JPH0599333A - Normally meshing transmission - Google Patents

Abstract

PURPOSE:To provide a normally meshing transmission wherein a shift gate is arranged so that a moving distance of a speed change shifter is shortened as short as possible and further averaged at the time of speed change. CONSTITUTION:In a normally meshing transmission 10, a plurality of usually meshing speed change gear trains (51 to 56 and 61 to 66) are arraned between a main shaft 13 and a countershaft 14 to mount a plurality of dog tooth clutches 71, 72, 74, having sleeves 71s, 72s, 74s movable so as to engage/disengage with/ from dog teeth mounted respectively to the adjacent speed change gear trains, onto a main shaft 13. Two synchronizing means 121, 126 are provided in the dog tooth clutch 71 for the lowest and highest speed change shifts of a plurality of the speed change gear trains. A shift gate 101 for a synchronous shift connected to a sleeve of the dog tooth clutch 71 for the lowest and highest speed change shifts is arranged in the intermediate of the other shift gates 102, 104.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called constant mesh type transmission used in a vehicle, and more particularly to one in which automatic shift control is performed.

[0002]

2. Description of the Related Art A constant mesh transmission includes a plurality of constant mesh gear trains arranged between a main shaft (connected / disconnected from an input shaft by a clutch) and a counter shaft. Has been. Also, on the main shaft or the counter shaft, it moves so as to engage and disengage the dog teeth attached to the adjacent gear train for shifting (actually, either the gear on the main shaft side or the gear on the counter shaft side). A plurality of dog tooth clutches having a free sleeve are also provided. When the sleeve engages with the dog tooth, the rotation of the main shaft is transmitted to the counter shaft via the gear train for speed change to which the dog tooth is attached. Such a constant mesh transmission can be used as an automatic transmission by including a shift shifter driven by a drive motor or the like (shifter driving means) that operates based on a shift command from a computer or the like. Many. The shift shifter selectively pushes one of the shift gates connected to the sleeves of the dog tooth clutches to move the sleeve connected to the shift gates. Note that all shift gates are arranged as a group (shift gate group). The shift shifter moves in a direction (hereinafter, referred to as a select direction) for selecting a shift gate to be pushed in the shift gate group (select movement) and a direction for pushing the selected shift gate (hereinafter, referred to as a shift direction). The movement (referred to as the shift direction) is performed (shift movement).

Further, in such a transmission, for example,
There is a device provided with a synchronizing device as disclosed in JP-B-54-28894. In this structure, a synchronizing gear train is attached to the ends of the main shaft and the counter shaft, separately from the above-mentioned gear train for shifting. Then, by accelerating or braking the rotation of the synchronizing gear train on the counter shaft side when shifting to each shift stage,
The rotation of the main shaft is accelerated and decelerated so that the rotation of the dog tooth clutch (sleeve) mounted on the main shaft is synchronized with the rotation of the dog tooth with which it should engage.

However, in such a synchronizing device, since a synchronizing gear train and other synchronizing clutch means are provided separately from the shifting gear train, there is a problem that the weight of the transmission increases. Therefore, in order to solve such a problem, a synchronizing means, that is, a transmission provided with a synchromesh mechanism only in the dog tooth clutches for the lowest gear and the highest gear (hereinafter, for the sake of convenience, the lowest / highest gear synchronous type). Gearbox) is being considered. With this gear, gears other than the lowest and highest gears (hereinafter referred to as intermediate gears)
In the shifting process to, the shift gate temporarily pushes the shift gate (hereinafter referred to as the synchronous shift gate) that is connected to the sleeve of the dog tooth clutch (hereinafter referred to as the synchronized dog tooth clutch) equipped with the synchromesh mechanism. Then, the sleeve for the synchronization stage is moved to the synchronization position where the synchromesh mechanism acts. By the action of the synchromesh mechanism, the speed of rotation of the main shaft is increased / decreased, that is, the rotation of the sleeve and the dog tooth in the dog tooth clutch for the intermediate shift stage at the gear shift destination is synchronized. More specifically, when shifting from a low gear to a high gear, the synchromesh mechanism on the highest gear side acts to decelerate the main shaft. On the other hand, at the time of shifting from the high gear to the low gear, the synchromesh mechanism on the lowest gear side acts to accelerate the main shaft.
As a result, it is possible to perform rotation synchronization at the time of shifting to all shift stages without providing a gear train other than the gear train for shifting. After the rotation is synchronized in this way, the shift shifter engages the sleeve for the target shift speed with the dog teeth to complete the shift.

However, in the shift gate arrangement in the lowest / highest stage synchronous transmission proposed in Japanese Patent Laid-Open No. 61-92343, for example, the shift gate arrangement shown in FIG. 10 is used. That is, the shift gates I and VI for the synchronous gears connected to the sleeves of the dog dog clutch with synchro (the dog gear clutch for the lowest gear (first gear) and the highest gear (the sixth gear)) are the gear trains for each gear. According to the arrangement in the transmission (arranged in order from the first speed gear train to the sixth speed gear train), the shift gates are arranged at the left end and the right end.

In a transmission having such a shift gate arrangement, for example, when shifting from the first speed to the second speed,
As shown by a dotted line a in the figure, the shift shifter first shifts from a position (hereinafter, simply referred to as “up”) at which the shift gate I for the synchronous stage arranged at the left end of the shift gate group can be pushed. Select movement is performed on the shift gate VI for the synchronization stage arranged at the right end of the gate group. Then, the shift gate VI for the synchronization stage is slightly moved, that is, the sleeve is shifted so as to move to the synchronization position. afterwards,
The selected gate is again moved onto the shift gate II arranged at the left end of the shift gate group, and the shift gate II is pushed and pushed so that the sleeve connected thereto is located at the engagement position.

[0007]

However, when shifting from such a minimum / maximum shift stage to an intermediate shift stage, there is a problem that the shift distance of the shift shifter in the select direction becomes considerably long. In particular, from the lowest (first speed) / highest shift speed (sixth speed) to immediately above (second speed).
When shifting to the intermediate gear position immediately below (5th speed), the shift shifter has to select the distance corresponding to the reciprocating distance between one end and the other end of the shift gate group. This may lead to delay in shift control. On the other hand, for example, as indicated by a chain line b in FIG. 6, the shift distance of the shift shifter in the select direction during the shift between the fourth speed and the fifth speed is one quarter of the shift time.
The degree is sufficient (the same applies to shifting from the third speed to the second speed). This causes a large difference in the moving distance between both gear shifts, that is, the gear shift time, and impairs the smoothness in continuously performing gear shift control during acceleration / deceleration of the vehicle.

The present invention has been made in view of the above problems, and provides a constant mesh type transmission in which the moving distance of the shift shifter during shifting can be minimized and averaged. The purpose is to

[0009]

To achieve the above object, in the constant mesh transmission of the present invention, the shift gate for the synchronous stage is arranged in the middle of the other shift gates. An automatic positioning mechanism may be provided so that when the shifter driving means is in the inoperative state, the shift shifter may be returned to the synchronous shift gate for positioning.

[0010]

In the constant mesh type transmission in which the shift gate is arranged in this way, the shift distance of the shift shifter is maximum,
The distance from above the shift gate of the current shift stage located at the end of the shift gate group to above the shift gate for the synchronous stage located in the middle of the shift gate group, and from there the target located at the end of the shift gate group The distance to the shift gate of the shift stage, that is, the distance from one end to the other end of the shift gate group is sufficient. In this way, the maximum shift distance of the shift shifter in the select direction is shortened, so that the shift time is averaged. Moreover, if an automatic positioning mechanism is provided,
When the shifter for shifting is not driven by the shifter drive means, it is automatically returned to the shift gate for the synchronous stage, so that it is not necessary to control the return, so the operation control of the shifter drive means is simplified. be able to.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a constant mesh transmission 10 according to the present invention. In addition, this transmission 10
Is attached to the engine E as shown in FIG. 11, and has an input shaft 12 which is connected to an output shaft (not shown) of the engine E and rotates. A main clutch 20 is attached to the right of the input shaft 12. The main clutch 20 includes a flyhole 21 integrally attached to the right end of the input shaft 12, and a pressure plate 2 arranged at a position facing the right end surface of the flyhole 21.
2 and. A clutch plate 23 is arranged between the fly hole 21 and the pressure plate 22 so as to be sandwiched therebetween. The clutch plate 23 is rotatably supported to the right of the input shaft 12 (however, the main shaft 13 is rotatable independently of the input shaft 12).
It is attached to the left end of the. In addition, facing surfaces (friction plates) 23 are provided on both left and right end surfaces of the clutch plate 23.
a and 23a are attached.

A diaphragm spring 25 is arranged on the right side of the pressure plate 22. The diaphragm spring 25 is supported by a clutch cover 26 extending from the right end of the flyhole 21 so as to cover the pressure plate 22. Further, on the right side of the central portion of the diaphragm spring 25, the main shaft 1
A release bearing 27 is arranged so as to surround 3. The release bearing 27 swings to the left and right of a release fork 28 extending upward from the right side thereof (a swing fulcrum 29 arranged at an intermediate portion in the up-down direction of the release fork 28).
Is performed centered on), it is moved in the left-right direction.

The left and right swing of the release fork 28 is performed by operating the clutch motor 31 mounted above the release fork 28 and pulling the release release spring 35 mounted between the upper left end of the case 11 and the upper part of the release fork 28. It is done by using power and force. That is, the ball screw shaft 32 is connected to the rotating shaft of the clutch motor 31. Then, the ball screw housing 33 moving to the right on the ball screw shaft 32 rotated by the operation of the motor 31 pushes the upper end portion of the release fork 28 to the right, so that the fulcrum 2 on the release fork 28 is reached.
The lower end side of 9 is moved to the left. Further, the upper portion of the release fork 28 thus swung is pulled by the release releasing spring 35 and returns to the left (at this time, the ball screw housing 33 is also returned to the left while rotating the ball screw shaft 32), so that the release fork is released. The lower end of 28 is moved to the right.

The main clutch 20 constructed in this way
Then, when the clutch motor 31 is not operated, the pressure plate 22 is pressed leftward by the diaphragm spring 25, and the clutch plate 23 is sandwiched between the pressure plate 22 and the fly hole 21. As a result, the flyhole 21 and the clutch plate 23 are coupled by the strong frictional force generated on the surface of the facing 23a, and the rotation of the flyhole 21 (that is, the rotation of the input shaft 12) is changed to the clutch plate 23 (that is, the main shaft). 13). On the other hand, when the clutch motor 31 operates, the release fork 28 moves the release bearing 27 to the left. The release bearing 27 abuts near the central portion of the diaphragm spring 25 and pushes it in the left direction, and the leftward pressing of the pressure plate 22 by the diaphragm spring 25 is released. As a result, the fly hole 21 and the clutch plate 23 are disconnected from each other, and the rotation of the fly hole 21 is not transmitted to the clutch plate 23.

As shown in FIG. 1, on the main shaft 13, the third speed drive gear 53 and the second speed drive gear 5 are arranged from the left.
A second speed drive gear 56, a first speed drive gear 51, a fifth speed drive gear 55 and a fourth speed drive gear 54 are provided. The drive gears 51 to 56 are connected to the main shaft 13
It is attached rotatably with respect to.

Below the main shaft 13, a counter shaft 14 extending in parallel therewith is rotatably supported. On the counter shaft 14, from the left, the final drive gear 41, the third-speed driven gear 63, and the second
A fast driven gear 62, a sixth driven gear 66, a first driven gear 61, a fifth driven gear 65 and a fourth driven gear 64 are arranged. The final drive gear 41 and the driven gears 61 to 65 are integrally attached to the counter shaft 14.

Here, the first speed drive gear 51 and the first speed driven gear 61 always mesh with each other to form a first gear stage gear train. Further, the second speed drive gear 52 and the second speed driven gear 63 are always meshed with each other to form a second gear stage gear train. Less than,
Similarly, the third speed drive gear 53 to the sixth speed drive gear 56,
The third speed driven gear 63 to the sixth speed driven gear 66 are always meshed with each other to form a third to sixth speed gear train.

Further, between the first speed drive gear 51 and the sixth speed drive gear 56 on the main shaft 13,
A dog gear clutch 71 for 6-speed transmission is attached. The 1-6 speed shift dog tooth clutch 71 includes a clutch hub (hereinafter, simply referred to as a hub) 71h integrally attached to the main shaft 13, and drive gears 51, 52.
Dog teeth 71d and 76d attached to the hub 71h
And a sleeve 71s that is slidably connected to the left and right and is capable of engaging and disengaging its internal tooth spline with respect to the dog tooth (71d or 76d) to which it slides. In the dog tooth clutch 71 for 1-6 speed shifting, the sleeve 71s is slid to the left and right on the hub 71h by the movement of the 1-6 shift fork 81 that holds the outer periphery of the sleeve 71s and engages with the dog tooth (71d or 76d). By combining, the first speed drive gear 51 or the sixth speed drive gear 56
Is rotated integrally with the main shaft 13. Therefore, the rotation of the main shaft 13 is transmitted to the counter shaft 14 while being decelerated or speeded up by the first shift stage gear train or the sixth shift stage gear train.

The second shaft on the main shaft 13
Between the high speed drive gear 52 and the third speed drive gear 53,
A dog gear clutch 72 for three-speed shifting is attached.
The dog gear clutch 72 for 2-3 speed shifting includes a hub 73h integrally attached to the main shaft 13 and dog teeth 72d and 73d attached to the drive gears 52 and 53.
And a sleeve 72s slidably coupled to the left and right with the hub 73h and capable of engaging and disengaging its own internal spline with respect to the dog tooth of the sliding destination. In the dog gear clutch 72 for 2-3 stage shifting, the sleeve 72s is slid left and right on the hub 72h with the movement of the 2-3 shift fork 82 that holds the outer periphery of the sleeve 72s, so that the dog tooth (72d or 73d) is moved. To engage the second speed drive gear 52 or the third speed drive gear 53.
Is rotated integrally with the main shaft 13. As a result, the rotation of the main shaft 13 is transmitted to the counter shaft 14 while being decelerated by the second shift speed gear train or the third shift speed gear train.

On the other hand, between the fourth speed driven gear 64 and the fifth speed driven gear 65 on the counter shaft 14,
A dog gear clutch 74 for fifth gear is attached. This 4-5 speed shift dog tooth clutch 74 includes a hub 74h integrally attached to the counter shaft 14,
Dog teeth 74d attached to each driven gear 64, 65,
75d, and a sleeve 74s slidably connected to the hub 74h in the left and right directions so as to be able to engage and disengage each internal tooth spline with respect to the dog tooth of the sliding destination. This 4-5 speed dog dog clutch 74
Then, the sleeve 74s is slid leftward and rightward on the hub 74h with the movement of the 4-5 shift fork 84 that holds the outer periphery of the sleeve 74s, and engages with the dog teeth (74d or 75d). 64 or fifth speed driven gear 65
Is rotated integrally with the counter shaft 14. As a result, the rotation of the main shaft 13 is transmitted to the counter shaft 14 at substantially the same speed as the main shaft 13 by the fourth gear stage gear train or while being accelerated by the fifth gear stage gear train. In addition, each dog tooth clutch 71, 7
2 and 74, the positions of the sleeves 71s, 72s, and 74s engaged with one of the dog teeth are referred to as engagement positions, and the sleeves 71s, 72s, and 7 separated from both dog teeth
The position of 4 s is called the disengagement position. Further, the rotation of the counter shaft 14 is transmitted to a differential (not shown) via a final drive gear 41 and a final driven gear 42 meshing with the final drive gear 41.

Here, each of the shift forks 81, 8 described above
2, 84 will be described. In the lower part of FIG. 1, the first shift fork shaft 91 and the second shift fork shaft 91 extend so as to extend parallel to the main shaft 13 and the counter shaft 14.
A shift fork shaft 92 is arranged. The 1-6 shift fork 81 and the 2-3 shift fork 82 are axially slidably mounted on the first shift fork shaft 91. The 4-5 shift fork 84 is attached integrally to the right end portion of the second shift fork shaft 92.

Further, the 1-6 shift forks 81,2-
A shift gate (1-6 shift gate 10) formed in an inverted U shape at the left end of each of the third shift fork 82 and the second shift fork shaft 92 is opened.
1, 2-3 shift gates 102 and 4-5 shift gates 104) are provided. Those shift gates 10
As shown in FIG. 2, reference numerals 1, 102, and 104 denote 4-5 shift gates 104 on the upper side (the front side of the paper surface in FIG. 1) and a lower side (the paper surface in FIG. 1) with the 1-6 shift gate 101 interposed therebetween. 2-3 shift gates 102 are arranged side by side in a group at the rear side). The positions of the shift gates 101, 102, 104 when the sleeves 71s, 72s, 74s are located at the disengaged position are referred to as neutral gate positions N. In addition, each sleeve 71s,
The position of each shift gate 101, 102, 104 when 72s and 74s are located at the engagement position is referred to as an engagement gate position. Furthermore, the shift gates 101, 102, and 104 that form a group are collectively referred to as a shift gate group. Further, as shown in FIG. 2, each shift gate 10
Shifter receiving grooves (U-shaped grooves) 101a, 102a, 10 formed in the center of 1, 102, 104 so as to be vertically connected.
As shown in FIG. 1, the tip of the shifter 1 is received by 4a. The shift shifter 1 is movable in the up-down direction (hereinafter referred to as the select direction) and the left-right direction (hereinafter referred to as the shift direction) in FIG.

Therefore, the shifter 1 for shifting is moved in the select direction to be received in the shifter receiving groove of one of the shift gates, and further, while moving in the shift direction, the shift gate is moved to the neutral gate position. By pushing from N, the shift fork connected to the shift gate is slid on the first shift fork shaft 91 or moves in the axial direction together with the second shift fork shaft 92. The numbers (I, II, ..., VI) shown on each shift gate correspond to each shift speed. For example, the 1-6 shift gate 101 is set to the I side (first speed) with respect to the neutral gate position N. If it is moved in the shift direction), it means that the gear is shifted to the first gear (however, these numbers are not actually displayed).

Next, a drive mechanism 300 for driving the shift shifter 1 in the select direction and the shift direction will be described with reference to FIGS. 3 and 4. In the description here, the R direction in FIG. 3 is the right, the L direction is the left, and the U direction.
The direction is called up and the D direction is called down. Shifting shifter 1
Is integrally mounted near the right end portion of the shifter support shaft 302 rotatably supported by the case 11 while extending in parallel with the shift fork shafts 91 and 92. As shown in FIG. 4, the select driven gear 30 that spreads in a fan shape in the circumferential direction of the shifter support shaft 302 is provided at an intermediate portion in the left-right direction of the shifter support shaft 302.
3 is attached. This select driven gear 303
The gear teeth 303a formed on the outer circumference of the gear teeth 304a formed on the select drive gear shaft 304 arranged in parallel with the shifter support shaft 302 extend in the axial direction.
It meshes with a. The select drive gear shaft 304 is a select motor (shifter drive means) 301.
Is the axis of rotation.

On the other hand, at the left end portion of the shifter support shaft 302, a shift driven arm 312 (see FIG. 4) formed so as to open downward in a bifurcated manner is rotatable with respect to the shifter support shaft 302. It is installed. The shift driven arm 312 holds the ball screw housing 313. Ball screw housing 3
13 is mounted on the ball screw shaft 314. Further, the ball screw shaft 314 is connected to the rotating shaft of the shift motor (shifter driving means) 311 via an Oldham coupling 315.

In the drive mechanism 300 having such a structure, the selection motor 301 is rotated to cause the operation shown in FIG.
As shown by a chain line, the select driven gear 303 rotates together with the shifter support shaft 302, and the shift shifter 1
Is selected. Further, since the ball screw shaft 314 is rotated by the rotation operation of the shift motor 311, the ball screw housing 313 moves left and right as indicated by the chain line in FIG. Therefore, the shifter support shaft 302 is pushed and pulled by the ball screw housing 313 through the shift driven arm 312 to move left and right, and the shift shifter 1 shifts. As shown in FIG. 3, a detent groove 302a is formed on the upper surface of the left end portion of the shifter support shaft 302. In the case 11 above the detent groove 302a, a ball 318a that can be projected / retracted downward is provided.
A ball-type stopper 318 having a is attached. The ball 318a is biased in the protruding direction by a spring 318b provided inside the stopper 318. Therefore, the ball 318a is fitted into the detent groove 302a, so that the shifter support shaft 302, that is, the shift shifter 1 is moved to each shift gate 101, 102, 10.
4 is positioned at a position where the gate 4 is positioned at the neutral gate position N (hereinafter, referred to as a shift direction neutral position).

Here, in the main drive mechanism 300, as shown in FIG. 3, a select direction automatic positioning mechanism (claim 2
(Corresponding to the "automatic positioning mechanism") is provided. This select direction automatic positioning mechanism 400
Includes a cam member 401 having a base end attached to the right end of the case 11. The cam member 401 extends downward from its base end portion and further extends leftward so that its tip end surface (cam surface) 401a reaches near the select driven gear 303. As shown in FIG. 5, the cam surface 401a is formed in a valley shape having a bottom at the center in the width direction. The through hole 40 is provided near the base end of the cam member 401.
1b is formed. In this through hole 401b, as shown in FIG.
As shown in, the right end of the shifter support shaft 302 is rotatably inserted.

Further, as shown in FIG. 3, the cam member 401
A ball holding member 403 is pivotally attached at its base end to the lower surface of the above by a pivot pin 402 so as to be swingable in the same direction as the select driven gear 303. The ball holding member 403 has a U-shaped intermediate portion that is connected to the base end portion, and further has a distal end portion (upward) extending along the select driven gear 303 to a radial intermediate portion thereof. Above U
A ball holding hole 403a is formed on the tip side of the character portion. Further, a fork portion 403b that opens upward is formed at the most distal end of the ball holding member 403. The fork portion 403b holds a swing pin 305 attached to the radial intermediate portion of the select driven gear 303.

On the other hand, as shown in FIG. 3, a base end portion of a leaf spring 404 is attached to the lower surface of the ball holding member 403 on the base end side of the U-shaped portion. The tip of the leaf spring 404 extends along the U-shaped portion of the ball holding member 403, and the tip reaches the outside of the ball holding hole 403a. Further, a recess 404a is formed inside the tip of the leaf spring 404. Then, as shown in FIG. 5, when the ball holding member 403 is not swinging with respect to the cam member 401, the bottom portion of the cam surface 401a, the inner side surface of the ball holding hole 403a, and the leaf spring 40.
The select ball 405 is held by the four recesses 404a. Two select springs 40 having an arm portion 406a are provided around the pivot pin 402.
6, 406 are attached in a double wound state. Arms 406a, 4 extending from each select spring 406
The tips of 06a are hooked on both side surfaces of the ball holding member 403, respectively.

In the select direction automatic positioning mechanism 400 configured as described above, as described above, the shift shifter 1 is placed on the 1-6 shift gate 101 to the other shift gates 10.
When the select motor 301 is rotationally operated to swing the select driven gear 303 so as to perform the select movement to the positions 2, 104, the swing is transmitted to the ball holding member 403 via the swing pin 305. Therefore, the tip end side of the ball holding member 403 is, as shown in FIG.
It swings with respect to the cam member 401 about 2. As a result, the select ball 405 moves outward in the ball holding hole 403a while rotating from the bottom of the cam surface 401a along the cam surface 401a. Therefore, the leaf spring 4
The tip of 04 is pushed outward by the select ball 405, and the leaf spring 404 has a select ball 405.
Urging force (that is, the cam surface 40
Utilizing the inclination of 1a, an urging force for returning the ball holding member 403 to the original position is generated. Further, the arm portion 406a of the select spring 406, which is caught on the side surface of the ball holding member 403 in the swinging direction, is also urged to return the ball holding member 403 to its original position.

In this state, the selection motor 30
The rotation operation of No. 1 is released and the selection motor 301
When it becomes free to rotate,
The ball holding member 403 and the select driven gear 303 are returned to their original positions by one biasing force, and the shift shifter 1 is returned toward the 1-6 shift gate 101. The shift ball 1 is positioned on the 1-6 shift gate 101 when the select ball 405 is housed in the bottom of the cam surface 401a.

In the drive mechanism 300, the selection motor 301 and the shift motor 311 for operating the shift shifter 1 operate by receiving a signal from the control unit CU shown in FIG. As a result, automatic shift control in the transmission 10 is performed. However, since the select direction automatic positioning mechanism 400 is provided, the shift shifter 1 is installed in the 1-6 shift gate 10.
It is not necessary to control the operation of the select motor 301 for returning the value to 1.

By the way, in order to perform a smooth gear shift by the gear shift shifter 1 driven in this way, the dog teeth (71d to 76d) of the gear to which the gear is shifted and the sleeves (71s, 72s, 74s) to be engaged therewith. It is necessary to synchronize the rotation of. Therefore, in the present transmission 10, as shown in FIG. 1, the synchromesh is provided on the first gear stage (minimum gear stage) side and the sixth gear stage (highest gear stage) side of the 1-6 dog tooth clutch 71. Mechanism (synchronizing means) 121, 126
Is provided. The 1-6 shift gate 101 corresponds to the "shift gate for synchronization stage" in the claims.

The synchromesh mechanism on the first shift stage side (hereinafter referred to as the 1st speed side synchromesh mechanism) 121 and the synchromesh mechanism on the sixth shift stage side (hereinafter referred to as the 6th speed side synchromesh mechanism) 126 include each drive gear 51. , 56 and cone portions 121a and 126a that are provided integrally with the main shaft 13 and extend toward the hub 71h along the main shaft 13. A hub 71h is provided on the tapered portion of each cone portion 121a, 126a.
And a blocking ring 12 having an external tooth spline protruding between the dog teeth 71d and 76d of each drive gear 51 and 56.
1b and 126b are mounted. In addition, synchronizer springs 121c and 122c are attached between the blocking rings 121b and 126b and the hub 71h.

The sleeve 71s and the 1-6 shift fork 81, which is moved by the shifter 1 for shifting, together with the hub 71h.
When moved rightward or leftward with respect to, the sleeve 71s first pushes the blocking ring (121b or 126b) through the synchronizer spring (121c or 126c) to move it to the right or left. At that time, friction occurs between the blocking ring (121b or 126b) and the cone portion (121a or 126a). The frictional force synchronizes the rotation of the sleeve 71s and the rotation of the dog teeth (71d or 76d). The positions of the sleeve 71s that actuate the synchronizing mechanisms 121 and 126 are referred to as the 1st speed side synchronization position and the 6th speed side synchronization position, respectively. Further, the positions of the shift shifter 1 when the sleeve 71s is positioned at the respective synchronization positions are referred to as the 1st speed side synchronous shift position P1 and the 6th speed side synchronous time shift position P6, respectively.

When shifting to the first speed or the sixth speed, after the synchronization is completed in this way, the synchronizer spring is further moved to the dog tooth side.
Escape into the groove (not shown) formed in the internal tooth spline. In this way, the internal spline of the sleeve 71s can be smoothly engaged with the blocking ring and the dog tooth. When shifting to the first speed and the sixth speed in this way, the first speed side synchronization mechanism 121 or 6 respectively.
The rotation synchronization is performed by the high speed side synchronization mechanism 126 as described above. However, in the present transmission 10, even when shifting to a gear stage other than the first speed and the sixth speed, the synchronization mechanism 1 is used.
21 and 126 are made to act.

The operation control of the clutch motor 31, the selection motor 301, and the shift motor 311 when shifting to a shift speed (intermediate shift speed) other than the first speed and the sixth speed is performed by the above-mentioned control unit CU.
In, the process is performed according to the flowchart shown in FIG. In step S1, in addition to the reduction gear ratio of the gear train of the current shift stage, as shown in FIG.
The opening degree θac of the accelerator AC and the opening degree θth of the throttle TH are read, and the target shift speed is set based on these conditions (running state).

In step S2, in order to turn off the main clutch 20, as shown in FIG. 11, a clutch operation command Cm (cl) is sent to the clutch motor 31 to operate it. In step S3, the main clutch 2
It is determined whether 0 is surely turned off. As shown in FIG. 2, the determination is made by a clutch sensor (stroke sensor) 38 mounted near the main clutch 20.
It is performed based on the detection signal from. Clutch sensor 3
Reference numeral 8 has a detection rod 38a extending toward the upper right end of the release fork 28. Clutch motor 3
When the upper part of the release fork 28 moves to the right and the main clutch 20 is turned off by the operation of 1, the upper part of the release fork 28 pushes it in the right direction while contacting the tip of the detection rod 38a. As a result, the detection signal is output from the clutch sensor 38. It is determined that the main clutch 20 is turned off (“YE
S)), the process proceeds to step S4, and when it is determined that it is not turned off yet ("NO"), the flow is temporarily terminated (END), and for example, detection of a flag set in step S2 (not shown). ), Directly above step S
Return to 2. It should be noted that returning to the immediately above step through the detection of such a flag is performed in the following steps S5, S8, S1.
It is also performed when the process proceeds to the "NO" side in 0 and S12.

In step S4, the shift gate (10) relating to the current shift stage being moved by the shifter 1 for shifting.
1, 102, 104) to return to the neutral gate position N together with the shifter 1 for shift, a shift operation command Cm (sf) is sent to the shift motor 311 to operate it. Furthermore, except when the operation of the selecting motor 301 has already been released (when the previous gear was the first speed or the sixth speed), the selecting operation command Cm (sl) that was sent to the selecting motor 301. Stop the output of.
As a result, the shift shifter 1 is selectively moved by the action of the select automatic positioning mechanism 400, and is placed on the 1-6 shift gate 101 (hereinafter, 1-6) located at the neutral gate position.
It is returned to the neutral position). In step S5, it is determined whether or not the shift shifter 1 is surely positioned at the 1-6 neutral position. The determination is made by selecting the select position detection signal Slp and the shift position detection signal S1 from encoders built in the motors 301 and 311 for detecting the rotation angles of the select motor 301 and the shift motor 311.
It is performed based on fp. When it is determined that the vehicle is located at the neutral position 1-6, the process proceeds to step S6, and 1-6
If it is determined that the vehicle is not in the neutral position, the process returns to step S4.

In step S6, it is determined whether the target shift speed set in step S1 is a high shift speed (low shift speed) with respect to the current shift speed. When in high gear,
That is, when the shift up is to be performed, the process proceeds to step S71, and when the shift speed is low, that is, the shift down is to be performed, the process proceeds to step S72. In step S71, in order to operate the 6th speed side synchronizing mechanism 126, the shift motor 311 is operated to move the shift shifter 1 to the 6th speed side synchronous shift position P6.
f) is sent and this is activated. In step S72, the shift motor 311 is operated so as to move the shift shifter 1 to the shift position P1 at the 1st speed side synchronization in order to operate the 1st speed side synchronizing mechanism 121.

In step S8, the rotation speed Nm of the main shaft 13 or the rotation speed Nc of the counter shaft 14 is caused by the action of each of the synchronizing mechanisms 121 and 126.
, It is determined whether or not the number of rotations of the dog tooth of the target shift speed matches. The rotation speed Nm of the main shaft 13 is detected by the main rotation sensor 17 arranged close to and above the fifth speed drive gear 55 as shown in FIGS. Nc is detected by the counter rotation sensor 18 mounted near and above the second speed drive gear 52. When it is determined that they match, the process proceeds to step S9, and when it is determined that they do not match, the original step (step S71 or step S7) is performed.
Return to 2).

In step S9, first, the shift shifter 1
The shift motor 311 is operated so as to return the position 1-6 to the neutral position. As a result, the 1-6 shift gate 101 is also pulled back by the shifter 1 and returned to the neutral gate position N. Next, the select motor 301 is operated so that the shift shifter 1 is selectively moved to the shift gate corresponding to the target shift stage (hereinafter referred to as the target shift gate). Next, in step S10, it is determined whether or not the shift shifter 1 is reliably positioned on the target shift gate. When it is determined that the vehicle is located on the target shift gate, the process proceeds to step S11, and when it is determined that the vehicle is not yet located, the process returns to step S9.

In step S11, the shift motor 311 is used to shift the shift shifter 1 in the shift direction corresponding to the target shift stage (hereinafter referred to as the target shift direction).
Operate. Next, in step S12, it is determined whether or not the shift shifter 1 has surely moved in the target shift direction. When it is determined that the movement in the target shift direction is completed, the process proceeds to step S13, and when it is determined that the movement is not completed yet, the process returns to step S11. In step S13, the clutch operation command Cm sent to the clutch motor 31 in order to turn on the main clutch 20.
The output of (cl) is stopped and the operation of the clutch motor 31 is released.

Hereinafter, from the first speed (low shift speed) to the second speed (high shift speed), which is performed in accordance with such a flow chart.
The shift operation to (1) will be described with reference to FIG. First, when the target shift speed (second speed) is set in the control unit CU (step S1), the main clutch 20 is turned off and the rotation input from the input shaft 12 to the main shaft 13 is lost (step S).
2). Therefore, the main shaft 13 has the first gear train (5) that is in the engaged state with the 1-6 dog clutch 71.
1, 61) and is driven to rotate by the counter shaft 14 that rotates at a lower speed than the main shaft 13. The rotation of the sixth speed drive gear 56, which is driven by the sixth speed driven gear 66 that rotates integrally with the counter shaft 14, is slower than the rotation of the main shaft 13. Further, the second speed drive gear 5 to be driven by the second speed driven gear 63 that rotates integrally with the counter shaft 14.
The rotation of 2 is slower than the rotation of the main shaft 13 and faster than the rotation of the sixth speed drive gear 56.

Thereafter, the shift shifter 1 is returned to the 1-6 neutral position (1-6N in FIG. 8) (step S4).
Therefore, the engagement between the sleeve 71s of the 1-6 dog tooth clutch 71 and the dog tooth 71d on the first speed drive gear 51 side is released. Then, the shift shifter 1 is moved to the sixth-speed-side synchronous shift position P6 (step S71). Therefore, the sixth speed side synchronizing mechanism 126 is actuated to decelerate the rotation of the main shaft 13 by the sixth speed drive gear 56. As a result, the rotation of the 2-3 dog tooth clutch 72 (sleeve 72s) that rotates integrally with the main shaft 13 and thus the main shaft 13 and the rotation of the dog tooth 72d on the second speed drive gear 52 side become uniform. Step S8). Thereafter, the shift shifter 1 moves the 2-3 shift gate 102 in the second speed shift direction II via the 1-6 neutral position (1-6N), and engages the sleeve 72s with the dog teeth 72d (steps S9-). Step S11). Then, the main clutch 20 is turned on (step S13), and this shift is completed.

Here, the dotted line c in FIG. 8 shows the movement path (movement distance) of the shift shifter 1 in this shift. As can be seen from this figure, the shift distance of the shift shifter 1 in the select direction in the above shift is equivalent to half the distance from one end to the other end of the shift gate group. Further, the chain line d in the figure shows the movement path of the shift shifter 1 at the time of upshifting from the third speed to the fourth speed. As can be seen from this figure, the shift distance of the shift shifter 1 in the select direction in the main shift is equivalent to the distance from one end to the other end of the shift gate group.

Next, the shift operation from the sixth speed (high speed) to the fifth speed (low speed) will be described. First, when the target shift speed (fifth speed) is set (step S1), the main clutch 20 is turned off (step S2). Therefore, the main shaft 13 has the 1-6 dog tooth clutch 7
It is rotationally driven by the counter shaft 14 that rotates at a higher speed than the main shaft 13 via the sixth gear train (56, 66) that is in engagement with 1. The rotation of the first speed drive gear 51, which is driven by the first speed driven gear 61 that rotates integrally with the counter shaft 14, is faster than the rotation of the main shaft 13. Further, the rotation of the fifth speed driven gear 65, which is driven by the fifth speed drive gear 55 that rotates integrally with the main shaft 13, is slower than the rotation of the counter shaft 14.

After that, the shift shifter 1 is moved to the 1st-speed side synchronous shift position P1 via the 1-6 neutral position (1-6N) (steps S4 to S72). Therefore, the 1st speed side synchro mechanism 121 operates to increase the speed of the main shaft 13 by the first speed drive gear 51 and further increase the speed of the 5th speed driven gear 65. As a result, the rotation of the 4-5 dog tooth clutch 74 that rotates integrally with the counter shaft 14 and the dog tooth 75d attached to the fifth speed driven gear 65.
And the rotation speed of (step S8). Thereafter, the shift shifter 1 moves the 4-5 shift gate 104 in the fifth speed shift direction V through the 1-6 neutral position (1-6N).
In this way, the sleeve 74s is engaged with the dog tooth 75d (steps S9 to S11), and the main clutch 2
0 is turned on (step S13), and this shift is completed.

Here, the dotted line e in FIG. 9 shows the movement path of the shift shifter 1 in this shift. As can be seen from this figure, the shift distance of the shift shifter 1 in the select direction in the above shift is equivalent to half the distance from one end to the other end of the shift gate group. Also,
A chain line f in the figure shows a movement path of the shift shifter 1 at the time of downshifting from the third speed to the second speed. As can be seen from this figure, the shift distance in the select direction of the shift shifter 1 in the main shift may be equivalent to the distance from one end to the other end of the shift gate group.

As described above, in the present transmission 10, the shift shifter 1 moves to the shift positions P1 and P6 during synchronization and then moves in the shift direction corresponding to the target shift speed. However, as can be seen from the movement paths of the shift shifter 1 shown in FIGS. 8 and 9, the maximum shift distance of the shift shifter 1 in the select direction until the shift is completed is from the one end to the other end of the shift gate group. The distance to is enough. As a result, the maximum time required to complete the shift can be shortened, and the shift times can be averaged.

[0051]

As described above, in the always meshing type transmission of the present invention, the synchronous gear shift gate is arranged in the middle of the other shift gates. Therefore, the shift distance of the shift shifter in the select direction at the time of shifting, that is, the distance from the shift gate for the current shift stage to the shift gate for the synchronous stage and from that to the shift gate for the target shift stage The maximum one of the distances can be made shorter than the maximum movement distance in the conventional transmission (the one in which the shift gate for the synchronous stage is arranged at the end of the shift gate group). Therefore, if the constant mesh transmission is used, the time required for gear shift control can be shortened and averaged, and smooth gear shift control can be performed. Further, by providing the automatic positioning mechanism, when the shifter driving means is in the inoperative state, the shift shifter is automatically returned to the position where the shift gate for the synchronous stage can be pushed and positioned. Therefore, the operation control of the shifter driving means for returning the shift shifter to the above position becomes unnecessary, and the shift control can be simplified.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a constant mesh transmission according to the present invention.

FIG. 2 is a plan view (direction arrow view in FIG. 1) of a shift gate arrangement in the transmission.

FIG. 3 is a side view (a view in the direction of arrows in FIG. 4) of a drive mechanism of a shift shifter in the transmission.

FIG. 4 is a front view of the drive mechanism.

FIG. 5 is a plan view (direction arrow view in FIG. 3) showing an automatic positioning mechanism in the transmission.

FIG. 6 is a plan view showing an automatic positioning mechanism in the transmission.

FIG. 7 is a flow chart for shift control of the constant mesh transmission.

FIG. 8 is a conceptual diagram showing a moving path of a shift shifter of the constant mesh transmission.

FIG. 9 is a conceptual diagram showing a moving path of a shift shifter of the constant mesh transmission.

FIG. 10 is a conceptual diagram showing a movement path of a conventional shifter.

FIG. 11 is a system diagram of the constant mesh transmission.

[Explanation of symbols]

 1 shifter 13 main shaft 14 counter shaft 20 main clutch 31 clutch motor 51-56 drive gear 61-66 driven gear 71, 72, 74 dog tooth clutch 81, 82, 84 shift fork 101 synchronous shift gate 102, 104 shift gate 121,126 synchromesh mechanism 301 selection motor 311 shift motor 400 selection direction automatic positioning mechanism

Claims (2)

[Claims] 1. A plurality of constantly meshing gear trains for shifting arranged between a main shaft and a counter shaft, and a gear train mounted on the main shaft or the counter shaft and mounted on the gear trains adjacent to each other. A plurality of dog tooth clutches each having a sleeve that is movable so as to engage and disengage with respect to the associated dog tooth, and the dog tooth clutches for the lowest speed and the highest speed of the plurality of dog tooth clutch shifting gear trains. And a plurality of shift gates connected to the sleeves,
A constant mesh transmission comprising a shift shifter for pushing one of these shift gates to move the sleeve connected to the shift gate, and shifter driving means for operating the shift shifter. Among the plurality of shift gates, a shift gate for a synchronous stage connected to the sleeve of the dog tooth clutch for the lowest shift stage and a dog gear clutch for the highest shift stage is arranged in the middle of the other shift gates. Constant mesh type transmission. 2. An automatic positioning mechanism for positioning the shift shifter at a position where the shift gate for the synchronous stage can be pushed when the shifter driving means is not operating. The constantly meshed transmission described.