JP2010018952A - Front loader - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make the uppermost ascent position of a boom higher by the amount of upward movement of a base by moving the base of the boom upward when the boom is elevated from the grounded state of a working tool. <P>SOLUTION: The base 5a of the boom 5 is connected via a pivot 4 to a mast 3 which is mounted on a traveling vehicle body 2; a boom cylinder 6 for hoisting/lowering the boom 5 is provided between the mast 3 and the boom 5; and the working tool 7 is provided at the leading end of the boom 5. A pivot hole 8 for the penetration of the pivot 4 of the mast 3 is formed in a vertically long shape so as to allow the upward movement of the base 5a of the boom 5 when the boom 5 is elevated from the grounded state of the working tool 7. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a front loader mounted on a traveling vehicle such as a tractor.

In this type of conventional technology, for example, as disclosed in Patent Document 1, a pair of left and right mounting frames are mounted on a pair of main frames provided on both sides of a vehicle body so as to be movable up and down, and upper ends of these mounting frames In addition, the base side of a pair of left and right wrist arms provided with a working portion at the tip is pivotally supported in the vertical direction so that each wrist arm and each mounting frame are connected by a pair of left and right lift cylinders, A pair of left and right pairs of base arms, which extend from the mounting frame of each wrist arm to the side opposite to the working part side, and the lower part of each main frame are moved so that the mounting frame moves up and down as the wrist arm rotates. There is an apparatus for increasing the amount of lift of a working unit such as a front loader (a claim for a utility model registration) characterized by being connected by a connecting link.
Japanese Utility Model Publication No. 61-20128

The prior art switches the pivot point on the base side of the wrist arm between the lower position and the upper position. The pivot point does not move up and down during the vertical movement of the wrist arm, and the pivot point is changed in the vertical position. To make it possible, it is necessary to equip the main frame with the mounting frame so that it can move up and down, extend the base end of the wrist arm backward, and connect the base end to the lower part of each main frame with a connecting link The structure is complicated.
An object of the present invention is to provide a front loader that can solve such problems of the prior art.

  It is an object of the present invention to provide a front loader in which a boom base moves up when the boom is lifted from a state where a work tool is grounded, and the highest lifted position of the boom can be increased by an amount corresponding to the upward movement of the base. Objective.

Specific means for solving the problems in the present invention are as follows.
First, a base 5a of a boom 5 is connected to a mast 3 attached to the traveling vehicle body 2 via a pivot shaft 4, and a boom cylinder 6 for raising and lowering the boom 5 is provided between the mast 3 and the boom 5. In the front loader provided with the work tool 7 at the tip of the boom 5,
A shaft hole 8 for penetrating the pivot shaft 4 of the mast 3 is formed vertically long so as to allow the base 5a of the boom 5 to move upward when the boom 5 is raised from the state where the work tool 7 is grounded. It is characterized by being.

Secondly, the mast 3 has a receiving means 9 for restricting the upward movement of the pivot shaft 4 to support the rearward load of the boom 5 in a state where the work tool 7 is grounded in the lower portion 8a of the shaft hole 8. It is characterized by.
Thirdly, the receiving means 9 is formed in the lower part 8a of the shaft hole 8, and is an arcuate long hole wall through which the curvature center line R passes through the rear side from the tip of the working tool 7, or an inclined shape through which a vertical line passes. It is formed by a long hole wall.
[Action]
The front loader having the above features has the following effects.

When the boom cylinder 6 is extended from the state in which the work tool 7 is grounded and the boom 5 is raised, the boom 5 is raised on the base 5a side because the work tool 7 side is heavy around the connection point of the boom cylinder 6.
Since the shaft hole 8 for penetrating the pivot shaft 4 of the mast 3 is long in the vertical direction, the base portion 5a of the boom 5 moves upward with respect to the mast 3 together with the pivot shaft 4, and the most elevated position of the boom 5 is It becomes higher by the upward movement than when the base 5a is stationary.
The shaft hole 8 of the mast 3 is provided with a receiving means 9 at the lower part 8a, and even if a backward load is applied to the boom 5 when a rescue operation is performed with the working tool 7 in contact with the ground, the pivoting support 9 is provided. The upward movement of the shaft 4 is restricted to support the backward load of the boom 5.

  The receiving means 9 is formed in the lower part 8a of the shaft hole 8 by an arc-shaped slotted hole wall through which the center of curvature R passes behind the tip of the work tool 7, or by an inclined slotted hole wall through which a perpendicular passes. By doing so, the backward load of the boom 5 can be supported with an extremely simple structure, and the vertical movement of the pivot shaft 4 in the shaft hole 8 can be smoothly performed.

  According to the present invention, when the boom is raised from a state where the work tool is grounded, the base portion of the boom is moved upward, and the highest lift position of the boom can be increased by the amount of the upward movement of the base portion.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1-3, 1 is the front loader with which the tractor 11 illustrated as a traveling vehicle was mounted | worn.
The tractor 11 has a front transmission case 12 and a rear transmission case 13 connected to the rear part of the engine E, and a front axle frame 14 projects forward from the engine E to form a traveling vehicle body 2. The engine E and the front axle frame The radiator mounted on the vehicle 14 is covered with a bonnet 15, a control unit 16 is formed at the rear of the bonnet 15, and a working device lifting / lowering hydraulic device 17 and a driver's seat 18 are mounted on the rear upper part of the traveling vehicle body 2.

  The front loader 1 is detachably attached to a left and right mounting frame 20 fixed in the middle of the front and rear of the traveling vehicle body 2, and a pair of left and right masts 3 attached to the mounting frame 20, and the left and right masts 3. A pair of left and right booms 5 connected via a pivot shaft 4, a boom cylinder 6 provided between each mast 3 and a longitudinally intermediate position of the boom 5 to raise and lower the boom 5, and the left and right booms And a work tool cylinder 21 provided between the work tool 7 and the boom 5 for scooping and dumping the work tool 7. ing.

Each of the left and right mounting frames 20 includes a plate-shaped mounting body 20a that is mounted across the front mission case 12 and the front axle frame 14, a support body 20b that protrudes left and right outward from the mounting body 20a, and the support body. The left and right mounting bodies 20a are connected by a connecting rod that passes under the engine E. The support body 20c is erected upward from the outer end of 20b.
The support body 20b and the support body 20c are formed of an angle material having a U-shaped cross section, and the support body 20c is formed in a square tube shape by welding a reinforcing material to the lower half, and the upper half is formed by a mast 3. It can be inserted. An engaging part 22 is provided through the pin in the middle part of the column body 20c, and a pin hole 23 is formed in the upper part.

The mast 3 is formed of a flat plate, and an engagement recess 24 that can be engaged with the engagement portion 22 of the support column 20c is formed at a lower portion thereof, and the engagement recess 24 is engaged with the engagement portion 22 in the middle of the upper and lower sides. In this state, a pin hole 25 facing the pin hole 23 is formed, and the mast 3 is attached to the mounting frame 20 by inserting the pin 26 into both the pin holes 23 and 25.
A piston rod 6a of a boom cylinder 6 is connected to the lower portion of the mast 3, and a shaft hole 8 penetrating the pivot shaft 4 connecting the base portion 5a of the boom 5 is formed in the upper portion.
The shaft hole 8 is a long hole that is long in the vertical direction, and has a substantially square shape in side view. That is, the shaft hole 8 is inclined forward and upward from the lower end to the middle bent portion, and is inclined rearward and upward from the middle bent portion to the upper end. The lower portion 8a from the lower end to the middle bent portion is placed on the pivot shaft 4 A receiving means 9 for restricting movement is provided.

This receiving means 9 is formed of an arc-shaped long hole wall through which the center line of curvature R passes from the rear end of the work tool 7.
The posture of the boom 5 indicated by a two-dot chain line in FIGS. 1 and 2 is a state in which the work tool 7 is substantially grounded. In this state, the work tool 7 scoops up the debris by moving the tractor 11 forward. A backward load is applied to the boom 5, which is supported by the mast 3 via the pivot shaft 4. When the load of the pivot shaft 4 is supported by the shaft hole 8, the long hole wall (receiving means 9) of the lower portion 8 a of the shaft hole 8 has an arc shape with the center of curvature R as the rear side from the tip of the work tool 7. If it exists, the component force which goes to the lower end of the shaft hole 8 acts on the pivot shaft 4, and scooping work with the work tool 7 can be performed while the pivot shaft 4 is held at the lower end of the shaft hole 8.

When the boom cylinder 6 is extended and raised from the posture shown by a two-dot chain line in FIGS. 1 and 2, the boom cylinder 6 is connected to the middle position in the longitudinal direction of the boom 5, and the boom 5 is attached to the tip of the boom 5. Due to the presence of the tool 7, the center of gravity of the boom 5 is positioned in front of the connection point of the boom cylinder 6, and the boom 5 receives the force of lowering the front side around the connection point of the boom cylinder 6 and raising the base portion 5a. Even if the receiving means 9 is present, the base 5 a of the boom 5 is allowed to move upward, and the pivot shaft 4 moves to the upper end of the shaft hole 8.
Therefore, when the work tool 7 scoops up the soil and raises it, the base 5a of the boom 5 moves upward from the lower end to the upper end of the shaft hole 8, so that the work at the tip of the boom 5 is increased by the amount that the base 5a is moved up. The tool 7 also has the highest rising position.

The arc-shaped elongated hole wall of the receiving means 9 of the shaft hole 8 may be short, i.e., formed only on the surface of the lower end of the shaft hole 8 where the pivot shaft 4 receives a rearward load from the boom 5, What is necessary is just to regulate the upward movement of the pivot shaft 4. The vertical length of the shaft hole 8 is, for example, 5 to 20 cm.
The receiving means 9 may be formed of an inclined long hole wall through which a perpendicular line (substantially the same angle as the curvature center line R) passes behind the tip of the work tool 7. If the surface of the lower end of the shaft hole 8 against which the pivot shaft 4 contacts is an inclined wall with a forward tilt posture, the backward force component of the pivot shaft 4 is generated downward, and the pivot shaft 4 is moved into the shaft hole 8. It comes to press against the back of the lower end, and the upward movement is restricted.

FIG. 4 shows a modified example of the present invention. The shaft hole 8 of the mast 3 is formed in a straight line in the vertical direction, and a lock pin 28 serving as a receiving means 9 is shafted by a solenoid 29 at a lower portion 8 a of the shaft hole 8. It is provided on the hole 8 so as to be retractable.
The mast 3 is provided with pin receivers 30 at the front and rear of the shaft hole 8, and then the lock pin 28 is projected from the pin receiver 30R and inserted into the front pin receiver 30F, thereby being positioned at the lower end of the shaft hole 8. The pivot shaft 4 is restricted from moving up.
Although the solenoid 29 is used to move the lock pin 28 in and out, a hydraulic cylinder may be used, and the solenoid 29 may be disposed on the front side of the mast 3.

In this modified example, the work tool 7 allows the upper part of the base 5a of the boom 5 to be moved upward by always retracting the lock pin 28 when the work tool 7 scoops debris or raises it after scooping. When scooping out the debris, the lock pin 28 protrudes to hold the pivot shaft 4 at the lower end of the shaft hole 8, and after scooping, the lock pin 28 is retracted to allow the base 5a of the boom 5 to move upward. Thus, when scooping up the soil or when it is lifted after scooping, the lock pin 28 is always protruded and the pivot shaft 4 is held at the lower end of the shaft hole 8.
In the present invention, the shape of each member and the positional relationship between the front, rear, left, and right in the embodiment are best configured as shown in FIGS. However, it is not limited to the said embodiment, A member, a structure can be variously changed, and a combination can also be changed.

  For example, the mast 3 is erected and fixed to the support body 20b of the mounting frame 20, and the front loader 1 is configured as a front loader exclusive machine that is not attached to or detached from the traveling vehicle body 2, or one post body 20c of the mounting frame 20 is provided. Alternatively, the mast 3 may be formed in a U-shaped cross section that fits to the support column 20c.

1 is an overall side view showing an embodiment of the present invention. It is a side view of the principal part. It is an enlarged side view of a mast. It is a side view of the principal part which shows the modification of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Front loader 2 Traveling vehicle body 3 Mast 4 Pivot shaft 5 Boom 5a Base 6 Boom cylinder 7 Work tool 8 Shaft hole 9 Receiving means

Claims (3)

The base (5a) of the boom (5) is connected to the mast (3) mounted on the traveling vehicle body (2) via the pivot shaft (4), and between the mast (3) and the boom (5). In the front loader provided with a boom cylinder (6) for raising and lowering the boom (5), and provided with a work tool (7) at the tip of the boom (5),
The mast (3) penetrates the pivot (4) to allow the base (5a) of the boom (5) to move upward when the boom (5) is raised from a state where the work tool (7) is grounded. A front loader characterized in that a shaft hole (8) for use is formed vertically long.   The mast (3) moves the pivot shaft (4) upward to support the backward load of the boom (5) with the work tool (7) in contact with the lower part (8a) of the shaft hole (8). The front loader according to claim 1, further comprising a receiving means (9) for regulating.   The receiving means (9) is formed in a lower part (8a) of the shaft hole (8), and an arc-shaped elongated hole wall through which the center line of curvature (R) passes from the rear side of the tip of the work tool (7), Alternatively, the front loader according to claim 2, wherein the front loader is formed by an inclined long hole wall through which a perpendicular passes.

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