JPH041231B2 - - Google Patents

Description

Detailed Description of the Invention A. Object of the Invention (1) Industrial Field of Application The present invention relates to a vehicle transmission, and particularly to a vehicle transmission that is provided between an input shaft and an output shaft and has a plurality of selectively established gear stages. A main transmission mechanism having a gear train and a plurality of synchronizing mechanisms driven by a shift fork for changing gears supported by a plurality of fork shafts to selectively establish the gear train; an auxiliary transmission mechanism having a reduction gear train for making the speed even lower than the lowest gear of the mechanism, and a synchronization mechanism for extremely low speed switching driven by a shift fork for extremely low speed switching to establish the transmission gear train; The present invention relates to a vehicle transmission of the type provided.

(2) Conventional technology A main transmission mechanism having four or more forward gears,
When configuring a transmission with multiple transmission mechanisms having gear trains to achieve an extremely low speed that is even lower than the lowest gear of the main transmission mechanism, multiple shifts are required to perform the gear change operation. Although it would be desirable to define the arrangement of forks and their forkshafts without significantly changing the prior art, no transmission has hitherto been realized that satisfies such requirements.

(3) Problems to be Solved by the Invention The present invention has been made in view of the above circumstances, and it is an object of the present invention to add an auxiliary transmission mechanism without significantly changing the arrangement of the shift fork and fork shaft in the entire transmission mechanism. To provide a vehicle transmission in which the structure of the shift operation system for the sub-transmission mechanism is as simple as possible, the design is easy, and the shift operation to an extremely low gear can always be performed quickly and accurately. The purpose is to provide.

B. Structure of the Invention (1) Means for Solving the Problems In order to achieve the above object, the present invention provides a multi-speed gear that is provided between an input shaft and an output shaft and that can be selectively established. a main transmission mechanism having a plurality of synchronizing mechanisms driven by shift forks for changing gears supported by a plurality of fork shafts in order to selectively establish the gear trains; and an acid transmission mechanism thereof. A type having a reduction gear train for lowering the speed even lower than the lowest gear position, and an auxiliary transmission mechanism having an extremely low speed switching synchronization mechanism driven by an extremely low speed switching shift fork to establish the reduction gear example. In a vehicle transmission, a pole integrally supports a shift fork for extremely low speed switching and can slide between a first position in which the shift fork is activated and a second position in which the shift fork is deactivated. A low-speed forkshaft is supported by the transmission case parallel to and spaced apart from each forkshaft of the main transmission mechanism, and supports a switching shift fork for establishing a gear train of the lowest gear of the main transmission mechanism. The fork shaft supports an extremely low speed fork head that can slide on the fork shaft in response to a shift operation to an extremely low speed, and in conjunction with this extremely low speed fork head, the extremely low speed fork shaft is moved to the first position. In order to move between the second positions, one end of a lever whose middle part is swingably supported via a pivot in the transmission case is connected to the extremely low speed fork head, and the other end is connected to the extremely low speed fork head. Each is connected to a shaft.

(2) Function By simply adding a few parts to the existing main transmission mechanism, such as the fork head for extremely low speeds, the fork shaft for extremely low speeds, and the only lever between the fork head and the shaft for extremely regular jobs, Since the shift operation system of the transmission mechanism can be easily attached, there is no need to significantly change the arrangement of each part of the main transmission mechanism. Moreover, by slidably supporting the fork head for extremely low speeds on the existing fork shaft that supports the shift fork for establishing the lowest gear position of the main transmission mechanism, the fork head for extremely low speeds is positioned adjacent to the lowest gear position of the main transmission mechanism. A reasonable shift pattern with low speed positions can be obtained.

In addition, particularly in relation to the fact that the fork shaft of the main transmission mechanism that slidably supports the fork head for extremely low speed and the fork shaft for extremely low speed that integrates the shift fork for extremely low speed switching are arranged parallel to each other, By a simple seesaw movement of the lever around the pivot axis, the sliding displacement of the very low speed fork head can be easily converted into the sliding displacement of the very low speed fork shaft along the sliding direction.

Furthermore, by the see-saw action of the single lever mentioned above, the sliding displacement of the very low speed fork head is converted into the displacement of the very low speed fork shaft and eventually the shift fork, so this lever can be omitted and the shift fork for very low speed switching is The bending rigidity of the shift fork can be kept low compared to a shift fork that is made longer, and the sliding resistance of the fork shaft for very low speeds is reduced.

(3) Embodiment An embodiment of the present invention will be described below with reference to the drawings. First, in FIG. 1, the engine E is placed horizontally at the front of the vehicle body, that is, its crankshaft 1 is perpendicular to the direction of travel of the vehicle. It is arranged like this. A transmission device consisting of a clutch 2, a transmission 3, a front wheel drive actuator 4 and a transfer 5 is disposed on one side of the engine E. The driving force of engine E is provided by clutch 2 and transmission 3.
is transmitted to the front wheel drive actuating device 4 via the drive shafts 6, 7, constant velocity joints 8, 9, transmission shafts 10, 11, and constant velocity joints 12, 13 to the left and right front wheels 14, 15. communicated. Further, the driving force of the engine E is selectively transmitted to the drive shaft 16 via the transmission 3 and the transfer 5. The driving force of the drive shaft 16 is transmitted to the rear wheel drive differential 20 via the universal joint 17, the propeller shaft 18, and the universal joint 19, and from the differential 20 to the drive shaft 2.
1, 22, constant velocity joint 23, 24, transmission shaft 2
5, 26 and constant velocity joints 27, 28 to the left and right rear wheels 29, 30.

In FIG. 2 showing details of the transmission device, a clutch case 32 is integrally secured to one side of a crankcase 31 of an engine E, and a transmission case 33 is further integrally secured to this clutch case 32.

A conventionally known clutch 2 is housed in the clutch case 32, and a transmission 3 is housed in the transmission case 33. The transmission 3 is a main transmission mechanism 36
and a sub-transmission mechanism 37, and a main transmission mechanism 36.
is a first speed gear train G1, a second speed gear train G2, and a third speed gear train G between an input shaft 38 coaxial with the crankshaft 1 and an output shaft 39 parallel to the input shaft 38.
3. A fourth speed gear train G4, a fifth speed gear train G5, and a reverse gear train Gr are provided. The driving force transmitted from the input shaft 38 to the output shaft 39 via the selected gear train among these gear trains G1, G2, G3, G4, G5, and Gr is transmitted to the output shaft at the end closer to the engine E. It is output from an output gear 40 provided at 39.

Referring also to FIG. 3, the sub-transmission mechanism 37 is as follows:
It is used for extremely low speeds below the first speed when all axes are driven, and the input shaft 38 and output shaft 3
It has an intermediate shaft 70 and a sub-shaft 71 parallel to the transmission case 9, and is disposed in a portion of the transmission case 33 closer to the clutch 2. The intermediate shaft 70 is connected to the clutch case 32
The intermediate shaft 70 is fixedly supported at both ends by a transmission case 33, and a gear 72 that is integrated with the input shaft 38 to constitute the first gear train G1 is constantly meshed with the intermediate shaft 70. A sub-input gear 73 is rotatably supported. Further, the sub-width 71 is rotatably supported by the clutch case 32 and the transmission case 33, and the sub-shaft 71 has an output shaft 3.
A sub-output gear 75 is integrated with the reduction gear 41 integrated with the gear 9 . In addition, the sub input gear 7
3 and a gear 77 that is relatively rotatably supported by the subshaft 71 are always meshed to form a reduction gear train 78. The auxiliary input gear 73, the reduction gear train 78, and the auxiliary output gear 75
constitutes an extremely low speed gear train Gsl.

The auxiliary input gear 73 and the gear 76 are integrated and are provided at both ends of a cylindrical body 74 with a bearing 79 interposed between it and the intermediate shaft 70 . That is, the auxiliary input gear 73 is integrated with one end of the cylindrical body 74 on the side of the clutch case 32, and the gear 76 is integrated with the other end of the cylindrical body 74. Further, a cylindrical collar 81 having a support flange 80 on the side of the auxiliary input gear 73 and surrounding the intermediate shaft 70 is disposed between the auxiliary input gear 73 and the clutch case 32. A thrust bearing 8 is provided between the 80 and the auxiliary input gear 73.
2 is interposed.

On the other hand, the gear 76 and the transmission case 33
A thrust bearing 83, a washer 84, a disc spring 85, and a washer 86 are interposed in order from the gear 76 side.

When the sub-transmission mechanism 37 is assembled, the intermediate shaft 70 has the cylindrical body 74 and the collar 81 in a state where the sub-input gear 73 and the gear 76 are meshed with the gear 72 of the input shaft 39 and the gear 77 of the sub-shaft 71, respectively. It is inserted through the tube, and is basically formed into a straight columnar shape. Furthermore, a rotation stopper projection 87 is provided on one end surface of the intermediate shaft 70 on the clutch case 32 side.
is installed protrudingly. On the other hand, in the clutch case 32,
A support hole 88 having a circular cross section is bored into which one end of the intermediate shaft 70 is fitted and supported.
A recess 89 into which the rotation stopper protrusion 87 is fitted is provided on the bottom surface of the recess 89 .

In FIG. 4, the rotation stopper projection 87
is formed so that its cross section is approximately semicircular, and the cross section of the recess 89 is also formed in a semicircular shape corresponding to the rotation stopper protrusion 87.

The transmission case 33 also has a support hole 90 with a circular cross section that fits and supports the other end of the intermediate shaft 70.
is provided.

Further, the subshaft 71 is rotatably supported by the clutch case 32 and the transmission case 33, and is supported by recesses 91 and 92 provided in the clutch case 32 and the transmission case 33, respectively.
is supported via bearings 93 and 94.

Referring again to FIG. 2, the gear box 44 of the front wheel drive differential 4 is rotatably supported by the clutch case 32 and the transmission case 33. The reduction ring gear 42 meshing with the reduction ring gear 4
Two smaller drive gears 43 are fixed in parallel. In addition, a pair of left and right front wheel drive shafts 6 and 7 are protruded and arranged to face each other in the gear box 44, and a support shaft 45 that is perpendicular to the drive shafts 6 and 7 is arranged between the two drive shafts 6 and 7. Fixed. Also, bevel gears 46 and 47 are fixed to both ends of the support shaft 45, and bevel gears 46 and 47 are fixed to the inner ends of the drive shafts 6 and 7.
Bevel gears 48 and 49 meshing with gear 7 are spline-coupled.

Clutch case 32 and transmission case 3
3 extends to the rear of the front wheel drive differential 4, and a transfer case 50 is integrated with the rear end of the clutch case 32 to form a chamber 52 for accommodating the transfer 5. Fixed. The transfer 5 includes a transfer shaft 53 that is parallel to the pair of drive shafts 6 and 7, and the transfer shaft 53 is connected to each of the cases 32 and 3.
It is rotatably supported by 3 and 50. A driving gear 43 integral with the gear box 44 is disposed at the end of the transfer shaft 53 closer to the transmission case 33.
A driven gear 54 that is always in mesh with the transfer shaft 53 and the driven gear 54 is rotatably supported.
A gear clutch mechanism 55 is provided between the two to connect and disconnect power transmission therebetween.

The gear clutch mechanism 55 includes a gear 56 integrally provided on one side of the driven gear 54, and a gear 58 provided at one end of a collar 57 spline-coupled to the transfer shaft 53, and is slidable in the axial direction. A sleeve 59 that is always meshed with the gear 58 and can be engaged with and detached from the gear 56, a yoke 60 that is engaged with the outer periphery of the sleeve 59, and a transfer shaft 5 for slidingly driving the yoke 60.
3 and a swing shaft 61 which is pivoted on the clutch case 32 and perpendicular to the clutch case 32. An actuator 62 such as a negative pressure actuator is connected to this swing shaft 61, and the swing shaft 61, that is, the yoke 60 is driven to swing by the actuator 62.

In this gear clutch mechanism 55, when the actuator 62 swings the yoke 60 to the right in FIG. The driving force of the gear 54 is transferred to the Lancer shaft 53.
transmitted to. Furthermore, when the yoke 60 is swung to the left as shown in FIG. be done.

A drive bevel gear 63 is fixed to the end of the transfer shaft 53 on the transfer case 50 side, and the drive bevel gear 63 meshes with a driven bevel gear 64 . The driven bevel gear 64 is integrally provided at the end of the drive shaft 16.
is disposed perpendicular to the transfer shaft 53 and is rotatably supported by a bearing sleeve 66 disposed astride the clutch case 32 and transfer case 50.

Next, the configuration for selecting each gear train G1, G2, G3, G4, G5, Gr in the main transmission mechanism 36 of the transmission 3 and the very low speed gear train Gsl in the auxiliary transmission mechanism 37 will be described. The output shaft 39 between the second speed gear trains G1 and G2 is connected to the select sleeve 96 and the gear trains G1 and G2 by moving left and right.
A first switch for switching the connection state between G2 and the output shaft 39;
A synchronizing mechanism 97 for switching to two speeds is installed, and a shift fork 98 for switching to first and second speeds is engaged with the select sleeve 96. Further, the input shaft 38 between the third and fourth speed gear trains G3 and G4 is provided with third and fourth gears that switch the connection state between both the gear trains G3 and G4 and the input shaft 38 by moving a select sleeve 99 to the left or right. A speed switching synchronization mechanism 100 is installed, and a shift fork 101 for third and fourth speed switching is engaged with the select sleeve 99. Further, at the end of the input shaft 38 on the side remote from the clutch 2,
A fifth speed switching synchronizing mechanism 102 for switching the connection state with the input shaft 38 of the fifth speed gear train G5 is installed, and a fifth speed switching shift fork 104 is engaged with a select sleeve 103 of the mechanism 102. be done.

The reverse gear train Gr is provided integrally with the drive gear 105 integrated with the input shaft 38 and the select sleeve 99 of the first and second speed switching synchronization mechanism 97, and is prevented from rotating relative to the output shaft 39. driven gear 1
06, and an idle gear 107 that is movable between a position in which it meshes with the drive gear 105 and a driven gear 106, and a position in which it disengages.
In other words, as shown in FIG.
The idler gear shaft 108 is slidably supported on an idler gear shaft 108 that is fixedly supported at the idler gear shaft 108 . This idle gear 10
7 is held by a reverse shift fork 109, and by the operation of the shift fork 109, the idle gear 107 is moved to a position where it meshes with both gears 105 and 106 to establish a reverse gear train Gr. , 106 and the position where the meshing state is released.

In the sub-transmission mechanism 37, the sub-shaft 71 has a gear 7.
A synchronizing mechanism 110 for extremely low speed switching is installed to switch the connection state between 7 and the subshaft 71, and this mechanism 1
An extremely low speed switching shift fork 112 is engaged with the select sleeve 111 of No. 10.

Figure 6 shows the shift pattern, where N is the neutral position, is the 1st gear position, is the 2nd gear position, is the 3rd gear position, is the 4th gear position, is the 5th gear position, and R
is the reverse drive position, and an extremely low speed position SL is provided adjacent to the first speed position.

According to such a shift pattern, each of the shift forks 98, 101, 104, 109, 11
2 are arranged as shown in FIGS. 7 to 9.

That is, a shaft holder 115 is fixed to the clutch case 32 facing the transmission case 33 side, and between the shaft holder 115 and the transmission case 33 there is a shaft parallel to the input shaft 38 and the output shaft 39. 1st forkshaft 1
16 is fixed. As shown in FIG. 10, the shift holder 115 is provided with an overhang part 117 that overhangs from the clutch case 32 toward the front wheel drive actuating device 4 side, and the first fork shaft 116 is fitted into this overhang part 117 to support it. A support hole 118 is provided for this purpose. Moreover, the overhang portion 117 is connected to the reduction ring gear 4.
A gap 119 is formed between the clutch case 32 and the periphery of the clutch case 32, so that the reduction ring gear 42 is sandwiched between the clutch case 32 and the clutch case 32.

Clutch case 32 and transmission case 3
3, second and third forkshafts 120, 121 parallel to the first forkshaft 116 are supported so that they can reciprocate within a limited range along their axial directions. The first fork shaft 116 includes a fork head 122 for switching between the first and second speeds, which integrally has a shift fork 98 for switching between the first and second speeds, and a fork head 123 for extremely low speeds.
and are slidably supported. The second fork shaft 120 also has a fork head 124 for reversing.
5th speed fork head 1 which integrally has a 3rd and 4th speed switching fork head 125 which integrally has a 3rd and 4th speed switching shift fork 101 and a 5th speed shift fork 104.
26 is slidably supported, and the third fork shaft 121 has an extremely low speed shift fork 1.
12 is fixed.

The outer surface of the first forkshaft 116 is provided with three recesses 127 spaced apart in the axial direction, corresponding to the fork heads 122 for switching between the first and second speeds.
22 includes balls 129 that are biased by the spring force of a spring 128 in a direction to fit into the recesses.
is retained. This constitutes a day tent mechanism, and the fork head 122 for switching between the first and second speeds, that is, the shift fork 98 for switching between the first and second speeds,
The select sleeve 69 is moved to the left in FIG. 2 to establish the first gear (left position in FIG. (center position in the figure) and
By moving the select sleeve 96 to the right in FIG. 2, it can be moved in a controlled manner between the position where the second gear is established (the right position in FIG. 8).

Furthermore, on the outer surface of the first forkshaft 116,
Three recesses 130 are provided at intervals in the horizontal axis direction at positions corresponding to the third and fourth speed switching fork heads 125 that are slidably supported by the second forkshaft 120, and the recesses 130 are fitted into these recesses 130. A mating ball 131 is provided on the convex portion 132 of the fork bed 125 for switching the third and fourth speeds, and the ball 131 is attached to each recess 130 by a spring (not shown).
is biased in the direction of fitting. As a result, a detent mechanism is configured, and the fork head 125 for switching between the third and fourth speeds, that is, the shift fork for switching between the third and fourth speeds 101, moves the selector sleeve 99 to the second left to shift the third speed. position for establishing (left position in Figure 8) and select sleeve 9
9 in the center to bring it to a neutral state (8th position)
(center position in the figure) and the select sleeve 99 to the second position.
It can be moved to the right in the diagram to establish the fourth gear (the right position in Figure 8).

Moreover, the fork head 12 for switching between 3rd and 4th speeds
5 is located at a position corresponding to the very low speed fork head 123 slidably supported on the first fork shaft 116, and the very low speed fork head 123
A notch 133 is provided in which the protrusion 132 of the third and fourth speed switching fork head 125 projects toward the first forkshaft 116, and the notch 133 extends along the axial direction of the first forkshaft 116. The length is extremely low speed fork head 123
This is determined to allow relative movement of the fork head 125 for switching between the third and fourth speeds.

The fifth speed fork head 126 is integrally provided with an arm 134 that extends toward the first fork shaft 116, and a cylindrical portion 135 for passing the first fork shaft 116 is provided at the tip of this arm 134. provided. The arm 134 is provided with a hole 136 extending between the first and second forkshafts 116, 120.
A pair of balls 138 and 139 are inserted into the ball 36 and are urged by a spring 137 in directions away from each other. First and second forkshaft 116,1
Recesses 140, 141 for fitting the balls 138, 139 are provided on the outer surface of the ball 20, and both balls 138, 139 fit into the recesses 140, 141.
41, the position of the fifth speed fork head 126 is maintained in a moderate manner. This state is a state in which the fifth speed switching synchronization mechanism 102 is inactive, and the connection state between the fifth speed gear train G5 and the input shaft 38 is released.

With the fifth speed switching synchronization mechanism 102 inactive, the fifth speed fork head 126
is prevented from moving to the right in FIG. 8 by the side wall of the transmission case 33, and can only move to the left in FIG. 8 in order to put the fifth speed switching synchronizing mechanism 102 into operation. That is, the end of the second forkshaft 120 on the transmission case 33 side is provided with a stepped portion 142 that can come into contact with the fifth speed fork head 126, so that when the second forkshaft 120 is moved to the left, , the fifth speed fork head 126 moves to the left in FIG. 8 while compressing the spring 137 so that the ball 138 escapes from the recess 140 and rides on the outer surface of the first fork shaft 116. Due to this movement, the fifth speed switching synchronization mechanism 102 is actuated, and the fifth speed gear train G5
is established. Furthermore, when the fifth speed switching synchronization mechanism 102 is operated, the spring 137 is compressed and exerts a large spring force, so that the second forkshaft 120 and the fifth speed fork head 126
When the second forkshaft 120 moves to the right, the fifth gear fork head 126 moves to the right and returns to the state shown in FIG. Synchronization mechanism 102
is inactive.

The reverse fork head 124 has a U-shaped tip.
An engaging arm 143 is provided which is formed in a letter shape and engages the tenth forkshaft 116, and this engaging arm 143 functions to prevent the second forkshaft 120 from rotating. Also fork head 1 for reversing
24 is integrally provided with an engaging pin 144 protrudingly provided, and the engaging pin 144 is engaged with an L-shaped through hole 145 provided in the reverse shift fork 109, as shown in FIG. Ru. The reverse shift fork 109 is integrally equipped with a support shaft 146 orthogonal to the axis of the second fork shaft 120.
This support shaft 146 is inserted into a support hole 147 bored in the shaft holder 115. Moreover, the support shaft 14
A ring 148 is fitted into the part protruding from the support hole 147 of 6, and the ring 148 and the support shaft 1
By inserting the pin 149 into 46 at right angles,
A reverse shift fork 109 is rotatably supported by the shaft holder 115 around the axis of a support shaft 146. Further, the through hole 145 has a parallel portion 145a parallel to the second fork shaft 120 when the reverse shift fork 109 is in the neutral position.
and an orthogonal portion 145b orthogonal to the second forkshaft 120 are arranged in a row in an L-shape, and the second
When the forkshaft 120 is in a neutral position where it does not move to the left or right as shown in FIG.
The engagement pin 144 is located at a bent portion of the through hole 145.

Furthermore, in order to moderate the rotational movement of the reverse shift fork 109, two recesses 151 are provided adjacent to each other on the side edge of the reverse shift fork 145, and the shaft holder 115 has two recesses 151 adjacent to each other. A ball 152 that can be fitted into the ball 151 is arranged so as to be biased by a spring in the fitting direction. A spring 153 is inserted into one recess 151 as shown in FIG.
In the fitted state, the engagement pin 144 is in the through hole 145.
When the second fork shaft 120 is moved to the right in FIG. 8, that is, in the direction of the arrow 154, the reverse shift fork 109 is moved clockwise in FIG. The ball 152 is fitted into the other recess 151. This clockwise rotation of the reverse shift fork 109 moves the idle gear 107 and establishes the reverse gear train Gr.

When canceling the establishment of the reverse gear train Gr, move the second forkshaft 120 to the left and
At this time, the reverse shift fork 109 is rotated counterclockwise to be in the neutral state as shown in FIG. 11. Furthermore, when the second forkshaft 120 is moved to the left from the state shown in FIG. The reverse shift fork 109 only moves along the vehicle and does not rotate.

The very low speed fork head 123 has an engagement groove 1.
56 is provided in this engagement groove 156,
A rotation preventing rod 157 whose base end is fixed to the shaft holder 115 and extends parallel to the first fork shaft 116 is engaged, thereby preventing the very low speed fork head 123 from rotating around the first fork shaft 116.

The third forkshaft 121 includes a connecting member 1
58 is fixed, and this connecting member 158 and the very low speed fork head 123 are connected by a lever 159. Lever 159 is basically L
A spherical fitting part 160 provided at one end of this lever 159 is fitted into a fitting hole 161 provided in the very low speed fork head 123. The connecting member 158 also has a connecting pin 16 that protrudes in a direction perpendicular to the third fork shaft 121.
2 is integrally provided, and this connecting pin 16
2 is fitted with a U-shaped fitting portion 163 provided at the other end of the lever 159. Moreover, the bent portion 159a of the lever 159 is pivotally supported by a pivot pin 164 that is orthogonal to the first and third forkshafts 116, 121.

With particular attention to FIG.
4, G5, and Gr, that is, between the third speed gear train G3 and the fourth speed gear train G4, the pivot pin 164 is fixed to the side wall of the transmission case 33. That is, the pivot pin 164 has, in order from one end thereof, a large-diameter head 165, a male threaded portion 166 that is screwed into the side wall of the mission case 33, and a bent portion 1 of the lever 159.
A small-diameter pivot portion 167 is provided to be inserted into a pivot hole 168 drilled in 59a, and is screwed onto the side wall of the mission case 33 from that side.

In this way, by swingably supporting the intermediate bent portion of one lever 159 by the pivot pin 164 serving as a pivot, the lever 159 performs a seesaw action. That is, when the very low speed fork head 123 is moved to the left in FIG. Moving to the right, the reduction gear train 78 of the sub-transmission mechanism 37 is established. In such a situation, the fork head 123 for extremely low speed
When the select sleeve 111 is moved to the right, the connecting member 158, the third fork shaft 121, and the very low speed shift fork 112 are moved to the left, and the select sleeve 111 is moved to the left.
moves to the left in FIG. 2, and the reduction gear train 78
The connection state between the auxiliary shaft 71 and the secondary shaft 71 is released.

In order to move left and right to the third forkshaft 121 in a controlled manner, a pair of depressions are provided at an interval in the axial direction on the outer surface of the end of the third forkshaft 121 on the transmission case 33 side. 169 are provided, and balls 170 that fit into these recesses 169 are biased by springs 171 in the direction of fitting into each recess 169.

As shown in FIG. 8, when the ball 170 is fitted into the right recess 169, the extremely low speed shift fork 112 is in a state where the extremely low speed switching synchronization mechanism 110 is inactive, When the third forkshaft 121 is moved to the right from this state and the ball 170 is fitted into the left recess 169, the very low speed switching synchronization mechanism 110 is activated.

The very low speed fork head 123, the first and second speed switching fork heads 122, the third and fourth speed switching fork heads 125, and the reverse fork head 124 each have a U-shaped locking part 172 for very low speeds, a first , a locking part 173 for switching to 2nd speed, a locking part 174 for switching to 3rd and 4th speeds, and a locking part 175 for switching to 5th speed and reverse, which are connected from the first forkshaft 116 to the second forkshaft 116. They are arranged in this order toward the shaft 120 side.

Referring to FIGS. 12 and 13 together, a cover 179 is fixed to the upper part of the clutch case 32 to define an operating chamber 178 that communicates with the inside of the transmission case 33. Selection of locking parts 172, 173, 174, 175,
Select and shift mechanism 180 for operation
will be placed.

To explain this select and shift mechanism 180 in detail, a shift piece shaft 181 extending in a direction orthogonal to each of the fork shafts 116, 120, 121 is fixedly disposed on the cover 179. A shift piece 183 is slidably and rotatably supported on this shift piece shaft 181 and is integrally provided with an engaging arm 182 that can selectively engage each of the locking portions 172, 173, 174, and 175. . This shift piece 183 has a rotation engagement groove 184 extending parallel to the shift piece shaft 181;
A sliding engagement groove 185 extending perpendicularly to the shift piece shaft 181 is provided.

A spherical end 188 of a shift arm 187 rotatably supported by the cover 179 via a shift shaft 186 is slidably fitted into the rotation engagement groove 184 . In addition, the sliding engagement groove 185 has a cover 1.
A pin-shaped end 191 of a select arm 190 rotatably supported by a select shaft 189 at
are slidably engaged. The shift shaft 186 and the select shaft 189 extend in a direction perpendicular to the shift piece shaft 181 and protrude from the cover 179, and the shift arm 187 and the select arm 190 are arranged substantially orthogonally in the working chamber 178 so that the shift shaft 189 extends in a direction perpendicular to the shift piece shaft 181. 186 and select axis 18
Fixed to 9. Further, on the outside of the cover 179, a shift lever 192 is fixed to the shift shaft 186, and a select lever 193 is fixed to the select shaft 189.

A shift wire 194 is attached to the shift lever 192.
The terminal end of the select wire 195 is connected to the select lever 193. These wires 194 and 195 perform a push-pull operation in response to the operation of a change lever (not shown), and the selection wire 195 performs a push-pull operation in response to displacing the change lever at the neutral position N. , the shift wire 194 moves the change lever to each shift position SL,...
, , R, performs a push/pull operation.

The shift piece shaft 181 has the shift piece 18
U-shaped interlock plate 19 sandwiching 3.
6 is slidably disposed. This interlock plate 196 is provided with a long groove 197 extending parallel to the shift piece shaft 181, and when a pin member 198 screwed onto the cover 179 engages with the long groove 197, the rotational movement of the interlock plate 196 is controlled. thwarted.

There are three depressions 20 at the tip of the shift arm 187.
1 are provided, and balls 202 that can fit into the recesses 201 are biased by a spring 203 housed within the cover 179 in the direction of fitting into each recess 201. As a result, the shift arm 187 can be rotated between three positions. Moreover, these three positions are determined by shift piece 1 according to the shift pattern shown in FIG.
83, each locking portion 172, 173, 174, 1
This corresponds to the position for shifting 75.

Each locking portion 1 is provided at the tip of the select arm 190.
A recess 204 extending in an arc shape centered on the shift shaft 186 is provided with a length corresponding to moving the shift piece 183 to select 72, 173, 174, 175. A spring 205 housed in the ball 179 causes the ball 106 to resiliently slide into contact. Further, an arm portion 207 is integrally provided on the select arm 190, and both ends of a torsion spring 208 surrounding the select shaft 189 extend on both sides of the arm portion 207. Both ends of the torsion spring 208 are engaged with locking pins 209 protruding from the cover 179, and the select arm 190 rotates to select a gear position by the rotation of the select shaft 189. At times, it exerts a spring force in the direction of returning the select arm 190 to its original position, and serves to give the driver a sense of operation when operating the change lever.

At a position adjacent to the select shaft 189 on the side where the shift piece 183 engages with the very low speed locking portion 172, a very low speed interlock plate 210 is attached to the cover 1 via a rotating shaft 211 parallel to the select shaft 189.
79 so as to be rotatable. This very low speed interlock plate 210 is rotatable between a position where it blocks movement of the select shaft 189 until selecting very low speed and a position where it is allowed, and moderates the rotational movement between these positions. A pair of recesses 212 are provided for this purpose. Also, on the cover 179 side, there are balls (not shown) that can fit into those recesses 212.
is biased by a spring in the direction of fitting into the recess 212,
Placed.

On the other hand, the select arm 190 is provided with a protrusion 213, and an extremely low speed interlock plate 210 is provided.
When the rotor is rotated to a position that prevents selection of extremely low speed, the protrusion 213 comes into contact with the extremely low speed interlock plate 210, and the rotational movement of the transmission is blocked. As a result, the shift piece 183 becomes unable to engage with the very low speed locking portion 172, and selection of the very low speed is prevented.

The rotation shaft 211 protrudes from the cover 179, and the rotation shaft 211 and the gear clutch mechanism 55 in the transfer 5 are connected to operate together. That is, as shown in FIG. 7, the swing shaft 61 of the gear clutch mechanism 55 is connected to the clutch case 32.
The protruding end 6 of this swing shaft 61 protrudes from the
A connecting lever 214 that is provided to protrude outward in the radial direction at 1a and a connecting lever 215 that is provided to protrude radially outward at the protruding end of the rotating shaft 211 are connected to each other via a connecting rod 216. Concatenated. Moreover, the connection mode is the gear clutch mechanism 5.
5 is in the cutoff state, the very low speed interlock plate 210 is rotated to a value that allows it to come into contact with the protrusion 213 of the select shaft 189, thereby blocking selection of the very low speed.

In the shift piece shaft 181, a step portion 217 facing the front end side is provided at the front end portion along the moving direction of the shift piece 183 toward the extremely low speed side, and a shift portion on the front end side of the step portion 217 is provided. A plate-shaped abutting collar 218 that can abut against the step portion 217 is slidably disposed on the piece shaft 181 . A malfunction prevention spring 219 is interposed between the abutting collar 218 and the cover 179, and the spring force of the spring 219 urges the abutting collar 218 toward the stepped portion 217.

The contact flange 218 is capable of contacting an interlock plate 196 that moves on the shift piece shaft 181 integrally with the shift piece 183, and when the abutment flange 218 is in contact with the stepped portion 217, the shift piece 183 When the interlock plate 196 is in the position to select the first speed or the second speed, the contact flange 218
It is set so that it comes into contact with. Therefore, when moving the shift piece 183 from the first speed or second speed selection position to the very low speed selection position, the abutment collar 218 is pressed and moved against the spring force of the malfunction prevention spring 219. It is necessary to do so.

A breather hole 220 is provided in the shift shaft 186 between the working chamber 178 and the outside, and a conduit 222 is further connected to a small diameter connecting pipe 221 connected to the outer end of the breather hole 220. .

Next, the operation of this embodiment will be explained. By operating the change lever according to the shift pattern shown in FIG.
5 and the shift wire 194 perform a push-pull operation, and the select and shift mechanism 180 operates accordingly to establish a desired gear train in the transmission 3. That is, when the first gear is set, the shift piece 183 is moved toward the shift piece shaft 1.
81 is fried and the locking part 1 for switching between 1st and 2nd speeds is installed.
73, and then the shift piece 183
By rotating clockwise in Figure 3, the first and second
The speed switching locking portion 173, that is, the first and second speed switching fork head 122 and the first and second speed switching shift fork 98 move to the left side in FIG.
A speed gear train G1 is established. Furthermore, when changing to the second gear, the shift piece 183 may be rotated counterclockwise in FIG. Second speed gear train G2 is established.

When selecting the third and fourth gears, the shift piece 183 rotates at a position corresponding to the third and fourth gear switching locking portions 174.
Third speed gear train G3 and fourth speed gear train G4 are selectively established. In addition, when selecting the fifth gear and the reverse gear, the shift piece 183 selects the fifth gear and the reverse gear.
By rotating at a position corresponding to the backward switching locking portion 175, the fifth speed gear train G5 and the reverse gear train Gr are selectively established.

When selecting extremely low speed, shift piece 183
engages with the very low speed locking part 172 and rotates clockwise in FIG. 13, so that the very low speed fork head 123 slides to the left in FIG. However, lever 15
9 and the continuous member 158, the third forkshaft 121 and the very low speed forkshaft 112 are moved to the right, and the sleeve 11
1 moves to the right side in FIG. 2 and the reduction gear train 78 is established. Accordingly, the driving force of the input shaft 38 is transmitted to the output shaft 39 via the sub-transmission mechanism 37, and the output of the output shaft 39 is transmitted to the transfer 5 at extremely low speed.

Moreover, when the gear clutch mechanism 55 is in the disconnected state, the select/shift mechanism 180 is in a position where the protrusion 213 of the select arm 190 can engage with the very low speed interlock plate 210, as shown by the solid line in FIG. Yes, select axis 18
9 connects the shift piece 183 to the very low speed locking part 172
It is prevented from rotating to the position where it is engaged with. Therefore, extremely low speed can be selected by
This applies only to all-wheel drive with the gear clutch mechanism 55 in the connected state.

In such a transmission 3, the first forkshaft 116 and the second forkshaft 120
is provided in the conventional main transmission mechanism 36, and when attaching the sub-transmission mechanism 37, it is only necessary to newly add the third forkshaft 121. Therefore, each shift fork 98, 101, 104, 109 of the main transmission mechanism 36
and first and second forkshafts 116,
There is no need to change the arrangement of 120, and the configuration is simplified.

Moreover, the shift fork 98 for switching between 1st and 2nd speeds
Since the very low speed fork head 125 is slidably supported on the first fork shaft 116 that supports the As shown in Figure 6, it is possible to form a shift pattern in which the very low speed position SL is placed adjacent to the first speed position, and each shift position is arranged in the order of the reduction ratio, making it easier for the driver to The shift operation feeling is improved.

Further, since the shift fork 112 for extremely low speed switching is operated by the see-saw movement of the lever 159, there are the following advantages compared to using a long shift fork. That is,
The bending rigidity of the shift fork 112 for extremely low speed switching can be small, and the outer shift fork 112
can be formed compactly, and the bending rigidity of the first forkshaft 116 can also be reduced. Furthermore, since the offset load on the third fork shaft 121 can be reduced, the sliding resistance of the very low speed switching shift fork 112 is reduced, and the shift fork 112 can operate smoothly.

C. Effects of the Invention As described above, according to the present invention, there is provided a gear train with a plurality of gears that can be selectively established between the input shaft and the output shaft, and the gear train can be selectively established. In order to establish a main transmission mechanism, a main transmission mechanism has a plurality of synchronizing mechanisms driven by a shift fork for changing gears supported by a plurality of fork shafts,
A sub-transmission having a reduction gear train for achieving a speed even lower than the lowest gear of the main transmission mechanism, and a synchronization mechanism for extremely low speed switching driven by a shift fork for extremely low speed switching to establish the reduction gear train. In a vehicle transmission equipped with a mechanism, a shift fork for extremely low speed switching is integrally supported, and a shift fork is moved between a first position in which the shift fork is activated and a second position in which the shift fork is deactivated. A sliding very low speed forkshaft is supported on the transmission case parallel to and spaced apart from each forkshaft of the main transmission mechanism, and is used for switching to establish a gear train for the lowest gear of the main transmission mechanism. The fork shaft supporting the shift fork supports an extremely low speed fork head that can slide on the fork shaft in response to a shift operation to extremely low speed;
In order to move the extremely low-speed fork shaft between the first and second positions in conjunction with the extremely low-speed fork head, a lever is provided with an intermediate portion swingably supported on the mission case via a pivot. One end is connected to the very low speed fork head, and the other end is connected to the very low speed fork shaft, so that the existing main transmission mechanism can be connected to the very low speed fork head, the very low speed fork shaft, and the very low speed fork shaft. The shift operation system for the auxiliary transmission mechanism can be easily added by adding only a few parts, such as a single lever between the fork head and the shaft. No major layout changes are required, and this can greatly contribute to cost reduction and improved assembly efficiency. Moreover, by slidably supporting the very low speed fork head on the existing fork shaft that supports the shift fork for establishing the lowest gear of the main transmission mechanism, the support structure of the low speed fork head is simplified. In addition, it is possible to obtain a rational shift pattern in which the extremely low speed position is located adjacent to the lowest speed change position of the acid transmission mechanism, and the shift feeling is also good.

In addition, particularly in relation to the fact that the fork shaft of the main transmission mechanism that slidably supports the fork head for extremely low speed and the fork shaft for extremely low speed that integrates the shift fork for extremely low speed switching are arranged parallel to each other, The sliding displacement of the fork head for extremely low speeds can be easily converted into the sliding displacement of the fork shaft for extremely low speeds along the sliding direction by a simple see-saw movement of the lever around the pivot axis. The movement of the shift operation system between the fork head and the shift fork for extremely constant speed switching is greatly simplified, and the looseness of each part of the shift operation system can be minimized, making it possible to easily shift to extremely low gears. Shift operations can always be performed quickly and accurately. Moreover, by simply selecting the pivot position and lever ratio of the one lever as appropriate, the transmission mode of the shift operation system between the very low speed fork head and the very low speed switching shift fork can be changed in various ways. Together with the effect of greatly simplifying the movement of the shift operation system itself, the degree of freedom in designing the transmission can be greatly enhanced.

Furthermore, by the see-saw action of the single lever mentioned above, the sliding displacement of the very low speed fork head is converted into the displacement of the very low speed fork shaft and eventually the shift fork, so this lever can be omitted and the shift fork for very low speed switching is The bending rigidity of the shift fork can be kept low compared to a shift fork that has a long structure, making it lighter and more compact, and the sliding resistance of the fork shaft for very low speeds can be reduced. This makes it possible to shift to an extremely low gear even more easily.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a schematic diagram of the entire transmission system of a vehicle equipped with the transmission of the present invention, FIG. 2 is a longitudinal developed view of the transmission including the transmission, and FIG. 4 is an enlarged longitudinal sectional view of the auxiliary transmission mechanism, FIG. 4 is a sectional view taken along the line -- in FIG. 3, FIG. Fig. 7 is a cross-sectional side view taken in the direction of the arrow in Fig. 2, Fig. 8 is a plan view showing the arrangement of each shift fork, Fig. 9 is a perspective view showing the operating system of each shift fork, and Fig. 10 is a clutch of the shaft holder. Vertical side view showing how it is attached to the case, 1st
Figure 1 is a plan view showing how the reverse shift fork is attached to the shaft holder, Figure 12 is the select,
A cutaway plan view of the shift mechanism, and FIG. 13 is a cross-sectional view taken along the - line in FIG. 12. 3...Transmission, 33...Mission case, 3
6...Main transmission mechanism, 37...Sub-transmission mechanism, 38...
...Input shaft, 39...Output shaft, 78...Reduction gear train, 97,100,102...Synchronization mechanism, 98,
101, 104...Shift fork, 110...
Synchronous mechanism for extremely low speed switching, 112... Shift fork for extremely low speed switching, 116, 120, 121... Fork shaft, 123... Fork head for extremely low speed, 159... Lever, 164... Pivot pin,
G1 to G5, Gr...Gear train.

Claims (1)

[Claims] 1. A gear train G with a plurality of selectively establishable gears provided between an input shaft 38 and an output shaft 39
1 to G5, and their gear trains G1 to G5.
In order to selectively establish G5, a main transmission mechanism 36 includes a plurality of synchronizing mechanisms 97, 100, 102 driven by shift forks 98, 101, 104 for gear change supported by a plurality of fork shafts 116, 120. and a reduction gear train 78 for achieving a lower speed than the lowest gear of the main transmission mechanism 36.
and a synchronizing mechanism 110 for very low speed switching driven by a shift fork 112 for very low speed switching to establish the reduction gear train 78.
7, which integrally supports the very low speed switching shift fork 112 and has a first position in which the shift fork 112 is actuated and a second position in which the shift fork 112 is deactivated. An extremely low-speed forkshaft 121 that can slide between the forkshafts 116 and 120 of the main transmission mechanism 36 is supported by the transmission case 33 parallel to and spaced apart from the forkshafts 116 and 120 of the main transmission mechanism 36,
The fork shaft 116 that supports the switching shift fork 98 for establishing the lowest gear train G1 of the main transmission mechanism 36 has a fork shaft 116 that can slide on the fork shaft 116 in response to a shift operation to an extremely low speed. An extremely low speed fork head 123 is supported, and a shaft 164 is connected to the mission case 33 in order to move the extremely low speed fork shaft 121 between the first and second positions in conjunction with the extremely low speed fork head 123. A vehicle transmission characterized in that one end of a single lever 159 whose intermediate portion is swingably supported is connected to the very low speed fork head 123 and the other end to the very low speed fork shaft 121. Machine. 2. The vehicle transmission according to claim 1, wherein the remaining switching shift forks in the main transmission mechanism are commonly supported by a fork shaft different from the fork shaft.