JPH063209Y2 - Actuator for gear transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an actuator for a gear transmission.

[Prior Art] As a device for reducing the load of gear shifting operation of a gear transmission in a vehicle, for example, there is one disclosed in Japanese Utility Model Laid-Open No. 57-42266. According to the above-mentioned device, the servo valve built in the actuator causes the actuator to operate in accordance with the operation amount of the shift lever, so that a light and quick shift operation corresponding to the operation speed of the manual operation of the disguise lever can be achieved.

However, particularly in the case of an actuator using pressurized air, the thrust force exerted on the piston by the pressurized air of about 4 kg / cm ² supplied to the actuator reaches 40 kg, and the synchronous action of the gears in the gear transmission ends. Even if the load of the actuator is lightened, the link mechanism is forcibly pulled because the thrust force equivalent to that at the time of the synchronous action acts on the piston. For this reason, unpleasant noise is generated due to the play of the link mechanism and the support rigidity. Further, the shift lever is forcibly tilted, which impairs the operation feeling. Such a problem phenomenon can be solved by, for example, reducing the diameter of the intake / exhaust port to reduce the air pressure to reduce the thrust of the piston or increasing the sliding resistance of the piston with respect to the cylinder. However, with such means, the boosting effect of the actuator is diminished, and the sense of operation is impaired.

[Problems to be Solved by the Invention] Therefore, an object of the present invention is to improve the feeling of operation and reduce noise by providing a conventionally installed component with a cushioning function. An object is to provide an actuator for a gear transmission.

[Means for Solving the Problems] In order to achieve the above object, the structure of the present invention has a piston rod for transmitting a shift operation force to a piston fitted in a cylinder, and a piston rod protruding from an end wall of the cylinder. An annular plate is externally attached to each end of the, and the end of the bellows-shaped large-diameter boot is locked to the cylinder end wall and the outer peripheral edge of the annular plate, and the end of the bellows-shaped small-diameter boot is inserted into the annular plate. The small-diameter boot is provided with a small-diameter portion that engages with the peripheral edge portion and the end of the piston rod and relatively slides against the piston rod at the end of the operation of the piston to generate a frictional drag force.

[Operation] At the end of the operation of the actuator, that is, at the end of the shift operation, the speed of the piston is suppressed due to the friction with the piston rod due to the reduction of the small-diameter boot. The shock is alleviated. As a result, generation of noise due to rattling of the link mechanism is suppressed and the operation feeling is improved.

[Embodiment of the Invention] As shown in FIG. 2, first, a remote type speed change operation mechanism equipped with a booster will be described. When the speed change lever 2 provided in the cab is selected (lateral tilt). While the lever 4 supported by the immovable shaft 3 is rotated, the lever 5 supported by the shaft 3 is rotated by a shift operation (tilt in the front-back direction) of the shift lever 2.

The levers 4 and 5 are connected to the levers 12 and 11 of the shaft 10 supported by the bracket 8 of the cab via the rings 7 and 6, respectively. The lever 11 has a bifurcated shape, and one end of the lever 11 and a lever 9 that interlocks with the lever 12 are coaxially aligned with a tilt shaft that connects the cab and the vehicle body via links 13 and 14, respectively. Levers 19 and 17
Connected to. The lever 19 is connected to the shaft 24 via the link 21.
The lever 25 and the bifurcated lever 17 are respectively connected to the lever 45 of the shaft 24 via a curved link.

A lever 22 that interlocks with the lever 25 is connected to a lever 35 of a shaft 36 via a link 26, an actuator 29 as a booster, and a link 30. A lever 37 interlocking with the lever 35 is connected to a lever 39 of a horizontal shaft 40 via a link 38. Lever 23 that interlocks with lever 45
Is connected to the lever 34 of the vertical shaft 33 via the link 27, and the lever 31 interlocking the lever 34 is connected to the link 4
4 is connected to the lever 42 of the vertical shaft 41.

The shaft 24 is supported by the vehicle body via the bracket 15, and similarly, the shafts 33 and 36 are also supported by the vehicle body. The vertical shaft 41 performs the select operation of the gear transmission 43 and the horizontal shaft 4
0 is configured to perform the shift operation of the gear transmission 43, respectively.

As is well known, the select operation of the speed change lever 2 achieves selective engagement with the shift block of the control rod in the gear transmission 43, and its operation force is light, but
The shift operation of the shift lever 2 requires a considerable amount of force to operate the known synchromesh mechanism in the gear transmission 43. Therefore, the actuator 29 as a booster device
Is supported by the vehicle body via a bracket 28, and the axial displacement of the link 26 transmitted from the shift lever 2 is transmitted to the link 30 by an actuator 29. Such remote control mechanisms are well known and will not be described further.

As shown in FIG. 1, an actuator 29 as a booster includes a cylinder 51 fixed to the vehicle body and a piston 52.
And the chambers 58 and 59 are partitioned. A hollow piston rod 65 is coupled to the piston 52, and both ends of the piston rod 65 are projected outward from the end wall 51 a of the cylinder 51. A known servo valve 60 is provided inside the piston rod 65, and the rod 26a connected to the above-described link 26 and the rod 30a connected to the link 30 are fitted to both ends of the piston rod 65. The rod 26a is provided with a passage 53 having an inlet 53a connected to the pressurized air tank and a passage 54 having an outlet 54a connected to the atmosphere. These passages 53, 54 are connected via a servo valve 60 in relation to the operation of the rod 26a. The piston rod 65 operates together with the piston 52 at this time, and the operation of the piston rod 65 causes the rod 3 to communicate with the chambers 58 and 59.
0a is transmitted. Therefore, the operation of the piston 52 operated by air pressure is transmitted to the rod 30a via the piston rod 65 by a slight operation force applied to the rod 26a by the speed change lever 2, and a light shift operation of the gear transmission 43 is obtained. To be The structure of such a servo valve 60 is disclosed in Japanese Utility Model Laid-Open No. 57-42266, and since it is not directly related to the gist of the present invention, its explanation is omitted.

According to the present invention, the dustproof boots A and B having a cushioning function are provided between the end wall 51a of the cylinder and the piston rod 65. The dustproof boot A has a large diameter boot 57 made of rubber or the like, one end of which is locked to the end wall 51a and the other end of which is locked to the metal annular plate 56, and one end of which is locked to the annular plate 56. It comprises a small diameter boot 55 whose end is locked to the end flange of the piston rod 65. The small-diameter boot 55 is formed in a bellows shape, and an intermediate small-diameter portion 55a is externally fitted onto the outer peripheral surface of the piston rod 65 so that the small-diameter boot 55 can be slidably contacted with the piston rod 6.
It is slidably contacted with the outer peripheral surface of 5.

The dustproof boot B includes a large diameter boot 57, a small diameter boot 55, and a boot 63. The end portion of the large diameter boot 57 is the end wall 5.
1a and a metal annular plate 56. Small boots 5
One end of the ring 5 is locked to the inner peripheral edge of the annular plate 56, and the other end is locked to the inner peripheral edge of the annular plate 61. One end of the ring 5 is slidably fitted onto the outer peripheral surface of the piston rod 65. Along with
The small-diameter portion 55a in the middle is also slidably fitted onto the outer peripheral surface of the piston rod 65. The boot 63 is locked between the annular plate 61 and the rod 30a.

Next, the operation of the gear transmission actuator according to the present invention will be described. Along with the shift operation of the speed change lever 2, the rod 26a is axially moved through the link mechanism, for example, the first
When pushed downward in the figure, pressurized air is supplied to the chamber 58 of the cylinder 51 via the servo valve 60, and the piston 5
The piston rod 65 is pushed downward together with 2. The upper large-diameter boot 57 is compressed in the initial stage of the operation of the piston rod 65, and the small-diameter boot 55 is compressed in the final stage of the operation when the annular plate 56 approaches the end wall 51a.

When the small-diameter boot 55 is compressed, the inner diameter of the small-diameter portion 55a is reduced and brought into close contact with the outer peripheral surface of the piston rod 65 to exert a damper effect. As shown in FIG.
The operating speed of 0a changes. That is, when the operation of the shift lever 2 is started, the synchronizing action of the synchromesh mechanism is started at the time point a, and the synchronizing action is ended at the time point b,
The load on the actuator 29 is reduced, the speed of the rod 30a is increased, and at time c, the dog teeth are engaged with each other. In the conventional example, the meshing ends at the time point d, and the operation of the piston is stopped at almost the same point e. At this time, the piston causes the clutch sleeve in the synchromesh mechanism to collide with the end wall of the dog tooth, generating not only noise but also impact on the link mechanism.
Noise is generated due to rattling of the connecting portion of the link mechanism.

However, according to the present invention, the rapid meshing of the dog teeth is suppressed as shown by the chain line in FIG. That is, at the end of the gear shifting operation, the piston rod 6 is rubbed with the piston rod 65 due to the reduction of the small diameter portion 55a of the small diameter boot 55 and the piston rod 6
Since the operation speed of No. 5 is suppressed, the impact at the end of the shift operation is alleviated, and thus the generation of noise due to rattling of the link mechanism is suppressed.

[Advantage of the Invention] According to the present invention, as described above, the piston rod for transmitting the shift operation force is coupled to the piston fitted in the cylinder,
An annular plate is externally inserted to each end of the piston rod protruding from the cylinder end wall, and the end of the bellows-shaped large-diameter boot is locked to the cylinder end wall and the outer peripheral edge of the annular plate to form a bellows-shaped small-diameter boot. The small-diameter boot is provided with a small-diameter portion that engages the inner peripheral edge portion of the annular plate and the end portion of the piston rod with the end portion of the annular plate to generate a frictional resistance by sliding contact with the piston rod at the end of the piston operation. Therefore, when the small-diameter boot is compressed, the piston rod is strongly frictionally engaged with the piston rod, whereby frictional resistance acts on the piston rod at the end of the shift operation, and the operating speed of the piston rod is suppressed.

Therefore, the impact of the piston rod at the final stage of the shift operation is mitigated, rattling due to the impact of the link mechanism is suppressed, and noise can be reduced.

In the operation of the shift lever, at the end of the shift operation, the operating force from the actuator is transmitted to the shift lever,
The problem of impairing the operation feeling is solved.

Since the cushioning mechanism is configured by changing the dustproof boot that has been installed in the past, it is possible to install it easily without changing the structure of the conventional cylinder or piston rod at a slight cost. Is.

[Brief description of drawings]

FIG. 1 is a plan sectional view of an actuator for a gear transmission according to the present invention, FIG. 2 is a perspective view showing a remote control mechanism of a gear transmission equipped with the same actuator, and FIG. It is a diagram. A, B: Dustproof boots, 26a, 30a: Rod, 29:
Actuator, 51: Cylinder, 52: Piston, 5
5: boots, 55a: small diameter part, 60: servo valve, 65:
Piston rod

Claims (1)

[Scope of utility model registration request] Claim: What is claimed is: 1. A piston fitted in a cylinder is connected to a piston rod for transmitting a gear shift operation force, and an annular plate is externally fitted to each end of the piston rod projecting from the cylinder end wall to form a bellows-shaped large-diameter boot. The end of the piston is locked to the cylinder end wall and the outer peripheral edge of the annular plate, and the end of the bellows-shaped small-diameter boot is locked to the inner peripheral edge of the annular plate and the end of the piston rod. An actuator for a gear transmission, characterized in that the small-diameter boot is provided with a small-diameter portion that relatively slides against the piston rod to generate a frictional drag force.