JP3133611B2 - Four-wheel drive work vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a standard condition in which power is transmitted to front wheels so that front wheels and rear wheels are driven at substantially the same speed, and that the front wheels are driven at a higher speed than the rear wheels. A four-wheel drive equipped with a front-wheel transmission that switches from a standard state to a speed-up state when the front wheels are steered from a straight position to a set angle or more by setting a speed-up state in which power is transmitted to the front wheels Type work vehicle.

[0002]

2. Description of the Related Art An example of a four-wheel drive type work vehicle equipped with a front wheel transmission as described above is disclosed in Japanese Utility Model Publication No. 6-1464. In this structure, FIG. 2 and FIG.
As shown in the figure, a case (21 in FIG. 3 of the above publication) housing a front wheel transmission (B in FIGS. 2 and 3 of the above publication) is a front axle case (3rd of the above publication). 2 in the figure
0). The power from the transmission case at the rear of the fuselage is transmitted to the front wheel output shaft (1 in FIG. 3 of the above publication).
4), and is transmitted to the rearward input shaft (24 in FIG. 3 of the above-mentioned publication) of the front wheel transmission. In the case of the front wheel transmission, the output shaft ( The reference 23 in FIG. 3 of the above publication and the input shaft of the front axle case are connected.

[0003] With the above structure, when the front wheels are steered within the left and right set angles centering on the straight traveling position, the front wheel transmission is operated in the standard state, and the front wheels and the rear wheels are driven at substantially the same speed. Being driven. When the front wheels are steered at a set angle or more, the front wheel transmission is switched to a speed increasing state, the front wheels are driven at a higher speed than the rear wheels, and a small turning can be smoothly performed by the speed increasing action of the front wheels. By arranging the relatively heavy front wheel transmission at the front of the fuselage, the front-rear balance of the weight of the fuselage is improved.

[0004]

In the four-wheel drive type working vehicle as described above, there are some models in which the front axle case is fixed to the body, and the front axle case is rolled around the longitudinal axis of the body. Some models are freely supported. Thus, when the front wheel transmission is arranged at the front of the body of a four-wheel drive type work vehicle that supports the front axle case in a freely rolling manner, it is necessary to devise a simple structure of the support structure of the front wheel transmission. It is. The present invention is directed to a four-wheel drive type work vehicle in which a front axle case is supported in a freely rotatable manner when a front wheel transmission is arranged at a front part of an airframe, and a support structure of the front wheel transmission is simplified. The purpose is to get.

[0005]

A feature of the present invention resides in the following configuration of the above-described four-wheel drive working vehicle. [1] A first support bracket located at the center front of the front axle case and fixed to the body, and a second support bracket located at the center rear of the front axle case and fixed to the body, The first and second support brackets rotatably support the front axle case around the longitudinal axis of the fuselage, and the front wheel and the rear wheel are driven at substantially the same speed. includes a front wheel transmission freely switching operation speed increasing state which is driven at a high speed, a case for interior of the front wheel transmission, on the second support bracket, said front
The support boss that extends from the axle case
Forming a holding part and extending from the holding part in the circumferential direction
Extend the rising wall, and the tip of the rising wall faces the airframe.
Surface of the rising wall facing the case
The flange to fix the open surface of the case to
A front wheel output shaft that is formed and extends forward from the transmission case at the rear of the fuselage is connected to an input shaft of a front wheel transmission that projects from the case to the side opposite to the front axle case. In the axle case, an output shaft of the front wheel transmission and an input shaft of the front axle case are connected.

[2] A first support bracket located at the center front of the front axle case and fixed to the body, and a second support bracket located at the center rear of the front axle case and fixed to the body. The first and second support brackets support the front axle case in a freely rolling manner around an axis in the longitudinal direction of the body, and the front wheel and the rear wheel are driven at substantially the same speed. includes a front wheel transmission speed increasing state freely switching operation driven faster than wheels, a case for interior of the front wheel transmission, on the second support bracket, said front
The support boss that extends from the axle case
Forming a holding part and extending from the holding part in the circumferential direction
Extend the rising wall, and the tip of the rising wall faces the airframe.
Surface of the rising wall facing the case
The flange to fix the open surface of the case to
And a second support bracket supporting an end of a transmission shaft for shifting in the front wheel transmission, and a front wheel output shaft extending forward from a transmission case at a rear portion of the vehicle to the front axle. The output shaft of the front wheel transmission is connected to the input shaft of the front axle case in the case or in the front axle case.

[0007]

According to the features of the first and second aspects, for example, as shown in FIGS. 3 and 2, the first axle case 11 and the second support bracket 15 fixed to the body allow the front axle case 11 to move in the longitudinal direction of the body. Case 1 in which the front wheel transmission 10 is mounted so as to be freely rollable around the axis P1
6 is supported by the second support bracket 15. As a result, the front wheel transmission 10 (case 16) is
Since it is supported by the second support bracket 15 for one, a dedicated support member for the front wheel transmission 10 (case 16) is not required. Case 16 for housing front wheel transmission 10
In (2), since the surface (left side in the drawing) connected to the second support bracket 15 is an open surface, when the open surface of the case 16 is connected to the second support bracket 15, the second support bracket 15 Of the cover member. This eliminates the need for a dedicated lid member for the case 16 of the front wheel transmission 10.

The front wheel transmission 1 is mounted on the second support bracket 15.
In the case where the case 0 and the case 16 are attached, for example, in FIG.
Each part of the front wheel transmission 10 is attached, and finally a case 16 is connected to the second support bracket 15 from the right side of the drawing. As described above, the front wheel transmission 10 and the case 16 are attached to the second support bracket 15 from one direction (the side opposite to the front axle case 11).

[0009]

According to the first and second aspects of the present invention, in a four-wheel drive type work vehicle in which a front axle case is rotatably supported, a second support bracket for the front axle case is supported by a support member of a front wheel transmission, and Also, it can be used also as a cover member of the case of the front wheel transmission, so that the structure can be simplified and the weight can be reduced. Since the front wheel transmission and the case are attached to the second support bracket from one direction,
The assemblability was also good.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, an engine 3 and a main clutch 4 are arranged at the front of the body supported by a pair of left and right front wheels 1 and a rear wheel 2, and a control unit 5 and a transmission case 6 are arranged at the rear of the body. An agricultural tractor, which is an example of a driven work vehicle, is configured.

The power from the engine 3 is transmitted to the transmission case 6 via the main clutch 4 and the transmission shaft 7, and the transmission is shifted by a transmission (not shown) in the transmission case 6 to the right and left rear wheels 2. Is transmitted. As shown in FIG. 2, the power branched right before the rear wheel 2 is transmitted to the transmission case 6.
To the first front wheel output shaft 8 (corresponding to the front wheel output shaft) and the second
The power is transmitted to the front wheel transmission 10 via the front wheel output shaft 9 (corresponding to the front wheel output shaft), and transmitted from the front wheel transmission 10 to the left and right front wheels 1 via the front axle case 11.

Next, the front axle case 11 and the front wheel transmission 1
The support structure of No. 0 will be described. As shown in FIGS. 2 and 5, one rectangular support plate 13 is fixed across the left and right frames 12 at the front of the body, and a first support bracket 14 is attached to the front of the support plate 13. A second support bracket 15 is fixed to a rear portion of the support plate 13. A pair of cylindrical support bosses 1 are provided on the front and rear surfaces at the left and right centers of the front axle case 11.
1a and 11b are fixed, and the front and rear support boss portions 11
a, 11b are inserted into the first and second support brackets 14, 15, and the front axle case 11 is
It is supported so as to freely roll around one.

As shown in FIGS. 3 and 2, the case 16 which houses the front wheel transmission 10 has a bottom portion formed on the rear side of the fuselage (right side in FIG. 3) and the front side of the fuselage (right side in FIG. 3). Has a large open surface. With the front wheel transmission 10 mounted inside, the open surface of the case 16 is
The support bracket 15 is connected to a surface on the opposite side of the front axle case 11. The second support bracket 15
A support boss 1 extending from the front axle case 11
Forming and holding a holding portion for fitting and holding 1b
Extending the rising wall in the circumferential direction from the part,
A fixed portion for the body is formed at the tip, and the rising wall is
Place the open surface of the case on the surface facing the case
The front wheel shift is formed by forming a flange portion 15C for attaching and fixing.
The end of the transmission shaft 21 for shifting in the device 10 is
It is supported by two support brackets 15.

Next, the front wheel transmission 10 will be described. As shown in FIGS. 3 and 2, the front wheel transmission 1 is moved rearward from the case 16 (the side opposite to the front axle case 11).
The 0 input shaft 17 protrudes, and the input shaft 17 and the second front wheel output shaft 9 are connected via the sleeve 18. Input shaft 1
7 and an output shaft 19 of the front wheel transmission 10 are coaxially butted against each other so as to be relatively rotatable relative to each other, and within the support boss 11b of the front axle case 11 (in the second support bracket 15). The input shaft 20 of the axle case 11 and the output shaft 19 of the front wheel transmission 10 are connected by a spline structure.

As shown in FIG. 3, a transmission shaft 21 is disposed parallel to the input shaft 17 and the output shaft 19,
Of the second support bracket 15 and the case 16
And the transmission gear 17a of the input shaft 17 and the transmission gear 21a of the transmission shaft 21 are engaged. Speed-up gear 2
2 is externally fitted to the output shaft 19 by a needle bearing so as to be relatively rotatable, and the transmission gear 21b of the transmission shaft 21 and the speed increasing gear 22 are engaged. The shift member 23 has a spline structure and is fitted around the output shaft 19 so as to be freely rotatable and slidable. The steering mechanism (not shown) of the front wheel 1 and the shift member 23 are cam mechanisms (not shown). Are mechanically interlocked.

With the above structure, when the front wheel 1 is steered within the straight-ahead position or the left and right set angles sandwiching the straight-ahead position, the shift member 23 is slid to the right as viewed in FIG. The projection 23a of the shift member 23 is engaged with the projection 17b of the transmission gear 17a. In this state, the input shaft 17 and the output shaft 19 are connected to each other, and the power transmitted to the input shaft 17 is transmitted to the front wheel 1 via the output shaft 19 and the input shaft 20 in the standard state, and the front wheel 1 and the rear wheel 2 are driven at substantially the same speed.

Next, when the front wheel 1 is steered beyond a set angle, the shift member 23 is slid to the left in FIG. 3 and the projection 23 b on the opposite side of the shift member 23 It engages with the projection 22a. In this state, the power transmitted to the input shaft 17 is transmitted to the front wheel 1 via the transmission shaft 21 and the speed increasing gear 22, the output shaft 19 and the input shaft 20 in a speed increasing state, and the front wheel 1 is transmitted from the rear wheel 2. The vehicle is also driven at a high speed, so that the front wheel 1 is accelerated so that the small turning is smoothly performed.

Next, a support structure for the second front wheel output shaft 9 will be described. As shown in FIGS. 4, 2, and 6, the support member 24 is formed by pressing a reverse triangular plate material to form a ring-shaped step portion 24 a and forming a pair of mounting portions 24 b. A ring member 25 obtained by rolling a plate into a cylindrical shape.
Are fixed by welding along the outer periphery of the step portion 24a of the support member 24. A nut 34 is welded and fixed to a support plate 33 obtained by bending a rectangular plate material into an L-shape in a side view. Is connected to the lower part. In this case, the support plate 33 and the nut 34 are prevented from rotating by bringing the end of the support plate 33 into contact with the outer surface of the first cover 26 described later.

As shown in FIGS. 4 and 2, the end of a cylindrical first cover 26 covering the second front wheel output shaft 9 is supported by a step 24a of a support member 24, and the second front wheel output shaft is supported. The end of the cylindrical second cover 27 that covers the front wheel transmission 9
And the first and second covers 2
6 and 27 are connected by a ring member 28. As shown in FIG. 4, an inwardly protruding portion 26a is partially formed near the end of the first cover 26, and
A bearing 29 and a seal member 30 are arranged between 6a and the step portion 24a of the support member 24, and the bearing 29 and the seal member 30 are positioned by the protrusion 26a and the step portion 24a.

With the above structure, the first and second covers 2
In 6, 27, the body front side of the second front wheel output shaft 9 is connected by a sleeve 18 to the input shaft 17 of the front wheel transmission 10, and the body rear side of the second front wheel output shaft 9 is supported by bearings 29. The front wheel output shaft 9 is connected to the first front wheel output shaft 8 via the universal joint 31. A cover 32 that covers the vicinity of the universal joint 31 is provided, and the cover 32 is supported by the ring member 25 of the support member 24.

[Another Embodiment] In the embodiment shown in FIG. 2, the power from the first front wheel output shaft 8 is applied to the input shaft 1 of the front wheel transmission 10 via the second front wheel output shaft 9.
7, the second front wheel output shaft 9 may be omitted and the first front wheel output shaft 8 may be directly connected to the input shaft 17 of the front wheel transmission 10.

Incidentally, reference numerals are written in the claims for convenience of comparison with the drawings, but the present invention is not limited to the configuration of the attached drawings by the entry.

[Brief description of the drawings]

FIG. 1 is an overall side view of an agricultural tractor.

FIG. 2 is a longitudinal side view of the vicinity of a front axle case, a front wheel transmission, and first and second front wheel output shafts.

FIG. 3 is a vertical side view of the vicinity of a second support bracket, a front wheel transmission, and a case of the front axle case.

FIG. 4 is a longitudinal sectional side view of a support member near a connecting portion between first and second front wheel output shafts.

FIG. 5 is a longitudinal rear view of the vicinity of a second support bracket of the front axle case.

6 is a front view of the vicinity of the support member of FIG. 4 as viewed from the left side of the paper.

[Explanation of symbols]

 Reference Signs List 1 front wheel 2 rear wheel 6 transmission case 8, 9 front wheel output shaft 10 front wheel transmission 11 front axle case 14 first support bracket 15 second support bracket 16 front wheel transmission case 17 input shaft of front wheel transmission 19 front wheel transmission Output shaft 20 Input shaft of front axle case 21 Transmission shaft for shifting in front wheel transmission P1 Shaft center in body longitudinal direction

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-195024 (JP, A) JP-A-64-41424 (JP, A) JP-A-1-127417 (JP, A) 64825 (JP, U) Japanese Utility Model 63-137034 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60K 17/28-17/36 A01B 69/00 B62D 49/00

Claims (2)

(57) [Claims] 1. A first support bracket (14) located at a central front portion of a front axle case (11) and fixed to an airframe;
A second support bracket (15) located at the center rear of the front axle case (11) and fixed to the body; and the first and second support brackets (14) and (15) provide the front axle. The case (11) is connected to the longitudinal axis (P
1) The front wheel (1) and the rear wheel (2) are supported so as to be freely rolled around, and the front wheel (1) is driven at substantially the same speed. Front wheel transmission (10) that can be freely switched to high speed state
And a case (1) housing the front wheel transmission (10).
6) and the front axle case is provided on the second support bracket (15).
(11) The support boss (11b) extending from
A holding part (15A) to be formed is formed and the holding part is formed.
Extend the rising wall (15B) from (15A) in the circumferential direction.
To the airframe at the tip of the rising wall (15B).
The case of the rising wall (15B) forming a fixing portion
Place the open surface of the case (16) on the surface facing (16).
The front wheel output shafts (8) and (9), which form a flange portion (15C) for attachment and fixation and extend forward from the transmission case (6) at the rear of the fuselage, are connected to the case (6).
Is connected to an input shaft (17) of a front wheel transmission (10) projecting to the opposite side to the front axle case (11), and within the case (16) or the front axle case (11),
Within the output shaft (19) of the front wheel transmission (10) and the front axle case (11), the output shaft (19) of the front wheel transmission (10) and the input shaft (2) of the front axle case (11).
0) is connected to the four-wheel drive type work vehicle. 2. A first support bracket (14) fixed to the body at a central front portion of the front axle case (11),
A second support bracket (15) located at the center rear of the front axle case (11) and fixed to the body; and the first and second support brackets (14) and (15) provide the front axle. The case (11) is connected to the longitudinal axis (P
1) The front wheel (1) and the rear wheel (2) are supported so as to be freely rolled around, and the front wheel (1) is driven at substantially the same speed. Front wheel transmission (10) that can be freely switched to high speed state
And a case (1) housing the front wheel transmission (10).
6) and the front axle case is provided on the second support bracket (15).
(11) The support boss (11b) extending from
Forming a holding part to hold and circumferentially from the holding part
The rising wall extends in the direction of
A case for forming the fixing portion with respect to the body,
Attach the open surface of the case to the surface facing
A front end of the transmission shaft (21) for shifting in the front wheel transmission (10).
The front wheel output shafts (8) and (9), which are supported by the second support bracket (15) and extend forward from the transmission case (6) at the rear of the fuselage, are connected to the case (6).
Is connected to an input shaft (17) of a front wheel transmission (10) projecting to the opposite side to the front axle case (11), and within the case (16) or the front axle case (11),
A four-wheel drive work vehicle, wherein an output shaft (19) of the front wheel transmission (10) and an input shaft (20) of a front axle case (11) are connected.