JP3432027B2 - Tractor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tractor having a crawler type rear traveling device used in agriculture, civil engineering, construction and the like.

[0002]

2. Description of the Related Art For example, in an agricultural tractor for paddy fields and the like, four wheels are wheel type tractors having tire wheels, full crawler type tractors having only tires without crawlers, and front wheels having tire wheels and rear wheels having crawler wheels. There are semi-crawler type tractors and the like, each having advantages and disadvantages. Wheel type tractors are mainly lightweight type, and are equipped with car wheels, tires with float strike, high lag tires, etc. to ensure running in wetlands, but rear tires sink in strong wetlands. Therefore, it may be difficult to drive.

The full-crawler type tractor is medium to large in size and has a low ground pressure and a large traction force. Therefore, it is currently most suitable as a dedicated machine for wetlands, but it has low mobility and can be used as a part of a wheel type tractor. There is a problem such as low.
The semi-crawler type tractor has an intermediate property between the wheel type tractor and the full crawler type tractor, and can be used as a wheel type tractor while having a low ground pressure. This semi-crawler type tractor consists of a vehicle body having a transmission case containing an engine and a power transmission device, steering front wheels suspended in the lower front portion of the vehicle body, and left and right projections from the rear portion of the vehicle body to prevent power transmission from the power transmission device. Has a rear axle to which power is transmitted and left and right rear traveling devices that are driven by the left and right rear axles, and the left and right rear traveling devices are supported with respect to the tire wheels mounted on the rear axle and the vehicle body. It has a driven wheel and a crawler wrapped around the tire wheel and the driven wheel (refer to a new edition handbook of agricultural machinery issued by Corona).

[0004]

The above-mentioned conventional semi-crawler type tractor can be constructed simply by providing front driven wheels on the wheel type tractor and winding the crawlers around the wheel type wheels and front driven wheels. Although it can be configured, it is easy to change to a wheel type tractor, but it is difficult to hold the crawler around the wheel type wheel, and it is difficult to reliably transmit the driving force and the peripheral speed becomes faster,
Since there are no driven wheels behind the wheel type wheels, there are various problems that it is difficult to regulate the lifting of the front wheels when the working machine is mounted on the rear part of the tractor.

According to the present invention, a rear traveling device is provided with a drive wheel which is replaceable with a wheel type wheel on a rear axle, and front and rear driven wheels are supported by a wheel frame which is detachably fixed to a vehicle body. By winding the crawler around the driven wheel, the ground pressure can be lowered by running the crawler, and proper driving force can be reliably transmitted, the crawler can be held securely, and the front wheel can be prevented from rising. It is an object to provide a tractor that can be easily changed.

[0006]

A first specific means for solving the problems in the present invention is a vehicle body 4 having a transmission case 3 having an engine 2 and a power transmission device 14 built-in, and a front lower portion of the vehicle body 4. The front steering wheel 5 that is suspended, the rear axle 6 that projects from the rear portion of the vehicle body 4 to the left and right to transmit the power from the power transmission device 14, and the left and right rear traveling that is driven by the left and right rear axles 6 e Bei the device 7, the left and right rear driving device 7, a drive wheel 9 mounted to the rear axle 6 interchangeably with wheel type wheel 8, the wheel frame 10 detachably fixed to the vehicle body 4 , possess a longitudinal driven wheels 11, 12 supported on the wheel frame 10, and a crawler 13 wound around the drive wheel 9 and front and rear driven wheels 11, 12
The vehicle body 4 is transmitted from the engine 2 to the rear axle 6.
Front wheel that splits the motive power to the front wheel 5 and transmits and disconnects freely
A steering device 28 for steering the drive device 25 and the front wheels 5.
The front wheel drive device 25 and the steering device 2
8 When the front wheel 5 is steered by a certain angle or more,
Rotate the front wheel 5 from the idle state at a higher peripheral speed than the crawler 13.
A front wheel drive interlocking mechanism 26 for changing the driving state to
Is that that.

In addition to the first concrete means, the second concrete means for solving the problems in the present invention is such that the wheel frame 10 of the left and right rear traveling device 7 is detachably fixed to the lower surface of the vehicle body 4. And the left and right sides of the mounting frame 15 protruding left and right are detachably connected. The vehicle body 4 has a convex portion 18 protruding downward on the lower surface, and the lower surface of the mounting frame 15 is positioned higher than the lower surface of the convex portion 18. It is located. The third concrete means for solving the problems in the present invention is the first
Alternatively , in addition to the specific means of 2 , the space portion 1 in which the left and right drive wheels 9 are formed at midway portions in the width direction of the wheel frame 10.
It is inserted in 7.

The fourth concrete means for solving the problems in the present invention is, in addition to any one of the first to third concrete means, a connecting mechanism 21 for connecting the working machine 20 to the rear portion of the vehicle body 4. The front and rear driven wheels 11 and 12 of the rear traveling device 7 are located on the front lower side and the rear lower side of the drive wheel 9, and the rear end of the rear traveling device 7 formed by the rear driven wheel 12 is connected to the work machine 20. That is, it is located in the vicinity of the connection position with the connection mechanism 21. The fifth concrete means for solving the problem in the present invention is the concrete means according to any one of the first to fourth aspects , in which the front and rear driven wheels 11 and 12 of the rear traveling device 7 are located below the drive wheel 9 in front of and below. And a rear traveling device 7 which is located on the lower rear side and is formed by the front driven wheel 11.
The front part of the vehicle is the boarding / alighting part 2 formed in the middle part of the tractor front-back direction.
Ru der that is positioned substantially below the 2.

A sixth concrete means for solving the problems in the present invention is, in addition to any one of the first to fifth concrete means, a braking device 27 and a front wheel 5 capable of independently braking the left and right rear axles 6. A steering device 28 for steering is provided, and the front wheel 5 is provided between the brake device 27 and the steering device 28.
Is provided with a one-brake interlocking mechanism 29 that operates the steering-side braking device 27 when the steering wheel is steered by a certain angle or more.

[0010]

The tractor 1 drives the drive wheels 9 of the rear traveling device 7 by the drive force transmitted from the engine 2 to the left and right rear axles 6 via the power transmission device 14 in the transmission case 3, and the drive wheels 9 The crawler 13 wound around the front and rear driven wheels 11 and 12 travels around, and travels at a low ground contact pressure. The drive wheel 9 mounted on the rear axle 6 is replaceable with the wheel type wheel 8, and the wheel frame 10 supporting the front and rear driven wheels 11 and 12 is detachably fixed to the vehicle body 4, and the four-wheel wheel is provided. Easily changed to a type tractor.

Front and rear driven wheels 11 and 12 are arranged in front of and behind the driving wheel 9 to increase the ground contact area of the crawler 13.
The rear end of the rear traveling device 7 is located in the vicinity of the connecting position between the working machine 20 and the connecting mechanism 21 to make the rear overhang amount R as long as possible, and the front portion of the rear traveling device 7 is connected to the boarding / alighting section 22. It is located substantially below and serves as an auxiliary step for getting on and off the boarding / alighting section 22. The wheel frame 10 of the left and right rear traveling device 7 is
The intermediate frame 15 is detachably connected to the vehicle body 4 so as to be detachably connected to the left and right sides of the intermediate frame 15 so as to be easily and firmly attached to the vehicle body 4.
Located above the lower surface of the convex portion 18 at the bottom of the tractor 1
The ground clearance is secured. The drive wheel 9 is inserted into the space 17 formed in the middle portion of the wheel frame 10 in the left-right width direction so that the drive wheel 9 has a diameter as large as possible.

The diameter of the drive wheel 9 is set so that the peripheral speed of the drive wheel 9 is lower than the peripheral speed of the front wheel 5 during driving, and the front wheel is linked with the steering of the steering device 28 at a certain angle or more. When the front wheel drive device 25 is changed to the front wheel drive state via the drive interlocking mechanism 26, the front wheels 5 are changed from the idle state to the drive state in which the front wheels 5 rotate at a higher peripheral speed than the crawler 13, and the left and right rear traveling devices 7 are driven.
Make a small turn with one brake applied to the steering side. When the front wheels 5 are steered at a certain angle or more via the steering device 28, the steering side braking device 27 is operated via the one-brake interlocking mechanism 29, and the left and right rear axles 6 are independently braked to make a small turn.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 8, a tractor 1 is a semi-crawler type tractor that can be changed to a four-wheel wheel type, and a vehicle body 4 is composed of an engine 2, a transmission case 3, a front axle frame, etc., and a front axle frame is provided at a lower front portion of the vehicle body 4. It has a front wheel 5 which is suspended via a vehicle, a rear axle 6 which projects left and right from a rear portion of the vehicle body 4, and a left and right rear traveling device 7 which is driven by the left and right rear axle 6. The transmission case 3 is formed of a flywheel housing, a clutch housing, a transmission case, and the like.

As shown in FIG. 7, the power transmission device 14 of the tractor 1 applies the driving force of the engine 2 to the main clutch 33.
Is transmitted to the transmission 34 of the traveling transmission system via the rear transmission and the rear left and right rear axles 6 via the rear axle differential device 35. As shown in FIG. 3, the rear axle 6 is supported by a rear axle case 16 that projects left and right from a brake case 32 at the rear of the vehicle body 4. Further, the power entering the rear axle differential device 35 is branched and transmitted to the front wheel drive device 25. The front wheel drive device 25 has a front wheel drive switching mechanism 36, and drives the front wheel 5 in an idle state and a drive state. It is possible to switch to the state. 37 is a transmission of the PTO transmission system,
Power is transmitted to the shaft 38.

A steering device 28 for steering the front wheels 5 is provided on the vehicle body 4. Between the steering device 28 and the front wheel drive switching mechanism 36 of the front wheel drive device 25, a turning angle of the front wheels 5 is provided. A front wheel drive interlocking mechanism 26 is provided which operates the front wheel drive switching mechanism 36 when the angle exceeds a certain angle. This front wheel drive interlocking mechanism 26
When the front wheels 5 are steered by a predetermined angle or more, for example, about 40 degrees or more, the front wheels 5 are electrically detected to operate the solenoid valve, and the hydraulic clutch of the front wheel drive switching mechanism 36 is switched to change the front wheels 5 Can be changed from the idle state to the driven state.

The front wheel drive interlocking mechanism 26 may mechanically detect the steering of the front wheels 5 and switch the mechanical clutch of the front wheel drive switching mechanism 36 by a shifter.
Further, the front wheel drive switching mechanism 36 uses the hydraulic clutch and the speed change gear to rotate the front wheel 5 in the idle state and the wheel type wheel 8.
It is also possible to change the driving state to a substantially constant circumferential speed and to change the driving state to the wheel type wheel 8 at a high speed. Even in such a case, the front wheel drive interlocking mechanism 26 causes the front wheel 5 to idle. It operates so as to change from the state to the driving state of approximately constant circumferential speed.

A brake device 27 capable of independently braking the left and right rear axles 6 is provided in the left and right brake cases 32. As shown in FIG. 8, a front wheel is provided between the brake device 27 and the steering device 28. A one-brake interlocking mechanism 29 that operates according to the turning angle of 5 is provided. The one-brake interlocking mechanism 29 electrically detects the front wheel 5 when the front wheel 5 is steered by a certain angle or more by a detecting means 40 such as a potentiometer or a tachometer, and outputs right and left electromagnetic waves according to the steering angle. The auxiliary cylinder 4 that operates the steering side (cut side) of the valve 41 and is connected to the left and right foot pedals 42
3 is operated to operate the steering side braking device 27 to brake the rear axle 6. In addition, in FIG.
Reference numeral 4 denotes a pump, 45 denotes a master cylinder, 46 denotes an equalizer, and the auxiliary cylinder 43 belongs to the one-brake interlocking mechanism 29.

1 to 3, the tractor 1 is a vehicle body 4
The hydraulic device 50 is mounted on the upper rear part, the pair of left and right lower links 52 and the top link 53 of the three-point link mechanism 51 are connected to the rear part, and the hitch 54 is mounted on the lower rear part. The mechanism 51, the hitch 54, and the like constitute a connecting mechanism 21 that connects the working machine 20 such as a rotary cultivator so as to be able to move up and down or pulls the trailer. Reference numeral 55 denotes a cabin mounted on the vehicle body 4, which is detachably fixed to the vehicle body 4 via a bracket fixed to the vehicle body 4 and the rear axle case 16 and the like. Reference numeral 74 denotes a fender of the cabin 55, which is normally provided so as to surround the upper and front portions of the wheel type wheel 8, and the crawler type rear traveling device 7 also surrounds a part of the upper and front portions thereof.

Each of the left and right rear traveling devices 7 is supported by drive wheels 9 mounted on a rear axle 6, a wheel frame 10 that is detachably fixed to the vehicle body 4, and front and rear ends of the wheel frame 10. It has front and rear driven wheels 11 and 12, and a crawler 13 wound around the drive wheel 9 and the front and rear driven wheels 11 and 12. As shown in FIGS. 2 to 4, the left and right wheel frames 10 are formed by a U-shaped member or a square tubular member, have fixing brackets 57 at a plurality of front and rear positions, and both left and right side portions of the mounting frame 15 fixed to the vehicle body 4. Is detachably connected to the front driven wheel 11 via a movable bracket 58 and tension adjusting means 59, and the rear driven wheel 12 is rotatably supported on the rear portion.

The front and rear halfway portions of the wheel frame 10 are
A set of two rolling wheels 6 via one or a plurality of rolling wheel supports 60
1 is supported, and this roller 61 is also inscribed in the crawler 13. The crawler 13 is an elastic crawler with or without a cored bar, and the same crawler 13 as that used for the full crawler or the semi-crawler can be used. The wheel frame 10 has a space portion 17 formed in the middle portion of the front-rear direction in the left-right width direction, and the lower portion of the drive wheel 9 is inserted into the space portion 17.
Are located on the upper side, and even if the drive wheels 9 have a larger diameter, they do not interfere with each other.

The mounting frame 15 is detachably secured to the underside of the car body 4 and and is projected to the left and right, front and rear transverse members 63 and 64 extending in the left-right direction, the rear transverse member from the left and right ends of the front transverse member 63 The front vertical member 65 reaching 64 and the rear horizontal member 6
4 has a rear vertical member 66 extending rearward from both left and right ends. A pair of rising brackets 67 are provided on the upper surface of the front lateral member 63 so as to sandwich the vehicle body 4 from the left and right, and fixed to the side surfaces of the vehicle body 4 (for example, a flywheel housing) by bolts. A connecting portion 68 such as a bolt hole for bolting is formed on the lower surface of the vehicle body 4, and bolts are fixed to the fixing bracket 57 of the wheel frame 10 at the center of the front vertical member 65 and the front and rear portions of the rear horizontal member 64. The connecting bracket 69 is welded.

An auxiliary fixing tool 70 is fixed to the upper surface of the rear vertical member 66 and is bolted to a mounting tool 71 provided on the rear axle case 16, so that the vehicle body 4 and the mounting frame 1 can be connected.
The attachment with 5 is reinforced. The vehicle body 4 has a convex portion 18 protruding downward in order to dispose the front wheel drive switching mechanism 36 therein. For example, the gears and hydraulic packs that constitute the front wheel drive switching mechanism 36 are provided in a cassette case, and the cassette case is incorporated into the vehicle body 4 from the outside, and the lower surface of the cassette case is the tractor 1. The minimum ground clearance is set.

The lower surface of the mounting frame 15 is positioned above the lower surface of the convex portion 18 and fixed to the vehicle body 4, so that the mounting frame 15 does not lower the minimum ground clearance of the vehicle body 4. The convex portion 18 may be formed of a front wheel differential case. The left and right rear traveling device 7 includes front and rear driven wheels 11 for the drive wheels 9 located in the middle of the front and rear,
12 are located on the lower front side and the lower rear side, and are arranged in a triangular shape in a side view. The front overhang amount F of the front driven wheel 11 and the rear overhang amount R of the rear driven wheel 12 around the drive wheel 9 are defined. It is set to a ratio of 7: 3 or around it.

The larger the rear overhang amount R of the rear driven wheel 12, the greater the effect of preventing the tractor 1 from rolling backward, that is, the effect of restricting the lifting of the front wheel 5, but becomes an obstacle to the connection of the working machine 20. Therefore, the rear end of the rear traveling device 7 formed by the rear driven wheels 12 is located near the connecting position between the working machine 20 and the connecting mechanism 21. Also,
As the front driven wheel 11 has a larger front overhang amount F, the ground contact area of the crawler 13 can be further expanded and the ground contact pressure can be further reduced, but the maneuverability becomes low and it becomes difficult to get on and off the tractor 1. Therefore, the front portion of the rear traveling device 7 formed by the front driven wheels 11 is positioned substantially below the boarding / alighting portion 22 to a position where it can function as an auxiliary step.

The rear traveling device 7 disengages the wheel frame 10 together with the mounting frame 15 from the vehicle body 4 and the drive wheel 9 from the rear axle 6 and then mounts the wheel type wheel 8 on the drive wheel 9. It can be the same as a conventional wheel type tractor. Wheel type wheel 8 is a cage wheel,
A tire with a float strike, a high lug tire, or the like, and when it is mounted on the drive wheel 9 in a large wheel distance state, it can be mounted on the drive wheel 9 even when the mounting frame 15 is mounted on the vehicle body 4. FIG. 9 shows a first modified example, in which the left-right length of the mounting frame 15 is shortened, and the wheel frame 10 is provided with a connecting portion 10A protruding toward the vehicle body 4 side.
5 is connected to the vehicle body 4 with the mounting frame 15 mounted on the vehicle body 4 and the wheel type wheel 8 mounted on the drive wheel 9.
Can be installed. The wheel frame 10 is composed of two left and right plates, which are long in the front-rear direction, and upper and lower parts of the left and right plates that are connected to each other by lateral plates at a plurality of front and rear positions.

FIG. 10 shows a second modification, in which the mounting frame is not provided and the vehicle body 4 is attached to the wheel frame 10.
A large connecting portion 10B that largely protrudes to the side is provided, and is configured to be directly attached to the vehicle body 4 via this connecting portion 10B. The wheel type wheel 8 is attached to the drive wheel 9 only by detaching the wheel frame 10. It is possible. In the tractor 1 configured as described above, the driving force from the engine 2 is passed through the power transmission device 14 in the transmission case 3 such as the main clutch 33, the transmission 34, the rear axle differential device 35, etc. Is transmitted to the driving wheels 9 of the rear traveling device 7 by this driving force.
The crawler 13 wound around the driving wheel 9 and the front and rear driven wheels 11 and 12 is rotated while being guided by a plurality of rolling wheels 61.

The front and rear driven wheels 11 and 12 are arranged in front of and behind the drive wheel 9 to increase the ground contact area of the crawler 13, and the crawler 13 runs at a low ground pressure. Further, the rear driven wheel 12 has a long rear overhang amount R, and thus the coupling mechanism 21
Even when the working machine 20 is attached via the, the lifting of the front wheel 5 is restricted. The drive wheel 9 has a diameter as large as possible and is inserted into the space 17 of the wheel frame 10 so as to avoid interference with the wheel frame 10. Obtainable.

However, the diameter of the drive wheel 9 is smaller than that of the front wheel 5, and the front wheel drive device 25 is connected via the front wheel drive interlocking mechanism 26.
Is set to a front wheel drive state, the peripheral speed of the drive wheels 9 is set to be lower than the peripheral speed of the front wheels 5, and the front wheel drive interlocking mechanism 26 is operated by steering the steering device 28 at a certain angle or more. When the front wheels 5 are rotated from the idle state to the driven state and rotated at a higher peripheral speed than the crawler 13, the left and right rear traveling device 7 becomes relatively lower than the front wheels 5, and the rear axle diff device 35 causes the diff action. The tractor 1 makes a small turn so that the front wheel 5 turns around with one brake applied to the steering side.

When the one-brake interlocking mechanism 29 is actuated by steering the steering device 28 at a certain angle or more, the steering side braking device 27 is actuated, and only one of the steering side rear axles 6 is independently braked. The tractor 1 makes a small turn so that the front wheel 5 turns around with one brake applied to the steering side. Although the front wheel drive interlocking mechanism 26 and the one-brake interlocking mechanism 29 can make a small turn only by operating one of them, the small turn performance is improved by operating both of them.

The present invention is not limited to the above embodiment, but can be variously modified. For example, the rear traveling device 7 may omit the rollers 61 or make the overhang amounts F and R substantially the same.

[0031]

According to the present invention described in detail above, in the tractor 1, the left and right rear traveling devices 7 are mounted on the rear axle 6 so as to be replaceable with the wheel type wheels 8 and the vehicle body 4. On the other hand, since the wheel frame 10 is detachably fixed, the front and rear driven wheels 11 and 12 supported by the wheel frame 10, and the crawler 13 wound around the drive wheel 9 and the front and rear driven wheels 11 and 12 are provided. , The ground pressure can be lower than the wheel type tractor, the maneuverability can be higher than the full crawler type, and the wheel type wheel exchange function equivalent to that of the conventional semi-crawler type can be provided. However, the wound state of the crawler 13 can be reliably maintained, the ground contact pressure can be further lowered, and the lifting of the front wheel 5 can be effectively regulated.

Further, the wheel frame 1 of the left and right rear traveling device 7
0 is detachably fixed to the lower surface of the vehicle body 4 and is detachably connected to both left and right side portions of the mounting frame 15 which projects left and right, and the vehicle body 4 has a convex portion 18 protruding downward on the lower surface,
Since the lower surface of the mounting frame 15 is positioned higher than the lower surface of the convex portion 18, the wheel frame 10 can be firmly attached to the vehicle body 4, and the ground clearance of the tractor 1 can be secured. Since each of the left and right drive wheels 9 is inserted into the space portion 17 formed in the middle portion of the wheel frame 10 in the left-right width direction, the wheel frame 10 is set to the upper side as much as possible and the drive wheel 9 is set to the largest possible diameter. Can be formed.

The vehicle body 4 has a connecting mechanism 21 for connecting the working machine 20 at the rear part thereof, and the front and rear driven wheels 11, 12 of the rear traveling device 7 are connected.
Are located on the front lower side and the rear lower side of the drive wheel 9, and the rear driven wheel 12 is
Since the rear end of the rear traveling device 7 formed in 1 is located in the vicinity of the connecting position of the working machine 20 and the connecting mechanism 21, the rear overhang amount R is made as long as possible to prevent the front wheel 5 from moving. The tilting of the vehicle body 4 that lifts up can be more effectively regulated. The front and rear driven wheels 11 and 12 of the rear traveling device 7 are located on the front lower side and the rear lower side of the drive wheel 9, and the front portion of the rear traveling device 7 formed by the front driven wheel 11 is formed at a middle portion in the front and rear direction of the tractor. Since it is located substantially below the boarding / alighting section 22, the rear traveling device 7 can serve as an auxiliary step for the boarding / alighting section 22.

A front wheel drive device 25 for branching the power transmitted from the power transmission device 14 to the rear axle 6 to the front wheels 5 and for transmitting and disconnecting the front wheels 5 and a steering device 28 for steering the front wheels 5 are provided. Device 25 and steering device 28
And a front wheel drive interlocking mechanism 26 that changes the front wheel 5 from the idle state to the drive state when the front wheel 5 is steered by a certain angle or more. Since the diameter of the drive wheel 9 is set so that the peripheral speed of the drive wheel 9 becomes low, the front wheel 5 can be driven to rotate at a higher peripheral speed than the crawler 13 when the tractor 1 is turned. With the one-side brake applied to the steering side of the traveling device 7,
Allows small turns.

A braking device 27 capable of independently braking the left and right rear axles 6 and a steering device 28 for steering the front wheels 5 are provided, and the front wheels 5 are steered at a certain angle or more between the braking device 27 and the steering device 28. Since the one-brake interlocking mechanism 29 that operates the steering-side brake device 27 when the vehicle is operated, the steering-side brake device 27 is automatically operated when the tractor 1 is turned, and the left and right rear axles are operated. 6
Independent braking of only one side enables a small turn.

[Brief description of drawings]

FIG. 1 is an overall side view showing an embodiment of the present invention.

FIG. 2 is a side view of the main part.

FIG. 3 is a sectional rear view of the same portion.

FIG. 4 is a plan view of a main part.

FIG. 5 is a side view of a mounting frame.

FIG. 6 is a front view of a mounting frame.

FIG. 7 is a schematic explanatory diagram of a power transmission device of a tractor.

FIG. 8 is an explanatory diagram showing a brake device and a one-brake interlocking mechanism.

FIG. 9 is a partial cross-sectional rear view showing a first modified example of the present invention.

FIG. 10 is a partial cross-sectional rear view showing a second modification of the present invention.

[Explanation of symbols]

1 tractor 2 engine 3 transmission cases 4 car body 5 front wheels 6 rear axle 7 Rear traveling device 8 wheel type wheels 9 drive wheels 10 wheel frame 11 front driven wheel 12 Rear driven wheel 13 crawlers 14 Power transmission device 15 Mounting frame 17 Space Department 18 convex 20 working machines 21 Connection mechanism 22 Boarding area

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-6-1007013 (JP, A) JP-A-6-64557 (JP, A) JP-A-6-16150 (JP, A) JP-A-8- 85480 (JP, A) Actual development Sho 60-54674 (JP, U) Special table 4-505902 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B62D 55/04

Claims (6)

(57) [Claims] 1. An engine (2) and a power transmission device (1)
4) A vehicle body (4) having a transmission case (3) containing the same
And the steering front wheel (5) suspended on the lower front part of the vehicle body (4)
And a rear axle (6) projecting left and right from the rear part of the vehicle body (4) to which power from the power transmission device (14) is transmitted.
If, e Bei and after left driven by the left and right rear axle (6) traveling device (7), the left and right rear driving device (7), wheel type wheel (8)
Drive wheels (9) mounted on the rear axle (6) interchangeably with
A wheel frame (10) detachably fixed to the vehicle body (4), front and rear driven wheels (11, 12) supported by the wheel frame (10), the drive wheel (9) and the front and rear slaves. The crawler (1) wound around the driving wheels (11, 12)
3) and which have a, the body (4) is transferred to the rear axle (6) from the engine (2)
Divides the reached power to the front wheel (5) and transmits it freely.
Front wheel drive (25) and front wheel (5) steering
And a front wheel drive device (2).
5) between the steering device (28) and the front wheel (5)
The front wheel (5) when it is steered over a certain angle
Drive state of rotating at a higher peripheral speed than the crawler (13)
A tractor characterized by being provided with a front wheel drive interlocking mechanism (26) that is changed to . 2. The wheel frame (10) of the left-right rear traveling device (7) is detachably fixed to the lower surface of the vehicle body (4) and is attachable and detachable to both left and right sides of a mounting frame (15) protruding left and right. The vehicle body (4) has a convex portion (18) protruding downward on the lower surface, and the lower surface of the mounting frame (15) is positioned higher than the lower surface of the convex portion (18). The tractor according to claim 1. 3. A space portion (1) in which each of the left and right drive wheels (9) is formed at an intermediate portion in the left-right width direction of a wheel frame (10).
The tractor according to claim 1 or 2 , wherein the tractor is inserted in 7). 4. The body (4) has a working machine (20) at a rear portion thereof.
A rear traveling device (7) having a connecting mechanism (21) for connecting
The front and rear driven wheels (11, 12) of the rear drive device (7) are located on the front lower side and the rear lower side of the drive wheel (9), and the rear end of the rear traveling device (7) formed by the rear driven wheel (12) is 20) and connection mechanism (2
The tractor according to any one of claims 1 to 3, wherein the tractor is located in the vicinity of the connection position with 1). 5. The front and rear driven wheels (1) of the rear traveling device (7).
1, 12) are located on the front lower side and the rear lower side of the drive wheel (9), and the front part of the rear traveling device (7) formed by the front driven wheel (11) is formed in the middle part of the tractor front-rear direction. Boarding area (2
2. It is located substantially below 2).
The tractor according to any one of to 4 . 6. A brake capable of independently braking the left and right rear axles (6).
Steering for steering the brake device (27) and front wheels (5)
And a braking device (27) and a steering device.
Between the ring device (28) and the front wheel (5) is at a certain angle or less.
When the vehicle is steered upward, the braking device on the steering side (27)
The tractor according to any one of claims 1 to 5, further comprising a one-brake interlocking mechanism (29) that operates .