JPH07259114A - Telescopic arm device for construction equipment - Google Patents

Abstract

PURPOSE:To obtain sufficient strength, and to contrive a minimum weight of a telescopic arm by forming an outer arm so as to be formed in a tapered box shape toward the front end section from the base end section. CONSTITUTION:An outer arm 24 is formed so that the base end section is formed in a box shape and the outer arm 24 is formed in a tapered box shape in a side view toward the front end section, a square-shaped cylindrical guide frame 45 parallel with the underside plate of the outer arm 24 is mounted on the inside of the outer arm 24, and an inner arm 25 is installed slidably on the inside of the guide frame 45 by a telescopic hydraulic cylinder 26. A guide plate is set up to the inclined top face section of the outer arm 24, and the sliding base section 35 of a bucket-cylinder base-end section bracket 27 is fitted slidably in the longitudinal direction along the guide plate. Pins 36 fixed to the left and right side face sections of the sliding base section 35 and a rod end pin pivotally attached to the front section of the inner arm 25 are connected by a connecting rod 28. Accordingly, the outer arm 24 is given sufficient strength and can be manufactured in minimum weight, and the strength and weight of the inner arm 25 inserted to the guide frame 45 can made rationally satisfactorily.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a telescopic arm device for a work attachment mounted on construction machines such as hydraulic excavators and work vehicles.

[0002]

2. Description of the Related Art FIG. 6 is a perspective view of an excavator disclosed in Japanese Patent Laid-Open No. 3-110220. Figure 6
As shown in FIG. 3, crawlers 2 are attached to the lower left and right sides of the vehicle body 1, and the crawler 2 allows the vehicle body 1 to move freely. And, a boom 3 bent in a slightly V shape is connected to the center of the front surface of the vehicle body 1,
A hydraulic cylinder 4 for depression is interposed between the center legs of the boom 3 and the left and right front portions of the vehicle body 1. A direct outer arm 5 is swingably connected to the upper end of the boom 3,
A swinging hydraulic cylinder 6 is interposed between the rear portion of the outer arm 5 and the center of the rear surface of the boom 3. The outer arm 5 is formed by bending a steel plate and has a tubular shape with a slightly quadrangular cross section, and an inner arm 7 having a quadrangular cross section is inserted inside the outer arm so as to be slidable along its length direction. I am allowed. A bucket 8 is swingably connected to the tip of the inner arm 7. Lever 9, 10 for forming a link mechanism is connected between the tip of the inner arm 7 and the rear part of the bucket 8, and both levers 9,
Reference numeral 10 has a slightly triangular shape in which the ends thereof are tied together, and a cylinder rod 12 of a bucket cylinder 11 is connected to the apexes of both levers 9 and 10. On the upper surface of the outer arm 5, there is combined a slider 13 which can move in the length direction thereof, and on the upper surface of the slider 13, a pair of slightly trapezoidal shaft supporting plates are fixed at intervals. . The base of the bucket cylinder 11 is inserted between the two shaft support plates 15, and the shaft support plate 15 and the bucket cylinder 11 are swingably connected by a pin 16. Also, the lever 9 is the tip of the inner arm 7.
A fixture 17 having a slightly triangular shape is fixed at a position close to, and a flat interlocking bar 18 is interposed between the fixture 17 and the slider 13.
Then, the inner cylinder 7 is slidably moved in the longitudinal direction of the outer arm 5 by expanding and contracting a hydraulic cylinder (not shown in FIG. 6) arranged inside the inner arm 7.

[0003]

The arm in the work attachment of the hydraulic excavator is rational in terms of strength and weight unless the base end side of the arm is formed large and tapered toward the tip end side. I can't get anything. The outer arm of the prior art shown in FIG. 6 is formed in a tubular shape having a quadrangular cross section with the same size on the base end side and the tip end side. For this reason, the tip end side of the outer arm becomes large, and therefore the size of the quadrangular cross section of the inner arm is considerably large.
That is, the quadrangular cross section of the inner arm is unnecessarily large and its weight is too large, which makes the front-back balance of the hydraulic excavator unstable. In addition, the interlocking bar 18 is attached to the inner arm 7
Since it is interposed between the fixture 17 on the upper surface of the slider 13 and the front portion of the slider 13, its mounting structure is complicated and it is difficult to assemble the slider 13. The present invention is
It is an object of the present invention to provide a telescopic arm device that can solve the above problems.

[0004]

In the telescopic arm device of the present invention, the base end portion of the outer arm is rotatably connected to the tip end portion of the boom attached to the front portion of the machine body, and the longitudinal direction of the outer arm. Insert the inner arm slidably into
In a telescopic arm device in which the inner arm is extended and contracted by a telescopic cylinder arranged inside the inner arm, the base end side has a box shape, and the outer side is tapered so as to be tapered toward the tip end side. An arm is formed, a rectangular cylindrical guide frame parallel to the lower plate of the outer arm is provided inside the outer arm, an inner arm is slidably provided inside the guide frame, and an inclined upper surface of the outer arm is provided. A guide plate is provided, and a bucket cylinder base end side bracket is attached so as to be slidable in the front-rear direction along the guide plate, and the bucket cylinder base end side bracket and the front part of the inner arm are connected by a connecting rod. Also, a pair of left and right connecting rods are formed, the base end of the connecting rod is pivotally supported on the left and right side surfaces of the bucket cylinder base end bracket, and the tip of the connecting rod is pivotally supported on the front part of the inner arm. It was pivotally supported on the rod end pin of the telescopic hydraulic cylinder. Also, the pressure oil supply / discharge pipe of the telescopic hydraulic cylinder arranged inside the inner arm is passed from the inside of the boom tip to the inside of the outer arm base.

[0005]

In the telescopic arm device of the present invention, the outer arm is formed so as to form a box-like shape in which the side view is tapered from the base end side toward the tip end side, so that the outer arm has sufficient strength and is at a minimum. The weight can be Therefore, the rectangular tubular guide frame provided inside the outer arm can be made small, and the strength and weight of the inner arm inserted into the guide frame can be reasonably satisfactory. That is, since the weights of the outer arm and the inner arm can be minimized, the balance of the hydraulic excavator can be made stable and energy can be saved. Also, a pair of left and right connecting rods are formed, the base end of the connecting rod is pivotally supported on the left and right side surfaces of the bucket cylinder base end bracket, and the tip of the connecting rod is pivotally supported on the front part of the inner arm. Since it is pivotally supported by the rod end pin of the telescopic hydraulic cylinder, the connecting rod mounting structure can be made simple and strong, and the bucket cylinder proximal end bracket and the inner arm can be easily assembled. it can. Also, the pressure oil supply / discharge pipe of the telescopic hydraulic cylinder arranged inside the inner arm is made to pass from the inside of the boom tip part to the inside of the outer arm base end part. Not exposed. Therefore, the hydraulic piping of the telescopic arm device can be made neat in appearance.

[0006]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a side view of a side digging attachment 20 having a telescopic arm device 19 of the present invention. In the figure, 21 is a rear boom, 22L, 22R
Is a pair of left and right front booms, 23 is an upper boom, 2
4 is an outer arm of the telescopic arm device 19, 25 is an inner arm, 26 is a telescopic hydraulic cylinder, 27 is a bucket cylinder proximal end bracket, 28 is a pair of left and right connecting rods, 29 is a bucket, 30 is a boom cylinder, and 31 is An offset cylinder, 32 is an arm cylinder, 33 is a bucket cylinder, and 34 is a hydraulic pipe leading from the vehicle body (not shown) side to the telescopic hydraulic cylinder 26. FIG. 2 is a plan view of an essential part viewed from A of FIG.

FIG. 3 is a side view of essential parts when the telescopic arm device 19 is in an extended state. In the figure,
Reference numeral 35 denotes a sliding base portion of the bucket cylinder base end side bracket 27, 36 denotes a pin protruding left and right on a side surface portion of the sliding base portion 35, and 37 denotes a rod tip portion of the telescopic hydraulic cylinder 26 in front of the inner arm 25. Rod tip pin pivotally attached to the
Reference numeral 38 is a pin that pivotally mounts the telescopic hydraulic cylinder 26 to the rear portion of the outer arm 24. FIG. 4 is a sectional view taken along line BB of FIG. In the figure, 39 is a guide plate formed on the upper surface of the outer arm 24, 40 is a slide pad that is attached to the inner surface of the sliding base 35 for making smooth sliding contact with the guide plate 39, and 41 is the outer arm 24. A slide pad that is affixed to the inner surface of the body for making smooth sliding contact with the inner arm 25,
42 is a lower surface plate of the outer arm 24, 43 is a side surface plate, 44 is a guide upper plate, and 45 is a guide frame formed by the lower surface plate 42, the side surface plate 43, the upper guide plate 44, and the slide pad 41.

Next, the construction and operation of the telescopic arm device 19 of the present invention will be described with reference to FIGS. In the present invention, the outer arm 24 is formed so that the base end side is box-shaped and has a box shape that is tapered in a side view toward the tip end side. Inside the outer arm 24, the outer arm 24 is parallel to the lower plate 42 of the outer arm 24. A rectangular cylindrical guide frame 45 (shown in FIG. 4) is provided, the inner arm 25 is provided inside the guide frame 45 so as to be slidable by a telescopic hydraulic cylinder 26, and the outer arm 24 is provided with a guide on an inclined upper surface portion. A plate 39 is provided, a sliding base portion 35 of the bucket cylinder base end side bracket 27 is attached so as to be slidable in the front-back direction along the guide plate 39, and pins 36 fixed to the left and right side surface portions of the sliding base portion 35 are mounted. And a rod tip pin 37 (shown in FIG. 3) pivotally attached to the front portion of the inner arm 25 are connected by a connecting rod 28. As described above, the outer arm 24 is formed so as to have a box shape whose side view is tapered from the base end side toward the tip end side. Therefore, the outer arm 24 has sufficient strength and has a minimum weight. be able to. Therefore, the rectangular cylindrical guide frame 45 (shown in FIGS. 4 and 3) provided inside the outer arm 24 is made small, and the strength and weight of the inner arm 25 inserted into the guide frame 45 are reasonably satisfied. Can be something. That is, since the weights of the outer arm 24 and the inner arm 25 can be minimized, the balance of the hydraulic excavator can be made stable and energy can be saved.

Further, in the present invention, the base end portion of the connecting rod 28 is pivotally supported by the pins 36 fixed to the left and right side portions of the slide base portion 35 of the bucket cylinder base end side bracket 27, and the tip end portion of the connecting rod 28 is fixed. Since the rod tip pin 37 of the telescopic hydraulic cylinder 26 pivotally attached to the front portion of the inner arm 25 is pivotally supported, the connecting rod 28 can be easily and strongly attached to the bucket cylinder proximal end bracket. It is possible to easily assemble the 27 and the inner arm 25. Also the inner arm 25
The hydraulic pipe 34 (shown in FIG. 1 and FIG. 3) for supplying and discharging the pressure oil of the telescopic hydraulic cylinder 26 disposed inside the outer arm 24 from the inner side of the front booms 22L, 22R and the upper boom 23 to the outer arm 24 base end portion. I tried to pass it inside. As a result, the hydraulic pipe 34 is not exposed to the outside. Therefore, the hydraulic piping of the telescopic arm device 19 can be made neat in appearance.

FIG. 5 is a partially cutaway side view of the hydraulic excavator with the telescopic arm device 19 of the present invention mounted on the boom 46 of another embodiment. A boom 46 shown in FIG. 5 is a single V-shape when viewed from the side, and is a boom of a work attachment for a so-called standard backhoe hydraulic excavator.

[0011]

In one embodiment of the prior art in which the inner arm is slidably inserted inside the outer arm, in the telescopic arm device, the base end side and the tip end side of the outer arm are formed in a tubular shape having a rectangular cross section. Has been formed. For this reason, the tip end side of the outer arm becomes large, and therefore the size of the quadrangular cross section of the inner arm is considerably large. That is, the quadrangular cross section of the inner arm is unnecessarily large and its weight is too large, which makes the front-back balance of the hydraulic excavator unstable. In addition, the mounting structure of the interlocking bar for interlocking the bucket cylinder base side bracket is complicated,
Moreover, the assembly was difficult. However, in the telescopic arm device of the present invention, the outer arm is formed so as to form a box-like shape in which the side view is tapered from the base end side toward the tip end side, so that the outer arm has sufficient strength and a minimum weight. Can be Therefore, the rectangular tubular guide frame provided inside the outer arm can be made small, and the strength and weight of the inner arm inserted into the guide frame can be reasonably satisfactory. That is, since the weights of the outer arm and the inner arm can be minimized, the balance of the hydraulic excavator can be made stable and energy can be saved. Also, a pair of left and right connecting rods are formed, the base end of the connecting rod is pivotally supported on the left and right side surfaces of the bucket cylinder base end bracket, and the tip of the connecting rod is pivotally supported on the front part of the inner arm. Since it is pivotally supported by the rod end pin of the telescopic hydraulic cylinder, the connecting rod mounting structure is simple and strong, and the bucket cylinder proximal end bracket and inner arm can be easily assembled. it can. Also, the pressure oil supply / discharge pipe of the telescopic hydraulic cylinder arranged inside the inner arm is made to pass from the inside of the boom tip part to the inside of the outer arm base end part. Not exposed. Therefore, the hydraulic piping of the telescopic arm device can be made neat in appearance. Therefore, in the telescopic arm device of the present invention, the weight of the device can be reduced and the device can be made compact, and the appearance can be improved.

[Brief description of drawings]

FIG. 1 is a side view of a side digging attachment equipped with a telescopic arm device of the present invention.

FIG. 2 is a plan view of an essential part seen from A in FIG.

FIG. 3 is a side view of essential parts when the telescopic arm device in FIG. 1 is in an extended state.

FIG. 4 is a sectional view taken along line BB of FIG.

FIG. 5 is a partially cutaway side view of the hydraulic excavator in a state where the telescopic arm device of the present invention is mounted on the boom of another embodiment.

FIG. 6 is a perspective view of an excavator according to an embodiment of the prior art.

[Explanation of symbols]

 5,24 Outer arm 7,25 Inner arm 19 Telescopic arm device 20 Side digging attachment 22L, 22R Front boom 23 Upper boom 26 Telescoping hydraulic cylinder 27 Bucket cylinder base side bracket 28 Connecting rod 34 Hydraulic piping 35 Sliding base 37 Rod end pin 39 Guide plate 42 Bottom plate 45 Guide plate 46 Boom

Claims (4)

[Claims] 1. A base end portion of an outer arm is rotatably connected to a tip end portion of a boom attached to a front portion of a machine body, and an inner arm is slidably inserted in a length direction of the outer arm. In the telescopic arm device in which the inner arm is expanded and contracted by the telescopic cylinder arranged inside the arm, the outer arm is formed in a box shape with the base end side being a box shape and the taper side view toward the tip side. A rectangular cylindrical guide frame parallel to the lower plate of the outer arm is provided inside the outer arm, the inner arm is slidably provided inside the guide frame, and the guide plate is provided on the inclined upper surface of the outer arm. Is installed and a bucket cylinder base end side bracket is attached so that it can slide back and forth along the guide plate, and the bucket cylinder base end side bracket and the front part of the inner arm are connected. Telescopic arm system for a construction machine, characterized in that linked with Guroddo. 2. The telescopic arm device for a construction machine according to claim 1, wherein a pair of left and right connecting rods are formed, and a base end portion of the connecting rods is provided on left and right side surface portions of a bucket cylinder base end side bracket. A telescopic arm device for a construction machine, wherein each of the telescopic arm devices is pivotally supported, and the tip end of the connecting rod is pivotally supported on each of the left and right side surfaces on the front side of the inner arm. 3. The telescopic arm device for a construction machine according to claim 2, wherein the tip of the connecting rod is pivoted to a rod tip pin of a hydraulic cylinder for telescoping which is pivotally supported on the front of the inner arm. A telescopic arm device for construction machinery characterized by being supported. 4. A telescopic arm device for a construction machine according to claim 1, wherein a pressure oil supply / discharge pipe of a telescopic hydraulic cylinder arranged inside an inner arm is arranged from an inside of a boom tip end to an outside arm base. A telescopic arm device for a construction machine, characterized in that it is passed through the inside of the end.