JPH05345580A - Tread changing structure for work vehicle - Google Patents

Abstract

PURPOSE:To protect members which change and adjust the tread between crawler running units from collision with others, wind and rain and the like, and thereby enable them to be excellent in durability. CONSTITUTION:Each screw shaft 13 which is supported on each truck frame 7 in such a way that it can be rotatably operated in a state that movement is limited in the distance direction between the truck frame 7 of each crawler running unit 1 and a car body fixed section 2, is threadedly inserted into the other end section of each cylindrical member 11 one end of which is supported on the car body fixed section 2 in such a way as to freely appear frequently, and concurrently the other end section of each cylindrical member 11 is so constituted as to be inserted in each truck frame 7 across a range from the maximum disappeared position of each screw shaft 13 to its maximum appeared position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tread changing structure for a work vehicle equipped with a crawler traveling device such as a backhoe.

[0002]

2. Description of the Related Art Conventionally, as a tread changing structure for a work vehicle of this type, as disclosed in, for example, Japanese Utility Model Laid-Open No. 3-55391, a track frame and a body fixing portion of a pair of left and right crawler traveling devices. The cylindrical frame that is connected in the left-right direction across the and is configured as a double cylinder that is slidably fitted to each other in the lateral direction. A screw shaft and a top member screwed to the screw shaft are separately provided in one and the other of the frames of the heavy cylinder so as to be exposed to the outside, and the double operation is performed by rotating the screw shaft. It is known that the frame of the cylinder is configured to expand and contract.

[0003]

However, in the above-mentioned conventional structure, since the members such as the screw shafts for changing and adjusting the tread of the crawler traveling device are exposed to the outside, the work vehicle for earthworking. In agricultural work vehicles such as trucks and combine harvesters, there is a high possibility that the tread change adjustment member will collide with the ground or obstacles due to swaying of the machine due to unevenness of the running place, and the tread change adjustment member is exposed to rain and dew. However, there is a problem in that it is easily rusted and damaged by being damaged. The present invention has been made in view of the above circumstances, and is a work vehicle capable of protecting a member for adjusting a tread of a crawler traveling device from collision with another object, rain dew, etc., and having high durability. The purpose is to provide a tread modification structure.

[0004]

In order to achieve the above object, the tread changing structure for a work vehicle according to the present invention is a state in which movement of the track frame of the crawler traveling device and the body fixing portion is restricted in the perspective direction. A screw shaft rotatably supported by the track frame is screwed into a tubular member supporting one end of the machine body fixing portion so that the screw shaft can be retracted and retracted from the other end, and the screw shaft is protruded maximum from the maximum retracted posture. The other end of the tubular member is configured to be inserted into the track frame over the posture. The actions and effects of this characteristic configuration are as follows.

[0005]

In other words, the screw shaft rotatably supported by the track frame in a state where movement of the track frame and the machine body fixing portion is restricted in the perspective direction is supported by the tubular member having one end supported by the machine body fixing portion and the other end. Since the screw shaft is screwed into and out of the unit, the track frame can be moved to and away from the machine body fixing unit by rotating the screw shaft, and the tread can be adjusted and adjusted. And
Since both the screw shaft and the screwed portion of the screw shaft of the tubular member are inserted into the track frame from the maximum retracted posture to the maximum projected posture of the screw shaft, they are not exposed to the outside.

[0006]

Therefore, according to the present invention, the track frame is used as a member for protecting the screw shaft or the like for changing and adjusting the tread from collision with other objects or rain and dew. Rust is suppressed and durability is improved, and since it also serves as a protective member for the track frame, it is not necessary to provide a special member for protecting the screw shaft, etc., so the structure is simple and the number of parts can be reduced. There are advantages.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 5 shows a backhoe as an example of the work vehicle. The backhoe includes a pair of left and right crawler traveling devices 1, 1, a machine base 2 supported by the crawler traveling devices 1, 1, and a swivel base 3 supported by the machine base 2 so as to be rotatable about a vertical axis. And a driving unit 4, a driving unit 5, and a backhoe working device 6 mounted on the swivel base 3.

As shown in FIGS. 1 and 2, the track frame 7 of the crawler traveling device 1 is composed of a frame member having a U-shape facing downward in a vertical sectional front view, and the machine base 2 serving as a machine body fixing portion. Square pipe frames 9 and 9 fixed to the track frame 7 are slidably fitted in the left and right directions to a pair of rectangular tubular frame members 8 and 8 provided in front and rear. Then, the pair of front and rear rectangular tubular frame members 8,
In the front-rear intermediate position between 8 and 9, a tubular member 11 made of a round pipe is pivotally supported by a pin 10 on a lateral side portion of the machine base 2 and is opposed to a free end portion of the tubular member 11. A pair of front and rear ears 11a, 11a are provided in a rectangular shape so as to project.
A vertically long oval through hole 12 through which the ears 11a, 11a can be inserted is formed, and the free end of the tubular member 11 is inserted into the track frame 7 through the through hole 12. That is, the free end portion of the tubular member 11 is inserted into the through hole 12 of the track frame 7 before being pivotally supported by the pin 10, and then the tubular member 11 is rotated about 90 degrees to the machine base 2 with the pin 10. It is pivotal. Therefore, in this state, the ears 11a, 11a are regulated in contact with the inner side wall 7A of the track frame 7 and prevented from coming off. A female screw portion 11b into which a screw shaft 13 described later is screwed is formed on the inner peripheral portion of the free end portion of the tubular member 11.

As shown in FIGS. 1 and 2, the inner side wall portion 7A of the track frame 7 is reinforced near the formation of the through hole 12 and the outer side wall portion 7B of the track frame 7 away from the machine base 2. The frame 14 is installed, and the screw shaft 13 is inserted into the track frame 7 through the reinforcing frame 14 that is bent to form an L shape in plan view and the hole formed in the outer side wall portion 7B. Has a threaded portion on the female screw portion 11b of the tubular member 11. The screw shaft 13 is a hexagonal bolt having a head portion 13A formed in a hexagonal shape. A flange 13B is formed in a brim shape at the base portion of the head portion 13A, and the flange 13B is formed from the reinforcing frame 14 and the outside from the track. It is rotatably sandwiched by a contact plate 15 bolted to the frame 7. As a result, the screw shaft 13 itself is restricted from moving in the perspective direction between the track frame 7 and the machine base 2. Further, the stopper member 16 formed of a plate member having a hexagonal hole 16a that engages with the hexagonal portion of the head portion 13A of the screw shaft 13 is provided with the hexagonal hole 16a being engaged with the head portion 13A of the screw shaft 13. It is fixed to the track frame 7 with screws 24. The stopper member 16 can also be used as a wrench member for rotating the screw shaft 13, and in the state where the thumbscrew 24 is removed, the bent arm portion of the stopper member 16 is turned upside down. It is used in the inverted state.

With the above structure, when the distance between the left and right crawler traveling devices 1 and 1 is changed and adjusted, the screw shaft 13 is rotated from the outside of the machine by the stopper member 16 or the like, as described above. The shaft 13 is moved in and out of the tubular member 11, and the track frame 7 is displaced in the left-right direction by being guided by the relative sliding movement of the square tubular frame member 8 and the square pipe frame 9 with respect to the machine base 2. Will be done. Then, as described above, the stopper members 16 are attached to the track frame 7 while being restricted so that the screw shaft 13 does not rotate, so that the left and right crawler traveling devices 1 and 1 are maintained at a predetermined interval. .. Incidentally, when the distance between the crawler traveling devices 1 and 1 is changed and adjusted as described above, the crawler traveling devices 1 and 1 are floated above ground.

Next, a structure for changing the horizontal length of the dozer 17, which is mounted in the front of the machine base 2 so as to be vertically swingable, will be described. As shown in FIGS. 1 and 3, the dozer 17 includes a pair of left and right arms 1 in which a main dozer portion 18 is connected to a machine base 2.
It is supported by 9 and 19 so as to be vertically swingable, and is configured to be moved up and down by a hydraulic cylinder (not shown). Then, on the back of the left and right end portions of the main dozer portion 18,
A cylindrical guide member 20 along the left-right direction is connected in a state of being connected to the left and right arms 19, and an inner fitting member 21 slidably fitted in the cylindrical guide member 20 in the left and right directions. An auxiliary dozer portion 22 that is movable integrally is connected to the inner fitting member 21. The tubular guide member 20 and the inner fitting member 21 can be fixed by bolts 23 at arbitrary expansion and contraction positions. The bolt 23 can be rotated using the stopper member 16, so that the left and right lengths of the dozer 17 can be adjusted.
It is performed according to the interval change of 1.

It should be noted that reference numerals are given in the claims for convenience of comparison with the drawings, but the present invention is not limited to the configuration of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a partially cutaway plan view showing a traveling structure of a backhoe.

FIG. 2 is a vertical cross-sectional rear view showing the tread changing structure of the crawler traveling device.

FIG. 3 is an exploded perspective view showing a stretchable structure of a dozer.

FIG. 4 is a side view showing the relationship between the tubular member and the through hole of the track frame.

FIG. 5 is an overall side view showing a backhoe.

[Explanation of symbols]

 1 Crawler traveling device 2 Body fixing part 7 Track frame 11 Cylindrical member 13 Screw shaft

Claims (1)

[Claims] 1. A screw rotatably supported on the track frame (7) in a state where movement of the track frame (7) of the crawler traveling device (1) and the machine body fixing portion (2) is restricted in a perspective direction. The shaft (13) is screwed into the tubular member (11) whose one end is supported by the machine body fixing part (2) so as to be retractable from the other end, and the screw shaft (13)
The tread changing structure of the working vehicle configured such that the other end of the tubular member (11) is inserted into the track frame (7) from the maximum retracted posture to the maximum projected posture.