JPS624945A - Booster for control of transmission gear - Google Patents

Abstract

PURPOSE:To prevent wear from occurring to the dog teeth of a transmission gear when the synchronous load of a synchro mechanism is rapidly decreased, by a method wherein a buffering means is placed to the piston of the booster of a transmission mechanism. CONSTITUTION:Second and third pistons 8 and 9 are disposed to both sides of a first piston 5 of a booster, and buffering chambers A are respectively formed between the pistons 8, 9 and both ends of a cylinder 3. Valve bodies 14 and 15, introducing and exhausting compressed air in and from between the buffering chambers A, are disposed to an abutment part of the pistons 8 and 9 to the piston 5. When the compressed air is introduced to the one side of the piston 5, the piston 5 is moved. But, in which case, the compressed air incomes to the buffering chambers A through the valve bodies 14 and 15. When the piston 5 is moved, the valve bodies 14 and 15 are opened resulting from collapsion with the piston 5, and a buffering pressure is exerted on the one side of the piston 5.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Industrial Application Field The present invention relates to a booster for operating a transmission for shifting mainly used in automobiles, etc., and particularly to a synchronizing mechanism during shifting of a transmission (when engaging a gear). The present invention relates to a booster that attenuates the shift force of a piston rod in order to prevent the piston rod of the booster from accelerating suddenly due to a sudden decrease in the synchronous load of the booster.

b. Prior art and its problems Operation of a transmission generally requires greater force for shift operation than that of a select device. For this reason, especially in buses and trucks that have large transmissions, a booster is attached to the transmission to enable smooth shifting operations with light force.

By the way, in a so-called synchronous type transmission in which the gears are synchronized and then engaged, a relatively large load for synchronization acts on the booster when the gears are engaged, but the load decreases rapidly after synchronization. For this reason, the piston rod of the booster suddenly accelerates after synchronization, and as a result, there is a risk that an impact will be applied to the dog teeth of the transmission gear, causing wear and a decrease in durability of the dog teeth.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a booster for operating a transmission that can solve the above-mentioned problems.

Means for Solving Problem C8 In order to solve the above-mentioned problem, in the present invention, a first piston is attached to the outer circumferential surface of a hollow piston rod that is slidably disposed in a cylinder. A pair of pressure chambers are formed on both sides of one piston, a pair of supply and exhaust holes are formed in the peripheral wall of the piston rod on both sides of the piston, and a pair of valves are disposed inside the piston rod, By opening and closing an operating rod inserted from one end of the piston rod, compressed air is supplied to and discharged from the pair of pressure chambers through the pair of supply and exhaust holes, thereby operating the piston rod. In the transmission operation booster according to the present invention, second and third pistons are slidably disposed on both sides of the pair of air supply and exhaust holes, and the second and third pistons are connected to both ends of the cylinder. A pair of buffer chambers filled with compressed air are formed between the second and third pistons.
An energizing means for energizing the piston side is provided in the buffer chamber,
The second and third pistons are provided with through holes that communicate with the pair of buffer chambers and the air supply/exhaust hole, and a valve body is fitted and arranged in the through holes, and as the first piston moves, The valve body is pressed by the piston to open the valve, and the buffer chamber and the pressure chamber communicate with each other through a gap between the valve body and the through holes of the second and third pistons. It is configured so that

An embodiment of the present invention will be described below based on the drawings.

1 and 2 show a booster 1 for operating a transmission according to the present invention, and this booster 1 is disposed on a side surface of a transmission (not shown). Housing 2 of booster 1
A cylinder 3 is attached to the cylinder 3, and a piston rod 4 is slidably inserted into the cylinder 3. A first piston 5 having protrusions 5a and 5b on both left and right sides is integrally fixed to the outer peripheral surface of the hollow piston rod 4. They are fitted so that they can slide freely in the direction. Thus, a pair of pressure chambers 6 are provided on both sides of the piston 5,
7 is formed.

Further, a second piston 8 and a third piston 9 are disposed on both sides of the first piston 5, and these pistons 8
．． Buffer chambers A filled with compressed air are formed between the cylinder 9 and both ends of the cylinder 3, respectively. The second and third pistons 8.9 are disposed between the cylinder 3 and the piston rod 4 so as to be slidable along the axial direction of the piston rod 4, and are arranged in recesses 3a and 3b on the inner peripheral side of the cylinder 3.
Compression springs 10 each mounted inside (inside buffer chamber A).
11, the first piston 5 side is always energized.

Note that the movement of these second and third pistons 8.9 toward the first piston 5 is carried out by the recesses 3a,
It is locked by the stopper surface of 3b.

As clearly shown in FIG. 2, the above-mentioned second and third pistons 8
．． 9, a protruding portion 5a of the first piston 5;

A small diameter through hole 12 with a step at a location corresponding to 5b.
, 13 are formed respectively, and valve bodies 14.15 are respectively fitted into these through holes 12.13. These valve bodies 14.15 are always urged toward the first piston 5 by compression springs 16.17, and under normal conditions, the tip of the valve body 14.15 is attached to the second and third pistons. 8.9 protrudes toward the first piston 5 side and closes the through hole 12.13 while facing the protruding portions 5a and 5b of the first piston 5, respectively.

Further, a pair of pressure chambers 6 are provided on the peripheral wall of the piston rod 4.
．． A pair of air supply and exhaust holes 18a and 18b are provided for supplying and discharging compressed air to and from the air conditioner 7.

On the other hand, a conventionally known valve mechanism is housed inside the piston rod 4. As shown in FIGS. 1 and 2, this valve mechanism consists of a pair of left and right fixed valve seats 19.20, and a pair of left and right floating valves 2 disposed inside the fixed valve seats 19.20.
1.22, and a pair of left and right valve lifters 23.24 disposed on the outside of the fixed valve seat 19.20.

A hollow operating rod 25 is inserted into the piston rod 4 so as to be slidable in its axial direction, and one end 26a of an air pipe 26 is flattened at the tip 25a of the operating rod 25. locked in the state. This air pipe 26 is slidably inserted into a pair of pulp lifters 23.24 and an idler valve 21.22, and the compressed air supplied to the compressed air supply port 27 at the end of the piston rod 4 is supplied to the other end 26b of the air pipe 26. From air pipe 26
The air pipe 26 is further introduced into the pair of floating valves 21 and 22 through a through hole 28 formed in the middle portion of the air pipe 26.

Pressing rings 29.30 are attached to the tip end 25a of the operating rod 25 and the other end 26b of the air pipe 26, respectively, and as the operating rod 25 moves, either one of the pressing rings 29.30 is attached to the valve lifter 23 or 24. Press the rear part of one of the idler valves 21.2
It is configured to open 2. In addition, through holes 31.32 are formed in the pair of fixed valve seats 19.20,
These through holes 31, 32 and supply/exhaust holes 18a, 18b
are in communication with each other, and the valve lifters 23 and 24 are in communication with each other.
It also communicates with the outside through the inner periphery.

d. Operation The booster 1 for operating the transmission is configured as described above,
The operating rod 25 is controlled by operating a change lever (not shown).
When the piston is moved in the direction of the arrow a or the direction of the arrow in FIG.

That is, as shown in FIG. 2, when the operating rod 25 is moved, for example, in the direction indicated by the arrow, the valve lifter 23 is pressed by the pressing ring 29 and the floating valve 21 is opened. Idle valve 2
1 opens, the compressed air introduced into the inside of the fixed valve seat 19, 20 flows into the pressure chamber 6 through one air supply/exhaust hole 18a.
This pressure causes the first piston 5 to slide in the direction indicated by the arrow in FIG. Press in the direction.

At this time, the compressed air introduced into the pressure chamber 6 causes the valve body 14 to move back against the compression spring 16 and open the valve, and the buffer chamber A on the second piston 8 side is filled with compressed air. After that, the valve becomes closed.

Thus, the valve body 15 retreats against the biasing force of the compression spring 17, and the through hole 13 of the third piston 9 is released through a small gap. Furthermore, since the protruding portion 5b of the first piston 5 contacts the third piston 9 and attempts to push it in the direction of the arrow against the biasing force of the compression spring 11, the compressed air in the buffer chamber A This pressure acts on the first piston 5 and the piston rod 4 as a load.

At this time, a part of the compressed air in the buffer chamber A passes through the small gap between the valve body 15 and the through hole 13 to the inner periphery of the pressure chamber 7, the supply/exhaust hole 18, the through hole 32, and the valve lifter 24. The piston rod 4 moves to the stroke end position as shown in FIG. Note that at this stroke end position, all of the compressed air in the buffer chamber A is exhausted to the outside, so no force that would cause gear slippage is applied to the first piston 5 and the piston rod 4.

In this way, according to this device, the pressure of the compressed air in the buffer chamber A moves the piston rod 4 while acting as a load on the first piston 5, so that the synchronization load suddenly decreases upon completion of synchronization on the transmission side. Even if there is a problem, the piston rod 4 will not suddenly accelerate, and there is no risk of impact acting on the dog teeth of the transmission gear.

When the change lever is released after the piston rod 4 has completed its shift movement, the operating rod 25 and the valve lifter 23 move in the direction of arrow a from the state shown in FIG. 2, and the idle valve 21 is closed. Further, the compressed air in the pressure chamber 6 passes through the inner peripheral portion of the valve lifter 23 and is discharged to the outside. Note that the buffer chamber A on the second piston 8 side remains filled with compressed air.

=8- When the operating rod 25 is moved in the direction of arrow a from this state, the valve lifter 24 is pressed by the pressure ring 30 to open the floating valve 22, and an operation completely opposite to the above-described operation is performed.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment and can be modified in various ways. For example, in the embodiments described above, compression springs 10 and 11 were used to maintain the volume of the buffer chamber A constant, but they do not necessarily have to be springs, and an elastic material such as rubber may be used as the biasing means. It's okay.

e0 Effects of the Invention As described above, the present invention includes a pair of buffers filled with compressed air, in which second and third pistons each having a valve body fitted into a through hole are disposed on both sides of the first piston. Since a chamber is formed and the valve body is opened as the first piston moves, the pressure of the compressed air in the buffer chamber in the direction in which the first piston moves is equal to the load on the first piston. By acting as a buffer, the shift operation force of the piston rod can be attenuated. As a result, even if there is a sudden decrease in the synchronization load upon completion of synchronization on the transmission side, the piston rod will not suddenly accelerate, and there is no risk of impact acting on the dog teeth of the transmission gear. Therefore, the durability of the transmission gear can be improved.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, in which Fig. 1 is a longitudinal cross-sectional view of a booster for operating a transmission, and Fig. 2 is a view of the piston section in a state where the first piston has completed its shift movement. It is an enlarged sectional view. DESCRIPTION OF SYMBOLS 1... Booster for transmission operation, 3... Cylinder, 4... Hollow piston rod, 5... First piston, 5a, 5b.
...Protrusion, 6.7...Pressure chamber, 8...
Second piston, 9... Third piston, 10, 11.16.17... Compression spring, 12, 13.
...Through hole, 14.15...Valve body, 18a,
18b... Supply/exhaust holes 21, 22... Idle valve, 23.24... Valve lifter 25... Operating rod, 27...
Compressed air supply port, 33... Striker, A
...Buffer room.

Claims (1)

[Claims] A first piston is attached to the outer circumferential surface of a hollow piston rod that is slidably disposed within the cylinder, a pair of pressure chambers are formed on both sides of the first piston, and a circumference of the piston rod on both sides of the piston is formed. A pair of supply and exhaust holes are formed in the face wall, and a pair of valves disposed inside the piston rod are opened and closed by an operating rod inserted from one end of the piston rod. In the transmission operation booster which operates the piston rod by supplying and discharging compressed air to the pair of pressure chambers through the A third piston is slidably disposed, and a pair of buffer chambers filled with compressed air are formed between the second and third pistons and both ends of the cylinder. and a third piston to the first piston.
An energizing means for energizing the piston side is provided in the buffer chamber,
The second and third pistons are provided with through holes that communicate with the pair of buffer chambers and the air supply/exhaust hole, and a valve body is fitted and disposed in the through holes, and as the first piston moves, The valve body is pressed by the piston to open the valve, and the buffer chamber and the pressure chamber communicate with each other through a gap between the valve body and the through holes of the second and third pistons. A booster device for operating a transmission, characterized in that the booster device is configured to operate the transmission.