JPH0563667B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a drive device for switching gears of an automobile transmission having a synchronized mesh mechanism, and is particularly suitable for use in a drive device of a large automobile transmission. Suitable.

[Conventional technology]

2. Description of the Related Art In order to change the gears of a transmission by remote control or automatic control, a power cylinder is known to perform a pull shift. Conventional power cylinders, for example those that utilize air pressure, are controlled by valve operations that supply or discharge constant pressure to the cylinder, and the force acting on the gear shift lever is approximately constant over the period of movement of the piston.

On the other hand, transmissions are equipped with a synchronized mesh mechanism, and when the driver manually operates the gear shift lever, the shift lever is moved with a weak force at the stroke position where the synchronized mesh operates, and the gears are moved. At the stroke position where the gears engage, a strong force is used to move the gear shift lever. If this is operated with a certain amount of force, the synchronized mesh mechanism will not operate smoothly, causing so-called gear noise and resulting in poor operation. This is especially noticeable in large vehicles.

[Problem that the invention seeks to solve]

When designing an automatic transmission for a large vehicle using power shift, the inventor conducted various tests and found that the above-mentioned gear noise could be prevented by weakening the force of the pressure cylinder, but the noise required for shifting It takes a long time and interferes with smooth driving,
On the other hand, it was found that if the force of the pressure cylinder was increased, gear noise would occur, the synchronized mesh mechanism would not operate smoothly, and the gears would wear out quickly.

The present invention is an improvement on this problem, and an object of the present invention is to provide a drive device for a transmission in which the time required for shifting is short and the synchromesh mechanism operates smoothly.

[Means for solving problems]

The present invention provides a drive device for a transmission comprising a pressure cylinder, a piston that moves within the pressure cylinder, and a piston rod connected to the piston, and in which a lever of the transmission is connected to the piston rod. The piston has ventilation holes on both sides of the piston's regular movement range, and each of the ventilation holes on both sides is connected to an electromagnetic three-way valve that switches between introducing compressed air and exhausting the air from the ventilation hole. and a control circuit that controls the energizing current of the electromagnetic three-way valves on both sides in relation to each other, and the control circuit once energizes one of the electromagnetic three-way valves on the opposite side to the side where the piston is located. and introduces compressed air, and after a predetermined time, energizes the other electromagnetic three-way valve to introduce the compressed air, and also controls to release the one electromagnetic three-way valve and discharge the introduced compressed air. It is characterized by

[Effect]

Three-way electromagnetic valves are provided in the vents provided at the left and right ends of the pressure cylinder to supply or discharge compressed air. Compressed air is sent to both sides of the piston of the pressure cylinder from one of these two sets of electromagnetic three-way valves, and discharged from the other to move the piston, but inside the pressure cylinder on the opposite side from where the piston is located. Once compressed air is introduced, the pressure in the two chambers sandwiching the piston can be controlled by controlling the control sequence so that the introduced compressed air is discharged and the compressed air is sent to the other chamber. Since the change in the difference can be controlled and the piston travel time and shift force can be adjusted, it is possible to control the drive of a transmission compatible with synchromesh.

〔Example〕

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a configuration diagram of the main parts of the first embodiment of the present invention, showing a pressure cylinder C, a piston PS moving inside this pressure cylinder C, a piston rod PR connected to this piston PS, and this piston rod.
Lever LV that is connected to PR and drives a transmission (not shown)
It consists of

Here, the feature of the present invention is that inside the pressure cylinder C, there are vent holes P in the chambers A and B on both sides that are divided when the piston PS moves steadily.
Compressed air from the tank R is introduced into the vent holes P1 and P2 through the air pipe A1, and air from the vent holes P1 and P2 is introduced into the air pipe A, respectively.
Electromagnetic three-way valve SL1 that switches the state of exhaust through air throttles T1 and T2 through T2 and A3
and SL2 are connected. moreover,
The electromagnetic coils C1 and C2 of these three-way electromagnetic valves SL1 and SL2 are provided with a control circuit CP that controls the currents applied through paths 1 and 2, respectively, in relation to each other.

In FIG. 1, for illustrative purposes, the chamber A on the left side of the piston PS is depicted as having some space, but in reality, the piston PS is in contact with the left end surface of the inner wall of the pressure cylinder C.

Solenoid three-way valves SL1 and SL2 are paths 1 and 2
When the electromagnetic coils C1 and C2 are energized and energized by the control circuit CP via the control circuit CP, the valves V1 and V2 are pushed down against the springs SP1 and SP2, respectively. Thereby, the air pipe A1 is communicated with the air pipe A2 or A3, respectively, and compressed air is sent into the chamber A or B. When the current flowing through the electromagnetic coils C1 and C2 is cut off and the valves V1 and V2 are demagnetized, the springs SP1 and SP2
, thereby cutting off the communication between the air pipe A1 and the air pipe A2 or A3. As a result, chamber A
The compressed air stored in
Each is released into the atmosphere.

Now move the piston PS from the left side to the right side in Figure 1.
In other words, consider the case of moving from the room A side to the room B side. In this case, curve a in the pressure change curve diagram in FIG.
Activate the solenoid three-way valve SL2 for t _a time as shown in
The pressure in chamber B is increased, and after t _a time, the solenoid three-way valve SL2 is demagnetized, and the solenoid three-way valve SL is
1, the pressure in chamber A increases according to curve c, and the pressure in chamber B decreases according to curve b. The movement of piston PS toward chamber B is due to the difference in pressure acting on both sides of the piston, so in Fig. 2,
Starting from the intersection x of curve b and curve c, time
After T _a , the piston PS completes its movement to the chamber B side.
Since the shapes of curves b and c are constant, the magnitude of this time T _a changes depending on the pressure value at the intersection x. In other words, if the pressure at point x is high, the time T _a
becomes larger.

Furthermore, as shown in Figure 3, the electromagnetic three-way valve SL2
is energized so that the pressure rise in chamber B becomes curve d,
Stop after a short time t _b and immediately turn off the solenoid three-way valve SL1
When the pressure in chamber A is increased as shown by curve f by energizing
The movement is completed after a time T _b . In this case, the pressure at the intersection y is lower than the pressure at the intersection x, since the time t _b is shorter than the time t _a shown in FIG. Therefore, the moving time T _b of the piston PS from chamber A to chamber B is as shown in Fig. 2.
It will be shorter than T _a .

In this way, in FIG. 1, the electromagnetic three-way valves SL1 and SL are controlled by paths 1 and 2 of the control circuit CP.
By changing the sequence of energizing or demagnetizing the piston 2, the movement time and shift force of the piston PS can be adjusted.

〔Effect of the invention〕

According to the present invention, the driving force when changing gears of an automobile transmission can be adjusted as appropriate, so that excessive force is not applied to the synchronized mesh mechanism of the transmission, preventing damage and extending the life of parts. effective.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the main parts of a first embodiment of the present invention. Second
The figure is a pressure change curve diagram when the piston travel time is long. Figure 3 shows the pressure change curve when the piston travel time is short. A, B...chamber, A1, A2, A3... air pipe,
C...pressure cylinder, C1, C2...electromagnetic coil, CP...control circuit, EX1, EX2...exhaust port,
LV...Lever, P1, P2...Vent hole, PR...
Piston rod, PS...piston, R...tank, SL1, SL2...electromagnetic three-way valve, SP1, SP2
... Spring, T1, T2 ... Air throttle, V1, V2
... Valve, 1, 2 ... Pass, a to f ... Curve showing pressure change, t _a , t _b ... Pressure rise time, T _a , T _b ...
Piston travel time.

Claims (1)

[Claims] 1. A transmission drive device comprising a pressure cylinder, a piston that moves within the pressure cylinder, and a piston rod connected to the piston, and in which a transmission lever is connected to the piston rod, The above pressure cylinder has ventilation holes on both sides of the piston's regular movement range, and an electromagnetic three-way switch that switches between introducing compressed air and exhausting air from the ventilation holes on both sides. The valves are connected to each other and include a control circuit that controls the energizing current of the electromagnetic three-way valves on both sides in relation to each other, and the control circuit once controls one electromagnetic three-way valve on the side opposite to the side where the piston is located. energize and introduce compressed air,
A transmission characterized by comprising means for controlling the other electromagnetic three-way valve to be energized to introduce compressed air after a predetermined time, and the one electromagnetic three-way valve to be released to discharge the introduced compressed air. drive unit.