JPH0743536Y2 - 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 and the driven-side claw of the dock clutch in the state where the driving force is transmitted, and the claw must be separated after the rotation is stopped. 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 and 21 are engaged with each other is slidably spline-fitted onto the driven shaft 7 and the clutch claw is provided. Body 20
A bearing sleeve in which a cam claw 24 is rotatably fitted to the first rotating body 16 side of the above and is rotatably fitted to the driven shaft 7.
The cam pawl 24 is spline-fitted to the shaft 11 to intermittently transmit power from the second rotary body 14 to the cam pawl 24, and at the time of power transmission, the second rotary body 14 and the cam pawl 24
Is provided with a power transmission connection / disconnection portion 10 for integrally rotating the cam claw body 24 and the first cam cam claw 19 with a slope when the second rotary body 14 is driven. A second slanted cam pawl 25 is formed on the cam pawl body 24 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. A convex portion 26 that fits rotatably within a set angle in the groove portion of the second clutch pawl 21 in the body 20 is formed on the cam pawl body 24 by protruding in the outer peripheral direction, and at the same time, the clutch pawl body 20 and the clutch pawl body 20 and the A spring 28 is stretched between the protrusion 26 and the clutch claw 20 in the direction of rotation.

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 24, the clutch pawl body 20 and the cam pawl body 24 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 25 of the cam claw body 24 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 rotary body 14 to the cam pawl body 24, the cam pawl body 24 becomes the second rotary body.
Rotate integrally with 14. Then, due to the difference in rotation speed between the second rotary body 14 and the first rotary body 16, the cam claw body 24 is in a direction in which the first and second sloped cam claws 19, 25 are disengaged from each other. Is applied to move the cam claw 24 in a direction away from the first rotating body 16. As a result, the clutch claw body 20 pushed by the cam claw body 24 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 25 are disengaged from each other, the protrusion 26 is formed by the rotation of the cam claw 24. The second claw 21 of the body 20 comes into contact with the side surface of the mountain portion of the second claw 21 on the rear side in the rotation direction, the clutch claw body 20 rotates integrally with the cam claw body 24, and the driven shaft 7 rotates the second rotating body 14. Rotate according to the number. At this time, the cam claw body 24 is advanced with respect to the clutch claw body 20, and between the second clutch claw 21 of the clutch claw body 20 and the second beveled cam claw 25 of the cam claw body 24. 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 25 face each other in a non-meshed state. And the second beveled cam pawls 19, 25 face each other in a meshable state, the first and second clutch pawls 18, 21 face each other in a non-meshed state, and the first and second clutches. Nails 18,2
Repeated engagement and disengagement of the one and the first and second sloped cam claws 19 and 25 are prevented.

When the power transmission interrupting portion 10 is operated to interrupt the power transmission from the second rotating body 14 to the cam pawl 24, the cam pawl 24 becomes rotatable and the cam pawl 24 is stretched by the spring 28. It is returned in the direction opposite to the direction it was rotating. When the cam claw 24 is returned to the direction opposite to the rotation direction by the set angle, the phase difference between the second beveled cam claw 25 of the cam claw 24 and the second clutch claw 21 of the clutch claw 20 disappears. . Then, the first and second clutch claws 18, 21 and the first and second beveled cam claws 19, 25 are opposed to each other in a meshable state at the same time with the clutch claw body 20 and the cam claw body. 24 slides by the urging force to the first rotating body 16 side, the first and second clutch claws 18 and 21 and the first and second sloped cam claws 19 and 25 to each other. Mesh with each other. Therefore, the first rotating body 16 and the clutch claw body 20 are integrally rotated by the engagement of the first and second clutch claws 18 and 21, and again,
The driven shaft 7 rotates 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. On the outer peripheral portion of the bearing sleeve 11, a gear 14 that is a second rotating body that meshes with the gear 9 and transmits a rotational force from the input shaft 4 to the wet friction clutch 10 is mounted 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 by a spline, and a second clutch claw 21 meshing with the first clutch claw 18 in a disengageable manner is attached to a side end surface of the clutch claw body 20. Formation Further, a protrusion 22 for hooking one end of a spring described later is formed on the outer peripheral portion of the clutch claw body 20. Also, the first and second clutch nails
A spring 23 is provided on the output shaft 7 for urging the clutch claw body 20 in a direction in which 18, 21 mesh with each other.

Next, there is provided a cam claw body 24 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 24 is formed with a second cam cam claw 25 with a bevel that engages with the first cam claw 19 with a bevel in a disengageable manner, and extends into the groove of the second claw 21. The convex portion 26 is formed so as to project in the outer peripheral direction, and the protruding portion 27 is formed at the tip of the convex portion 26. A spring 28 is stretched between the protrusion 27 and the protrusion 22 in the rotational direction of the clutch pawl 20 and the cam pawl 24. The width of the convex portion 26 is set to be smaller than the width of the groove portion of the clutch claw body 20.
20 and the cam claw 24 are provided so as to be relatively rotatable within a set angle. Further, the mutually facing side end surfaces of the clutch claw body 20 and the cam claw body 24 are always in contact with each other, and both of these side end surfaces are finished to be smooth surfaces.

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 25 in the cam claw body 24 are in phase with each other, and the clutch claw body 20 is urged by the urging force of the spring 23. It slides to the gear 16 side together with the cam claw 24, and as shown in FIG. 4 (a), the first and second clutch claws 18 and 21, and the first and second sloped cam claws 1
9,25 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 26. 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 24 is rotated integrally with the gear 16 by the meshing of the five, 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 24, 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 24 rotates integrally with the bearing sleeve 11,
The rotation speed of the cam pawl 24 at this time is higher than the rotation speed of the gear 16. Due to the difference in the number of rotations, the cam pawl 24 receives a force in a direction away from the gear 16 and the cam pawl 24
Is advanced with respect to the gear 16 and the clutch pawl 20 and the cam pawl 24 is advanced with respect to the gear 16 and the clutch pawl 20 by 25 ° as shown in FIG. 4 (b). The meshing between the second sloped cam pawls 19 and 25 is released. Further, the clutch claw body 20 pushed by the cam claw body 24 also slides in the direction away 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 24 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.
Upon receiving a force from 24, the cam claw 24 is rotated integrally with the cam claw 24 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. At this time, since the projection 27 of the cam claw 24 is maintained in a state where the projection 27 of the cam claw 24 is advanced by the set angle with respect to the projection 22 of the clutch claw 20, the spring 28 is moved as shown in FIG. 5B. It has been stretched.

Here, when power is transmitted at a high speed through the wet friction clutch 10, the cam claw body 24 is rotating with the set angle advanced from the clutch claw body 20. For this reason, as shown in FIG.
The cam claw 25 with the second slope of the cam claw body 24 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 24 does not slide to the gear 16 side together with the clutch claw 20 due to the urging force of the spring 23, and the first and second sloped cam claws 19, 25 mesh with each other. Does not happen. Further, as shown in FIG. 4 (g), the cam claw 24 advances by 150 ° from the gear 16 so that the second clutch claw 21 of the clutch claw 20 and the first clutch claw 18 of the gear 16 move. When facing each other in a meshable state,
The top of the second beveled cam pawl 25 of the cam pawl 24 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 23. It does not slide to the gear 16 side together with the claw body 24, and the first and second clutch claws 18 and 21 do not mesh with each other. Accordingly, the first and second sloped cam pawls 19 and 25 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 24
The driving force that has been rotating disappears, and the bearing sleeve 11 and the cam claw 24 become rotatable. Then, the urging force of the spring 28 causes the cam pawl body 24 to return in the direction opposite to the rotating direction. Then, when the side surface on the rear side in the rotation direction of the convex portion 26 is returned to the position where it comes into contact with the side surface on the front side in the rotation direction of the mountain portion of the second clutch claw 21, the clutch claw body.
The advanced state of the cam claw body 24 with respect to 20 is canceled, and the second clutch claw 21 of the clutch claw body 20 and the second sloped cam claw 25 of the cam claw body 24 are in phase with each other. Therefore, when the first and second clutch claws 18 and 21 face each other so that they can mesh with each other, the first and second sloped cam claws 19 and 25 also face each other so that they can mesh with each other. The clutch claw body 20 is moved by the urging force of the spring 23 together with the cam claw body 24 into the gear 16
It slides to the side, and the first and second sloped cam claws 19 and 25 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 25 of the cam pawl 24 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 pawl body 24 that rotates integrally with the second rotary body 14 during a gear shift operation in which the interrupting portion 10 is operated to rotate the second rotary body 14
And the first rotating body 16 due to the difference in the number of rotations, the first and second sloped cam claws 19 and 25 are moved in a direction in which the cam claws 24 are disengaged from each other and the clutch claw 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 24 via the convex portion 26 of the cam pawl body 24. This allows smooth and reliable gear shifting, and
To generate a phase difference between the second beveled cam claw 25 of the cam claw body 24 and the second clutch claw 21 of the clutch claw body 20 during power transmission via the second rotating body 14. It is possible to prevent the occurrence of noise and wear due to the repeated meshing of the first and second beveled cam pawls 19, 25 with each other and the first and second clutch pawls 18, 21 with each other. When the operation of the transmission / interruption portion 10 is stopped to return to the normal power transmission state, the cam pawl body 24, which is rotatable by stopping the operation of the power transmission / interruption portion 10, is rotated by the pulling force of the spring 28. It is possible to return in the opposite direction, whereby the advance state of the cam claw body 24 with respect to the clutch claw body 20 is canceled and the first and second sloped cam claws 19 and 25, and the first and second claws. The clutch claws 18 and 21 of the two must face each other so that they can be engaged with each other. Slope with a cam claw of
There is an effect such that the gears 19, 25 and the first and second clutch pawls 18, 21 can be quickly engaged with each other to smoothly and reliably perform the shift to the normal power transmission state.

[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, 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, and FIG. 5 is a low speed transmission state and a high speed transmission state. FIG. 6 is an explanatory view showing a stretched state of the spring in FIG. 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 body, 24 …… Cam claw body, 25 …… Second slanted cam claw body, 26 …… Convex part, 28 ……
spring

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 24 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 24 is spline-fitted to intermittently transmit power from the second rotary body 14 to the cam pawl 24, and at the time of power transmission, the second rotary body 14
And a power transmission connecting / disconnecting portion 10 for integrally rotating the cam claw body 24 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 24 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 25 is fixedly meshed in the rotational direction with the cam pawl 25.
24 is formed on the cam claw body 24 by projecting a convex portion 26 that is fitted in the groove portion of the second clutch claw 21 of the clutch claw body 20 to be rotatable within a set angle in the outer peripheral direction. At the same time, a spring 28 is stretched between the clutch pawl 20 and the convex portion 26 so as to extend in the rotational direction of the clutch pawl 20.