GB2093539A

GB2093539A - Conjoint control of change-speed gear and transfer unit

Info

Publication number: GB2093539A
Application number: GB8105449A
Authority: GB
Original assignee: Fuji Jukogyo KK; Fuji Heavy Industries Ltd
Current assignee: Subaru Corp
Priority date: 1981-02-20
Filing date: 1981-02-20
Publication date: 1982-09-02
Also published as: GB2093539B

Abstract

In a four-wheel drive motor vehicle comprising a sub-transmission adapted to transmit the power of the engine to a main transmission and means for transmitting the output of the main transmission to the front axle F and selectively to the rear axle, a shift rail 49 changes the ratio in the sub-transmission, an actuating rail 50 is slidably provided in parallel with the shift rail 49 and carries a shift fork 59 for selecting between two and four wheel drive and a fixed rail 51 is provided in parallel with the shift rail 50 and actuating rail 49. An arm 57 is slidably mounted on the actuating rail, shift rail and fixed rail. Interlock means 64, 65 cause the actuating rail and shift fork to move together within a first moving range of the actuating rail, while second interlock means 64 cause the actuating rail and shift rail to move together within a second moving range of the actuating rail and ensure that at one end of the first range, the front wheel driving transmission is engaged, at the middle position the high speed four wheel driving transmission is engaged, and at the other end of the second moving range the low speed four wheel driving transmission is engaged. <IMAGE>

Description

SPECIFICATION Manipulation device for a transmission apparatus The present invention relates to a manipulation device or transmission selection mechanism for the transmission of a four-wheel drive motor vehicle, which can also be driven selectively by the front wheels only or the rear wheels only. More particularly, the invention relates to a transmission apparatus having a sub-transmission combined with a main transmission and a clutch device for disconnecting the transmission of the power to either of the front wheels or the rear wheels, whereby the car may be driven in a high power four wheel driving range and an economical four wheel driving range.

Such an apparatus including the sub-transmission and the clutch device must be provided with a shift lever for manipulating the sub-transmission and another shift lever for manipulating the clutch device. This increases difficulties in manipulation of the transmissions and clutch device.

In order to overcome these problems, there is disclosed in U.S. Patent No. 4,170,273 a transmission apparatus for a four-wheel drive motor vehicle in which a sub-transmission and clutch device can be manipulated by a single shift lever to change the transmission speed of the sub-transmission and to convert the four-wheel drive into two-wheel drive through the front wheels.

The manipulation device for the transmission apparatus comprises a shift rod axially slidably provided for shifting a clutch means for the subtransmission, an actuating rod slidably provided in parallel with the shift rod, a shift lever connected to the actuating rod, a shift fork slidably mounted on the actuating rod and engaged with the clutch device, a first engaging means for causing the actuating rod and shift fork to come into the fixed engagement relation to each other within a first moving range of the shift lever, second engaging means provided for causing the actuating rod and shift rod to come into fixed engagement relation to each other within a second moving range of the shift lever adjacent the first moving range, and a stopper provided on a guide plate for stopping the shift rod and shift fork.

In such a device, the stopper secured to the guide plate is subjected to shifting forces through the shift rod and shift fork. As a result, the guide plate and cover thereof are liable to be damaged by the forces.

Deformation of the cover causes the malfunction of the apparatus and/or oil leakage.

An object of the present invention is to provide a manipulation device for a transmission apparatus capable of having a high stiffness which ensures a reliable operation.

In accordance with the present invention, the manipulation apparatus comprises a shift rail axially slidably provided for shifting said clutch means in said sub-transmission, an actuating rail slidably provided in parallel with said shift rail, a fixed rail fixedly provided in parallel with said shift rail and actuating rail, a shift lever connected to said actuating rail, a shift fork slidably mounted on said actuating rail and fixed rail, said shift fork is connected to said clutch device, an arm secured to said shift rail and slidably engaged with said actuating rail and fixed rail, first interlock means provided between said actuating rail and shift fork and fixed rail for causing said actuating rail and shift fork to come into fixed engagement relation to each other within a first moving range of said actuating rail, thereby to shift the shift fork by manipulating said shift lever, and for causing said shift fork and fixed rail to engage with each other within a second moving range of said actuating rail, second interlock means provided between said actuating rail and arm to come into fixed engagement relation to each other within the second moving range of said actuating rail adjacent said first moving range thereby to shift said shift rail, and for causing said arm and fixed rail to engage with each other within said first moving range of said actuating rail, and a snap ring provided between said shift fork and arm on said actuating rail for moving said shift fork and arm.

The invention will be more readily understood by way of example from the following description of a motor vehicle transmission in accordance therewith, reference being made to the accompanying drawings, in which: Figure la is a sectional view showing a left half of a vehicle transmission, Figure 1 b is a sectional view showing a right half of the transmission, Figure 2 is a sectional view taken along the line ll-ll of Figure 1a, Figure 3 is a sectional view taken along the line Ill-Ill of Figure 1a, Figure 4 is a sectional view taken along the line IV-IV of Figure 1 b, Figures 5a and 5b are illustrations for showing the operation of transmission manipulation device.

Referring to the drawings, numeral 1 designates a flywheel secured to the end of a crankshaft of the engine which is longitudinally disposed in the front portion of car. A first main drive shaft 3 in alignment with the crankshaft is rotatably supported and a clutch device 2 is provided on the first main drive shaft to engage with the flywheel 1 for transmitting the power of the engine. A 2-speed sub-transmission S is positioned above the front axle F to transmit the power of the engine to a second main drive shaft 10.

The sub-transmission S, as shown in Figure 2, comprises a gear 5 formed on the first main drive shaft 3, counter gears 7 and 8 rotatably mounted on a counter shaft 6, a gear 11 rotatably mounted on the second main drive shaft 10, and an inertia lock type syncromesh mechanism 12 as a clutch means for the sub-transmission mounted on splines on the second main drive shaft 10; when the clutch means are engaged there is direct drive between shafts 3 and 10. The gears 5 and 11 mesh with the gears 7 and 8 respectively.

The second main drive shaft 10 is in alignment with the first main drive shaft 3 and extends into a transmission case 13 of a 4-speed main transmission M, being rotatably supported by bearings 14 and 15.

The main transmission M comprises a lower 2-speed transmission device and a higher 2-speed transmis sion device. The lower 2-speed transmission device comprises gears 16 and 17 formed on the second main drive shaft 10, gears 18 and 19 rotatably mounted on a third main drive shaft 21 and engaged with the gears 16 and 17 respectively, and a lower speed stage syncromesh mechanism 20 splined on the shaft 21 between the gears 18 and 19. The higher 2-speed transmission device comprises gears 22 and 23 rotatably mounted on the second main drive shaft 10, a higher speed stage syncromesh 24 splined on the shaft 10 between the gears 22 and 23, and integral gears 25 and 26 keyed on the third main drive shaft 21 and engaged with the gears 22 and 23 respectively. It should be noted that the reverse gear mechanism is not shown in the drawings.

The third main drive shaft 21 is rotatably supported by bearings 27 and 28 and provided with a hypoid pinion 30 formed at the front end thereof.

The hypoid pinion 30 meshes with a ring gear 31 of a final reduction gear device mechanism T. The final reduction gear device is positioned beneath the sub-transmission S in the space between the clutch device 2 and the main transmission M, and adapted to transmit the output of the third main drive shaft 21 to the front wheels through the front axle F. The rear end of the third main drive shaft 21 extends out of the transmission case 13, on which a gear 37 (Figure 1 b) is fixed.

On the rear end of the transmission case 13 there is a housing 33 in which a rear wheel drive shaft 34 is rotatably supported by bearings 35 and 36. On the rear wheel drive shaft 34 is rotatably mounted a gear 38 which engages the gear 37. A rear wheel drive syncromesh mechanism 40 of a clutch device N for four wheel drive is splined on the rear wheel drive shaft. The rear wheel drive shaft 34 is connected to a rear axle through a propellor shaft (not shown).

The device for manipulating the clutch means in the sub-transmission S and for coupling the third main drive shaft 21 to the rear wheel drive shaft 34 will now be described. In the sub-transmission S, a shift fork 46 (Figure 3) is secured to a shaft 44 with a pin 45 (Figure 1a) and opposite ends of the shift fork are slidably engaged with a circumferential groove 42 of a sleeve 41 which in known manner is a part of the syncromesh mechanism 12. A lever 47 on shaft 44 is pivotally connected to a link 48 of which the rear end is connected to a shift rail 49 (Figure 4) through a connecting member 53. The shift rail 49 is slidably supported in the housing 33. An actuating rail 50 is slidably mounted in housing 33 and a fixed rail 51 is secured in the housing 33 by a pin 52, with rails being parallel to shift rail 49.The rear end of the actuating rail 50 is connected to a shift lever 54 (Figure 1 b) by a ball joint. The shift lever 54 is pivotally mounted on a bracket 55 by a pin 56.

As shown in Figure 1 b, the shift lever 54 can be moved to a front wheel driving position FF, a high speed fourwheel driving position 4WDH our a low speed four wheel driving position 4WDL, the actuating rail 50 may be moved to three corresponding positions.

An arm 57 (Figure 4) is secured to the shift rail 49 by a pin 58 and is slidably engaged with the rails 50 and 51. A shift fork 59 is slidably engaged with the actuating rail 50 and fixed rail 51. An end of the shift fork 59 is engaged with a groove 61 of a sleeve 60 of the syncromesh mechanism 40, as shown in Figure 1 b. A snap ring 62 is engaged with the actuating rail 50 between the arm 57 and the shift fork 59 so as to move the arm and fork. A snap ring 63 is secured to the fixed rail 51 so as to restrict forward movement of the arm 57.

A first interlock means 64 is provided between the actuating rails 50 and 51. The interlock means comprises an interlock pin 69 slidably provided in the arm 57, a notch 70 of the rail 50, and a notch 71 on the rail 51. A second interlock means 65 is also provided between the rails 50 and 51. The second interlock means comprises an interlock pin 72 slidably provided in the shift fork 59, a notch 73 on the rail 50 and a notch 74 on the rail 51. A ball lock means 66 comprises notches 75 and 76 on the rail 49 and a ball 77 urged against the rail 49 by a spring 78 in the housing 33. A ball lock means 67 comprises a notch 79 on the rail 50, and a ball 80 and spring 81 in the housing 33. A ball lock means 68 comprises notches 82 and 83 on the rail 51, and ball 82 and spring 85 in the shift fork 59. A cover 86 is secured to the housing 33 by bolts 87 as shown in Figure 1 b.

In operation, for front wheel drive, the shift lever 54 is shifted to the front wheel driving position FF in Figure 1 b. The actuating rail 50 is positioned in the extreme right position (Figure 4), whereby the shift fork 59 is located in the right hand position by the snap ring 62, where the pin 72 engages the notch 73 of the actuating rail 50 and the lock ball 84 engages the notch 82 of the fixed rail 51 as shown. In this position, the sleeve 60 of the syncromesh mechanism 40 is shifted to the right position, so that the clutch device of the mechanism does not engage the gear 38 and the power of the engine is not transmitted to the rear wheels. The arm 57 and shift rail 49 are also in their right hand positions, with the ball 77 engaged with notch 75 of the shift rail 49 to locate the rail.

In this position, the link 48 is in its right hand position, so that the shift fork 46 is actuated to shift the sleeve 41 of the syncromesh 12 of the subtransmission S in the left direction to couple the clutch device between the gear 5 and the syncromesh 12 and to provide direct drive between shafts 3 and 10.

Thus, the power of the engine is transmitted through the clutch device 2, first main drive shaft 3, gear 5 and sleeve 41 of syncromesh mechanism 12 to the second main drive shaft 10 without reduction by the sub-transmission S. The 4-speed main transmission M transmits the rotation of second main drive shaft 10 to the third main drive shaft 21. More particularly, if the syncromesh mechanism 20 is actuated by manipulating a shift lever (not shown) to couple the clutch device between the syncromesh mechanism and the gear 18, the third main drive shaft 21 is rotated at the lowest first speed. If the clutch device between the syncromesh mechanism and the gear 19 is engaged, the drive shaft 21 rotates at the second speed.Further, engagement of the clutch device between the syncromesh mechanism 24 and the gear 22 will produce the third speed of the drive shaft 21, and engagement of the clutch device between the syncromesh mechanism and the gear 23 causes the fourth speed rotation of the drive shaft 21. The output of the drive shaft 21 is transmitted to the front axle through the gears 30 and 31 to drive the front wheels. On the other hand, since the clutch device N is not in engagement position with the gear 38, the rear wheels are not driven. Thus, only the front wheels are driven in the higher speed range without the speed reduction of the sub-transmission S.

When the shift lever 54 is moved to the high speed four-wheel driving position 4WHD in Figure 1 b, the actuating rail 50 is shifted to the left as far as the intermediate position shown in Figure 5a. Since the pin 72 engages the notch 73 of the actuating rail 50, the shift fork 59 is also shifted in the left direction together with the rail 50. The arm 57 is stopped by the engagement between the pin 69 and notch 71 of the interlock means 64. When the shift fork 59 reaches the position of Figure 5a, the ball 80 engages the notch 79 and the ball 84 engages the notch 83.

Thus, the shift fork is stopped at the middle position.

Thus, the sleeve 60 of the syncromesh mechanism 40 is shifted to the left to engage the gear 38. Accord ingly, the shaft 34 is rotated through the third main drive shaft 21, gears 37 and 38 and sleeve 60. Since the shift rail 49 is not moved, the sub-transmission S is still in the higher speed coupling stage. Thus, the front and rear wheels are driven at the higher speed range without speed reduction by the subtransmission S.

When the shift lever 54 is moved to the low speed four-wheel driving position 4WDL, the actuating rail 50 is shifted to its extreme left hand position as shown in Figure 5b. In this operation, the fork 59 stays in the position of Figure 5a, the pin 72 is moved by the slant of the notch 73 to engage the notch 74.

The arm 57 is moved by the snap ring 62 whereby the pin 69 is shifted out of notch 71 and into engagement with notch 70. Thus, the shift rail 49 is moved together with the arm 57 and locked by engagement of the lock ball 77 with the notch 76 in the left hand position. The movement of the shift rail 49 causes counter-clockwise rotation of the lever 47 and shift fork 46 through the link 48 thereby to move the sleeve 41 of the syncromesh mechanism 12 to bring about the engagement between the syncromesh mechanism and the gear 11. Therefore, the rotation of the first main drive shaft 3 is transmitted to the second main drive shaft 10 with the reduction of gears 5,7,8 and 11 and the front and rear wheels are driven at the lower speed range.

When the shift lever 54 is moved from the position 4WDL to the position 4WDH, the arm 57 is moved together with the actuating rail 50 to shift the shift rail 49 to the middle position. When the shift lever 54 is further moved to the position FF, the shift fork 59 is moved to the position FF by the snap ring 62.

From the foregoing it will be understood that the sub-transmission and clutch device for four wheel drive may be manipulated by one shift lever to change the sub-transmission and to convert into the four wheel drive. The manipulation device is provided with a fixed rail 51 for interlocking the arm 57 and shift fork 59. Thus, stiffness of the device is increased and deformation of members, such as a guide plate or housing may be prevented, so that reliability of the operation may be ensured.

In the above mentioned embodiment, although the front wheels are the main drive wheels and the rear wheels are sub-drive wheels, it is possible to modify the arrangement to have the rear wheels as the main drive wheels and the front wheels as the sub-drive means.

Further, since the actuating rail is locked by two ball lock means at the middle position between the first and second drive range, the locking effect is ensured and the manipulation feel of the shift lever is improved.

Claims

1. A manipulation device for the transmission of a vehicle having a first main drive shaft connected to a crankshaft of an engine through a clutch means, a sub-transmission provided adjacent to said first main drive shaft, a second main drive shaft provided adjacent said sub-transmission, said subtransmission including reduction gearing and a clutch means manually operable to select the trans mitting speeds for transmitting the output of said first main drive shaft to said second main drive shaft, a third main drive shaft provided in parallel with said second main drive shaft, a main transmission provided on said second and third main drive shafts, means for transmitting the output of said third main drive shaft to the front axle and to the rear axle, and a clutch device provided in said meansfortransmitting the output of said third main drive shaft for selectively connecting or disconnecting the transmission of the output to either of the front or rear axle; the manipulation device comprising a shift rail axially slidably provided for shifting said clutch means in said sub-transmission, and actuating rail slidably provided in parallel with said shift rail, a fixed rail fixedly provided in parallel with said shift rail and actuating rail, a shift lever connected to said actuating rail, a shift fork slidably mounted on said actuating rail and fixed rail, said shift fork being connected to said clutch device, an arm secured to said shift rail and slidably engaged with said actuating rail and fixed rail, first interlock means provided between said actuating rail and shift fork and fixed rail for causing said actuating rail and shift fork to come into fixed engagement relation to each other within a first moving range of said actuating rail, thereby to shift the shift fork by manipulating said shift lever, and for causing said shift fork and shift rail to engage with each other within a second moving range of said actuating rail, second interlock means provided between said actuating rail and arm and fixed rail for causing said actuating rail and arm to come into fixed engagement relation to each other within the second moving range of said actuating rail adjacent said first moving range thereby to shift said shift rail, and for causing said arm and fixed rail to engage with each other within said first moving range of said actuating rail, and a snap ring provided between said shift fork and arm on said actuating rail for moving said shift fork and arm.

2. A manipulation device for a transmission apparatus in accordance with claim 1 wherein each of said first and second interlock means comprises a pin radially slidably provided to achieve said fixed engagement relation, and notches each of which having slants for retracting said pin by axial movement of said actuating rail.

3. A manipulation device for a transmission apparatus in accordance with claim 1 furthercom- prising ball lock means for locking said actuating rail and shift rail at end positions.

4. A manipulation device for a transmission apparatus in accordance with claim 3 wherein said ball lock means are provided between said shift rail and a supporting member thereof, between said actuating rail and a supporting memberthereof, and between said fixed rail and said shift fork, whereby said actuating rail is locked by two ball lock means at the middle position between said first and second moving ranges.

5. A manipulation device for the transmission of a vehicle, substantially as herein described with reference to the accompanying drawings.