JP2608749B2 - Transmission operating device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission operating device for automatically operating a shift lever via a power piston by supplying and discharging compressed air. The present invention relates to a transmission operating device including a mechanism that is applied with braking and absorbs volume expansion due to a rise in temperature of damper oil (braking oil).

b. Conventional technology Shift operation requires significantly greater force in shift operation than in select operation. For this reason, especially on buses and trucks having a large transmission, a transmission operation device that automatically operates the shift lever by supplying and discharging compressed air is mounted, so that the driver can perform a smooth shift operation with a light force. It has become.

Incidentally, a synchronous gear is usually used for the gear of the transmission, but the load of the shift operation becomes maximum immediately before the synchronization is completed, and the load suddenly decreases after the synchronization is completed. On the other hand, the transmission operating device is configured to transmit the force of a power piston operated by compressed air to a shift lever. Therefore, the power piston suddenly accelerates immediately after the gear synchronization is completed, and as a result, the dog teeth of the transmission gear and the gear shift fork are impacted and mechanically damaged, resulting in a significant decrease in the durability of the device. There was a risk of

For this reason, as a transmission operating device in which the power piston does not rapidly accelerate even after the gears of the transmission complete synchronization, an oil cylinder is fixedly installed inside the piston rod of the power piston. The present applicant has already proposed a device in which a damper piston having an orifice is slidably fitted inside a cylinder, and the damper piston is connected to a fixed side of the device via a fixed rod. (Japanese Patent Application No. 62-148853) c. Problems to be Solved by the Invention However, in the shift operation of the transmission operating device, when the piston rod strokes, the oil in the oil cylinder causes the orifice of the damper piston to move. In this case, the passage resistance acts on the piston rod in a direction opposite to the stroke direction. Therefore, even when the power piston or the piston rod tries to accelerate rapidly from the start of the shift operation to the synchronization of the transmission gears and the completion of the shift operation, the damping action of the oil cylinder attenuates the acceleration of the piston rod, and therefore,
There is a problem that it takes a long time to complete the shift operation.

In addition, the oil in the oil cylinder passes through the orifice of the damper piston or is compressed to generate heat, and the temperature of the oil rises due to conduction heat directly attached to the transmission and environmental conditions such as region and season. . For this reason, there is also a problem that the internal pressure of the oil cylinder increases due to the volume expansion of the damper oil, which causes breakage and deterioration of seals.

The present invention has been made in view of the above points, and an object thereof is to solve the above-mentioned problems, and during a shift operation, operate quickly from the start of operation at a neutral position to immediately before synchronization of gears of a transmission, and synchronization and synchronization. It is an object of the present invention to provide a transmission operating device capable of smoothly performing gear shifting without sudden acceleration of a power piston after completion and preventing damage due to volume expansion due to heat generation of damper oil.

d. Means for Solving the Problems In the configuration of the present invention for achieving the above-mentioned object, a power piston disposed in a power cylinder is connected to a shift lever of a transmission through a hollow piston rod, In a transmission operating device in which compressed air is selectively supplied to and discharged from a pair of pressure chambers formed on both sides of the power piston to operate the shift lever, an oil cylinder is fixed inside the piston rod. Of the power piston, a cylinder enlarged portion is formed in a portion corresponding to the neutral position of the power piston, and the damper piston is slidably and gently fitted to the inside of the oil cylinder. Inside the fixed rod, a volume expansion absorbing means for the damper oil due to heat is provided, and the volume expansion absorbing means communicates with the oil cylinder. The volume expansion is absorbed by a change in the volume of the hollow portion, and the damper piston is connected to a fixed side of the transmission operating device via the fixed rod.

e. Action The transmission operating device constructed as described above has two different damping actions. That is, in the shift operation, particularly in the operation in the vicinity of the neutral position, when the piston rod operates, the damper piston passes through the enlarged cylinder portion formed in the substantially central portion of the oil cylinder. Here, since the gap between the cylinder enlarged portion and the outer diameter portion of the damper piston is wide,
The damper piston can move quickly. Therefore, the piston rod moves quickly.

Next, just before the transmission gears are synchronized, the damper piston reaches the position of the normal cylinder small diameter part of the oil cylinder, and thereafter the gap is narrow, so that when the oil passes through this narrow gap, The passage resistance damps the piston rod in a direction opposite to its stroke direction. For this reason, even if the power piston or the piston rod attempts to accelerate rapidly during and after the synchronization of the transmission gears, the acceleration of the piston rod is attenuated by the damping action, so that the gear can be shifted smoothly and the transmission can be smoothly shifted. It is possible to prevent an impact from being applied to the gear.

In addition, means for automatically absorbing and adjusting the oil volume expansion due to temperature rise such as heat generation of the damper oil is provided inside the fixed rod of the damper piston to prevent the pressure in the oil cylinder from rising abnormally.

e. Embodiment Hereinafter, a preferred embodiment of the present invention will be illustratively described in detail with reference to the drawings.

FIG. 1 shows a longitudinal section of an embodiment of a transmission operating device according to the present invention. As shown in FIG. 1, this device is mainly constituted by a power cylinder 1, a stroke sensor 2, and an oil damper 3. There is. The power cylinder 1 includes a power piston 5 provided in a cylinder 4 and a pair of auxiliary pistons 6 and 7 provided on both sides of the power piston 5. The position of the power piston 5 shown in the figure is the neutral position.

The power piston 5 is fixed to the piston rod 8, but the pair of auxiliary pistons 6 and 7 are slidably fitted between the inner peripheral surface of the cylinder 4 and the outer peripheral surface of the power piston 5. When compressed air is supplied to and exhausted from the pair of pressure chambers 9 and 10 formed on both sides of the power piston 5, the pressure causes the power piston 5 to stroke in the direction of arrow a or the direction of arrow b. There is. In this case,
The pair of auxiliary pistons 6 and 7 assist the output of the power piston 5 when the gear is disengaged, and the center stopper 11
At the same time, it serves to position the power piston 5 at the neutral position. In FIG. 1, reference numerals 12 and 13 denote solenoid valves, respectively. When the solenoid valves 12 and 13 are turned on and off, the compressed air in the air tank 14 is supplied to and discharged from the pair of pressure chambers 9 and 10. I have.

The stroke sensor 2 includes an extension rod 17 attached to one end of the piston rod 8, a sleeve 19 with a permanent magnet 18 fitted on the outer periphery of the extension rod 17, and a magnetoelectric conversion element.
The sensor unit 21 includes a sensor unit 20 for detecting the position of the permanent magnet 18 and transmitting a detection signal to a controller (not shown).

The oil damper 3 is fixedly fitted to the inside of the other end of the piston rod 8 and has an oil cylinder 24 having a cylinder expansion portion 24a formed in the center portion of the inside thereof, and a small gap inside the oil cylinder 24. The damper piston 25 is loosely fitted through the damper piston 25, and its center is fixed to or integrally formed with the damper piston 25, and both ends are slidably fitted to the end walls 24b, 24c of the oil cylinder 24. The fixed rod 26 is inserted. Here, the length in the stroke direction of the cylinder enlarged portion 24a formed in the central portion inside the oil cylinder 24 is determined in consideration of the stroke from the neutral position of the transmission to immediately before the transmission gear is synchronized. Note that one end 26a of the fixed rod 26 is fixed to a rod cover 27.

FIG. 2 shows an enlarged vertical cross-section of the oil damper 3 and, at the same time, shows a mechanism for absorbing volume expansion of oil due to heat generation of the damper oil. In the figure, a cylinder 28 is formed on the other end 26b side of the fixed rod 26. One end of the cylinder 28 is communicated with the inside of the oil cylinder 24 through a communication hole 29, and the other end is connected to the atmosphere. A spring stopper 31 having a through hole 30 communicating with the spring is screwed. Inside the cylinder 28, a piston 34 slidably fitted is disposed via an oil seal 32 and a duster seal 33, and the piston 34 is a spring.
By 35, it is always urged from the atmosphere side to the damper oil side. The spring 35 is for constantly applying a preload to the oil in the oil damper 3.

Damper oil is enclosed in the oil cylinder 24, and a taper hole 24e is formed substantially in the center of the cylinder side wall of the oil cylinder 24. After the oil is enclosed, it is sealed with a steel ball 24f. There is. When oil is sealed in the oil cylinder 24, first, as shown in FIG. 3, the taper hole 24e is sealed with a rubber plug 36, and then a pipe line 37a is connected to the other end 26b side of the fixed rod 26. Open cock 37c with cock 37b closed. When the cock 37c is opened, the air in the oil cylinder 24 is extracted by the vacuum pump 37d, and then the cock 37c is closed and the cock 37b is opened. When the cock 37b is opened, the oil in the oil tank 38 is replaced with the oil cylinder 2
Since it is sucked into 4, the pipe 37a is removed when the oil is full, the piston 34 is inserted into the cylinder 28 of the fixed rod 26, and the piston is placed at a predetermined position, and then the rubber plug is inserted. Remove 36, and steel ball 2 here (taper hole 24e)
4f is press-fitted and the oil filling operation is completed.

Further, as another oil sealing method, the oil is sealed while immersing the fixed rod 26 including each member of the oil volume expansion absorption mechanism, the oil cylinder 24, and the end wall 24b in the oil. They may be assembled sequentially.

In FIG. 1, 40 is a shift lever, 41 is a shift jaw, 42 is a shift rod, 43 is a shift fork, 44 is a shift sleeve, and 45 and 46 are transmission gears.

Next, the operation of the transmission operating device will be described. The present device is configured as described above, and the pair of solenoid valves 12 and 13 are turned on and off.
When compressed air is supplied to and discharged from the pair of pressure chambers 9 and 10 by control, the power piston 5 strokes in the direction of arrow a or b in FIG. 1, and the piston rod 8 and the shift lever 40 move in the same direction. It moves and the transmission gears 45 and 46 are closed. At this time, the load of the power piston 5 increases until the synchronization mechanism mounted on the shift sleeve 44 completes the synchronization, so compressed air is stored in the pressure chamber 9 or 10.

On the other hand, when the shift operation is performed near the neutral position of the transmission, when the piston rod 8 operates, the oil in the oil damper 3 is moved to the position of the cylinder enlarged portion 24a formed substantially at the center of the oil cylinder 24 by the damper piston 25.
However, since the gap d ₁ between the cylinder enlarged portion 24 and the outer diameter portion of the damper piston 25 is wide here, the damping action becomes gentle and the damper piston 25 moves quickly. Therefore, the piston rod 8 moves quickly to reach the position immediately before the synchronization of the transmission gears. Corresponding to the position of the transmission gear immediately before synchronization, in the oil damper 3, the tip of the damper piston 25 passes through the enlarged cylinder portion 24 a of the oil cylinder 24 to reach a normal cylinder small diameter portion. Has become. After that, the gap between the oil cylinder 24 and the damper piston 25 becomes narrower, and the passage resistance when the oil passes through this narrow gap d ₂ causes a damping action on the piston rod 8 in the direction opposite to its stroke direction. To do. That is, the damping works effectively. Therefore, even after the synchronization of the transmission gears is completed, the load on the power piston 5 suddenly decreases, and even if the power piston 5 tries to accelerate rapidly, the damping action attenuates the acceleration of the piston rod 26 and the power piston 5, and the power piston 5 is quiet. The gear is turned on.

The inclined portions 24d formed at both ends of the cylinder expansion portion 24a of the oil cylinder 24 have different inclination angles.
The rate at which the two damping effects change can be determined as appropriate.

Next, since the oil volume expansion absorption mechanism due to heat generation due to the damping action of the damper oil shown in FIG. 2 is configured as described above, the volume expansion of the oil causes the piston 34 to move inside the cylinder 28. Is absorbed by sliding against the biasing force of the spring 35, and the pressure in the cylinder 28 does not rise much. It should be noted that the constant preload of the oil in the oil damper 3 by the spring 35 means that when the damper piston 25 strokes, one chamber of the cylinder 24 (this This is to prevent air from being sucked from the oil seal part due to the negative pressure generated in the right chamber.

FIG. 4 shows a cross section of another embodiment of the damper oil volume expansion absorbing mechanism. In the figure, one end 50a of the fixed rod 50 is fixed to the lot cover 27, and a hollow tube is formed on the other end 50b side. One end of the hollow portion 51 is connected to the oil cylinder through a communication hole 52. Communicated with 24. A plug screw 53 is screwed into the other end of the hollow portion 51 via an oil seal (not shown). Inside the hollow portion 51, a hollow ball 54 made of an elastic material in which air or another gas is sealed in one or a plurality (in the drawing, plural) is disposed. FIG. 5 shows a cross section of the hollow ball 54. Further, instead of the hollow ball 54, a hollow rod 55 made of an elastic material in which air or another gas is sealed may be provided in one or more of the hollow balls. FIG. 6 shows a vertical cross section of the hollow rod 55,
The vertical cross section in the right angle direction is the same as that in FIG. According to the damper oil volume expansion absorbing mechanism having such a configuration, the hollow ball 54 is wholly compressed by the pressure in the oil due to the volume expansion of the oil, and the shape thereof is reduced. To absorb. A preload is applied by screwing in the plug screw 53.

FIG. 7 shows a cross section of still another embodiment of the volume expansion absorbing mechanism of the damper oil. In the figure, the fixed rod
60 is almost the same as the fixed rod 50 in FIG. 3, except that a cap 62 made of an elastic material is sealed at the other end of the hollow portion 61 by a ring screw 63 so as to apply a preload.
According to the volume expansion absorbing mechanism having such a configuration, the cap 62 is inflated like a balloon by the pressure in the oil due to the volume expansion of the oil, and the volume expansion of the oil is absorbed here. Note that a bellows may be sealed instead of the cap 62.

Note that the technology of the present invention is not limited to the technology in the above-described embodiment, but may be implemented by means of another embodiment that performs the same function. Can be added.

g. Effects of the Invention As is clear from the above description, the transmission operating device of the present invention has the following effects.

The oil cylinder and damper piston built into the piston rod are designed to have two different damping effects. The power piston does not accelerate suddenly during and after synchronization. For this reason, the shift operation time is shortened, and even if the synchronization load is suddenly reduced after the synchronization of the transmission gears is completed, the piston rod does not suddenly accelerate, so that the gear can be shifted smoothly. Thus, damage to each part of the transmission due to impact can be prevented.

Further, since a means for absorbing volume expansion due to the temperature rise of the damper oil is provided inside the fixed rod of the damper piston, damage due to volume expansion due to heat generation of the damper oil, for example, internal pressure of the oil cylinder is reduced. It becomes abnormally high, and it is possible to prevent damage due to this.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view showing an embodiment of a transmission operating device of the present invention, FIG. 2 is an enlarged vertical sectional view of an oil damper and its oil volume expansion absorbing mechanism, and FIG. Explanatory drawing for explaining the method, FIGS. 4 and 7 are enlarged vertical sectional views showing another embodiment of the oil volume expansion absorbing mechanism of the oil damper, and FIG. 5 is a sectional view of the hollow ball shown in FIG. FIG. 6 is a vertical sectional view of the hollow rod. 3 ... Oil damper, 5 ... Power piston, 8 ... Piston rod, 9,10 ... Pressure chamber, 24 ... Oil cylinder, 24a ... Cylinder enlarged part, 25 ... Damper piston, 26,50,60 ...... Fixed rod, 28 ...... Cylinder, 32 ...... Piston, 35 ...... Spring, 40 ...... Shift lever. 51,61 …… hollow part, 51 …… hollow ball, 62 …… cap.

Claims (4)

(57) [Claims] 1. A power piston disposed in a power cylinder is connected to a shift lever of a transmission via a hollow piston rod, and compressed air is supplied to a pair of pressure chambers formed on both sides of the power piston. In a transmission operating device configured to selectively supply and discharge and operate the shift lever, an oil cylinder is fixedly disposed inside the piston rod, and the power piston is disposed inside the oil cylinder. A cylinder enlarged portion is formed at a position corresponding to the neutral position, a damper piston is slidably and gently fitted, and a damper oil volume expansion absorbing means by heat is provided inside a fixed rod of the damper piston. The volume expansion is absorbed by the volume change of the hollow portion of the volume expansion absorbing means which communicates with the oil cylinder, and the fixed roll is absorbed. A transmission operating device, wherein the damper piston is connected to a fixed side of the transmission operating device via a pad. 2. The means for absorbing volume expansion of damper oil due to heat includes a cylinder as the hollow portion, a piston slidably disposed in the cylinder, and moving the piston from the atmosphere side to the damper oil side. The transmission operating device according to claim (1), which comprises a spring that constantly urges. 3. A means for absorbing the volume expansion of damper oil by heat, wherein said means is a hollow spherical body or a hollow rod made of said hollow portion and one or more elastic members provided in said hollow portion and filled with air. The transmission operating device according to claim 1, comprising a body. 4. A method according to claim 1, wherein said means for absorbing volume expansion of damper oil by heat comprises said hollow portion and a cap made of an elastic material attached to an end of said hollow portion.
The transmission operating device according to the item.