JPH066808B2 - Excavator with extendable bucket - Google Patents

Description

The present invention relates to an excavator, and more particularly to an excavator characterized by allowing a bucket for excavating earth and sand to extend and contract in the length direction of an arm. The present invention relates to an excavator having a bucket.

[Conventional technology]

Conventionally, civil engineering work has often involved excavating earth and sand and excavating holes and grooves. An excavator (also called a backhoe) is actively used to modernize such civil engineering work and progress it efficiently.

In this excavator, a boom having a slightly V shape 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 is connected to the boom so as to be swingable up and down, and in many cases, a bucket is attached to the tip of the arm. With this configuration,
By operating the boom, arm, and bucket in cooperation with each other, it is possible to push the bucket into the ground and pull it up to dig up soil.

The basic structure of this excavator has not changed much, and normally, it was possible to excavate the earth and sand by operating each of the three hydraulic cylinders.

Then, in order to increase the depth of the groove or hole to be excavated by using the excavator having such a configuration, the length of the boom and the arm must be increased. Also, when the bucket is extended from the riverbank and the earth and sand is dug out, the length of the boom and arm is fixed, so the bucket does not reach beyond the set length. There was naturally a limit to the depth to be dug and the length to reach.

For this reason, in the case of deep digging or reaching the bucket to a long position, it is theoretically possible to lengthen the boom and the arm.

However, if the boom and arm are designed to be long, it is difficult to carry because the entire length becomes long when the excavator moves. Further, when the boom is vertically raised to turn the bucket after excavating the earth and sand, its height becomes high and it is dangerous because it comes into contact with an electric wire or a structure.

However, in civil engineering work, the length of the boom and arm is designed to be about the same as the conventional length to lower the bucket to a deep position in the hole or to move the bucket to a position further away from the vehicle body. Occasionally, there is a need for work to scrape and collect soil.

[Problems to be Solved by the Invention]

As described above, in the conventional excavator, the lengths of the boom and the arm are fixed, and only the action of jointly moving the connecting portions can be achieved. Therefore, it is impossible to extend the reach of the bucket from the vehicle body. It was a thing. Therefore, when digging deeply, an excavator having a long boom must be used, which is inconvenient for the work.

[Means for solving problems]

The present invention relates to 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, a hydraulic cylinder interposed between the bucket and the slider, and when the inner arm slides from the outer arm, slide the slider by the same length as the movement amount. The present invention provides an excavator having a retractable bucket, which is characterized by being configured with a synchronizing means.

[Action]

In the present invention, the outer arm is connected to the tip of the boom, and the inner arm is inserted inside the outer arm so as to be slidable in the longitudinal direction. Therefore, when trying to reach the deeper position of the bucket,
The telescopic mechanism pushes the inner arm out of the outer arm to increase the overall length, which allows the bucket to reach a deeper position or a longer distance. When the inner arm is extended from the outer arm, the base of the hydraulic cylinder that controls the angle of the bucket is moved by the same length by the synchronizing mechanism, so that the distance that the inner arm moves from the outer arm is the same. Since the hydraulic cylinder moves the distance of, it is possible to obtain the same operation feeling as a normal excavation operation.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

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

Crawlers 2 are attached to the lower left and right sides of a vehicle body 1 that houses an engine, a hydraulic pressure generator, and the like, and the crawler 2 allows the vehicle body 1 to move freely. A boom 3 bent in a slightly V-shape is connected to the center of the front surface of the vehicle body 1, and the center of the boom 3 and the front portion of the vehicle body 1 are connected by a depression hydraulic cylinder 4.

And, the outer arm 5 which is linear at the tip of the boom 3
Is swingably connected, and a hydraulic cylinder 6 for angle correction is provided between the rear portion of the outer arm 5 and the rear surface of the boom 3.
Is intervened. The outer arm 5 has a tubular shape with a quadrangular cross section made by bending a steel plate, and an inner arm 7 having a quadrangular cross section is inserted inside the outer arm so as to be able to move back and forth along the length direction. A bucket 8 is swingably connected to the tip of the inner arm 7.

Then, levers 9 and 10 for forming a link mechanism are attached to the front end of the inner arm 7 and the rear portion of the bucket 8, and both levers 9 and 10 have their ends tied together to form a slightly triangular shape. A cylinder rod 12 of a bucket cylinder 11 is connected to the apexes of the levers 9 and 10. Guide plates 13 as L-shaped cross-section guide rails are fixed to the left and right corners of the upper surface of the outer arm 5, and a slider 14 is attached to each of the guide plates 13 so as to be movable along its length. It has been inserted. A pair of trapezoidal shaft support plates 15 are fixed on the upper surface of the slider 14 with a space therebetween, and the base of the bucket cylinder 11 is inserted between the shaft support plates 15 so that the shaft support plates 15 The bucket cylinder 11 and the bucket cylinder 11 are swingably connected by a pin 16.

Next, FIG. 2 shows the internal structure and the synchronizing mechanism of the outer arm 5 in this embodiment. FIG. 3 is a sectional view showing a state in which the inner arm 7 is pushed out from the outer arm 5 in the structure shown in FIG. And FIG. 4 shows the second
FIG. 5 is a sectional view taken along the line AA in the figure, and FIG. 5 is an exploded perspective view of the synchronizing mechanism in the present embodiment.

A hydraulic cylinder 17 for expansion and contraction is inserted in the center of the inside of the inner arm 7 so as to be parallel to the longitudinal direction thereof, and the base of the hydraulic cylinder 17 is the rear end of the outer arm 5 (the right side in FIG. 2). ), And the cylinder rod 18 of the hydraulic cylinder 17 is connected to the center of the inner arm 7.

Next, a sprocket wheel 20 as a first wheel is pivotally supported at the tip of the outer arm 5, and a sprocket wheel as a fourth wheel is provided at the center of the rear part (right side in FIG. 2) of the outer arm 5. 21 are respectively supported. The tip of the chain 22 as the first connecting band is connected to the slider 14, and the chain 22 is turned over by the sprocket wheel 20 so that the outer arm 5 and the inner arm 7 can be rotated.
The other end is connected to the rear end of the inner arm 7 after passing through the space, inverted by the sprocket wheel 21, and wound in an S-shape. A sprocket wheel 23 as a third wheel is pivotally supported on the upper end of the rear end of the outer arm 5 so as to be half exposed on the upper surface of the outer arm 5. A sprocket wheel 24 serving as a second wheel is provided outside the arm 7.
Is pivotally supported on the outer arm 5. Then, the tip of the chain 25 as the second connecting band is connected to the slider 14, the chain 25 is inverted by the sprocket wheel 23, inserted between the outer arm 5 and the inner arm 7, and extended in the bucket 8 direction. Then, after being inverted by the sprocket wheel 24 and wound in a slightly S shape, its rear end is connected to the rear portion of the inner arm 7.

Next, the operation of this embodiment will be described.

By driving the crawler 2, the vehicle body 1 is moved to a place where a groove or a hole is to be dug down. Then, the bucket 8 is aligned with the position to be dug, and the hydraulic cylinders 4, 6, 11 are operated in cooperation with each other to swing the bucket 8 up and down, and the bucket 8 can dug earth and sand. This operation is the same as that of the conventional excavator.

Next, when deepening the hole or groove to be dug, the bucket 8 must be moved to a deeper position. In this case, hydraulic pressure is supplied to the hydraulic cylinder 17 to push out the cylinder rod 18. Then, the hydraulic cylinder 17 and the cylinder rod 18 are extended to push the inner arm 7 out of the outer arm 5, and the inner arm 7 slides as shown in FIGS. Therefore, the bucket 8 moves to a position longer than the base of the outer arm 5, so that the bucket 8 can be dug down to a deep position.

At this time, when the inner arm 7 moves with respect to the outer arm 5, the chain 22 is pulled, the chain 22 is reversed via the sprocket wheel 21, and is reversed again by the sprocket wheel 20, and the slider 14 is moved to the outer arm 5. It will be moved toward the opening end of. When the slider 14 is moved, both ends of the slider 14 are slid and guided by the guide plates 13, so that the bucket cylinder 11
At the same time as the movement of the inner arm 7, the movement amount is synchronized with the movement amount.

Thus, when the hydraulic cylinder 17 is operated and the cylinder rod 18 is pushed out, the inner arm 7 is pushed out from the outer arm 5, but since the bucket cylinder 11 is moved at the same time, the holding angle of the bucket 8 is the same. Since the vehicle moves while being maintained at, the operation of the excavation can be performed without any discomfort.

When pulling up the earth and sand excavated by the bucket 8, the hydraulic cylinder 17 is first operated to reduce the cylinder rod 18. Then, the inner arm 7 is pulled inward of the outer arm 5. At this time, since the chain 17 is connected to the rear part of the inner arm 7, the chain 25 is pulled toward the base of the outer arm 5,
The chain 25 is turned upside down by the sprocket wheel 24, further turned upside down by the sprocket wheel 23, and pulled to pull up the slider 14 toward the base of the outer arm 5.

For this reason, when the inner arm 7 is moved in the same manner as described above, the bucket cylinder 11 is also synchronously pulled and moved by the same amount of movement, and the holding angle of the bucket 8 is pulled up with the same holding angle. Sediment never falls. After that, the hydraulic cylinders 4 and 6 and the bucket cylinder 11 are operated in cooperation with each other to load and unload the earth and sand excavated by the bucket 8 onto a truck waiting behind the vehicle body 1 or to another location. be able to.

Next, FIG. 6 shows another embodiment of the synchronizing mechanism in this embodiment. In the drawings, the same mechanism is given the same reference numeral as that of the first embodiment, and the description thereof is omitted.

FIG. 6 is a side sectional view of the synchronizing mechanism in the second embodiment, FIG. 7 is a sectional view taken along line BB in FIG. 6 of the same, and FIG. 8 is an exploded perspective view of the synchronizing mechanism.

A recess 30 is formed in the center of the upper surface of the inner arm 7 along the lengthwise direction thereof, and a first rack 31 is fixed to the bottom of the recess 30. Further, a window hole 32 is opened at the center of the upper portion of the outer arm 5, and a shaft support plate 33 is fixed in parallel with the left and right sides of the window hole 32 toward the recess 30. A first pinion 36 and a second pinion 37 are axially supported on the shaft support plate 33 by shafts 34 and 35, respectively. The pinion 36 is meshed with the rack 31, and both the pinions 36 and 37 are respectively engaged. Intermeshed with each other. In addition,
The upper tooth surface of the pinion 37 is projected from the upper surface of the outer arm 5.

Next, between the pair of guide plates 13, guide bodies 38 and 39 are slidably inserted in the front and the rear, respectively, and a second rack 40 is provided between the guide bodies 38 and 39. It is connected so that its tooth surface faces downward, and guides 38, 39, rack 40
It is assembled in H shape by. This guide 38, 3
9. The rack 40 is guided by the guide plate 13 and moved along the length direction of the outer arm 5. The rack 40 is meshed with the pinion 37. And the slider
The lower part of 14 is cut so as to have a slightly U-shaped shape, the rack 40 is inserted into the U-shaped space, and the slider 14 is connected to the rack 40. The operation of the embodiment will be described.

When the inner arm 7 is to be pulled out from the outer arm 5, the hydraulic cylinder 17 is actuated and the cylinder rod
Push 18 out. Then, the inner arm 7 is pushed out from the outer arm 5, and the distance between the bucket 8 and the rear end of the outer arm 5 becomes long. Since the rack 31 moves at the same time that the inner arm 7 moves, the pinion 36 is rotated, and the rotation of the pinion 36 is reversed in the opposite direction by the pinion 37.
Passed to 40. Therefore, the rack 40 is guided by the guide bodies 38 and 39 and moves in the length direction of the guide plate 13. The moving direction and the moving amount of the rack 40 are the same as the moving direction and the moving amount of the inner arm 7.
The slider 14 connected to is moved by the same amount as the inner arm 7. Therefore, the moving amount of the bucket cylinder 11 fixed to the slider 14 is equal to the inner arm 7
And the inclination angle of the bucket 8 is always kept in the same state.

When the inner arm 7 is shortened and the bucket 8 is to be lifted, the cylinder rod 18 is retracted in the direction of the hydraulic cylinder 17 in the opposite direction to the inner arm 7 so that the inner arm 7 moves inward. Move to. Then, this moving operation is performed via the rack 31 and the pinion 36, 37.
40 is transmitted, and the slider 14 is returned by the same movement amount as the inner arm 7. For this reason, the inclination angle of the bucket 8 is always moved backward while maintaining a constant angle.

〔effect〕

Since the present invention is configured as described above, when performing the earth and sand excavation work using an excavator, it is possible to push down the bucket to a deeper position, or to reach a long distance, so in the earth and sand excavation work The work range can be widened.

And while the reach of this bucket can be extended, the length of the boom is the same as before, so if the boom is an obstacle when moving the excavator or turning the boom vertically. Therefore, it is possible to prevent the occurrence of accidents.

[Brief description of drawings]

FIG. 1 is a perspective view showing the appearance of an excavator showing an embodiment of the present invention, and FIG. 2 is a side sectional view showing the internal structure of an outer arm.
FIG. 3 is a side sectional view showing a state in which the above inner arm is pulled out from an outer arm, and FIG. 4 is a sectional view taken along the line AA in FIG.
FIG. 5 is an exploded perspective view showing the structure of the synchronizing mechanism, FIG. 6 is a side sectional view of an outer arm showing another embodiment of the present invention, and FIG. 7 is a sectional view taken along the line BB in FIG. , FIG. 8 is an exploded perspective view showing the structure of the synchronizing mechanism of the above. 1 ... Body, 3 ... Boom, 5 ... Outer arm, 7 ... Inner arm,
8 ... Bucket, 11 ... Bucket cylinder, 13 ... Guide plate as guide rail, 14 ... Slider, 17 ... Hydraulic cylinder, 20, 21, 23, 24 ... Sprocket wheel, 22,
25 ... Chain as connecting belt, 31 ... First rack, 36 ...
1st pinion, 37 ... 2nd pinion, 40 ... 2nd rack.

Claims (7)

[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 body. An inner arm slidably inserted into the arm, a bucket connected to the tip of the inner arm, a hydraulic cylinder for expansion and contraction interposed between the outer arm and the inner arm, and an outer arm The slider that can move in the length direction outside the slider, the hydraulic cylinder that is interposed between the bucket and the slider, and the slider that slides for the same length as the movement amount when the inner arm slides from the outer arm An excavator having a retractable bucket, the excavator having a retractable bucket. 2. The synchronizing means comprises first and second wheels pivotally supported on the tip of the outer arm, third and fourth wheels pivotally supported on the rear end of the outer arm, and a tip of the slider. , The rear end of the first arm and the fourth wheel are connected to the inner arm, and the flexible first connecting band wound around the first wheel and the fourth wheel in an S shape, and the tip of the connecting band is connected to the slider. Connect the end to the inner arm and attach S to the second and third wheels.
The excavator having an extendable bucket according to claim 1, wherein the excavator has a flexible second connecting band wound in a letter shape. 3. The excavator having an extendable bucket according to claim 2, wherein the connecting band is a chain. 4. The synchronizing means includes first and second pinions that are pivotally supported by an outer arm and mesh with each other, and a first rack that is fixed in a length direction of the inner arm and meshes with the first pinion. The excavator having an extendable bucket according to claim 1, wherein the excavator has an expandable bucket, which is fixed to a slider and is movable in a length direction of an outer arm, and is composed of a second rack that meshes with a second pinion. 5. The extendable bucket according to claim 1, wherein parallel rails are fixed in the lengthwise direction of the outer arm, and a slider is slid between the rails. Excavator having. 6. A pair of guide plates are placed in the lengthwise direction of the outer arm and fixed so as to be parallel to each other. A guide body is inserted through the guide plates so as to be slidable between the guide plates. The excavator having an extendable bucket according to claim 4, wherein the rack is fixed. 7. A window hole is opened in the middle of the outer arm, a second pinion is projected from the outer hole to the outside of the outer arm, and the second pinion is meshed with the second rack outside the outer arm. An excavator having a retractable bucket according to claim 4.