JPH09217828A - Boosting device for operating transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent worsening of an operation feeling as a result of a lever being pulled in due to rapid lightening of an operation force when a shift gear is brought into a synchronous state for engagement. SOLUTION: A boosting device for operating a transmission comprises the valve elements 24 and 25 of a switching valve 13 to selectively feed compressed air to pressure chambers 7a and 7b; and valve lifters 26 and 27, which are opened through press of the valve elements, and press rings 32 and 33. Press rings 32 and 33 are loosely fitted in the central holes 18b and 19b of guide cylinders 18 and 19 to guide valve lifters 26 and 27 fitted in the inner periphery of an output rod 5 and throttle parts 20 and 21 are formed in the middle of a discharge flow passage. Simultaneously with the decrease of a load right after, during operation, a shift gear is brought into a synchronous state for engagement, an amount of air discharged through the throttle part communicated with a pressure chamber on the low pressure side is decreased and a throttle part communicated with a pressure chamber on the high pressure side is opened and an output is decreased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a booster for operating a transmission, and more particularly to a shift operation of the transmission (when the gear is turned on).
The present invention relates to a booster for operating a transmission capable of preventing sudden acceleration of the output rod by rapidly reducing the shift operating force in accordance with the sudden decrease in the synchronous load of the synchronous mechanism.

[0002]

2. Description of the Related Art Transmission operations generally require greater force for shift operations than select operations. For this reason,
Particularly in buses and trucks having large transmissions, a booster is incorporated in the transmission operating device so that a smooth shift operation can be performed with a light force.

FIG. 7 is a longitudinal sectional view showing a non-actuated state of a conventional power booster for operating a transmission, and FIG. 8 is an enlarged longitudinal sectional view showing an essential part in the actuated state. This booster 1
Is mounted on the outer circumference of the output rod 5 by holding the piston 4 sliding in the cylinder 3 mounted on the housing 2
This piston 4 is positioned and attached by a and 6b.
In the cylinder 3, two pressure chambers 7a and 7b are defined.

Further, in the booster 1, a pair of guide cylinders 18 and 19 are fitted on the inner circumference of the output rod 5, and the switching valve 13 is provided.
Of each pair of fixed valve seats 22, 23 and valve bodies 24, 2
5 and valve lifters 26 and 27 slidably fitted to the inner circumferences of the corresponding guide cylinders 18 and 19. A pressing ring 32 for pressing the right valve lifter 26 is formed integrally with the operating rod 28, and a pressing ring 33 for pressing the left valve lifter 27 is attached to the air pipe 30.

In such a booster 1, when the operating rod 28 is moved in the direction of arrow P by the operation of a change lever (not shown), the air pipe 30 is pulled and the left valve lifter 27 is pressed by the pressing ring 33 to cause the valve to move. The body 25 is separated from the fixed valve seat 23. The valve body 25 is the fixed valve seat 23.
When separated from, the compressed air constantly supplied to the compressed air supply port 29 enters the inside of the fixed valve seat 23 through the air pipe 30 and the through hole 31. The compressed air that has entered here is introduced into the left pressure chamber 7b through one of the air supply / exhaust holes 9 of the output rod 5, and this pressure causes the output rod 5 to
Moves to the right via the piston 4.

Simultaneously with the movement of the piston 4 to the right, the air in the pressure chamber 7a on the right side is supplied to the air supply / exhaust hole 8 of the output rod 5.
And an air supply / exhaust hole 11a of the valve seat cylinder 11 fitted inside thereof,
The outer peripheral space of the valve lifter 26, the clearance between the outer circumference of the valve lifter 26 and the inner circumference of the fixed valve seat 22, the clearance between the inner circumference of the valve lifter 26 and the outer circumference of the air pipe 30, the valve lifter 26
It is discharged to the outside through the slit 26a and the guide tube 18 in sequence.

When the output rod 5 moves to the right, the striker 34 is pushed to the right and moves, and the input lever (not shown) is rotated about the shift operation shaft by the boosted operation force. Along with this, the shift operation shaft rotates about the axis thereof together with the input lever from the neutral position by a predetermined angle, whereby a predetermined shift operation (gear shift) is performed.

When the output rod 5 completes the shift movement, when the hand is released from the change lever, the operation rod 28 and the valve lifter 27 move leftward, and the valve body 25
Sits down. Further, the air in the pressure chamber 7b is discharged to the outside through the inner peripheral portion of the valve lifter 27.

When the operating rod 28 is moved in the direction opposite to the arrow P from this state, the valve lifter 26 is pressed by the pressing ring 32 to separate the valve body 24 from the fixed valve seat 22, and the operation opposite to the above operation is performed. Done. At this time, the air in the left pressure chamber 7b is fixed to the air supply / exhaust hole 9 of the output rod 5 and the air supply / exhaust hole 12a of the valve seat cylinder 12 fitted inside thereof, the outer peripheral space of the valve lifter 27, and the outer circumference of the valve lifter 27. The clearance between the inner circumference of the valve seat 23, the clearance between the inner circumference of the valve lifter 27 and the outer circumference of the air pipe 30, the slit 27a of the valve lifter 27, and the inside of the guide cylinder 19 are sequentially passed through the discharge hole 41 and the discharge hole 42 to the outside. Is discharged.

[0010]

However, in the above-mentioned booster, when the shift gear is engaged and the gears are brought into synchronization with each other during the shift operation, the operating force suddenly becomes light and the lever is pulled in. The operation feeling is bad. Further, there is a drawback that the impact force acts on the dog teeth of the speed change gear and the durability of the dog teeth and the like is impaired.

The present invention has been made in view of the above-mentioned conventional drawbacks, and an object thereof is to suddenly reduce an operating force when engaging a shift gear in a synchronized state by a synchronizing mechanism during a shift operation. It is an object of the present invention to provide a booster device for operating a transmission, which can surely prevent the operation feeling from being deteriorated due to a feeling of pulling in the lever.

[0012]

In order to achieve the above object, the present invention provides a hollow output rod having a piston which defines the inside of a cylinder into two pressure chambers and which is linked to an input lever of a shift operating shaft. And an operation rod slidably fitted to the inner circumference of the output rod for operating a switching valve that selectively supplies compressed air to the pressure chamber, and the operation rod is operated with respect to the output rod. The rod is relatively displaced in the axial direction to operate the switching valve, compressed air is supplied to one of the pressure chambers, air is discharged from the other pressure chamber through a discharge flow passage, and the output rod is operated to shift the shift valve. In a booster device for operating a transmission that rotates an operation shaft, a throttle portion is provided in the middle of the discharge flow path, and the low pressure side of the low pressure side is adjusted in accordance with the load reduction immediately after meshing with the transmission gear in a synchronous state during operation. Connect to pressure chamber With reducing the amount of air discharged through the narrowed portion which, by opening the throttle portion communicating with the pressure chamber of the high-pressure side, characterized in that to reduce the output.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION A booster device for operating a transmission according to an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a vertical cross-sectional view of a booster for operating a transmission according to an embodiment of the present invention in a non-operating state, and FIG. 2 is a vertical cross-sectional view showing an enlarged main part of FIG. The same or corresponding portions as those in FIG. 8 are designated by the same reference numerals, and duplicate description of those portions will be omitted as much as possible.

This transmission operating booster 1A includes a cylinder 3 mounted on a housing 2 and a cylindrical output rod 5 having a piston 4 defining two pressure chambers 7a and 7b in the housing 2. Guide cylinders 18 and 19 fitted in the output rod 5, valve lifters 26 and 27 for pressing and opening the pair of valve bodies 24 and 25 of the switching valve 13, and both pressing rings 32 and 33, The guide tubes 18, 19
The pressing portions 32 and 33 are loosely fitted to the inner circumference of the so as to form the throttle portions 20 and 21.

In the booster 1A, when the pressure chamber 7b on the left side of the drawing is set to the low pressure side in accordance with the load reduction immediately after meshing the transmission gears in a synchronized state during operation, this pressure chamber 7b The amount of air discharged through the throttle portion 21 in the middle of the exhaust flow path from is reduced, and the throttle portion 20 communicating with the pressure chamber 7a on the high pressure side is opened to reduce the output, and immediately after synchronization. The output at the time of gear shift is designed to be sharply reduced.

As shown in FIG. 2, both guide cylinders 18 and 19 integrally have inwardly facing flanges 18a and 19a, which are fitted at predetermined positions on the inner circumference of the output rod 5 to form the flange 1
Air pipes 30 are provided in the center holes 18b and 19b of 8a and 19a.
And the pressing rings 32 and 33 corresponding to the central holes 18a and 19a are loosely fitted in and removed from each other.

One throttle portion 20 is constructed by loosely fitting a pressing ring 32, which is integrally provided on the operating rod 28, into and out of the corresponding central hole 18b of the guide cylinder 18. The other throttle portion 21 is configured by loosely fitting a pressing ring 33 attached to the air pipe 30 into and out of the center hole 19b of the guide cylinder 19.

Both of the throttle portions 20 and 21 are in the middle of the respective exhaust flow passages, and are portions of the pressing rings 32 and 33 on the side opposite to the center holes 18b and 19b, and the corresponding center holes 18b and 19b. Taper part 32 with the side close to
a and 33a are provided. The pressing ring 33 will be described in detail. As shown in FIG.
When the axial dimension L is 0.5 to 2.0 mm, the taper angle θ is 15 to 30 degrees. The same applies to the tapered portion 32a of the pressing ring 32.

The state of the throttle portion 21 is such that
As shown in FIG. 3A, the end surface 33b of the pressing ring 33 is aligned with the inner end surface 19c of the flange 19a, or, as shown in FIG. 3B, the tapered portion 33a of the pressing ring 33.
The whole may just be in the center hole 19b of the flange 19a, and at the time of operation, the pressing ring 33 enters the center hole 19b as shown by the chain double-dashed line.

The operating rod 28 integrally has a pressing ring 32 and a neck 39, and the pressing ring 32 is loosely fitted into the center hole 18b of the flange 18a from the inside of the guide cylinder 18 and is also flanged. The closed end portion 30a of the air pipe 30 is connected to the neck portion 39 which is inserted through the center hole 18b of the air pipe 18a.

The operation of the booster according to the above embodiment of the present invention will be described. In the neutral state, that is, in the neutral state, as shown in FIGS. 1 and 2, both valve bodies 24 and 25 of the switching valve 13 are closed, and both pressure chambers 7 in the cylinder 3 are closed.
There is no compressed air in a and 7b.

When the operating rod 28 is moved in the direction of arrow Q in FIG. 1 from this neutral state, the valve lifter 26 opens the valve body 24 of the switching valve 13, and accordingly compressed air is supplied to the right pressure chamber 7a. It This compressed air pumps the piston 4 to the left. Therefore, the output rod 5 moves leftward as shown in FIG.

Until the synchronized state is reached, the right diaphragm unit 20
Is opened, the valve element 24 is separated from the fixed valve seat 22, and air is supplied to the right pressure chamber 7a. The other throttle portion 21 is throttled to suppress the exhaust from the pressure chamber 7b on the left side and to prevent sudden acceleration immediately after the synchronization.

When the output rod 5 moves to the left, the striker 34 is pushed to the left and moves, and the input lever (not shown) rotates. This rotation also rotates the shift operation shaft to perform the shift operation. Done. During this shift operation, as shown in FIG. 5, the right valve body 24 is closed and the right valve lifter 26 is separated from the valve body 24 (see FIG. 6).
), The narrowed portion 20 on the right side is open. This allows
The compressed air in the pressure chamber 7a on the high pressure side is quickly discharged through the throttle portion 20 on the right side, and the output of the booster 1A sharply decreases.

That is, when the gear of the transmission is engaged, the striker 34 moves in the direction of arrow Q, and in conjunction with this movement,
The output rod 5 and the piston 4 move. However, as shown in FIG. 5, the discharge flow rate from the low pressure side pressure chamber 7b is reduced while the flow passage area of the low pressure side throttle portion 21 is narrowed, and the high pressure side throttle portion 20 is opened to open the high pressure side pressure. Since the discharge flow rate from the chamber 7a is increased and the output is sharply reduced, the rapid movement of the piston 4 is suppressed. From the state of being in the synchronized state until the shift operation is completed, the right valve element 24 abuts on the fixed valve seat 22 and closes, and the left valve element 25 opens apart from the fixed valve seat 23.

When the shift operating rod 28 moves rightward in the direction opposite to the arrow Q in FIG. 1 and is displaced relative to the output rod 5, the valve lifter 27 opens the valve body 25, and accordingly the switching valve. 13 is activated and compressed air is supplied to the left pressure chamber 7b. This compressed air pumps the piston 4 to the right. Therefore, the output rod 5 moves to the right.

When the output rod 5 moves to the right, the striker 34 is pushed to the right and moves, and the input lever is rotated about the shift operation shaft by the operating force boosted in the opposite direction to the above. Move. Along with this, the shift operation shaft rotates about the axis thereof together with the input lever from the neutral position by a predetermined angle, whereby a predetermined shift operation (gear shift) is performed.

According to the booster 1A of this embodiment, the guide tubes 18 and 19 are provided with inward flanges 18a and 19a.
Since it is only necessary to provide the output rod 5, since the structure is simple and the cost is low, the shift operation force is sharply reduced in accordance with the rapid reduction of the synchronous load on the synchronization mechanism during the shift operation of the transmission (when the gear is turned on). It is possible to prevent sudden acceleration.

The present invention is not limited to the above embodiment, and various modifications can be made without adding new matter.

[0030]

According to the present invention, a throttle portion is provided in the middle of the discharge flow passage, and the throttle portion communicates with the pressure chamber on the low pressure side in accordance with the load reduction immediately after meshing the transmission gears in a synchronized state during operation. The amount of air discharged through the valve is reduced, and the output is reduced by opening the throttle that communicates with the pressure chamber on the high pressure side. When adjusting, the operating force suddenly becomes lighter and the feeling of pulling in the lever is eliminated, and it surely prevents the operation feeling from deteriorating.
It is possible to prevent the impact force from acting on the dog teeth and the like. By providing a pressing ring and a valve lifter for pressing and opening the valve body of the switching valve, and a guide cylinder that guides the valve lifter, and by forming a throttle portion by loosely fitting the pressing ring to the guide cylinder, The booster for operating a transmission, which has a simple structure and is inexpensive, can be provided.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a non-operating state of a transmission operating booster according to an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view showing an enlarged main part of FIG.

FIG. 3 is a partially enlarged view of FIG. 2;

FIG. 4 is a vertical cross-sectional view for explaining the operation of the transmission operating booster according to the embodiment of the present invention.

FIG. 5 is a vertical cross-sectional view for explaining the operation of the transmission operating booster according to the embodiment of the present invention.

FIG. 6 is a partially enlarged view of FIG. 5;

FIG. 7 is a vertical cross-sectional view showing a non-actuated state of a conventional booster for operating a transmission.

8 is a vertical cross-sectional view showing an enlarged main part of FIG.

[Explanation of symbols]

 1A Transmission booster 2 Housing 3 Cylinder 4 Piston 5 Output rod 6a, 6b Retainer ring 7a, 7b Pressure chamber 13 Switching valve 18, 19 Guide tube 18a, 19a Inward flange 18b, 19b Center hole 20, 21 Throttle Part 22, 23 Fixed valve seat 24, 25 Valve body 26, 27 Valve lifter 32, 33 Pressing ring 28 Operating rod 30 Air pipe 34 Striker

Claims (2)

[Claims] 1. A hollow output rod which has a piston defining a pressure chamber in the cylinder and is linked to an input lever of a shift operating shaft, and a switching valve which selectively supplies compressed air to the pressure chamber. And an operating rod slidably fitted to the inner circumference of the output rod for operating the operating rod, wherein the operating rod is axially displaced relative to the output rod to operate the switching valve, In the booster for operating a transmission, which supplies compressed air to one of the pressure chambers, discharges air from the other pressure chamber through an exhaust flow path, operates the output rod, and rotates the shift operation shaft, A throttle part is provided in the middle of the discharge flow path, and the air discharged through the throttle part communicating with the pressure chamber on the low pressure side is adjusted in accordance with the load reduction immediately after meshing the transmission gears in a synchronous state during operation. Reduce the amount At the same time, the booster for operating the transmission is characterized in that the throttle section communicating with the pressure chamber on the high pressure side is opened to reduce the output. 2. The booster for operating a transmission according to claim 1, further comprising a pressing ring and a valve lifter for pressing and opening the valve body of the switching valve, and a guide cylinder for guiding the valve lifter. A booster device for operating a transmission, wherein the pressing ring is loosely fitted to the guide cylinder to form the throttle portion.