Pilot valve, pilot-operated hydraulic valve, and working machine

Abstract

The invention relates to the technical field of operation machinery, and discloses a pilot valve, a pilot type hydraulic valve and operation machinery, which comprise a valve shell, a valve core, a propelling device and a thrust-back device. The valve shell is provided with a valve groove, a pilot groove, a first channel, a second channel and a third channel. The first channel communicates with the valve groove, the second channel communicates with the valve groove, and the valve groove communicates with the pilot groove through the third channel. The valve element is inserted into the valve groove in a sliding mode. The valve element is provided with a fourth channel and a fifth channel, and when the valve element is located at the first position, the first channel communicates with the third channel through the fourth channel. When the valve element is located at the second position, the second channel communicates with the third channel through the fifth channel. The propelling device is arranged on the valve shell and suitable for pushing the valve element to slide towards the second position. The push-back mechanism is arranged on the valve shell and suitable for pushing the valve element to slide towards the first position. The propelling device and the thrust-back device are used for directly acting on the valve element, compared with an electromagnetic valve, the hysteresis phenomenon is avoided, and the response efficiency is higher.

Description

Technical Field

[0001] The present application relates to the technical field of operating machinery, and in particular to a pilot valve, a pilot hydraulic valve and an operating machinery. Background Art

[0002] The pilot hydraulic valve is an important control element in the hydraulic system. It mainly controls the flow direction and pressure of the fluid to achieve precise control and regulation of the actuator (such as hydraulic cylinders, hydraulic motors, etc.). The pilot hydraulic valve includes a pilot valve and a hydraulic valve. The pilot groove of the pilot valve is connected to the hydraulic valve. The pilot valve controls the oil to enter and discharge the pilot groove, which can control the movement of the main valve body of the hydraulic valve. At present, the pilot valve adopts an electric control valve or a digital valve. The electric control valve mainly uses a solenoid valve to control the output pilot oil pressure to push the main valve body compression spring to move, and the digital valve realizes closed-loop control through a solenoid valve and a displacement sensor.

[0003] The working principle of the solenoid valve is based on the principle of electromagnetic induction. The movement of the valve core is controlled by controlling the on and off of the electromagnetic coil, thereby controlling the on and off or flow direction of the fluid. During the process of powering on and off, the magnetic induction intensity will not immediately change to a value proportional to the change in current, but there is a certain lag phenomenon, which makes the response efficiency of the pilot hydraulic valve using the solenoid valve as the pilot valve poor. Summary of the invention

[0004] In view of this, the present application provides a pilot valve, a pilot hydraulic valve and an operating machine to solve the problem of poor response efficiency of a pilot hydraulic valve using a solenoid valve as a pilot valve.

[0005] In a first aspect, the present application provides a pilot valve, comprising:

[0006] A valve housing is provided with a valve groove, a pilot groove, a first channel, a second channel and a third channel, wherein the first channel is communicated with the valve groove and is used to pass oil, the second channel is communicated with the valve groove and is used to discharge oil, and the valve groove and the pilot groove are communicated with each other through the third channel;

[0007] a valve core, slidably inserted in the valve groove and capable of sliding between a first position and a second position, the valve core being provided with a fourth channel and a fifth channel, the first channel being communicated with the third channel through the fourth channel when the valve core is in the first position, and the second channel being communicated with the third channel through the fifth channel when the valve core is in the second position;

[0008] A propulsion device, disposed on the valve housing and adapted to push the valve core at the first end of the valve core to slide toward the second position;

[0009] The push-back mechanism is arranged on the valve housing and is suitable for pushing the valve core at the second end of the valve core to slide toward the first position.

[0010] Optionally, the push-back mechanism comprises:

[0011] A first elastic member, wherein the second end of the valve core is connected to the valve housing through the first elastic member, and when the valve core is in the second position, the first elastic member is compressed, and when the first elastic member rebounds, it can drive the valve core to slide toward the second position.

[0012] Optionally, the push-back mechanism further includes:

[0013] A connecting core is slidably inserted in the pilot groove, and the connecting core is connected to the main valve body of the hydraulic valve and slides synchronously;

[0014] A sliding core, wherein the valve housing is provided with a sliding core groove respectively connected with the valve groove and the pilot groove, the sliding core is slidably arranged in the sliding core groove, a first inclined surface is arranged on the side wall of the connecting core, the first inclined surface is inclined inwardly in the direction in which the connecting core is inserted into the pilot groove, the sliding core extends into the pilot groove and abuts against the first inclined surface;

[0015] a second elastic member, the slide core is connected to an end of the slide core groove away from the pilot groove through the second elastic member;

[0016] A sliding member is connected to the first elastic member, a second inclined surface is arranged on the side wall of the sliding core, the second inclined surface is inclined inwardly in the direction in which the sliding core is inserted into the sliding core groove, and a side of the sliding member away from the first elastic member abuts against the second inclined surface.

[0017] Optionally, the propulsion device is configured as a linear motor, and a push rod of the linear motor abuts against a first end of the valve core.

[0018] Optionally, the valve housing includes a valve housing body and a valve core sleeve, the valve housing body is provided with a valve hole, the valve core sleeve is inserted into the valve hole, the inner periphery of the valve core sleeve forms the valve groove, the pilot groove, the first channel, the second channel and the third channel are all opened on the valve housing body, and the propulsion device and the push-back device are both arranged on the valve housing body.

[0019] Optionally, a first annular groove is provided on the outer wall of the valve housing body, the third channel is aligned with and connected to the first annular groove, a first opening connected to the valve groove is provided at the bottom of the first annular groove, when the valve core is in the first position, the first channel is connected to the first opening through the fourth channel, and when the valve core is in the second position, the second channel is connected to the first opening through the fifth channel.

[0020] Optionally, the first channel includes:

[0021] A first through hole, which is formed on the valve housing body and communicates with the valve hole;

[0022] A second annular groove is formed on the outer wall of the valve core sleeve, and the second annular groove is aligned with and communicated with the first through hole;

[0023] A second opening is formed at the bottom of the second annular groove and is connected to the valve groove. When the valve core is in the first position, the second opening is connected to the first opening through the fourth channel. When the valve core is in the second position, the first opening and the second opening are respectively cut off from the fourth channel.

[0024] Optionally, the fifth channel comprises:

[0025] A third annular groove is provided on the valve core;

[0026] an inner channel, disposed in the valve core, the inner channel being in communication with the second channel;

[0027] The third opening is formed at the bottom of the third annular groove and communicates with the inner channel. When the valve core is in the second position, the first opening is aligned with and communicates with the third annular groove.

[0028] Optionally, a mounting groove for mounting the propulsion device is provided on the valve housing body, the valve hole is opened on the bottom wall of the mounting groove, the second channel is communicated with the mounting groove, and the fifth channel is communicated with the mounting groove.

[0029] In a second aspect, the present application also provides a pilot hydraulic valve, comprising any of the above-mentioned pilot valves.

[0030] In a third aspect, the present application also provides a working machine, comprising the pilot hydraulic valve described above.

[0031] The present application provides a pilot valve, comprising: a valve housing, a valve core, a propulsion device and a push-back mechanism. The valve housing is provided with a valve groove, a pilot groove, a first channel, a second channel and a third channel. The first channel is connected to the valve groove, and the second channel is connected to the valve groove. The first end of the third channel is connected to the valve groove, and the second end of the third channel is connected to the pilot groove. The valve core is slidably inserted in the valve groove and can slide between a first position and a second position, and a fourth channel and a fifth channel are provided on the valve core. The propulsion device can push the valve core to slide from the first position to the second position. The push-back mechanism can push the valve core to slide from the second position to the first position. The pilot valve is connected to the hydraulic valve controlled by it, so that when the oil enters the pilot groove, the main valve body of the hydraulic valve can be pushed to move in a direction away from the pilot valve. When the oil flows out of the pilot groove, the main valve body of the hydraulic valve moves in a direction close to the pilot valve.

[0032] When the propulsion device pushes the first end of the valve core to the first position, the first channel is connected to the fourth channel, the fourth channel is connected to the pilot groove, the second channel is cut off from the fifth channel, and the fifth channel is cut off from the pilot groove. The oil enters from the first channel and then enters the pilot groove through the fourth channel. Thereby, the main valve body of the hydraulic valve is pushed to move in the direction away from the pilot valve. When it is necessary to adjust the main valve body back to the middle position, the propulsion device is used to push the second end of the valve core so that the valve core slides from the first position to the second position, the first channel is cut off from the fourth channel, the fourth channel is cut off from the pilot groove, the second channel is connected to the fifth channel, and the fifth channel is connected to the pilot groove. The oil is discharged from the pilot groove through the fifth channel and the second channel, so that the main valve body of the hydraulic valve moves in the direction close to the pilot valve until it returns to the middle position. In this way, the propulsion device and the push-back device are used to directly act on the valve core, and there is no hysteresis phenomenon compared to the use of the solenoid valve, and the response efficiency is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0034] Figure 1 This is a schematic structural diagram of a pilot valve according to an embodiment of the present application;

[0035] Figure 2 This is a schematic diagram of a valve core of a pilot valve according to an embodiment of the present application being in a second position;

[0036] Figure 3 for Figure 2 A is a partial enlarged schematic diagram;

[0037] Figure 4 This is a schematic diagram of a valve core of a pilot valve according to an embodiment of the present application being in a first position;

[0038] Figure 5 for Figure 4 A partial enlarged schematic diagram of B in the middle;

[0039] Figure 6 This is a schematic diagram of a valve housing structure of a pilot valve according to an embodiment of the present application;

[0040] Figure 7 This is a schematic diagram of the valve core sleeve structure of a pilot valve in an embodiment of the present application;

[0041] Figure 8 A schematic diagram of a valve core structure of a pilot valve according to an embodiment of the present application;

[0042] Fig. 9 This is a schematic structural diagram of a pilot hydraulic valve according to an embodiment of the present application.

[0043] Description of reference numerals:

[0044] 1. Valve housing; 2. Valve core; 3. Propulsion device; 4. Push-back mechanism; 41. First elastic member; 42. Connecting core; 43. Sliding core; 44. Second elastic member; 45. Sliding member; 5. First passage; 51. First through hole; 52. Second annular groove; 53. Second opening; 6. Second passage; 7. Third passage; 8. Fourth passage; 9. Fifth passage; 91. Third annular groove; 92. Inner passage; 93. Third opening; 94. Fifth annular groove; 95. Fifth opening; 10. Valve groove; 11. Pilot groove; 12. Main valve body; 13. Sliding core groove; 14. Screw plug; 15. First inclined surface; 16. Second inclined surface; 17. Valve hole; 18. Valve core sleeve; 19. First annular groove; 20. First opening; 21. Mounting groove; 22. Sixth channel; 23. Plug; 24. Connecting groove; 25. Third elastic member; 26. Retaining ring; 27. Main valve housing. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of this application.

[0046] Combine the following Figures 1 to 9 , describing an embodiment of the present application.

[0047] According to an embodiment of the present application, on the one hand, a pilot valve is provided, such as Figure 1 As shown, it includes: a valve housing 1, a valve core 2, a propulsion device 3 and a push-back mechanism 4. The valve housing 1 is provided with a valve groove 10, a pilot groove 11, a first channel 5, a second channel 6 and a third channel 7. The first channel 5 is communicated with the valve groove 10, and oil can enter the valve groove 10 through the first channel 5. The second channel 6 is communicated with the valve groove 10, and oil can flow out of the valve groove 10 through the second channel 6. The first end of the third channel 7 is communicated with the valve groove 10, and the second end of the third channel 7 is communicated with the pilot groove 11, so that oil can flow between the valve groove 10 and the pilot groove 11 through the third channel 7.

[0048] The valve core 2 is slidably inserted in the valve groove 10 and can slide between the first position and the second position. The fourth channel 8 and the fifth channel 9 are opened on the valve core 2. When the valve core 2 is in the first position, the first channel 5 is connected with the fourth channel 8, the fourth channel 8 is connected with the pilot groove 11, the second channel 6 is cut off from the fifth channel 9, and the fifth channel 9 is cut off from the pilot groove 11. At this time, the oil can enter the pilot groove 11 through the first channel 5 and the fourth channel 8 in sequence. When the valve core 2 is in the second position, the first channel 5 is cut off from the fourth channel 8, the fourth channel 8 is cut off from the pilot groove 11, the second channel 6 is connected with the fifth channel 9, and the fifth channel 9 is connected with the pilot groove 11. At this time, the oil can flow out from the pilot groove 11 through the fifth channel 9 and the second channel 6 in sequence.

[0049] The propulsion device 3 is arranged on the valve housing 1 and acts on the first end of the valve core 2. The propulsion device 3 can push the valve core 2 to slide from the first position to the second position. The push-back mechanism 4 is arranged on the valve housing 1 and acts on the second end of the valve core 2. The push-back mechanism 4 can push the valve core 2 to slide from the second position to the first position.

[0050] The pilot valve is connected to the hydraulic valve it controls, so that when the oil enters the pilot groove 11, it can push the main valve body 12 of the hydraulic valve to move away from the pilot valve. When the oil flows out of the pilot groove 11, the main valve body 12 of the hydraulic valve moves toward the pilot valve.

[0051] Under normal conditions, Figure 3 As shown, the main valve body 12 is in the middle position. At this time, the valve core 2 is in the second position, the first channel 5 is cut off from the fourth channel 8, the fourth channel 8 is cut off from the pilot groove 11, the second channel 6 is connected to the fifth channel 9, the fifth channel 9 is connected to the pilot groove 11, and the oil in the pilot groove 11 can be discharged to the oil tank through the fifth channel 9 and the second channel 6. When the position of the main valve body 12 needs to be adjusted, the propulsion device 3 is used to push the first end of the valve core 2, as shown in FIG. Figure 5As shown. The valve core 2 slides from the second position to the first position. At this time, the first channel 5 is connected to the fourth channel 8, the fourth channel 8 is connected to the pilot groove 11, the second channel 6 is disconnected from the fifth channel 9, and the fifth channel 9 is disconnected from the pilot groove 11. The oil enters from the first channel 5 and then passes through the fourth channel 8 into the pilot groove 11. This pushes the main valve body 12 of the hydraulic valve to move away from the pilot valve. When it is necessary to adjust the main valve body 12 back to the middle position, the propulsion device 3 is used to push the second end of the valve core 2, so that the valve core 2 slides from the first position to the second position, as shown. Figure 3 At this time, the first channel 5 is cut off from the fourth channel 8, the fourth channel 8 is cut off from the pilot groove 11, the second channel 6 is connected to the fifth channel 9, and the fifth channel 9 is connected to the pilot groove 11. The oil is discharged from the pilot groove 11 through the fifth channel 9 and the second channel 6, so that the main valve body 12 of the hydraulic valve moves toward the direction close to the pilot valve until it returns to the middle position.

[0052] With such an arrangement, the propulsion device 3 and the push-back device are used to act directly on the valve core 2. Compared with the use of a solenoid valve, there is no hysteresis phenomenon, the response efficiency is higher, and there is no overshoot characteristic and attenuation problem of the solenoid valve, so the user experience is better and the service life is longer.

[0053] The propulsion device 3 may be a linear motor, which is connected to the first end of the valve slot 10, so that the push rod of the linear motor extends into the valve slot 10 and abuts against the first end of the valve core 2. When the push rod of the linear motor extends, the valve core 2 is pushed to move from the first position to the second position. When the push rod of the linear motor retracts, the propulsion device 3 cancels the propulsion force on the valve core 2, and the push-back mechanism 4 can push the valve core 2 to move from the second position to the first position.

[0054] In an optional embodiment, if Figure 2 and Figure 4 As shown, the push-back mechanism 4 includes a first elastic member 41. The first elastic member 41 can be a spring. The first end of the first elastic member 41 is connected to the second end of the valve core 2, and the second end of the first elastic member 41 is connected to the valve housing 1. In this way, when the propulsion device 3 pushes the valve core 2 to move from the first position to the second position, the first elastic member 41 is compressed. When the propulsion device 3 cancels the propulsion force on the valve core 2, the first elastic member 41 rebounds and pushes the valve core 2 to move from the second position to the first position.

[0055] With such arrangement, under the elastic force of the first elastic member 41 , the valve core 2 can slide between the first position and the second position by simply operating the propulsion device 3 , which makes the operation more convenient.

[0056] In a further embodiment, Figure 2 and Figure 4As shown, the push-back mechanism 4 also includes: a connecting core 42, a sliding core 43, a second elastic member 44 and a sliding member 45. The first end of the connecting core 42 is connected to the main valve body 12 of the hydraulic valve, so that the hydraulic valve and the connecting core 42 move synchronously. The second end of the connecting core 42 can be slidably arranged and inserted in the pilot groove 11. When the oil enters the pilot groove 11, the connecting core 42 is pushed to slide in the direction of leaving the pilot groove 11, thereby pushing the main valve body 12 of the hydraulic valve to move away from the pilot valve. When the oil flows out of the pilot groove 11, the connecting core 42 can slide in the direction of inserting into the pilot groove 11, so that the main valve body 12 of the hydraulic valve can move toward the direction close to the pilot valve and reset.

[0057] A core slide groove 13 is provided on the valve housing 1, so that the first end of the core slide groove 13 is communicated with the pilot groove 11, and the second end of the valve groove 10 is communicated with the core slide groove 13. The core slide 43 can be slidably inserted in the core slide groove 13 and can extend into the pilot groove 11 through the first end of the core slide groove 13. The second end of the core slide groove 13 is closed by a screw plug 14 to form the bottom of the core slide groove 13.

[0058] A first inclined surface 15 is provided on the side wall of the connecting core 42, wherein the first inclined surface 15 is inclined inwardly along the direction in which the connecting core 42 is inserted into the pilot groove 11, that is, inclined in the direction close to the axis of the connecting core 42, and the sliding core 43 is abutted against the first inclined surface 15 after extending into the pilot groove 11. The second elastic member 44 may be a spring, and the first end of the second elastic member 44 is connected to the screw plug 14, thereby connecting to the second end of the sliding core groove 13. The second end of the second elastic member 44 is connected to the first end of the sliding core 43, so that under the elastic force of the second elastic member 44, the second end of the sliding core 43 is kept against the first inclined surface 15. When the connecting core 42 slides in the direction of leaving the pilot groove 11, under the elastic force of the second elastic member 44, the second end of the sliding core 43 slides along the first inclined surface 15 and moves in the direction close to the axis of the connecting core 42, so that the sliding core 43 moves in the direction of leaving the sliding core groove 13. When the connecting core 42 slides toward the direction of inserting into the guide groove 11 , the elastic force of the second elastic member 44 is overcome, and the second end of the sliding core 43 slides along the first inclined surface 15 and moves away from the axis of the connecting core 42 , so that the sliding core 43 moves toward the direction of inserting into the sliding core groove 13 .

[0059] A second inclined surface 16 is provided on the side wall of the sliding core 43. The second inclined surface 16 is inclined inwardly along the direction in which the sliding core 43 is inserted into the sliding core groove 13, that is, it is inclined in the direction close to the axis of the sliding core 43. The first end of the sliding member 45 extends into the valve groove 10 and is connected to the second end of the first elastic member 41, and the second end of the sliding member 45 extends into the sliding core groove 13 and abuts against the second inclined surface 16. Thus, the second end of the first elastic member 41 is connected to the valve housing 1. When the sliding core 43 moves in the direction of inserting into the sliding core groove 13, the second end of the sliding member 45 slides along the second inclined surface 16 and moves in the direction away from the axis of the sliding core 43. When the sliding core 43 moves in the direction of leaving the sliding core groove 13, the second end of the sliding member 45 slides along the second inclined surface 16 and moves in the direction close to the axis of the sliding core 43. The sliding member 45 can be a slider.

[0060] In this arrangement, the linear motor serves as the propulsion device 3, and the elasticity of the first elastic member 41 keeps the first end of the valve core 2 against the push rod of the linear motor. When the push rod of the linear motor extends and pushes the valve core 2 to slide from the second position to the first position, the first elastic member 41 is compressed. At the same time, the oil enters the first channel 5 and enters the pilot groove 11 through the fourth channel 8, thereby pushing the connecting core 42 to move in the direction away from the pilot valve. Under the action of the second elastic member 44, the sliding core 43 moves in the direction away from the sliding core groove 13, so that the first elastic member 41 rebounds and the sliding member 45 moves in the direction close to the axis of the sliding core 43. In this way, when the propulsion device 3 pushes the valve core 2 to slide from the second position to the first position, the sliding member 45 also moves in the direction close to the axis of the sliding core 43, so that the first elastic member 41 rebounds to a preset degree of compression. It is prevented that the first elastic member 41 is in a highly compressed state for a long time, and the service life of the first elastic member 41 is increased, thereby increasing the service life of the pilot valve.

[0061] When the push rod of the linear motor retracts, the first elastic member 41 rebounds to make the valve core 2 slide from the first position to the second position. At the same time, the oil is discharged from the pilot groove 11 through the fifth channel 9 and the second channel 6, so that the connecting core 42 moves toward the direction close to the pilot valve. Thereby, the sliding core 43 is pushed to move in the direction of inserting into the sliding core groove 13, and then the sliding member 45 is pushed to slide in the direction away from the axis of the sliding core 43. At this time, the sliding member 45 compresses the first elastic member 41 to a preset compression degree. The first elastic member 41 is always kept at a preset compression degree, which increases the service life of the first elastic member 41.

[0062] Regarding the arrangement of the valve slot 10, in one embodiment, as Figures 6 to 8 As shown, a valve hole 17 is formed on the valve housing 1. After the valve core sleeve 18 is inserted into the valve hole 17, the hole groove inside the valve core sleeve 18 forms the valve groove 10. In this way, it is not necessary to directly form the valve groove 10 on the valve housing 1, and the manufacturing requirements are lower. Moreover, when the valve groove 10 is damaged, the valve core sleeve 18 can be replaced, which is convenient for maintenance and replacement.

[0063] The pilot groove 11 , the first channel 5 , the second channel 6 and the third channel 7 are all provided on the valve housing 1 , and the propulsion device 3 and the push-back device are both connected and arranged on the valve housing 1 .

[0064] In one embodiment, if Figure 3 and Figure 5 As shown, a first annular groove 19 is provided on the outer wall of the valve housing 1 body. After the valve core sleeve 18 is inserted into the valve hole 17, one end of the third channel 7 that enters the valve hole 17 is aligned with the first annular groove 19, so that the third channel 7 is connected to the first annular groove 19. A first opening 20 is provided at the bottom of the first annular groove 19, so that the first opening 20 is connected to the valve groove 10. When the valve core 2 slides to the first position, the first opening 20 is connected to the fourth channel 8, so that the oil can enter the pilot valve through the first channel 5, the fourth channel 8, the first opening 20, the first annular groove 19 and the third channel 7 in sequence. At this time, the first opening 20 is disconnected from the fifth channel 9 to prevent the oil from flowing to the second channel 6. When the valve core 2 slides to the second position, the first opening 20 is connected to the fifth channel 9, so that the oil can flow out of the pilot valve through the third channel 7, the first annular groove 19, the first opening 20, the fifth channel 9 and the second channel 6 in sequence. At this time, the first opening 20 is disconnected from the fourth channel 8 to prevent the oil from flowing to the pilot valve.

[0065] For the first channel 5, in a further embodiment, as Figure 3 and Figure 5 As shown, the first channel 5 includes a first through hole 51, a second annular groove 52 and a second opening 53. The first through hole 51 is provided on the valve housing 1 body so that the first through hole 51 is connected to the inside of the valve hole 17. The second annular groove 52 is provided on the outer wall of the valve core sleeve 18, and the second annular groove 52 is arranged along the circumference of the valve core sleeve 18. After the valve core sleeve 18 is inserted into the valve hole 17, the first through hole 51 is aligned with the second annular groove 52 so that the first through hole 51 is connected to the second annular groove 52. A second opening 53 is provided at the bottom of the second annular groove 52 so that the second opening 53 is connected to the valve groove 10. When the valve core 2 slides to the first position, the second opening 53 is aligned and connected to the fourth channel 8, so that the oil can enter the pilot valve through the first through hole 51, the second annular groove 52, the second opening 53, the fourth channel 8, the first opening 20, the first annular groove 19 and the third channel 7 in sequence. When the valve core 2 slides to the second position, the first opening 20 and the fourth channel 8 are staggered and cut off to prevent the oil from flowing to the pilot valve.

[0066] As for the fourth channel 8, the fourth channel 8 can be a fourth annular groove opened on the outer side wall of the valve core 2, and the fourth annular groove is arranged along the circumference of the valve core 2. When the valve core 2 slides to the first position, the fourth annular groove is aligned and connected with the first opening 20, and when the valve core 2 slides to the second position, the fourth annular groove is staggered and cut off from the first opening 20.

[0067] For the fifth channel 9, in a further embodiment, as Figure 3 and Figure 5 As shown, the fifth channel 9 includes a third annular groove 91, an inner channel 92 and a third opening 93. The inner channel 92 is opened inside the valve core 2, and the inner channel 92 is cylindrical and its axis is coaxial with the axis of the valve core 2. The inner channel 92 is connected to the second channel 6, so that the oil entering the inner channel 92 can flow to the second channel 6 and flow out through the second channel 6.

[0068] The third annular groove 91 is provided on the side wall of the valve core 2, and the third opening 93 is provided at the bottom of the second annular groove 52, so that the third opening 93 is connected to the inner channel 92. The third annular groove 91 is arranged along the circumference of the valve core 2. When the valve core 2 slides to the second position, the first opening 20 is aligned and connected with the third annular groove 91, so that the oil can be discharged through the third channel 7, the first annular groove 19, the first opening 20, the third annular groove 91, the third opening 93, the inner channel 92 and the second channel 6 in sequence. When the valve core 2 slides to the first position, the first opening 20 is staggered and cut off from the third annular groove 91. This prevents the oil from flowing to the second channel 6 for discharge.

[0069] In a further embodiment, Figures 1 to 6 As shown, a mounting groove 21 is provided on the body of the valve housing 1. A valve hole 17 is provided on the bottom wall of the mounting groove 21. After the valve core sleeve 18 is inserted into the valve hole 17, the valve core 2 is inserted into the valve core 2 groove of the valve core sleeve 18, and then the linear motor as the propulsion device 3 is installed in the mounting groove 21 and the notch of the mounting groove 21 is closed, so that the push rod of the linear motor abuts against the first end of the valve core 2. Therefore, when the push rod of the linear motor is extended, the valve core 2 is pushed to move from the first position to the second position.

[0070] The fifth channel 9 further includes a fifth annular groove 94 and a fifth opening 95. The fifth annular groove 94 is formed on the end surface of the first end of the valve core 2, and the fifth opening 95 is formed on the groove wall of the fifth annular groove 94, so that the fifth opening 95 is communicated with the inner channel 92. In this way, the inner channel 92 is communicated with the inside of the mounting groove 21 through the fifth opening 95 and the fifth annular groove 94. The second channel 6 is formed on the body of the valve housing 1 and is communicated with the inside of the mounting groove 21, so that the fifth channel 9 is communicated with the second channel 6 through the mounting groove 21.

[0071] In some embodiments, Figures 1 to 5As shown, a sixth channel 22 is provided on the valve housing 1, so that the sixth channel 22 is connected to the valve slot 10, and a plug 23 is detachably provided in the sixth channel 22, and the plug 23 blocks the sixth channel 22. In this way, when the plug 23 is removed, the movement of the valve core 2 can be used to make the fourth channel 8 or the fifth channel 9 connected to the sixth channel 22 to meet other liquid inlet or outlet requirements. The plug 23 can be installed in the sixth channel 22 for blocking when not in use.

[0072] In addition, a connecting groove 24 is provided on the main body of the valve housing 1, a pilot groove 11 is provided on the bottom wall of the connecting groove 24, a connecting core 42 is connected to the main valve body 12 and extends into the pilot groove 11 through the connecting groove 24, and oil can act on the main valve body 12 after entering the connecting groove 24 from the pilot groove 11. A third elastic member 25 is sleeved on the connecting core 42, and the third elastic member 25 can be a spring, a first end of the third elastic member 25 abuts against the bottom wall of the connecting groove 24, and a second end of the third elastic member 25 abuts against the main valve housing 27 through a retaining ring 26, and the main valve body 12 can push and compress the third elastic member 25 when it moves close to the pilot valve.

[0073] like Fig. 9 As shown, since pilot valves are arranged on both sides of the main valve housing 27, when the first pilot valve is in effect, the main valve body 12 moves toward the second pilot valve, thereby compressing the third elastic member 25 of the second pilot valve. When the first pilot valve is canceled, the third elastic member 25 of the second pilot valve rebounds and pushes the main valve back to the middle position for reset. Similarly, when the second pilot valve is in effect, the main valve body 12 moves toward the first pilot valve, thereby compressing the third elastic member 25 of the first pilot valve. When the second pilot valve is canceled, the third elastic member 25 of the first pilot valve rebounds and pushes the main valve back to the middle position for reset.

[0074] According to an embodiment of the present application, on the other hand, a pilot hydraulic valve is also provided, such as Fig. 9 As shown, the pilot hydraulic valve includes any of the above pilot valves. The pilot hydraulic valve has the same technical effect as the pilot valve, so it will not be described in detail.

[0075] According to an embodiment of the present application, on the other hand, a working machine is provided, including the above pilot hydraulic valve, the working machine has the same technical effect as the pilot hydraulic valve, so it is not repeated here. The working machine includes but is not limited to excavators, cranes, pile drivers, mixers, etc.

[0076] Although the embodiments of the present application are described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present application, and such modifications and variations are all within the scope defined by the present application.

Claims

1. A pilot valve, characterized in that: include: A valve housing (1) is provided with a valve groove (10), a pilot groove (11), a first channel (5), a second channel (6) and a third channel (7); the first channel (5) is communicated with the valve groove (10) and is used for introducing oil; the second channel (6) is communicated with the valve groove (10) and is used for discharging oil; the valve groove (10) and the pilot groove (11) are communicated with each other through the third channel (7); A valve core (2) is slidably inserted in the valve groove (10) and can slide between a first position and a second position. A fourth channel (8) and a fifth channel (9) are provided on the valve core (2). When the valve core (2) is in the first position, the first channel (5) is connected to the third channel (7) through the fourth channel (8). When the valve core (2) is in the second position, the second channel (6) is connected to the third channel (7) through the fifth channel (9). A propulsion device (3) is arranged on the valve housing (1) and is adapted to push the valve core (2) at the first end of the valve core (2) to slide toward the second position; A push-back mechanism (4) is arranged on the valve housing (1) and is suitable for pushing the valve core (2) at the second end of the valve core (2) to slide towards the first position.

2. The pilot valve according to claim 1, characterized in that: The push-back mechanism (4) comprises: A first elastic member (41), wherein the second end of the valve core (2) is connected to the valve housing (1) via the first elastic member (41); when the valve core (2) is in the second position, the first elastic member (41) is compressed, and when the first elastic member (41) rebounds, it can drive the valve core (2) to slide toward the second position.

3. The pilot valve according to claim 2, characterized in that: The push-back mechanism (4) further comprises: A connecting core (42) is slidably inserted into the pilot groove (11), and the connecting core (42) is connected to the main valve body (12) of the hydraulic valve and slides synchronously; A sliding core (43), the valve housing (1) is provided with a sliding core groove (13) which is respectively connected with the valve groove (10) and the pilot groove (11), the sliding core (43) is slidably arranged in the sliding core groove (13), a first inclined surface (15) is arranged on the side wall of the connecting core (42), the first inclined surface (15) is inclined inwardly in the direction in which the connecting core (42) is inserted into the pilot groove (11), the sliding core (43) extends into the pilot groove (11) and abuts against the first inclined surface (15); a second elastic member (44), the slide core (43) being connected to an end of the slide core groove (13) away from the pilot groove (11) via the second elastic member (44); A sliding member (45), the sliding member (45) is connected to the first elastic member (41), a second inclined surface (16) is provided on the side wall of the sliding core (43), the second inclined surface (16) is inclined inwardly in the direction in which the sliding core (43) is inserted into the sliding core groove (13), and a side of the sliding member (45) away from the first elastic member (41) abuts against the second inclined surface (16).

4. The pilot valve according to claim 1, characterized in that: The valve housing (1) comprises a valve housing (1) body and a valve core sleeve (18); the valve housing (1) body is provided with a valve hole (17); the valve core sleeve (18) is inserted into the valve hole (17); the inner periphery of the valve core sleeve (18) forms the valve groove (10); the pilot groove (11), the first channel (5), the second channel (6) and the third channel (7) are all provided on the valve housing (1) body; the propulsion device (3) and the push-back device are both provided on the valve housing (1) body.

5. The pilot valve according to claim 4, characterized in that: A first annular groove (19) is provided on the outer wall of the valve housing (1) body, the third channel (7) is aligned with and communicates with the first annular groove (19), a first opening (20) communicated with the valve groove (10) is provided at the bottom of the first annular groove (19), when the valve core (2) is in the first position, the first channel (5) is communicated with the first opening (20) through the fourth channel (8), and when the valve core (2) is in the second position, the second channel (6) is communicated with the first opening (20) through the fifth channel (9).

6. The pilot valve according to claim 5, characterized in that: The first channel (5) comprises: A first through hole (51) is formed on the valve housing (1) body and is connected to the valve hole (17); A second annular groove (52) is formed on the outer wall of the valve core sleeve (18), and the second annular groove (52) is aligned with and communicates with the first through hole (51); A second opening (53) is provided at the bottom of the second annular groove (52) and is connected to the valve groove (10); when the valve core (2) is in the first position, the second opening (53) is connected to the first opening (20) through the fourth passage (8); when the valve core (2) is in the second position, the first opening (20) and the second opening (53) are respectively cut off from the fourth passage (8).

7. The pilot valve according to claim 5, characterized in that: The fifth channel (9) comprises: A third annular groove (91) is formed on the valve core (2); An inner channel (92) is provided in the valve core (2), and the inner channel (92) is communicated with the second channel (6); The third opening (93) is formed at the bottom of the third annular groove (91) and is connected to the inner channel (92); when the valve core (2) is in the second position, the first opening (20) is aligned with and connected to the third annular groove (91).

8. The pilot valve according to claim 4, characterized in that: The valve housing (1) body is provided with a mounting groove (21) for mounting the propulsion device (3); the valve hole (17) is opened on the bottom wall of the mounting groove (21); the second channel (6) is connected to the mounting groove (21); and the fifth channel (9) is connected to the mounting groove (21).

9. A pilot hydraulic valve, characterized in that: The invention comprises the pilot valve as described in any one of claims 1 to 8.

10. A working machine, characterized in that: Includes the pilot hydraulic valve as described in claim 9.

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