JPS6237546A - Transmission operating device - Google Patents

Abstract

PURPOSE:To reduce a noise at the time of gear shifting, by installing a buffer position which presses a piston rod to a neutral direction from an intermediate position to a gearing completion position and thereby reduces output of this piston rod. CONSTITUTION:Both buffer pistons 31 and 32 installed in both end positions of a piston rod 16 are opposed to both piston rod end parts 16a and 16b, while both cylinder chambers 33 and 34 formed in the backside are connected to each discharge port of solenoid valves 24 and 23 by each of pipe lines 35 and 36. And, in the state that these buffer pistons 31 and 32 come into contact with stopper step parts 37a and 38a on each inner circumferential surface of cylinders 37 and 38, a clearance L2 equal to a stroke distance of up to an intermediate point between a synchronous completion position of a synchronizing mechanism and a engagement starting position of a clutch gear is constituted so as to be formed between both end parts 16a and 16b of the piston rod 16.

Description

[Detailed Description of the Invention] a. Field of Industrial Application The present invention relates to a transmission operating device for shifting mainly used in automobiles, etc., and particularly to a synchronizing load on a synchronizing mechanism during shifting of a transmission (when engaging a gear). With the rapid decline in
The present invention relates to an operating device that attenuates the shift force of a piston rod in order to prevent the piston rod of the transmission operating device from suddenly accelerating.

b. Prior Art and its Problems Operation of a transmission generally requires greater force for shift operation than for selection operation. For this reason, especially in buses and trucks that have large transmissions, transmission operating devices are installed so that smooth shifting operations can be performed with light force.

By the way, in a so-called synchronous type transmission in which the gears are synchronized and then engaged, a relatively large load for synchronization acts on the booster when the gears are engaged, but the load decreases rapidly after synchronization. For this reason, the piston rod of the operating device suddenly accelerates after synchronization, and as a result, there is a problem in that an impact is applied to the dog teeth of the transmission gear, producing noise.

The present invention has been devised to effectively solve the above-mentioned problems, and its purpose is to provide a transmission operating device that does not suddenly accelerate even after the biston rod passes a synchronous load. be.

Means for Solving Problem C1 An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a transmission operating device 1 according to the present invention.
The shift lever 3 of the operating device 1 projects downward into the transmission 2 from the opening 4 of the transmission housing, and the gear shift fork 5 inside the transmission 2 is operated by the shift lever 3. to perform the desired gear shift. In FIG. 1, 6 is a shifter rod, 7 is a retaining member, 8 is a drive shaft, 9 is a second gear, 10 is a third gear, and 11 is a shift sleeve.
A synchromesh mechanism (not shown) is incorporated into the shift sleeve 11.

A shift operation piston rod 16 is inserted into the cylinder 15 of the transmission operating device 1 . The shift lever 3 is rotatably attached to this piston rod 16,
The tip of the shift lever 3 is connected via a yoke 17 to a select operation piston rod (not shown). A fixed piston 18 is fixedly attached to the outer periphery of the piston wand 16 within the cylinder 15. A pair of left and right cylindrical free pistons 19 and 20 are disposed between the outer peripheral surface of the fixed piston 18 and the inner peripheral surface of the cylinder 15.

The pair of free pistons 19 and 20 are slidably arranged relative to the fixed piston 1 and the cylinder 15, respectively, and are driven by air pressure introduced into the pair of pressure chambers 2122 on both left and right sides of the fixed piston 18. A fixed piston 18 and a pair of free pistons 19 and 20 are adapted to be driven in the left-right direction in FIG. In Fig. 1, 14 is an air tank, which has a pair of pressure chambers 21 and 22.
The supply and discharge of compressed air to and from the pump are controlled by a pair of solenoid valves 23 and 24.

At the rear of the pair of free pistons 19.20, pressing steps 25.26 are formed, respectively, for pressing the ends of the fixed pistons. Further, an inward flange portion 27 is formed approximately at the center of the inner circumferential surface of the cylinder 15, and as shown in FIG. The fixed piston 18 is positioned at the neutral position (the position shown in FIG. 1). In this positioning state, the rear part of the free piston 19.20 and the cylinder 15
A predetermined gap I, 1 is formed between the end of the piston rod 16 and the end of the piston rod 1. ．． The configuration is such that the gear change of the transmission 2 is completed after one stroke.

Note that the stroke position of the piston rod 16 is detected by a stroke sensor (not shown).
The opening and closing of the pair of electromagnetic valves 23 and 24 is controlled based on the detection results of the stroke sensor.

A pair of buffer pistons 31 and 32 are disposed at both ends of the piston rod 16. These pair of damping pistons 31, 32 are located at the end 16a of the piston loft 16.

16b and is arranged to face the buffer piston 31.
The cylinder chambers 33, 34 formed behind the valves 32, 32 are connected by lines 35, 36 to the outlets of the solenoid valves 24, 23, respectively. Then, compressed air is introduced into the cylinder chambers 33, 34, and the buffer pistons 34, 32 move into the cylinder 3.
When in contact with the stopper step portions 37a, 38a on the inner circumferential surface of 7°38, there is a predetermined gap L between the end portions 16a, 16b of the piston loft 16 in the neutral state.

is configured so that it is formed. This gap L2 is
Specifically, as shown in Fig. 2, the stroke distance of the piston rod 16 is made to match the stroke distance from the neutral position to the midpoint between the synchronization completion position of the synchronization mechanism and the engagement start position of the clutch gear. It is composed of

J. Operation The transmission operating device 1 is constructed as described above, and when the operating device 1 is used to shift the transmission 2 from neutral to third as shown in FIG. 1, one solenoid valve 24 is turned OFF. Atmospheric air is introduced into the pressure chamber 22, and the other solenoid valve 23 is turned on to introduce compressed air into the pressure chamber 21. At this time, atmospheric air is introduced into one cylinder chamber 33 through a conduit 35, and compressed air is introduced into the other cylinder chamber 34 through a conduit 36. Therefore, the buffer piston 32 is pressed against the stopper step 38a by the pressure in the cylinder chamber 34.

When compressed air is introduced into the pressure chamber 21, the fixed piston 1
B and the piston rod 16 move to the right in FIG. 1, and as shown in FIG.
One end 16b abuts against the buffer piston 32. When the piston rod 16 comes into contact with the buffer piston 32, the pressure in the cylinder chamber 34 acts on the piston rod J6 via the buffer piston 32, so that the output of the piston rod 16 rapidly decreases as shown in FIG.

(The chain line in Figure 2 shows the output of the conventional device), and the stop clutch gear (not shown), which strokes further with this reduced output, begins to engage, and when it has stroked L+ from the neutral position, the gear Insertion is complete. Although the degree of reduction in the output of the piston loft 16 varies depending on the pressure receiving area of the buffer piston 32 (3i), the optimum pressure receiving area is determined according to the output of the transmission operating device.

In this way, the piston rod 16 strokes with the same output as the conventional operating device until the synchronization of the synchronization mechanism is completed, so that the synchronization is completed smoothly. On the other hand, after the synchronization is completed, the output of the piston loft 16 rapidly decreases, so the clutch gear engages quietly. Note that when the piston rod 16 strokes to the left in FIG. 1, the same operation as described above is performed.

Next, when returning from third to neutral (same for second to neutral), both solenoid valves 23 and 24 are turned on, and compressed air is introduced into the pair of pressure chambers 21.22 and cylinder chambers 33.34. . When compressed air is introduced into the pair of pressure chambers 21 and 22, the fixed piston 1 due to the difference in pressure receiving area by the free piston 20
8 and the piston rod 16 move from the right end position of the cylinder 15 in the neutral direction in FIG.
7, the neutral position is determined. (Situation shown in Figure 1). Note that when moving the fixed piston 18 and the piston port/second door 16 from the third (second) direction to the neutral direction, first one of the solenoid valves 24
Only (23) may be turned ON, and both electromagnetic valves 23 and 24 may be controlled to be turned ON during neutral positioning.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment and can be modified in various ways. For example, in the above embodiment, a pair of buffer pistons 31, 32
are arranged at both end positions of the piston rod 16, but the third
As shown in the figure, the piston rods 16 may be arranged all together at one end position. In this embodiment, one end 16c of the piston loft 16 is inserted into the insertion hole 39 of one buffer piston 31, and the piston rod 16 is When you stroke,
A dish-shaped portion 40 fixed to the tip thereof is brought into contact with the buffer piston 31 or 32.

Further, in the above embodiment, the buffer pistons 31 and 32 were brought into contact with the piston rod 16, but the power transmission mechanism from the piston rod 16 to the gear shift fork 5,
For example, it may be brought into contact with the shifter rod 6 or the like.

Furthermore, the present invention is not only applicable to an operating device of the type that introduces compressed air into the pressure chambers 21 and 22 through the electromagnetic valves 23 and 24 as in the above embodiments, but also applies to an operating device that is installed inside the piston rod 16, for example. A so-called booster type operating device that supplies and discharges compressed air to and from the pressure chambers 21 and 22 from supply and exhaust ports provided on the peripheral wall of the piston rod by opening and closing a valve mechanism connected to a change lever. It is also applicable to

As described above, the present invention provides the piston rod from an intermediate position between the synchronization completion position of the synchronization mechanism and the engagement start position of the clutch gear in the stroke of the piston rod in the gear engagement direction, to the gear engagement completion position. Since the system is equipped with a buffer piston that reduces the output of the piston rod by pushing it toward neutral, the piston rod does not suddenly accelerate after passing the synchronization completion position, and the clutch gear of the synchronization mechanism can be operated quietly. can be meshed with.

In addition, until the synchronization is completed, it has a relatively large output similar to the conventional one, so that the synchronization can be completed quickly and the speed of the speed change operation can be ensured.

In addition, in the present invention, the power transmission mechanism from the piston rod to the gear fork is brought into contact with the buffer piston to reduce the output of the piston rod, so the stroke position at which the protrusion of the piston rod decreases is extremely accurate. At the same time, the output is reduced instantaneously. Therefore, the present invention can be applied easily and with high reliability even to a transmission in which the width between the synchronization completion position and the clutch gear engagement start position in the stroke of the piston rod is relatively narrow.

Furthermore, since the present invention is based on a delicate configuration, it does not require any special control means, and because it is a relatively simple configuration, it can be realized at low cost, and it is hard to break down, so no special maintenance is required. .

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, in which Fig. 1 is a longitudinal sectional view of a transmission operating device, Fig. 2 is an output-stroke diagram of a piston rod, and Fig. 3 is a modification of the present invention. It is a longitudinal cross-sectional view of the end of a piston mouth and a door showing an example. 5... Gear shift fork, 6... Shifter rond, 8... Drive shaft, 11... Shift sleeve, 15... Cylinder, 16... Piston rod, 18... Fixed piston (piston) , 21, 22...
・Pressure chamber, 31, 32...Buffer piston, 33, 34...Cylinder chamber. Patent applicant Jidosha Kiki Co., Ltd. (and 2 others)

Claims (1)

[Claims] A gear shift system that operates a piston rod by supplying and discharging fluid pressure to a pair of pressure chambers formed on both sides of a piston, thereby driving a gear shift fork in the gear engagement direction or neutral direction via a power transmission mechanism. In the machine operating device, a pair of buffer pistons are brought into contact with the power transmission mechanism at an intermediate position between a synchronization completion position of the synchronization mechanism and an engagement start position of the clutch gear during a movement stroke of the power transmission mechanism in a gear engagement direction. A transmission operating device characterized in that the cylinder chamber of the buffer piston is provided in communication with the pressure chamber that moves the power transmission mechanism toward the buffer piston.