Gearbox gear shifting neutral position control valve

Abstract

The utility model discloses a gearbox gear shifting neutral position control valve which comprises a valve body, a first sliding cavity and a second sliding cavity which are coaxially arranged are arranged in the valve body, a piston is arranged in the first sliding cavity in a sliding mode, a piston rod is fixedly installed on the piston, and the piston rod penetrates through the front side and the rear side of the piston. The rear end of the piston rod is slidably arranged in the second sliding cavity. An oil discharging groove is formed in the rear end of the piston rod; an oil discharging flow channel is formed in the second sliding cavity; the hydraulic cylinder further comprises a piston driving oil way, the piston driving oil way comprises a first flow channel and a second flow channel, the first flow channel is communicated with the inner end of the first sliding cavity, and the second flow channel is communicated with the outer end of the second sliding cavity. The gear shifting push-pull rod can automatically stop at the gear shifting neutral position, a neutral gear does not need to be manually engaged, operation is more convenient, and the structure is simpler.

Description

Technical Field

[0001] This utility model relates to a gearbox shift mid-position control valve, belonging to the field of gearbox shift mid-position control technology. Background Technology

[0002] In today's society, with social development and technological progress, people's requirements for the comfort and reliability of mobile machinery are becoming increasingly higher. Existing agricultural machinery transmissions come in two forms: mechanical shifting and hydraulic shifting. Hydraulic shifting transmissions account for over 70% of all agricultural machinery transmissions. This type of transmission consists of several planetary gear sets and several clutches. The gear arrangement includes three forward and three reverse gears, six forward and three reverse gears, nine forward and one reverse gear, etc. Planetary power shift transmissions are frequently used as the mechanism for changing the speed and torque from the agricultural machinery engine. Their advantage is that they are easy and simple to operate.

[0003] However, in existing technologies, hydraulic shift transmissions typically achieve gear shifting by pushing a gear shift fork with a shift push-pull rod. During gear shifting, the transmission directly changes from one gear to another. The shift push-pull rod cannot stop in the middle position, requiring a separate neutral position, which makes it inconvenient to control the transmission in the middle position.

[0004] In conclusion, the existing technology obviously has inconveniences and defects in practical use, so it is necessary to improve it. Utility Model Content

[0005] This utility model addresses the shortcomings of the prior art by providing a gearbox shift center control valve, which can automatically stop the shift push-pull lever at the shift center position, eliminating the need for manual shifting to neutral, making operation more convenient and the structure simpler.

[0006] To solve the above technical problems, the present invention adopts the following technical solution:

[0007] A gearbox shift center control valve includes a valve body, in which a first sliding cavity and a second sliding cavity are coaxially arranged. A piston is slidably arranged in the first sliding cavity, and a piston rod is fixedly installed on the piston. The piston rod passes through the front and rear sides of the piston, and the rear end of the piston rod is slidably arranged in the second sliding cavity.

[0008] The piston rod has an oil discharge groove at its rear end and an oil discharge channel in the second sliding cavity;

[0009] It also includes a piston drive oil circuit, which includes a first flow channel and a second flow channel. The first flow channel is connected to the inner end of the first sliding cavity, and the second flow channel is connected to the outer end of the second sliding cavity.

[0010] Furthermore, it also includes a two-position four-way valve, which is connected to the oil outlet of the unloading channel, and the oil inlet pipe of the unloading channel is connected to the main oil inlet circuit.

[0011] Furthermore, the front end of the piston rod extends beyond the valve body and is connected to the shift push-pull rod.

[0012] Furthermore, the inner diameter of the first sliding cavity is adapted to the outer diameter of the piston, and the inner diameter of the second sliding cavity is adapted to the diameter of the piston rod.

[0013] Furthermore, the outer end of the first sliding cavity is provided with a sealing plug, which is threaded onto the valve body, and the front end of the piston rod extends beyond the sealing plug.

[0014] Furthermore, the oil unloading groove is an annular groove arranged around the piston rod.

[0015] Furthermore, the piston drive oil circuit also includes a three-position four-way valve, which controls the flow of hydraulic oil in the first and second flow channels.

[0016] Compared with the prior art, the present invention, by adopting the above technical solution, has the following advantages:

[0017] When the shift position is reached, the oil unloading trough slides to the oil unloading channel, connecting the oil outlet and inlet of the channel. This allows the hydraulic oil from the main inlet circuit to flow directly back to the oil tank through the oil unloading channel, thus stopping the piston in the neutral position. This automatically stops the shift lever in the neutral position, eliminating the need to set neutral and making operation more convenient.

[0018] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of this utility model;

[0020] Figure 2 This is a front view of the present invention;

[0021] Figure 3 yes Figure 2 A half-section view;

[0022] Figure 4 The oil circuit diagram of this utility model.

[0023] In the picture,

[0024] 1-Valve body, 2-Two-position four-way valve, 3-Three-position four-way valve, 4-Piston rod, 5-Piston, 6-Unloading groove, 7-First flow channel, 8-Second flow channel, 9-Unloading flow channel, 10-Sealing plug, 11-First sliding cavity, 12-Second sliding cavity, 13-Main oil inlet circuit. Detailed Implementation

[0025] To provide a clearer understanding of the technical features, objectives, and effects of this utility model, the specific embodiments of this utility model are now described with reference to the accompanying drawings.

[0026] like Figure 1-4 As shown, this utility model provides a gearbox shifting center control valve, including a valve body 1. The valve body 1 has a first sliding cavity 11 and a second sliding cavity 12 arranged coaxially. A piston 5 is slidably arranged in the first sliding cavity 11. A piston rod 4 is fixedly installed on the piston 5. The piston rod 4 passes through the front and rear sides of the piston 5. The rear end of the piston rod 4 is slidably arranged in the second sliding cavity 12.

[0027] The piston rod 4 has an oil discharge groove 6 at its rear end and an oil discharge channel 9 inside the second sliding cavity 12.

[0028] This utility model also includes a piston drive oil circuit, which includes a first flow channel 7 and a second flow channel 8. The first flow channel 7 is connected to the inner end of the first sliding cavity 11, and the second flow channel 8 is connected to the outer end of the second sliding cavity 12.

[0029] This utility model also includes a two-position four-way valve 2, which is connected to the oil outlet of the oil discharge channel 9, and the oil inlet pipe of the oil discharge channel 9 is connected to the main oil inlet circuit 13. When the oil discharge trough 6 slides to the oil discharge channel 9, the oil outlet of the oil discharge channel 9 is connected to the oil inlet, so that the hydraulic oil in the main oil inlet circuit 13 flows directly back to the oil tank from the oil discharge channel 9.

[0030] The front end of the piston rod 4 extends beyond the valve body 1, and the front end of the piston rod 4 is connected to the shift push-pull rod (not shown in the figure).

[0031] The inner diameter of the first sliding cavity 11 is adapted to the outer diameter of the piston 5, and the inner diameter of the second sliding cavity 12 is adapted to the diameter of the piston rod 4.

[0032] The outer end of the first sliding cavity 11 is provided with a sealing plug 10, which is threaded onto the valve body 1, and the front end of the piston rod 4 extends beyond the sealing plug 10.

[0033] The oil unloading groove 6 is an annular groove arranged around the piston rod 4.

[0034] The piston drive oil circuit also includes a three-position four-way valve 3, which controls the flow of hydraulic oil in the first flow channel 7 and the second flow channel 8, such as... Figure 4 .

[0035] exist Figure 3 There are some process holes in the figure. These process holes are not blocked in the figure and do not affect the understanding of this utility model. The process holes will not be described in detail here.

[0036] The specific working principle of this utility model:

[0037] The main oil inlet circuit 13 supplies oil to the three-position four-way valve 3. When the piston 5 extends outward from the inside, the two-position four-way valve 2 is activated first, connecting the outlet of the unloading flow channel 9 to the oil tank. Then, by controlling the activation of the three-position four-way valve 3, the first flow channel 7 is connected to the main oil inlet circuit 13, and the second flow channel 8 is connected to the oil tank, thereby pushing the piston 5 to move outward, causing the piston rod 4 to push the shift push rod to move.

[0038] When the gear shift reaches the neutral position, the oil unloading trough 6 slides to the oil unloading channel 9, connecting the oil outlet and inlet of the oil unloading channel 9. This allows the hydraulic oil from the main inlet oil circuit 13 to flow directly back to the oil tank through the oil unloading channel 9, thus stopping the piston 5 in the neutral position. When the outlet of the oil unloading channel 9 is disconnected from the oil tank by controlling the two-position four-way valve 2, the piston can drive the oil circuit to shift gears again. This automatically stops the gear shift push lever in the neutral position, eliminating the need for manual shifting to neutral, making operation more convenient and the structure simpler.

[0039] When piston 5 retracts from the outside to the inside, the principle is the same as when piston 5 extends, and will not be repeated here.

[0040] The above description provides examples of the preferred embodiments of this utility model. Any aspects not detailed herein are common knowledge to those skilled in the art. The scope of protection of this utility model is determined by the claims. Any equivalent modifications based on the technical teachings of this utility model are also within the scope of protection of this utility model.

Claims

1. A gearbox shift neutral control valve characterized by: The valve body (1) is provided with a first sliding cavity (11) and a second sliding cavity (12) arranged coaxially, a piston (5) is slidably arranged in the first sliding cavity (11), and a piston rod (4) is fixedly installed on the piston (5) and penetrates through the front and rear sides of the piston (5), with the rear end of the piston rod (4) slidably arranged in the second sliding cavity (12); The rear end of the piston rod (4) is provided with an oil discharging groove (6), and the second sliding cavity (12) is provided with an oil discharging flow channel (9); The piston driving oil circuit comprises a first flow channel (7) and a second flow channel (8), the first flow channel (7) is in communication with the inner end of the first sliding cavity (11), and the second flow channel (8) is in communication with the outer end of the second sliding cavity (12).

2. A gearbox shift neutral control valve as claimed in claim 1, characterised in that: The two-position four-way valve (2) is in communication with the oil outlet of the oil discharging flow channel (9), and the oil inlet pipe of the oil discharging flow channel (9) is in communication with the main oil inlet oil circuit (13).

3. A gearbox shift neutral control valve as claimed in claim 1, characterized in that: The front end of the piston rod (4) extends out of the valve body (1) and is connected with a gear shifting push-pull rod.

4. A gearbox shift neutral control valve as claimed in claim 1, characterized in that: The inner diameter of the first sliding cavity (11) is adapted to the outer diameter of the piston (5), and the inner diameter of the second sliding cavity (12) is adapted to the diameter of the piston rod (4).

5. A gearbox shift neutral control valve as claimed in claim 1, characterized in that: The outer end of the first sliding cavity (11) is provided with a plugging plug (10) which is threadedly installed on the valve body (1), and the front end of the piston rod (4) extends out of the plugging plug (10).

6. A gearbox shift neutral control valve as claimed in claim 1, characterized in that: The oil discharging groove (6) is an annular groove arranged along one circle of the piston rod (4).

7. A gearbox shift neutral control valve as claimed in claim 1, characterized in that: The piston driving oil circuit further comprises a three-position four-way valve (3) for controlling the flow of hydraulic oil in the first flow channel (7) and the second flow channel (8).

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