Gearbox with gear shifting buffering function

Abstract

The invention relates to the field of gearbox gear shifting, and discloses a gear shifting buffering gearbox which comprises an operating valve assembly, a box body, a control system and a clutch assembly, the operating valve assembly is fixed outside the box body, the control system is electrically connected with the operating valve assembly through a wire harness, the clutch assembly is arranged in the box body, and the clutch assembly is electrically connected with the box body. The operating valve assembly is composed of an operating valve body, a buffering valve body, a buffering front valve element, a buffering rear valve element, a buffering valve check block, a steel wire check ring, a buffering valve front buffering spring, a buffering valve middle spring, a first buffering valve rear buffering spring, a second buffering valve rear buffering spring, a plug body, a steel ball, a sealing ring and a gear electromagnetic valve. According to the gear shifting valve, through mutual cooperation of the buffering valve body, the front buffering valve element and the like, flowing of hydraulic oil can be accurately controlled in the gear shifting process, stable gear shifting operation is achieved, gear shifting impact and vibration are effectively reduced, and therefore the riding comfort of operators can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of gearbox shifting, and in particular to a gearbox with shift buffering. Background Art

[0002] Large four-wheel excavators are a type of mechanical equipment widely used in construction, mining, roads and other engineering fields. They work in harsh environments and have frequent and large load changes. In different working scenarios, excavators need to frequently move forward, backward, turn, and switch between various working actions, which places high demands on the gearbox. During excavation operations, the gearbox needs to provide a large torque output to meet the excavation force requirements.

[0003] The Chinese patent with announcement number: CN214331452U, an AMT transmission automatic shift impact buffer device, includes a shift fork ring, a connecting shaft 1, a connecting shaft 2, a piston 1 and a piston 2, one end of the connecting shaft 1 is connected to the piston 1, and the other end is connected to one end of the shift fork ring, one end of the connecting shaft 2 is connected to the piston 2, and the other end is connected to the other end of the shift fork ring, the connecting shaft 1 is sleeved with a spring 1 and the spring 1 is located between the piston 1 and the shift fork ring, the connecting shaft 2 is sleeved with a spring 2 and the spring 2 is located between the piston 2 and the shift fork ring, and buffer retaining rings are also provided on both sides of the shift fork ring.

[0004] In the above scheme, the impact force of the pistons on both sides of the shift fork ring when shifting can be reduced through the buffering effect of the spring, thereby helping to extend the service life of the entire automatic shifting system. However, it has the following disadvantages: this device only buffers the impact force generated by shifting through the elastic deformation of the spring, and does not open a throttling hole according to the requirements of the gear position. It is easy for the different external loads in the gearbox to often lead to poor shifting effects, and impact and vibration are prone to occur during the shifting process, thereby reducing the adaptability and consistency of the gearbox. Summary of the invention

[0005] Purpose of the invention: In order to solve the above technical problems, the present invention provides a gearbox with gear shift buffering, so as to solve the problem that the device only buffers the impact force generated by gear shifting by the elastic deformation of the spring, and does not open a throttling hole according to the requirements of the gear position, which easily causes different external loads in the gearbox and often leads to poor gear shifting effect, and easily causes impact and vibration during the gear shifting process, thereby reducing the adaptability and consistency of the gearbox.

[0006] Technical solution: The present invention provides a gear shift buffer transmission, including a control valve assembly, a housing, a control system, and a clutch assembly. The control valve assembly is fixed to the outside of the housing, the control system is electrically connected to the control valve assembly through a wiring harness, and the clutch assembly is arranged inside the housing.

[0007] Preferably, the control valve assembly consists of a control valve body, a buffer valve body, a front buffer valve core, a rear buffer valve core, a buffer valve block, a wire retaining ring, a front buffer spring of the buffer valve, an intermediate buffer spring of the buffer valve, a first rear buffer spring of the buffer valve, a second rear buffer spring of the buffer valve, a plug body, a steel ball, a sealing ring, and a shift solenoid valve. The buffer valve body is threadedly connected to the control valve body, the front buffer valve core is arranged at the right end of the center hole of the buffer valve body, the rear buffer valve core is arranged in the control valve body, the buffer valve block is arranged at one end of the front buffer valve core, and the wire retaining ring is fixed in the annular groove of the center hole at the right end of the buffer valve body. The buffer spring in front of the buffer valve is slidably set in the through hole d3 of the front buffer valve core, the buffer valve middle spring is slidably set in the through hole d4 of the front buffer valve core, the other end of the buffer valve middle spring is on the circular protrusion of the rear buffer valve core, the first buffer valve rear buffer spring is set in the center c3 of the rear buffer valve core, the second buffer valve rear buffer spring is set in the center c4 of the rear buffer valve core, the plug body is threadedly connected to the inner wall of the buffer valve body, the steel ball is fixed to the left end of the buffer spring in front of the buffer valve, the steel ball is set in the through hole d3 of the front buffer valve core, and is pressed against the right end of the through hole d5 of the front buffer valve core.

[0008] Preferably, the sealing ring is fixed to the inner wall of the control valve body, the inner wall of the sealing ring is in contact with the outer wall of the buffer valve body, and the shift solenoid valve is arranged on the control valve assembly.

[0009] Preferably, the control valve body is a rectangular parallelepiped, and the outer wall of the control valve body is provided with a buffer hole a1, a blind hole a2-a4, a plurality of solenoid valve holes a7-a10, a plurality of blind holes a11-a14, a plurality of solenoid valve holes are three-stage stepped holes, a blind hole a15, a plurality of blind holes a16-a22, and a main oil pressure hole a23. The buffer hole a1 is a four-stage stepped hole, the first stage hole has a blind hole a22 vertically passing through it, the second stage hole is a threaded hole, the third stage hole has a vertical hole a14, and the fourth stage hole has a vertical hole a12. The plurality of solenoid valve holes a7-a10 on the outer wall of the control valve body are three-stage stepped holes, and the stepped holes are The hole a22 is connected with the blind hole a2, the blind hole a11 and the blind hole a13, the solenoid valve hole a9 is connected with the blind hole a21, the solenoid valve hole a10 is connected with the blind hole a20, the main oil pressure hole a23 is connected with the blind hole a12 and the buffer hole a1, the vertical hole a14 is connected with the blind hole a15, the blind hole a4, the blind hole a7, the blind hole a8, the blind hole a9 and the blind hole a10, the solenoid valve hole a7 is connected with the blind hole a3 and the blind hole a16, the solenoid valve hole a8 is connected with the blind hole a17, the solenoid valve hole a9 is connected with the blind hole a18, and the solenoid valve hole a10 is connected with the blind hole a19.

[0010] Preferably, the left end of the outer wall of the buffer valve body is an internal thread, and a plurality of sealing grooves b6-b9 are opened on the outer wall of the buffer valve body. The sealing grooves b6 and b9 are external threads, and five rows of through holes are distributed from left to right, which are through holes b1-b5 with an outer diameter evenly distributed around a circle. The through holes b1, b2, and b5 have annular grooves corresponding to the center holes, and the rightmost center hole has an annular groove.

[0011] Preferably, the central step of the rear buffer valve core is provided with blind holes c3 and blind holes c4, the outer wall of the rear buffer valve core is provided with a through hole c1 on its circumference, the right end face of the circular diameter of the rear buffer valve core is provided with a semicircular groove c2, the central through hole of the front buffer valve core is divided into three parts, namely d4, through hole d5 and through hole d3, a groove d8 is provided at the center of the outer diameter, the groove d8 has through holes d1 evenly distributed around the circumference and a stepped semi-through hole d6, a plurality of small annular grooves d2 are provided on the outer diameter surface, and a semi-through hole d7 is provided on the outer diameter surface to communicate with the central inner hole d3.

[0012] Preferably, the gear solenoid valve is a switch solenoid valve.

[0013] Preferably, the control system consists of a control box, a handle, connecting wires, and a sensor. The control box and the handle are fixed in the cab of the excavator loader, the sensor is installed on the box, and the sensor and the handle are electrically connected to the control box via connecting wires.

[0014] Beneficial effects: Compared with the prior art, the present invention has the following beneficial effects: 1. Through the cooperation of the buffer valve body, the front buffer valve core, etc., the flow of hydraulic oil can be accurately controlled during the gear shifting process, smooth gear shifting operation can be achieved, and the gear shifting shock and vibration can be effectively reduced, thereby improving the riding comfort of the operator, reducing work fatigue, and further extending the service life of each component in the transmission system, reducing the possibility of wear and damage, thereby reducing maintenance costs and improving the reliability and work efficiency of the excavator. The buffer valve body can provide installation and working space for other buffer elements such as the buffer valve core. When shifting, the hydraulic oil flows through the buffer valve body and interacts with the internal buffer elements to achieve buffering of the gear shifting shock. Through the cooperation of the front buffer valve core and the rear buffer valve core, the valve core can move according to the pressure change of the hydraulic oil during gear shifting. By changing the position of the valve core, the flow and pressure of the hydraulic oil can be adjusted to avoid excessive impact at the moment of gear shifting. The rear buffer valve core can further adjust the pressure of the hydraulic oil after the gear shift is completed to stabilize the system in the new gear state. Through the cooperation of the buffer valve block and the wire retaining ring, the movement range of the valve core can be limited to ensure that the valve core moves within the normal working range. The buffer valve block can be fixed on the valve body. When the valve core moves to a certain position, it will contact the block and stop moving. The wire retaining ring can be installed at a specific position of the valve core to prevent the valve core from accidentally falling off or excessive movement during operation. 2. Through the cooperation of the buffer spring in front of the buffer valve, the middle spring of the buffer valve, the buffer spring behind the first buffer valve, and the buffer spring behind the second buffer valve, elastic force can be provided during the buffering process to help the valve core return to its initial position and further adjust the pressure change of the hydraulic oil. When the valve core moves under the pressure of the hydraulic oil, the spring will be compressed and store a certain amount of elastic potential energy. After the gear shift is completed, the spring will release the elastic potential energy and push the valve core back to its initial position. At the same time, it can also play a role of buffering and damping during the movement of the valve core to reduce impact and vibration; 3. Through the cooperation of the plug body, steel ball and sealing ring, the sealing performance of the valve core, valve body, oil pipe joint and other parts can be improved to prevent hydraulic oil leakage and ensure the normal working pressure and performance of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A three-dimensional schematic diagram of the invention; Figure 2 A side view schematic diagram of the control valve body of the invention; Figure 3 It is a cross-sectional schematic diagram of the operating valve body in the invention; Figure 4 A side view schematic diagram of the invention; Figure 5 It is a cross-sectional schematic diagram of the buffer valve body in the invention; Figure 6 It is a cross-sectional schematic diagram of the valve core before buffering in the invention; Figure 7 It is a cross-sectional schematic diagram of the valve core after buffering in the invention; Figure 8 Schematic diagram of the control system of the invention. DETAILED DESCRIPTION

[0016] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.

[0017] like Figure 1-Figure 8 As shown, a gear shift buffer transmission includes a control valve assembly 1, a housing 2, a control system 3, and a clutch assembly 4. The control valve assembly 1 is fixed to the outside of the housing 2, the control system 3 is electrically connected to the control valve assembly 1 through a wiring harness, and the clutch assembly 4 is arranged inside the housing 2.

[0018] The control valve assembly 1 is composed of a control valve body 101, a buffer valve body 102, a front buffer valve core 103, a rear buffer valve core 104, a buffer valve stopper 105, a wire retaining ring 106, a buffer valve front buffer spring 107, a buffer valve middle spring 108, a first buffer valve rear buffer spring 109, and a second buffer valve rear buffer spring 110. , a plug body 111, a steel ball 112, a sealing ring 113, and a shift solenoid valve 114. The buffer valve body 102 is threadedly connected to the operating valve body 101. The front buffer valve core 103 is arranged at the right end of the center hole of the buffer valve body 102. The rear buffer valve core 104 is arranged in the operating valve body 101. The buffer valve stopper 105 is arranged at one end of the front buffer valve core 103. The wire retaining ring 106 is fixed in the annular groove of the center hole of the right end of the buffer valve body 102. The front buffer spring 107 of the buffer valve is slidably arranged in the through hole d3 of the front buffer valve core 103. The intermediate spring 108 of the buffer valve is slidably arranged in the buffer In the through hole d4 of the front valve core 103, the other end of the buffer valve middle spring 108 is on the circular protrusion 1041 of the rear buffer valve core 104, the first buffer valve rear buffer spring 109 is arranged in the central blind hole c3 of the rear buffer valve core 104, the second buffer valve rear buffer spring 110 is arranged in the central blind hole c4 of the rear buffer valve core 104, the plug body 111 is threadedly connected to the inner wall of the buffer valve body 102, the steel ball 112 is fixed to the left end of the buffer valve front buffer spring 107, the steel ball 112 is arranged in the through hole d3 of the front buffer valve core 103, and is pressed against the right end of the through hole d5 of the front buffer valve core 103.

[0019] The sealing ring 113 is fixed on the inner wall of the control valve body 101 , the inner wall of the sealing ring 113 is in contact with the outer wall of the buffer valve body 102 , and the shift solenoid valve 114 is arranged on the control valve assembly 1 .

[0020] The control valve body 101 is a rectangular parallelepiped, and the outer wall of the control valve body 101 is provided with a buffer hole a1, a blind hole a2-a4, 4 solenoid valve holes a7-a10, 4 blind holes a11-a14, 4 solenoid valve holes are three-stage stepped holes, a blind hole a15, 7 blind holes a16-a22, and a main oil pressure hole a23. The buffer hole a1 is a four-stage stepped hole, the first stage hole has a blind hole a22 vertically passing through it, the second stage hole is a threaded hole, the third stage hole has a vertical hole a14, and the fourth stage hole has a vertical hole a12. The 4 solenoid valve holes a7-a10 on the outer wall of the control valve body 101 are three-stage stepped holes. The stepped hole a22 is connected with the blind hole a2, the blind hole a11 and the blind hole a13, the solenoid valve hole a9 is connected with the blind hole a21, the solenoid valve hole a10 is connected with the blind hole a20, the main oil pressure hole a23 is connected with the blind hole a12 and the buffer hole a1, the vertical hole a14 is connected with the blind hole a15, the blind hole a4 and the four solenoid valve holes a7-a10, the solenoid valve hole a7 is connected with the blind hole a3 and the blind hole a16, the solenoid valve hole a8 is connected with the blind hole a17, the solenoid valve hole a9 is connected with the blind hole a18, and the solenoid valve hole a10 is connected with the blind hole a19.

[0021] The left end of the inner wall of the buffer valve body 102 is an internal thread, and the outer wall of the buffer valve body 102 is provided with four sealing grooves b6-b9. The sealing grooves b6 and b9 are provided with external threads. Five rows of through holes are distributed from left to right, which are through holes b1-b5 with an outer diameter evenly distributed around a circle. The through holes b1, b2 and b5 have annular grooves corresponding to the center holes, and the rightmost center hole has an annular groove.

[0022] The central step of the valve core 104 after buffering is provided with blind holes c3 and blind holes c4, the circumference of the outer wall of the valve core 104 after buffering is provided with a through hole c1, the right end face of the diameter of the valve core 104 after buffering is provided with a semicircular groove c2, the central through hole of the valve core 103 before buffering is divided into three parts d4, d5 and d3, the center of the outer diameter is provided with a groove d8, d8 has circumferentially evenly distributed through holes d1 and a stepped semi-through hole d6, the outer diameter surface is provided with a number of small annular grooves d2, and the outer diameter surface has a semi-through hole d7 connected to the central inner hole d3.

[0023] The control system 3 consists of a control box 31, a handle 32, a connecting line 33, and a sensor 34. The control box 31 and the handle 32 are fixed in the cab of the excavator loader, and the sensor 34 is installed on the box 2. The sensor 34 and the handle 32 are electrically connected to the control box 31 through the connecting line 33.

[0024] During use, the host outputs different gear signals through the human-machine interaction of the handle 32 according to different working conditions. When the neutral gear is changed to the first gear, the handle 32 rotates to the first gear, and the signal is transmitted to the control box 31. The control box 31 controls the first gear solenoid valve 114 to open through the connecting line 33. The hydraulic oil enters the blind hole a12 from the main oil pressure port a23, enters the hole b5 and the corresponding annular groove of the buffer valve body 102, and enters the central through hole d3 of the buffer front valve core 103 through the intercepting hole d7 of the buffer front valve core 103. The steel ball 112 seals the hydraulic oil and enters the through hole d4 from the through hole d3 of the buffer front valve core 103. The hydraulic oil enters the groove d8 from the through hole d1, pushing the buffer front valve core 103 to move left, and the through hole b4 of the buffer valve body 102 blocked by the groove d8 of the buffer front valve core 103 slowly moves. becomes larger, and the hydraulic oil enters the groove d8 from the through hole d1 of the front buffer valve core 103. Under the action of the sealing ring 113, d8 is a sealed space. As the through hole b4 of the buffer valve body 102 becomes larger, a part of the hydraulic oil enters the vertical hole a14 from the through hole b4 of the buffer valve body 102, and the other part of the hydraulic oil enters the throttle hole d6 through the groove d8 of the front buffer valve core 103, enters the through hole b3 of the buffer valve body 102 through the center through hole d5 and through hole d4 of the front buffer valve core 103, enters the through hole b2 in the sealed space formed by the buffer valve body 102, the operating valve body 101 and the sealing ring 113, enters the center hole c4 through c1 of the rear buffer valve core 104, enters the blind hole a22 from the through hole b1 of the buffer valve body 102, and finally enters the inside of the box body 2. As the front buffer valve core 103 moves to the left, the front buffer valve core 103 gradually blocks the through hole b3 of the buffer valve body 102. The front buffer valve core 103 pushes the buffer valve middle spring 108 to move the rear buffer valve core 104 to the left, gradually blocking the through hole b2 of the buffer valve body 102. The oil pressure of the central through hole d5 and through hole d4 of the front buffer valve core 103 is reduced and discharged from the through hole b3 and through hole b2 of the buffer valve body 102 to the blind hole a22. The pressure on the left side of the front buffer valve core 103 gradually increases until the pressure on the left and right sides of the front buffer valve core 103 is balanced. The front buffer valve core 103 no longer moves. According to the change of working load, the system pressure and flow are balanced to achieve the mitigation of impact pressure and absorb impact energy. Finally, all the hydraulic oil enters the housing from the through hole b4 of the buffer valve body 102 through the blind holes a14, a15, a4, the solenoid valve hole a7, the blind hole a3, and the blind hole a16 to reach the first gear clutch pack.

[0025] Similar to when the gear shifts from neutral to second gear, the handle 32 rotates to the second gear, and the control box 31 transmits a signal through the connecting line 33 to the second gear position solenoid valve 114 to open, and the hydraulic oil enters the blind hole a12 from the main oil pressure hole a23, enters the b5 hole and the corresponding annular groove of the buffer valve body 102, and enters the central through hole d3 of the front buffer valve core 103 through the shut-off hole d7 of the front buffer valve core 103, enters the groove d8 from the through hole d1 of the front buffer valve core 103, and then enters the blind hole a14, blind hole a15, blind hole a4, solenoid valve hole a8, blind hole a17 through the through hole b4 of the buffer valve body 102 in sequence, and enters the housing to reach the second gear clutch package, and the second gear clutch package is combined to transmit power.

[0026] When the neutral gear is to the third gear, the handle 32 is rotated to the third gear, and the control box 31 transmits a signal through the connecting line 33 to the third gear position solenoid valve 114 to open, and the hydraulic oil enters the blind hole a12 from the main oil pressure hole a23, enters the b5 hole and the corresponding annular groove of the buffer valve body 102, and enters the central through hole d3 of the front buffer valve core 103 through the intercepting hole d7 of the front buffer valve core 103, enters the groove d8 from the through hole d1 of the front buffer valve core 103, and then enters the blind hole a14, blind hole a15, blind hole a4, solenoid valve hole a9, blind hole a18 through b4 of the buffer valve body 102 in turn, and enters the housing to reach the third gear clutch package, and the third gear clutch package is combined to transmit power.

[0027] When the gear is in neutral to the fourth gear, the handle 32 rotates to the fourth gear, and the control box 31 transmits a signal through the connecting line 33 to the fourth gear solenoid valve 114 to open. The hydraulic oil enters the blind hole a12 hole from the main oil pressure hole a23, enters the hole b5 and the corresponding annular groove of the buffer valve body 102, enters the central through hole d3 of the front buffer valve core 103 through the shut-off hole d7 of the front buffer valve core 103, enters the groove d8 from the through hole d1 of the front buffer valve core 103, and then enters the blind hole a14, blind hole a15, blind hole a4, solenoid valve hole a10, blind hole a19 through the through hole b4 of the buffer valve body 102 in turn, and enters the housing to reach the fourth gear clutch package. The fourth gear clutch package is combined to transmit power.

[0028] The first-gear magnetic valve oil return route is through blind holes a11, a2 and a22 to the interior of the casing; the second-gear magnetic valve oil return route is through blind holes a13, a2 and a22 to the interior of the casing, and the blind hole a22 does not leak due to the two sealing rings 113; the third-gear magnetic valve oil return is through blind hole a21 to the interior of casing 2; the fourth-gear magnetic valve oil return is through blind hole a20 to the interior of casing 1.

[0029] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A gearbox with shift buffer, comprising a control valve assembly (1), a housing (2), a control system (3), and a clutch assembly (4), characterized in that: The control valve assembly (1) is fixed outside the housing (2), the control system (3) is electrically connected to the control valve assembly (1) via a wiring harness, and the clutch assembly (4) is arranged inside the housing (2).

2. A gearbox with shift buffer according to claim 1, characterized in that: The control valve assembly (1) comprises a control valve body (101), a buffer valve body (102), a front buffer valve core (103), a rear buffer valve core (104), a buffer valve stopper (105), a wire retaining ring (106), a buffer valve front buffer spring (107), a buffer valve intermediate spring (108), a first buffer valve rear buffer spring (109), a second buffer valve rear buffer spring (110), a plug body (111), a steel ball (112), a sealing ring (113), and a shift position solenoid valve (114).

3. A gearbox with shift buffer according to claim 2, characterized in that: The buffer valve body (102) is threadedly connected to the operating valve body (101); the front buffer valve core (103) is arranged at the right end of the center hole of the buffer valve body (102); the rear buffer valve core (104) is arranged in the operating valve body (101); the buffer valve stopper (105) is arranged at one end of the front buffer valve core (103); the wire retaining ring (106) is fixed in the annular groove of the center hole at the right end of the buffer valve body (102); the front buffer spring (107) of the buffer valve is slidably arranged in the through hole d3 of the front buffer valve core (103); the intermediate buffer spring (108) of the buffer valve is slidably arranged in the through hole d4 of the front buffer valve core (103); and the other end of the intermediate buffer spring (108) of the buffer valve is arranged on the circular protrusion (1041) of the rear buffer valve core (104). The first buffer valve rear buffer spring (109) is arranged in the central blind hole c3 of the buffer rear valve core (104), the second buffer valve rear buffer spring (110) is arranged in the central blind hole c4 of the buffer rear valve core (104), the plug body (111) is threadedly connected to the inner wall of the buffer valve body (102), the steel ball (112) is fixed to the left end of the buffer valve front buffer spring (107), the steel ball (112) is arranged in the through hole d3 of the buffer front valve core (103), and is pressed against the right end of the through hole d5 of the buffer front valve core (103), the sealing ring (113) is fixed to the inner wall of the control valve body (101), the inner wall of the sealing ring (113) is in contact with the outer wall of the buffer valve body (102), and the shift solenoid valve (114) is arranged on the control valve assembly (1).

4. A gearbox with shift buffer according to claim 3, characterized in that: The buffer valve intermediate spring (108) is axially positioned by the right end face of the through hole d4 of the buffer front valve core (103) and the right end face of the large diameter of the buffer rear valve core (104).

5. A gearbox with shift buffer according to claim 2, characterized in that: The control valve body (101) is a rectangular parallelepiped. The outer wall of the control valve body (101) is provided with a buffer hole a1, blind holes a2-a4, three-stage stepped solenoid valve holes a7-a10, blind holes a11-a14, blind holes a15, blind holes a16-a22, and a main oil pressure hole a23. The buffer hole a1 is a four-stage stepped hole. The first stage hole has a blind hole a22 vertically passing through it. The second stage hole is a threaded hole. The third stage hole has a vertical hole a14. The fourth stage hole has a vertical blind hole a12. The solenoid valve holes a7-a10 on the outer wall of the control valve body (101) are three-stage stepped holes. The blind holes a22 and a blind hole a15 are respectively provided with a vertical hole a14 and a vertical hole a12.

2. The blind hole a11 and the blind hole a13 are connected, the solenoid valve hole a9 and the blind hole a21 are connected, the solenoid valve hole a10 and the blind hole a20 are connected, the main oil pressure hole a23 and the blind hole a12 and the blind hole a1 are connected, the vertical hole a14 and the blind hole a15, the blind hole a4, the solenoid valve hole a7, the solenoid valve hole a8, the solenoid valve hole a9 and the solenoid valve hole a10 are connected, the solenoid valve hole a7 and the blind hole a3 and the blind hole a16 are connected, the solenoid valve hole a8 and the blind hole a17 are connected, the solenoid valve hole a9 and the blind hole a18 are connected, and the solenoid valve hole a10 and the blind hole a19 are connected.

6. A gearbox with shift buffer according to claim 2, characterized in that: The left end of the inner wall of the buffer valve body (102) is internally threaded, and the outer wall of the buffer valve body (102) is provided with four sealing grooves b6-b9, and the sealing grooves b6 and b9 are connected with external threads. From left to right, five rows of through holes are arranged, which are through holes b1-b5 with an outer diameter evenly distributed around the periphery. The through holes b1, b2, and b5 have annular grooves corresponding to the center holes, and the rightmost center hole has an annular groove.

7. A gearbox with shift buffer according to claim 2, characterized in that: The central step of the buffer rear valve core (104) is provided with a blind hole c3 and a blind hole c4, the outer wall of the buffer rear valve core (104) is provided with a through hole c1, and the right end surface of the circular diameter of the buffer rear valve core (104) is provided with a semicircular groove c2.

8. A gearbox with shift buffer according to claim 2, characterized in that: The central through hole of the buffer front valve core (103) is divided into three parts: through hole d4, through hole d5 and through hole d3. A groove d8 is provided at the center of the outer diameter. The groove d8 contains through holes d1 evenly distributed around the circumference and a stepped semi-through hole d6. The outer diameter surface has a plurality of small annular grooves d2. The outer diameter surface has a semi-through hole d7 connected to the central inner hole d3.

9. A gearbox with shift buffer according to claim 2, characterized in that: The shift solenoid valve (114) is a switch solenoid valve.

10. The gearbox with shift buffer according to claim 1, characterized in that: The control system (3) is composed of a control box (31), a handle (32), a connecting line (33), and a sensor (34); the control box (31) and the handle (32) are fixed in the cab of the excavator loader; the sensor (34) is installed on the box (2); and the sensor (34) and the handle (32) are electrically connected to the control box (31) via the connecting line (33).

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