JPH0522008Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention relates to a lift rod adjustment operation device in a three-point linkage mechanism for a tractor with a cabin.
This is intended to reduce the vibration noise of the lift rod that is transmitted into the cabin.

(Prior Art) In a tractor, a pair of left and right lower links of a three-point linkage mechanism and a pair of left and right lift arms of a hydraulic system are connected by a lift rod, and the hydraulic system connects a pair of left and right lower links of a three-point linkage mechanism to a pair of left and right lift arms of a hydraulic system. It is designed to raise and lower a working machine attached to a three-point linkage mechanism.

One of the pair of left and right lift rods is extendable and retractable by an extendable adjustment section, and is used to adjust the relative vertical positions of the left and right lower links. In the case of a tractor inside the cabin, the operating rod is guided further toward the cabin so that adjustment operations can be performed inside the cabin.

(Problems that the invention aims to solve) However, conventionally, the operating rod has a nested structure with an inner and outer rod, and the inner and outer rods are in direct contact with each other and slide, resulting in seizures, foreign matter contamination, etc. Therefore, when the gap between the inner and outer rods was increased, vibrations from the lift rod were transmitted to the cabin via the operating shaft, causing large noise in the cabin.

(Means for Solving the Problems) The present invention is intended to solve such conventional problems, and as a specific means for that purpose, the lift arm 8 of the hydraulic device 7 for lifting and lowering the work machine and the three-point The lower link 6 of the link mechanism 4 is
An operating rod 27 is provided astride the lift rod 9 and the cabin 18, and the operating rod 27 is connected to the loft rod 9 having a loft rod 9 having an inner and outer rod 29, and is connected to the outer rod 29.
28, a vibration isolating material 38 is inserted between the inner rod 29 and outer rod 28 of the operating rod 27 and on the opening end side of the nest from the longitudinal direction of the rod so that they do not come into contact with each other. A positioning part 41 which is removably interposed and has a male and female structure is provided between the vibration isolating material 38 and the outer rod 28, and the positioning part 41 is provided between the vibration isolating material 38 and the outer rod 28 in the longitudinal direction of the rod via the positioning part 41. It is characterized by preventing movement.

(Function) When adjusting the extension/retraction of the lift rod 9, the cabin 1
The expansion/contraction adjustment unit 10 is operated from inside the operating rod 27 through the operating rod 27, and the inner and outer rods 29,
There is a vibration isolator 38 between the lift rods 9 and 28, which prevents direct contact between the two, so the vibration isolators 38 can block the transmission of vibrations from the lift rod 9 into the cabin 18. In addition, since the vibration isolating material 38 is interposed on the nested opening end side, the vibration isolating material 38 acts as a plug for the opening and prevents rust due to sliding, resulting in smooth sliding and prevention of rattling. can be achieved.

Further, the relative movement of the vibration isolator 38 and the outer rod 28 in the longitudinal direction of the rod is prevented by the positioning portion 41, and the vibration isolator
8's accidental omission is prevented.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

In FIG. 2, 1 is a tractor body, and 2 is a rear wheel, which is attached to both sides of the tractor body 1 via a rear axle case 3 and the like. Reference numeral 4 denotes a three-point link mechanism, which is used to attach a working machine to the rear of the tractor body 1, and is composed of a top link 5 and a pair of left and right lower links 6. Reference numeral 7 denotes a hydraulic system for lifting and lowering the working machine, which has a pair of left and right lift arms 8, and is mounted on the rear of the tractor body 1. Each lift arm 8 is connected to a lower link 6 via a lift rod 9.
Therefore, a working machine (not shown) attached via the three-point linkage mechanism 4 can be raised and lowered by the hydraulic system 7. Of the pair of left and right lift rods 9, one of the lift rods 9 is provided with a telescoping adjustment section 10 as shown in FIG. 1, so that it can be freely adjusted.

That is, this has a screw shaft 11 and a screw tube 12 fitted onto the screw shaft 11, and the screw shaft 11 can be rotated by a rotation shaft 16 via bevel gears 14 and 15 in a case 13. It's getting old.

Furthermore, in FIG. 2, 17 is a bonnet;
A cabin 8 is mounted on the tractor body 1 and integrally includes a fender portion 19 corresponding to the rear wheel 2, a floor plate 20 covering the tractor body 1, a rear wall plate 21 rising from the rear end, etc. . The cabin 18 is attached to a bracket 22 provided on both sides of the central portion of the tractor body 1 and to the rear axle case 3 behind the bracket 22 via vibration isolators 23 and 24.

25 is a steering handle, and 26 is a driver's seat, which are provided on the side of the cabin 18. Reference numeral 27 denotes an operating rod for operating the rotating shaft 16, and as shown in FIGS. 4 to 6, it is equipped with a square tube-shaped outer rod 28 and a square rod-shaped inner rod 29 fitted inside the rod. It has a nested structure. The outer rod 28 is a protrusion 3 formed on the rear wall plate 21 at the rear corner of the cabin 18, as shown in FIG.
0 vertically and is rotatably and swingably supported via the ball receiver 30A. Further, the upper end of the outer rod 28 has a handle 31 for rotation operation, and when the handle 31 is not operated, the elastic band 3
It is hooked up to 2. The band 32 is made of rubber or the like, and is connected to the end of the rear wall plate 21 with a stopper 33 as shown in FIGS.
A hole 32B having a slightly smaller diameter than the grip portion 31A of the handle 31 is formed.

The stopper 33 is pivotally attached to the rear wall plate 21 via a pivot 34, and the base end of the band 32 is attached to the stopper 33 with the stopper 3.
5 and fixed with bolts and nuts 36.

The stopper 33 may be one that extends horizontally as shown in FIG. 9, or one that extends upwardly as shown in FIG. 10.

The lower end of the inner rod 29 is connected to the rotating shaft 16 via a universal joint 37, as shown in FIG. Between the inner rod 29 and the outer rod 28, a vibration isolating material 38 is inserted and removably inserted in the longitudinal direction of the rod from the lower end side of the outer rod 28 to prevent direct metal contact between the two. It is interposed on the open end side of the nest.

The vibration damping material 38 may be made of plastic or other elastic cushion material, or metal. The vibration isolating material 38 has a rectangular C-shaped cross section as shown in FIGS. Here, the protrusion 39 and the hole 40 constitute a positioning part 41 having a male-female structure, and prevent relative movement between the vibration isolating material 38 and the outer rod 28 in the rod longitudinal direction.

As shown in FIG. 6, the protrusion 39 has a taper 3 on the insertion side (upper side in FIG. 6) of the vibration isolator 38 for guiding insertion.
9A and a so-called trapezoidal cross section in which a detent 39B is formed at the tapered base is advantageous.

Note that the male and female structure of the positioning part 41 is opposite to that shown in the drawings, with the protrusion 39 being connected to the outer rod 28 and the hole 40 being connected to the vibration isolating material 38.
It does not matter if it is formed as follows.

In the above configuration, a pair of left and right lower links 6
When adjusting the relative vertical position of the handle 31, the handle 31 is rotated after the handle 31 is released from the band 32. Then, the rotation shaft 16 is moved through the outer rod 28, vibration isolating material 38, and inner rod 29 of the operation rod 27.
rotates, the screw shaft 11 rotates via the bevel gears 15 and 14, and the screw tube 12 that is screwed therewith expands and contracts up and down. After adjustment, hold the knob 32A and pull the band 32, pass the handle 31 through the hole 32B, and stop the operating rod 27 from rotating.

When the work machine is raised or lowered, the inner rod 29 moves in and out relative to the outer rod 28, and the operating rod 27 swings about the ball receiver 30A as a fulcrum, but since the band 32 is an elastic body, , there is no problem.

Slight vibrations are always generated in the lift rod 9 during operation of the engine or during work with a working machine. However, there is a vibration isolating material 38 between the inner rod 29 and the outer rod 28, which prevents the inner and outer rods 29 and 28 from coming into direct contact with each other, so the lift rod 9
Most of the vibrations from the side can be cut off by the vibration isolating material 38, and the generation of noise on the side of the cabin 18 can be prevented. The vibration isolating material 38 also has the effect of smoothing the sliding movement of the inner rod 29.

Furthermore, the vibration isolating material 38 and the outer rod 28 are connected to the positioning part 4.
1 prevents relative movement and prevents the vibration isolating material 38 from accidentally coming off even if subjected to vibration, etc., and the vibration isolating material 3
8 is interposed at the end of the nested opening of the inner and outer rods 29 and 28, so it acts as a plug for the opening, preventing foreign matter from entering the deep part of the nesting, and preventing rust. It prevents rattling while ensuring smooth sliding.

(Effects of the invention) According to the invention, a vibration isolating material is interposed between the inner and outer operating rods to prevent them from coming into contact with each other.
It can cut off vibrations transmitted from the lift rod to the cabin side and reduce noise on the cabin side.

In addition, the vibration isolating material and the outer rod are prevented from relative movement in the longitudinal direction of the rod by the male-female structure positioning part.
It can prevent the vibration isolating material from coming off accidentally due to vibration, etc.

Since the vibration isolating material is interposed at the ends of the nested openings of the inner and outer rods, it acts as a plug for the openings, preventing foreign matter from entering the inner part of the nesting, and preventing rust from occurring. It ensures smooth sliding of the inner and outer rods and prevents rattling.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which Fig. 1 is a configuration diagram of an adjustment section, Fig. 2 is a partially cutaway side view of a tractor with a cabin, and Fig. 3 is a perspective view of the inside of the cabin.
Fig. 4 is a longitudinal sectional view of the positioning part, Fig. 5 is a sectional view taken along the line A-A in Fig. 4, Fig. 6 is a longitudinal sectional view showing the second embodiment of the positioning part, and Fig. 7 is a plane of the band part. figure,
FIG. 8 is a sectional view of the same, and FIGS. 9 and 10 are elevational views showing two examples of the band portion. 1... Tractor body, 4... Three-point linkage mechanism,
6...Lower link, 7...Hydraulic system, 8...Lift arm, 9...Lift rod, 10...Telescopic adjustment section, 18...Cabin, 27...Operation rod, 2
8... Outer rod, 29... Inner rod, 38... Vibration isolating material, 4
1...Positioning section.

Claims (1)

[Claims for Utility Model Registration] A lift arm 8 of a hydraulic device 7 for lifting and lowering a working machine and a lower link 6 of a three-point linkage mechanism 4 are connected by a lift rod 9 having a telescopic adjustment portion 10, and the telescopic adjustment portion 10 is An operating rod 27 that is operated from inside the cabin 18 is provided across the lift rod 9 and the cabin 18, and this operating rod 27 has a nested structure of inner and outer rods 29 and 28 that slide relative to each other in the longitudinal direction of the rod. In this case, a vibration isolating material 38 is interposed between the inner rod 29 and the outer rod 28 of the operating rod 27 and on the side of the nested open end so that they do not come into contact with each other, so that the vibration isolating material 38 can be inserted and removed from the longitudinal direction of the rod. A positioning part 41 having a male-female structure is provided between the vibration material 38 and the outer rod 28, and the relative movement of the vibration isolation material 38 and the outer rod 28 in the longitudinal direction of the rod is prevented via the positioning part 41. An adjustment operation device for a lift rod in a three-point linkage mechanism for a tractor with a cabin, characterized by: