JPH07324349A - Bottom dump type loader bucket - Google Patents

Abstract

PURPOSE:To surely prevent a connecting pin from being separated from one-side ends of the oscillating arm of a front bucket and a bucket opening and closing cylinder. CONSTITUTION:A connecting pin 52 for rotatably connecting an oscillating arm 31 to a rod-side boss part 19 is formed, according to the distance dimension L between outside bracket 22A and inside bracket 22B for supporting a hinge pin 23, to have a length slightly shorter than this dimension L. A stopper 53 is provided on a mounting cover 39 for covering a working opening part 38 provided on the outside bracket 22A. When the connecting pin 52 starts to axially displace, thus, since one end side of the connecting pin 52 makes contact with the outside bracket 22A or stopper 53 to regulate the further displacement, and the other end side makes contact with the inside bracket 22B to regulate the further displacement, the connecting pin 52 can be surely prevented from being separated from the oscillating arm 31 and the rod-side boss part 19.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bottom dump type loader bucket which is provided in a construction machine such as a large hydraulic excavator and is preferably used for excavation work or transportation work of earth and sand.

[0002]

2. Description of the Related Art A large hydraulic excavator used for civil engineering work, such as excavating earth and sand, carrying work, etc., usually has a bottom consisting of a rear bucket and a front bucket which can be opened and closed with respect to the rear bucket. It is equipped with a dumper loader bucket.

Therefore, FIGS. 4 to 9 show a bottom dump type loader bucket of a hydraulic excavator.

In the drawings, 1 is a support bracket integrally formed with an upper revolving structure (not shown) of a hydraulic excavator, and 2 is a front as a working device which is provided on the support bracket 1 so as to be able to move up and down. 3 constitutes the front 2,
A boom whose base side is pin-connected to the support bracket 1,
A connecting bracket 4 is fixed to the tip end side of the boom 3. Then, the connection bracket 4 and the support bracket 1
A boom cylinder 5 for driving the boom 3 is arranged between the and.

Reference numeral 6 denotes an arm whose base end side is pin-connected to the connecting bracket 4, and the tip end side of the arm 6 is pin-connected to a mounting bracket 11 of a loader bucket 10 described later. An arm cylinder 7 that drives the arm 6 and a level cylinder 8 are provided between the boom 3 and the arm 6. A bucket swing cylinder 9 that swings the loader bucket 10 is provided between the connecting bracket 4 and the mounting bracket 11.

Reference numeral 10 denotes a bottom dump type loader bucket which is pin-connected to the tip end side of the arm 6 via a mounting bracket 11, and the loader bucket 10 has a rear portion in which the mounting bracket 11 is integrated as shown in FIG. Bucket 1
2 and a bucket connecting portion 21 to be described later on the rear bucket 12.
And a front bucket 13 that is openably and closably connected via the.

Cylinder accommodating portions (not shown) for accommodating bucket opening / closing cylinders 18 to be described later are provided on both left and right sides of the rear bucket 12. Further, the front bucket 13 is formed in a substantially U-shape from a bottom plate 14 and side plates 15 and 15 provided upright on both left and right sides of the bottom plate 14.

Reference numeral 16 is a spill guard formed of a substantially trapezoidal plate-like member that is projected from the upper end of the rear bucket 12, and the spill guard 16 causes the earth and sand scooped by the loader bucket 10 to fall to the rear side of the rear bucket 12. It is designed to prevent you from doing so. Reference numeral 17 denotes a plurality of claws provided on the front edge of the bottom plate 14 constituting the front bucket 13, and the claws 17 excavate the ground or the like.

Reference numeral 18 denotes a pair of bucket opening / closing cylinders (only one is shown) which are arranged on both the left and right sides of the rear bucket 12 to open / close the front bucket 13. The bucket opening / closing cylinders 18 are scooped up by the loader bucket 10. It is arranged in a cylinder accommodating portion (not shown) provided in the rear bucket 12 to protect it from dirt and the like.
A rod-side boss portion 19 provided on one end side (rod side) of the bucket opening / closing cylinder 18 is connected to a swing arm 31 of the front bucket 13 to be described later via a bucket coupling portion 21, and the other end side (tube side). The tube-side boss portion 20 provided in () is pin-connected to the rear bucket 12.

Reference numerals 21 and 21 denote bucket connecting portions which are arranged on both left and right sides of the loader bucket 10 and which openably and closably connect the front bucket 13 to the rear bucket 12. The bucket connecting portion 21 is a rear bucket. 12 left,
A pair of brackets 22 and 22 provided on both right sides and composed of an outer bracket 22A and an inner bracket 22B,
It includes a hinge pin 23, a connecting boss portion 27, a swing arm 31, a connecting pin 32, and the like, which will be described later.

Reference numeral 23 denotes a hinge pin rotatably supported by the outer bracket 22A and the inner bracket 22B via bushes 24, 24. The hinge pin 23 has a disk shape with bolts 25, 25 at one end thereof. Retaining plate 26
Is fixed, and a large-diameter retaining portion 23A is formed on the other end side so that the retaining portion is retained. Also, a grease hole 23B is provided in the center of one end side of the hinge pin 23, and a grease passage (not shown) is formed in the hinge pin 23 for guiding the grease injected through the grease hole 23B to the outer peripheral side of the hinge pin 23. Has been done.

27 is integrally formed with the side plate 15 of the front bucket 13, and the rear bucket 1 is provided with the hinge pin 23.
2 shows a connecting boss portion rotatably connected to the second bracket 22. The connecting boss portion 27 is formed with a pin insertion hole 27A, and the pin insertion hole 27 has a bearing bush 28,
The hinge pin 23 is rotatably inserted through 28. Reference numeral 29 denotes an annular reinforcing plate provided on the inner bracket 22B so as to be in sliding contact with the connecting boss portion 27.
An abutting portion between the connection member 9 and the connecting boss portion 27 is covered with an O-ring 30 over the entire circumference to prevent intrusion of earth and sand or the like.

Reference numeral 31 denotes a bifurcated swing arm that is integrally formed with the connecting boss portion 27 and is located at the tip end side of the side plate 15. The tip end side of the swing arm 31 has a pair of pin insertion holes 3
1A and 31A are formed. Then, the swing arm 3
1, the rod side boss portion 1 of the bucket opening / closing cylinder 18
9, the rod side boss portion 19 and the swing arm 31 are inserted.
And are rotatably connected via a connecting pin 32 described later.

Reference numeral 32 denotes each pin insertion hole 31 of the swing arm 31.
A and the rod side boss portion 19 of the bucket opening / closing cylinder 18
With the connecting pin inserted into the pin hole 19A formed in
Bushings 33, 33 are fitted between the connecting pin 32 and each pin insertion hole 31A, and the connecting pin 32 and the pin hole 20A are inserted.
A bearing bush 34 is inserted between and.

Reference numeral 35 denotes a grease nipple provided on one end side of the connecting pin 32. The grease injected through the grease nipple 35 is introduced into the connecting pin 32.
A grease passage (not shown) that leads to the sliding surface between the bearing bush 34 and the bearing bush 34 is formed. Further, a fitting groove 32A having a "U" -shaped cross-sectional shape into which a retaining plate 36 described later is fitted is formed on the outer peripheral portion on one end side of the connecting pin 32.

Reference numeral 36 denotes a retaining plate fitted in the fitting groove 32A of the connecting pin 32. The retaining plate 36 is fixed to the swing arm 31 via a bolt 37 while being fitted in the fitting groove 32A. By doing so, the connecting pin 32 is prevented from being pulled out and prevented from rotating.

Reference numeral 38 denotes a work opening formed in the outer bracket 22A. The work opening 38 allows the connecting pin 32 to be detached and attached from the outside of the outer bracket 22A during maintenance. There is.

Reference numeral 39 denotes a mounting cover which covers one end side of the hinge pin 23 protruding outward of the outer bracket 22A together with the working opening 38, and the mounting cover 39 is a substantially U-shaped frame fixed to the outer bracket 22A. It is detachably attached to the body 40 via a plurality of bolts 41, 41, .... Then, the frame 40 projects from the outer bracket 22A with a certain size, and each bolt 25 on the hinge pin 23 side
A gap is formed between the mounting cover 39 and the mounting cover 39. Also,
The mounting cover 39 has a grease hole 23B for the hinge pin 23.
And an injection hole 39B is formed in a portion of the connecting pin 32 opposed to the grease nipple 35, and the hinge pin 23 is connected to the hinge pin 23 through the respective injection holes 39A and 39B. The pin 32 is filled with grease.

In the bottom dump type loader bucket 10 constructed as described above, the swing arm 31 swings about the hinge pin 23 as a fulcrum (center) when the bucket opening / closing cylinder 18 expands / contracts, and the swing arm 31 swings. With side plate 1
The front bucket 13 is moved to the position shown in FIG.
As shown in FIG. 3, the rear bucket 12 is closed, and in this state, excavation work such as earth and sand and transportation of scooped earth and sand are performed, and when the bucket opening / closing cylinder 18 is contracted, the front bucket 13 opens to the rear bucket 12. By doing so, it is designed to discharge the transported earth and sand.

[0020]

By the way, in the above-mentioned prior art, when the front bucket 13 is opened and closed, the swing arm 31 is moved around the hinge pin 23 so that the rod side boss portion 19 of the bucket opening and closing cylinder 18 and the connecting pin 3 are provided.
Since it is configured to swing together with 2 or the like, it is necessary to smoothly slide (rotate) the connecting pin 32 in the bearing bush 34 inserted into the pin hole 19A of the rod side boss portion 19.
Therefore, grease is supplied to the sliding surface between the connecting pin 32 and the bearing bush 34 to ensure lubricity.

However, in the prior art, when sufficient grease is not supplied due to, for example, a defect during maintenance, the lubricity of the sliding surface between the connecting pin 32 and the bearing bush 34 deteriorates, and smooth sliding is achieved. When the mobility is not obtained, the connecting pin 32 receives a large turning torque when the bucket opening / closing cylinder 18 expands / contracts, and this excessive torque acts as a shearing force on the bolt 37 fixing the retaining plate 36. As a result, the bolt 37 may be broken.

Since the connecting pin 32 is covered by the mounting cover 39, if the worker continues the work without noticing the breakage of the bolt 37, the retaining plate 36 is removed.
May be disengaged from the fitting groove 32A of the connecting pin 32, and the connecting pin 32 may separate from the swing arm 31 as shown in FIG. In this way, when the bucket opening / closing cylinder 18 expands and contracts with the connecting pin 32 separated from the swing arm 31, the rod side boss portion 19, the connecting pin 32,
Many parts such as the swing arm 31, the outer bracket 22A, the inner bracket 22B, and the like are damaged, and it takes a lot of time and cost to repair and replace these damaged parts, and also to ensure safety. There is a problem that it becomes difficult.

The present invention has been made in view of the above-mentioned problems of the prior art, and it is possible to reliably prevent the connecting pin from coming off from the swing arm of the front bucket and the one end side of the bucket opening / closing cylinder, thereby ensuring safety. Another object of the present invention is to provide a bottom dump type loader bucket capable of stabilizing the opening / closing operation of the front bucket.

[0024]

In order to solve the above-mentioned problems, the present invention relates to a bucket opening / closing cylinder in which a rear bucket and a front bucket are rotatably connected by a hinge pin, and a swing arm provided on the front bucket. It is applied to a bottom dump type loader bucket that opens and closes the front bucket from the rear bucket when the bucket opening and closing cylinder extends and contracts by rotatably connecting to one end side of the bucket through a connecting pin.

In the invention according to claim 1, an inner bracket and an outer bracket for supporting both end sides of the hinge pin are provided on both left and right sides of the rear bucket, and the connecting pin is provided on the outer bracket. It is characterized in that a stopper is provided for restricting the opening and closing cylinder from being detached from one end side and the swing arm of the front bucket.

Further, as in the invention described in claim 2, a working opening for detaching the connecting pin from the one end side of the bucket opening / closing cylinder and the swing arm of the front bucket is formed in the outer bracket. And a mounting cover that removably covers the opening, and the stopper is preferably mounted on the outer bracket via the mounting cover.

Further, as in the invention described in claim 3,
It is preferable that the connecting pin is formed with a length corresponding to a distance between the outer bracket and the inner bracket.

Further, as in the invention described in claim 4, the inner bracket may be provided with another stopper for restricting axial displacement of the connecting pin with the stopper.

[0029]

According to the first aspect of the present invention, the connecting pin receives excessive torque when the bucket opening / closing cylinder expands / contracts due to running out of grease, etc., and the connecting pin is likely to come off from the swing arm of the front bucket and one end of the bucket opening / closing cylinder. Even in this case, the movement (disengagement) of the connecting pin can be restricted by the stopper provided on the outer bracket, and the opening / closing operation of the front bucket can be continued according to the expansion / contraction of the bucket opening / closing cylinder.

According to the second aspect of the present invention, by removing the mounting cover from the outer bracket, the connecting pin can be detached from the swing arm of the front bucket, and maintenance and inspection work can be easily performed. Then, in the state where the working opening of the outer bracket is covered by mounting the mounting cover, the stopper provided on the outer bracket via the mounting cover can reliably restrict the disengagement of the connecting pin.

Further, according to the invention of claim 3, the length of the connecting pin is set to a length corresponding to the distance between the inner bracket and the outer bracket, so that the stopper on the outer bracket side and the inner bracket are The axial displacement of the connecting pin can be regulated between them, and the connecting pin can be reliably prevented from coming off from the swing arm or the like.

Furthermore, according to the invention of claim 4, by providing another stopper on the inner bracket, the axial displacement of the connecting pin can be regulated between the other stopper and the stopper provided on the outer bracket. It is possible to reliably prevent the connecting pin from coming off from the swing arm or the like.

[0033]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In the embodiment, the same components as those of the prior art shown in FIGS. 4 to 9 are given the same reference numerals and the description thereof will be omitted.

In the figure, reference numeral 51 denotes a bucket connecting portion applied to the bottom dump type loader bracket according to the present embodiment. The bucket connecting portion 51 is substantially the same as the bucket connecting portion 21 described in the prior art, and the outer bracket 22A. ,
Although it includes the inner bracket 22B, the hinge pin 23, the connecting boss portion 27, the swing arm 31, the connecting pin 52, etc., the bucket connecting portion 51 is different from the prior art in that the stopper pin 53 prevents the connecting pin 52 from coming off. Are different.

Reference numeral 52 denotes a swing arm 31 of the front bucket 13 and a rod side boss portion 19 of the bucket opening / closing cylinder 18.
The connecting pin in which the and are rotatably connected is shown.
The axial length of 2 corresponds to the distance L between the outer bracket 22A and the inner bracket 22B that support the swing arm 31 via the hinge pin 23, and is slightly shorter than the distance L. . Further, a fitting groove 52A having a "U" -shaped cross-sectional shape into which the retaining plate 36 fits is formed on the outer peripheral portion on one end side of the connecting pin 52.

Reference numeral 53 is a stopper for restricting the connection pin 52 from coming off from the swing arm 31 and the rod side boss portion 19 of the bucket opening / closing cylinder 18, and the stopper 53 is formed on the outer bracket 22A as shown in FIG. It is formed in a plate shape with a width dimension slightly smaller than the width of the opened work opening 38. Here, the stopper 53 is fixed to the mounting cover 39 at the base end side, and the end surface on the tip end side facing the working opening 38 is located on the same plane as the inner surface of the outer bracket 22A. The stopper 53 is shown in FIG.
As shown in FIG.
Even when 1 swings about the hinge pin 23, the end face of the connecting pin 52 on one end side is always opposed.

As described above, the connecting pin 52 swinging together with the swing arm 31 about the hinge pin 23 when the front bucket 13 is opened and closed has one end on the outer bracket 22A or the stopper 53 and the other end on the inner bracket 22B. , Are arranged to face each other with a slight gap.

The bottom dump type loader bucket according to the present embodiment is provided with the bucket connecting portion 51 constructed as described above, and the basic operation thereof is not different from that of the prior art.

However, in this embodiment, the outer bracket 2
The connecting pin 52 is formed with a length corresponding to the distance L between the inner bracket 22B and the inner bracket 22B, and the plate-like stopper 53 is provided on the mounting cover 39. Even if the lubricity of the sliding surface with the bush 34 is deteriorated and the bolt 37 is damaged and the retaining plate 36 comes off from the fitting groove 52A, the connecting pin 52 is reliably retained. Can be held at

That is, when the connecting pin 52 starts to be displaced axially from the swing arm 31 or the like due to the expansion and contraction of the bucket opening / closing cylinder 18, one end of the connecting pin 52 contacts the outer bracket 22A or the stopper 53 and is further moved. Of the inner bracket 22B on the other end side is restricted.
It is possible to reliably prevent the connecting pin 52 from being disengaged from the swing arm 31 and the rod side boss portion 19 of the bucket opening / closing cylinder 18 because it is abutted against the shaft and further axial displacement is restricted.

Therefore, for example, the retaining plate 36 is fitted into the fitting groove 52.
Even if the bucket opening / closing cylinder 18 expands / contracts while being separated from A, the rod side boss portion 19, the connecting pin 32, the swing arm 3
1, further outer bracket 22A, inner bracket 2
It is possible to prevent the 2B and the like from being damaged, and it is possible to greatly reduce the time and cost spent for repairing and replacing the damaged parts, and also to improve the safety during work.

FIG. 3 shows a second embodiment of the bottom dump type loader bucket according to the present invention. In the second embodiment, the same components as those of the first embodiment shown in FIGS. Are denoted by the same reference numerals, and description thereof will be omitted.

In the figure, 61 is the inner bracket 22B.
And another stopper (hereinafter, referred to as a second stopper) that is provided in the
The second stopper 61 is formed as an arc-shaped plate corresponding to the trajectory of the connecting pin 63 centered on the hinge pin 23, and is fixed to the inner surface of the inner bracket 22B via the bolt 62. Has been done.

63 is a connecting pin, and the connecting pin 63 is the second
Corresponding to the distance L'between the inner surface of the stopper 61 and the outer bracket 22A, it is formed with a dimension slightly shorter than this distance L '. A fitting groove 63A into which the 36 fits is formed. One end of the connecting pin 63 faces the outer bracket 22A or the stopper 53, and the other end faces the second stopper 61 with a slight gap therebetween.

In the second embodiment constructed as described above, when the connecting pin 63 starts to be displaced in the axial direction from the swing arm 31 or the like due to the expansion and contraction of the bucket opening / closing cylinder 18, one end side of the connecting pin 63 is Outer bracket 22A
Alternatively, the contact pin 53 contacts the stopper 53 to restrict further axial displacement, and the other end contacts the second stopper 61 to restrict further axial displacement. It is possible to reliably prevent the bucket opening / closing cylinder 18 from coming off from the rod side boss portion 19.

In the first embodiment, an example in which the stopper 53 fixed to the mounting cover 39 is formed as a linear plate-like member has been described, but the present invention is not limited to this, and the center of the hinge pin 23, for example. It is also possible to use a stopper in the form of an arcuate plate whose radius is the distance between and the center of the connecting pin 52.

Further, in each of the above embodiments, the stopper 53
Although the above description has been given by taking as an example the case where it is configured to be detachably provided to the outer bracket 22A via the mounting cover 39, the present invention is not limited to this, and for example, a stopper may be attached to the outer bracket 22A via bolts or the like. It may be configured to be directly provided.

[0048]

As described in detail above, according to the invention of claim 1, the connecting pin is detached from the swing arm of the front bucket and the one end side of the bucket opening / closing cylinder in the outer bracket supporting the hinge pin together with the inner bracket. Since the stopper for restricting the connection pin is provided, even if the connecting pin is disengaged from the swing arm of the front bucket, the stopper can surely restrict the movement (disengagement) of the connecting pin, and the connecting pin is kept in the locked state. Can hold on.

Therefore, even if the connecting pin receives an excessive torque when the bucket opening / closing cylinder expands / contracts due to, for example, running out of grease, many parts can be prevented from being damaged by the expansion / contraction of the bucket opening / closing cylinder. The time and cost spent for replacement and the like can be greatly reduced, and at the same time, safety during work can be secured.

Further, according to the invention of claim 2, since the working opening is provided in the outer bracket and the stopper is provided in the outer bracket through the mounting cover covering the working opening, the mounting cover is provided. By removing the connecting pin from the swing arm of the front bucket through the work opening, you can easily perform maintenance and inspection work, and with the mounting cover covering the work opening of the outer bracket, The stopper can surely regulate the disengagement of the connecting pin.

Further, according to the invention of claim 3, since the connecting pin is formed to have a length corresponding to the distance between the inner bracket and the outer bracket, the distance between the stopper on the outer bracket side and the inner bracket is increased. Thus, the axial displacement of the connecting pin can be restricted, and the connecting pin can be reliably prevented from coming off from the swing arm or the like.

Further, according to the invention of claim 4, by providing another stopper on the inner bracket, the axial direction of the connecting pin between the stopper provided on the outer bracket and the other stopper provided on the inner bracket. The displacement can be regulated, and the connecting pin can be reliably prevented from coming off from the swing arm or the like.

[Brief description of drawings]

FIG. 1 is a partially broken external view showing an enlarged main part of a bottom dump type loader bucket according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a sectional view of the same position as FIG. 2 showing a second embodiment of the present invention.

FIG. 4 is an external view showing the front of a hydraulic excavator provided with a bottom dump type loader bucket according to the prior art.

FIG. 5 is an external view showing the loader bucket shown in FIG. 4 in an enlarged manner.

FIG. 6 is a front view of the loader bucket shown in FIG.

FIG. 7 is an external view showing an enlarged main part of the loader bucket shown in FIG.

8 is a sectional view taken along the line VIII-VIII in FIG.

9 is a view showing a state where the connecting pin shown in FIG. 8 is detached.
It is sectional drawing of a position similar to.

[Explanation of symbols]

 12 Rear Bucket 13 Front Bucket 18 Bucket Open / Close Cylinder 22A Outer Bracket 22B Inner Bracket 23 Hinge Pin 31 Swing Arm 38 Work Opening 39 Mounting Cover 52, 63 Connecting Pin 53 Stopper 61 Second Stopper (Other Stopper)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masayuki Ebisawa 40 Kamamitamari, Tamarimura, Shinji-gun, Ibaraki

Claims (4)

[Claims] 1. A rear bucket and a front bucket are rotatably connected by a hinge pin, and an oscillating arm provided on the front bucket is rotatably connected to one end of a bucket opening / closing cylinder via a connecting pin. A bottom dump type loader bucket in which the front bucket is opened and closed from the rear bucket when the bucket opening and closing cylinder is expanded and contracted. A bracket is provided, and the outer bracket is
A bottom dump type loader bucket, wherein a stopper is provided for restricting the connection pin from separating from one end side of the bucket opening / closing cylinder and a swing arm of the front bucket. 2. The outer bracket is provided with a working opening for detaching the connecting pin from one end side of the bucket opening / closing cylinder and a swing arm of the front bucket, and an attachment for detachably covering the opening. With a cover,
The bottom dump type loader bucket according to claim 1, wherein the stopper is provided on the outer bracket via the mounting cover. 3. The bottom dump type loader bucket according to claim 1, wherein the connecting pin is formed with a length corresponding to a distance between the outer bracket and the inner bracket. 4. The bottom dump type loader bucket according to claim 1, wherein the inner bracket is provided with another stopper that restricts axial displacement of the connecting pin between the inner bracket and the inner bracket.