JPH09228406A - Excavating machine having expandable bucket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an excavating machine capable of reducing the number of drive components and simplifying the structure and operating smoothly in a stabilized manner. SOLUTION: This excavating machine comprises a movable body 11, a vertically rockable boom 13 connected to the body 11, a vertically rockable outside arm 15, which is hollow inside and connected to the boom 13 and an inside arm 17 which is slidably inserted into the outside boom 13 in the longitudinal direction. This excavating machine also comprises a bucket 18 connected to the tip of the inside boom 17, an expansion hydraulic cylinder interposed between the outside boom 15 and the inside boom 17, a slider 23, which is movable in the longitudinal direction outside the outside boom 15 and covers the whole outside boom 15 and whose length is rather identical to that of the outside boom 15, a hydraulic cylinder 21 interposed between the bucket 18 and the slider 23 and a connector 56 which connects the tip of the inside arm 17 to the tip of the slider 23 so that they may be integrally.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an excavator, and more particularly to an excavator having an extendable bucket characterized in that a bucket for excavating earth and sand can be extended and contracted in the length direction of an arm. is there.

[0002]

2. Description of the Related Art In civil engineering work, most of the work is excavating earth and sand and excavating holes. Excavators (also called bucket hoes) are actively used to modernize civil engineering work such as such excavation work and to efficiently carry out the work.

In many conventional excavators, a slightly character-shaped boom is swingably attached to a vehicle body to which a crawler and wheels are attached, and a slightly linear arm is attached to the tip of the boom. . This arm was vertically swingably connected to the boom, and a bucket was attached to the tip of the arm. With this configuration,
By operating the boom, arm, and bucket in cooperation with each other, the bucket can be pushed into the soil, and then the bucket can be pulled up to dig the earth and sand. The basic structure of this excavator has been actively used, and its shape has hardly changed. And these buckets, arms,
In order to operate the boom, the digging work can usually be performed by operating each of the three hydraulic cylinders.

Using such an excavator that has been widely used, it is necessary to lengthen the boom, the arm and the length in order to deepen the depth of the groove or hole to be dug. In addition, in the work such as extending the bucket from the river bank and digging the earth and sand on the opposite bank, the length of the boom and arm is fixed in the conventional excavator, so it is longer than the length set by the boom and arm. The bucket did not reach. As described above, in the conventional configuration, the depth to be dug by the bucket and the distance reached by the bucket are naturally limited.

[0005]

In the work under the limited conditions as described above, when the groove or hole is to be dug deeply or the bucket is to be reached to the long position, the boom and the arm are not to be reached. It is theoretically possible by increasing the length of each. However, if the boom and arm are designed to be long, the entire length of the boom and the arm will be long when the excavator moves, which makes it difficult to carry.

Further, after such excavation work, the excavated earth and sand must be moved from the front of the vehicle body toward the rear with a bucket. In this transfer, the bucket is rotated with respect to the vehicle body, but the boom must be raised vertically at the time of turning, and if the boom is raised vertically, the top height of the boom rises, and the electric wires and other This made it dangerous to work with because it came into contact with the structure.

In the conventional excavator, since the boom and the arm are fixed in length, the work range is limited. For this reason, the same applicant as the present invention proposes an excavator that allows the arm to be extended and retracted, and can push down the bucket attached to the tip of the arm to a deeper position or reach it for a long time ( Japanese Patent Publication No. 17173, 1573).

The newly proposed excavator has a movable body, a boom connected to the body so as to be vertically swingable, and a hollow interior connected to the boom so as to be vertically swingable. The outer arm, the inner arm inserted into the outer arm so as to be slidable in its length direction, the bucket connected to the tip of the inner arm, and the hydraulic pressure for expansion and contraction interposed between the outer arm and the inner arm. A cylinder, a slider that can move in the lengthwise direction outside the outer arm, and a hydraulic cylinder interposed between the bucket and the slider, so that the inner arm and the slider can move integrally,
These had a configuration in which a plurality of pulleys and a wire wound around the pulleys were connected to each other. With this structure, the expansion / contraction motion of the inner arm is transmitted as the movement of the slider outside the outer arm, and the bucket rotation cylinder is held by this slider, so that the entire arm can be moved without affecting the bucket angle. It has been made possible to extend and contract to deeply dig a groove or hole, or to move the bucket to a long position.

However, in such a structure, the integral movement of the inner arm and the slider needs to be performed in two directions, that is, the extension direction and the contraction direction of the arm. Therefore, in the above-mentioned configuration, the pulley and the wire are used for extending the arm. And two types are required for contraction. Also, these pulleys and wires must be placed inside the outer arm so that they do not get soiled. Therefore, there are problems that the number of parts such as the pulley and the wire is increased and that the structure is complicated by accommodating them in a narrow box-shaped arm. In addition, since the power transmission directions of the extension wire and the contraction wire are opposite to each other, the wire on the unused side may become loose, and the slider may be tilted with respect to the outer arm due to the short length of the slider. In some cases, various problems such as smooth discontinuity may occur.

The present invention has been made in view of the above circumstances, and has a retractable bucket that can reduce the number of driving parts and simplify the structure, and can perform stable and smooth operation. It is intended to provide an excavator.

[0011]

In order to solve the above-mentioned problems, in the present invention, a movable vehicle body, a boom connected to the vehicle body so as to be vertically swingable, and a vertically swingable body are provided. The outer arm is connected to the boom so that the inside is hollow, the inner arm is slidably inserted into the outer arm, the bucket is connected to the tip of the inner arm, and the inner arm is A hydraulic cylinder for expansion and contraction interposed between the arms, a slider that can move in the length direction outside the outer arm and covers the entire outer arm and has a length that is slightly the same as the outer arm, and a bucket and a slider. There is also provided an excavator having an extendable bucket composed of a hydraulic cylinder interposed therebetween and a connecting portion that connects the distal end side of the inner arm and the distal end side of the slider so as to be integrally movable. It is.

According to the present invention, the movable vehicle body, the boom connected to the vehicle body so as to be vertically swingable, and the hollow outer arm connected to the boom so as to be vertically swingable. An inner arm inserted into the outer arm so as to be slidable in the length direction, a bucket connected to the tip of the inner arm, and a hydraulic cylinder for expansion and contraction interposed between the outer arm and the inner arm. , A slider that can move in the length direction outside the outer arm and covers the slightly upper half of the outer arm and has a length slightly the same as the outer arm, and a hydraulic cylinder interposed between the bucket and the slider,
A connecting part that connects the tip side of the inner arm and the tip side of the slider so that they can move integrally, guide rails that project along both sides of the outer arm along the length direction, and slide and guide on this guide rail. The present invention provides an excavator having a retractable bucket, which comprises a slide frame formed on both lower ends of the slider.

Further, in the present invention, a plurality of protruding guides are provided on both sides of the inner arm so as to be retractable at intervals in the lengthwise direction, and these protruding guides are constantly urged in the protruding direction by springs. In addition, when the inner arm is in contact with the inner surface of both sides of the outer arm, it is retracted inside the inner arm against the spring, and when the inner arm slides out from the tip side of the outer arm, (EN) An excavator having an extendable bucket that projects toward one side and presses against the inner surface of each slide frame on both sides of the slider to function as a support portion of the slider.

Further, the projecting guide is constructed so that it can be retracted and retracted in a state of being rotated with respect to the inner arm with the rear end side as a fulcrum, and the spring compresses the projecting guide in the direction of rotating from the inner side to the outer side. Provided is an excavator having a retractable bucket characterized by comprising a coil spring.

Further, in the present invention, the projecting guide is constructed so as to be retractable from the inner arm in a slidable state, and the spring is a compression coil spring that presses the projecting guide in the direction of sliding from the inner side to the outer side. An excavator having a retractable bucket is provided.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

First, an excavator having a retractable bucket according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an external perspective view showing an embodiment of an excavator according to the present invention.

A vehicle body 1 containing an engine, a hydraulic pressure generator, etc.
Crawlers 12 are attached to the lower left and right sides of the vehicle 1, and the crawler 12 allows the vehicle body 11 to move freely. A boom 13 bent in a slightly V shape is connected to the center of the front surface of the vehicle body 11, and a hydraulic cylinder 14 for elevation is interposed between the center both sides of the boom 13 and the left and right front portions of the vehicle body. I am allowed. A linear outer arm 15 is swingably connected to the upper end of the boom 13, and a swing hydraulic cylinder 16 is interposed between the rear portion of the outer arm 15 and the center of the rear surface of the boom 13. is there. The outer arm 15 is formed by bending a steel plate and has a tubular shape with a slightly rectangular cross section. Inside the outer arm 15, an inner arm 17 having a quadrangular cross section so as to be slidable along its length direction is provided. It has been inserted. A bucket 18 is swingably connected to the tip of the inner arm 17.

A lever 1 for forming a link mechanism between the tip of the inner arm 17 and the rear portion of the bucket 18.
9 and 20 are connected, and both levers 19 and 20 are in a slightly triangular shape with their ends tied together, and the cylinder rod 22 of the bucket cylinder 21 is connected to the apex of both levers 19 and 20. There is. On the upper surface of the outer arm 15, a slider 2 that can move along its length is provided.
3, a pair of left and right shaft support plates 25 each having a slightly trapezoidal shape are fixed to the upper surface of the slider 23 at intervals. A base portion of a bucket cylinder 21 which is a hydraulic cylinder is inserted between both shaft support plates 25, and
5 and the bucket cylinder 21 are swingably connected by a pin 26.

Next, FIG. 2 is a view showing a cross-sectional structure of the arm with the bucket omitted, and FIG. 3 is a plan view of the arm without the bucket cylinder. Further, FIG. 4 is a view showing an assembled structure of the arm in which the tip portion of the inner arm is omitted, and FIG. 5 is a view showing a vertical section of the arm.

As shown in these figures, the outer arm 15 is open at the front end side (left end side in FIGS. 2, 3, and 4).
When the tip end side of the inner arm 17 inserted into the outer arm 15 appears and disappears through this opening, the entire arm expands and contracts. A pair of left and right roller insertion holes 3 are formed in the upper wall portion of the outer arm 15 on the front end side so as to penetrate the wall.
1 and 32 are formed, and these roller insertion holes 3
Upper guide rollers 3 for supporting the inner arms are provided at 1 and 32, respectively.
3, 34 are rotatably inserted in the direction in which the inner arm 17 appears and disappears. This inner arm support upper guide roller 3
3, 34 are respectively supported on the upper wall of the outer arm 15 by bearings (not shown), and the respective inner arm supporting upper guide rollers 33, 34 make contact with the outer surface of the upper wall of the inner arm 17 to rotate, The inner arm 17 is supported in the protruding / retracting direction.

Further, a pair of left and right roller insertion holes 35, 3 also penetrates through the lower wall portion of the outer arm 15 on the tip side thereof.
6 are formed, these roller insertion holes 35, 3
6 to the lower guide rollers 37 and 3 for supporting the inner arm, respectively.
8 is rotatably inserted in the direction in which the inner arm 17 appears and disappears. Lower guide rollers 37, 3 for supporting the inner arm
8 are also supported by the lower wall of the outer arm 15 by bearings (not shown), and the inner arm supporting lower guide rollers 37 and 38 come into contact with the outer surface of the lower wall of the inner arm 17 to rotate, whereby the inner arm is rotated. 17 is supported in the protruding / retracting direction.

Further, a telescopic hydraulic cylinder 39 is interposed between the outer arm 15 and the inner arm 17. This telescopic hydraulic cylinder 39 has axes of both arms 15, 1.
7 is inserted into the inner arm 17 in a state of being aligned with the center position of the inner arm 17, and the base end portion of the cylinder body penetrates the base end side of the inner arm 17 (right end side in FIGS. 2, 3, and 4). Then, it is located in the base end portion of the outer arm 15 (also in the right end portion in FIGS. 2, 3, and 4). Cylinder connecting pins 40 and 41 project from both sides of the base end of the cylinder body, and the tips of the cylinder connecting pins 40 and 41 are connected to the inner surface of the base end of the outer arm 15. On the other hand, the cylinder rod 42 of the hydraulic cylinder 39 for expansion and contraction
Of the inner arm 17 is located slightly in the middle of the inner arm 17 in the maximum retracted state. Cylinder rod connecting pins 43, 4 are provided on both sides of the tip of the cylinder rod 42.
4 protrudes, and the cylinder rod connecting pins 43, 44
Of the outer arm 15 are connected to the inner surface of the base end portion of the outer arm 15. By driving the hydraulic cylinder 39 for expansion and contraction, the inner arm 17 connected to the tip end portion of the cylinder rod 42 appears and disappears on the tip end side of the outer arm 17.

As described above, the slider 23 is provided outside the outer arm 15. The slider 23 includes an upper wall portion 51 that covers the entire upper side of the upper wall of the outer arm 15, side wall portions 52 and 53 that covers the outer sides of the entire side walls of the outer arm 15, and both side portions of the lower wall of the outer arm 15. And both lower wall portions 54 and 55 that cover. That is, the cross section of the slider 23 is slightly quadrangular as a whole, but has a shape in which the central portion of the lower surface is removed. The slider 23 has a length that is slightly the same as that of the outer arm 15, and has a shape that substantially covers the entire portion of the outer arm 15 excluding the central portion of the lower wall thereof. Inside the front end portion (left end portion in FIGS. 2, 3, and 4) of the slider 23, a square frame-shaped connecting frame 56 is integrally provided. The inner edge of the connecting frame 56 is integrally joined to the outer peripheral surface of the tip portion of the inner arm 17 protruding from the outer arm 15 by welding or the like. Accordingly, when the inner arm 17 projects from the outer arm 15, the operation is transmitted to the slider 23 via the connecting frame 56, and the slider 23 is synchronized with the inner arm 17 to the front end side outside the outer arm 15. It will become a slide. Further, when the inner arm 17 is retracted into the outer arm 15, the operation is transmitted to the slider 23 via the connecting frame 56, and the slider 23 is synchronized with the inner arm 17 on the rear end side outside the outer arm 15. It will slide into.

The upper wall portion 51 of the rear end portion of the slider 23 (the left end portion of FIGS. 2, 3, and 4) penetrates through the wall and has a left and right side.
Paired roller insertion holes 61 and 62 are formed, and upper slide guide rollers 63 and 64 are rotatably inserted into these roller insertion holes 61 and 62, respectively. The upper slide guide rollers 63 and 64 are supported by the upper wall portion 51 of the slider 23 by bearings (not shown), and the upper slide guide rollers 63 and 64 contact the outer surface of the upper wall portion 52 of the outer arm 15. When the slider 23 rotates,
It is slidably supported in the length direction.

Similarly, a pair of left and right roller insertion holes 65 and 66 are formed in the lower wall portions 54 and 55 of the rear end portion of the slider 23 so as to penetrate through the walls. Lower guide rollers 67 and 68 for sliding are rotatably inserted into 66, respectively. The lower slide guide rollers 67, 68 are supported on the lower wall portions 54, 55 of the slider 23 by bearings (not shown), and the lower slide guide rollers 67, 6 are respectively supported.
The slider 23 is supported slidably in the longitudinal direction of the outer arm 15 by the rotation of the outer arm 15 in contact with the outer surface of the lower wall of the outer arm 15. Therefore, by the rotation guide action of the upper slide guide rollers 63, 64 and the lower slide guide rollers 67, 68, the synchronous forward slide operation of the slider 23 when the inner arm 17 projects from the outer arm 15, The synchronous backward sliding operation of the slider 23 when the arm 17 is retracted into the outer arm 15 is smoothly performed.

On the upper surface of the slider 23, at a slightly central position,
A rectangular flat shaft support plate mounting plate 71 is integrally fixed by welding or the like. This shaft support plate mounting plate 71
The pair of shaft support plates 24 and 25 described above are fixed in parallel so as to stand up by welding or the like. Shaft support plates 24, 25
The support holes 72 and 73 for supporting the bucket cylinder 21 are formed in each of the support holes 72 and 7.
3 is a pin 74 provided at the base end of the bucket cylinder 21.
Is inserted and supported. As a result, the bucket cylinder 21 also moves back and forth in the length direction of the outer arm 15 in synchronization with the slider 23. Therefore, when the bucket 18 provided at the tip of the inner arm 17 moves to the front of the arm as the inner arm 17 advances, the bucket cylinder 21 for controlling the swing angle of the bucket 18 also moves outside the slider 23. Since the slide advancing on the arm 15 advances in synchronization with the inner arm 17, the angle of the bucket 18 is kept constant. That is, since the bucket 18 does not change its angle due to the expansion and contraction of the arm, even if the arm is expanded or contracted while holding the soil or the like in the bucket 18, the bucket 18 may unexpectedly swing. There is no risk of the earth falling.

Next, the operation of the present embodiment will be described.

The crawler 12 is driven to move the vehicle body 11 to a place where a groove or hole is to be dug down. And
The bucket 18 is aligned with the position to be dug, the buckets 18 are moved by operating the hydraulic cylinders 14, 15, 21 in cooperation with each other, and the bucket 18 can dug earth and sand. Next, in order to deepen the hole or groove to be dug, the bucket 18 must be controlled to move to a deeper position. In this case, the telescopic hydraulic cylinder 39 is operated to move the cylinder rod 4
Push out 2. Then, the expansion / contraction hydraulic cylinder 39 and the cylinder rod 42 extend so that the inner arm 17 is pushed out of the outer arm 15 and the inner arm 17 slides from the outer arm 15. Therefore, bucket 1
Since 8 moves to a position longer than the base of the outer arm 15, the bucket 18 can be dug down to a deep position.

In this operation, when the inner arm 17 moves with respect to the outer arm 15, the slider 23, which is connected to the tip of the inner arm 17 via the connecting frame 56, integrally operates to move the outer arm 17. It will be slid in the length direction of 15. At this time, the slider 23 moves the outer arm 15
Since it has a shape that covers the whole of the above and has a length that is slightly the same as that of the outer arm 15, it will not come off from the outer arm 15.
Further, since the inner arm 17 and the slider 23 are constantly connected via the connecting frame 56, as long as the inner arm 17 is moved by the hydraulic cylinder 39 for expansion and contraction,
The same amount of movement is performed in synchronization with the movement of the inner arm 17.

In this way, when the telescopic hydraulic cylinder 39 is actuated and the cylinder rod 42 is pushed out, the inner arm 17 is pushed out from the outer arm 15,
Since the bucket cylinder 21 is simultaneously moved in synchronization with its sliding amount, the bucket 18 is moved while being held at the same angle, and the bucket 18 can be operated without any discomfort during the excavation operation.

When the earth and sand dug up by the bucket 18 is pulled up, first, the hydraulic cylinder 3 for expansion and contraction is used.
9 is operated to reduce the cylinder rod 42. Then, the inner arm 17 is pulled inward of the outer arm 15. At this time, since the slider 23 is integrally connected to the tip of the inner arm 17 via the connecting frame 56, the slider 23 is pulled up to the base end side of the outer arm 15.

Therefore, similarly to the above, at the same time that the inner arm 17 moves, the bucket cylinder 21 also moves synchronously and moves at the same speed. Therefore, the bucket 18 is pulled up with the holding angle kept the same, so that the excavated earth and sand is not dropped. After that, by operating the hydraulic cylinders 14 and 16 and the bucket cylinder 21 in cooperation with each other, the earth and sand excavated by the bucket 18 is transferred to a truck that stands by behind the vehicle body 11 or moved to another place. Can be changed.

According to the above embodiment, unlike the construction of the conventional excavator having the expandable bucket which the applicant has already proposed, the slider 23 is connected to the inner arm 17 without using many pulleys and wires. Since they are connected by 56, the number of parts for driving the extension and contraction of the arm can be greatly reduced, and the structure can be simplified. Moreover, since the operation can be performed stably and smoothly as described above, the workability can be improved.

Next, an excavator having a retractable bucket according to another embodiment of the present invention will be described with reference to FIGS.

FIG. 6 is an external perspective view showing an embodiment of an excavator according to the present invention.

A vehicle body 1 containing an engine, a hydraulic pressure generator, etc.
Crawlers 112 are attached to the lower left and right of 11 and the vehicle body 111 can be freely moved by these crawlers 112. A boom 113, which is bent in a V-shape, is connected to the center of the front surface of the vehicle body 111, and a hydraulic cylinder 114 for ascending and descending is provided between the center both sides of the boom 113 and the front left and right sides of the vehicle body. Is intervened. A linear outer arm 115 is swingably connected to the upper end of the boom 113.
A rocking hydraulic cylinder 116 is interposed between the rear portion and the center of the rear surface of the boom 113. This outer arm 1
Reference numeral 15 denotes a tubular shape in which a steel plate is bent to have a slightly rectangular cross section, and the inside of the outer arm 115 has a rectangular cross section so that it can slide along its length direction.
17 is inserted. A bucket 118 is swingably connected to the tip of the inner arm 117.

The tip of the inner arm 117 and the bucket 11
The levers 119 and 120 for forming a link mechanism are connected between the rear portion of the lever 8 and the rear portion of the lever 8.
0 has a slightly triangular shape in which the ends thereof are tied together, and the cylinder rod 122 of the bucket cylinder 121 is connected to the apexes of both levers 119 and 120. A slider 123 that can move in the length direction is combined with the upper surface of the outer arm 115, and a pair of left and right shaft support plates 125 that are slightly trapezoidal are fixed to the upper surface of the slider 123 at intervals. . Double shaft support plate 12
Bucket cylinder 1 which is a hydraulic cylinder between 5
The base portion 21 is inserted, and the shaft support plate 125 and the bucket cylinder 121 are swingably connected by a pin 126.

Next, FIG. 7 is a diagram showing the cross-sectional structure of the arm with the bucket omitted, and FIG. 8 is a diagram showing the planar structure of the arm without the bucket cylinder. Further, FIG. 9 is a view showing an assembled structure of the arm in which the tip portion of the inner arm is omitted, and FIG. 10 is a view showing a vertical cross section of the arm. Further, FIG. 11 is a view showing the structure of the protrusion guide, and FIG. 12 is an enlarged cross-sectional view showing the protrusion guide.

As shown in these figures, the outer arm 115
Is open at the front end side (left end side in FIGS. 2, 3, and 4), and the front end side of the inner arm 117 inserted into the outer arm 115 is retracted through this opening portion, whereby the entire arm expands and contracts. It is supposed to do. A pair of left and right roller insertion holes 131 and 132 are formed in the upper wall portion of the outer arm 115 on the front end side so as to penetrate the wall, and these roller insertion holes 131 and 132 are respectively formed in the inner arm support upper guides. The rollers 133 and 134 are rotatably inserted in the direction in which the inner arm 117 appears and disappears. The inner arm supporting upper guide rollers 133, 134 are supported on the upper wall of the outer arm 115 by bearings (not shown), and the inner arm supporting upper guide rollers 133,
The inner arm 117 is supported in the protruding / retracting direction when the inner arm 117 comes into contact with the outer surface of the upper wall of the inner arm 117 and rotates. Further, the lower wall portion of the outer arm 115 on the front end side also penetrates the wall to form a pair of left and right roller insertion holes 13.
5, 136 are formed, and the inner arm supporting lower guide rollers 137, 138 are rotatably inserted in the roller insertion holes 135, 136 in the direction in which the inner arm 117 appears and disappears. The inner arm supporting lower guide rollers 137 and 138 are also supported on the lower wall of the outer arm 115 by bearings (not shown), and the inner arm supporting lower guide rollers 137 and 138 are attached to the outer surface of the lower wall of the inner arm 117. By touching and rotating,
The inner arm 117 is supported in the protruding / retracting direction.

Further, a telescopic hydraulic cylinder 139 is interposed between the outer arm 115 and the inner arm 117. The expansion / contraction hydraulic cylinder 139 is inserted into the inner arm 117 in such a manner that the axial center thereof coincides with the center positions of the arms 115 and 117, and the base end portion of the cylinder body is the base end side of the inner arm 117. (Right end side of FIGS. 2, 3, and 4), and is located in the base end portion of the outer arm 115 (also right end portion of FIGS. 2, 3, and 4). Cylinder connecting pins 140 and 141 project from both sides of the base end of the cylinder body, and the tips of the cylinder connecting pins 140 and 141 are connected to the inner surface of the base end of the outer arm 115. On the other hand, the tip of the cylinder rod 142 of the telescopic hydraulic cylinder 139 is located slightly in the middle of the inner arm 117 in the maximum retracted state. Cylinder rod connecting pins 143 and 144 project from both sides of the tip of the cylinder rod 142, and the tips of the cylinder rod connecting pins 143 and 144 are connected to the inner surface of the proximal end portion of the outer arm 115. By driving the hydraulic cylinder 139 for expansion and contraction, the inner arm 117 connected to the tip end portion of the cylinder rod 142 is projected and retracted on the tip end side of the outer arm 117.

Further, both side walls 145 of the outer arm 115,
On the outer surface side of 146, guide rails 147 and 148 for guiding the slider 123 are provided so as to project outward. That is, each of the guide rails 14
7, 148 are made of steel material having a quadrangular cross section, and are located in the vertical direction on the outer surface side of both side walls 145, 146 of the outer arm 115, or in a middle portion thereof, and extend over the entire length of the outer arm, respectively. It has been extended for a long time. The slider 123 is guided by each of the guide rails 147 and 148 so as to be slidable along the length direction of the outer arm 115.

The slider 123 is provided outside the outer arm 115 as described above. This slider 1
23 is composed of an upper wall portion 151 that covers the entire upper side of the upper wall of the outer arm 115, and side wall portions 152 and 153 that cover the outside of the upper half of the side walls of the outer arm 115. That is, the slider 123 has a shape in which the side walls 152 and 153 hang down from both sides of the upper wall 151 and the lower surface is opened, and covers the upper side of the outer arm 115 to a little half. The slider 123 has the same length as the outer arm 115. The slide frame 1 slidably guided to the lower end portions of the side wall portions 152 and 153 of the slider 123 by the guide rails 147 and 148 of the side walls 145 and 146 of the outer arm 115 described above.
54 and 155 are formed. This slide frame 15
Nos. 4, 155 are made of a steel plate integrally with the slider 123 and have a U-shaped cross section with one side open, and the lower end of the side wall portion 15 of the slider is bent outward and then bent downward. Further, the lower end thereof is bent inward. Each of the slide frames 154 and 155 bent in the U-shape forms the side wall 14 of the outer arm 115.
5, 146, the guide rails 147 and 148 are fitted so as to cover the guide rails 147 and 148 from the outside, so that the slider 123 is different from the case of the one embodiment described above.
Although the outer arm 1 has a shape that covers only about half of the outer arm 5, the outer arm 1 is in a fitted and held state without falling off.
The sliding guide is stably guided in the length direction of 15.

Further, also in this other embodiment, the front end portion of the slider 123 (the left end portion in FIGS. 2, 3, and 4).
A square frame-shaped connecting frame 156 is integrally provided inside the. The inner edge of the connecting frame 156 has the outer arm 11
5 is integrally joined to the outer peripheral surface of the tip portion of the inner arm 117 protruding from No. 5 by welding or the like. Accordingly, when the inner arm 117 projects from the outer arm 115, the operation is transmitted to the slider 123 via the connecting frame 156, and the slider 123 is synchronized with the inner arm 117 to the front end side outside the outer arm 115. It will become a slide. In addition, the inner arm 117 is the outer arm 1
In the case of immersing in 15, the operation is transmitted to the slider 123 via the connection frame 156, and the slider 123 slides to the rear end side in synchronization with the inner arm 117 outside the outer arm 115. is there.

The rear end of the slider 123 (see FIGS. 2 and 3)
A pair of left and right roller insertion holes 161 and 162 are formed in the upper wall portion 151 (left end portion of FIG. 4) penetrating the wall, and these roller insertion holes 161 and 162 are respectively slid upper guide rollers. 163 and 164 are rotatably inserted. Upper guide roller for this slide 1
63 and 164 are sliders 12 by bearings not shown.
3 are respectively supported by the upper wall portion 151 of the outer arm 1.
The slider 123 is slidably supported in the length direction of the outer arm 115 by contacting with the outer surface of the upper wall portion 15 of the fifteen and rotating. Therefore, due to the rotation guide action of these upper guide rollers 163 and 164 for sliding, the synchronous forward slide operation of the slider 123 when the inner arm 117 projects from the outer arm 115, and the inner arm 117 is retracted into the outer arm 115. In this case, the synchronous backward sliding operation of the slider 123 is smoothly performed.

Further, in the excavator according to the other embodiment, as shown in FIGS. 11 and 12, a plurality of window holes 167 are formed in both sides of the inner arm 117 at intervals in the longitudinal direction. Projecting guides 168 are provided in the window holes 167 so as to be retractable. The protrusion guide 168 is made of, for example, a steel material and has a fan shape in a plan view and a thick plate shape in a side view, and the thickness thereof is slightly the same as the guide rail 147 of the outer arm 115. It is arranged on the inner arm 117 at the same height as the guide rail 147. The narrow ends of the protrusion guides 168 are arranged at the rear side of the window holes 167, respectively, and are supported by the inner arm 117 by the support shafts 169 so as to be rotatable in the lateral direction. It can project from the window hole 167 to the outside of the inner arm 117. Further, the protrusion guide 168 is constantly urged by a spring 170 formed of a compression coil spring or the like in a direction to protrude outward from the window hole 167. The spring 170 includes a spring holding member 171 provided in the inner arm 117 and a protruding guide 1.
It is held between spring holding frames 172 provided inside 68.

Then, as shown in the right part of FIG.
When the portion of the inner arm 117 having the protrusion guide 168 is located inside the outer arm 115, the protrusion guide 168 contacts the inner surfaces of both side portions of the outer arm 115, and in this state, the protrusion guide 168 causes the spring 170 to move. Against the inside of the inner arm 117. On the other hand, the inner arm 11
In a state in which 7 slides out from the tip side of the outer arm 115 and is exposed, as shown on the left side of FIG. 12, the U-shaped slide frames projecting to the outside of the inner arm 117 on both sides of the slider 123. The elastic force of the spring 170 presses the inner surface of the slide frame 154, respectively, and thus the slide frame 154
It is inserted into the inner surface of the slider and functions as a support portion of the slider 123.

That is, in this other embodiment,
Unlike the case of the above-described embodiment, the slider 123 is mounted so as to cover only the upper half of the outer arm 115, so that when the arm 123 extends, the slider 123 is mounted on the outer arm 1.
If the slider 15 is largely slid to the tip side, the length of the portion supported by the outer arm 115 becomes small, and it may be insufficient to maintain the linearity between the slider 123 and the outer arm 115. . Therefore, as described above, when the slider 123 largely moves from the outer arm 115, the protrusion guide 168 provided on the inner arm 117 is fitted to the slide frame 154 of the slider 123 to support the slider 123 at a plurality of positions. Thus, the linearity described above is maintained. The protrusion guide 168 is fan-shaped and is configured to protrude from the window hole 167 with its ridge line maintaining a constant inclination angle.
As a result, every time the inner arm 117 comes out of the outer arm 115, the inner arm 117 comes into and out of the window smoothly by coming into contact with the inner surface of the side wall of the outer arm 115.

A rectangular flat shaft support plate mounting plate 176 is integrally fixed to the upper surface of the slider 123 at a slightly central position by welding or the like. The pair of shaft support plates 124 and 125 described above are fixed to the shaft support plate mounting plate 176 in parallel so as to stand up by welding or the like. The bucket cylinder 12 is attached to the shaft support plates 124 and 125, respectively.
1. Support holes 177 and 178 for supporting 1 are opened,
The bucket cylinder 1 is inserted into these support holes 177 and 178.
A pin 179 provided at the base end of 21 is inserted and supported. As a result, the bucket cylinder 121 also moves forward and backward in the length direction of the outer arm 115 in synchronization with the slider 123. Therefore, when the bucket 118 provided at the tip of the inner arm 117 moves to the front of the arm as the inner arm 117 advances, the bucket 11
Bucket cylinder 12 for controlling the swing angle of 8
1 also advances in synchronization with the inner arm 117 by the slide advance of the slider 123 on the outer arm 115,
The angle of the bucket 118 is kept constant. That is, since the bucket 118 does not change its angle due to the expansion and contraction of the arm, the bucket 118 may unintentionally swing even when the arm is expanded or contracted while holding the soil or the like in the bucket 118. There is no risk of the earth falling.

Next, the operation of another embodiment having the above configuration will be described.

In this other embodiment as well, the crawler 112 is driven to move the vehicle body 111 to a place where a groove or hole is to be dug, as in the case of the one embodiment. Then, align the bucket 118 with the position where you want to dig,
The buckets 118 are moved by operating the hydraulic cylinders 114, 115 and 121 to cooperate with each other.
The earth and sand can be dug by 18.

Next, in order to deepen the hole or groove to be dug, the bucket 118 must be controlled to move to a deeper position. In this case, the expansion / contraction hydraulic cylinder 139 is operated to push out the cylinder rod 142. Then, the expansion / contraction hydraulic cylinder 139 and the cylinder rod 142 are extended to push the inner arm 117 out of the outer arm 115, and the inner arm 117 slides from the outer arm 115. Therefore, since the bucket 118 moves to a position longer than the base of the outer arm 115, the bucket 118 can be dug down to a deep position.

In this operation, when the inner arm 117 moves with respect to the outer arm 115, the slider 12 connected to the tip of the inner arm 117 via the connecting frame 156.
3 operates integrally and slides in the length direction of the outer arm 115. At this time, the slider 123
Is a shape that covers the upper half of the outer arm 115, but the slide frames 154 and 155 of the side wall portions 152 and 153 of the slider 123 are the guide rails 14 of the outer arm 115.
7 and 148 and slider 123
Has a length that is slightly the same as that of the outer arm 115, so that it does not come off from the outer arm 115. Also, the inner arm 1
Since the slider 17 and the slider 123 are constantly connected via the connecting frame 156, the hydraulic cylinder 139 for expansion and contraction is used.
Therefore, as long as the inner arm 117 is moving, the same movement amount is moved in synchronization with the movement of the inner arm 117.

In this way, when the hydraulic cylinder 139 for expansion and contraction is operated to push out the cylinder rod 142, the inner arm 117 is pushed out from the outer arm 115, but the bucket cylinder 121 is simultaneously moved in synchronization with the sliding amount. From that, the bucket 118
Since the angle of is moved while being held at the same angle, it can be operated without any discomfort during the excavation operation.

When the earth and sand dug up by the bucket 118 is pulled up, first, the expansion / contraction hydraulic cylinder 139 is operated to reduce the cylinder rod 142. Then, the inner arm 117 is pulled inward of the outer arm 15. At this time, since the slider 123 is integrally connected to the tip of the inner arm 117 via the connecting frame 156, the slider 123 is not connected to the outer arm 1.
It will be pulled up to the base end side of 15.

Therefore, similarly to the above, at the same time as the inner arm 117 moves, the bucket cylinder 121 also moves synchronously and moves at the same speed. Therefore, the bucket 118 is pulled up with the holding angle kept the same, so that the excavated earth and sand is not dropped. After that, the hydraulic cylinders 114 and 116 and the bucket cylinder 121 are operated in cooperation with each other, so that the earth and sand excavated by the bucket 118 is transferred to a truck waiting behind the vehicle body 111,
Or you can transfer it to another place.

Also according to the other embodiments described above, unlike the construction of the conventional excavator having a retractable bucket proposed by the applicant, the slider 123 is connected to the inner arm 117 without using a large number of pulleys or wires. Frame 156
Since the structure is connected by means of, the number of parts for driving the arm extension / contraction can be significantly reduced, and the structure can be simplified. Moreover, since the operation can be performed stably and smoothly as described above, the workability can be improved.

Further, in this other embodiment, the slider 123 is mounted so as to cover only the upper half of the outer arm 115, so that the slider 23 covers the entire outer arm 15 of the one embodiment. The weight of the slider 123 is smaller than in the case. Therefore, the extension / contraction operation of the arm can be performed more smoothly, and the weight of the entire arm can be reduced, so that the driving force required for swinging the arm can be reduced accordingly.

Further, when the slider 123 largely slides toward the distal end side of the outer arm 115 when the arm is extended, the length of the portion supported by the outer arm 115 becomes small, and the slider 123 and the outer arm 115 have linearity. However, when the slider 123 is largely moved from the outer arm 115 as described above, the protrusion guide 1 provided on the inner arm 117 may be insufficient.
Since 68 is fitted to the slide frame 154 of the slider 123 to support the slider 123 at a plurality of positions, the linearity can be reliably maintained, and the entire arm does not bend downward. Moreover, the protrusion guide 1
When the inner arm 117 is located inside the outer arm 115, 68 does not get in the way and does not interfere with the inner arm 117.
Spring 17 when 7 extends from outer arm 115
No special mechanism or operation is required because it automatically projects with a zero elastic force and exerts a guide function. Therefore, it is possible to obtain advantages such as a simple structure.

FIG. 13 shows a modification of the protrusion guide as still another embodiment. The protrusion guide 168 shown in FIG.
Although it was supported so as to be rotatable via 9,
In the embodiment shown in FIG. 13, the protrusion guide 181 is configured to be linearly slid from the inner arm 117 and can be retracted and retracted from the window hole 182. That is, the protrusion guide 18
1 has a slightly quadrangular or trapezoidal shape in a plan view, and this protruding guide 181 is slidably accommodated in an internal cylindrical holder 183. In addition, the spring 184 is a spring holding member 185 provided in the inner arm 117.
And the spring holding frame 1 provided on the protrusion guide 181.
86 is a compression coil spring supported by 86 and is adapted to press the protruding guide in a direction of sliding from the inside to the outside.

Then, as shown in the right part of FIG.
When the portion of the inner arm 117 having the protrusion guide 168 is located inside the outer arm 115, the protrusion guide 168 contacts the inner surfaces of both side portions of the outer arm 115, and in this state, the protrusion guide 168 causes the spring 1184. Against the inside of the inner arm 117. On the other hand, the inner arm 1
In a state in which 17 slides out from the tip side of the outer arm 115 and is exposed, as shown on the left side of FIG. 13, the U-shaped slide frames on both sides of the slider 123 project outward of the inner arm 117. The inner surface of the slide frame 15 is pressed against the inner surface of the slide frame 154 by the elastic force of the spring 118.
4 is fitted and inserted into the inner surface of the slider 4, and functions as a support portion of the slider 123.

With the configuration shown in FIG. 13 as well, the same operational effect as that of the embodiment shown in FIG. 12 can be obtained.

[0063]

As described above, according to the excavator having the expandable bucket according to the present invention, the slider is made to have the same length as the outer arm so that the slider is integrally operated by the inner arm and the connecting portion. Since the pulleys and wires are omitted, the number of parts constituting the drive mechanism for expanding and contracting the bucket can be significantly reduced, and the structure can be simplified.
Also, without causing problems such as loose wires,
The operation can be performed stably, smoothly, and accurately, the bucket expanding / contracting operation becomes more reliable, and an excellent effect in practical use can be achieved.

[Brief description of drawings]

FIG. 1 is an external perspective view showing an embodiment of an excavator according to the present invention.

FIG. 2 shows an embodiment of an excavator according to the present invention and is a cross-sectional view of an arm with a bucket omitted.

FIG. 3 shows an embodiment of an excavator according to the present invention, and is a plan view of an arm in which a bucket cylinder is omitted.

FIG. 4 shows an embodiment of an excavator according to the present invention, and is an assembly configuration diagram of an arm in which a tip portion of an inner arm is omitted.

FIG. 5 shows an embodiment of an excavator according to the present invention, and is a longitudinal sectional view of an arm.

FIG. 6 is an external perspective view showing another embodiment of the excavator according to the present invention.

FIG. 7 shows another embodiment of the excavator according to the present invention, and is a cross-sectional view of an arm without a bucket.

FIG. 8 shows another embodiment of the excavator according to the present invention, and is a plan view of an arm in which a bucket cylinder is omitted.

FIG. 9 shows another embodiment of the excavator according to the present invention, and is an assembly configuration diagram of an arm in which a tip portion of an inner arm is omitted.

FIG. 10 shows another embodiment of the excavator according to the present invention, and is a longitudinal sectional view of an arm.

FIG. 11 shows another embodiment of the excavator according to the present invention, and is a perspective view showing a configuration of a protrusion guide.

FIG. 12 shows another embodiment of the excavator according to the present invention, and is an enlarged transverse cross-sectional view showing the structure of the protrusion guide.

FIG. 13 shows still another embodiment of the excavator according to the present invention, and is a lateral cross-sectional view showing a modification of the protrusion guide in an enlarged manner.

[Explanation of symbols]

 11 Vehicle Body 13 Boom 15 Outer Arm 17 Inner Arm 18 Bucket 21 Bucket Cylinder 22 Cylinder Rod 23 Slider 39 Telescopic Hydraulic Cylinder 42 Cylinder Rod 56 Connecting Frame 111 Vehicle Body 113 Boom 115 Outer Arm 117 Inner Arm 118 Bucket 121 Bucket Cylinder 122 Cylinder Rod 123 Slider 139 Hydraulic cylinder for expansion and contraction 142 Cylinder rod 147 Guide rail 154 Slide frame 155 Slide frame 156 Connection frame 168 Projection guide 170 Spring 181 Projection guide 184 Spring

Claims (5)

[Claims] 1. A movable vehicle body, a boom connected to the vehicle body so as to be vertically swingable, an outer arm having a hollow interior connected to the boom so as to be vertically swingable, and an outer arm. The inner arm inserted so that it can slide in the longitudinal direction, the bucket connected to the tip of the inner arm, the hydraulic cylinder for expansion and contraction interposed between the outer arm and the inner arm, and the outer arm A slider that can move in the length direction on the outside and covers the entire outer arm and has a length that is slightly the same as the outer arm, a hydraulic cylinder interposed between the bucket and the slider, and a tip side of the inner arm and the slider. An excavator having an extendable bucket, which is composed of a connecting portion that connects the tip end side so as to be integrally movable. 2. A movable vehicle body, a boom connected to the vehicle body so as to be vertically swingable, an outer arm having a hollow interior connected to the boom so as to be vertically swingable, and an outer arm. The inner arm inserted so that it can slide in the longitudinal direction, the bucket connected to the tip of the inner arm, the hydraulic cylinder for expansion and contraction interposed between the outer arm and the inner arm, and the outer arm A slider that can move in the length direction on the outside and covers the upper half of the outer arm and has the same length as the outer arm; a hydraulic cylinder interposed between the bucket and the slider; and a tip side of the inner arm. A connecting part that connects the tip side of the slider so that it can move integrally, a guide rail that projects along both sides of the outer arm along the length direction, and a slider that is slidably guided by the guide rail. An excavator having a retractable bucket, characterized in that the excavator is configured with slide frames formed on both lower ends of both sides. 3. A plurality of protruding guides are provided on both sides of the inner arm so as to be capable of projecting and retracting at intervals in the length direction, and each of the protruding guides is constantly urged in the protruding direction by a spring and the outer arm is When the inner arm is in contact with the inner surface of both sides, it is recessed inside the inner arm against the spring, and when the inner arm slides out from the tip side of the outer arm and protrudes to the outside of the inner arm. The excavator having an extendable bucket according to claim 2, wherein the excavator has a retractable bucket and is pressed against inner surfaces of the slide frames on both sides of the slider to function as a support portion of the slider. 4. The projecting guide is configured to be retractable in a state of being rotated with respect to the inner arm with its rear end side as a fulcrum,
The excavator having an extendable bucket according to claim 3, wherein the spring is a compression coil spring that presses the protrusion guide in a direction of rotating the protrusion guide from the inside toward the outside. 5. The projection guide is configured to be retractable in a state of sliding from the inner arm, and the spring is composed of a compression coil spring that presses the projection guide in a sliding direction from the inside to the outside. An excavator having an extendable bucket according to claim 3.