JP2006335240A - Semi-crawler type working vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To brake a rear crawler type traveling device at a turning central side by a turning force at turning when a front wheel is turned by a steering device by connecting a brake arm of a brake device and a knuckle arm by a brake wire. <P>SOLUTION: In the semi-crawler type working vehicle (tractor 1) provided with front wheels 2L, 2R and the rear crawler type traveling devices 3L, 3R, a front wheel steering device and brake devices 34L, 34R of the rear crawler type traveling devices 3L, 3R are interlocked and connected through a connection member. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a semi-crawler type work vehicle provided with a wheel-type front wheel and a rear crawler-type traveling device, and more particularly to improvement of turning performance of a semi-crawler type tractor.

Tractors, especially agricultural tractors, can be roughly classified into wheel type (wheel type) and crawler type (crawler type). The wheel type is a two-wheel, four-wheel, four-wheel drive type, rear wheel drive type, front wheel The crawler type can be subdivided into a full crawler type and a semi-crawler type.
The semi-crawler type tractor is a tractor provided with a wheel type front wheel and a rear crawler type traveling device, and has a performance intermediate between a wheel type and a full crawler type on a soft ground.
In order to improve the turning performance in this semi-crawler type tractor, a technique is known in which the steering angle of the front wheels is detected, and the braking device of the semi-crawler inside the turning is braked when the steering angle exceeds a set angle. ing. (See Patent Document 1)
JP-A-10-45052

  However, in the conventional technology, when the angle exceeds the set angle, a predetermined braking force is applied to the inside of the turn, and the rotation is stopped. There were inconveniences such as roughing the running surface and not being able to turn smoothly.

  Accordingly, in order to solve the above-described problems, the present invention is configured such that when the front wheel is turned by the steering device, the brake arm and the knuckle arm of the brake device are interlocked and connected by the brake wire. The purpose is to brake the rear crawler type traveling device on the turning center side with power and smoothly perform the turning.

  The problems to be solved by the present invention are as described above. Next, means for solving the problems will be described.

  That is, in the first aspect, in the semi-crawler tractor including the front wheels and the rear crawler type traveling device, the front wheel steering device and the brake device of the rear crawler type traveling device are interlocked and connected via the connecting member.

  According to a second aspect of the present invention, braking is performed in proportion to the turning operation angle of the steering device.

  According to a third aspect of the present invention, the knuckle arm of the steering device and the brake device are connected via a wire.

  As effects of the present invention, the following effects can be obtained.

  According to the first aspect of the present invention, since the front wheel steering device and the brake device for braking the rear crawler type traveling device are interlockedly connected, the rear crawler type traveling that becomes the turning center at the same time as the steering device is rotated. It becomes possible to turn while braking the device, and the turn can be performed smoothly by reducing the opportunity to turn while pushing the front wheel by the crawler type traveling device during turning.

  In claim 2, it is possible to smoothly turn regardless of the turning radius. Moreover, it can turn with a good feeling.

  According to the third aspect of the present invention, the rear crawler type traveling device can be turned while braking with a mechanically simple configuration.

Next, embodiments of the invention will be described.
Hereinafter, a semi-crawler type agricultural tractor (hereinafter, tractor 1) will be described as an example of a semi-crawler type work vehicle.
1 is an overall side view showing the overall configuration of a semi-crawler tractor according to an embodiment of the present invention, FIG. 2 is a schematic plan view showing the configuration of a steering mechanism and a crawler drive unit, and FIG. 3 is a rear crawler type FIG. 4 is a schematic plan view showing the configuration of the steering mechanism unit and the crawler driving unit during a right turn.

  As shown in FIGS. 1 and 2, the tractor 1 has an engine 16 mounted inside a hood 15 at the front of the airframe, and a clutch housing, a transmission case 17 and the like are integrally connected from the engine 16 to the main body of the vehicle body. It is a frame. Wheel-type front wheels 2L, 2R are provided on both the left and right sides of the bonnet 15 so as to be swingable to the left and right with respect to the center pivot 31. A steering post 22 is provided in the rear part of the bonnet 15 and in the cabin 18. A steering handle 23 protrudes from the upper portion, and the front wheels 2L and 2R can be steered by a steering mechanism 21 described later by rotating the steering handle 23.

  As shown in FIG. 2, the steering mechanism unit 21 which is a front wheel steering device extends a handle shaft 24 below a circular steering handle 23, and a steering unit 25 is provided below the handle shaft 24. The rotation of the steering handle 23 is decelerated by the unit 25, and an arm 26 attached to the steering unit 25 and a drag arm 28 pivotally attached to the vehicle body are connected by a drag rod 27.

  The rear traveling device of the tractor 1 has a crawler type configuration, and the rear crawler type traveling device 3 includes a pair of left and right track frames 9, driving wheels 7, wheels 5 a, 5 b, 5 c, and a driven idler 6. And the tension roller 4, the driving wheel 7, the rollers 5 a, 5 b, 5 c, the driven idler 6, and the crawler belt 8 wound around the outer periphery of the tension roller 4. The rollers 5 a, 5 b, 5 c, the driven idler 6, and the tension roller 4 are rotatably supported on the track frame 9.

  The drive wheel 7 is fixed on an axle 12 supported by a rear axle case 10 projecting outward from the left and right sides of the rear portion of the transmission case 17, and the teeth of the drive wheel 7 are connected to the crawler belt 8. The crawler belt 8 is rotationally driven by meshing with an engagement hole provided in the periphery.

Further, as shown in FIG. 3, the track frame 9 has a substantially inverted T shape when viewed from the side, and the rolling wheels 5a, 5b and 5c, the driven idler 6 and the tension roller 4 are supported on the horizontal frame 9a in the front-rear direction. The A vertical frame 9b is erected above the front and rear central brakes of the horizontal frame 9a, a swing fulcrum is provided at the upper part of the vertical frame 9b, and the axle 12 is positioned at the lower part. In other words, in the present embodiment, in this embodiment, the fulcrum shaft 13 protrudes laterally from the side surface of the mission case 17, and the upper portion of the vertical frame 9 b is inserted into the fulcrum shaft 13 and pivotally supported. An arc-shaped long hole 9c centered on the fulcrum shaft 13 is opened below, and the axle 12 is inserted into the long hole 9c.
With this configuration, when traveling on an uneven farm field or road, the rear crawler traveling device 3 swings around the fulcrum shaft 13, but from the fulcrum shaft 13 to the tip of the rear crawler traveling device 3. Is longer than the distance from the axle 12 to the tip of the rear crawler type traveling device 3, so that when the rear crawler type traveling device 3 swings, the tip of the rear crawler type traveling device 3 becomes a handle from the fulcrum shaft 13. Thus, the crawler belt 8 is not slackened, and the crawler belt 8 is not detached during the uneven traveling.

  The power of the engine 16 is shifted by the transmission in the transmission case 17 and then transmitted to the left and right rear crawler type traveling devices 3L and 3R via the differential device 11 and the axle in the rear axle case 10. Left and right side clutch devices and brake devices 34L and 34R are arranged between the differential device 11 and the axle 12, and power transmission and braking are independently performed from the differential device 11 to the left and right crawler type traveling devices 3L and 3R. Is possible.

The drag arm 28 is formed in a substantially triangular shape, and the left and right tops of the drag arm 28 are pivotally supported by the aircraft. The left and right tops of the drag arm 28 are end portions on the left and right center sides of the tie rods 29L and 29R. The other ends of the tie rods 29L and 29R are pivotally connected to one ends of the left and right knuckle arms 30L and 30R, respectively. The other side of the knuckle arms 30L and 30R is fixed to a rotating case that is rotatably supported around the king pins 37L and 37R, and the front wheels 2L and 2R are attached to the rotating case. In this manner, the rotation of the steering handle 23 is transmitted to the knuckle arms 30L and 30R, and the front wheels 2L and 2R are rotated left and right to constitute a front wheel steering device. However, a steering hydraulic control valve is provided below the steering shaft 24 of the steering handle 23. On the other hand, a power steering cylinder is disposed on the tie rods 29L and 29R, and the power steering cylinder and the steering hydraulic control valve are connected to each other, thereby providing a power steering mechanism. It is also possible to configure.
The center portion of the front axle 32 is pivotally supported by a center pivot 31 projecting from the vehicle body, and the front axle 32 is formed to be swingable about the center pivot 31.

  When the steering handle 23 is rotated, the drag rod 27 is pushed and pulled through the arm 26 attached to the steering unit 25, and the drag arm 28 is rotated by pushing and pulling the drag rod 27. The left and right knuckle arms 30L and 30R are rotated via the left and right tie rods 29L and 29R connected to the drag arm 28, and the left and right front wheels 2L and 2R are rotated to the left or right.

  Next, a configuration for braking the inside of the turning of the rear crawler type traveling devices 3L and 3R using the rotational force of the steering handle 23 in the steering mechanism 21 when turning right (left) according to the present invention will be described.

  Conventionally, when turning the aircraft, the semi-crawler type tractor is configured to brake the left and right brake devices 34L and 34R to reduce the turning radius in the same manner as the wheel type tractor. However, the brake actuator is operated by hydraulic pressure. Therefore, it is necessary to attach a sensor for detecting the rotation angle of the steering handle 23 or to form an oil passage, which increases the cost.

  Therefore, in the present invention, the brake arms 35L and 35R for braking the brake devices 34L and 34R and the knuckle arms 30L and 30R constituting the steering mechanism 21 are interlocked and connected by the brake wires 36L and 36R. Thus, when the front wheels 2L and 2R are turned by the steering mechanism portion 21 which is a front wheel steering device, the rear crawler type traveling device 3L or the rear crawler type traveling device 3R on the turning center side is turned by the turning force at the time of turning. It is supposed to brake and turn smoothly.

  2 and 4 are schematic views showing the configuration of the steering mechanism and the crawler driving unit, and the tractor 1 is turned by rotating the steering handle 23 using the steering mechanism 21 which is a front wheel steering device. It is constituted as follows.

  First, one end of the brake wire 36 is fixed on the knuckle arm 30 and the other end is connected to the brake arm 35 of the brake device 34 on the left and right other side. In addition, a spring or the like is disposed at an appropriate place so that the wire does not loosen. In the present embodiment, the right (left) knuckle arm 30R (30L) and the left (right) brake arm 35L (35R) are connected by a brake wire 36L (36R), and the brake wires 36L and 36R are " “X” crosses in a letter shape.

Next, the case where the tractor 1 turns right will be described with reference to FIG.
When the steering handle 23 is rotated clockwise, the rotational force is transmitted to a bevel gear (not shown) in the steering unit 25, and the drag rod 27 is moved forward via the arm 26 attached to the steering unit 25 via the bevel gear. When pressed, the drag arm 28 rotates clockwise in plan view.

Then, the left and right tie rods 29L and 29R and the knuckle arms 30L and 30R are pushed leftward as the drag arm 28 rotates in the clockwise direction in plan view. Specifically, the right knuckle arm 30R rotates toward the front axle 32 around the king pin 37R, while the left knuckle arm 30L rotates toward the front wheel 2L around the king pin 37L. At the same time, the front wheels 2L and 2R rotate to turn right.
As a result, the brake wire 36L that has been fixed to the right knuckle arm 30R only relaxes, and no force is exerted on the brake device 34L, and the left brake device 34L does not operate. On the other hand, the brake wire 36R fixed to the left knuckle arm 30L is pulled forward and outward, and the brake device 34R operates.

  Accordingly, only the right brake device 34R operates to brake the right drive wheel 7R, and the tractor 1 turns rightward by decelerating or stopping the right rear crawler type traveling device 3R. At this time, since the brake arm 35 is rotated in proportion to the rotation of the steering handle 23, the braking force increases and the turning radius can be decreased as the turning angle increases. Therefore, the feeling of the turning operation can be improved.

  Conversely, when the tractor 1 turns to the left, the operation is the reverse of the above.

  Note that the turning operation angle of the front wheels 2L and 2R is proportional to the turning amount of the steering mechanism 21 which is the steering device, and the rear part is proportional to the turning operation angle of the front wheels 2L and 2R. The crawler type traveling devices 3L and 3R are configured to brake.

The whole side view which showed the whole structure of the semi-crawler type tractor which concerns on one Example of this invention. The schematic plan view which shows the structure of a steering mechanism part and a crawler drive part. FIG. 5 is an explanatory diagram of the relationship between the fulcrum shaft and the oscillating radius of the axle when the rear crawler type traveling device swings. The schematic plan view which shows the structure of the steering mechanism part and crawler drive part at the time of right turn.

Explanation of symbols

2L, 2R Front wheel 3L, 3R Rear crawler type traveling device 21 Steering mechanism 22 Steering post 23 Steering handle 24 Handle shaft 25 Steering unit 26 Arm 27 Drag rod 28 Drag arm 29L / 29R Tie rod 30L / 30R Knuckle arm 34L / 34R Brake device 35L / 35R Brake Arm 36L / 36R Brake Wire

Claims (3)

  A semi-crawler type tractor including a front wheel and a rear crawler type traveling device, wherein the front wheel steering device and a brake device of the rear crawler type traveling device are interlocked and connected via a connecting member.   The semi-crawler type work vehicle according to claim 1, wherein braking is performed in proportion to a turning operation angle of the steering device.   The semi-crawler type work vehicle according to claim 1 or 2, wherein a knuckle arm of the steering device and a brake device are connected via a wire.

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