JPH1134940A - Crawler travel device for work vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the ground contact area of a crawler as wide as possible, to increase the tractive force of a car body, and to prevent the settlement of the car body in a work vehicle having a triangular crawler travel device. SOLUTION: Drive shafts 1 are protruded to both the right and left side sections of an axle case extended on a transmission case 13, crawler drive wheels 2 are provided on the drive shafts 1, front driven wheels 3F and rear driven wheels 3R are arranged at the front and rear below the drive shafts 1, and crawlers 4 are suspended between the crawler drive wheels 2 and the front and rear driven wheels 3F, 3R to constitute a crawler travel device in this tractor. The distance L2 from the axis of the crawler drive wheels 2 to the rear driven wheels 3R is set longer than the distance L1 from the axis of the crawler drive wheels 2 to the tip sections of the front driven wheels 3F, and the diameter R2 of the rear driven wheels 3R is set smaller than the diameter R1 of the front driven wheels 3F.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a construction of a crawler type traveling device for a work vehicle.

[0002]

2. Description of the Related Art Conventionally, like a semi-crawler type agricultural tractor disclosed in Japanese Utility Model Laid-Open No. 5-78682,
A drive shaft protrudes on both left and right sides of the vehicle body, a crawler drive wheel is provided on this drive shaft, a front driven wheel and a rear driven wheel are disposed below and behind the drive shaft, and between the crawler drive wheel and the front and rear driven wheels. 2. Description of the Related Art There is known a work vehicle in which a crawler is stretched to form a crawler-type traveling device.

[0003]

In a working vehicle having the above-described crawler type traveling device, it is desirable to increase the contact area of the crawler as much as possible in order to increase the traction force of the vehicle body and to suppress the sinking. . However,
If the distance between the driven wheels having the same diameter in the front and rear is set wide in order to widen the contact area of the crawler, the driving surface of the crawler (the portion where the driving wheel and the crawler mesh) is reduced, and the traction force is reduced or the crawler is easily detached. The problem arises.

[0004]

The present invention employs the following technical means in order to solve the above problems. That is, the drive shafts 1, 1 protrude from the left and right sides of the vehicle body,
Crawler drive wheels 2 and 2 are provided on the drive shafts 1 and 1, and a front driven wheel 3F and a rear driven wheel 3R
And the crawler driving wheels 2 and 2 and the front and rear driven wheels 3
In a working vehicle in which a crawler 4 is stretched between F and 3R to constitute a crawler-type traveling device, a distance L2 from the axis of the crawler drive wheel 2 to the rear driven wheel 3R is set forward from the axis of the crawler drive wheel 2 A crawler-type traveling device for a work vehicle, characterized in that the distance is set to be longer than the distance L1 of the leading end of the driven wheel 3F and the diameter R2 of the rear driven wheel 3R is set smaller than the diameter R1 of the front driven wheel 3F. .

[0005]

The crawler-type traveling device for a working vehicle constructed as described above has a distance L2 from the axis of the crawler drive wheel 2 to the rear driven wheel 3R and a distance from the axis of the crawler drive wheel 2 to the front driven wheel 3F. Is set to be longer than the distance of the tip end, so that the contact area of the crawler 4 can be made as large as possible, and the diameter R of the driven wheel 3R after setting the distance to be long.
2 is set smaller than the diameter R1 of the front driven wheel 3F, so that compared with a configuration in which driven wheels of the same system are arranged at the same position,
The driving surface of the crawler 4 can be secured. As a result, it is possible to prevent the crawler 4 from falling off while increasing the tractive force of the work vehicle.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The objects and solutions of the present invention are as described above. A semi-crawler agricultural tractor (hereinafter, tractor 10) will be described below as an example of a working vehicle. As shown in FIG. 2, the tractor 10 mounts an engine 12 inside a hood 11 at the front of the fuselage, and integrally connects a clutch housing, a transmission case 13 and the like from the engine 12 to form a main frame of a vehicle body. .
On both the left and right sides of the bonnet 11, wheel-type front wheels 14, 14 are provided so as to be freely rollable with respect to the center pivot shaft 15, and a steering post 16 is provided at the rear of the bonnet 11, and a steering handle 17 protrudes above this. And set it up. The rotation of the steering wheel 17 causes the front wheel 1 to rotate.
4 and 14 are steered.

A cockpit 18 is provided behind the steering handle 17, and a speed change lever 19 for traveling and a position lever 20 for lifting and lowering the work implement are provided beside the cockpit 18. The crawler-type traveling device 5 of the tractor 10 has a configuration in which a crawler frame 21 which is an iron driven wheel support member is provided below the rear part of the transmission case 13 as shown in FIG. I have.
More specifically, the crawler frame 21 is an iron frame having a substantially "H" shape when viewed from the top (A), and has a configuration in which rolling support portions 21A, 21A extending front and rear are provided on both left and right sides. . The front end of the wheel supporting portion 21A is hollow and has a large-diameter (diameter R1) front driven wheel 3F.
And the front driven wheel mounting arm 30 is fitted and fixed. The rear end portion of the wheel supporting portion 7A is also formed in a hollow shape, and the rear passive wheel mounting arm 31 for supporting the rear driven wheel 3R having a smaller diameter (diameter R2) smaller than the front driven wheel 3F. Are fitted and fixed. And, between these front and rear driven wheels 3F and 3R,
A first wheel 22A, a second wheel 22B, and a third wheel 22C are arranged and provided in order from the front.

Further, inside the crawler frame 21,
An upright portion 21B extending upward is provided, and a drive shaft insertion portion 21C detachable with a bolt is provided at the upper end of the upright portion 21B. This drive shaft insertion portion 21C
When the front driven wheel 3F and the rear driven wheel 3R are mounted, the distance between the drive shaft insertion portion 21 and the front driven wheel 3F is L1, the drive shaft insertion portion 21 and the rear driven wheel
Assuming that the distance from R is L2, the configuration is such that L1 <L2. In addition, these left and right standing portions 2
1B and 21B are connected to the front and rear connection frames 21D and 21 respectively.
An attachment portion 21F is provided on the front connection frame 21D, which is connected at E, and connects a piston tip portion of the hydraulic cylinder 23 described later.

On the other hand, in the tractor 10, an axle case 13A is provided to extend to the rear left and right of the transmission case 13, and the drive shaft 1 is provided to protrude from the axle case 13. When the crawler 4 is mounted on the crawler frame 21 of the tractor 10, first, the insertion portions 21C of the crawler frame 21 are inserted into the right and left drive shafts 1, respectively, and the sprocket-shaped crawler drive wheels 2 are inserted into the distal ends. Attach. Then, the insertion portion 21C and the upright portion 21B of the crawler frame 21 are connected by bolts. Further, the fixed end of the hydraulic cylinder 23 is rotatably attached to the side of the transmission case 13, and the tip of this piston is attached to the oblong hole 21 of the attachment piece 21E.
Connect to G. As a result, the tractor 10 controls the crawler 4 according to the detection value of the slope sensor 24 described later.
Crawler type traveling device 5 so that the contact area of
Can be rotated around the drive shaft 1. And finally, the crawler 4 is connected to the crawler driving wheel 2 and the front and rear driven wheels 3F,
3R, between the rolling wheels 22A, 22B, 22C.

The rear part of the transmission case 13 of the tractor 10 will be described. At the rear of the transmission case 13, a slope sensor 24 for detecting the front-back inclination of the vehicle body,
A cylinder case 25 or the like containing a hydraulic cylinder for lifting and lowering the work machine is provided, and lift arms 26, 26 provided on the side of the case 25 by expansion and contraction of a piston of the hydraulic cylinder.
Is rotated. A three-point link mechanism including a top link 27 and left and right lower links 28, 28 is provided at the rear of the mission case 13, and the working machine 3 is configured to be connectable thereto. In the illustrated example, the rotary working machine is connected.

The crawler-type traveling device 5 of the tractor 10 constructed as described above has a distance L2 from the axis of the crawler drive wheel 2 to the rear driven wheel 3R, and a distance L2 from the axis of the crawler drive wheel 2 to the front driven wheel 3F. Because the distance is set longer than the distance of the tip, the contact area of the crawler 4 can be made as large as possible.
At this time, since the diameter R2 of the rear driven wheel 3R disposed far from the drive wheel 1 is set smaller than the diameter R1 of the front driven wheel 3F, compared with the configuration in which the driven wheels having the same diameter are disposed at the same position,
The driving surface of the crawler 4 (the portion where the driving wheel and the crawler mesh) can be secured, and while the traction force of the tractor 10 is increased,
Further, the crawler 4 can be prevented from falling off. Also,
Since the driven wheel having a small diameter is used as the rear driven wheel 3R, compared with the case where the magnitude relationship of the diameter is set in reverse, the driven wheel gets over a soil mass or an inclined surface that collides with the front end of the crawler 4 during traveling in the forward direction. It can be easier.

[Brief description of the drawings]

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

FIG. 2 is a front view showing a cross section of a part of the crawler traveling device.

FIG. 3A is a top view of a crawler frame. (B) Front view of a crawler frame. (C) Side view of the crawler frame.

[Explanation of symbols]

 Reference Signs List 1 drive shaft 2 crawler drive wheel 3F front driven wheel 3R rear driven wheel 4 crawler 5 crawler traveling device 10 tractor

Claims (1)

[Claims] 1. A drive shaft 1, 1 protrudes from both left and right sides of a vehicle body. Crawler drive wheels 2, 2 are provided on the drive shaft 1, 1, and a front driven wheel 3F is provided below and behind the drive shaft 1, 1. In a working vehicle in which a rear driven wheel 3R is arranged and a crawler 4 is stretched between the crawler driving wheels 2 and 2 and front and rear driven wheels 3F and 3R to constitute a crawler type traveling device, a shaft of the crawler driving wheel 2 is provided. The distance L2 from the center to the rear driven wheel 3R is the distance L from the axis of the crawler driving wheel 2 to the tip of the front driven wheel 3F.
A crawler-type traveling device for a working vehicle, wherein the length is set to be longer than 1, and the diameter R2 of the rear driven wheel 3R is set smaller than the diameter R1 of the front driven wheel 3F.