the feedback channel, it will abut against the end wall of the feedback channel away from the connecting groove 21, thereby increasing the resistance of the valve core 2 sliding in the sliding groove 133 and slowing down the movement speed of the valve core 2.

[0065] As the pressure feedback chamber 111 is filled and pressurized, the accumulated hydraulic oil drives the valve core 2 to move so that the inlet port 132 is aligned with the connecting hole 24, i.e., the solenoid valve body is in the open state. This method can slow down the movement speed of the valve core 2, thereby achieving a buffering effect for smooth opening or closing. This makes the start and stop of the drive motor 6 more gentle, reduces problems such as hydraulic pipeline leakage, and improves the service life of the excavator. Example 2:

[0066] This application discloses a direct-acting buffer solenoid valve.

[0067] Reference Figure 5 and Figure 6 The difference between Embodiment 2 and Embodiment 1 is that: the valve core 2 includes a sliding seat 27 and a sliding sleeve 28; at least two first mounting blocks 15 are installed on the inner wall of the sliding groove 133, and the two first mounting blocks 15 are spaced apart along the inner peripheral wall of the sliding groove 133; a first mounting groove 271 for the first mounting blocks 15 to slide is opened on the outer wall of the sliding seat 27, and the extension direction of the first mounting groove 271 is in the same direction as the axis of the sliding groove 133; the connecting groove 21, the guide groove 22 and the first feedback passage are all opened on the sliding seat 27.

[0068] Reference 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 connecting groove 21 is provided with a second mounting groove 272 for the second mounting blocks 281 to slide. One end of the second mounting groove 272 is connected to the outer wall of the sliding seat 27. 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 completely connected in the first state, and the first hole 241 and the second hole 242 are partially connected in the second state. The sliding seat 27 is provided with a switching component 5 for switching between the first state and the second state.

[0069] Reference Figure 6 and Figure 7The switching component 5 includes a first airbag 51 and a second airbag 52. The first airbag 51 is installed between the first mounting block 15 and the inner wall of the first mounting groove 271, and the second airbag 52 is installed between the second mounting block 281 and the inner wall of the second mounting groove 272. The first airbag 51 and the second airbag 52 are connected by an air tube. When the valve core 2 is in the second state, the first airbag 51 is in an inflated state.

[0070] In this embodiment, a limiting groove 273 is formed 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. A limiting plate 274 is provided in the first mounting groove 271 and is slidably connected to the limiting groove 273. When 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, the limiting plate 274 is located at one end of the limiting groove 273, and there is a gap between the limiting plate 274 and the first mounting block 15.

[0071] A reset block 282 is provided on the outer wall of the sliding sleeve 28, and a reset groove 275 is provided on the inner wall of the connecting groove 121 for the reset block 282 to slide. The connecting groove 121 is in communication with the outer wall of the sliding seat 27. A first spring 283 is provided between the reset block 282 and the inner wall of the reset groove 275. The elastic force of the first spring 283 is used to put the valve core 2 in the second state.

[0072] In other embodiments, a buffer ring groove is provided on the outer wall of the sliding sleeve 28. When the valve core 2 is in the first state, the buffer ring groove is connected to the first hole 241.

[0073] The implementation principle of Embodiment 2 of this application is as follows:

[0074] The switching component 5 keeps the valve core 2 in the second state (partially connected). At this time, the narrow throttling orifice formed by the first hole 241 and the second hole 242 is formed. During the opening process of the solenoid valve, a small flow of oil slowly enters the connecting groove 21 and is injected into the pressure feedback chamber 111 through the feedback channel, so that the pressure in the chamber can be slowly built up, thereby avoiding the instantaneous hydraulic shock of high pressure oil to the valve core 2 and the push rod 4.

[0075] During this process, the gradually increasing 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. The sliding sleeve 28 begins 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 flow rate also increases smoothly, and the system pressure rises without impact until the two holes are completely aligned, achieving full flow passage. Example 3:

[0076] Secondly, embodiments of this application disclose a hydraulic system.

[0077] Reference Figure 8 A hydraulic system 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 Embodiment 1. One end of the first conveying pipe 61 is connected to a feeding device, and the other end of the first conveying pipe is provided with two first pipes 611, which are respectively connected to an inlet 132 and a 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 is provided with two second pipes 621, which are respectively connected to an outlet 131 and a drive motor 6.

[0078] The implementation principle of this application embodiment is as follows: during the process of high-pressure oil entering the feedback channel, it will abut against the end wall of the feedback channel away from the connecting groove 21, thereby increasing the resistance of the valve core 2 sliding in the sliding groove 133 and slowing down the moving speed of the valve core 2; achieving a buffer effect of smooth opening or closing, making the start and stop of the motor more gentle, maintaining the operational reliability and stability of the entire system, and thus improving the service life of the excavator.

[0079] The above are preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made to the structure, shape and principle of this application should be covered within the scope of protection of this 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 outlet (131) has a sliding groove (133) at one end near the sleeve (1). The sleeve (1) has a pressure feedback chamber (111) which is connected to the sliding groove (133) through a connecting groove (121). The push rod (4) is slidably installed in the pressure feedback chamber (111). 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) has a first feedback channel (26) connected by a connecting groove (21). The push rod (4) has 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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