JPH09222165A - Assistor for transmission operation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the deterioration of an operational feeling caused by the pulling-in of a lever due to the sudden reduction of an operating force when speed changing gears are synchronized to be engaged with each other. SOLUTION: A pair of projections 35 are provided in a striker 34 attached to an exit rod 5 at a prescribed interval in a moving direction, a movement suppressing member 41 engaged with the pair of projections 35 for suppressing the movement of the striker 34 by pressing the projections 35 during the movement of the projections 35 is provided in a housing, the movement suppressing member 41 is brought into contact with specified one of the pair of projections 35 so as to press the projections by the pressing force of a compressing spring 50 corresponding to the reduction of a load immediately after the engagement between the speed changing gears in synchronization with each other, the movement of the exit rod 5 is suppressed via the striker 34, an output is reduced and sudden acceleration after synchronization is reduced.

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 booster for operating a transmission. The booster 1 includes a piston 4 that slides in a cylinder 3 attached to a housing 2.
Is positioned and attached to the outer circumference of the output rod 5 by retainer rings 6a and 6b, and two pressure chambers 7a and 7b are defined in the cylinder 3 by the piston 4.

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 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 the air supply / exhaust hole 12a of the valve seat cylinder 12 and one of the air supply / exhaust hole 9 of the output rod 5, and this pressure causes the output rod 5 to pass through the piston 4. Move to the right.

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 operating shaft (not shown) by the boosted operating 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 has a piston defining a pressure chamber inside a cylinder attached to a housing and is linked to an input lever of a shift operating shaft. An output rod, a striker attached to the output rod, and an operating 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 operating the switching valve by axially displacing the operation rod with respect to the output rod, supplying compressed air to one of the pressure chambers to operate the output rod, and through the striker. In the booster for operating a transmission for rotating the shift operation shaft, a pair of projections are provided on the striker at predetermined intervals in the moving direction, and the housing is engaged with the pair of projections and the projections are provided. Is provided with a movement suppressing member that presses the protrusion during movement of the striker to suppress the movement of the striker, and the movement suppressing member contacts the protrusion according to the decrease in load immediately after meshing with the transmission gears in a synchronized state during operation. The output rod is restrained from moving through the striker and the output is reduced.

[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 showing a main part of a transmission operating booster according to a first embodiment of the present invention in a non-operating state, and FIG. 2 shows the entire transmission operating booster of FIG. It is the longitudinal cross-sectional view shown, and the same code | symbol is attached to the same or corresponding part as FIG. 7, and the overlapping description of those parts is abbreviate | 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. The output rod 5 is provided with guide cylinders 18 and 19, 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. There is. Output rod 5
The striker 34 that engages with the striker 34 is provided with a pair of protrusions 35 and 36, and the housing 2 engages the pair of protrusions 35 and 36 and presses the protrusions when the striker 34 moves.
Is provided with a movement suppressing member 41 that suppresses the movement.

In the booster 1A, the movement restraining member 41 is provided with one of the pair of protrusions 35 and 36 in accordance with a reduction in the load immediately after the gears are brought into a synchronous state and meshed during operation. The output rod 5 is restrained from moving through the striker 34 and the output is reduced.

The striker 34 is fitted and attached to the outer periphery of the output rod 5 and is connected to a shift lever (not shown). The striker 34 moves together with the output rod 5 and is spaced apart in the moving direction by a pair of protrusions 35 and 36. As shown in FIG. 3, a parallel portion 34a between the projections 35 and 36 and parallel portions 34b and 34b at both ends are provided, and the parallel portion 34a and the parallel portion 34 are provided.
b and 34b are flush with each other. The pair of protrusions 35 and 36 are
The movement restraining member 4 has a mountain-shaped contour and is symmetrically arranged.
1, the skirt surface Sk, the intermediate inclined surface Mi and the apex P
e.

The movement restraining member 41 has a hemispherical pressing portion 42.
And a small flange 43 integrally, and the compression spring 5 arranged inside the holding member 46 is retained by the inner end surface of the inward flange 47 of the cylindrical holding member 46 screwed to the housing 2.
The pressing portion 42 is biased in the protruding direction by 0, and the pressing portion 42 is held by the holding member 46 in a retractable state.

The holding member 46 integrally has an outward flange 48, and has a male screw 46a on one end side and a screw hole 46 on the other end side.
b, the male screw 46a is screwed into the housing 2 for attachment, and the spring receiving bolt 51 is screwed into the screw hole 46b.

The compression spring 50 is disposed inside the holding member 46 and between the end face of the spring receiving bolt 51 and the small flange 43, and biases the movement restraining member 41 in the direction in which the pressing portion 42 projects. ing.

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. 2 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 to the left.

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, the movement suppressing member 41 hits the right projection 35 by the movement of the striker 34 in the left direction, and the striker 34 moves.
Control the rapid movement of. As a result, the movement of the output rod 5 is also suppressed, the output of the booster 1A is reduced, and the sudden acceleration after the synchronization is alleviated.

FIG. 3 is an operation explanatory view showing a change in the relative positional relationship between the striker and the pressing portion of the movement restraining member. In this figure, in order to avoid complication of the drawing, the movement restraining member 41 is moved without moving the striker 34 to show the change in the relative positional relationship between the two. In the movement of the striker 34 from the position of the striker 34 where the point P ₀ faces the pressing portion 42 in the neutral state to the position where the point P ₁ faces the pressing portion 42 at the start of the synchronous operation, the parallel portion 34 a moves to the pressing portion 42. Immediately after the synchronization is completed, the predetermined portion P ₂ of the intermediate inclined surface Mi comes into contact with the pressing portion 42.

At the start of gear input of the transmission, the striker 34 moves in the direction of arrow Q, and the output rod 5 and the piston 4 move in conjunction with this movement. However, when the gear is turned on, the pressing portion 42 presses the projection 35 by the urging force of the compression spring 50 and suppresses the movement of the striker 34 between the predetermined position P ₂ of the intermediate inclined surface and the vicinity of the apex Pe.
When the shift operation is completed, the boundary portion P ₃ between the skirt surface Sk on the one end side of the striker 34 and the parallel portion 34b faces the pressing portion 42.

When the shift operating rod 28 moves to the right 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 rotates about the shift operation shaft by the operation 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.

Next, when compressed air enters the pressure chamber 7a on the right side, the piston 4 slides to the left and simultaneously the output rod 5
Moves to the left, and the pressing force is transmitted from the output rod 5 to the striker 34. The action of the movement restraining member 41 on the striker 34 is different from the above-described case shown in FIG. 3 in that the movement direction of the striker 34 is reversed and the left protrusion 36 is pushed by the pressing portion 42 of the movement restraining member 41. It is the same except that it does.

FIG. 4 is a vertical sectional view showing a main part of a booster according to a second embodiment of the present invention. In this booster, the movement suppressing member 41 has a spherical shape, and the holding member 4
6 integrally has a bottom 49. Since the other points are the same as those of the first embodiment, the same parts are designated by the same reference numerals and the duplicate description thereof will be omitted. According to this booster, there is an advantage that the structure is simple and the cost can be reduced.

The present invention is not limited to the above embodiment, and various modifications can be made without adding new matter. For example, the striker 34 is
As shown in FIG. 5, parallel portions 34b, 34b may be provided at both ends flush with the apex Pe of the pair of protrusions, and as shown in FIG.
It is not necessary to be flush with the parallel portion 34a between the portions 5 and 36.

[0030]

According to the present invention, a pair of projections are provided at a predetermined interval in the moving direction of the striker, and the pair of projections are engaged with each other to push the projections when the projections are moved to suppress the movement of the striker. A restraint member is provided on the housing, and the movement restraint member abuts the protrusions to suppress the movement of the output rod through the striker in response to the load reduction immediately after meshing the transmission gears in a synchronized state during operation. When the gears are shifted 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 back, eliminating the feeling of pulling in and making the operating feel worse. This has the effect of preventing and reliably avoiding the impact force acting on the dog teeth and the like.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a main part of a booster device for operating a transmission according to a first embodiment of the present invention in a non-operating state.

FIG. 2 is a vertical cross-sectional view showing the entire power booster for operating the transmission of FIG.

FIG. 3 is an operation explanatory view showing a change in relative positional relationship between a striker and a pressing portion of a movement suppressing member.

FIG. 4 is a vertical cross-sectional view showing a main part of a transmission operating booster according to a second embodiment of the present invention.

FIG. 5 is a partial external view showing a modified example of the striker according to the embodiment of the present invention.

FIG. 6 is a partial external view showing another modification of the striker according to the embodiment of the present invention.

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

[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 28 Operation rod 30 Air pipe 34 Striker 35, 36 Protrusion 41 Movement restraining member 42 Pressing portion 46 Holding Member 50 compression spring

Claims (1)

[Claims] 1. An output rod that has a piston that defines the inside of a cylinder attached to a housing into two pressure chambers and is linked to an input lever of a shift operation shaft, a striker attached to the output rod, and the pressure chamber. An operating rod slidably fitted to the inner periphery of the output rod for operating a switching valve for selectively supplying compressed air to the output rod, and the operating rod is axially arranged with respect to the output rod. A booster device for operating a transmission that relatively displaces to operate the switching valve, supplies compressed air to one of the pressure chambers to operate the output rod, and rotates the shift operation shaft via the striker. In the above, the striker is provided with a pair of protrusions at predetermined intervals in the movement direction, and the housing is engaged with the pair of protrusions and presses the protrusions when the protrusions move to suppress the movement of the striker. A movement restraining member is provided to suppress the movement of the output rod through the striker when the movement restraining member comes into contact with the protrusion in accordance with the reduction in load immediately after meshing the transmission gears in a synchronized state during operation. , A booster for operating a transmission characterized by reducing output.