JPH0317967B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a bucket holding device that is installed on a work vehicle such as a loader to carry out loading work, etc.

[Prior art and its problems]

In a conventional bucket loader, the bucket is directly held at the tip of a lift arm that is driven up and down by a lift cylinder whose base end is pivotally supported on the vehicle body. For this reason, even if it is desired to vary the reach of the lift arm depending on, for example, the situation at the loading work site or the size of the dump truck, it is not possible to do so. Therefore, at work sites that require a larger dumping reach or clearance for buckets, a longer one-piece lift arm is used to meet these demands. However, a loader equipped with such a lift arm has a problem in that the overall length during traveling becomes long and the turning radius becomes large, making it difficult to turn around easily. On the other hand, as another conventional technology, there is a system in which the lift arm is newly equipped with a hydraulic cylinder dedicated to bucket reach that operates along the longitudinal direction, and the damping reach and damping clearance of the bucket can be varied by this cylinder. . However, in the case of this technology, the hydraulic cylinder must be operated each time the reach or clearance is varied, and the addition of new operating systems requires extensive equipment and maintenance. This also causes inconveniences in terms of cost and cost.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and its main purpose is to provide a bucket holding device that can vary the damping reach and damping clearance of a bucket just by the normal lifting and lowering movement of a lift arm. Another object of the present invention is to provide a bucket holding device that prevents the cargo inside the bucket from spilling out during the swinging of the bucket. Another object of the present invention is to provide a bucket holding device that does not interfere with the turning radius of the vehicle.

[Structure of the invention]

In order to achieve the above object, the present invention includes a lift arm whose base end is rotatably supported on the side of a vehicle body such as a loader, a lift cylinder for driving the arm up and down, and a lift arm mounted on the distal end side of the lift arm in a longitudinal direction. a slider that is slidably attached and extends in the extension direction of the arm; a bucket that is attached to the tip of the slider; and a lift arm that connects the bucket, the slider, and the lift arm to each other and is connected to the vehicle body side. The present invention is characterized by a structure including a link mechanism that causes the slider to slide in the reach extension direction of the lift arm when the link motion is raised, and slides the slider in the opposite direction when the link motion is lowered by the lift arm.

【Example】

Hereinafter, a preferred embodiment of the present invention will be described based on the drawings. In the bucket loader shown in Fig. 1, the vehicle body 1
The base end of the lift arm 2 is rotatably supported on the tower frame. The lift arm 2 is driven up and down by a lift cylinder 3 mounted between the lift arm 2 and the vehicle body 1. A slider 4 is attached to the tip end of the lift arm 2 and extends in the longitudinal direction of the arm. As shown in more detail in FIG. 2, the illustrated slider 4 is a hollow body with a box-like closed cross section, and is slidably fitted to the outside of the lift arm 2. A bucket 5 is pivotally supported at the tip of the slider 4 so as to be rotatable up and down. The tower frame, lift arm 2, slider 4, and bucket 5 of the vehicle body 1 are connected to each other by a link mechanism 6 and a tilt cylinder 7, and their specific related structures will be described below. That is, the link mechanism 6 in the illustrated example includes a first link 6-1 whose base end is connected to the tower frame of the vehicle main body 1 with a pin P2 at a distance above the base end shaft fulcrum P1 of the lift arm 2, and a lift arm 2. An upwardly directed second link 6-2 whose base end is connected with a pin P3 in the middle, and these first and second links 6-
One end is connected to the mutual tip ends of slider 4 with the same pin P4, and the other end is connected to the distal end of the slider 4 with pin P5.
The third link 6-3 is connected to the lift arm 2 between the pins P3 and P5, and its base end is connected to the pin P6.
The fourth link 6-4 and the third link 6- are connected by
The fifth link 6-5 has an intermediate portion connected to a connecting pin P5 on the slider 4 side of No. 3, and a downward end connected to the free end of the fourth link 6-4 by a pin 7. A tilt cylinder 7 is connected between the upward end of the fifth link 6-5 and the upper rear bracket of the bucket 5 by pins P8 and P9. Next, the operation of the above embodiment will be explained. Bucket 5 is in the lift-down position (solid line position in Figure 1)
, the slider 4 is held in the retracted position. When the lift arm 2 is swung up by the lift cylinder 3 from this state, the link mechanism 6 responds accordingly. In this case, since the connection point P2 of the first link 6-1 on the vehicle main body 1 side is located above the base end shaft fulcrum P1 of the lift arm 2 as described above, the swinging up of the lift arm 2 causes the second link 6- 2 rotates counterclockwise in FIG. 1 about the connection point P-3 on the lift arm 2 side. The rotation causes the slider 4 to slide forward via the third link 6-3. At this time, the stroke of the slider 4 gradually increases in proportion to the swing-up height of the lift arm 2. Such forward sliding of the slider 4 extends the reach of the lift arm 2, and the reach becomes the longest at the maximum height when the bucket 5 is swung up. Also, when the lift arm 2 is raised, the fourth
The fifth links 6-4 and 6-5 follow the slider 4 and respond accordingly, so that the bucket cart 5 is swung up to the height for loading onto a dump truck or the like, while always being held at a proper position. Consequently, the cargo in the bucket 5 will not spill out during the swing-up, and therefore there is no need to operate the tilt cylinder 7 during the swing-up. The bucket cart 5 thus swung up to the required height is damped by the tilt cylinder 7, whereby the cargo inside the bucket cart 5 is loaded onto a dump truck or the like. When the bucket cart 5 is swung down after loading, the link mechanism 6 moves in the opposite direction to that when swung up. Therefore, the slider 4 moves back and the lift arm 2
's reach returns to normal.

【Effect of the invention】

As described above, according to the configuration of the present invention, the reach of the lift arm can be automatically varied by moving the slider back and forth with the motion of the link mechanism as the lift arm moves up and down. Therefore, the reach of the lift arm can be extended only by the link motion when the lift arm is raised, and the damping reach and damping clearance of the bucket can be increased. Therefore, the loading work using the bucket can be carried out smoothly and efficiently at all times. Further, since the reach of the lift arm is returned to its original state by lowering the arm, there is no fear that the overall length of the vehicle will become longer and the turning radius will become larger when the vehicle is running.

[Brief explanation of the drawing]

The drawings show a preferred embodiment of the present invention, and FIG. 1 is a side view of a bucket loader, and FIG. 2 is a sectional view taken along the line -- in FIG. 1... Vehicle body, 2... Lift arm, 3...
Lift cylinder, 4...Slider, 5...Bucket, 6...Link mechanism.

Claims (1)

[Scope of Claims] 1. A holding device for a bucket installed on a work vehicle such as a loader, which includes a lift arm whose base end is rotatably supported on the vehicle body side, and a lift cylinder that drives the arm up and down. a slider that is attached to the tip of the lift arm so as to be slidable in the longitudinal direction and extends in the extension direction of the arm; a bucket that is attached to the tip of the slider; and a bucket that interconnects the bucket, the slider, and the lift arm. and a link mechanism that is connected to the vehicle body side and slides the slider in the reach extension direction of the lift arm with a link motion when the lift arm goes up, and slides the slider in the opposite direction with a link motion when the lift arm goes down. A bucket holding device characterized by a configuration comprising: 2. A bucket tote holding device according to claim 1, wherein the slider is a hollow body with a box-like closed cross section and is fitted onto the lift arm so as to be slidable. 3. The bucket cart holding device according to claim 1, wherein the link mechanism includes a tilt cylinder of the bucket cart. 4. In the bucket holding device according to claim 1 or 3, the link mechanism includes a first link whose base end is connected to the vehicle body side apart from the base end shaft fulcrum of the lift arm; A second link connects the tip of the first link and the middle part of the lift arm and extends upward; and a third link connects the mutual tips of the first and second links and the slider. , a fourth link having one end connected to the lift arm at a distance forward from the connection point of the second link; a downward end connected to the other end of the fourth link; and an intermediate portion connected to the slider; a fifth link that maintains the fourth link in parallel with the third link, and a tilt cylinder is installed between the upward end of the fifth link and the bucket. holding device.