JP2019158085A - Seamless shift type transmission - Google Patents

Abstract

To prevent collision noise generated when dog teeth of a present shift stage move away from a drive tooth surface and come in contact with a coast tooth surface due to an occurrence of a differential rotation during shifting from the present shift stage to a next shift stage.SOLUTION: A seamless shift type transmission includes: speed change gear pairs 11in and 11out, 12in and 12out, and 13in and 13out; a dog clutch mechanism 3; a shift operation mechanism 4; and a dog tooth disengaging can mechanism 5. A shifting cam mechanism 48 by a combination of a drum groove 42 formed in a shifting drum 41 and a bracket pin 46 connected to a shift fork 45 that engages with a sleeve dog 32, and arranged at a position of the drum groove 42 is provided to the shift operation mechanism 4. The shifting cam mechanism 48 is set so that the sleeve dog 32 in the present shift stage is stroked to release the engaging dog teeth in the present shift stage before the dog teeth in the present shift stage move away from a drive tooth surface and come in contact with a coast tooth surface due to an occurrence of a differential rotation.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a seamless shift transmission mounted on a vehicle.

  Conventionally, when there is a shift request from the current gear to the next gear, a fastening stroke is given to the sleeve dog of the next gear among the sleeve dogs. When the engagement stroke of the sleeve dog of the next gear stage is completed, the dog teeth of the current gear stage are released by converting the differential rotation generated between the sleeve dog and the gear dog of the current gear stage into an axial force. Thus, a seamless shift transmission is known in which the driving force is not interrupted while using a dog clutch (see, for example, Patent Document 1).

JP 2012-127471 A

  In the conventional seamless shift type transmission, a differential rotation occurs between the gear dog and the sleeve dog of the current gear stage due to torque circulation from the next gear gear during a gear shift. Due to the occurrence of this differential rotation, there is a problem in that a collision sound is generated when the dog teeth of the current gear stage are separated from the drive tooth surface and contact the coast tooth surface.

  The present invention has been made paying attention to the above-mentioned problem. During a shift from the current shift speed to the next shift speed, the dog teeth of the current speed shift away from the drive tooth surface and contact the coast tooth surface due to the occurrence of differential rotation. It aims at preventing the collision sound which occurs by doing.

In order to achieve the above object, the present invention includes a plurality of speed change gear pairs, a dog clutch mechanism, a speed change operation mechanism, and a dog tooth removal cam mechanism.
The speed change operation mechanism is provided with a speed change cam mechanism which is a combination of a drum groove formed in the speed change drum and a bracket pin connected to a shift fork fitted to the sleeve dog and disposed at the position of the drum groove.
The shift cam mechanism strokes the sleeve dog of the current shift stage to stroke the dog dog of the current shift stage before the dog teeth of the current shift stage move away from the drive tooth surface and contact the coast tooth surface due to the occurrence of differential rotation. Set to release.

  In this way, the dog teeth of the current gear stage are pulled out before contacting the coast tooth surface, so that during the shift from the current gear stage to the next gear stage, the dog teeth of the current gear stage are driven by the occurrence of differential rotation. It is possible to prevent a collision sound generated by contacting the coast tooth surface away from the surface.

1 is an overall system diagram showing a drive system and a shift control system of an engine vehicle to which a seamless shift transmission of Example 1 is applied. FIG. 3 is a perspective view showing a driving state in which the drive tooth surface of the sleeve dog and the drive tooth surface of the gear dog are in contact with each other in the seamless shift transmission of the first embodiment. FIG. 3 is a perspective view showing a coast state in which a coast tooth surface of a sleeve dog and a coast tooth surface of a gear dog are in contact with each other in the seamless shift transmission of the first embodiment. FIG. 6 is a diagram illustrating a setting example of a circumferential relative position between a drum groove serving as a shift cam mechanism and a bracket pin in the seamless shift transmission according to the first embodiment. 6 is a flowchart illustrating a flow of a shift control process during a 1-2 upshift executed by a transmission controller of the seamless shift transmission according to the first embodiment. It is explanatory drawing which shows the torque circulation state which is the cause of the differential rotation which generate | occur | produces between the sleeve dog and gear dog of the present gear stage in the seamless shift type transmission of a comparative example. FIG. 5 is an explanatory diagram showing a positional relationship between a drum groove and a bracket pin at a low speed and a positional relationship between a drum groove and a bracket pin at a high speed in a seamless shift transmission of a comparative example. It is a collision sound generation effect explanatory drawing which shows the impact sound generation effect in the dog gear of the low speed stage in the seamless shift type transmission of a comparative example. It is explanatory drawing which shows the positional relationship change of a dog-tooth release cam mechanism when a collision sound generate | occur | produces in the seamless shift transmission of a comparative example. It is a time chart which shows each characteristic at the time of performing 1-> 2 shift in the seamless shift type transmission of a comparative example. In the seamless shift transmission of Example 1, it is explanatory drawing which shows the positional relationship of the drum groove and bracket pin in low speed stage, and the positional relationship of the drum groove and bracket pin in high speed stage. FIG. 3 is an explanatory diagram of a collision noise generation preventing action showing a collision noise generation preventing action at low-speed dog teeth in the seamless shift transmission of the first embodiment. It is explanatory drawing which shows the positional relationship change of a dog-tooth release cam mechanism when collision sound generation | occurrence | production is prevented in the seamless shift transmission of Example 1. FIG. 4 is a time chart showing characteristics when a 1 → 2 shift is executed in the seamless shift transmission of the first embodiment.

  Hereinafter, a mode for carrying out a seamless shift transmission according to the present invention will be described based on a first embodiment shown in the drawings.

  The seamless shift transmission A according to the first embodiment is a transmission that achieves three forward speeds, and is applied to an engine vehicle (an example of a vehicle) that includes an engine E as a driving source for traveling. Hereinafter, the configuration of the first embodiment will be described by being divided into “the overall system configuration”, “the configuration of the shift cam mechanism”, and “the shift control processing configuration”.

[Overall system configuration]
FIG. 1 shows a drive system and a shift control system of an engine vehicle to which the seamless shift transmission of the first embodiment is applied. The overall system configuration will be described with reference to FIG.

  As shown in FIG. 1, the seamless shift type transmission A includes a transmission gear train 2, a dog clutch mechanism 3, a transmission operation mechanism 4, and a dog tooth removal cam mechanism 5 in the case of the transmission case 1. ing. Outside the case of the transmission case 1, an engine E, a cam operating motor 6 (transmission actuator), and a transmission control device 7 (transmission control means) are provided.

  The transmission gear train 2 is provided on the input shaft 8 and the output shaft 9, and is a parallel two-shaft having a first gear pair 11in, 11out, a second gear pair 12in, 12out, and a third gear pair 13in, 13out that mesh with each other. Type gear train.

  An engine E is connected to one end of the input shaft 8 via a main clutch 10. On the axis of the input shaft 8, a first speed movable gear 11in, a second speed movable gear 12in, and a third speed movable gear 13in that are freely rotatable with respect to the input shaft 8 are provided.

  A first speed fixed gear 11out, a second speed fixed gear 12out, and a third speed fixed gear 13out are fixed on the output shaft 9 with respect to the output shaft 9.

  An output gear 21 is provided at one end of the output shaft 9. The output gear 21 meshes with the ring gear 23 of the differential gear 22 to constitute a final reduction gear pair. A drive shaft 24 is connected to each side gear of the differential gear 22. Left and right drive wheels 25 are attached to the respective ends of the drive shaft 24. Note that illustration and description of a reverse gear train having three gears meshing with each other are omitted.

  The dog clutch mechanism 3 is configured by a combination of a gear dog 31 and a sleeve dog 32. The gear dog 31 is provided on the movable gear (11in, 12in, 13in) of the speed change gear pair (first speed gear pair 11in, 11out, second speed gear pair 12in, 12out, third speed gear pair 13in, 13out). Have The sleeve dog 32 has a sleeve dog tooth 34 that meshes with the gear dog tooth 33 of the gear dog 31 (see FIGS. 2 and 3).

  The gear dog 31 includes a first speed gear dog 31a, a second speed gear dog 31b, and a third speed gear dog 31c. The first-speed gear dog 31a is fixed to a side surface position of the first-speed movable gear 11a that is not fixed to the shaft of the first-speed gear pair 11a, 11b, and has a first-speed gear dog tooth 33a. The second-speed gear dog 31b is fixed to the side surface position of the second-speed movable gear 12a that is not fixed to the shaft of the second-speed gear pair 12a, 12b, and has second-speed gear dog teeth 33b. The third-speed gear dog 31c is fixed to a side surface position of the third-speed movable gear 13a that is not fixed to the shaft of the third-speed gear pair 13a, 13b, and has a third-speed gear dog tooth 33c.

  The sleeve dog 32 includes a first speed sleeve dog 32a, a second speed sleeve dog 32b, and a third speed sleeve dog 32c. The first speed sleeve dog 32a is disposed adjacent to the first speed gear dog 31a and has sleeve dog teeth 34a that mesh with the first speed gear dog teeth 33a. The second speed sleeve dog 32b is disposed adjacent to the second speed gear dog 31b, and has sleeve dog teeth 34b that mesh with the second speed gear dog teeth 33b. The third speed sleeve dog 32c is disposed adjacent to the third speed gear dog 31c, and has sleeve dog teeth 34c that mesh with the third speed gear dog teeth 33c.

  The shift operation mechanism 4 is connected to the sleeve dog 32 and has a function of giving a fastening stroke to the sleeve dog 32 of the next shift stage when there is a shift request from the current shift stage to the next shift stage.

  The speed change operation mechanism 4 includes a speed change drum 41, a drum groove 42, a shift arm 43, a shift rod 44, a shift fork 45, a bracket pin 46, a check ball 47, and a speed change cam mechanism 48. . The speed change cam mechanism 48 is configured by a combination of the drum groove 42 and the bracket pin 46, and converts the rotational motion of the speed change drum 41 into the stroke motion of the shift fork 45.

  The speed change drum 41 is a cylindrical drum that is rotated by a single cam operating motor 6 about the drum central axis as a rotation axis. The speed change drum 41 has a first speed drum groove 42a, a second speed drum groove 42b, and a third speed drum groove 42c formed on the circumference. Each of the first speed drum groove 42a, the second speed drum groove 42b, and the third speed drum groove 42c has a shape that realizes a desired stroke operation of the shift fork 45 in each speed change pattern in which the speed change drum 41 rotates.

  The shift arm 43 includes a first speed shift arm 43a, a second speed shift arm 43b, and a third speed shift arm 43c. A first speed bracket pin 46a disposed at the position of the first speed drum groove 42a is provided at one end of the first speed shift arm 43a, and the other end is fixed to a first speed shift rod 44a described later. A two-speed bracket pin 46b disposed at the position of the second-speed drum groove 42b is provided at one end of the second-speed shift arm 43b, and the other end is fixed to a second-speed shift rod 44b described later. One end of the third speed shift arm 43c is provided with a third speed bracket pin 46c disposed at the position of the third speed drum groove 42c, and the other end is fixed to a third speed shift rod 44c described later.

  The shift rod 44 is disposed in parallel with the input shaft 8 and the output shaft 9, and includes a first speed shift rod 44a, a second speed shift rod 44b, and a third speed shift rod 44c provided to be movable in the axial direction. The first-speed shift rod 44a is provided with a first-speed check ball 47a that regulates an axial stroke amount of the first-speed shift rod 44a by pressing a spring-biased ball into a groove formed in the rod shaft. The 2-speed shift rod 44b is provided with a 2-speed check ball 47b similar to the 1-speed check ball 47a. The third speed shift rod 44c is provided with a third speed check ball 47c similar to the first speed check ball 47a.

  The shift fork 45 includes a first speed shift fork 45a, a second speed shift fork 45b, and a third speed shift fork 45c. One end of the first speed shift fork 45a is fixed to the first speed shift rod 44a, and the other end is fitted to the first speed sleeve dog 32a. One end of the 2-speed shift fork 45b is fixed to the 2-speed shift rod 44b, and the other end is fitted to the 2-speed sleeve dog 32b. One end of the third speed shift fork 45c is fixed to the third speed shift rod 44c, and the other end is fitted to the third speed sleeve dog 32c.

  The dog tooth removal cam mechanism 5 includes an input shaft provided with a sleeve dog 32 (first speed sleeve dog 32a, second speed sleeve dog 32b, third speed sleeve dog 32c), a first speed movable gear 11in, a second speed movable gear 12in, and a third speed movable gear 13in. 8 is provided. This dog tooth removal cam mechanism 5 converts the differential rotation generated between the sleeve dog 32 and the gear dog 31 of the current gear stage by the engagement of the dog gear of the next gear stage to the axial force to convert the dog dog teeth of the current gear stage. Has the function of releasing Furthermore, in a dog tooth fastening state, it has a function which connects and fixes movable gear 11in, 12in, 13in with respect to the input shaft 8 so that torque transmission is possible.

  The dog tooth removal cam mechanism 5 includes a cam groove 51 formed in a hub 53 provided integrally with the input shaft 8, and a sleeve pin 52 that protrudes toward the inside of the cam groove 51. (See FIGS. 2 and 3).

  The cam groove 51 includes a first speed cam groove 51a, a second speed cam groove 51b, and a third speed cam groove 51c. The first-speed cam groove 51a is a V-shaped groove formed by engraving on the cylindrical peripheral surface of a first-speed hub 53a that is fixed to or integrated with the input shaft 8. The second-speed cam groove 51b is a V-shaped groove formed by carving into the cylindrical peripheral surface of a second-speed hub 53b that is fixed to or integrated with the input shaft 8. The third-speed cam groove 51c is a V-shaped groove formed by carving into the cylindrical peripheral surface of a third-speed hub 53c that is fixed to or integrally with the input shaft 8.

  The sleeve pin 52 includes a first speed sleeve pin 52a, a second speed sleeve pin 52b, and a third speed sleeve pin 52c. The first-speed sleeve pin 52a is a cylindrical pin that is provided so as to protrude in the inner diameter direction from the inner surface of the first-speed sleeve dog 32a. The 2nd speed sleeve pin 52b is a cylindrical pin provided so as to protrude from the inner surface of the 2nd speed sleeve dog 32b in the inner diameter direction. The 3rd speed sleeve pin 52c is a cylindrical pin provided so as to protrude from the inner surface of the 3rd speed sleeve dog 32c in the inner diameter direction.

  The shift control device 7 includes a transmission controller 71 that controls a rotation angle and a rotation direction of the shift drum 41 by a current command to the cam operating motor 6 when a shift request is made. Note that the rotation angle range and the rotation direction of the shift drum 41 are determined in advance for each shift pattern.

  The transmission controller 71 inputs information from the vehicle speed sensor 72, the accelerator opening sensor 73, the first speed sleeve stroke sensor 74, the second speed sleeve stroke sensor 75, and the third speed sleeve stroke sensor 76. Further, information from the engine rotation sensor 77, the input shaft rotation sensor 78, the inhibitor switch 79, the encoder 80, etc. is input.

  The transmission controller 71 executes shift control using a well-known shift schedule in which each shift speed region is set on a two-dimensional coordinate plane based on the vehicle speed VSP and the accelerator opening APO. That is, when the operating point (VSP, APO) on the shift schedule crosses the upshift line or the downshift line, a shift command for fastening the sleeve dog 32 of the next shift stage is output.

[Configuration of shifting cam mechanism]
FIG. 2 shows a drive state in which the drive tooth surface of the sleeve dog tooth 34 and the drive tooth surface of the gear dog tooth 33 are in contact (the surface where the sleeve dog tooth 34 and the gear dog tooth 33 are in contact with each other in the drive state is the drive tooth surface). ). FIG. 3 shows a coast state in which the coast tooth surface of the sleeve dog tooth 34 and the coast tooth surface of the gear dog tooth 33 are in contact (the surface where the sleeve dog tooth 34 and the gear dog tooth 33 contact each other in the coast state is referred to as a coast tooth surface). ). FIG. 4 shows an example of setting the relative position in the circumferential direction between the drum groove 42 and the bracket pin 46. Hereinafter, the configuration of the shifting cam mechanism 48 will be described with reference to FIGS.

  Before the dog gear of the current gear stage moves away from the drive tooth surface and contacts the coast tooth surface due to the occurrence of differential rotation, the speed change cam mechanism 48 is caused to stroke the sleeve dog 32 of the current gear step to engage the dog of the current gear step. It is set to release teeth. By adopting this speed change cam mechanism 48, the collision noise caused by the coast tooth contact is prevented.

  That is, when the speed change drum 41 is rotated at the time of speed change, until the differential rotation occurs between the sleeve dog 32 and the gear dog 31, the sleeve dog teeth 34 and the gear dog teeth 33 of the current gear stage are shown in FIG. This is a drive state in which the drive tooth surfaces are in contact with each other. However, if the shift cam mechanism 48 is not employed, the sleeve dog teeth 34 and the gear dog teeth 33 at the current shift stage are separated from the contact between the drive tooth surfaces due to the occurrence of differential rotation, and as shown in FIG. The coast tooth surfaces of the gear dog teeth 33 come into contact with each other.

  On the other hand, when the timing for reaching the dog tooth fastening start point is reached on the second gear stage, not the timing at which the dog gear fastening stroke is completed on the second gear stage, the gear shift that starts releasing the dog teeth on the current gear stage. The cam mechanism 48 is set.

  That is, a case where the low speed stage is set to the first speed stage, the high speed stage is set to the second speed stage, and the shifting drum 41 is rotated upward in FIG. At this time, when the circumferential relative positions of the second speed drum groove 42b and the second speed bracket pin 46b in the second speed stage are in the positions shown in the right part of FIG. 4, the first speed drum groove 42a and the first speed in the first speed stage The relative position in the circumferential direction of the bracket pin 46a is set to a relationship shown in the left part of FIG. That is, the shift cam mechanism 48 is set to start dog tooth release on the first gear side at the timing when the dog gear engagement is started on the second gear side. At this time, the shifting cam mechanism 48 does not change the shape of the first-speed drum groove 42a, and the position of the circumferential direction of the first-speed bracket pin 46a relative to the first-speed drum groove 42a is changed from the position indicated by the broken line in FIG. This is realized by changing and setting the position indicated by.

[Shift control processing configuration]
An example is shift control in which the low speed stage is set to the first speed stage, the high speed stage is set to the second speed stage, and the shifting drum 41 is rotated upward in FIG. FIG. 5 shows the flow of the shift control process at the time of 1-2 upshift executed by the transmission controller 71. Hereinafter, the shift control processing configuration at the time of 1-2 upshift will be described based on FIG.

  In step S1, it is determined whether or not there is a 1-2 upshift request. If it is determined in step S1 that there is a 1-2 upshift request, the process proceeds from step S1 to step S2 to step S3. Then, while it is determined in step S3 that the first gear dog tooth release stroke has not been completed, the flow from step S2 to step S3 is repeated.

  That is, in step S2, by outputting an energization current to the cam operating motor 6, the speed change drum 41 rotates, and a dog tooth fastening stroke is given to the second speed sleeve dog 32b. Further, the dog-tooth release stroke is given to the first-speed sleeve dog 32 a by the rotation of the transmission drum 41.

  Thereafter, when it is determined in step S3 that the first gear dog tooth release stroke has been completed, the process proceeds from step S3 to step S4 to the end. In step S4, the energization current output to the cam operating motor 6 is output. Is set to zero and the 1-2 upshift control is terminated. Here, the completion of the first gear dog tooth release stroke is determined by indicating the value at which the sensor value from the first gear sleeve stroke sensor 74 has reached the complete release stroke position.

  Next, the operation of the first embodiment will be described by being divided into “shift control operation in the comparative example” and “shift control operation in the first embodiment”.

[Shift control action in comparative example]
Hereinafter, the shift control operation in the comparative example will be described with reference to FIGS.
First, in order to achieve a seamless shift without running out of torque, the seamless shift type transmission is engaged without releasing the low-speed dog clutch when engaging the high-speed dog clutch during upshifting from the low-speed gear to the high-speed gear. Will be left.

  Therefore, at the time of shifting, as shown in FIG. 6, when the high speed gear dog and the sleeve dog start to engage the dog teeth, and the torque flow is generated in the high speed stage path, the low speed gear dog and the sleeve dog are engaged. Maintaining it generates circulating torque. This torque circulation causes differential rotation between the low-speed gear dog and the sleeve dog. In other words, by utilizing the fact that differential rotation occurs between the gear dog and the sleeve dog at the low speed stage, the dog gear cam mechanism that converts the differential rotational force into an axial force (thrust force) while allowing the differential rotation is used. The seamless shift transmission is designed to release the dog clutch.

  Here, when the upshift from the low speed stage to the high speed stage is performed, a seamless shift transmission that starts the release stroke of the low speed stage dog clutch after the engagement stroke of the high speed stage dog clutch is completed is used as a comparative example.

  In the case of this comparative example, when the shift drum is rotated upward in FIG. 7 and an upshift is performed from the low speed stage to the high speed stage, the low speed is the timing at which the speed change starts from the dog tooth engagement start point on the high speed stage side. On the step side, the dog teeth are not released. That is, as shown in FIG. 7, the low-speed bracket pin is not in contact with the drum groove.

  Until the dog tooth fastening start point is reached on the high speed side, the gear dog and the sleeve dog on the low speed stage side are in contact with the drive tooth surfaces of the gear dog and the sleeve dog tooth as shown in the right part of FIG. However, when the dog teeth start meshing from the dog tooth fastening start point on the high speed stage side, torque circulation starts, and differential rotation occurs between the low speed gear dog and the sleeve dog as shown in the left part of FIG. Due to the occurrence of this differential rotation, the relative positions of the low-speed gear dog and the sleeve dog are displaced, and the gear dog tooth and the sleeve dog tooth are separated from the contact state of the drive tooth surface and contact the coast tooth surface to generate a collision sound.

  Then, the sleeve dog starts to be pushed by the coast tooth surface of the gear dog on the low speed stage side, and as shown in FIG. 9, the dog tooth release cam mechanism 5 has the sleeve pin interlocked with the sleeve dog first facing the cam groove in the circumferential direction. Move. Thereafter, the sleeve pin moves to the neutral position along the slope of the cam groove.

The 1-2 upshift control action in the comparative example will be described with reference to FIG.
In FIG. 10, time t1 is a 1-2 upshift control start time, an energizing current is applied to the actuator, and the drum rotation angle of the shifting drum starts to increase. Time t2 is an increase start time of the engine speed / input speed. Time t3 is the fastening stroke start time of the second speed sleeve dog. Time t4 is the arrival time of the 2nd speed sleeve dog to the complete fastening stroke and the release stroke start time of the 1st speed sleeve dog. Time t5 is the release stroke end time of the first-speed sleeve dog and the time when the actuator current is made zero. Time t6 is the time when the engine speed / input speed returns to the speed at time t4.

  In this way, when the second-speed dog teeth are completely engaged at time t4, the first-speed dog teeth are released. For this reason, in the case of a comparative example, there exists a subject that a gear dog tooth and a sleeve dog tooth will contact a coast tooth surface from the contact state of a drive tooth surface, and a collision noise will generate | occur | produce.

[Shift Control Action in Embodiment 1]
The first embodiment is made by paying attention to the above problem. When the speed change drum 41 rotates, the low speed stage side dog dog is stroked before the low speed stage dog tooth contacts the coast tooth surface. A shifting cam mechanism 48 for pulling out teeth is employed. Hereinafter, the shift control operation in the first embodiment will be described with reference to FIGS.

  In the case of the first embodiment, when the shift drum 41 is rotated upward in FIG. 11 to perform an upshift from the low speed stage (first speed stage) to the high speed stage (second speed stage), the dog teeth on the second speed stage side. Dog tooth release is started on the first gear side at the timing of starting the fastening. That is, as shown in FIG. 11, the first-speed bracket pin 46a contacts the first-speed drum groove 42a.

  Until the dog tooth fastening start point is reached on the second speed stage, the first speed gear dog 31a and the first speed sleeve dog 32a on the first speed stage side, as shown in the right part of FIG. The drive tooth surfaces of the sleeve dog teeth 34a are in contact with each other. However, when the dog teeth start meshing from the dog tooth fastening start point on the second gear stage, torque circulation starts, and differential rotation occurs between the first gear dog 31a and the first gear sleeve 32a as shown in the left part of FIG. . Due to this differential rotation, the relative positions of the first speed gear dog 31a and the first speed sleeve dog 32a are displaced, and the first speed gear dog teeth 33a and the first speed sleeve dog teeth 34a are separated from the contact state of the drive tooth surface.

  However, when the speed change drum 41 is rotated, the speed change cam mechanism 48 is employed in which the low speed stage side dog teeth are stroked to remove the low speed stage side dog teeth before the low speed stage side dog teeth contact the coast tooth surface. Therefore, before the first-speed gear dog teeth 33a and the first-speed sleeve dog teeth 34a come into contact with the coast tooth surface by the shift cam mechanism 48, the first-speed gear dog teeth 33a are removed from the first-speed gear dog teeth 33a. In other words, the dog tooth release timing of the first speed gear dog 31a and the first speed sleeve dog 32a is made earlier than in the comparative example, thereby avoiding the contact between the coast tooth surfaces of the first speed gear dog teeth 33a and the first speed sleeve dog teeth 34a. .

  For this reason, the 1st-speed sleeve dog 32a is not pushed by the coast tooth surface of the 1st-speed gear dog tooth 33a. For this reason, in the dog tooth removal cam mechanism 5, as shown in FIG. 13, the first speed sleeve pin 52a interlocked with the first speed sleeve dog 32a is linear along the first speed cam groove 51a formed in the first speed tooth portion 53a. Move to the neutral position.

The 1-2 upshift control action in the first embodiment will be described with reference to FIG.
In FIG. 14, a time t1 is a 1-2 upshift control start time, an energizing current is applied to the actuator, and the drum rotation angle of the speed change drum 41 starts to rise. Time t2 is an increase start time of the engine speed / input speed. Time t3 is the fastening stroke start time of the second speed sleeve dog. Time t4 is the arrival time of the second speed sleeve dog 32b to the fastening point and the release stroke start time of the first speed sleeve dog 32a. Time t5 is the time for completing the fastening stroke of the second-speed sleeve dog 32b. Time t6 is the release stroke end time of the first-speed sleeve dog 32a and the time when the actuator current is made zero. Time t7 is the time at which the engine speed / input speed returns to the speed at time t5.

  As described above, when the second speed gear dog teeth 33b and the second speed sleeve dog teeth 34b reach the fastening point at time t4, the first speed sleeve dog 32a is stroked to start releasing the first speed dog teeth. As a result, the section from time t4 to time t5 is the section in which the high speed stage engagement stroke and the low speed stage release stroke overlap. The shift gear mechanism 48 advances the release stroke of the first-speed sleeve dog 32a before the high-speed stage engagement stroke is completed, so that the coast tooth surfaces of the first-speed gear dog teeth 33a and the first-speed sleeve dog teeth 34a To avoid contact. For this reason, in the case of Example 1, the 1st-speed gear dog tooth 33a and the 1st-speed sleeve dog tooth 34a can prevent the collision sound which arises when it leaves | separates from the contact state of a drive tooth surface, and contacts a coast tooth surface.

  As described above, the seamless shift transmission A according to the first embodiment has the following effects.

(1) A plurality of speed change gear pairs (first speed gear pair 11in, 11out, second speed gear pair 12in, 12out, third speed gear pair 13in, 13out) provided on the input shaft 8 and the output shaft 9 and meshing with each other, and a dog clutch mechanism 3, a speed change operation mechanism 4, and a dog tooth removal cam mechanism 5.
The dog clutch mechanism 3 is provided on the movable gears 11in, 12in, and 13in of the transmission gear pair, and is a combination of a gear dog 31 having a gear dog tooth 33 and a sleeve dog 32 having a sleeve dog tooth 34 meshing with the gear dog tooth 33 of the gear dog 31. .
The shift operation mechanism 4 is connected to the sleeve dog 32, and gives a fastening stroke to the sleeve dog 32 of the next shift stage when there is a shift request from the current shift stage to the next shift stage.
The dog tooth removal cam mechanism 5 is provided between the sleeve dog 32 and the movable gear shaft (input shaft 8), and is differentially generated between the sleeve dog 32 and the gear dog 31 of the current gear stage when the dog gear of the next gear stage is fastened. Is converted into an axial force to release the engagement dog teeth of the current gear.
Shifting by a combination of a drum groove 42 formed on the speed change drum 41 and a shift fork 45 fitted to the sleeve dog 32 and a bracket pin 46 disposed at the position of the drum groove 42 is connected to the speed change operation mechanism 4. Cam mechanism 48 is provided.
The shift cam mechanism 48 strokes the sleeve dog 32 of the current shift stage before the dog teeth of the current shift stage separate from the drive tooth surface and contacts the coast tooth surface due to the occurrence of the differential rotation, thereby engaging the engagement dog of the current shift stage. Set to release teeth.
In this way, the dog teeth of the current gear stage are pulled out before contacting the coast tooth surface, so that during the shift from the current gear stage to the next gear stage, the dog teeth of the current gear stage are driven by the occurrence of differential rotation. It is possible to prevent a collision sound generated by contacting the coast tooth surface away from the surface.
In addition, by suppressing the dog tooth collision, the durability reliability of the gear dog 31 having the gear dog teeth 33 and the sleeve dog 32 having the sleeve dog teeth 34 can be improved.

(2) When the shift drum 41 rotates during the shift, the relative position of the shift cam mechanism 48 in the circumferential direction is reached when the engagement stroke of the sleeve dog 32 of the next shift stage reaches the dog tooth engagement start point before the completion of the engagement stroke. Then, the setting is made so as to start releasing the dog teeth at the current gear stage.
Thus, by setting the shift cam mechanism 48 that starts releasing the dog teeth at the current shift stage when the dog gear engagement start point at the next shift stage is reached, the coasting tooth surface is brought into contact with the rotation of the shift drum 41. The fastening dog teeth of the current gear stage can be released before starting.
Here, the release of the fastening dog teeth does not mean release until the complete release stroke, but may be a release stroke that avoids at least contact with the coast tooth surface.

(3) A speed change actuator is provided for rotating the speed change drum 41 during speed change.
The speed change actuator is a single cam operating motor 6 that strokes all of the sleeve dogs 32 for each speed step according to the rotational angle position of the speed change drum 41.
Thus, by using one cam operating motor 6 that rotates the speed change drum 41 as a speed change actuator, it is possible to provide a seamless shift type transmission A that is advantageous in terms of cost and space.

  The seamless shift transmission of the present invention has been described based on the first embodiment. However, the specific configuration is not limited to the first embodiment, and design changes and additions are permitted without departing from the gist of the invention according to each claim of the claims.

  In the first embodiment, the shift operation according to the 1-2 upshift example is shown as the shift pattern. However, the shift pattern may be an example of an upshift other than the 1-2 upshift. Furthermore, in the case of a downshift, the differential dog is disengaged by converting the differential rotation into an axial force, so that various downshift pattern examples may be used.

  In the first embodiment, when setting the circumferential relative position of the shifting cam mechanism by the drum groove 42 and the bracket pin 46 as the speed change operation mechanism 4, the drum groove 42 is not changed and the circumferential position of the bracket pin 46 is changed. An example of setting is shown. However, the shift operation mechanism may be an example in which when setting the circumferential relative position of the shift cam mechanism, the drum groove shape is changed and the circumferential position of the bracket pin is not changed. Moreover, it is good also as an example which performs and changes both the shape change of a drum groove, and the circumferential direction position change of a bracket pin.

  In the first embodiment, an example in which the cam actuator motor 6 is configured to stroke all the sleeve dogs 32 for each gear position according to the rotational angle position of the speed change drum 41 is shown as the speed change actuator. However, the speed change actuator may be an example in which each sleeve dog is moved by a separate motor. Further, as the speed change actuator, a plurality of sleeve dogs may be divided into, for example, an upshift pattern and a downshift pattern, and may be moved by a separate motor for each speed change pattern.

  In the first embodiment, as an example of the seamless shift transmission according to the present invention, a transmission having three forward speeds is shown. However, the number of forward gears and reverse gears is not limited to that of the first embodiment, and may of course be an example of a transmission having four or more forward gears.

  In Example 1, the example which applies the seamless shift type transmission of this invention to an engine vehicle was shown. However, the seamless shift transmission of the present invention can also be applied to other vehicles such as hybrid vehicles and electric vehicles.

A seamless shift transmission E engine 1 transmission case 2 transmission gear train 11in, 11out first speed gear pair 12in, 12out second speed gear pair 13in, 13out third speed gear pair 3 dog clutch mechanism 31 gear dog 32 sleeve dog 33 gear dog teeth 34 sleeve dog teeth 4 Shifting operation mechanism 41 Shifting drum 42 Drum groove 45 Shift fork 46 Bracket pin 48 Shifting cam mechanism 5 Dog tooth removal cam mechanism 51 Cam groove 52 Sleeve pin 53 Hub 6 Cam operating motor (shifting actuator)
7 Transmission control device 71 Transmission controller 8 Input shaft (movable gear shaft)
9 Output shaft

Claims (3)

A plurality of transmission gear pairs provided on the input shaft and the output shaft and meshing with each other;
A dog clutch mechanism which is provided on a movable gear of the transmission gear pair and is a combination of a gear dog having a gear dog tooth and a sleeve dog tooth engaging a gear dog tooth of the gear dog;
A shift operation mechanism that is connected to the sleeve dog and that gives a fastening stroke to the sleeve dog of the next shift stage when there is a shift request from the current shift stage to the next shift stage;
Fastening of the current gear stage by converting the differential rotation generated between the sleeve dog and gear dog of the current gear stage to the axial force, which is provided between the sleeve dog and the movable gear shaft, and the dog teeth of the next gear stage are fastened. A dog tooth release cam mechanism for releasing the dog teeth,
The speed change operation mechanism is provided with a speed change cam mechanism which is a combination of a drum groove formed in the speed change drum and a bracket pin connected to a shift fork fitted to the sleeve dog and disposed at the position of the drum groove. ,
The shift cam mechanism is configured to stroke the sleeve dog of the current shift stage before the dog teeth of the current shift stage come away from the drive tooth surface and contact the coast tooth surface due to the occurrence of differential rotation. A seamless shift transmission characterized in that it is set to release. The seamless shift transmission according to claim 1,
When the shifting drum rotates during shifting, the relative position of the shifting cam mechanism in the circumferential direction reaches the dog tooth engagement starting point when the sleeve dog engagement stroke of the next shifting stage reaches the dog tooth engagement start point. A seamless shift transmission characterized by setting to start. The seamless shift transmission according to claim 1 or 2,
Providing a speed change actuator for rotating the speed change drum during speed change;
The seamless shift transmission, wherein the shift actuator is a single cam operating motor that strokes all of the sleeve dogs for each shift stage in accordance with the rotational angle position of the shift drum.