JPH09125447A - Fitting structure of attachment of frontloader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the fitting workability of an attachment, by inserting a connection pin into a pin hole in a snap hitch and urging the connection pin by a coil spring and providing an operating lever for the connection pin at the snap hitch, and providing an unlocking metal tool for the operating lever in a four-node link mechanism. SOLUTION: An operating lever 25 for a connection pin is locked in the state that the tip of the connection pin 20 is retracted from the pin hole 13b of a snap hitch 13. The snap hitch 13 is positioned close to a bucket in the state that the snap hitch 13 is turned downward and brought to a stop on the nearly extended line of a lift arm. The snap hitch 13 is turned upward and the hook 13a is fitted to a fixing pin of the fitting bracket of the bucket. When the unlocking metal tool 25 for the operating lever of a four-node link mechanism is moved to get out of the fixing base 21 and release the locked state, the bucket is connected to the snap hitch 13 with the pin by the tensile force of the spring 26 and fitted to the tip of the lift arm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanism for mounting an attachment, such as a bucket or a fork, which is a desired working machine mounted on the tip of a front loader.

[0002]

2. Description of the Related Art Mainly in agricultural work, for loading, unloading and transporting grass, compost, earth and sand, etc., a bucket, which is a desired working machine, is attached to a tip end of a lift arm which is provided on a traveling vehicle such as a tractor so that it can be undulated. Front loaders with attachments such as forks are used.

FIG. 5 shows a front loader of this type. In the figure, (1) is a tractor, (2) is a side frame attached to the front part of the tractor (1),
(3) is a lift arm that is pivotally attached to the side frame (2) via a pivot (4) and is undulated by a lift cylinder (5), and (6) has a pivot (7) at the tip of the lift arm (3). With a snap hitch that is pivotally attached via a 4-bar linkage (8) and lifted up by a dump cylinder (9), an attachment that is a desired working machine, for example, a bucket (10) is detachably pin-coupled. is there. That is, the bucket (10) is attached to the hook portion (6a) of the snap hitch (6).
The fixing pin (10a) of the snap hitch (6) and the bucket (10) pin insertion hole (not shown)
By aligning them and inserting and removing the connecting pin (11), the snap hitch (6) can be inserted into the bucket (1).
0) is detachably attached to the pin.

For example, when loading earth and sand on a truck or the like, first, the lift arm (3) is laid down by the lift cylinder (5) to hold the bucket (10) at the descending end position, and in this state, the tractor. While moving forward (1),
By rotating the bucket (10) upward with the dump cylinder (9), the earth and sand are scooped into the bucket (10), and then the lift arm (3) is erected with the lift cylinder (5) to lift the basket (10). After lifting the tractor (1) to the standby position such as a truck in this state by lifting it to the ascending end position, the dump cylinder (9) rotates the bucket (10) downward to scoop it into the bucket (10). The earth and sand they have dropped are dropped by their own weight and loaded onto trucks, etc.

[0005]

By the way, the above-mentioned front loader is provided with attachments, which are a wide variety of working machines, so as to suit the work contents, and are appropriately replaced for use.

However, in the conventional front loader, an attachment, for example, a bucket (1
When attaching and detaching 0), the connecting pin (11) was directly pulled out from the pin fitting insertion holes of the snap hitch (6) and the bucket (10) by hand, which made the attachment workability poor. Further, since the connecting pin (11) which can be freely inserted and removed is simply inserted into the pin fitting insertion holes of the snap hitch (6) and the bucket (10), the connecting pin () is vibrated when traveling on rough terrain or on a rough road. 11) could be pulled out of the pin fitting holes of the snap hitch (6) and bucket (10).

The present invention has been proposed in view of the above problems, and an object of the present invention is to improve the workability of attachment attachment and to attach the attachment of the front loader to prevent the connecting pin from being pulled out. To provide a mechanism.

[0008]

In order to achieve the above-mentioned object, the present invention mounts a snap hitch, which is lifted by a dump cylinder via a four-bar linkage, on the tip of a lift arm. The fixing pin provided on the attachment is engaged with the hook provided on the upper end, and the pin fitting insertion hole provided on the lower portion of the snap hitch is aligned with the pin fitting insertion hole provided on the attachment to insert the coupling pin. As a result, in the front loader that attaches the attachment to the snap hitch detachably,
A coupling pin is slidably inserted into the pin fitting hole of the snap hitch, and the coupling pin is biased by a coil spring so that the tip projects from the pin fitting hole of the snap hitch. A coupling pin operating lever that retracts the tip of the coupling pin toward the pin fitting hole of the snap hitch is swingably provided so that it can be hooked on a part of the snap hitch, and snaps to the four-bar link mechanism. The feature is that an operating lever release fitting is provided to release the lock of the connecting pin operating lever in relation to the rotation of the hitch.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view of a lift arm tip portion of a front loader according to the present invention, FIG. 2 is a front view of a snap hitch assembly attached to the lift arm tip portion of a front loader according to the present invention, and FIGS. It is a side view which shows the attachment point of an attachment.

1 and 2, (12) is a lift arm, (13) is a snap hitch, (14) is an attachment as a desired working machine, for example, a bucket, (15) is a dump cylinder, and (16) is The four-bar linkage is shown.

The lift arm (12) is provided on both sides of a front part of a tractor (not shown) so that it can be raised and lowered, and a support bracket (17) of a snap hitch (13) is integrally fixed to the tip end thereof.

The snap hitch (13) is a frame-like member having a hook portion (13a) on the outer upper end and a pin fitting hole (13b) on the lower portion, and is a two connecting rod (18) (18). ) Are symmetrically and integrally connected at a predetermined interval. This snap hitch (13) is rotatably pivotally attached to a support bracket (17) of a lift arm (12) via a pivot (19), and a connecting pin (20) is slid into a pin fitting insertion hole (13b). It is inserted freely. A fixed base (21) is integrally fixed to the inner surface of one of the snap hitches (13), and a pivot shaft (22) projecting from the fixed base (21) is provided with an intermediate portion of the rotary link (23). The part is pivotally attached. The rear end of the coupling pin (20) fitted into the pin fitting hole (13b) of one snap hitch (13) is pin-coupled to the tip of the rotary link (23), and The rear end portion of the connecting pin (20) fitted into the pin fitting hole (13b) of the other snap hitch (13) is connected via the connecting pin connecting rod (24), and the connecting pin is operated. A lever (25) is pivotally mounted in the front-back direction (perpendicular to the plane of FIG. 2) so as to be swingable. The other snap hitch (13) and connecting pin connecting rod (2
A coil spring (26) is stretched between the coil spring (26) and the coil spring (26), and the coil spring (26) is always counterclockwise (in FIG. 2) to the rotary link (23) via the connecting pin connecting rod (24). Is applied to the tip end of the coupling pin (20) so as to project from the pin fitting hole (13b) of the snap hitch (13). At a predetermined position of the fixed base (21), an operation lever retaining portion (21a) formed by cutting and bending a part of the fixed base (21) is provided, and the operation lever retaining portion (21a). ), The connecting pin operation lever (25) is locked to lock the connecting pin operation lever (25) with the connecting pin (20) retracted.

The bucket (14) has a mounting bracket (27) integrally fixed to the rear rear surface thereof, a fixing pin (27a) provided at an upper portion of the mounting bracket (27), and a pin fitting insertion hole (27b) at a lower portion thereof. Is provided.

The dump cylinder (15) has a bracket (not shown) whose base end is provided in the middle upper part of the lift arm (12).
The piston rod (15a) is pivotally attached to the four-node link mechanism (16).

The four-bar linkage (16) is composed of a first link (30) and a second link (31) whose one ends are pivotally attached to each other via a pivot (29), and the other end of the first link (30). Is pivotally attached to the snap hitch (13), and the other end of the second link (31) is pivotally attached to the lower part of the tip of the lift arm (12).
9) Piston rod (15a) of dump cylinder (15)
Is pivoted to On the inner surface of the first link (30), there is an operation lever release fitting (32) corresponding to the connecting pin operation lever (25) hooked on the lever hooking portion (21a) of the fixed base (21). It is fixed.

The above is the configuration of the present invention. Next, the attachment mounting procedure of the present invention in the above configuration will be described.

When mounting the attachment, for example, the bucket (14), first, the connecting pin operating lever (25)
The rotating lever (23) is rotated clockwise against the tensile force of the coil spring (26) to move the connecting pin (20) through the rotating link (23) and the connecting pin connecting rod (24). After retreating the tip toward the pin fitting hole (13b) of the snap hitch (13), swing the coupling pin operating lever (25) in the direction a of FIG. 1 to move it to the fixed base (21). The connecting pin operating lever (25) is locked in a state where the connecting pin (20) is retracted by being hooked on the operating lever locking portion (21a). Next, the piston rod (15a) of the dump cylinder (15) is extended and the snap hitch (13) is rotated downward via the four-bar linkage (16) to lift it diagonally downward to the lift arm ( Rest on the extension line of 12) (see Fig. 3). Then, in this state, the tractor is appropriately moved to bring the snap hitch (13) close to the bucket (14) placed on the ground, and then the piston rod (15a) of the dump cylinder (15) is retracted. Rotate the snap hitch (13) upward and, if necessary, slightly lift the lift arm (12) to operate the snap hitch (13) hook portion (13a) to attach the bucket (14) mounting bracket (27). ) Is engaged with the fixing pin (27a) (see FIG. 4). Then, when the piston rod (15a) of the dump cylinder (15) is withdrawn and the snap hitch (13) is turned upward, the pin fitting insertion hole (13b) of the snap hitch (13) is fixed to the fixing pin (27a). Pivot around the pin (27b) of the pin (14) of the mounting bracket (27) of the bucket (14)
, And thus the pin fitting hole (13b) of the snap hitch (13) is attached to the mounting bracket (2) of the bucket (14).
When aligned with the pin insertion hole (27b) of 7), the operation lever release fitting (32) fixed to the inner surface of the first link (30) of the four-bar linkage (16) is connected to the coupling pin operation lever (2).
5) and swings it in the direction b in FIG. 1, whereby the connecting pin operating lever (25) is released from the operating lever latching part (21a) of the fixed base (21) and the locked state is released. It Then, the rotation link (23) is rotated counterclockwise in FIG. 2 by the tensile force of the spring (26), and the rotation of the rotation link (23) causes the tip of the coupling pin (20) to snap hitch. The pin fitting insertion hole (27) of the bucket (14) protruding from the pin fitting insertion hole (13b) of the (13).
The bucket (14) is pin-connected to the snap hitch (13) and is attached to the tip of the lift arm (12). In this state, to remove the bucket (14) from the tip of the lift arm (12), use the connecting pin operation lever (25) to move the rotating lever (23) to the coil spring (2).
When rotated clockwise against the pulling force of 6), the tip of the connecting pin (20) is fitted with the pin of the snap hitch (13) via the rotating link (23) and connecting pin connecting rod (24). Since it retreats toward the insertion hole (13b) and is pulled out from the pin fitting insertion hole (27b) of the mounting bracket (27) of the bucket (14), the pin connection between the snap hitch (13) and the bucket (14) is made. It will be canceled. Then, the piston rod (15a) of the dump cylinder (15) is extended to rotate the snap hitch (13) downward, and if necessary, the lift arm (12) is slightly depressed to operate the snap hitch (13). When the hook portion (13a) of 13) is removed from the fixing pin (27a) of the mounting bracket (27) of the bucket (14), the bucket (14) is removed from the tip of the lift arm (12).

[0018]

As described above, according to the present invention,
When attaching or detaching the attachment, it is not necessary to manually insert the connecting pin into the pin fitting hole of the snap hitch and the attachment, and the operator can operate the lift arm from the driver's seat of the tractor.
The workability of attaching the attachment can be improved. Moreover, since the tip of the connecting pin is biased by the coil spring so as to project from the pin fitting insertion hole of the snap hitch, there is a possibility that the connecting pin may be pulled out by vibration when traveling on rough terrain or on a rough road. There is nothing at all.

[Brief description of the drawings]

FIG. 1 is a side view of a front end portion of a lift arm of a front loader to which the present invention is applied, and a circle indicated by a chain line is a partial plan view of an arrow portion.

FIG. 2 is a front view of a snap hitch assembly mounted on the tip of the lift arm of the front loader according to the present invention.

FIG. 3 is a side view showing how to attach the attachment.

FIG. 4 is a side view showing how to attach the attachment.

FIG. 5 is a side view showing an example of a front loader mounted on the front part of the tractor.

[Explanation of symbols]

 12 Lift arm 13 Snap hitch 13a Hook part 13b Pin insertion hole 14 Bucket (attachment) 15 Dump cylinder 15a Piston rod 16 Four-bar link mechanism 20 Coupling pin 21 Fixed base 21a Operation lever hooking part 22 Axis 23 Pivot link 24 Coupling Pin connecting rod 25 Coupling pin operating lever 26 Coil spring 30 1st link 31 2nd link 32 Operating lever release bracket

Claims (1)

[Claims] 1. A snap hitch, which is lifted by a dump cylinder via a four-bar linkage, is mounted on the tip of a lift arm, and a hook pin provided on the upper end of the snap hitch is engaged with a fixing pin provided on an attachment. At the same time, in a front loader in which the attachment is detachably attached to the snap hitch by aligning the pin insertion hole provided in the lower portion of the snap hitch with the pin insertion hole provided in the attachment and inserting the connecting pin. , The coupling pin is slidably inserted into the pin fitting insertion hole of the snap hitch, and the coupling pin is biased by the coil spring so that the tip projects from the pin fitting insertion hole of the snap hitch. And push the tip of the connecting pin toward the pin fitting hole of the snap hitch to move it back and forth. It is swingably provided so that it can be hooked to a part of the snap hitch, and the operating lever is released to release the hook of the connecting pin operation lever in relation to the rotation movement of the snap hitch in the 4-bar linkage. Attachment mounting mechanism for front loader, which is equipped with metal fittings.