JPH0326743B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a front loader that allows a working tool to rotate through an angle greater than the angle corresponding to the stroke of a working tool cylinder.

(Prior art) Generally, in a front loader, the base of the boom is pivoted to the upper end of the mounting frame, a bucket as a working tool is pivoted to the tip of the boom, and a fixed cylinder mounting plate is attached to the middle part of the boom in the longitudinal direction. A boom cylinder and a bucket cylinder are provided between the mounting frame and the bucket, and the rotation angle of the bucket is a constant angle determined by the stroke of the bucket cylinder.

(Problem to be solved by the invention) In order to more reliably perform the scooping and dumping operations of the bucket, the rake angle (upward rotation angle) and dump angle (downward rotation angle) should be made larger. However, since the stroke of the bucket cylinder is constant, increasing the rake angle will decrease the dump angle, and increasing the dump angle will decrease the rake angle, so it is difficult to increase both angles, and the rake and dump operations One of them had been sacrificed.

(Means for Solving the Problems) The present invention solves the problems of the prior art by attaching the cylinder mounting plate 10 to which the boom cylinder 7 and the work tool cylinder 9 are connected at a certain angle in the middle of the boom 6. By making it rotatable, all of these problems can be solved.

That is, the specific configuration of the problem solving means of the present invention is as follows:
A cylinder mounting plate 10 is provided in the middle of a boom 6 that is pivotably supported on the upper end of the mounting frame 5 so as to be able to move vertically.
A boom cylinder 7 is provided between the cylinder mounting plate 10 and the mounting frame 5, and a work tool cylinder 9 is provided between the cylinder mounting plate 10 and a work tool 8 that is pivotably supported on the tip of the boom so as to be able to move up and down. In the front loader, the cylinder mounting plate 10 is located on the horizontal axis at a position below the center line G of the boom cylinder 7 and below the center line H of the work tool cylinder 9, with respect to the boom 6 with the work tool in contact with the ground. 16 so as to be rotatable back and forth, and a rotation angle setting means for setting the rotation angle range of the cylinder mounting plate 10 is provided between the cylinder mounting plate 10 and the boom 6. shall be.

(Function) As shown in FIG. 1, when the boom cylinder 7 is extended with the horizontal shaft 16 located below both the center lines G and H of the boom cylinder 7 and the work tool cylinder 9, the cylinder mounting plate 10 is The work implement 8 is rotated in the dumping direction by rotating in the counterclockwise direction in FIG. When the boom cylinder 7 is retracted, the cylinder mounting plate 10 is rotated clockwise in FIG. 1 about the horizontal shaft 16, and the work tool 8 is rotated in the rake direction. Therefore, the rotation range of the work implement 8 set by the work implement cylinder 9 is limited to the range of rotation of the work implement 8 set by the work implement cylinder 9.
deviates in the dumping direction and the scooping direction by
Expand the dumping and scooping ranges.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

In Figs. 1 to 3, 1 is a tractor, and the rear part of the tractor is equipped with a three-point linkage mechanism 2.
A hydraulic system 3 for lifting and lowering the work machine is installed.

Reference numeral 4 designates a bucket-type front loader for tractor equipment, which includes a pair of left and right booms 6 supported rotatably around a horizontal shaft 13 at the upper end of a mounting frame 5 fixed to the tractor 1, and the booms 6 swinging above. Left and right 1
A pair of boom cylinders 7 and a horizontal shaft 14 at the tip of the boom
It has a working tool 8, exemplified by a bucket that is rotatably supported, and a pair of left and right working tool cylinders 9 for moving the working tool 8 up and down.

A downwardly protruding bearing portion 15 is provided in the middle of each of the left and right booms 6 by bulging or by welding a separate member.
A cylinder mounting plate 10 is pivotally supported on this bearing portion 15 via a horizontal shaft 16, and one end of the boom cylinder 7 and the base of the work implement cylinder 9 are pivotally connected to this cylinder mounting plate 10. The left and right cylinder mounting plates 10 are connected by a reinforcing pipe 17. That is, the boom cylinder 7 is pivotally connected at its base end to the midway point in the vertical direction of the mounting frame 5 via a pin 7b, and at its distal end to the rear part of the cylinder mounting plate 10 via a pin 7a. The proximal end of the cylinder 9 is pivotally connected to the front of the cylinder mounting plate 10 via a pin 9a, and the distal end thereof is pivotally connected to the rear of the working tool 8 and above the horizontal shaft 14 via a pin 9b. Then, the cylinder mounting plate 1 is placed against the boom 6 with the work tool 8 in contact with the ground.
The horizontal axis 16 that pivots on the boom cylinder 7 is located forward and lower than the center line G of the boom cylinder 7 (passes through the pins 7a and 7b), and .) is located posteriorly and inferiorly.

Reference numerals 18 and 19 indicate stoppers that restrict the rotation of the cylinder mounting plate 10. When the cylinder mounting plate 10 is in contact with the first stopper 18, the boom cylinder 7
The extension force pushes down the boom 6 and the second stopper 19
When in abutment, the tension force of the implement cylinder 9 causes the implement 8 to pivot downward.

The stoppers 18 and 19 are connected to the cylinder mounting plate 10.
Instead of this, an arc-shaped elongated hole centered on the horizontal axis 16 is formed in the cylinder mounting plate 10, and a pin that passes through the arc-shaped elongated hole is formed in the boom 6. It may be configured by fixing it.

Next, the working operation of the front loader 4 of the above embodiment will be explained.

With the boom 6 lowered and the bottom surface of the work tool 8 in contact with the ground in the solid line state A in FIG. 1, the tractor 1 is moved forward and dirt is scooped out with the work tool 8. In this state A, the cylinder mounting plate 10 is at the rear position α in contact with the second stopper 19, and the work tool cylinder 9 has moved relatively backward. When the work tool cylinder 9 is retracted from this state A, The work implement 8 can be rotated upward to the state B shown in two-dot chain line in FIG. 1 (the position indicated by the upper dot line in FIG. 3), and by rotating upward, the amount of dirt scooped can be increased.

When the boom cylinder 7 is extended from the state B, the cylinder mounting plate 10 is removed before the boom 6 is raised.
rotates forward around the horizontal axis 16 and the first stopper 18
The tool 8 moves from the state B to the state C (two-dot chain line in the upper part of FIG. 3), where the rake angle is small, with the tool cylinder 9 interposed like a connecting rod. At this time, since the earth and sand are deep inside the working tool 8, there is no need to worry about it spilling out.

When the boom cylinder 7 is further extended from the state B where the cylinder mounting plate 10 is in contact with the first stopper 18, the boom 6 rotates upward around the horizontal shaft 13,
The state is shown by the two-dot chain line in FIGS. 1 and 2. The tractor 1 is driven in this raised state to move the work implement 8 to another position or above the loading platform of the carrier.

When the work tool 8 is in state C after scooping up the earth and sand and the work tool cylinder 9 is extended, the base of the work tool cylinder 9 has moved to the forward position β, so it rotates downward to state D (dumping operation). This state D is the position shown by the solid line in FIG. 2 (the position shown by the lower dotted line in FIG. 3).

After the earth and sand are discharged from the working tool 8 by the dumping operation, the tractor 1 is driven to return the front loader 4 to the scooping work position. Then, while the work tool 8 remains in state D, the boom cylinder 7 is contracted by the weight of the boom 6 and/or the oil pressure, and the boom 6 is lowered.

As the boom 6 is lowered, the tip of the work tool 8 first comes into contact with the ground. After the tip of the work tool 8 touches the ground, it rotates relative to the boom 6 so that the rear part lowers, and the boom 6 further descends. Work tool 8 at this time
This rotation is allowed by the cylinder mounting plate 10 rotating from the front position β to the rear position α via the work tool cylinder 9, and the work tool 8 changes from state D to state E. The work implement 8 can be shifted from state E to state A by contracting the work implement cylinder 9 and pivoting upward so that its bottom surface is parallel to the ground.

That is, in the embodiment described above, the stroke of the work tool cylinder 9 remains unchanged, but as the cylinder mounting plate 10 rotates in the front-rear direction, the work tool cylinder 9 itself moves back and forth, as shown in FIG. Then, the rotation angle range θ of the work tool due to the operation of the work tool cylinder 9 changes its position up and down, and during scooping work it becomes the upper range θU and the rake angle θS increases, and during dumping work it changes to the lower range. As θL becomes larger, the dump angle θR becomes larger, and the respective working capacities can be expanded.

(Effects of the Invention) As the cylinder mounting plate 10 can be rotated around the horizontal axis 16 with respect to the boom 6 within the range set by the rotation angle setting means by the extension operation of the boom cylinder 7, the work is easier. The vertical movement range of the work tool 8 by the tool cylinder 9 can be shifted downward when the boom cylinder 7 is extended and upward when it is retracted, so that even if the stroke of the work tool cylinder 9 is constant,
The scooping operation range and dumping operation range of the work tool 8 can be increased to improve work performance.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; FIG. 1 is an overall side view, FIG. 2 is an explanatory diagram of the overall operation, and FIG. 3 is an explanatory diagram of the main part of the operation. 1...Tractor, 4...Front loader, 5...
...Mounting frame, 6...Boom, 7...Boom cylinder, 8...Work tool, 9...Work tool cylinder,
10... Cylinder mounting plate, 18... First stopper, 19... Second stopper, A, B, C, D, E
...condition, θU...rake operating range, θL...dump operating range, θS...rake angle, θR...dump angle.

Claims (1)

[Scope of Claims] 1. A cylinder mounting plate 10 is provided in the middle of the boom 6 which is pivotably supported on the upper end of the mounting frame 5 so as to be able to move up and down, and the boom cylinder 7 is provided between the cylinder mounting plate 10 and the mounting frame 5. In a front loader in which a work tool cylinder 9 is provided between a work tool 8 which is pivotably supported at the tip of the boom so as to be able to move up and down and a cylinder mounting plate 10, the cylinder mounting plate 10 is attached to the boom when the work tool is in contact with the ground. 6, the cylinder mounting plate 10 and the boom are 6, a rotation angle setting means for setting a rotation angle range of the cylinder mounting plate 10 is provided.