JPH0743537Y2 - Gear change device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a speed change device suitable for a vehicle speed change mechanism.

2. Description of the Related Art Conventionally, a plurality of sets of transmission gear trains having different rotation ratios are provided between a drive shaft and a driven shaft, and any one of these transmission gear trains is selectively connected to a driven shaft to achieve a desired transmission gear train. In a transmission that obtains rotation transmission according to a gear ratio, a dock clutch, a sliding gear, and
A synchro mesh mechanism, a hydraulic multi-plate clutch, etc. are used.

Among these selective coupling means, the one in which the driven shaft-side transmission gear meshing with the transmission shaft-fixed transmission gear and the driven shaft are detachably connected using a dock clutch have a simple structure. It is widely used because of its low cost and reliable transmission of rotation.

However, it is not easy to separate the drive side claw of the dock clutch and the driven shaft claw from each other in the state of transmitting the rotation of the driving force, and it is necessary to stop the rotation and then remove the claw. I have to. Therefore, when the dock clutch is used as a transmission for a vehicle, the shifting operation can be performed only after the traveling of the vehicle is temporarily stopped.

On the other hand, when the hydraulic multi-plate clutch is used, the intermittent power transmission can be performed smoothly, but there is a drawback that the transmission becomes large and the cost becomes high.

Means for Solving the Problems A first rotary body 16 and a second rotary body 14 that rotate independently by power from a drive unit are rotatably provided on a driven shaft 7, and the first rotary body A first clutch claw 18 is formed on the outer peripheral side of the side end surface of the body and a first beveled cam claw 19 is formed on the inner peripheral side, and a second clutch claw 18 that engages with the first clutch claw 18 in a disengageable manner is formed. A clutch claw body 20 having a clutch claw 21 and biased in a direction in which the first and second clutch claws 18, 21 are engaged with each other is slidably spline-fitted onto the driven shaft 7 and the clutch claw is provided. A bearing sleeve in which a cam claw body 24 is rotatably fitted to the side of the first rotating body 16 of the body 20 and is rotatably fitted to the driven shaft 7.
The cam claw body 23 is spline-fitted to the shaft 11 to interrupt the power transmission from the second rotary body 14 to the cam claw body 23, and at the time of power transmission, the second rotary body 14 and the cam claw body 23.
Is provided with a power transmission connecting / disconnecting portion 10 for integrally rotating the cam claw body 23 and the cam claw body 23 with the first sloped cam claw 19 having a sloped surface when driven by the second rotary body 14. A second slanted cam pawl 24 is formed on the cam pawl body 23 so as to be axially moved together with the clutch pawl body 20 and fixedly meshed in the rotational direction when driven from the first rotating body 16 side. The cam claw body 23 is formed with a convex portion 25 that is fitted in the groove portion of the second clutch claw 21 of the body 20 so as to be rotatable within a set angle and protrudes toward the outer peripheral direction.

In the state where the power transmission interrupting portion 10 is operated to interrupt the power transmission from the second rotary body 14 to the cam pawl body 23, the clutch pawl body 20 and the cam pawl body 23 are located on the first rotary body 16 side. The second clutch claw of the clutch claw body 20 is being urged to slide by
21 and the first clutch claw 18 of the first rotary body 16 mesh with each other, and the second sloped cam claw 24 of the cam claw body 23 and the first rotary body
Sixteen first inclined surface cam pawls 19 mesh with each other. Then, the first rotary body 16 and the clutch pawl body 20 rotate integrally due to the meshing of the first and second clutch pawls 18 and 21, and the driven shaft 7 reaches the rotational speed of the first rotary body 16. Rotate accordingly.

When the power transmission interrupting portion 10 is operated to transmit the power from the second rotating body 14 to the cam claw body 23, the cam claw body 23 becomes the second rotating body.
Rotate integrally with 14. Then, due to the difference in rotational speed between the second rotary body 14 and the first rotary body 16, the cam claw body 23 has a direction in which the first and second sloped cam claws 19 and 24 are disengaged from each other. Force acts to move the cam claw body 23 in a direction away from the first rotating body 16. As a result, the clutch claw body 20 pushed by the cam claw body 23 also moves to the first and second clutch claws 18,2.
Slide in the direction to release the meshing of one. When the first and second clutch claws 18 and 21 and the first and second beveled cam claws 19 and 24 are disengaged from each other, the protrusion 25 is rotated by the rotation of the cam claw 23. The second claw 21 of the body 20 comes into contact with the rear side surface of the mountain portion of the second claw 21 in the direction of rotation, the clutch claw body 20 rotates integrally with the cam claw body 23, and the driven shaft 7 rotates the second rotating body 14. Rotate according to the number. At this time, the cam claw 23 is advanced with respect to the clutch claw 20, and between the second claw 21 of the clutch claw 20 and the second beveled cam claw 24 of the cam claw 23. A phase difference is generated. Therefore, when the first and second clutch claws 18 and 21 face each other in a meshable state, the first and second sloped cam claws 19 and 24 face each other in a non-meshed state. And the second sloped cam pawls 19 and 24 face each other in a meshable state, the first and second clutch pawls 18 and 21 face each other in a non-meshed state, and the first and second clutches. Nails 18,21
Repeated engagement and disengagement of the cam pawls 19 and 24 with each other and the first and second cam cams 19 and 24 with slopes are prevented.

When the power transmission interrupting portion 10 is operated to interrupt the power transmission from the second rotary body 14 to the cam pawl body 23, the cam pawl body 23 becomes rotatable. On the other hand, the clutch claw body 20 rotates by the inertial force together with the driven shaft 7, and the cam claw body 23 relative to the clutch claw body 23.
Is canceled and the phase difference between the second clutch claw body 21 of the clutch claw body 20 and the second sloped cam claw 24 of the cam claw body 23 disappears. And the first and second clutch nails
The clutch pawl body 20 and the cam pawl body 23 are arranged on the first rotary body 16 side at a timing when 18,21 and the first and second sloped cam pawls 19 and 24 face each other in a state where they can mesh with each other. Slides by the urging force to the first and second clutch claws
18,21 and the first and second sloped cam pawls 19,24 are in mesh with each other. Therefore, the first and second clutch claws 1
The first rotating body 16 and the clutch claw body 20 rotate integrally with each other due to the meshing of 8, 21, and the driven shaft 7 rotates again according to the number of rotations of the first rotating body 16.

Embodiment An embodiment of the present invention will be described with reference to the drawings. An input shaft 4 supported by the bearings 2 and 3 and an output shaft 7 which is a driven shaft supported by the bearings 5 and 6 are housed in the mission case 1 of the tractor with parallel axes. The input shaft 4 is connected to an engine (not shown) that is a drive unit, and the output shaft is connected to front wheels (not shown). Also, the input shaft 4
A small-diameter gear 8 and a large-diameter gear 9 are integrally formed with each other.

On the output shaft 7, a wet friction clutch 10 as a power transmission connecting / disconnecting portion and a bearing sleeve 11 are rotatably fitted, and the meshing joint portion 12 and the bearing sleeve 11 formed on the wet friction clutch 10 are formed. The meshed joint portion 13 is meshed. Further, on the outer peripheral portion of the bearing sleeve 11, there is provided a gear 14, which is a second rotating body, which meshes with the gear 9 and transmits a rotational force from the input shaft 4 to the wet friction clutch 10 via a bearing 15. A gear 16, which is a first rotating body that is supported and meshes with the gear 8, is supported via a bearing 17. A first clutch claw 18 is radially formed on the outer peripheral portion of one side end surface of the gear 16, and a first sloped cam claw 19 is radially formed on the inner peripheral portion of the same side end surface. The claw top of the first beveled cam claw 19 is the first clutch claw.
It is set higher than or equal to the height of 18 nails.

A clutch claw body 20 is slidably fitted on the output shaft 7 in a slidable manner, and a second clutch claw 21 is formed on a side end surface of the clutch claw body 20 so as to mesh with the first clutch claw 18 in a disengageable manner. Has been done. In addition, the clutch claw 20 in the direction in which the first and second clutch claws 18 and 21 mesh with each other.
A spring 23 for urging is provided on the output shaft 7.

Next, there is provided a cam claw body 23 slidably fitted to the outer peripheral portion of the bearing sleeve 11 and located between the gear 16 and the clutch claw body 20. The cam claw body 23 is formed with a second sloped cam claw 24 that engages with the first sloped cam claw 19 in a disengageable manner and extends into the groove portion of the second clutch claw 21. The convex portion 25 is formed so as to project in the outer peripheral direction. The width of the convex portion 25 is set to be smaller than the width of the groove portion of the clutch claw body 20, and the clutch claw body 20 and the cam claw body 23 are provided so as to be relatively rotatable within a set angle. Has been. Further, the clutch claw body 20 and the cam claw body
The side end surfaces facing each other with 23 are always in contact with each other, and both side end surfaces are finished to be smooth.

In such a structure, FIG. 1 shows a low speed transmission state, and the wet friction clutch 10 is not operating. Then, the second clutch claw 21 in the clutch claw body 20 and the second sloped cam claw 24 in the cam claw body 23 are in phase with each other, and the clutch claw body 20 is moved by the biasing force of the spring 23. The first and second clutch pawls 18 and 21 are struck together with the cam pawl 23 on the gear 16 side, and the first and second sloped cam pawls 1 as shown in FIG. 4 (a).
9,24 are meshed with each other. Further, as shown in FIG. 3 (a), the side surface on the front side in the rotation direction of the mountain portion of the first clutch claw 18 is in contact with the side surface on the rear side in the rotation direction of the convex portion 25. Here, when the input shaft 4 is rotated by the power from the engine, the gear 16 meshing with the gear 8 rotating integrally with the input shaft 4 is rotated, and the first and second sloped cam pawls 19, 2 are formed.
The cam claw 23 is rotated integrally with the gear 16 by the meshing of the four, and the clutch claw 20 is rotated integrally with the gear 16 by the meshing of the first and second clutch claws 18, 21. Then, the clutch pawl 20 and the output shaft 7 rotate integrally to transmit power to the front wheels.

Since the bearing sleeve 11 rotates integrally with the cam claw 23, the meshing joint portion 12 of the wet friction clutch 10 meshing with the meshing joint portion 13 of the bearing sleeve 11 idles integrally with the bearing sleeve 11. ing. Also, the gear 14 that meshes with the gear 9
However, since the wet friction clutch 10 is not operating, the gear 14 is idling.

Next, FIG. 2 shows a high speed transmission state, in which the wet friction clutch 10 is operating. When the wet friction clutch 10 is operated, the rotation of the gear 14 is transmitted to the meshing joint portion 12 of the wet friction clutch 10, and the bearing sleeve 11 is rotationally driven by the meshing of the meshing joint portions 12 and 13. Then, the cam claw 23 rotates integrally with the bearing sleeve 11,
The rotation speed of the cam pawl 23 at this time is higher than the rotation speed of the gear 16. Due to the difference in the number of rotations, the cam claw body 23 receives a force in a direction away from the gear 16 and the cam claw body 23
Is advanced with respect to the gear 16 and the clutch pawl 20 and the cam pawl 23 is advanced with respect to the gear 16 and the clutch pawl 20 by 24 ° as shown in FIG. 4 (b). The engagement between the second sloped cam pawls 19 and 24 is released. Further, the cam claw body 23 slides in a direction in which the pushed claw claw body 20 is separated from the gear 16, and as shown in FIG. 4 (b), the first and second clutch claws 18, 21 also mesh with each other. It will be canceled. Then, when the cam pawl 23, which rotates at a higher speed than the clutch pawl 20, advances by a set angle (30 °) with respect to the clutch pawl 20, as shown in FIG. The front side surface contacts the rear side surface in the rotation direction of the mountain portion of the second clutch claw 21, and thereafter, the clutch claw body 20 becomes the cam claw body.
By receiving the force from 23, it is rotationally driven integrally with the cam claw 23 as shown in FIGS. Then, the output shaft 7 rotates integrally with the clutch pawl 20 and the front wheels are rotationally driven at high speed.

Here, when power is transmitted at a high speed through the wet friction clutch 10, the cam claw body 23 is rotating with the set angle advanced from the clutch claw body 20. For this reason, as shown in FIG.
The cam claw 24 with the second slope of the cam claw body 23 is advanced by 120 °.
And the first beveled cam claw 19 of the gear 16 face each other so that they can mesh with each other, the top of the second clutch claw 21 of the clutch claw body 20 and the top of the first clutch claw 18 of the gear 16 The cam claw 23 does not slide to the gear 16 side together with the clutch claw 20 due to the biasing force of the spring 22, and the first and second sloped cam claws 19 and 24 mesh with each other. Does not happen. Further, as shown in FIG. 4 (g), the cam claw 23 advances from the gear 16 by 150 °, and the second clutch claw 21 of the clutch claw 20 and the first clutch claw 18 of the gear 16 are separated from each other. When facing each other in a meshable state,
The top of the second beveled cam pawl 24 of the cam pawl 23 is in contact with the top of the first beveled cam pawl 19 of the gear 16, and the clutch pawl 20 is cammed by the biasing force of the spring 22. It does not slide to the gear 16 side together with the claw body 23, and the first and second clutch claws 18 and 21 do not mesh with each other. Therefore, the first and second sloped cam pawls 19 and 24 and the first and second clutch pawls 18 and 21 are repeatedly meshed with each other, so that noise and wear are not generated, and the output shaft 7 is Continue rotation in high speed transmission.

When the operation of the wet friction clutch 10 is stopped, the cam claw body 23
The driving force that was rotating is lost, the bearing sleeve 11 and the cam claw 23 are in a rotatable state, and the clutch claw 20 rotates together with the output shaft 7 by inertial force. Then, the clutch claw body 20 gradually advances with respect to the cam claw body 23, and after advancing the set angle, the side surface of the second clutch claw 21 on the front side in the rotational direction of the mountain portion is the side surface on the rear side in the rotational direction of the convex portion 25. The second clutch claw 21 and the second sloped cam claw 24 are in phase with each other. Therefore, the first and second clutch claws 1
When 8 and 21 face each other so that they can mesh with each other, the first and second sloped cam pawls 19 and 24 also face each other so that they can also mesh, and at this time, the clutch pawls are pressed by the biasing force of the spring 22. The body 20 slides to the gear 16 side together with the cam claw body 23, and the first and second sloped cam claws 19 and 24 and the first and second clutch claws 18 and 21 mesh with each other. Then, the rotation of the input shaft 4 is transmitted to the output shaft 7 via the gears 8 and 16 and the clutch pawl 20 and returns to the low speed transmission state.

In addition, in the present embodiment, the transmission which is in the high speed transmission state when the wet friction clutch 10 is operated and is in the low speed transmission state when the operation of the wet friction clutch 10 is stopped has been described. Alternatively, the transmission may be in a low speed transmission state when the wet friction clutch 10 is operated by changing the number of teeth of 9 and 9.

Effect of the Invention As described above, according to this invention, the second beveled cam pawl 24 of the cam pawl 23 and the first beveled cam pawl 19 of the first rotating body 16 are engaged with each other, and the clutch pawl 20 is provided. Second clutch nail
21 and the first clutch claw 18 of the first rotary body 16 are engaged with each other, and the rotation of the first rotary body 16 is transmitted to the driven shaft 7 via the clutch claw body 20. A cam claw member 23 that rotates integrally with the second rotating body 14 during a gear shift operation in which the interrupting portion 10 is operated to rotate the second rotating body 14.
And the first rotating body 16 by the difference in the number of rotations, the first and second sloped cam pawls 19 and 24 are moved in a direction in which the cam pawls 23 are disengaged, and the clutch pawl body 20 is moved. Sliding to release the engagement between the first and second clutch pawls 18 and 21, and further rotating the clutch pawl body 20 integrally with the cam pawl body 23 via the convex portion 25 of the cam pawl body 23. This allows smooth and reliable gear shifting, and
In order to generate a phase difference between the second beveled cam claw 24 of the cam claw 23 and the second clutch claw 21 of the clutch claw body 20 during power transmission through the second rotating body 14. It is possible to prevent the generation of noise and wear due to the repeated meshing of the first and second beveled cam pawls 19 and 24 and the first and second clutch pawls 18 and 21. When the operation of the transmission / interruption portion 10 is stopped to return to the normal power transmission state, the cam claw body 23 which is rotatable by stopping the operation of the power transmission / interruption portion 10 is integrated with the driven shaft 7 by the inertial force. The clutch claw body 20 rotating at an advanced angle advances to eliminate the phase difference between the second clutch claw 21 of the clutch claw body 20 and the second beveled cam claw 24 of the cam claw body 23 to eliminate the first and the second. The second clutch pawls 18 and 21, and the first and second sloped cam pawls 1
The 9,24 gears can be engaged with each other to smoothly and reliably shift gears to the normal power transmission state.
20 and the cam claw 23, the first and second clutch claws 18, 21 and the first and second sloped cam claws 1 are provided only on one side end surface.
Since 9,24 are formed, the processing can be easily performed and the cost can be reduced.

[Brief description of drawings]

The drawings show an embodiment of the present invention. FIG. 1 is a vertical sectional side view showing a low speed transmission state, FIG. 2 is a vertical sectional side view showing a high speed transmission state, and FIG. FIG. 4 is an explanatory view showing the angular state, and FIG. 4 is an explanatory view showing the advanced state of the cam claw body with respect to the gear and the positional relationship between the cam claws and the clutch claws at that time. 7: driven shaft, 10: power transmission interrupted part, 11: bearing sleeve, 14: second rotary body, 16: first rotary body, 18 ...
… First clutch claws, 19 …… First sloped cam claws, 20…
… Clutch claw body, 21 …… Second clutch claw, 23 …… Cam claw body, 24 …… Second slanted cam claw, 25 …… Convex part

Claims (1)

[Scope of utility model registration request] 1. A driven shaft 7 comprising a first rotating body 16 and a second rotating body 14 which rotate independently of each other by power from a drive unit.
Rotatably provided on the upper side, a first clutch claw 18 is formed on the outer peripheral side of the side end surface of the first rotating body 16, and a first beveled cam claw 19 is formed on the inner peripheral side. Clutch claw
A clutch claw body 20 having a second clutch claw 21 that engages with and disengages from the clutch 18 and is biased in a direction in which the first and second clutch claws 18 and 21 are engaged with each other is slid on the driven shaft 7. The clutch claw body 20 is freely spline-fitted, and the cam claw body 23 is rotatably fitted to the first rotary body 16 side of the clutch claw body 20, and the bearing sleeve 11 is rotatably fitted to the driven shaft 7. The cam pawl 23 is spline-fitted to intermittently transmit power from the second rotary body 14 to the cam pawl 23, and at the time of power transmission, the second rotary body 14
And a power transmission interrupting portion 10 for integrally rotating the cam claw body 23 with each other, and when driving from the second rotating body 14 side, meshes with the first sloped cam claw 19 having a sloped surface. When the cam pawl 23 is moved in the axial direction together with the clutch pawl 20 and is driven from the first rotating body 16 side, the second beveled cam pawl 24 is fixedly meshed in the rotational direction with the cam pawl 24.
Formed on the cam claw body 23 by projecting in the outer peripheral direction a convex portion 25 that is formed in the groove 23 of the clutch claw body 20 and is rotatably fitted within a set angle in the groove portion of the second clutch claw 21. A gear shift device characterized by the above.