Automobile transmission shift mechanism for preventing reverse gear from rattling

Abstract

The present invention relates to a gearshift mechanism for a car transmission for preventing reverse gear from hitting gears, comprising a gearshift shaft, a first and second gear shift fork tail, a pre-hanging arm fixedly arranged at the first and second gear shift fork tail, the pre-hanging arm being parallel to the first and second gear shift fork tail, a fixing seat fixedly arranged on the shift fork shaft, the fixing seat being connected to the camshaft through a limit pin, a gap being reserved between the limit pin and the camshaft for the camshaft to rotate and return, an overhanging end of the camshaft being fixedly connected to the pre-hanging cam, the pre-hanging cam corresponding to the pre-hanging arm, a return spring sleeved on the camshaft, one end of the return spring being connected and fixed to the pre-hanging cam, and the other end of the return spring being connected and fixed to the fixing seat, the fifth reverse gear shift fork tail, the third and fourth gear shift fork tail, and the first and second gear shift fork tail being arranged in sequence along the axial direction of the gearshift shaft, a gearshift dial head fixedly arranged on the gearshift shaft, the gearshift dial head comprising shift teeth and a shifting head, the shifting head corresponding to the fork openings of each shift fork tail, the distance from the fork opening of the fifth reverse gear shift fork tail to the pre-hanging arm is the same as the distance from the shifting head of the gearshift dial head to the pre-hanging cam along the axial direction.

Description

Technical Field

[0001] The invention relates to the field of automobile transmissions, and in particular to an automobile transmission shift mechanism for preventing reverse gear from playing. Background Art

[0002] At present, most of the automobile transmission shift mechanisms do not have a reverse synchronizer, but directly achieve reverse gear by sliding engagement between the input shaft spur gear and the reverse gear spur gear. Therefore, when the car is quickly engaged in reverse gear without being turned off, the input shaft spur gear will have a certain rotation speed and cannot smoothly engage with the reverse gear spur gear, resulting in the situation of gear hitting when engaging reverse gear, which generates impact and produces a scraping sound, affecting the driving comfort of the driver. At present, there are also ways to solve the reverse gear hitting problem by adding a reverse synchronizer or a lever synchronizer, but the reverse synchronizer or the lever synchronizer requires the use of reverse gear ring, reverse gear fork and other parts, which not only increases the cost, but also increases the complexity of the transmission structure, making the transmission assembly difficult and reducing the transmission assembly efficiency. Summary of the invention

[0003] The purpose of the present invention is to provide a car transmission shift mechanism that prevents reverse gear from rattling in view of the deficiencies in the prior art. The pre-engagement can be achieved by setting a pre-engagement arm to decelerate the spur gear of the input shaft, thereby solving the problem of reverse gear rattling. At the same time, the structure is simple, which simplifies the assembly of the transmission.

[0004] The technical solution of the present invention is: a kind of automobile transmission shift mechanism that prevents reverse gear from playing gear, comprising a shift shaft, and a five-reverse gear shift fork shaft, a three-fourth gear shift fork shaft, and a first and second gear shift fork shaft arranged in parallel with each other, the five-reverse gear shift fork tail and the five-reverse gear shift fork head are fixedly installed on the five-reverse gear shift fork shaft, the three-fourth gear shift fork tail and the three-fourth gear shift fork head are fixedly installed on the three-fourth gear shift fork shaft, the first and second gear shift fork tail and the first and second gear shift fork head are fixedly installed on the first and second gear shift fork shaft, the five-reverse gear shift fork tail, the three-fourth gear shift fork tail, and the first and second gear shift fork tail are respectively provided with fork openings, the first and second gear shift fork tail is fixedly provided with a pre-hanging arm, the pre-hanging arm is parallel to the first and second gear shift fork tail, a fixing seat is fixedly installed on the shift shaft, the fixing seat is connected to a camshaft through a limit pin, the camshaft and the fixing seat are clearance-matched, and the limit pin and the camshaft are spaced apart. A gap is left for the camshaft to rotate and return to its original position, and the extended end of the camshaft is fixedly connected to a pre-hanging cam, and the pre-hanging cam corresponds to the pre-hanging arm, and a return spring is sleeved on the camshaft, one end of the return spring is connected and fixed to the pre-hanging cam, and the other end of the return spring is connected and fixed to the fixed seat, and the fifth reverse gear shift fork tail, the third and fourth gear shift fork tails, and the first and second gear shift fork tails are arranged in sequence along the axial direction of the shift shaft, and a shift dial head is fixedly installed on the shift shaft, and the shift dial head includes shift teeth and a shift head, and the shift head corresponds to the fork of the fifth reverse gear shift fork tail, the third and fourth gear shift fork tail, and the first and second gear shift fork tail, and is used for sliding into the fork of the corresponding gear shift fork tail through the axial movement of the shift shaft to shift, and the distance from the fork of the fifth reverse gear shift fork tail to the pre-hanging arm is the same as the distance from the shift dial head to the pre-hanging cam along the axial direction.

[0005] A shifting notch is provided at the lower part of the extended end of the pre-hanging arm for facilitating the shifting force of the pre-hanging cam.

[0006] The pre-hanging arm and the first and second gear shift fork tails are fixed by integral molding.

[0007] The pre-hanging cam is fixed to the camshaft by interference fit.

[0008] The camshaft is provided with a limiting groove, and the limiting pin cooperates with the limiting groove to form axial fixation and circumferential limiting of the camshaft.

[0009] The above technical scheme is adopted: it includes a shift shaft, and a five-reverse gear shift fork shaft, a three-fourth gear shift fork shaft, and a first and second gear shift fork shaft which are arranged parallel to each other, the five-reverse gear shift fork tail and the five-reverse gear shift fork head are fixedly installed on the five-reverse gear shift fork shaft, the three-fourth gear shift fork tail and the three-fourth gear shift fork head are fixedly installed on the three-fourth gear shift fork shaft, the first and second gear shift fork tail and the first and second gear shift fork head are fixedly installed on the first and second gear shift fork shaft, the five-reverse gear shift fork tail, the three-fourth gear shift fork tail, and the first and second gear shift fork tail are respectively provided with fork openings, the first and second gear shift fork tail is fixedly provided with a pre-hanging arm, the pre-hanging arm is parallel to the first and second gear shift fork tail, a fixing seat is fixedly installed on the shift shaft, the fixing seat is connected to a camshaft through a limit pin, the camshaft and the fixing seat are clearance-matched, and a space is left between the limit pin and the camshaft for the camshaft to rotate back to its original position The camshaft has a pre-hanging cam fixedly connected to the outwardly extending end thereof, and the pre-hanging cam corresponds to the pre-hanging arm; a return spring is sleeved on the camshaft, one end of the return spring is connected and fixed to the pre-hanging cam, and the other end of the return spring is connected and fixed to the fixing seat; the fifth and reverse gear shift fork tail, the third and fourth gear shift fork tail, and the first and second gear shift fork tail are arranged in sequence along the axial direction of the shift shaft; a shift dial head is fixedly installed on the shift shaft, and the shift dial head includes shift teeth and a shift head, and the shift dial head corresponds to the fork of the fifth and reverse gear shift fork tail, the third and fourth gear shift fork tail, and the first and second gear shift fork tail, and is used for sliding into the fork of the corresponding gear shift fork tail through the axial movement of the shift shaft to shift; the distance from the fork of the fifth reverse gear shift fork tail to the pre-hanging arm is the same as the distance from the shift dial head to the pre-hanging cam along the axial direction. When engaging reverse gear, the shift shaft is moved axially to move the shift head of the shift lever to the fork of the fifth reverse gear fork tail. Since the distance from the fork of the fifth reverse gear fork tail to the pre-engagement arm is the same as the distance from the shift head of the shift lever to the pre-engagement cam along the axial direction, the pre-engagement cam is just below the pre-engagement arm. Then the shift shaft is rotated through the shift teeth of the shift lever to make the shift head of the shift lever move the fifth reverse gear fork tail, and the fifth reverse gear fork shaft will drive the fifth reverse gear fork head to move axially together, thereby achieving reverse gear. At the same time, when the shift head shifts the tail of the fifth reverse gear shift fork, the shift shaft will also drive the pre-engagement cam to rotate together. When the pre-engagement cam contacts the shift arm, the pre-engagement cam will rotate a certain angle relative to the fixed seat to compress the return spring until the camshaft is restricted by the limit pin and stops. At this time, the pre-engagement cam will start to shift the pre-engagement arm, so that the first and second gear shift fork shafts drive the first and second gear shift fork heads to move together, realize the second gear pre-engagement, and reduce the speed of the spur gear of the input shaft. The decelerated spur gear can smoothly mesh with the reverse gear spur gear, avoiding the occurrence of impact and noise, solving the problem of reverse gear hitting, and also improving the driving comfort of the driver and increasing market competitiveness. At the same time, the mechanism is also simple and stable, and the reverse gear can be smoothly engaged without using reverse gear rings, reverse gear forks and other parts, which reduces costs, simplifies the assembly of the transmission, and improves production efficiency.

[0010] The lower part of the extended end of the pre-hanging arm is provided with a shifting notch for facilitating the shifting force of the pre-hanging cam. The shifting notch is easy to process, and also facilitates the shifting force of the pre-hanging cam, thereby improving the stability of the shifting of the pre-hanging cam.

[0011] The pre-hanging arm and the first and second gear shift fork tail are fixed by integral molding, the integral molding is simple to process, and the connection between the pre-hanging arm and the first and second gear shift fork tail is also stable.

[0012] The pre-engaging cam is fixed to the camshaft by interference fit, and the interference fit connection is simple, while also avoiding relative rotation between the pre-engaging cam and the camshaft.

[0013] The camshaft is provided with a limiting groove, and the limiting pin cooperates with the limiting groove to form axial fixation and circumferential limiting of the camshaft. Through the cooperation of the limiting pin and the limiting groove, the limiting of the camshaft is simple and effective, that is, the effective connection between the camshaft and the fixing seat is ensured, and the small angle rotation of the camshaft relative to the fixing seat is also realized. The angle of limiting the rotation of the camshaft can be controlled by the gap between the limiting pin and the camshaft limiting groove.

[0014] The automobile transmission shift mechanism for preventing the reverse gear from rattling is simple and stable, simplifies the assembly of the transmission, improves production efficiency and reduces costs. At the same time, the decelerated spur gear can smoothly mesh with the reverse gear spur gear, avoiding the occurrence of impact and noise, and solving the problem of reverse gear rattling.

[0015] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the present invention;

[0017] Figure 2 for Figure 1 A magnified view of;

[0018] Figure 3 This is a schematic diagram of the structure of the first and second gear shift fork tail;

[0019] Figure 4 This is a schematic diagram of the coordination between the pre-hook cam and the camshaft.

[0020] In the attached drawings, 1 is the shift head, 1-1 is the shift tooth, 1-2 is the shift head, 2 is the shift shaft, 3 is the fixed seat, 4 is the limit pin, 5 is the pre-hanging cam, 6 is the fifth and reverse gear shift fork tail, 6-1 is the fork mouth, 7 is the third and fourth gear shift fork tail, 8 is the first and second gear shift fork tail, 9 is the pre-hanging arm, 9-1 is the shifting notch, 10 is the third and fourth gear shift fork shaft, 11 is the fifth and reverse gear shift fork shaft, 12 is the first and second gear shift fork shaft, 13 is the first and second gear shift fork head, 14 is the return spring, 15 is the camshaft, and 15-1 is the limit groove. DETAILED DESCRIPTION

[0021] See also Figures 1 to 4, a shift mechanism for a car transmission that prevents reverse gear from hitting gears, comprising a shift shaft 2, and a fifth-reverse gear fork shaft 11, a third- and fourth-gear fork shaft 10, and a first- and second-gear fork shaft 12 that are arranged in parallel with each other. The fifth-reverse gear fork tail 6 and the fifth-reverse gear fork head are fixedly mounted on the fifth-reverse gear fork shaft 11; the third- and fourth-gear fork tail 7 and the third- and fourth-gear fork head are fixedly mounted on the third- and fourth-gear fork shaft 10; the first- and second-gear fork tail 8 and the first- and second-gear fork head 13 are fixedly mounted on the first- and second-gear fork shaft 12. The fifth-reverse gear fork tail 6, the third- and fourth-gear fork tail 7, and the first- and second-gear fork tail 8 are respectively provided with two fork arms, and a fork opening is provided between the two fork arms of each fork tail. The first- and second-gear fork tail 8 is integrally formed and fixed with a pre-hanging arm 9, and the integrally formed processing is simple, and the connection between the pre-hanging arm 9 and the first- and second-gear fork tail 8 is also stable. The pre-hanging arm 9 is located on one side of the first and second gear shift fork tail 8 and is parallel to the first and second gear shift fork tail 8. The pre-hanging arm 9 and the upper fork arm of the first and second gear shift fork tail 8 are located in the same horizontal plane. A fixing seat 3 is fixedly installed on the shift shaft 2. The fixing seat 3 is provided with a hole that matches the shift shaft 2. The fixing seat 3 and the shift shaft 2 can be positioned and installed by a pin. One end of the fixing seat 3 extends through a limit pin 4 to connect a camshaft 15. The camshaft 15 is clearance-matched with the fixing seat 3. A clearance is left between the limit pin 4 and the camshaft 15 for the camshaft 15 to rotate back to its original position. The camshaft 15 is provided with a limit groove 15-1. The limit pin 4 cooperates with the limit groove 15-1 of the camshaft 15 to form axial fixation and circumferential limitation of the camshaft 15. Through the cooperation of the limit pin 4 and the limit groove 15-1, the limit of the camshaft 15 is simple and effective, that is, the effective connection between the camshaft 15 and the fixed seat 3 is ensured, and the small angle rotation of the camshaft 15 relative to the fixed seat 3 is also realized. The rotation angle of the camshaft 15 can be controlled by the gap left between the limit pin 4 and the limit groove 15-1 of the camshaft 15. The extended end of the camshaft 15 is interference-fitted to fix a pre-hanging cam 5. The interference fit connection is simple and also avoids the relative rotation between the pre-hanging cam 5 and the camshaft 15. The pre-hanging cam 5 corresponds to the pre-hanging arm 9. The lower part of the extended end of the pre-hanging arm 9 is provided with a shifting notch 9-1 that is convenient for the pre-hanging cam 5 to be shifted and applied. The shifting notch 9-1 is simple to process, and it is also convenient for the pre-hanging cam 5 to be shifted and applied, and the stability of the pre-hanging cam 5 to be shifted is improved. A return spring 14 is sleeved on the camshaft 15, one end of the return spring 14 is connected and fixed to the pre-engaging cam 5, and the other end of the return spring 14 is connected and fixed to the fixing seat 3. The return spring 14 is mainly used to drive the pre-engaging cam 5 to return. The fifth and reverse gear shift fork tail 6, the third and fourth gear shift fork tail 7, and the first and second gear shift fork tail 8 are arranged in sequence along the axial direction of the shift shaft 2, and the plane formed by the two fork arms of each shift fork tail is perpendicular to the shift shaft 2. A shift dial head 1 is fixedly installed on the shift shaft 2, and the shift dial head 1 includes a shift tooth 1-1 and a shift head 1-2, and the shift tooth 1-1 and the shift head 1-2 are located on the same diameter line of the shift shaft 2.The shift head 1-2 corresponds to the fork of the fifth and reverse gear shift fork tail 6, the third and fourth gear shift fork tail 7, and the first and second gear shift fork tail 8, and is used to slide into the fork of the corresponding gear shift fork tail through the axial movement of the shift shaft 2 to shift gears. The distance from the fork 6-1 of the fifth and reverse gear shift fork tail 6 to the pre-hanging arm 9 is the same as the distance from the shift head 1-2 of the shift head 1 to the pre-hanging cam 5 along the axial direction of the shift shaft 2.

[0022] When engaging the reverse gear, the shift shaft 2 is axially moved to move the shift head 1-2 of the shift head 1 to the fork 6-1 of the fifth reverse gear fork tail 6. Since the distance from the fork 6-1 of the fifth reverse gear fork tail 6 to the pre-engagement arm 9 is the same as the distance from the shift head 1-2 of the shift head 1 to the pre-engagement cam 5 along the axial direction, the pre-engagement cam 5 is just located below the pre-engagement arm 9. Then, the shift shaft 2 is rotated by the shift teeth 1-1 of the shift head 1 to make the shift head 1-2 of the shift head 1 move the fifth reverse gear fork tail 6, and the fifth reverse gear fork shaft 11 will drive the fifth reverse gear fork head to move axially together, thereby achieving the reverse gear engagement. At the same time, when the shift head 1-2 shifts the fifth reverse gear shift fork tail 6, the shift shaft 2 will also drive the pre-engagement cam 5 to rotate together. When the pre-engagement cam 5 contacts the shift arm 9, the pre-engagement cam 5 will rotate a small angle relative to the fixed seat 3 to compress the return spring until the camshaft 15 is restricted by the limit pin 4 and then stops. At this time, the pre-engagement cam 5 will start to shift the pre-engagement arm 9, so that the first and second gear shift fork shaft 12 drives the first and second gear shift fork head 13 to move together, realize the second gear pre-engagement, and reduce the speed of the spur gear of the input shaft. The decelerated spur gear can mesh smoothly with the reverse gear spur gear, avoiding the occurrence of impact and noise, solving the problem of reverse gear tooth collision, and also improving the driving comfort of the driver and increasing market competitiveness. After the second gear pre-engagement is completed, the apex of the free end of the pre-engagement cam 5 passes over the end of the pre-engagement arm 9 and is separated from the pre-engagement arm 9. At this time, the pre-engagement cam 5 can be returned to its original position through the elastic recovery of the return spring 14, and the shift shaft 2 will move axially when the reverse gear returns to the neutral gear, staggering the pre-engagement cam 5 and the pre-engagement arm 9, so as to realize the reverse gear returning to the neutral gear. When the shift mechanism changes to other gears except the reverse gear, the pre-engagement cam 5 in the structure will not contact the pre-engagement arm 9 on the tail 8 of the first and second gear shift fork, and the shift mechanism can ensure smooth shifting between various gears. Moreover, the mechanism is also simple and stable, and can realize smooth reverse gear engagement without using parts such as the reverse gear ring and the reverse gear fork, thereby reducing costs, simplifying the assembly of the transmission, and improving production efficiency.

Claims

1. A shift mechanism for a car transmission for preventing reverse gear from hitting gears, comprising a shift shaft (2), and a fifth reverse gear shift fork shaft (11), a third and fourth gear shift fork shaft (10), and a first and second gear shift fork shaft (12) arranged in parallel with each other, wherein the fifth reverse gear shift fork tail (6) and the fifth reverse gear shift fork head are fixedly mounted on the fifth reverse gear shift fork shaft (11), the third and fourth gear shift fork tail (7) and the third and fourth gear shift fork head are fixedly mounted on the third and fourth gear shift fork shaft (10), the first and second gear shift fork tail (8) and the first and second gear shift fork head (13) are fixedly mounted on the first and second gear shift fork shaft (12), the fifth reverse gear shift fork tail (6), the third and fourth gear shift fork tail (7), and the first and second gear shift fork tail (8) are respectively provided with fork openings, characterized in that: The first and second gear shift fork tail (8) is fixedly provided with a pre-hanging arm (9), the pre-hanging arm (9) is located on one side of the first and second gear shift fork tail (8) and is parallel to the first and second gear shift fork tail (8), the pre-hanging arm (9) and the upper fork arm of the first and second gear shift fork tail (8) are located in the same horizontal plane, the pre-hanging arm (9) and the first and second gear shift fork tail (8) are fixed by integral molding, a fixing seat (3) is fixedly installed on the shift shaft (2), the fixing seat (3) is connected to a camshaft (15) via a limit pin (4), and the camshaft (15) is clearance-matched with the fixing seat (3), a clearance is left between the limiting pin (4) and the camshaft (15) for the camshaft (15) to rotate back to its original position, the camshaft (15) is provided with a limiting groove (15-1), the limiting pin (4) and the limiting groove (15-1) cooperate to form axial fixation and circumferential limitation of the camshaft (15), the extended end of the camshaft (15) is fixedly connected to a pre-hanging cam (5), the pre-hanging cam (5) corresponds to the pre-hanging arm (9), and the pre-hanging arm (9) The lower part of the extended end is provided with a shifting notch (9-1) for facilitating the shifting force of the pre-engaging cam (5); a return spring (14) is sleeved on the camshaft (15); one end of the return spring (14) is connected and fixed to the pre-engaging cam (5); the other end of the return spring (14) is connected and fixed to the fixing seat (3); the fifth and reverse gear shift fork tail (6), the third and fourth gear shift fork tail (7), and the first and second gear shift fork tail (8) are arranged in sequence along the axial direction of the shift shaft (2); and a shifting fork is fixedly installed on the shift shaft (2). A shifting head (1), the shifting head (1) comprising shifting teeth (1-1) and a shifting head (1-2), the shifting head (1-2) corresponding to the forks of a fifth-reverse gear shift fork tail (6), a third- and fourth-gear shift fork tail (7), and a first- and second-gear shift fork tail (8), and used for shifting by sliding into the forks of the corresponding gear shift fork tails through axial movement of a shifting shaft (2), the distance from the fork of the fifth-reverse gear shift fork tail (6) to a pre-hanging arm (9) being the same as the distance from the shifting head (1-2) of the shifting head (1) to a pre-hanging cam (5) along the axial direction.

2. The automobile transmission shift mechanism for preventing reverse gear play according to claim 1, characterized in that: The pre-hanging cam (5) is fixed to the cam shaft (15) by interference fit.

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