JPH1129073A - Crawler traveling device of working vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a crawler from being disengaged from a driving wheel for crawler, a driven wheel or the guide of a roller by mounting a supporting member supporting the driven wheel or the roller so as to be rotatable around the shaft center of a drive shaft. SOLUTION: After the other end side of a drive shaft 1 is inserted/passed into/through a bearing part 5C of a crawler frame 5 in a state that a driving wheel 2 for crawler is mounted on one end part of the drive shaft 1 and a crawler frame 5 to be a supporting member is located on the lower side of a transmission case 13, the other end side of the drive shaft 1 is mounted on a bearing hole opened in an extension part 13a of the transmission case 13. The crawler frame 5 is made rotatable with the shaft center of the drive shaft 1 as a center so as to stretch a crawler 6 between a crawler driving wheel 2, front and rear driven wheels and each roller. As a result, the crawler 6 is not disengaged from the driving wheel 2 for crawler, the front and rear driven wheels or the guide of each roller at the time of rotating the crawler frame 5 and the falling of the crawler 6 can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a construction of an agricultural work vehicle and a construction work vehicle, and more particularly to a structure having a crawler type traveling device.

[0002]

2. Description of the Related Art Conventionally, a pair of left and right drive shafts protrude from a side portion of a vehicle body, and a crawler drive wheel is provided on the drive shaft, and a support member for supporting a driven wheel or a rolling wheel is disposed below the drive shaft. In addition, there is known a work vehicle in which a crawler is stretched between the crawler driving wheel and a driven wheel or a rolling wheel to constitute a crawler traveling device. For instance,
No. 78682 discloses a pair of left and right wheel-type front wheels,
A semi-crawler type tractor is provided with a pair of left and right crawler-type rear traveling devices, and at the end of the vehicle body, a work machine can be connected so as to be able to move up and down.

[0003]

In a work vehicle having a conventional crawler type traveling device, a support member for supporting a rolling wheel or a driven wheel is fixedly attached to a vehicle body, so that it can be used when turning or traveling at high speed. In addition, there is a problem that the resistance of the crawler is large, the running surface is roughened, and the crawler is worn out at an early stage. In order to address this problem, a method of changing the state of the support member to reduce the contact area of the crawler as much as possible is considered. In this case, the crawler is driven from the guide of the driving wheel, the driven wheel, or the rolling wheel. It is necessary to change the state of the support member so that the circumference of the crawler does not change as much as possible so as not to come off.

[0004]

The present invention employs the following technical means in order to solve the above problems. That is, a pair of left and right drive shafts 1 and 1 protrude from the side of the vehicle body, and crawler drive wheels 2 and 2 are provided on the drive shafts 1 and 1, and driven wheels 3. A support member 5 for supporting the rolling wheels 4 is arranged, and a crawler 6 is stretched between the crawler driving wheels 2 and 2 and the driven wheels 3 or the rolling wheels 4 to constitute a crawler type traveling device 7. A supporting member 5 for supporting the driven wheel 3 or the rolling wheel 4 is rotatably mounted around the axis of the drive shafts 1 and 1. It was a traveling device.

[0005]

According to the crawler-type traveling device for a working vehicle constructed as described above, the supporting member 5 for supporting the driven wheels 3 or the rolling wheels 4 is driven by the whole supporting member 5 for driving the crawler 6. Since it rotates around the axis 1, the circumferential length of the crawler 6 does not change. Therefore, even if the support member 5 is rotated, the crawler 6 is driven by the crawler driving wheel 1, the driven wheel 3,.
Alternatively, the crawler 6 can be prevented from falling off the guide of the rolling wheels 4.

[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 15, and a steering post 16 is provided at the rear of the bonnet 11, and a steering handle 17 protrudes above this. Provided, this steering handle 1
7, the front wheels 14, 14 are steered. A steering angle sensor 18 is provided inside the post 16 as means for detecting the turning state of the tractor 10.

The vicinity of the cockpit 19 of the tractor 10 will be described.
0, a position lever 21 for lifting and lowering the work implement is provided. The rotation base of the position lever 21 is provided with a potentiometer 22 for detecting the operation angle, and the height of the working machine 24 is changed so that the lever operation angle matches the set angle of a lift arm 23 described later. Has become. In the vicinity of the guide of the lever 21, there is provided a control mode changeover switch 25 for switching the control mode of the crawler frame 5 as a supporting member for supporting the front and rear driven wheels 3F, 3R or the rolling wheels 4A, 4B, 4C described later. I have.

The rear traveling device 7 of the tractor 10 is of a crawler type. A crawler frame 5 for supporting the rolling wheels 4A, 3B, 3C and the driven wheels 3F, 3R is provided below the transmission case 13. The wheels 4A, 3B, 3
C and the crawlers 6 are wound around the driven wheels 3F and 3R. More specifically, as shown in FIG. 3, the crawler frame 5 is a substantially “H” -shaped iron frame as viewed from above (A). 5A. The front end of the wheel supporting portion 5A is formed in a cylindrical shape so as to receive the supporting portion of the front driven wheel 3F.
The rear end of A is provided with a holding portion that rotatably supports the rear driven wheel 3R. The front end of the wheel supporting portion 5A is fitted to the supporting portion of the front driven wheel 3F by sliding it back and forth inside the cylinder so that the front and rear position can be adjusted. A first rolling wheel 4A, a second rolling wheel 4B, and a third rolling wheel 4C are arranged between the front and rear driven wheels 3F and 3R in this order from the front.

The crawler drive wheel 2 is provided at a tip end of a drive shaft 1 projecting outward from a left and right extending portion 13a at a rear portion of the transmission case 13, and an outer peripheral portion of the crawler 6 is engaged therewith. The sprocket-shaped projections 2A that engage with the holes 6A are provided, and the crawler 6 is driven by the engagement. Also, the rolling wheels 4A, 4B, 4
At the center of the left and right widths of C, there is provided a recess 4A that sandwiches the central projections 6B, 6B provided in two rows on the left and right inside the crawler 6, and the left and right displacement of the crawler 6 is regulated by the recess 4A to change the rotation direction. It is configured to guide. The front and rear driven wheels 3F and 3R are connected from the first rolling wheel 4A to the third rolling wheel 4C.
When the ground contacts the ground, it is located slightly above the ground surface to guide the rotation of the crawler 6.

[0010] A flat plate-like standing portion 5B is provided upward from the inside of the wheel supporting portion 5A, and a drive shaft bearing 5C is connected to the upper portion. The left and right standing portions 5B are connected to each other at front and rear positions by front and rear connection portions 5D and 5E. The front connecting portion 5D is provided with a mounting piece 5F, on which a hydraulic cylinder 30 serving as an actuator for rotating the crawler frame 5 is provided.
Are connected. The mounting piece 5F is a flat plate with an elongated hole 5G provided at the front end thereof, and is configured so that the crawler frame 5 can swing by a fixed amount in a "free mode" described later. .

When the crawler 6 is mounted on the crawler frame 5 of the tractor 10 constructed as described above, first, the crawler driving wheel 2 is mounted on one end of the drive shaft 1 and the crawler frame 5 is mounted below the transmission case 13.
After the other end of the drive shaft is inserted into the bearing 5C of the crawler frame 5, the drive shaft is attached to the bearing hole opened in the extension 13a of the transmission case 13.
Further, the fixed end of the hydraulic cylinder 30 is rotatably attached to the side of the transmission case 13, and the tip of the piston is attached to the elongated hole 7G of the attachment piece 5F. And
The crawler 6 includes the crawler driving wheel 2 and the front and rear driven wheels 3F, 3
R, bridge between the wheels 4A, 4B, 4C.

As a result, the crawler frame 5 can be turned back and forth by the expansion and contraction of the piston of the hydraulic cylinder 30, and the frame 5 turns around the axis of the drive shaft 1. Therefore, since the crawler 6 only changes this driving position (ground contact position) along the outer periphery of the crawler driving wheel 2, the perimeter does not change, and the crawler driving wheel 2 is rotated during the frame rotation. , Front and rear driven wheels 3F, 3R,
Alternatively, the wheels 4A, 4B, and 4C do not come off from the guides, and can be prevented from falling off.

The rear part of the transmission case 13 of the tractor 10 will be described. A cylinder case 32 containing a hydraulic cylinder 31 for lifting and lowering the work implement is provided at the rear of the transmission case 13. The lift arm 2 provided on the side of the case 32 by the expansion and contraction of the piston of the hydraulic cylinder 31.
3, 23 are rotated. The lift arm 23 on one side is provided with a lift arm angle sensor 33 for detecting the rotation angle. In addition, cylinder case 3
A tilt sensor 34 is provided in front of the vehicle 2 to detect the front-back tilt of the vehicle body, and the detected value is output to a controller 35 which is a control unit provided below the cockpit 19.

At the rear of the transmission case 13, a top link 36 and left and right lower links 37, 37 are provided.
And a work machine 24 is connected to the three-point link mechanism. The three-point link mechanism is connected to the left and right lift arms 23, 23, respectively, and the work machine 24 is moved up and down by rotating the lift arm 23 up and down. In the illustrated example, the rotary working machine is connected.

Next, the power transmission configuration of the tractor 10 will be described with reference to FIG. The rotational power from the engine 12 is intermittently connected by the main clutch 40 and is input to the forward / reverse switching device 41. And this forward / reverse switching device 4
At 1, the vehicle is branched into a traveling system power L1 and a PTO system power L2, and the traveling system power L1 is transmitted to the main transmission 42 and the auxiliary transmission 43. The traveling system power L1 is transmitted to the crawler 6 via the rear wheel differential device 44.
, And branches to a front wheel drive path L4 via a front wheel drive transmission device 45.

The front wheel drive transmission device 45 is composed of a double wet multi-plate hydraulic clutch 46, 47. When the rear hydraulic clutch 46 is pressed, the rotational power input from the auxiliary transmission 43 is transmitted at the same rotational speed. As a result, the peripheral speed of the crawler 6 becomes substantially the same as the peripheral speed of the front wheels 14, and the tractor 10 travels in a four-wheel drive mode. Further, when the front hydraulic clutch 47 is press-fitted, the rotation speed is increased to about twice that at the time of input, and the peripheral speed of the front wheel 14 is about twice the peripheral speed of the crawler 6. Thereby, the tractor 10
It is configured to make a small turn when turning. still,
When neither of the two hydraulic clutches 46 and 47 is in pressure contact with each other, the tractor 10 is configured to perform two-wheel traveling by the rear traveling device 2.

A transmission shaft 48 extending left and right from the rear wheel differential device 44 has brake discs 49 on the left and right sides, respectively.
, And the brake discs 49 are pressure-bonded by the operation of the brake hydraulic cylinder 50 to apply a brake to the crawler-type traveling device 7. Next, the operation of the attitude control of the crawler frame 7 will be described.

The controller 35 includes a CPU as an arithmetic processing unit for processing signals from various sensors and setting devices, a RAM for temporarily storing these sensor signals, a ROM for storing various control programs, and the like. Has become. The input section includes a steering angle sensor 18 and a control mode changeover switch 25 having a contact point of "forward raising mode", "free mode", and "full ground mode".
The potentiometer 22 of the position lever 21, the lift arm angle sensor 33, and the inclination sensor 34 are connected and provided. The output unit includes solenoids 55A and 55B of switching control valves for extending and retracting the hydraulic cylinder 30 for rotating the crawler frame 5, and a proportional pressure control valve for extending and retracting the piston of the hydraulic cylinder 31 for lifting and lowering the work implement. Solenoids 56 and 57, solenoids 58 and 59 of proportional pressure control valves for operating hydraulic cylinders 50 and 50 for applying a brake to the left and right drive shafts 1, and solenoids 60A and 60A of switching control valves for crimping the hydraulic clutches 46 and 47. 60B.

When the engine 12 of the tractor 10 is started, as shown in the flowchart of FIG. 6, the controller 35 sets the connection state of various switches and sensors,
The setting state is read (STEP 1). Then, from the detection of the inclination sensor 34, it is determined whether or not the inclination angle of the vehicle body is equal to or more than a predetermined value (STEP 2). If the determination is YES, it is determined that the vehicle is running on an incline or on a muddy work place and the vehicle body is in an upward state.
Then, the solenoid 55A of the switching control valve is energized to shorten the piston of the hydraulic cylinder 30 (the state shown by the dashed line in FIG. 1).

Thus, the contact point between the front wheel 1 and the crawler 4
The distance from the center of the contact surface 7 increases, and the position of the center of gravity of the vehicle body moves to the front side. Therefore, the shared load of the front wheel 1 is increased, and this lifting can be prevented, and the vehicle can travel safely even on a slope or a muddy work place. Also, STE
If the determination in P2 is NO, the process proceeds to STEP4, where the state of the control mode switch 25 is determined. Here, if the setting of this mode is “forward raising mode”, the aforementioned S
The processing of TEP3 is performed (C in FIG. 7). Thus, during high-speed running on a road or the like, the ground contact surface of the crawler 47 is reduced, friction with the ground is reduced, and wear of the crawler 47 can be reduced as much as possible.

In the "free mode" (B in FIG. 7), the hydraulic cylinder 30 is held so as to freely swing without applying hydraulic pressure to the piston. This allows
The crawler frame 7 can rotate freely within the range of the elongated hole 7F of the mounting piece 7E. Further, in the case of the “entire grounding mode”, the solenoid 55B of the switching control valve
To extend the piston of the hydraulic cylinder 30 to the maximum and fix it (A in FIG. 7). As a result, the crawler frame 5 is pressed against the ground, the contact surface of the crawler 6 is maximized, and the traction force of the tractor 10 can be increased.

In the attitude control of the crawler frame 5 of the tractor 10 configured as described above, the contact position of the crawler 6, that is, the installation area can be changed according to the state of each field and the running state. Performance can be improved. Further, the STEP3, STEP5, STE
When the process in P6 is completed, the controller 35 determines the turning state of the vehicle body from the steering angle sensor 26. Here, if the vehicle body is in a turning state, the turning control shown in FIG. 8 is executed, and the process returns.

The turning control of the tractor 10 first detects the operating speed of the steering handle 17 per unit time, and if the operating speed is equal to or higher than a preset operating speed, the turning of the tractor 10 in the field (headland) (Turning), the solenoid 56A of the proportional pressure control valve is energized, and the work implement 24 is raised (STEPs 1 and 2). Thereafter, the solenoid 58 (59) of the proportional pressure control valve is energized to apply a brake to the drive shaft 1 of the crawler 6 inside the turn (STEP 3). Further, the solenoid 60B of the switching control valve is continuously energized to switch the front wheel 14 to the speed-up state, and the solenoid 55A of the switching control valve is energized to lift the front portion of the crawler frame 7 around the drive shaft 1 ( (STEP 4).

Thus, conventionally, when the working machine is raised (especially immediately after the lifting), the shared load of the front wheels 14 is reduced, and the front wheels 1
To solve the problem that traction force cannot be obtained by driving 4
Here, by changing the contact surface of the crawler 6 to the rear as much as possible, it is possible to increase the shared load of the front wheels 14. Therefore, the tractor 10 can increase the traction force of the front wheel 14 and make it easier to make a small turn, as compared with the case where the tractor 10 turns with the crawler 6 in full contact with the ground. Further, the ground contact area of the crawler 6 is reduced, so that the roughness of the field can be reduced.

[Brief description of the drawings]

FIG. 1 is a partial front view of a rear traveling device.

FIG. 2 is an overall side view of the tractor.

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

FIG. 4 is a diagram showing a transmission mechanism of the tractor.

FIG. 5 is a block diagram showing connection of a controller.

FIG. 6 is a flowchart showing an outline of a control program for crawler frame attitude control.

FIG. 7A is a diagram showing a tip of a piston of a hydraulic cylinder in a “full contact mode”. (B) The figure which shows the piston front-end | tip part of the hydraulic cylinder at the time of "free mode." (C) The figure which shows the piston front-end | tip part of the hydraulic cylinder at the time of "front raising mode."

FIG. 8 is a flowchart showing an outline of a control program for turning control.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Drive shaft 2 Crawler drive wheel 3 Follower wheel 4 Roller wheel 5 Crawler frame 6 Crawler 7 Crawler traveling device 10 Tractor

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Nozomu Katakami 1-Yachikura, Tobe-cho, Iyo-gun, Ehime Prefecture Iseki Agricultural Machinery Co., Ltd.

Claims (1)

[Claims] 1. A pair of left and right drive shafts 1, 1 protrude from the side of a vehicle body. Crawler drive wheels 2, 2 are provided on the drive shafts 1, 1, and a driven wheel 3 is provided below the drive shafts 1, 1. Or a supporting member 5 for supporting the rolling wheels 4 is arranged, and a crawler 6 is stretched between the driving wheels 2 and 2 for the crawler and the driven wheels 3 or the rolling wheels 4 to perform a crawler-type traveling device. 7 or the driven wheels 3.
A crawler-type traveling device for a working vehicle, wherein a support member 5 for supporting... Is mounted rotatably around the axis of the drive shafts 1 and 1.