JP2878881B2 - Constant mesh transmission - Google Patents

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 for a vehicle, and more particularly to an automatic transmission which performs automatic transmission control.

[0002]

2. Description of the Related Art A continuously meshing transmission includes a plurality of continuously meshing gear trains arranged between a main shaft (connected to and disconnected from an input shaft by a clutch) and a counter shaft. Have been. In addition, on the main shaft or the counter shaft, the gear is moved so as to be engaged with or disengaged from a dog tooth attached to an adjacent speed change gear train (actually, either the main shaft side gear or the counter shaft side gear). A plurality of dog tooth clutches having a free sleeve are also provided. When the sleeve engages with the dog teeth, the rotation of the main shaft is transmitted to the counter shaft via the speed change gear train to which the dog teeth are attached. Such a constant-mesh type transmission may 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 shifter selectively pushes any one of the plurality of shift gates connected to the sleeve in the plurality of dog tooth clutches to move the sleeve connected to the shift gate. All the shift gates are arranged as a group (shift gate group). The shifter shifts in a shift gate group in a direction for selecting a shift gate to be pushed (hereinafter, referred to as a select direction) (select movement) and a direction for pushing the selected shift gate (hereinafter, referred to as a select direction). (Shift direction) (shift movement).

Further, such a transmission includes, for example,
There is one provided with a synchronizing device as disclosed in Japanese Patent Publication No. 54-28894. In this case, a gear train for synchronization is attached to the ends of the main shaft and the counter shaft separately from the gear train for speed change. Then, at the time of shifting to each shift speed, the rotation of the synchronization gear train is accelerated or braked on the counter shaft side,
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 to be engaged.

However, such a synchronizing device has a problem that the weight of the transmission is increased because a synchronizing gear train and other synchronizing clutch means are provided separately from the shifting gear train. Therefore, in order to solve such a problem, a synchronizing means, that is, a transmission provided with a synchromesh mechanism only in the dog gear clutch for the lowest gear and the highest gear (hereinafter referred to as a minimum / maximum synchronous Transmission). In this gear, a gear other than the lowest gear and the highest gear (hereinafter referred to as an intermediate gear)
In the shifting process, the shift gate once pushes a shift gate (hereinafter referred to as a synchronous stage shift gate) connected to the sleeve of a dog tooth clutch equipped with the above-mentioned synchromesh mechanism (hereinafter referred to as dog dog clutch with synchro). Then, the synchronous stage sleeve is moved to the synchronous position at which the synchromesh mechanism operates. Then, by the action of the synchromesh mechanism, the rotation of the main shaft is accelerated / decelerated, that is, the rotation of the sleeve and the dog teeth of the dog gear clutch for the intermediate speed gear at the speed change destination is synchronized. Specifically, when shifting from a low gear to a high gear, the synchromesh mechanism at the highest gear operates to decelerate the main shaft. On the other hand, when shifting from a high gear to a low gear, the synchromesh mechanism at the lowest gear operates to increase the speed of the main shaft.
This makes it possible to perform rotation synchronization at the time of shifting to all shift speeds without providing a gear train other than the gear train for shifting. After the rotation is synchronized in this way, the shift gear shifter shifts the sleeve for the target shift stage into engagement with the dog teeth to complete the shift.

However, in the shift gate arrangement in the lowest and highest gear synchronous transmission proposed in Japanese Patent Application Laid-Open No. 61-92343, for example, a shift gate arrangement as shown in FIG. 10 is employed. That is, the shift gates I and VI for the synchronous stage connected to the sleeves of the dog gear clutch with synchro (the dog gear clutch for the lowest gear (first speed) and the highest gear (sixth gear)) are provided in each gear train. (In the order from the first gear train to the sixth gear train) in the transmission, 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,
First, as shown by a dotted line a in the figure, the shifter shifts from a position (hereinafter simply referred to as “up”) at which the shift gate I for synchronization stage disposed at the left end of the shift gate group can be pushed. Select movement is performed on the synchronous stage shift gate VI arranged at the right end of the gate group. Then, the shift stage VI is shifted so as to slightly push the synchronous stage shift gate VI, that is, to move the sleeve to the synchronous position. afterwards,
The shift gate II is again shifted on the shift gate II arranged at the left end of the shift gate group, and the shift gate II is shifted so as to push the shift gate II so that the sleeve connected thereto is located at the engagement position.

[0007]

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

The present invention has been made in view of such a problem, and provides a constant-mesh type transmission in which the shift distance of a shift shifter at the time of shifting can be averaged as short as possible. It is intended to be.

[0009]

In order to achieve the above-mentioned 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. Note that an automatic positioning mechanism may be provided, and when the shifter driving means is in a non-operation state, the shift shifter may be returned to and positioned on the synchronous shift gate.

[0010]

In the constant-mesh transmission in which the shift gate is arranged as described above, the moving distance of the shifter is at most
Distance from above the shift gate of the current shift stage arranged at the end of the shift gate group to above the synchronous shift gate arranged in the middle of the shift gate group and a target arranged therefrom at the end of the shift gate group The distance from the shift stage to the position above the shift gate, that is, the distance from one end to the other end of the shift gate group is sufficient. As described above, the maximum shift distance of the shifter in the select direction is reduced, so that the shift time is averaged. If an automatic positioning mechanism is provided,
When the shifter is not driven by the shifter driving means, it is automatically returned to the synchronous stage shift gate. Therefore, the operation control of the shifter driving means is simplified because there is no need to control the return. be able to.

[0011]

Preferred embodiments 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. The transmission 10
Is mounted on the engine E as shown in FIG. 11, and has an input shaft 12 connected to an output shaft (not shown) of the engine E and rotating. A main clutch 20 is mounted on the right side 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 disposed at a position facing the right end face of the flyhole 21.
And 2. The clutch plate 23 is arranged between the flyhole 21 and the pressure plate 22 so as to be sandwiched therebetween. This clutch plate 23 is rotatable to the right of the input shaft 12 (however, it is rotatable independently of the input shaft 12).
It is attached to the left end of. A facing (friction plate) 23 is provided on both left and right end surfaces of the clutch plate 23.
a and 23a are pasted.

A diaphragm spring 25 is disposed 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. Also, the main shaft 1 is located on the right side of the center of the diaphragm spring 25.
A release bearing 27 is arranged so as to surround 3. The release bearing 27 swings left and right of a release fork 28 extending upward from a right side thereof (a swing fulcrum 29 disposed at an intermediate portion in the vertical direction of the release fork 28).
Is performed in the center).

The left and right swing of the release fork 28 is caused by the operation of the clutch motor 31 mounted above the release fork 28 and the tension release of the release release spring 35 mounted between the upper left end of the case 11 and the upper portion of the release fork 28. It is done using power. 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 rightward on the ball screw shaft 32 rotated by the operation of the motor 31 pushes the upper end of the release fork 28 rightward.
The lower end side than 9 is moved to the left. In addition, the upper portion of the release fork 28 that has been swung in this way is pulled by the release release 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). 28 is moved to the right.

The main clutch 20 constructed as described above
Then, when the clutch motor 31 is not operated, the pressure plate 22 is pressed to the left by the diaphragm spring 25, and the clutch plate 23 is sandwiched between the pressure plate 22 and the flyhole 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 by the clutch plate 23 (that is, the main shaft). 13). On the other hand, when the clutch motor 31 operates, the release bearing 27 is moved leftward by the release fork 28. The release bearing 27 contacts the vicinity of the center of the diaphragm spring 25 and pushes it to the left to release the diaphragm spring 25 from pressing the pressure plate 22 to the left. As a result, the connection between the flyhole 21 and the clutch plate 23 is disconnected, and the rotation of the flyhole 21 is not transmitted to the clutch plate 23.

As shown in FIG. 1, a third speed drive gear 53, a second speed drive gear 5
Second, sixth-speed drive gear 56, first-speed drive gear 51, fifth-speed drive gear 55, and fourth-speed drive gear 54 are provided. The drive gears 51 to 56 are connected to the main shaft 13.
It is rotatably attached to.

Below the main shaft 13, a counter shaft 14 extending in parallel with the main shaft 13 is rotatably supported. On this counter shaft 14, a final drive gear 41, a third driven gear 63, a second
A speed driven gear 62, a sixth speed driven gear 66, a first speed driven gear 61, a fifth speed driven gear 65, and a fourth speed driven gear 64 are provided. 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 speed gear train. Further, the second speed drive gear 52 and the second speed driven gear 63 always mesh with each other to form a second gear stage gear train. Less than,
Similarly, a third speed driving gear 53 to a sixth speed driving gear 56,
The third driven gear 63 to the sixth driven gear 66 always mesh with each other to form a third to sixth 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 shifting is mounted. The dog gear clutch 71 for 1-6 speed shifting includes a clutch hub (hereinafter, simply referred to as a hub) 71 h integrally attached to the main shaft 13 and drive gears 51 and 52.
Dog teeth 71d, 76d attached to the hub 71h
And a sleeve 71s capable of engaging and disengaging its own internal spline with the dog tooth (71d or 76d) of the sliding destination. In the dog gear clutch 71 for 1-6 speed shifting, the sleeve 71s is slid left and right on the hub 71h by the movement of the 1-6 shift fork 81 sandwiching the outer periphery thereof, and is engaged with the dog teeth (71d or 76d). By combining them, the first speed drive gear 51 or the sixth speed drive gear 56
Is rotated integrally with the main shaft 13. For this reason, the rotation of the main shaft 13 is transmitted to the counter shaft 14 while being reduced or increased in speed by the first gear stage or the sixth gear stage.

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 mounted.
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, 73d attached to the respective drive gears 52, 53.
And a sleeve 72s that is spline-coupled to the hub 73h so as to be slidable left and right, and that can engage and disengage its own internal spline with the dog tooth of the sliding destination. In the dog gear clutch 72 for 2-3 speed shifting, the sleeve 72s is slid left and right on the hub 72h with the movement of the 2-3 shift fork 82 sandwiching the outer periphery thereof, and the dog teeth (72d or 73d) are formed. , The second speed drive gear 52 or the third speed drive gear 53
Is rotated integrally with the main shaft 13. Thus, the rotation of the main shaft 13 is transmitted to the counter shaft 14 while being reduced by the second gear stage or the third gear stage.

On the other hand, between the fourth driven gear 64 and the fifth driven gear 65 on the counter shaft 14,
A dog gear clutch 74 for -5-speed shifting is mounted. This 4-5 speed dog dog clutch 74 is provided with 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 that is spline-coupled to the hub 74h so as to be slidable left and right and that can engage and disengage its own internal spline with the dog tooth of the sliding destination. This dog gear clutch 74 for 4-5 speed shifting
Then, the sleeve 74s is slid left and right on the hub 74h with the movement of the 4-5 shift fork 84 sandwiching the outer periphery thereof, and engages with the dog teeth (74d or 75d), whereby the fourth-speed driven gear is engaged. 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 or at an increased speed by the fifth gear stage. Each dog tooth clutch 71, 7
2, 74, the positions of the sleeves 71s, 72s, 74s engaged with any dog teeth are referred to as engagement positions, and the sleeves 71s, 72s, 7 detached from both dog teeth.
The position of 4s is called a separation position. 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 therewith.

Here, each of the shift forks 81, 8
2 and 84 will be described. 1, the first shift fork shaft 91 and the second shift fork shaft 91 extend in parallel with the main shaft 13 and the counter shaft 14.
A shift fork shaft 92 is provided. The 1-6 shift fork 81 and the 2-3 shift fork 82 are mounted on the first shift fork shaft 91 so as to be slidable in the axial direction. The 4-5 shift fork 84 is attached to the right end of the second shift fork shaft 92 integrally therewith.

Further, 1-6 shift forks 81 and 2-
Shift gates (1-6 shift gates 10) formed at the left ends of the 3 shift fork 82 and the second shift fork shaft 92 are formed in an inverted U shape and open downward.
1, 2-3 shift gate 102 and 4-5 shift gate 104) are provided. Those shift gates 10
As shown in FIG. 2, reference numerals 1, 102, and 104 denote a 4-5 shift gate 104 on the upper side (on the front side of the paper surface in FIG. 1) and a lower side (a paper surface in FIG. 1) with the 1-6 shift gate 101 interposed therebetween. Are arranged side by side as a group such as a 2-3 shift gate 102 on the back side of the gate. The position of each shift gate 101, 102, 104 when each of the sleeves 71s, 72s, 74s is at the detached position is referred to as a neutral gate position N. Also, each sleeve 71s,
The positions of the shift gates 101, 102, and 104 when the 72s and 74s are at the engagement positions are referred to as engagement gate positions. Further, the group of shift gates 101, 102, and 104 are collectively referred to as a shift gate group. Also, as shown in FIG.
Shifter receiving grooves (U-shaped grooves) 101a, 102a, 10 formed at the center of 1, 102, 104 so as to be connected vertically.
As shown in FIG. 1, the tip of the shifter 1 is received in the shifter 4a. The shifter 1 is movable in the vertical direction (hereinafter, referred to as a select direction) and the horizontal direction (hereinafter, referred to as a shift direction) in FIG.

As a result, the shifter 1 moves in the select direction to be received in the shifter receiving groove of any one of the shift gates. By pushing from N, the shift fork connected to the shift gate is slid on the first shift fork shaft 91 or moves along with the second shift fork shaft 92 in the axial direction. The numbers (I, II,..., VI) shown on the respective shift gates correspond to the respective shift speeds. For example, the 1-6 shift gate 101 is shifted to the I side (first speed) with respect to the neutral gate position N. (In the shift direction), it indicates that the gear is shifted to the first gear (however, these numbers are not actually displayed).

Next, a drive mechanism 300 for driving the shifter 1 in the select direction and the shift direction will be described with reference to FIGS. In the description here, the R direction in FIG.
The direction is called up and the D direction is called down. Shifter for shifting 1
Is integrally mounted near the right end of a shifter support shaft 302 rotatably supported by the case 11 in a state of extending in parallel with the shift fork shafts 91 and 92. As shown in FIG. 4, a select driven gear 30 which fan-wise expands in a circumferential direction of the shifter support shaft 302 at a middle portion in the left-right direction of the shifter support shaft 302.
3 is attached. This select driven gear 303
Gear teeth 303a formed on the outer periphery of the gear teeth are formed to extend in the axial direction on a select drive gear shaft 304 disposed in parallel with the shifter support shaft 302.
a. The select drive gear shaft 304 is connected to a select motor (shifter drive means) 301.
It is a rotation axis.

On the other hand, at the left end of the shifter support shaft 302, a shift driven arm 312 (see FIG. 4) formed so as to open bifurcated downward is rotatable with respect to the shifter support shaft 302. Installed. The shift driven arm 312 sandwiches 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 a rotation shaft of a shift motor (shifter driving means) 311 via an Oldham coupling 315.

In the driving mechanism 300 having such a configuration, the selection motor 301 is rotated to operate, so that the driving mechanism 300 shown in FIG.
As shown by a dashed line in FIG. 3, the selection driven gear 303 rotates together with the shifter support shaft 302, and
Is selected. Further, the ball screw shaft 314 is rotated by the rotation of the shift motor 311, so that the ball screw housing 313 moves right and left as shown by a chain line in FIG. 3. Therefore, the shifter support shaft 302 is pushed and pulled by the ball screw housing 313 via the shift driven arm 312 to move left and right, and the shifter 1 for shift is shifted. As shown in FIG. 3, a detent groove 302a is formed on the upper surface of the left end of the shifter support shaft 302. In the case 11 above the detent groove 302a, there is provided a ball 318a which can be protruded and retracted downward.
A ball-type stopper 318 provided with is provided. The ball 318a is urged in a protruding direction by a spring 318b provided inside the stopper 318. For this reason, when the ball 318a fits in the detent groove 302a, the shifter support shaft 302, that is, the shifter 1 for speed change causes the shift gates 101, 102, and 10 to move.
4 is positioned at a neutral gate position N (hereinafter referred to as a neutral position in the shift direction).

As shown in FIG. 3, the drive mechanism 300 has an automatic select direction positioning mechanism.
400) is provided. This select direction automatic positioning mechanism 400
Is provided with a cam member 401 having a base end attached to the right end of the case 11. The cam member 401 extends downward from the base end thereof, further extends leftward, and reaches its distal end surface (cam surface) 401a near the selected driven gear 303. As shown in FIG. 5, the cam surface 401a is formed in a trough 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, FIG.
As shown in FIG. 7, the right end of the shifter support shaft 302 is rotatably inserted.

Also, as shown in FIG.
A ball holding member 403 is pivotally mounted at the base end of the lower surface of the base member by a pivot pin 402 so as to be swingable in the same direction as the selection driven gear 303. The ball holding member 403 has a U-shaped intermediate portion connected to the base end, and has a distal end extending (upward) to a radially intermediate portion along the selection driven gear 303. U above
A ball holding hole 403a is formed on the distal end side of the letter-shaped 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 sandwiches a swing pin 305 attached to a radially intermediate portion of the selection driven gear 303.

On the other hand, as shown in FIG. 3, a base end of a leaf spring 404 is attached to the base of the lower surface of the ball holding member 403 from 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 concave portion 404a is formed inside the distal end of the leaf spring 404. As shown in FIG. 5, when the ball holding member 403 is not swinging with respect to the cam member 401, the bottom of the cam surface 401a, the inner surface of the ball holding hole 403a, and the leaf spring 40
The select ball 405 is held by the four concave portions 404a. Around the pivot pin 402, two select springs 40 having an arm portion 406a are provided.
6,406 are attached in a double winding state. Arms 406a, 4 extending from each select spring 406
06a are hooked on both side surfaces of the ball holding member 403, respectively.

In the automatic select direction positioning mechanism 400 constructed as described above, the shifter 1 is moved from above the 1-6 shift gate 101 to the other shift gates 10 as described above.
When the selection driven motor 303 rotates and the selection driven gear 303 swings in order to select and move the selected gear 2, 104, the swing is transmitted to the ball holding member 403 via the swing pin 305. For this reason, the tip side of the ball holding member 403 is, as shown in FIG.
2 swings about the cam member 401. As a result, the select ball 405 moves outward from the bottom of the cam surface 401a in the ball holding hole 403a while rotating along the cam surface 401a. For this reason, the leaf spring 4
04 is pushed outward by the select ball 405, and the leaf spring 404 is provided with the select ball 405.
Biasing 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, an urging force for returning the ball holding member 403 to the original position is also generated in the arm portion 406a of the select spring 406 which is hooked on the side surface of the ball holding member 403 in the swing direction.

In this state, the selection motor 30
1 is released and its selection motor 301 is released.
Becomes free rotatable, the 2
With the two urging forces, the ball holding member 403 and the selection driven gear 303 are returned to their original positions, and the shift shifter 1 is returned toward the 1-6 shift gate 101. When the select ball 405 fits on the bottom of the cam surface 401a, the shifter 1 is positioned on the 1-6 shift gate 101.

In the drive mechanism 300, the select motor 301 and the shift motor 311 for operating the shift shifter 1 operate upon receiving a signal from the control unit CU shown in FIG. Thus, automatic transmission control in the transmission 10 is performed. However, since the automatic select direction positioning mechanism 400 is provided, the shifter 1 is
It is not necessary to control the operation of the selecting motor 301 for returning the motor to the upper position.

By the way, in order to perform a smooth shift by the shift shifter 1 driven in this way, the dog teeth (71d-76d) of the shift speed and the sleeves (71s, 72s, 74s) to be engaged therewith. Must be synchronized. Therefore, in the transmission 10, as shown in FIG. 1, the synchromesh is provided on the 1-6 dog tooth clutch 71 at the first speed (lowest speed) and the sixth speed (highest). Mechanism (synchronization means) 121, 126
Is provided. The 1-6 shift gate 101 corresponds to a "shift gate for a synchronous stage" in the claims.

A synchromesh mechanism (hereinafter referred to as a first-speed side synchronizing mechanism) 121 on the first speed stage side and a synchromesh mechanism (hereinafter referred to as a sixth-speed side synchronizing mechanism) 126 on the sixth speed side include respective drive gears 51. , 56 and cone portions 121 a and 126 a extending along the main shaft 13 toward the hub 71 h. A hub 71h is provided on the tapered portion of each of the cone portions 121a and 126a.
Ring 12 having external splines protruding between dog teeth 71d, 76d of each drive gear 51, 56
1b and 126b are placed. Note that synchronizer springs 121c and 122c are mounted between the blocking rings 121b and 126b and the hub 71h.

The hub 71h together with the 1-6 shift fork 81 in which the sleeve 71s is moved by the shifter 1
First, the sleeve 71s pushes the blocking ring (121b or 126b) via the synchronizer spring (121c or 126c) to move right or left. At that time, friction occurs between the blocking ring (121b or 126b) and the cone (121a or 126a). Then, the rotation of the sleeve 71s and the rotation of the dog tooth (71d or 76d) are synchronized by the frictional force. The positions of the sleeve 71s at which the synchronizing mechanisms 121 and 126 act as described above are referred to as a first-speed synchronization position and a sixth-speed synchronization position, respectively. Further, the positions of the shift shifter 1 when the sleeve 71s is positioned at each synchronous position are referred to as a first-speed synchronous shift position P1 and a sixth-speed synchronous shift position P6, respectively.

When shifting to the first speed or the sixth speed, after the synchronization is completed, the synchronizer spring is further moved toward the dog tooth side.
Escapes into a groove (not shown) formed in the internal spline. Thus, the internal splines of the sleeve 71s can smoothly engage with the blocking ring and the dog teeth. When shifting to the first speed and the sixth speed in this way, the first speed side synchronizing mechanism 121 or 6 respectively.
The above-described rotation synchronization is performed by the high-speed synchronization mechanism 126. However, in the transmission 10, even when shifting to a speed other than the first speed and the sixth speed, the synchronization mechanism 1
21, 126 are operated.

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

In step S2, in order to turn off the main clutch 20, a clutch operation command Cm (cl) is sent to the clutch motor 31 to operate it, as shown in FIG. In step S3, the main clutch 2
It is determined whether 0 has been reliably turned off. The determination is made by a clutch sensor (stroke sensor) 38 mounted near the main clutch 20 as shown in FIG.
This is performed based on the detection signal from. Clutch sensor 3
8 has a detection rod 38a extending toward the upper right end of the release fork 28. Motor 3 for clutch
When the upper portion of the release fork 28 is moved rightward by the operation of 1 and the main clutch 20 is turned off, the upper portion of the release fork 28 is pushed rightward while abutting on the tip of the detection rod 38a. As a result, a detection signal is output from the clutch sensor 38. It is determined that the main clutch 20 has been turned off ("YE
S)), the process proceeds to step S4, and if it is determined that the switch has not been turned off yet ("NO"), the flow is once ended (END), for example, detection of a flag set in step S2 (not shown) ) Directly above step S
Return to 2. The return to the immediately above step through the detection of the flag is performed in the following steps S5, S8, S1
This is also performed when the process proceeds to the “NO” side in 0 and S12.

In step S4, the shift gate (10
(1, 102, 104) together with the shifter 1 for shifting, the shift operation command Cm (sf) is sent to the shift motor 311 to operate it. Further, the select operation command Cm (sl) sent to the select motor 301 except for the case where the operation of the select motor 301 has already been released (when the previous shift stage is the first speed or the sixth speed). Stop output of
As a result, the shifter 1 for shifting is selectively moved by the action of the automatic selection positioning mechanism 400, and is moved above the 1-6 shift gate 101 (hereinafter, 1-6) at the neutral gate position.
Neutral position). In step S5, it is determined whether or not the shifter 1 is securely located at the 1-6 neutral position. The determination is made based on the selection position detection signal Slp and the shift position detection signal Slp from the encoders incorporated in the motors 301 and 311 in order to detect the rotation angles of the selection motor 301 and the shift motor 311.
This is performed based on fp. When it is determined that the vehicle is located at the 1-6 neutral position, the process proceeds to step S6, and 1-6.
If it is determined that it is not located at the neutral position, the process returns to step S4.

In step S6, it is determined whether or not the target gear set in step S1 is a higher gear than the current gear (low gear). When in high gear,
That is, the process proceeds to step S71 when upshifting is to be performed, and proceeds to step S72 when the shift stage is low, that is, when downshifting is to be performed. In step S71, the shift operation command Cm (s) is issued to the shift motor 311 so as to move the shifter 1 for shifting to the shift position P6 at the time of synchronizing with the sixth speed in order to operate the sixth-speed side synchronizing mechanism 126.
f) and activate it. In step S72, the shift motor 311 is operated to move the shift shifter 1 to the first-speed synchronization shift position P1 in order to operate the first-speed side synchronization 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 controlled by the operation of the respective synchronization mechanisms 121 and 126.
Is determined to be equal to the number of revolutions of the dog teeth at the target gear position. 1 and 11, the rotation speed Nm of the main shaft 13 is detected by a main rotation sensor 17 disposed close to and above the fifth speed drive gear 55, and the rotation speed Nm of the counter shaft 14 is determined. Nc is detected by a counter rotation sensor 18 mounted close to and above the second speed drive gear 52. If it is determined that they match, the process proceeds to step S9, and if it is determined that they do not match, the process returns to the original step (step S71 or step S7).
Return to 2).

In step S9, first, the shift shifter 1
To the 1-6 neutral position. Accordingly, the 1-6 shift gate 101 is also returned to the neutral gate position N so as to be drawn by the shifter 1. Next, the select motor 301 is operated to selectively move the shifter 1 onto a shift gate corresponding to the target shift speed (hereinafter, referred to as a target shift gate). Next, in step S10, it is determined whether or not the shifter 1 has been reliably positioned on the target shift gate. When it is determined that it is located on the target shift gate, the process proceeds to step S11, and when it is determined that it is not located yet, the process returns to step S9.

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

Hereinafter, the first gear (low gear) to the second gear (high gear) performed according to such a flowchart will be described.
The speed change operation will be described with reference to FIG. First, when the target gear (second speed) is set in the control unit CU (step S1), the main clutch 20 is turned off, and there is no rotation input from the input shaft 12 to the main shaft 13 (step S1).
2). For this reason, the main shaft 13 is engaged with the 1-6 dog tooth clutch 71 in the first speed gear train (5
1, 61), it is rotationally driven by the counter shaft 14 which 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 driving gear 5 driven by the second speed driven gear 63 rotating integrally with the counter shaft 14 is provided.
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 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 teeth 71d on the first speed drive gear 51 side is released. Then, the shifter 1 for shifting is moved to the sixth synchronizing side shift position P6 (step S71). For this reason, the sixth-speed side synchronizing mechanism 126 operates to reduce the rotation of the main shaft 13 by the sixth-speed drive gear 56. As a result, the rotation of the main shaft 13, that is, the 2-3 dog tooth clutch 72 (sleeve 72 s) that rotates integrally with the main shaft 13, and the rotation of the dog tooth 72 d on the second speed drive gear 52 side become the same speed ( Step S8). Thereafter, the shifter 1 shifts the 2-3 shift gate 102 in the second speed shift direction II via the 1-6 neutral position (1-6N) to engage the sleeve 72s with the dog tooth 72d (steps S9 to S9). Step S11). Thereafter, the main clutch 20 is turned on (step S13), and this shift is completed.

Here, the dotted line c in FIG. 8 indicates the moving path (moving distance) of the 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 only half the distance from one end to the other end of the shift gate group. Further, a chain line d in the figure indicates a moving path of the shifter 1 when shifting up 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 actual shift is equivalent to the distance from one end to the other end of the shift gate group.

Next, the shifting operation from the sixth speed (high gear) to the fifth gear (low gear) will be described. First, when the target shift speed (fifth speed) is set (step S1), the main clutch 20 is turned off (step S2). For this reason, the main shaft 13 is provided with the 1-6 dog tooth clutch 7.
Through the sixth speed gear train (56, 66) in the engaged state with the gear 1, the rotation is driven by the counter shaft 14 rotating at a higher speed than the main shaft 13. The rotation of the first speed drive gear 51 driven by the first speed driven gear 61 rotating integrally with the counter shaft 14 is faster than the rotation of the main shaft 13. In addition, the rotation of the fifth speed driven gear 65 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.

Thereafter, the shifter 1 is shifted to the first-speed side synchronization shift position P1 via the 1-6 neutral position (1-6N) (steps S4 to S72). Therefore, the first-speed side synchronization 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 fifth speed driven gear 65. As a result, the rotation of the 4-5 dog tooth clutch 74, which rotates integrally with the counter shaft 14, and the dog teeth 75d attached to the fifth driven gear 65
Becomes constant speed (step S8). Hereinafter, the shifter 1 is moved through the 1-6 neutral position (1-6N) through the 4-5 shift gate 104 in the fifth shift direction V.
Thus, 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 moving path of the 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 only half the distance from one end to the other end of the shift gate group. Also,
A chain line f in the figure indicates a moving path of the shifter 1 during downshifting from the third speed to the second speed. As can be seen from this figure, the shift distance of the shift shifter 1 in the select direction in the actual shift is equivalent to the distance from one end to the other end of the shift gate group.

As described above, in the transmission 10, the shifter 1 once shifts to the synchronous shift positions P1 and P6, and then moves in the shift direction corresponding to the target shift speed. However, as can be seen from the movement path of the shifter 1 shown in FIGS. 8 and 9, the shift distance of the shifter 1 in the select direction until the shift is completed is at most from one end to the other end of the shift gate group. It is sufficient for the distance to. As a result, the maximum time required for completing the shift can be reduced, and the shift time can be averaged.

[0051]

As described above, in the constant mesh transmission according to the present invention, the shift gate for the synchronous stage is arranged in the middle of the other shift gates. For this reason, the shift distance of the 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 shift stage and the distance from there to the shift gate for the target shift stage. The largest of the distances can be made shorter than the maximum moving distance of the conventional transmission (the shift gate for the synchronous stage is arranged at the end of the shift gate group). Therefore, by using the constant mesh transmission, the time required for the shift control can be reduced and averaged, and smooth shift control can be performed. In addition, by providing the automatic positioning mechanism, when the shifter driving unit is deactivated, the shift shifter is automatically returned to a position where the shift stage shift gate can be pushed and positioned. Therefore, it is not necessary to control the operation of the shifter driving means for returning the shifter to the above position, and the shift control can be simplified.

[Brief description of the drawings]

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

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

3 is a side view of a drive mechanism of a shifter in the transmission (a view as seen in a direction indicated by an arrow in FIG. 4).

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

FIG. 5 is a plan view (a direction arrow 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 flowchart for gear shift control of the constant mesh transmission.

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

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

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

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Shifter 13 for shift 13 Main shaft 14 Counter shaft 20 Main clutch 31 Motor for clutch 51-56 Driving gear 61-66 Driven gear 71, 72, 74 Dog tooth clutch 81, 82, 84 Shift fork 101 Shift gate for synchronous stage 102, 104 shift gate 121, 126 synchromesh mechanism 301 select motor 311 shift motor 400 select direction automatic positioning mechanism

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F16H 61/26-63/38 F16H 3/08

Claims (2)

(57) [Claims] 1. A plurality of constantly meshing speed change gear trains disposed between a main shaft and a counter shaft, and mounted on the main shaft or the counter shaft and respectively mounted on adjacent speed change gear trains. A plurality of dog-tooth clutches having a sleeve movable to engage and disengage with the dog teeth, and a dog-tooth clutch for a lowest speed stage and a highest speed stage among the plurality of dog-tooth clutch speed change gear trains A plurality of shift gates connected to each of the sleeves;
In a constant-mesh transmission, which includes a shifter for shifting one of these shift gates to move the sleeve connected to the shift gate, and a shifter driving means for operating the shifter for shifting. Wherein, of the plurality of shift gates, a synchronous shift gate connected to the sleeve of the dog gear clutch for the lowest gear and the highest gear is arranged in the middle of the other shift gates. Constant mesh transmission. 2. An automatic positioning mechanism for positioning the shifter at a position where the shift gate for the synchronous stage can be pushed when the shifter driving means is not operated. A constant mesh transmission as described in the above.