JP4459773B2 - Attachment attachment mechanism for work equipment - Google Patents

Description

 The present invention relates to an attachment mounting mechanism in which attachments such as a plurality of types of buckets and forks having different types of hitch shapes are selectively detachable at the tip of a lift arm of a work machine such as a wheel loader or a front loader.

 Mainly in agricultural work, for loading and unloading of grass, compost, earth and sand, transportation, etc., attachment of buckets, forks, etc., which are desired work machines, to the tip of a lift arm that can be raised and lowered on a traveling vehicle such as a tractor A front loader equipped with is used.

 FIG. 5 shows this type of front loader. In the figure, 1 is a tractor, 2 is a pair of left and right side frames attached to the front portion of the tractor 1, and 3 is a pair of left and right lifts pivotally attached to the side frame 2 via a pivot 4 and lifted by a lift cylinder 5. Arms 6 are a pair of left and right snap hitches that are pivotally attached to the tip of the lift arm 3 via a pivot shaft 7 and are lifted by a dump cylinder 9 via a four-bar linkage mechanism 8.

 As shown in detail in FIGS. 6 to 8, the snap hitch 6 is provided with a hook portion 6 a at the outer upper end and a pin fitting insertion hole 6 b at the lower portion, and is provided with two upper and lower horizontal connecting rods 18. Are integrally connected symmetrically with a predetermined interval. The snap hitch 6 is pivotally attached to the support bracket 17 of the lift arm 12 via a pivot shaft 19, and the retaining pin 11 is slidably inserted into the pin fitting insertion hole 6b.

 As shown in FIGS. 6 to 8, the snap hitch 6 engages the snap hitch 6 from below with an attachment which is a desired working machine, for example, a fixing pin 10 a on the back of the bucket 10. That is, the mounting bracket 27 is integrally fixed to the back surface of the bucket 10, the fixing pin 10 a is provided at the upper portion of the mounting bracket 27, the pin fitting insertion hole 10 b is provided at the lower portion, and the bucket 10 is attached to the hook portion 6 a of the snap hitch 6. In addition, the snap pin 6 is engaged with the snap hitch 6 and the pin insertion holes 6 b and 10 b of the snap hitch 6 and the bucket 10 are aligned with each other, and the removable pin 11 is inserted into the snap hitch 6. Pins are detachably attached.

 Specifically, as shown in FIGS. 7 and 8, the four-bar linkage mechanism 8 includes a first link 30 and a second link 31 that 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 6, the other end of the second link 31 is pivotally attached to the lower end of the lift arm 12, and the pivot 29 is pivotally attached to the piston rod 9 a of the dump cylinder 9.

 Thus, for example, when earth and sand are loaded on a truck or the like, first, the lift arm 3 is laid down with the lift cylinder 5 of FIG. 5 to hold the bucket 10 at the lowered end position, and at the same time the tractor 1 is advanced in this state. Then, the bucket 10 is rotated upward by the dump cylinder 9 so that earth and sand are poured into the bucket 10, and then the lift arm 3 is raised by the lift cylinder 5 to lift the bucket 10 to the rising end position. Is moved to a standby position such as a truck, and then the bucket 10 is rotated downward by the dump cylinder 9 so that the earth and sand poured into the bucket 10 is dropped by its own weight and loaded onto the truck or the like.

 In the above-described front loader, an optimum one of a wide variety of attachments is appropriately replaced and used so as to suit the work contents. By the way, recently, new attachments with better scooping performance than attachments that can engage with conventional snap hitches are becoming popular. This new attachment has a pair of left and right hook plates 49 in the shape of a downward hook, as shown in FIGS. 3 and 4, instead of the conventional fixing pins. In order to engage the lift arm on the work machine side with the hook plate 49, a horizontal engagement bar is used instead of the conventional snap hitch. The engaging bar attached to the tip of the lift arm is brought into contact with the rear surface of the attachment (bucket 10) at the lower position of the hook plate 49 by advancing the working machine itself. The engaging bar can be easily engaged with the hook plate 49 from below by squeezing.

 In the conventional snap hitch, since it is not always easy to adjust the forward position of the work implement, it sometimes takes time to engage the attachment. However, in the case of the new attachment, the engagement bar may be brought into contact with the back of the attachment. Therefore, the advance position of the work implement can be easily adjusted, and the attachment can be quickly engaged.

 In order to engage the lift arm on the work equipment side with two types of attachments, the old attachment that can engage the snap hitch and the new attachment that can engage the engagement bar, it engages with the snap hitch at the tip of the lift arm. Although it is necessary to provide both the joint bars, such an attachment mounting mechanism has not yet been realized.

 The reason is that the snap hitch that engages the fixed pin of the old attachment has a relatively long tip protruding in the shape of a hook to make it easier to accept the fixed pin. When both the snap hitch and the engagement bar are provided at the end of the lift arm because the dump hitch is squeezed upward by the dump cylinder when it comes to engage the snap hitch with the fixed pin. In the side view with respect to the working machine, the tip hook-shaped portion of the snap hitch is relatively positioned on the front side. In other words, the engagement bar is disposed relatively on the rear side, whereas the tip hook-shaped portion of the snap hitch is disposed relatively on the front side. As a result, there is no particular problem when the old attachment is engaged with the snap hitch. However, when the new attachment is engaged with the engagement bar, the engagement bar is moved by the forward movement of the work implement itself or the squeeze operation of the dump cylinder. The tip of the snap hitch interferes with the back of the attachment before it is brought into contact with the back of the attachment, and the engagement bar cannot be moved any further.

 The present invention has been proposed in view of the above problems, and an object thereof is to provide a novel attachment mounting mechanism that can be engaged in common with two types of old and new attachments.

In order to solve the above-described problems, an attachment mounting mechanism according to the present invention is attached to the tip of a pair of left and right lift arms so as to be rotatable, and a pair of left and right joining plates that are lifted by a dump cylinder, A pair of left and right support plates that are integrally attached at the inner position of the lever, an engagement bar that connects the upper ends of the support plates to each other, and a left and right that are detachably attached to the joint plate at the outer position. A pair of snap hitches, wherein the snap hitch has a tip engagement portion positionally aligned with the engagement bar in a side view of the work implement, and left and right from the pair of left and right support plates said mounting Burake fitted into the pin insertion hole of the mounting bracket provided on the back of the attachment of the working machine a retractable in a direction Characterized by comprising a fixing pin serving as a retaining bets.

  According to the present invention, the snap hitch corresponding to the old attachment and the engagement bar corresponding to the new attachment are provided with the positions of the engaging portions being aligned in position, and the snap hitch is detachable. The old attachment can be mounted in the same way as before, and the new attachment can be removed by removing the snap hitch so that the snap hitch can be prevented from interfering with the attachment. It can be engaged with the plate, and the position of the engaging part of the snap hitch and the engaging bar is aligned with each other in the new and old attachments. Therefore, when the attachment body shape is the same, the load balance on the work machine is different between the old and new attachments. There is nothing and scooping up the attachment Since the one performance was also common, it enables stable work, further various specifications such rake angle and dump angle old attachment may be in common with the prior art. Further, the engagement bar corresponding to the new attachment also serves as a strength member for connecting the left and right support plates, and an attachment mounting mechanism can be constructed with an advantage in cost.

 Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, the attachment mounting mechanism of the present invention has a pair of left and right joining plates 32 and a pair of left and right support plates 33 that are integrally attached to the joining plate 32 at an inner position. The joining plate 32 and the support plate 33 are connected at their lower ends to a common long lower connecting rod 34. The upper ends of the joining plate 32 and the support plate 33 are connected by a pair of left and right upper connecting rods 35. The upper ends of the left and right support plates 33 are connected to each other by a horizontally long engaging bar 36.

 A double rod type hydraulic cylinder 37 is disposed on the lower connecting rod 34 along the longitudinal direction thereof. The hydraulic cylinder 37 has retaining pins 20 that can be projected and retracted by piston rods at both right and left ends. When the hydraulic cylinder 37 is extended, the retaining pin 20 protrudes and is inserted and fitted into the pin fitting hole 45 formed at the lower end portions of the joining plate 32 and the support plate 33.

 As shown in FIG. 2, the shaft hole 40 formed in the lower end portion of the joining plate 32 is pivotally supported by the tip end portion of the lift arm 12. Further, another shaft hole 41 formed in the intermediate portion of the joining plate 32 is pivotally supported at the tip of the first link 30 so as to be freely rotatable. Accordingly, a link mechanism similar to the four-bar linkage mechanism 8 shown in FIGS. 7 and 8 is configured, and the joining plate 32 swings up and down in the front-rear direction by driving the dump cylinder 9.

 A pair of left and right snap hitches 6 are detachably attached to the joining plate 32 by a plurality of bolts or the like at the outer position thereof. A hook-like hook portion 6 a facing toward the front side when viewed from the work machine side is formed at the tip or upper end portion of the snap hitch 6. The hook portion 6a is aligned and aligned with the engagement bar 36 in a side view of the working machine.

 As shown in FIG. 2, a pair of left and right mounting brackets 43 are fixed to the back surface of the old bucket 42 as a kind of attachment. The mounting bracket 43 is formed by fixing a pair of left and right plate members 43a in parallel to each other on the back surface of the bucket 42 with a predetermined interval therebetween, and an engagement pin 44 is fixedly passed between upper end portions of the plate member 43a. A pin fitting hole 45 into which the retaining pin 20 can be inserted and fitted is formed at the lower end of the plate member 43a. Only the pin insertion hole 45 of the inner plate member 43a is useful, and the pin insertion hole 45 of the outer plate member 43a is unnecessary. This is a result of molding the plate material 43a by using a common brace mold.

 As shown in FIGS. 3 and 4, a pair of left and right hook plates 49 are attached to the back surface of the new bucket 48 as a kind of attachment. This hook plate 49 is provided in common with the new attachment, and has a hook portion 49a having a downward hook shape. The width between the hook plates 49 is preferably slightly narrower than the distance between the pair of left and right lift arms 12. As a result, when the attachment to the work machine is mounted, the visibility of the pair of left and right hook plates 49 from the driver's seat of the work machine is not blocked by the lift arm 12, and visibility is improved. A pair of left and right metal fittings with holes into which the retaining pins 20 can be inserted and fitted are fixed to the rear surface of the bucket 48 and below the hook plate 49.

 The four-bar linkage mechanism 8 includes a first link 30 and a second link 31 that are pivotally attached to each other via a pivot 29. The other end of the first link 30 is pivotally attached to the snap hitch 6, and the second link. The other end of 31 is pivotally attached to the lower end of the tip of the lift arm 12, and the pivot 29 is pivotally attached to the piston rod 9 a of the dump cylinder 9.

 The attachment mounting mechanism according to the present invention engages the snap hitch 6 with the engagement pin 44 of the bucket 48 with the snap hitch 6 attached when the old bucket 42 of FIG. 2 is mounted. However, when mounting the new bucket 48 of FIG. 4, the snap hitch 6 is removed, and the engagement bar 36 is engaged with the hook portion 49 a of the hook plate 49 of the bucket 48. When the engagement bar 36 is to be engaged with the hook portion 49a of the hook plate 49 with the snap hitch 6 attached, the work implement itself is advanced as shown in FIG. This is because the snap hitch 6 interferes with the back surface of the bucket 48 and the engagement bar 36 cannot be smoothly engaged with the hook portion 49a of the hook plate 49 when the operation is performed.

 Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made. For example, in the above-described embodiment, a bucket is exemplified as an attachment. However, the present invention is not limited to a bucket and can be similarly applied to other attachments such as a fork.

The front side perspective view of the attachment mounting mechanism which concerns on this invention. The perspective view of the state which mounted | wore the old type bucket back surface with the attachment mounting mechanism which concerns on this invention. The perspective view of the state which mounted | wore the new bucket back surface with the attachment mounting mechanism which concerns on this invention with a snap hitch. The perspective view of the state which removed the snap hitch and attached the attachment mounting mechanism which concerns on this invention to a new type | mold bucket back surface. The side view of the tractor equipped with the front loader in the vehicle front part. The front view of the conventional attachment mounting mechanism. The side view of the conventional attachment mounting mechanism. The side view at the time of bucket mounting of the conventional attachment mounting mechanism.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tractor 2 Side frame 3 Lift arm 4 Pivot 5 Lift cylinder 6 Snap hitch 6a Hook part 6b Pin fitting insertion hole 7 Pivot 8 Four-bar link mechanism 9 Dump cylinder 9a Piston rod 10 Bucket 10a Fixed pin 10b Pin fitting insertion hole 11 Stopping Pin 12 Lift arm 17 Support bracket 18 Connecting rod 19 Pivot 20 Locking pin 27 Mounting bracket 29 Pivot 30 First link 31 Second link 32 Joining plate 33 Support plate 34 Lower connecting rod 35 Upper connecting rod 36 Engaging bar 37 Hydraulic cylinder 40 Shaft hole 41 Shaft hole 42 Old bucket 43 Mounting bracket 43a Plate material 44 Engagement pin 45 Pin insertion hole 48 New bucket 49 Hook plate 49a Hook part

Claims (1)

A pair of left and right joining plates that are pivotally attached to the ends of a pair of left and right lift arms and are raised and lowered by a dump cylinder;
A pair of left and right support plates integrally attached to the joining plate at an inner position thereof;
An engagement bar connecting the upper ends of the support plates;
A pair of left and right snap hitches that are detachably attached to the joining plate at positions outside the joining plate, and the positions of the front end engaging portions of the snap hitches are aligned with each other in a side view of the engagement bar and the work implement The snap hitch being matched ,
A retaining pin that can protrude and retract from the pair of left and right support plates in the left-right direction and is inserted and fitted into a pin fitting insertion hole of a mounting bracket provided on the back surface of the attachment of the work implement ,
An attachment mounting mechanism for a working machine, comprising:

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