JPH0653461B2 - Vehicle transmission structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention provides an input shaft for transmitting power from an engine in a state of penetrating in a front-rear direction with respect to a casing, and the power transmitted to the input shaft is changed in speed. A continuously variable transmission including an output shaft that is taken out and taken out from the casing is mounted on the front surface of the upper part of the mission case, and the power from the output shaft is transmitted to a traveling speed change mechanism in the mission case. The present invention relates to a transmission structure of a vehicle configured to be transmitted to front and rear wheels via a drive shaft, and to transmit power from the input shaft to an external power take-off shaft via an external power transmission mechanism in a mission case.

[Conventional technology]

As a vehicle with a transmission structure as described in the introduction,
As shown in JP-A-54-104125, an agricultural tractor can be cited as an example. In the conventional agricultural tractor, as shown in the reference, the input shaft and the output shaft of the continuously variable transmission are provided. Determine the posture of the casing so that they are up and down respectively,
The continuously variable transmission is mounted on the front surface of the upper part of the mission case, and the external power transmission mechanism and the traveling transmission mechanism are respectively provided between the transmission shafts arranged in a vertically positioned relationship with respect to the inside of the transmission case. They are arranged in a front-rear relationship.

[Problems to be solved by the invention]

Further, in the mission case of the above-mentioned reference, the power system for the front wheels from the front end of the output shaft of the continuously variable transmission is obtained.
When attempting to transmit the power changed in the mission case to the front wheels, the output shaft for the front wheels must be installed at a level below the casing of the continuously variable transmission, which increases the size of the mission case in the vertical direction. Cheap.

Further, if the external power transmission mechanism and the traveling transmission mechanism are arranged in the front and rear as in the above-mentioned reference, there is a limit even if an attempt is made to reduce the front-rear dimension of the transmission case, and the continuously variable transmission is If the casing is in the vertically long posture as in the above-mentioned reference, there is a limit to the reduction of the front-rear dimension of the mission case.For example, the mission case is connected to the rear part of the tractor frame including the frame, If a step is formed above the frame where it is located, even if an attempt is made to flatten the foot of the driver while the step is maintained at a low level, the stepless transmission or the mission case will be obstructed and the mission case Even if an attempt is made to lower the level of the driver's seat located above the vehicle, the mission case will hinder the improvement of the level in each case. There is.

An object of the present invention is to rationally modify the mission case configured as described above to reduce the front-rear dimension and the vertical dimension of the mission case as much as possible, and to prevent the reduction of the rear wheel. There is a point that the deceleration shortage in the case of downsizing the differential device is solved without increasing the vehicle height.

[Means for solving problems]

A feature of the present invention is that, in the vehicle transmission structure having the above-mentioned configuration, the input shaft and the output shaft are arranged in parallel in a lateral direction, and the drive side shaft of the traveling speed change mechanism is concentrically arranged with the output shaft downward. The driven side shafts of the traveling speed change mechanism are respectively arranged, the drive side shafts of the external power speed change mechanism are arranged concentrically with the input shaft, and the driven side shafts of the external power speed change mechanism are respectively arranged below. The drive shaft is provided with a gear speed reduction mechanism that reduces the speed on the rotation axis of the drive shaft that transmits the power from the traveling speed change mechanism to the rear wheels via a differential device. Is as follows.

[Work]

When the above features are configured as shown in, for example, FIGS. 1 to 3, the input shaft (20) and the output shaft (21) of the continuously variable transmission (4) are placed in a horizontally long posture in which the input shaft (20) and the output shaft (21) are parallel to each other in the lateral direction. The transmission (4) is attached to the mission case (5), and the transmission mechanism (25) for external power is provided below the input shaft (20) and the output shaft (21), which are arranged in parallel in the left-right direction. Since the speed change mechanism (35) for traveling is located, that is, the two speed change mechanisms (25), (35) are arranged in parallel below the input shaft (20) and the output shaft (21) in the parallel state. Therefore, the front wheel drive shaft (7) for the front wheel (8) can be arranged at a level close to the upper surface of the mission case (5) without being obstructed by the casing of the continuously variable transmission (4), and the mission case (5) The vertical size of the transmission case can be reduced, and the longitudinal size of the transmission case (5) can be reduced without being hindered by the arrangement of the two types of transmissions (25) and (35).

Further, even when the differential gear (36) for the rear wheel (11) is downsized, the gear reduction mechanism (39) moves from the differential gear (36) to the rear wheel (11).
The drive shaft (12) that is transmitted to the vehicle will be decelerated by the coaxial axis.

〔The invention's effect〕

Therefore, the mounting posture of the continuously variable transmission and the rational arrangement of the external power transmission mechanism and the traveling transmission mechanism can reduce the front-rear dimension and the vertical dimension of the transmission case, and the differential device can be downsized. As a result, sufficient deceleration can be achieved without increasing the vehicle height.

Particularly, in the present invention, by applying to a mission case of an agricultural tractor comprising a frame, the foot of the driver is flattened without increasing the step level, and the level of the driver's seat is reduced without lowering the vehicle height. Can be lowered.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 4, an engine (2) and a main clutch (3) are provided in front of a pair of left and right body frames (1), and a hydrostatic continuously variable transmission is provided at the rear of the body frame (1). (4) is equipped with a mission case (5) mounted on its front surface, and a transmission shaft (6) for transmitting the power from the main clutch (3) to the continuously variable transmission (4) is provided. It is equipped with an intermediate shaft (10) that transmits power from the front wheel drive shaft (7) projecting to the front of the vehicle to the differential device (9) of the front wheel (8), and further, the mission case (5).
Drive shafts (12) for the rear wheels (11) are provided on both side surfaces of the vehicle to configure a traveling transmission system of an agricultural tractor as an example of a vehicle.

The agricultural tractor has a flat step (13) in the center of the car body.
Is installed between the left and right rear fenders (14).
5) is provided, an external power take-off shaft (16) is provided on the rear surface of the mission case (5), and a mid mount drive shaft (17) is provided on the lower part of the mission case (5) so as to project forward. A hydraulic cylinder (19) including a pair of left and right lift arms (18) is attached to the upper surface of the case (5), and the transmission system inside the mission case (5) is arranged as follows. There is.

That is, as shown in FIGS. 1 and 3, the continuously variable transmission (4) is an input shaft to which the power from the transmission shaft (6) is transmitted.
(20) is provided so as to penetrate the casing of the device (4) in the front-rear direction, and the output shaft (21) for extracting the shifting power is juxtaposed in the left-right direction with respect to the input shaft (20), and from the casing. The power from the rear end of the input shaft (20) is transmitted to the first shaft (23) via the hydraulic clutch (22), and the power from the first shaft (23) is provided so as to project rearward. , A gear type external power transmission mechanism (25) arranged between the second shaft (24) located below the input shaft (20) in a front view as shown in FIG. After that, it is transmitted to the third shaft (27) coaxially arranged with the input shaft (20) via the gear transmission mechanism (26), and further transmitted to the second shaft (24) via the gear reduction mechanism (28). ) Is transmitted to the external power take-off shaft (16) arranged coaxially.

Also, the mid mount drive shaft (17) is provided below the first shaft (23).
The position of the first axis (2
A gear (29) attached to 3), a gear (30) idly supported on the second shaft (24), a gear (31) idly supported on the drive shaft (17),
And a clutch (32) between the gear (31) and the drive shaft (17)
The power from the first shaft (23) is transmitted via each of them.

The power from the output shaft (21) is transmitted to the fourth shaft (33) connected to the output shaft (21), and the power from the fourth shaft (33) is
As shown in FIG. 1, after being shifted by a gear type traveling transmission mechanism (35) arranged between the fifth shaft (34) located below the output shaft (21) in a front view, Differential (3) for the rear wheel (11)
6), and the drive shaft (7) for the front wheel (8) is further connected to the fifth shaft (34), so that the power from the fifth shaft (34) is transmitted to the drive shaft (7). Is transmitted to the front wheel (8) via.

Incidentally, the continuously variable transmission (4) obtains a rotation output by a variable displacement hydraulic pump (4a) driven by the rotation of the input shaft (20) and hydraulic oil supplied from the hydraulic pump (4a). Made of hydraulic motor (4b).

Further, as shown in FIG. 1, an axle case (37) for accommodating the drive shaft (12) for the rear wheel (11) is attached to both side surfaces of the mission case (5). A friction type brake (38) is installed on the transmission case side, and a gear reduction mechanism (39) is installed on the outer end side.

The gear reduction mechanism (39) is configured to drive the axle (40) coaxially arranged with the drive shaft (12) to decelerate, and its operation is performed by a carrier (41) that rotates together with the drive shaft (12). ) 3 planetary gears (42) that are idly supported on the outer side of each axle case
Stationary gear (44) connected to (37) via plate (43)
The three planetary gears (42) are fitted to the inside of each of the three planetary gears (42) so that torque can be transmitted to the axle (40), and have only one tooth less than the stationary system gear (44). By engaging with the gear (45) of the operating system, the axle (40) is driven at a reduction ratio equal to the number of teeth of the gear (44) of the stationary system.

[Another embodiment]

The present invention can be applied to, for example, a vehicle not provided with a mid mount drive shaft other than the above embodiments, and the continuously variable transmission may have any structure.

Further, the present invention can be applied to an agricultural tractor or the like which does not include a vehicle body frame.

It should be noted that reference numerals are added to the claims for convenience of comparison with the drawings, but the present invention is not limited to the structures of the accompanying drawings by the entry.

[Brief description of drawings]

1 is a front view of a mission case, FIG. 2 is a sectional view showing a transmission system from a differential gear to an axle, and FIG. 3 is a mission case. FIG. 4 is a vertical side view, and FIG. 4 is an overall side view of the agricultural tractor. (2) …… Engine, (4) …… CVT, (5) …… Mission case, (8), (11) …… Front and rear wheels, (12) …… Drive shaft, (16) …… External power take-off shaft, (20) …… Input shaft, (21)
…… Output shaft, (23) …… Drive side shaft, (24) …… Driven shaft, (2
5) …… Transmission mechanism for external power, (33) …… Drive side shaft, (34)…
… Drive side shaft, (35) …… Transmission gear mechanism, (36) …… Differential device, (39) …… Deceleration mechanism.

Claims (1)

[Claims] 1. An input shaft (20) to which power from an engine (2) is transmitted is provided in a state of penetrating in a front-rear direction with respect to a casing, and power transmitted to the input shaft (20) is changed in speed and taken out. The continuously variable transmission (4), which is provided with the output shaft (21) projecting rearward from the casing, is installed in the mission case (5).
Mounted on the front surface of the upper part of the transmission shaft, and transmits the power from the output shaft (21) to the front and rear wheels (8) and (11) through the traveling speed change mechanism (35) in the transmission case, and the input shaft ( 20) Power from external transmission power transmission in transmission case (25)
A transmission structure of a vehicle configured to transmit to an external power take-off shaft (16) via an input shaft (20) and an output shaft.
(21) is arranged in parallel in the lateral direction, and the drive side shaft (33) of the traveling speed change mechanism (35) is concentric with the output shaft (21) of the output shaft (21), and the driven side speed change mechanism (35) is driven downward. The side shafts (34) are arranged respectively, and the drive side shaft of the external power transmission mechanism (25) is concentric with the input shaft (20).
(23) to the lower side, the driven side shaft (24) of the external power transmission mechanism (25)
And a drive shaft (1) for transmitting power from the traveling speed change mechanism (35) to the rear wheels (11) via a differential device (36).
A transmission structure for a vehicle, wherein the drive shaft (12) is provided with a gear reduction mechanism (39) for performing deceleration on the axis of rotation of (2).