JP2003237618A - Tractor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To turn the body of a tractor smoothly and efficiently by turning bilateral travel crawlers 7 according to the turning operation value keeping the drive force of an engine constant without making brake force work to the crawlers 7 unlike a conventional way wherein brake force works to the crawlers. <P>SOLUTION: In a half crawler type tractor 1 provided with the travel crawlers 7 in the rear travel section of the body of the tractor 1, the power of a turning speed changing mechanism 34 is transmitted to the travel crawlers 7 through a planet gear mechanism 30 so that the speed of the bilateral travel crawlers 7 is changed stepless. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a half crawler type tractor having a wheel type front wheel in a front traveling portion and a traveling crawler in a rear traveling portion.

[0002]

Conventionally, even in a half crawler type tractor, at the time of turning of the vehicle body, the rear diff mechanism is operated like a wheel tractor by adjusting the left and right braking forces by operating a brake pedal or the like, so that the crawler speed on the outside and inside of the turning can be adjusted. It makes a smooth turn at high speed and low speed, but it is troublesome to operate the brake pedal each time the turn is made.

[0003]

SUMMARY OF THE INVENTION Therefore, according to the present invention, in a half crawler type tractor in which a traveling crawler is provided at a rear traveling portion of an airframe, the output of the turning transmission mechanism is transmitted to the traveling crawler via a planetary gear mechanism. By changing the speed of the left and right traveling crawlers steplessly, the left and right traveling crawlers are given a rotation amount according to the turning operation amount while maintaining the engine driving force without applying the braking force to the left and right traveling crawlers as in the conventional case. This enables the aircraft to smoothly and efficiently turn.

Further, a turning speed change mechanism is connected to a crawler deformation mechanism for changing the ground contact area of the traveling crawler, and the ground area of the traveling crawler is reduced in conjunction with the turning of the machine body. The running crawler with a small area is used to smoothly turn the machine to improve the turning performance and improve the efficiency of the turning work.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. 1 is a side view of the whole, and FIG. 2 is a plan view of the same, in which 1 is a half crawler type tractor,
Left and right wheel type front wheels 4 and 4 are installed on both sides of the hood 3 in which the engine 2 is installed, a round steering handle 5 is provided at the rear of the bonnet 3, and a driver seat 6 is provided behind the handle 5.
Installed on both sides of the driver's seat 6
・ 7 is installed, and the left and right brake pedals 9 and 9 and the clutch pedal 10 are arranged in step 8 on the front side of the driver's seat 6,
The operator is seated on the driver's seat 6 to move and move, and the cultivating rotary working machine 12 is installed up and down via the three-point link mechanism 11 at the rear of the tractor body to perform the cultivating work. .

As shown in FIGS. 3 to 5, the traveling crawler 7 includes a drive sprocket 14 at the center upper side, a front lower tension roller 15, a rear lower idle roller 16 and front and rear rollers 15 and 16. A rear axle case 19 fixed to the left and right outer sides of the mission case 18 by being stretched in a substantially triangular shape with three track rollers 17 disposed in the rear.
While supporting the drive sprocket 14 through the axle 21 on the final case portion 20 of the
The idler frame 23 is fixed to the outside of 0 through the pedestal 22, and the tension roller 15 is rotatably attached to the front end of the idler frame 23 via the guide shaft 24 and the tension spring 25, and is rotatably attached to the rear end of the frame 23. An idle roller 16 is attached.

Further, the three track rollers 17 are mounted at the same height on the track frame 26 below the idler frame 23, and the track frame 2 below the axle 21.
6, the hydraulic crawler deformation cylinder 27 is fixedly mounted, and the tip of the piston rod 28 of the cylinder 27 is connected to the lower surface of the idler frame 23. As shown in FIG. 4, when the cylinder 27 is extended, the track frame 26 is moved downward. By moving the three track rollers 17, the lower center part of the crawler 17 is projected downward so that the ground contact area L1 of the crawler 17 is increased.
Is reduced to an area L2.

As shown in FIG. 6, a left and right planetary gear mechanism 30 forming a forced diff 29 is opened in the transmission case 18, and traveling speed change output via the main and auxiliary speed change mechanisms 31 and 32 is transmitted via a diff input shaft 33. This is transmitted to the left and right planetary gear mechanism 30 and the left and right traveling crawlers 7 are driven in the same direction at substantially the same speed to travel forward or backward. Further, a hydraulic steering case 34 is fixed to the rear surface of the front mission case 18, a hydraulic steering pump 35 and a motor 36 of a hydraulic stepless speed change structure (HST) are installed in the case 34, and the pump 35 is driven. A motor shaft 3 for inputting an output after sub-shifting to the shaft 37 and rotating it by the motor 36
8 is connected to the left and right planetary gear mechanism 30 via the left and right reversing bevel gears 39, and the steering output that continuously changes the speed by the pump 35 and the motor 36 is transmitted to the left and right axles 21 through the left and right planetary gear mechanism 30. As shown, the left and right traveling crawlers 7 are driven at approximately the same speed in the opposite directions to rotate leftward or rightward (when the outer crawler speed is A and the inner crawler speed is B, A≈B).

As shown in FIG. 7, the steering angle of the front wheels 4 operated by the power cylinder 41 of the power steering 40 connected to the steering handle 5 is changed by the pump output of the steering case 34 via the steering arm 42 and the connecting link 43. The continuously variable transmission arm 44 is transmitted to the motor shaft 38 to output a rotation corresponding to the turning angle of the steering handle 5 to reversely drive the left and right drive sprockets 14.

As shown in FIG. 8, a turning sensor 45 of a potentiometer type or the like (which may be an encoder) for detecting the turning angle of the steering wheel 5 from the swing amount of the steering arm 42 and an extension operation of the deforming cylinder 27 are started. Turning setter 46 for setting the standard steering wheel turning angle
And a vehicle speed sensor 4 for detecting the vehicle speed, which is the traveling speed of the aircraft.
7 and a display lamp 48 for displaying the deformation of the traveling crawler 7 by the deforming cylinder 27. The turning sensor 45, the turning setter 46, and the vehicle speed sensor 47 are connected to the controller 49, and the hydraulic pressure is applied to the deforming cylinder 27. The controller 49 is output-connected to the hydraulic electromagnetic switching valve 50 and the display lamp 48 for supplying.

Then, as shown in FIGS. 9 to 11, when turning the machine body when the steering wheel turning angle is equal to or more than the setting,
Cylinder 27 that deforms according to the steering angle
Is extended and the display lamp 48 is turned on to reduce the ground contact area L1 of the traveling crawler 7 to a small ground contact area L2 (L1> L2).
While making a smooth turn by changing the speed to a constant value, the deforming cylinder 27 is mixed when the vehicle speed is a constant value or less in the normal straight traveling, and the ground contact area L1 of the traveling crawler 7 is expanded to perform favorable traveling such as traction.

Further, even when the traveling speed (vehicle speed) is equal to or higher than a certain value in straight traveling, as shown in FIG. 11, the deforming cylinder 27 is extended only according to the traveling speed and the display lamp 48 is turned on to turn on the traveling crawler 7. The ground contact area is changed to a ground contact area L2 smaller than L1 (close to the ground contact state of the wheel wheel) to perform good high speed traveling.

Further, as shown in FIG. 1, a mud-dropping roller 52 is provided on a fender 51 of the traveling crawler 7 so as to be vertically swingable to remove mud adhered to the surface of the traveling crawler 7 when the roller 52 is brought into contact with the traveling crawler 7. Is configured to do.

As is apparent from the above, in the half-crawler type tractor 1 in which the traveling crawler 7 is installed in the rear traveling portion of the machine body, the steering case 34 which is a turning transmission mechanism is provided.
Is transmitted to the traveling crawler 7 via the planetary gear mechanism 30 and the speed of the left and right traveling crawlers 7 is continuously changed, so that the engine driving force is not applied to the left and right traveling crawlers 7 as in the conventional case. While maintaining the above, the amount of rotation corresponding to the amount of turning operation can be given to the left and right traveling crawlers 7 to enable smooth and efficient turning of the machine body.

Further, the ground contact area L1 · L of the traveling crawler 7
Deformation cylinder 2 which is a crawler deformation mechanism that changes 2
7 is connected to a swing speed change mechanism 34, and the ground contact area L1 of the traveling crawler 7 is reduced in conjunction with the swing of the machine body, so that when the machine body is swiveling, the traveling crawler 7 having a small ground contact area corresponding to the amount of swing can smoothly rotate the machine body. It is possible to improve the turning performance by improving the efficiency of the turning work.

Further, as shown in FIGS. 6 and 12, the pump shaft 37 receives an input after the sub-shift, and makes the crawler speed of the inner crawler 7 substantially zero even at the maximum steering angle.
Since the inner crawler 7 is not reversely rotated in any shift range of the sub shift, spin rotation or the like can be prevented.

13 to 17 show another embodiment of the modified structure of the traveling crawler 7. In FIGS. 13 and 14, the front and rear ends of the idler frame 23 are provided with rollers 15 and 16 as idlers. Roller arms 53 and 54 are provided to be extendable and contractable via tension springs 55, and a track frame 26 having three track rollers 17 is fixed to a receiving frame 56 extending below the final case portion 20 from the axle 21 to the track frame 26. The tip of the piston rod 28 of the fixed deformation cylinder 27 is connected to the idler frame 23, and when the deformation cylinder 27 is extended, only the front and rear rollers 15 and 16 are moved upward while maintaining the position of the track roller 17. Ground area L
The contact area L2 is smaller than 1. With this configuration, the ground clearance of the airframe can be kept substantially constant.

In addition, as shown in FIGS. 15 to 17, the roller 1 which is an idler is provided at both front and rear ends of the idler frame 23.
Attaching 5 and 16 rotatably, 3 track rollers 1
The track frame 26 having 7 is divided into the front and rear two frames 57 and 58, and the roller shaft 5 of the central roller 17a is
The piston rod 28 of the deforming cylinder 27 in which the bearing member 60 of 9a is connected and fixed to the final case portion 20 via the frame 61, and is fixed to the bearing tube 62 of the roller shaft 59a.
Connect the tip to the bottom surface of the center of the idler frame 23,
The base ends of the frames 57 and 58 having the front and rear rollers 17b and 17c at their tips are swingably attached to the roller shaft 59a, and the roller shafts 59b and 5 of the front and rear rollers 17b and 17c are attached.
9c and the front-rear pivot shaft 63 of the idler frame 23 are connected via a guide shaft 64 and a compression spring 65, and when the deformation cylinder 27 is extended, the front-rear rollers 15 and 16 are moved upward together with the idler frame 23, and Guide shaft 6
Roller 17b ・ 1 integrally with frames 57 ・ 58 through 4
7c is swung upward around the roller shaft 59a,
The traveling crawler 7 is grounded only by the central roller 17a to bring it closer to the grounded state of the wheel of the wheel type so as to facilitate smooth turning of the machine body and high speed movement.

As is clear from the above, in the half crawler type tractor 1 equipped with the traveling crawler 7 at the rear traveling portion of the machine body, the ground contact area L1 · L of the traveling crawler 7 is provided.
By providing the deforming cylinder 27 that changes the value of 2, the ground contact area L1 of the traveling crawler 7 when the machine body turns or the like
It is possible to reduce the soil pressure by the traveling crawler 7 at the time of turning, reduce the turning resistance to enable smooth turning, and improve the high-speed running property.

A swivel case 34 for swiveling the machine body is also provided.
By connecting the deformation cylinder 27 to the, the ground contact area L1 of the traveling crawler 7 can be easily reduced according to the turning operation amount of the machine body, and the turning performance and the work efficiency can be improved. The deforming cylinder 27 is a roller 15 or 16 that is a supporting rotating body that stretches the traveling crawler 7.
The moving crawler 7 is moved by a simple means of moving the rollers 15, 16 and 17 with the deforming cylinder 27 that is compactly incorporated into the running portion by moving 17
It is possible to improve the efficiency in turning or high-speed work by appropriately reducing the size of the.

[0021]

As is apparent from the above-described embodiments, the present invention is a half crawler type tractor 1 equipped with a traveling crawler 7 at the rear traveling portion of the body of the vehicle.
Is transmitted to the traveling crawler 7 via the planetary gear mechanism 30 to change the speed of the left and right traveling crawlers steplessly. Therefore, without applying a braking force to the left and right traveling crawlers 7 as in the conventional engine, The left and right traveling crawlers 7 can be provided with a rotation amount according to the turning operation amount while maintaining the driving force to enable smooth and efficient turning of the machine body.

Further, the ground contact area L1 · L of the traveling crawler 7
2 to change the crawler deformation mechanism 27 to the swing transmission mechanism 3
4 is connected and the traveling crawler 7 is interlocked with the turning of the aircraft.
Since the ground contact area L1 of the traveling crawler 7 is reduced, the traveling crawler 7 having a small ground contact area according to the turning amount at the time of turning the aircraft.
With this, it is possible to smoothly turn the machine body to improve the turning performance and improve the efficiency in the turning work.

[Brief description of drawings]

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

FIG. 2 is an overall plan view of a tractor.

FIG. 3 is a side view of a traveling crawler section.

FIG. 4 is a deformation explanatory view of a traveling crawler.

FIG. 5 is an explanatory cross-sectional view of a traveling crawler unit.

FIG. 6 is an explanatory diagram of a turning drive system.

FIG. 7 is an explanatory diagram of a turning operation system.

FIG. 8 is a control circuit diagram.

FIG. 9 is a flowchart.

FIG. 10 is a relationship diagram of a steering wheel turning angle and a crawler ground contact area.

FIG. 11 is a relationship diagram between a traveling speed and a crawler ground contact area.

FIG. 12 is a relationship diagram between a steering wheel turning angle and a crawler speed.

FIG. 13 is an explanatory diagram showing another configuration example of the traveling crawler unit.

FIG. 14 is a modification explanatory view of the traveling crawler of FIG.

FIG. 15 is an explanatory diagram showing another configuration example of the traveling crawler unit.

16 is a modification explanatory view of the traveling crawler of FIG.

17 is an explanatory diagram of the track frame portion of FIG.

[Explanation of symbols]

1 tractor 7 traveling crawlers 27 Deformation cylinder (crawler deformation mechanism) 30 Planetary gear mechanism 34 Turning operation mechanism (steering case) L1 ・ L2 contact area

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Claims (2)

[Claims] 1. In a half crawler type tractor having a traveling crawler mounted on a rear traveling portion of an airframe, the output of a turning speed change mechanism is transmitted to the traveling crawler via a planetary gear mechanism to continuously control the speed of the left and right traveling crawlers. A tractor characterized in that it is configured to change to. 2. The crawler deformation mechanism for changing the ground contact area of the traveling crawler is connected to a turning speed change mechanism, and the ground area of the traveling crawler is reduced in association with the turning of the machine body. The tractor according to 1.