A self-locking structure for preventing the secondary box of a transmission from slipping out of gear

Abstract

The present invention belongs to the technical field of transmissions and relates to a self-locking structure for preventing the secondary box of a transmission from slipping out of gear. It includes a self-locking valve, which comprises a valve body. Inside the valve body, a plug, a spring and a top pin are sequentially installed from top to bottom. One end of the spring is connected to the plug, and the other end is connected to the top pin. At the inner wall of the valve body that cooperates with the top pin, a shoulder is pre-machined. At the middle of the top pin, a stepped surface is pre-machined, and the stepped surface cooperates with the shoulder. The area where the spring is located is the upper air chamber, and the cavity between the stepped surface of the top pin and the shoulder surface of the valve body is the lower air chamber. An upper exhaust hole is opened in the top pin, and a lower exhaust hole is opened at the lower part of the valve body. The upper air chamber is connected to the lower air chamber through the upper exhaust hole, and the lower air chamber is connected to the outside of the valve body through the lower exhaust hole. The front end of the top pin acts on the secondary box shift fork shaft, and three grooves are opened on the secondary box shift fork shaft. The three grooves correspond to the three working states of the transmission. Therefore, the probability of gear slipping during the working process can be reduced, and the reliability of the transmission operation can be ensured.

Description

Technical Field

[0001] The present invention belongs to the technical field of transmissions and relates to a self-locking structure for preventing the secondary box of a transmission from falling out of gear. Background Art

[0002] At present, there is a logical contradiction in the structure of the main and secondary box interlock of the S transmission used in batches and the gear shifting state structure when the PTO is present. Therefore, the main and secondary box interlock structures are not equipped for transmissions with PTO, which makes it impossible to prevent the secondary box from falling out of gear when the main box is in gear, and is not conducive to the stable operation of the transmission. At the same time, there is a problem that the internal exhaust of some similar self-locking valves is not smooth, and there is a risk of forming a dead cavity, resulting in the self-locking valve not working properly and even affecting the working performance of the transmission. Summary of the Invention

[0003] In order to overcome the defects existing in the above-mentioned prior art, the purpose of the present invention is to provide a self-locking structure for preventing the secondary box of a transmission from falling out of gear, which can prevent the secondary box from falling out of gear, improve the reliability during the driving process of the transmission, and solve the problem of unsmooth internal exhaust of the self-locking valve body.

[0004] The present invention is realized through the following technical solutions:

[0005] A self-locking structure for preventing the secondary box of a transmission from falling out of gear includes a self-locking valve. The self-locking valve includes a valve body, in which a plug, a spring and a top pin are sequentially installed from top to bottom. One end of the spring is connected to the lower end of the plug, and the other end is connected to the upper end of the top pin;

[0006] At the inner wall of the valve body where it cooperates with the top pin, a shoulder is pre-machined, and at the middle of the top pin, a stepped surface is pre-machined, and the stepped surface cooperates with the shoulder;

[0007] The area where the spring is located is the upper air chamber, and the cavity between the stepped surface of the top pin and the shoulder surface of the valve body is the lower air chamber; an upper exhaust hole is opened in the top pin, and a lower exhaust hole is opened at the lower part of the valve body. The upper air chamber is connected to the lower air chamber through the upper exhaust hole, and the lower air chamber is connected to the outside of the valve body through the lower exhaust hole;

[0008] The self-locking valve is installed on the rear cover housing of the gearbox. The secondary box of the gearbox includes a secondary box cylinder, and a secondary box shift fork shaft is provided in the secondary box cylinder; the lower end of the top pin acts on the secondary box shift fork shaft or a self-locking block. The self-locking block is arranged on the secondary box shift fork shaft, and a first groove, a second groove and a third groove are opened on the secondary box shift fork shaft or the self-locking block;

[0009] When the self-locking valve contacts the first groove, the transmission works in the low gear range; when the self-locking valve contacts the second groove, the transmission performs parking power take-off work; when the self-locking valve contacts the third groove, the transmission works in the high gear range.

[0010] Further, the upper exhaust hole includes an axial hole and one or more radial holes penetrating the axial hole, and the lower exhaust hole includes one or more radial holes.

[0011] Furthermore, the radial holes of the upper exhaust hole and the radial holes of the lower exhaust hole are staggered or overlapped in position.

[0012] Furthermore, the ends of the plug and the ejector pin connected to the spring are both small column ends.

[0013] Furthermore, the front end of the ejector pin is hemispherical.

[0014] Furthermore, a screw hole is opened on the upper part of the valve body, and the valve body is fastened to the transmission case by screws.

[0015] Furthermore, the plug is threadedly connected to the valve body.

[0016] Furthermore, a sealing gasket is provided at the connection between the upper end of the plug and the valve body.

[0017] Furthermore, a sealing groove for installing a sealing ring is opened on the outer circumferential surface of the valve body.

[0018] Compared with the prior art, the present invention has the following beneficial technical effects:

[0019] The present invention discloses a self-locking structure for preventing a transmission auxiliary box from falling out of gear, including a self-locking valve, which includes a valve body. A plug, a spring and a push pin are installed in the valve body from top to bottom in sequence, one end of the spring is connected to the plug, and the other end is connected to the push pin. A shoulder is pre-processed at the inner wall where the valve body and the push pin cooperate, and a step surface is pre-processed at the middle of the push pin. The step surface cooperates with the shoulder to prevent the push pin from falling out of the valve body; the area where the spring is located is an upper air cavity, and the cavity between the push pin step surface and the valve body shoulder surface is a lower air cavity. The upper air cavity is connected with the lower air cavity through an upper exhaust hole opened in the push pin, and the lower air cavity is connected with the outside of the self-locking valve through a lower exhaust hole opened in the lower part of the valve body. The through design of the exhaust hole and the air cavity avoids poor exhaust inside the valve body or formation of a dead cavity, which causes the push pin to be unable to move axially smoothly. The front end of the top pin acts on the auxiliary box fork shaft or the self-locking block. The auxiliary box fork shaft or the self-locking block is provided with the first groove, the second groove and the third groove. When the self-locking valve contacts the first groove, the transmission works in the low gear area; when the self-locking valve contacts the second groove, the transmission performs parking power take-off; when the self-locking valve contacts the third groove, the transmission works in the high gear area. The self-locking valve has a corresponding groove for each working state, thus reducing the probability of gear drop during the working process and ensuring the reliability of the transmission.

[0020] Furthermore, one end of the spring is pressed and loosely sleeved on the small column end of the ejector pin, and the other end is pressed and loosely sleeved on the small column end of the plug. The two small column ends support the spring and prevent it from tilting, thereby increasing the service life of the spring.

[0021] Further, a sealing groove for installing a sealing ring is formed on the outer circle of the valve body to ensure the sealing performance and prevent the transmission oil from flowing out of the valve body installation position. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 FIG. is a schematic structural diagram of the self-locking valve of the present invention;

[0023] Figure 2 is Figure 1 A-A cross-sectional view of;

[0024] Figure 3 is Figure 2 A schematic structural diagram of another state of;

[0025] Figure 4 FIG. is a schematic structural diagram of Application Example 1 of the self-locking valve of the present invention;

[0026] Figure 5 FIG. is a schematic structural diagram of Application Example 2 of the self-locking valve of the present invention.

[0027] Wherein: 1 is the self-locking valve; 2 is the transmission rear cover housing; 3 is the auxiliary box cylinder; 301 is the piston; 302 is the piston group; 4 is the self-locking block; 5 is the auxiliary box fork; 6 is the auxiliary box fork shaft;

[0028] 101 is the valve body; 102 is the plug; 103 is the gasket; 104 is the sealing ring; 105 is the spring; 106 is the top pin; 107 is the upper exhaust hole, 108 is the lower exhaust hole, 109 is the screw hole, 110 is the lower air cavity, 111 is the upper air cavity. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] The present invention will be further described in detail below with reference to the accompanying drawings:

[0030] Such as Figure 1As shown in the figure, the present invention discloses a self-locking structure for preventing the secondary gearbox of a transmission from falling out of gear. The self-locking valve 1 includes a valve body 101. Inside the valve body 101, a plug 102, a spring 105, and a top pin 106 are sequentially installed from top to bottom. One end of the spring 105 is connected to the lower end of the plug 102, and the other end is connected to the upper end of the top pin 106. At the inner wall of the valve body 101 that cooperates with the top pin 106, a shoulder is pre-machined. At the middle part of the top pin 106, a stepped surface is pre-machined, and the stepped surface cooperates with the shoulder. A lower exhaust hole 108 is opened at the lower part of the valve body 101, and an upper exhaust hole 107 is opened inside the top pin 106. The area where the spring 105 is located is the upper air chamber 111, and the cavity between the stepped surface of the top pin 106 and the shoulder surface of the valve body 101 is the lower air chamber 110. The upper air chamber 111 is connected to the lower air chamber 110 through the upper exhaust hole 107, and the lower air chamber 110 is connected to the outside of the self-locking valve 1 through the lower exhaust hole 108. The front end of the top pin 106 acts on the secondary gearbox shift fork shaft 6. The top pin 106 and the inner wall of the valve body 101 are in clearance fit to ensure that the top pin 106 can move smoothly axially in the inner hole of the valve body 101. The design of the exhaust hole avoids the situation of poor exhaust or the formation of a dead cavity, which may cause the top pin 106 to not move smoothly axially.

[0031] The self-locking valve 1 of the present invention is an integral structure, which is more convenient for maintenance. For the existing self-locking valve 1 structure, if the cylinder needs to be disassembled due to a spring 105 failure, the rear secondary gearbox assembly needs to be disassembled, and then the transmission needs to be removed from the vehicle, and its maintenance difficulty is extremely high. However, for the present invention, only the self-locking valve 1 needs to be disassembled, and there is no need to disassemble the cylinder, with small maintenance difficulty, and it also saves the user's maintenance time and cost.

[0032] The inside of the valve body 101 is a cavity, and a shoulder is pre-machined at the inner wall that cooperates with the top pin 106. At the middle part of the top pin 106, a stepped surface is pre-machined, and the stepped surface cooperates with the shoulder to prevent the top pin 106 from being disengaged from the valve body 101.

[0033] One end of both the plug 102 and the top pin 106 connected to the spring 105 is a small column end. One end of the spring 105 is pressed and loosely sleeved on the small column end of the top pin 106, and the other end is pressed and loosely sleeved on the small column end of the plug 102. The two small column ends support the spring 105 and prevent it from tilting, which can improve the service life of the spring 105.

[0034] The lower end of the top pin 106 is hemispherical, and the middle part is cylindrical. Generally, if the size of the spherical top pin exposed outside the valve body is greater than its radius, it is very easy to be disengaged. Therefore, its working stroke will not be greater than the radius of the sphere. However, for the top pin 106 used in the present invention, the lower end is hemispherical, and the upper end relies on the stepped surface to cooperate with the shoulder of the valve body 101 to prevent it from being disengaged. The size of the top pin 106 exposed outside the valve body 101 can be greater than the radius of the lower hemispherical part. Therefore, the working stroke of the self-locking valve 1 of the present invention can be greater than that of the top pin 106 with the same radius of the sphere.

[0035] The upper part of the valve body 101 is provided with screw holes 109, and the valve body 101 is fastened to the rear cover housing of the transmission by screws.

[0036] The plug 102 is threadedly connected to the valve body 101, and a gasket 103 is provided at the connection between the upper end of the plug 102 and the valve body 101.

[0037] A sealing groove for installing the sealing ring 104 is provided on the outer circle of the valve body 101 to ensure the sealing performance and prevent the transmission oil from flowing out of the installation position of the valve body 101.

[0038] Such as Figure 2 and 3 As shown, the upper exhaust hole 107 includes an axial hole and one or more radial holes communicating with the axial hole, and the lower exhaust hole 108 includes one or more radial holes. The positions of the radial holes of the upper exhaust hole 107 and the lower exhaust hole 108 can be staggered or coincident.

[0039] Such as Figure 4 As shown, the self-locking valve 1 is installed on the rear cover housing of the transmission. The auxiliary box of the transmission includes an auxiliary box cylinder 3. An auxiliary box fork shaft 6 is provided in the auxiliary box cylinder 3. A self-locking block 4 is provided on the auxiliary box fork shaft 6. The self-locking block 4 is provided with three grooves, which are the first groove, the second groove and the third groove in sequence from left to right. A boss is formed between adjacent grooves. The self-locking block 4 is fixedly connected to the auxiliary box fork shaft 6 by a pin. Adding the self-locking block 4 does not require any change to the auxiliary box fork shaft 6 and does not affect the original transmission structure. When the grooves on the self-locking block 4 are worn, the self-locking block 4 can be directly replaced, which can greatly save costs.

[0040] One end of the auxiliary box fork shaft 6 located in the auxiliary box cylinder 3 is connected with a piston 301. A piston group 302 is also provided in the auxiliary box cylinder 3. The auxiliary box cylinder 3 and the piston 301 and the piston group 302 form an L chamber, an H chamber and an M chamber communicating with the external air circuit.

[0041] When the L chamber intakes air, the piston 301 moves to the rightmost side. The piston 301 drives the auxiliary box fork shaft 6 and the auxiliary box fork 5 to move to the rightmost side, thereby driving the transmission to shift to a low gear. The self-locking valve 1 contacts the first groove of the self-locking block 4. At this time, the transmission works in the low gear range.

[0042] When the H chamber intakes air, the piston 301 moves to the leftmost side. The piston 301 drives the auxiliary box fork shaft 6 and the auxiliary box fork 5 to move to the leftmost side, thereby driving the transmission to shift to a high gear. The self-locking valve 1 contacts the third groove of the self-locking block 4. At this time, the transmission works in the high gear range.

[0043] When parking power take-off is performed, air enters the M chamber when the auxiliary box is in low gear. The piston group 302 pushes the auxiliary box fork shaft 6, driving the piston 301 and the auxiliary box fork 5 to move to the middle position. That is to say, the auxiliary box fork 5 is pushed to the middle position of shifting between high and low gears. The self-locking valve 1 contacts the second groove of the self-locking block 4. At this time, the power transmission route of the transmission output shaft is interrupted, preparing for the parking power take-off operation of the transmission.

[0044] For each working state, the self-locking valve 1 has a corresponding groove, so the probability of gear dropping during the working process can be reduced, ensuring the reliability of the transmission operation.

[0045] If the exhaust is difficult when the top pin 106 moves from the groove to the boss, it is easy to cause difficulty in moving the auxiliary box fork shaft 6, and further cause slow shifting or even inability to shift in the auxiliary box; if the exhaust is difficult when the top pin 106 moves from the boss to the groove, the self-locking function cannot be realized. Therefore, the present invention designs an exhaust hole to solve the problem that the top pin 106 cannot move axially smoothly due to poor exhaust or the formation of a dead cavity.

[0046] As Figure 5 shown, the self-locking block 4 may not be provided on the auxiliary box fork shaft 6, and the groove is directly provided on the auxiliary box fork shaft 6. Its working process is the same as that of the Figure 1 structure shown, except that the axial height of the valve body 101 is increased and the axial height of the top pin 106 is lengthened.

Claims

1. A self-locking structure for preventing the secondary box of a transmission from falling out of gear, characterized in that, It includes a self-locking valve (1), and the self-locking valve (1) includes a valve body (101). Inside the valve body (101), a plug (102), a spring (105) and a top pin (106) are successively installed from top to bottom. One end of the spring (105) is connected to the lower end of the plug (102), and the other end is connected to the upper end of the top pin (106). At the inner wall of the valve body (101) that cooperates with the top pin (106), a shoulder is pre-machined. At the middle of the top pin (106), a stepped surface is pre-machined, and the stepped surface cooperates with the shoulder. The area where the spring (105) is located is the upper air chamber (111), and the cavity between the stepped surface of the top pin (106) and the shoulder surface of the valve body (101) is the lower air chamber (110). An upper exhaust hole (107) is opened in the top pin (106), and a lower exhaust hole (108) is opened at the lower part of the valve body (101). The upper air chamber (111) is connected to the lower air chamber (110) through the upper exhaust hole (107), and the lower air chamber (110) is connected to the outside of the valve body (101) through the lower exhaust hole (108). The self-locking valve (1) is installed on the rear cover housing of the gearbox. The auxiliary box of the gearbox includes an auxiliary box cylinder (3), and an auxiliary box shift fork shaft (6) is provided in the auxiliary box cylinder (3). The lower end of the top pin (106) acts on the auxiliary box shift fork shaft (6) or a self-locking block (4). The self-locking block (4) is arranged on the auxiliary box shift fork shaft (6), and a first groove, a second groove and a third groove are opened on the auxiliary box shift fork shaft (6) or the self-locking block (4). When the self-locking valve (1) contacts the first groove, the transmission works in the low gear range; when the self-locking valve (1) contacts the second groove, the transmission performs parking power take-off work; when the self-locking valve (1) contacts the third groove, the transmission works in the high gear range.

2. The self-locking structure for preventing the secondary box of the transmission from falling out of gear according to claim 1, characterized in that, The upper exhaust hole (107) includes an axial hole and one or more radial holes that penetrate the axial hole. The lower exhaust hole (108) includes one or more radial holes.

3. The self-locking structure for preventing the secondary box of the transmission from slipping out of gear according to claim 2, characterized in that, The radial holes of the upper exhaust hole (107) and the radial holes of the lower exhaust hole (108) are staggered or coincident in position.

4. The self-locking structure for preventing the secondary box of the transmission from slipping out of gear according to claim 1, characterized in that, One ends of the plug (102) and the top pin (106) connected to the spring (105) are both small column ends.

5. The self-locking structure for preventing the secondary box of the transmission from falling out of gear according to claim 1, wherein, The front end of the top pin (106) is hemispherical.

6. The self-locking structure for preventing the secondary box of the transmission from shifting out of gear according to claim 1, characterized in that, A screw hole (109) is opened at the upper part of the valve body (101), and the valve body (101) is fastened to the rear cover housing of the gearbox by screws.

7. The self-locking structure for preventing the secondary box of the transmission from falling out of gear according to claim 1, characterized in that, The plug (102) is threadedly connected to the valve body (101).

8. The self-locking structure for preventing the secondary box of the transmission from slipping out of gear according to claim 1, characterized in that, A sealing gasket (103) is provided at the connection between the upper end of the plug (102) and the valve body (101).

9. The self-locking structure for preventing the auxiliary box of a transmission from slipping out of gear according to claim 1, characterized in that, A sealing groove for installing a sealing ring (104) is opened on the outer circular surface of the valve body (101).

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