JPH045341A - Boom of small shovel - Google Patents

Abstract

PURPOSE:To reduce weight of a boom and further the cost of manufacture by forming both side face plates of the boom of a steel plate with a U-shaped section, making the plates opposite to each other at a space connecting them fixedly through a base end boss and a point end bracket of the boom. CONSTITUTION:A pair of right and left side face plates 27R, 27L of a boom in a work attachment 17 are formed out of a steel plate whose sections in the lengthwise and the right-angular direction are formed in a C shape. Both the side face plates 27R, 27L are opposed, so that the side ends of upper and lower cross plate parts 29, 29', 30, 30' are placed respectively at spacers from each other, and fixedly connected through a base end boss 20 and a point end bracket 22 of the boom 16. Tightening metal fixtures of pipes 19 are arranged in an interior side of the boom 16 by arranging the pipes 19 for the work attachment through the interior of the boom 16. In this way, necessity for upper and lower face plates over a total length of the boom 16 is eliminated, and further external appearance can be orderly arranged.

Description

[Detailed description of the invention] Industrial applications This invention is mainly used for the boom of small excavators.

Regarding the structure of the arm.

BACKGROUND OF THE INVENTION FIG. 8 is a perspective view of a conventional work attachment 1 mounted on the front part of a small excavator (not shown). In the figure, 2 is the boom of work attachment 1;
3 is an arm, 4 is a packet, 5 is an arm cylinder, 6 is a packet cylinder, 7 is a boom cylinder, 8 is a hydraulic pipe (when a special work machine is attached to the work attachment, a pneumatic pipe may be installed) It is. FIG. 9 is a cross-sectional view of the boom 2 taken along the line AA in FIG. 8. In the figure, 9L and 9R are the left and right side plates of the boom 2;
10 is an upper surface plate, 11 is a lower surface plate, 12 is a fastening fitting for the pipe 8, 13 is a plate with a slot for the fastening fitting 12, 14 is a clamp metal fitting, and 15 is a tightening bolt.

Next, a prior art boom 2 will be described with reference to FIGS. 8 and 9. The boom 2 is formed into a cylindrical body that has a rectangular shape when viewed from the side and is long in the front and back direction.The base end boss of the boom 2 (shown in Fig. 8) is connected to the front part of the small excavator, and the end bracket opening is connected to the front end of the boom 2. Arm 3 is connected. The structure of the boom 2 is integrally surrounded and fixed by a pair of left and right side plates 9L, 9R1, an upper plate 10, and a lower plate 11. Further, a work attachment piping 8 is arranged on the outer peripheral surface side of the boom 2.

Problems to be Solved by the Invention The boom of the prior art is formed into an integral cylindrical shape with a pair of left and right side plates and a top plate and a bottom plate that span the entire length of the boom, so the boom is heavy and manufacturing costs are low. It was expensive. Further, since a large number of work attachment pipings are arranged on the outer peripheral surface of the boom, it is not only unsightly, but also a part of the pipings may come into contact with other external obstacles, causing damage.

It is an object of the present invention to solve the above-mentioned problems and provide a boom for a small excavator that is light in weight, inexpensive to manufacture, and in which work attachment piping can be arranged inside the boom.

Means for Solving the Problems The means of the present invention taken to solve the above problems are as follows: (1) A. The integral left and right side plates of the boom have a cross-sectional shape of It is formed of a steel plate, and (b) the side ends of the upper and lower horizontal plate portions of the pair of side plates are opposed to each other with a space between them, and the pair of side plates are connected via the base end boss of the boom and the tip bracket. Fixed and configured.

(2) B. In the boom of a small excavator as set forth in claim 1, B1 the work attachment piping is arranged to pass through the inside of the boom, and a tightening fitting for the piping is arranged on the inside of the boom. .

1) A. The pair of left and right side plates of the boom are made of steel plates whose cross-sectional shape in the direction perpendicular to the longitudinal direction is shaped like a square. The face plate and bottom plate can be made unnecessary. Further, since press bending is performed when forming the side plate into a mouth shape, welding work is reduced and the manufacturing cost of the boom can be reduced.

(b) Since the side ends of the upper and lower horizontal plate portions of the pair of side plates are opposed to each other with a distance between them, the weight of the boom can be reduced.

(2) Since the piping for the 5 work attachment can be placed so as to pass through the inside of the boom, it not only improves the appearance of the boom, but also prevents accidents where the piping comes into contact with other obstacles and is damaged. be done.

Embodiments Hereinafter, embodiments of the present invention will be described in detail based on the drawings. FIG. 1 is a side view of a work attachment 17 equipped with a boom 16 according to the present invention. In the figure,
Components that use the same components as those in the prior art are given the same reference numerals. 18 is an arm, and 19 is a work attachment piping.

FIG. 2 is a side view of the boom 16 of the present invention.

In the figure, 20 is the base end boss of the boom 16, 21 is the base end reinforcement plate, 22 is the tip bracket, 23 is the top reinforcement plate,
24 is a lower surface reinforcing plate, 25 is an arm cylinder mounting bracket, and 26 is a boom cylinder mounting bracket.

FIG. 3 is a plan view seen from BB in FIG. 2. In the figure, 27L27R are a pair of left and right side plates, and 28 is a crossbeam portion of the tip bracket 22. FIG. 4 is a perspective view showing left and right side plates 27L and 27R of the boom 16.

Since the boom 16 has a dogleg shape in side view, the left side plate 27t has a front plate C and a rear plate 2, and the right side plate 27R has a front plate E and a rear plate during manufacturing. For this reason, I try to connect them. Figure 5 shows the second
It is a CC sectional view of the figure. In the figure, 29.29' are the upper horizontal plate parts of the side plates 27L and 27R, respectively, and 30.3
0' is the lower horizontal plate portion of the side plates 27L and 27R, respectively. FIG. 6 is a sectional view taken along line I)-D in FIG. 2. In the figure, 12° is the clamping fitting for the piping 19, 13° is the plate with a tapped hole for the clamping fitting 12', 14' is the clamping fitting, 1
5' is a tightening bolt. FIG. 7 is a sectional view taken along line E-E in FIG. 1.

Next, the configuration of the boom 16 according to the present invention will be described with reference to FIGS. 1 to 7. Pair of left and right side plates 27L, 27
R is formed of a steel plate whose cross-sectional shape in the direction perpendicular to the longitudinal direction is a single character, and the side ends of the upper horizontal plate portions 29 and 29° of the pair of side plates 27L and 27R, respectively (see Fig. 5)
and the side edges C, and the respective side edges and side edges N of the lower horizontal plate portion 30 and 30' are opposed to each other with a distance L (the dimension of the distance may be set to L' as shown in FIG. 6). The pair of side plates 27L and 27R are connected and fixed via the proximal end boss 20 and the distal end bracket 22. In addition, in the boom 16, the work attachment piping 19 is arranged so as to pass through the inside of the boom 16, and the boom 1
A tightening fitting 12' for the pipe 19 was disposed inside the pipe 6.

Next, the functions of the boom 16 according to the present invention will be described. A pair of left and right side plates 27L of the boom (16),
27R is formed from a steel plate whose cross-sectional shape in the longitudinal direction and the perpendicular direction is 1-shaped, so that the boom 2 (
The upper surface plate 10 and the lower surface plate 11 (see FIG. 9) which cover the upper and lower surfaces over the entire length of the device (see FIG. 8) can be made unnecessary. Further, since press bending is performed when forming the side plates 27L and 27R into a single shape during manufacture, welding work is reduced and the manufacturing cost of the boom can be reduced. Note that when manufacturing the side plates 27L, 27, standard channel steel having a mouth-shaped cross section may be used. Further, the side ends of the upper and lower horizontal plate portions of the pair of side plates 27L and 27R are spaced apart from each other (with a predetermined dimension, L'
etc.), the weight of the boom can be reduced. In addition, the left and right side plates 27L,
Since the above-mentioned spacing of 27° exists between the upper and lower horizontal plates, the work attachment piping 19 can be easily passed through the inside of the boom and fixed with the tightening fittings 12'' provided inside the boom. This not only improves the appearance of the boom 16, but also prevents the piping 19 from coming into contact with other obstacles and being damaged.

Note that the structure of the boom 16 according to the present invention can also be applied to the arm 18 in FIG.

Effects of the Invention In the boom according to the present invention, the pair of left and right side plates of the boom are formed of a steel plate whose cross-sectional shape in the direction perpendicular to the longitudinal direction is a single letter, and the upper and lower horizontal plate portions of the pair of side plates are The side ends were spaced apart from each other and fixed by a proximal end boss and a distal end bracket. This eliminates the need for the upper and lower plates that cover the upper and lower surfaces over the entire length of the boom, as in the prior art, so the weight of the boom can be reduced. In addition, since press bending is performed when forming the side plate into a single shape, the number of welding processes is reduced and the manufacturing cost of the boom can be reduced.

Further, since there is a gap between the upper and lower horizontal plate portions of the left and right side plates, the work attachment piping can be easily passed through the inside of the boom and fixed with the fastening fittings provided inside the boom. Therefore, it is possible not only to improve the appearance of the boom, but also to prevent the piping from coming into contact with other obstacles and being damaged.

[Brief explanation of drawings]

Fig. 1 is a side view of a work attachment equipped with a boom according to the present invention, Fig. 2 is a side view of the boom of this invention, Fig. 3 is a plan view taken from B-B in Fig. 2, and Fig. 4. 5 is a perspective view showing the side plate of the boom of the present invention, FIG. 5 is a sectional view taken along line CC in FIG. 2, FIG.
The drawings are a cross-sectional view taken along the line E--E in FIG. 1, FIG. 8 is a perspective view of the prior art work attachment, and FIG. 9 is a cross-sectional view taken along the line A-A of the prior art boom in FIG. 8. 1, 17----------Work attachment 2.16 Boom 3.18 Arm 8, 19----------Work attachment piping 9L, 9R, 27L, 27R----
--- One side plate 12.12' --- One tightening metal fitting 20 ------------ One base end boss 22 --- −−−−−−−−−−−−1−
----- Tip bracket 29.29' Upper horizontal plate part 30°30' Lower horizontal plate part Patent applicant Yuya Heavy Industries, Ltd.

Claims (2)

[Claims] (1) In a work attachment attached to the front part of a small excavator, the pair of left and right side plates of the boom are formed of steel plates with a cross-sectional shape in the direction perpendicular to the longitudinal direction, and the upper and lower sides of the pair of side plates are A boom for a small excavator, characterized in that the side ends of the horizontal plate portions face each other at intervals, and the pair of side plates are connected and fixed via a proximal end boss and a tip bracket of the boom. (2) In the boom of a small excavator according to claim 1, a work attachment piping is arranged to pass through the inside of the boom, and a tightening fitting for the piping is arranged inside the boom. boom of a small excavator.