JPH09210197A - Booster for transmission operation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the inferior influence to the operation feeling, and simplify the structure inexpensively. SOLUTION: Communicating grooves 3a, 3b are respectively provided to the inner circumference of a cylinder 3 in the pressure chambers 7a, 7b when a piston 4 is at the neutral position to mutually communicate two pressure chambers 7a, 7b in the state that the piston 4 is reached to the position of either one of communicating grooves 3a, 3b when actuated to synchronize the transmission gear to flow pressurized air through either one of the communicating groove 3a, 3b, from the higher pressure chamber to the lower pressure chamber, in response to the decrease of load immediately after the engagement, to decrease the output power.

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. 4 is a vertical sectional view showing a non-operating state of a conventional power booster for operating a transmission, and FIG. 5 is an enlarged vertical sectional view showing a main part in the operating 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
The piston 4 defines two pressure chambers 7a and 7b in the cylinder 3, and the pair of free pistons 10 and 11 define buffer chambers 12a and 12b on both sides. The buffer chamber 12a,
Retainers 14 and 15 are housed in 12b.

Further, the booster 1 includes a pair of fixed valve seats 22 and 23, valve bodies 24 and 25, valve lifters 26 and 27, which constitute the switching valve 13, and a pair of left and right pressing rings 3.
A pair of free pistons 10 and 11 each having an orifice 20 and 21 are biased by corresponding compression springs 16 and 17.

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 left valve lifter 26 is pushed by the pressing ring 3.
The valve body 24 is pressed by the valve 2 to separate it from the fixed valve seat 22. When the valve body 24 separates from the fixed valve seat 22, the compressed air introduced into the fixed valve seat 22 through the compressed air supply port 29, the air pipe 30 and the through hole 31 thereof supplies and exhausts one of the output rods 5. It is introduced into the pressure chamber 7a on the left side through the hole 8, and this pressure causes the output rod 5 to move rightward via the piston 4 as shown in FIG.

As the output rod 5 moves, the retainer ring 6b of the piston 4 contacts the free piston 11, and the pressure in the buffer chamber 12b rises as the free piston 11 moves, and this pressure passes through the piston 4. It acts as a load on the output rod 5. At this time, a part of the air compressed in the buffer chamber 12b passes through the orifice 21 of the free piston 11 and flows out of the pressure chamber 7b.
Is gradually discharged to the outside through the air supply / exhaust hole 9 and the inner peripheral portion of the valve lifter 27 through the gap between the retainer ring 6b and the retainer ring 6b. Moving. 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) rotates. Due to this rotation, the shift operation shaft also rotates and the shift operation is performed.

After that, when the output rod 5 has completed the shift movement and the hand is released from the change lever, the operation rod 28 and the valve lifter 26 move to the left, and the valve body 2
4 sits down. The compressed air in the pressure chamber 7a is discharged to the outside through the inner peripheral portion of the valve lifter 26. When the operating rod 28 is moved in the direction opposite to the arrow P from this state, the valve lifter 27 is pressed by the pressing ring 33 to separate the valve body 25 from the fixed valve seat 23, and the operation opposite to the above-described operation is performed. It

[0008]

However, in the booster 1 described above, the retracting force is suddenly reduced and the lever is retracted when the shift gears are brought into a synchronized state and engaged by the synchronizing mechanism during the shift operation. The pair of free pistons 1 biased by the respective compression springs 16 and 17 in order to prevent the operation feeling from being deteriorated.
0 and 11 and buffer chambers 12a and 12b are provided, and the buffer chamber 12
Since the retainers 14 and 15 are provided on the a and 12b, respectively, the structure is complicated and expensive.

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 meshing 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 for operating a transmission, which can reliably prevent the operation feeling from being deteriorated due to the pulling feeling of the lever being pulled, and which has a simple structure and is inexpensive.

[0010]

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. A booster for operating a transmission, which relatively displaces a rod in the axial direction 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. In, in each of the two pressure chambers when the piston is in the neutral position, a communication groove is provided on the inner circumference of the cylinder, and the two pressure chambers are connected in a state where the piston reaches the position of the communication groove during operation. Mutual It is characterized in that compressed air is caused to flow through the communication groove from the high pressure side pressure chamber to the low pressure side pressure chamber in accordance with the load reduction immediately after the transmission gears are brought into communication and the transmission gears are synchronized and meshed with each other to reduce the output. .

[0011]

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. And FIG.
4 is a view seen from the opposite direction to FIG. 4, and the same or corresponding portions as those in FIGS. 4 and 5 are denoted by the same reference numerals and duplicate description of those portions will be omitted as much as possible.

In this booster device 1A for operating a transmission, a communication groove 3 is formed on the inner circumference of a cylinder 3 attached to a housing 2.
When the piston 4 defining the two pressure chambers 7a, 7b is provided in the housing 2 in the neutral position, the communication grooves 3a, 3b are respectively provided in the two pressure chambers 7a, 7b. There are each.

Then, as shown in FIG. 3, one of the operation rods 28, for example, is moved in the direction of arrow Q at the time of operation so that the piston 4 reaches the position of the communication groove 3b on the left side. The pressure chamber 7a is communicated with the low pressure side pressure chamber 7b, and the high pressure side pressure chamber 7a is communicated with the low pressure side pressure chamber 7b in accordance with the sudden decrease in load after the gears are meshed in a synchronized state. The feature is that compressed air is made to flow through to enable a rapid decrease in output.

The cylinder 3 is divided into two pressure chambers 7a and 7b by being partitioned by the piston 4, and each of the pressure chambers 7a and 7b at the neutral position of the piston 4 is formed as shown in FIG. The communication grooves 3a and 3b are arranged substantially symmetrically with respect to the piston 4.

The communication grooves 3a, 3b have a uniform mountain-shaped cross section with a width substantially the same as that of the seal groove 4a of the piston 4, and are provided in an annular shape along the inner circumference of the cylinder 3 to change the speed change gear. The position is set according to the position when the load is reduced immediately after meshing in a synchronized state, and as shown in FIG. 3, when the piston 4 arrives and the position matches, the seal member 36 of the piston 4 A communication passage 35 is formed between the outer periphery and a groove surface having a chevron cross section, and compressed air is caused to flow from the high pressure side pressure chamber 7a to the low pressure side pressure chamber 7b through the communication passage 35, thereby providing a booster. This is for reducing the output of 1A.

When the piston 4 slides to the side opposite to the above, the left side pressure chamber 7b becomes the high pressure side, the right side pressure chamber 7a becomes the low pressure side, and through the right side communication groove 3a, in the opposite direction to the above. Compressed air flows.

The piston 4 is provided with an annular seal groove 4a having a rectangular cross section on its outer periphery, and an annular seal member 36 is fitted in the seal groove 4a. Sealing member 36
3 has an annular shape, and as shown in FIG. 3, an inner ring 37 and an outer ring 38 having a substantially circular cross section are integrally connected by a constricted portion 39, and the inner ring 37 and the outer ring 38 are respectively connected to the back ring. Arranged facing each other and annular ridges 37a, 3
8a is provided, and the notch 38b is provided only in the annular protrusion 38a of the outer ring 38.

Then, the piston 4 has a communication groove 3a, 3b of the cylinder 3 between the neutral position and the communication groove 3a, 3b.
The outer periphery of the seal member 36 is located in the cylinder 3
When it is in sliding contact with the inner peripheral surface of, the compressed air in the pressure chamber on the high pressure side passes through the notch 38b and enters the annular space 40 between the annular projections 37a, 38a, and the annular space 40 becomes high pressure. The sealing function of the sealing member 36 is exerted. The position of the piston 4 at the time of completion of synchronization, that is, the synchronization position, is an intermediate position S, between the neutral position and the communication grooves 3a, 3b shown in FIG.
The shift completion position is at intermediate positions C, C between the communication grooves 3a, 3b and both ends of the cylinder 3.

The valve lifters 26 and 27 have slits 26a and 27a for exhaust. Further, one pressing ring 32 is provided integrally with the output rod 5, the other pressing ring 33 is attached to the air pipe 30, and slides on one of the pair of guide cylinders 43 and 44 fitted to the output rod 5. It fits freely.

The operation of the booster according to the above embodiment of the present invention will be described. When the operating rod is moved in the direction of arrow Q in FIG. 1, the valve lifter 26 opens the valve body 24 of the switching valve 13, and accordingly the right pressure chamber 7 is opened.
Compressed air is supplied to a. 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.

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.

The operation of the output rod, the piston and the like associated with the above operation will be described in detail. In the neutral state, that is, in the neutral state, there is no compressed air in both pressure chambers 7a and 7b in the cylinder 3, and as shown in FIGS. 1 and 2,
The communication grooves 3a and 3b are arranged substantially symmetrically with respect to the piston 4 in the neutral state.

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.

Next, when the gear of the transmission is engaged, the striker 34 moves contrary to the above, and the output rod 5 and the piston 4 move in conjunction with this movement. However, FIG.
, The pressure chamber 7a on the high pressure side passes through the communication groove 3b.
Since compressed air flows from the low pressure side into the pressure chamber 7b, the output is sharply reduced and the rapid movement of the piston 4 is suppressed.

The booster 1A according to this embodiment has the advantages that the structure is simple and the assembly is easy, and the seal member when the piston 4 is at a position other than the positions of the communication grooves 3a, 3b. 36 has a good sealing function.
Further, the pair of free pistons 10 and 11 and the buffer chambers 12a and 12b and the buffer chamber 12 in the conventional case shown in FIG.
Retainers 14 and 15 in a and 12b, and compression spring 1
There is an advantage that 6 and 17 are unnecessary.

The present invention is not limited to the above-mentioned embodiments, and various modifications can be made without departing from the spirit of the invention. For example, the communication grooves 3a and 3b
The cross-sectional shape of the seal groove 4a may be changed to a shape other than a mountain shape, and the cross-sectional shape of the seal groove 4a may be changed to a shape other than a square shape.

[0029]

According to the present invention, a communication groove is provided on each of the inner circumferences of the cylinders in the two pressure chambers when the piston is in the neutral position, and when the piston reaches the position of the communication groove during operation, two pressures are applied. By making the chambers communicate with each other and reducing the load immediately after meshing the transmission gears in synchronization, the compressed air flows from the high pressure side pressure chamber to the low pressure side pressure chamber through the communication groove to reduce the output. , During the shift operation, when the shifting gears are brought into a synchronized state by the synchronizing mechanism and meshed, the operation force suddenly becomes light and the operation feeling is surely prevented from being deteriorated due to the pulling feeling of the lever being pulled in. Since it is possible to provide the communication groove in the cylinder, it is possible to provide the booster for operating the transmission, which has a simple structure and is inexpensive. Further, even when the gear is disengaged, the compressed air passes through the communication groove after the booster is operated, so that the reduction of the operating force at the time of gear disengagement is not impaired.

[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 longitudinal sectional view of FIG. 2;

FIG. 4 is a vertical cross-sectional view showing a non-actuated state of a conventional transmission booster.

5 is a longitudinal cross-sectional view showing an enlarged main part of the booster for operating the transmission of FIG. 4 in an operating state.

[Explanation of symbols]

 1A Transmission booster 2 Housing 3 Cylinder 3a, 3b Communication groove 4 Piston 4a Seal groove 5 Output rod 6a, 6b Retainer ring 7a, 7b Pressure chamber 13 Switching valve 22, 23 Fixed valve seat 24, 25 Valve body 26 26 , 27 Valve lifter 32, 33 Pressing ring 28 Operation rod 34 Striker 35 Communication passage 36 Sealing member

Claims (1)

[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 a booster device for operating a transmission, which supplies compressed air to one of the pressure chambers to operate the output rod to rotate the shift operation shaft, the two pressure chambers when the piston is in a neutral position. Immediately after engaging the two pressure chambers with each other in the state where the piston reaches the position of the communication groove at the time of operation, and the transmission gears are synchronized with each other, and the transmission gears are synchronized with each other. A booster for operating a transmission, wherein compressed air is caused to flow from the high-pressure side pressure chamber to the low-pressure side pressure chamber through the communication groove in accordance with the decrease in the load of the transmission device to reduce the output.