JP2518005Y2 - Gear shift booster of transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a gear shift booster for a transmission that utilizes fluid pressure to reduce the shift operation force during gear shift.

<Prior Art> In a manually operated transmission, in order to perform a shift change operation with a lighter operating force, a booster utilizing fluid pressure (Japanese Utility Model Publication No. 55-170132 and Japanese Utility Model Publication 55-17).
1632 and Japanese Utility Model Laid-Open No. 57-104038).

Such a booster includes two cylinder chambers which are interposed between a shift lever of a transmission and a link mechanism connected to a control lever of a driver's seat and which are partitioned by a piston. Then, in one of the two cylinder chambers,
Fluid pressure, such as air pressure, is introduced from the air reservoir in response to a shift operation to generate a pressure difference between the cylinder chambers, and the air pressure is applied to the shift lever via the piston to double the shift operation force of the driver. The force is transmitted to the transmission side.

<Problems to be Solved by the Invention> By the way, the air reservoir for supplying air pressure to the booster is used not only for the booster but also for supplying air pressure to the brake system and other in-vehicle devices. . Therefore, since it is necessary to satisfy the required air pressure of all devices, the air pressure in the air reservoir is not always the proper air pressure that matches the required assist force, but is generally higher than that, and a maximum of 8 kg / cm ² , The pressure is regulated within the range of minimum 6 kg / cm ² .

Therefore, in the conventional booster that is operated by the air pressure introduced from the air reservoir to the cylinder chamber as it is, the assist force fluctuates according to the change in the air pressure in the air reservoir, and the shift operation force is not constant. . Further, if the air pressure is high, the assist force becomes excessively large, and the load on the synchro mechanism of the transmission and the claws of the shift forks becomes excessively large, so that there is a problem that durability of these is deteriorated.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a gear shift booster for a transmission that can always obtain a constant and appropriate assist force.

<Means for Solving the Problem> Therefore, the present invention is a gear shift booster for a transmission, which uses fluid pressure to reduce the shift operation force of the transmission, and is divided by a piston to respond to the shift operation. Each cylinder chamber to which fluid pressure is introduced is provided with one fluid discharge passage connected to one end, and the valve is opened when the fluid pressure introduced from each cylinder chamber via each fluid discharge passage becomes excessive. With one pressure regulating valve to
In the pressure control valve, a valve body that receives fluid pressure from the fluid discharge passages and slides is housed in a case in which the other ends of the fluid discharge passages are connected to wall surfaces facing each other.
There are projections on both sides of the valve body that block the fluid discharge passages when the valve body slides, and elastic forces are exerted on the sliding movements of the valve body in the spaces inside the case on both sides of the valve body. The valve body slides when the fluid pressure in the cylinder chamber that is blocked by the valve body at the neutral position of the valve body and is introduced into the case through the fluid discharge passage becomes excessive pressure. A fluid discharge hole that opens at a position to discharge the fluid pressure to the outside is provided on the valve body sliding wall surface of the case.

<Operation> In the above configuration, the air pressure in the air reservoir is introduced into one cylinder chamber of the booster in accordance with the shift operation of the driver. At this time, air pressure is introduced to one space side of the case of the pressure control valve through the fluid discharge passage connected to the cylinder chamber on the air pressure introduction side, and the valve element is provided with elastic force of the spring provided in the opposite space. And the other fluid discharge passage is closed by the projection. Then, when the introduced air pressure becomes excessive, the valve body moves beyond the position of the fluid discharge hole provided on the wall surface of the case, the fluid discharge hole opens, and the air pressure introduced into the case is discharged to the outside. As a result, the air pressure in the cylinder chamber drops. Then, as the air pressure decreases, the valve body slides toward the original position, the fluid discharge hole is closed, and the discharge of the air pressure is stopped.

In this way, since the air pressure acting on the piston is always a constant pressure, a stable assist force can be obtained. Further, by appropriately setting the valve opening pressure of the pressure regulating valve, it becomes possible to prevent an excessive force from being applied to the synchro mechanism of the transmission or the like without the assist force becoming excessively large.

<Embodiment> An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the configuration of an embodiment of the booster according to the present invention.

In the figure, a hollow actuating rod 21
The closed end side is connected to a control lever (not shown) on the driver's seat via a link, and the other end side is connected to a pipe 24 via a connector 23. At the center of the pipe 24, a compressed air introduction hole 26 is formed which is connected to the compressed air supply pipe 12 connected to the air reservoir 11 via a connector 25 to introduce compressed air into the valve portion.

The valve portion includes a pair of valve lifters 28a and 28b slidably provided in a shifter rod 27 to which the shift lever 22 is coaxially fixed, a pair of valve seats 29a and 29b fixed to the shifter rod 27, and a pipe 24. It is composed of a pair of valve seals 31a, 31b and the like which are slidably fitted and are urged in a direction of separation from each other by a valve spring 30 and abut against the valve seats 29a, 29b, respectively. 32a and 32b are return springs, and 33 is a stopper plate fixed to the pipe 24.

A housing 34 is provided outside the shifter rod 27, and cylinder chambers 36a and 36b partitioned by a piston 35 fixed to the outer periphery of the shifter rod 27 are formed.
The cylinder chambers 36a, 36b have spaces between the valve lifters 28a, 28b and the valve seats 29a, 29b via the communication holes 37a, 37b formed in the valve seats 29a, 29b and the communication holes 38a, 38b formed in the shifter rod 27. Communicating with the department.

Further, in both of the cylinder chambers 36a, 36b, air discharge passages 39a, 39b are provided as fluid discharge passages for discharging the introduced compressed air to the outside as needed. The ends of the air discharge passages 39a, 39b are connected to the cylinder chambers 36a, 3b.
It is connected to a case 51 of a pressure regulating valve 50 that opens when the air pressure introduced into 6b becomes excessive. The pressure control valve 50
The air discharge passages 39, 39b are connected to both sides of the case 51, and the valve body 54 having projections 52 on both sides is provided in the case 51.
Is slidably stored. Both sides of the valve body 54 and the case
Springs 55 and 56 are interposed between the inner wall and the inner wall 51. Further, an air discharge hole 57 as a fluid discharge hole is formed in a substantially central portion of the case 51.

Here, the boosting operation of the booster will be briefly described with reference to FIG.

If the actuating rod 21 moves to the right in the figure by the shift operation of the control lever, the connector 23, the pipe 24, and the stopper plate 33 move in the same direction. Then, the valve lifter 28a moves against the return spring 32a and hits the valve seal, and further overcomes the spring force of the valve spring 30 and the compressed air pressure introduced through the compressed air introduction hole 26 to valve the valve seal 31a. Separated from the sheet 29a. As a result, compressed air is introduced into the cylinder chamber 36a through the communication holes 37a and 38a from the gap between the valve seal 31a and the valve seat 29a, as shown by the arrow in the figure, and exerts pressure on the piston 35 and the shifter rod 27. The shift lever 22 is operated to shift gears.

When the shift operation force is released at the end of the shift, the valve seal 31a will move to the valve seat as the valve lifter 28a retracts.
It is joined to 29a to cut off the supply of compressed air, and valve lifter 28a follows the return of actuating rod 21.
A gap is created between the valve seal 31a and the valve seal 31a. As a result, compressed air is discharged into the atmosphere from the gap between the valve lifter 28a and the pipe 24, and the cylinder chambers 36a on both sides of the piston 35,
The pressure difference of 36b disappears and the boosting action disappears.

Regarding the operation in the opposite direction, the force is transmitted to the valve lifter 28b at the beginning of the operation by the actuating rod 21
It is exactly the same except that it is directly performed on the end face of the above, and the description thereof will be omitted.

Next, the operation of the pressure regulating valve, which is a feature of this embodiment, will be described.

When the driver performs a shift operation, the side corresponding to the shift operation direction of the cylinder chambers 36a, 36b of the booster becomes in communication with the air reservoir 11 along with the shift operation, and the compressed air causes the air supply pipe 12 to flow from the air reservoir 11. Be introduced through. Here, in the following description, the case where compressed air is introduced to the cylinder chamber 36a side will be described.

The air pressure introduced into the cylinder chamber 36a is the air discharge passage 39a.
Is introduced into the case 51 of the pressure regulating valve 50 via. The introduced air pressure causes the valve body 54 to move rightward in the figure against the elastic force of the spring 56, and the projection 52 closes the air discharge passage 39b. At this time, if the air pressure is equal to or higher than a predetermined value, the valve body 54
Moves rightward beyond the position of the air discharge hole 57 in the center of the case 51, and releases the air pressure in the cylinder chamber 36a to the outside. This reduces the air pressure in the cylinder chamber 36a,
As the air pressure decreases, the elastic force of the spring 56 causes the valve body 54 to move leftward in the figure, and when the air pressure falls below a predetermined value, the valve body 54 moves to a position where it blocks the air discharge hole 57 in the center of the case 51. The discharge of the air pressure in the cylinder chamber 36a is stopped. When compressed air is introduced into the cylinder chamber 36b,
The valve body 54 moves in the opposite direction to the above, and the same operation is performed.

Therefore, the air pressure in the cylinder chambers 36a and 36b is always kept constant by the pressure adjusting valve 50. Therefore, the assist force by the booster can be controlled to be constant, the shift operation force can be made constant, and the shift operability is improved.

Then, the assisting force does not become excessively large, and an excessive load is not applied to the synchro mechanism or the like on the transmission side, so that deterioration of these durability can be prevented.

Further, the air pressure in the air reservoir 11 varies in the range of 6 to 8 kg / cm ² , but if the opening pressure of the pressure regulating valve 50 is set to the lower limit value of the air reservoir 11, the cylinder chambers 36a, 36b
The air pressure introduced into the inside is at least equal to or higher than the opening pressure of the pressure regulating valve 50, so that the assist force can be further stabilized, the shift operation force can be reliably kept constant, and the shift operability can be further improved. it can.

Furthermore, only one pressure adjusting valve 50 is required, and the air discharge passage 36a,
Compared with the case where a pressure adjusting valve is provided for each 36b, there is an advantage that the number of parts and cost can be reduced.

A pressure adjusting valve may be provided in the air piping system from the air reservoir to the booster to introduce compressed air whose pressure has been adjusted in advance to the booster. However, in this case, the cylinder chamber of the booster may be used. The inflow speed of the compressed air introduced into the engine is reduced, the assist force of the booster is delayed, and the shift operation time becomes long, which is not desirable.

<Effect of Device> As described above, according to the present invention, a fluid discharge passage is provided in the cylinder chamber of the booster, and a pressure adjusting valve is provided in this passage to make the fluid pressure in the cylinder chamber constant. Therefore, the assisting force of the booster can be made constant at all times, and the shift operating force becomes constant, so that the shift operability is improved.
Further, it is possible to prevent an excessive load from being applied to the synchro mechanism and the like on the transmission side, and it is possible to prevent deterioration of durability of each component of the transmission. Further, only one pressure adjusting valve is required, and the manufacturing cost and the number of parts can be reduced as compared with the case where the pressure adjusting valve is installed for each fluid discharge passage. Furthermore, when the valve body slides, one protrusion is used to close one fluid discharge passage to seal one space in the case. Therefore, in addition to the spring force, the fluid pressure in the sealed space causes a reaction force to the valve body. Is added as. Therefore, a larger reaction force can be obtained as compared with the case where only the spring force is used, and there is an advantage that the pressure regulating valve can be made compact.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a booster according to the present invention,
FIG. 2 is an enlarged view of an essential part for explaining the boosting action of the booster. 11 …… Air reservoir, 12 …… Compressed air supply pipe, 35 …… Piston, 36a, 36b …… Cylinder chamber, 39a, 39b …… Air discharge passage, 50 …… Pressure adjusting valve

Claims (1)

(57) [Scope of utility model registration request] 1. A gear shift booster for a transmission in which a fluid pressure is used to reduce the shift operation force of the transmission, and both cylinder chambers are partitioned by pistons and fluid pressure is introduced in response to the shift operation. And each pressure discharge valve having one end connected to each of the cylinders, and one pressure adjusting valve that opens when the fluid pressure introduced from each cylinder chamber via each fluid discharge passage becomes excessive. In the pressure control valve, a valve body that receives fluid pressure from the fluid discharge passages and slides is housed in a case in which the other ends of the fluid discharge passages are connected to wall surfaces facing each other.
There are projections on both sides of the valve body that block the fluid discharge passages when the valve body slides, and elastic forces are exerted on the sliding movements of the valve body in the spaces inside the case on both sides of the valve body. The valve body slides when the fluid pressure in the cylinder chamber that is blocked by the valve body at the neutral position of the valve body and is introduced into the case through the fluid discharge passage becomes excessive pressure. A gear shift booster for a transmission, comprising a fluid discharge hole that is opened at a position and discharges fluid pressure to the outside on the valve body sliding wall surface of the case.