JPH11303139A - Upper structure of construction machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the degree of freedom of the arranged position of an engine in an engine room and maintain sufficient strength while restraining increase of weight and cost by preventing at least either side of right and left a pair of front strength members and rear strength members from being arranged in the same line. SOLUTION: In a machine body frame 10 of upper swinging body, vertical plates as a pair of longitudinal strength members pivotally supporting a boom base part standingly provided on a lower face plate 11 are formed into divided forms of front vertical plates 12 and rear vertical plates 13, and the front vertical plates 12 and the rear vertical plates 13 are fixedly secured through a lateral plate 14. Within corner parts crossing the lateral plate 14 with the front vertical plates 12 and the rear vertical plates 13, against the corner parts nearby an engine loaded on the upper swinging body reinforcing plates 20L, 20R of nearly triangular shape in plane view are respectively fixedly provided in the horizontal direction. Consequently, when the engine is arranged in an engine room on the rear part of the frame 10, the space between the rear vertical plates 13, 13 can be set into optimum pitch so as to meet the size and shape of the engine.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an upper revolving structure of a construction machine such as a small-swing hydraulic excavator having a reduced turning radius at a rear end.

[0002]

2. Description of the Related Art FIG. 8 is a perspective view showing a revolving frame 6 of an upper revolving structure of a small-swing hydraulic excavator according to an embodiment described in Japanese Patent Application Laid-Open No. 9-209401. The revolving frame 6 shown in FIG. 8 is a substantially circular plate-shaped bottom plate 6B, and is located substantially at an intermediate portion in the width direction of the bottom plate 6B and extends in the front-rear direction. (Not shown) and a pair of beams 6A, 6A also serving as a support bracket for rotatably supporting the base end side. On the left side of the bottom plate 6B of the revolving frame 6, fixing portions 6C, 6C,... For fixing the driver's cab on the revolving frame 6 are provided at four places. At the rear side, fixing portions 6D, 6D,... For fixing the engine on the turning frame 6 are provided at four places. Reference numerals 33, 33 denote partitions provided between the operator's cab and the machine room on the bottom plate 6B of the revolving frame 6, and the partitions 33, 33 are beams of the revolving frame 6. 6A, a long metal plate extending in the width direction from the left beam 6A to the left end of the bottom plate 6B of the bottom plate 6B, and the partition plates 33, 33 are fixed to the bottom plate 6B by welding or the like. . The two fixed portions 6C, 6C located at the rear side of the operator's cab among the fixed portions 6C, 6C,.
6D, two fixed portions 6D located on the front side of the engine are fixed to the partition plate 33 by means such as welding.

[0003]

Conventionally, in a small-slewing hydraulic excavator, an upper revolving structure has a substantially circular shape (round shape) in plan view, and a heavy engine or counter is provided at the rear of the upper revolving structure. Weights are mounted. In this case, for example, as shown in FIG. 8, the revolving frame (body frame of the upper revolving unit) 6 is located at a substantially central portion in the width direction of the bottom plate 6B, which is a flat plate formed in a substantially circular plate shape. A pair of beams (strength members) 6A that extend in the front-rear direction and also serve as support brackets for rotatably supporting a base end side of a boom (not shown) of a working device (also referred to as a working attachment). , 6A.

[0004] In the case of a small-swing hydraulic excavator or the like, the space for disposing the equipment in the engine room, which is usually set at the rear of the upper revolving structure, becomes considerably narrow. Further, since the beams 6A, 6A, which are strength members in the front-rear direction, extend in the front-rear direction substantially at the center of the fuselage, it is necessary to prevent interference when the engine is arranged in the engine room. The above freedom was restricted. Also, since the beam is a strength member, a certain thickness (t) and a certain height (hf
~ Hr) is required. Therefore, when the engine is arranged on the beams 6A, 6B, the position of the center of gravity becomes high, adversely affecting the stability and the engine room itself becomes large in the vertical direction. The rear view from the room might be deteriorated.

In order to avoid such a situation, the strength member in the front-rear direction is divided in the middle, and the rear portion from the middle divided portion is located in the engine room, so that the space between the pair of left and right reinforcing members can be freely adjusted. Means for positioning the strength member in accordance with the shape of the mounted engine and the position of the fixed portion. More specifically, it is divided at the part of the partition plate 33 which is a lateral strength member, and the rear end portion of the front strength member among the longitudinal strength members is partitioned by the partition plate 33.
And the front end of the rear strength member of the front-back strength members is welded to the partition plate 33 to make the entire strength member (including the bottom plate 6B) integral.

However, if the longitudinal strength member is divided in the middle, there is a disadvantage in strength. In particular, since the engine room portion supports a heavy object such as an engine at a position distant from the turning center O, vibrations during traveling of a hydraulic shovel or the like cause stress concentration around the connecting portion between the partition plate 33 and the rear strength member, and cracks occur. There is a possibility that a problem such as occurrence of a problem may occur. In order to maintain the strength in the case where the strength is not divided while dividing, the strength of the strength member is increased (if the material is a plate, the thickness (t) is increased) or the thickness of the bottom plate (6B) itself is increased. It is necessary to take measures such as welding or reinforcing a large number of reinforcing members. This involves inconveniences such as an increase in manufacturing cost, a decrease in productivity due to an increase in the number of parts, and an unnecessary increase in machine weight.

[0007]

A construction machine having a lower traveling structure, an upper revolving structure rotatably mounted on the lower traveling structure, and a work attachment provided on the upper revolving structure to be able to undulate. The upper revolving unit is connected to a pair of left and right front strength members that pivotally support the work attachment erected in the upper revolving unit front-rear direction and to the rear end of the vertical plate orthogonal to the pair of vertical plates. An intermediate strength member that is erected and connected, a front end is connected to the horizontal plate, and a pair of left and right rear strength members that are erected in the front-rear direction, the intermediate strength member, and the rear strength member are connected to each other. And a reinforcing member.

[0010] According to this, there is a degree of freedom in the relative spacing between the pair of right and left rear strength members, and a good space for arranging equipment on the upper swing body can be obtained. In addition, since the reinforcing member is provided so as to be connected across the intermediate strength member and the rear strength member, sufficient strength can be obtained without increasing the thickness of the strength member and the bottom plate by adding the necessary minimum parts. Can be.

Further, the reinforcing member is formed of a plate member having a substantially triangular shape in a plan view, while being separately connected to the left and right rear strength members and the intermediate strength member, respectively. According to this, it is possible to adjust the size (area in plan view) of the reinforcing member formed of the plate member having a required thickness according to the required strength. It does not occupy the space in the vertical direction above and does not hinder when arranging various devices.

Alternatively, the reinforcing member is formed of a plate member connected to the pair of right and left rear strength members and the intermediate strength member, and recessed about the center in the left-right direction toward the front in plan view. . According to this, the number of parts can be further reduced as compared with the above-described one.

More specifically, the pair of left and right front strength members support the work attachment, and the rear of the intermediate strength member is set in an engine room in which an engine is disposed. At least one of the pair of left and right front strength members and the pair of left and right rear strength members is not arranged on the same line in the front-rear direction. Thereby, the degree of freedom in the arrangement position of the engine in the engine room is increased, and it is possible to prevent the engine room from being enlarged, and to maintain sufficient strength.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is an overall side view of a small swing hydraulic excavator 1 equipped with an upper swing body according to an embodiment of the present invention. In the drawing, reference numeral 2 denotes a lower traveling body of the excavator 1, 3 denotes an upper revolving body rotatably mounted on the lower traveling body 2, and 4 denotes a cab for an operator's cab mounted on a left front portion of the upper revolving body 3. 5, an engine mounted on the rear part of the upper revolving unit 3, 6 an engine room for storing and arranging the engine 5 and the like,
Reference numeral 7 denotes a counterweight, 8 denotes a work attachment provided on the upper swing body 3 so as to be able to move up and down, and 9 denotes a boom of the work attachment 8. FIG. 2 is a side view of a main portion of the upper swing body 3 in FIG. 1. In the drawing, reference numeral 10 denotes a body frame of the upper revolving unit 3, reference numeral 11 denotes a lower plate serving as a bottom plate of the body frame 10, reference numeral 12 denotes a front strength member constituting the body frame 10, and a boom 9 which is erected on the lower plate 11 and stands. A pair of front and rear longitudinal plates 13 pivotally supporting the base, 13 are a pair of front and rear longitudinal plates which are rear strength members similarly constituting the body frame 10, and 14 is a front vertical plate 12 and a rear vertical plate 13.
, 15a, 15b, 15c, 15d (15b, 15d)
Are not shown in the drawing because they are on the opposite sides of 15a and 15c, respectively).
16b, 16c, 16d (16b, 16d are each 1
6a, 16c, so that they are not shown in the drawing) are mount mounting parts for each engine (5), 17 is a counterweight (7) fastening part, and 12a is a boom (9) base end pivot of the front vertical plate 12. It is a branch.

FIG. 3 is a plan view of a main part of the body frame 10 shown in FIG. In the drawing, reference numeral 18 denotes a front plate fixedly provided (by welding and fixing) between a pair of left and right front vertical plates 12 and 12, reference numeral 19 denotes a swivel joint (not shown) mounting portion, and reference numerals 20L and 20R designate strengths, respectively. A reinforcing plate as a member, 21 is a rear vertical plate rear end side support plate, center 0 is a turning center of the upper turning body 3, and 22 is a turning race, which turns the upper turning body 3 and the lower traveling body 2 through bearings. They are freely connected. FIG. 4 is a diagram viewed from BB in FIG. FIG. 5 shows the body frame 1 shown in FIGS.
FIG. FIG. 6 is an enlarged detailed view of a portion C in FIG.

Next, the upper rotating body 3 according to one embodiment of the present invention.
1 to 6 will be described. In the present embodiment, the body frame 1 of the upper swing body 3 having a substantially circular shape in plan view.
At 0, a pair of longitudinal plates, which are a pair of longitudinal strength members that are erected on the lower surface plate 11 and pivotally support the base of the boom 9, are formed in a divided shape of a front vertical plate 12 and a rear vertical plate 13; Vertical plate 1
2 and the rear vertical plate 13 are fixed to each other via a horizontal plate 14 (by welding), and among the corner portions where the front vertical plate 12 and the rear vertical plate 13 intersect with the horizontal plate 14, the upper portion is formed. Revolving superstructure 1
The reinforcement plates 20L and 20R each having a substantially triangular shape in plan view are provided in the horizontal direction with respect to the corner portions C1 and C2 (shown in FIG. 3) close to the engine 5 (shown in FIG. Was fixed at).

Thus, the interval between the pair of rear vertical plates 13-13 in the front-rear direction (referred to as a pitch PR shown in FIG. 3).
In order to arrange the engine in the engine room at the rear of the body frame 10, the pitch can be set to an optimum pitch according to the size and shape of the engine. Further, a reinforcing plate 2 having a substantially triangular shape in a plan view is provided in parallel with the lower surface plate 11 with respect to the corner portions C1 and C2 close to the engine 5 mounted on the upper rotating body 3.
0L and 20R are provided in the horizontal direction, so that the vertical plate 12 and the horizontal plate 14 can be prevented from falling down, and the lower plate 1
1 can be prevented, and by setting the thickness of the horizontal plate 14, the lower surface plate 11 and the like to the minimum required thickness, increase in weight and cost can be suppressed.

Since the reinforcing plates 20L and 20R are made of a plate material, the reinforcing plates 20L and 20R themselves do not occupy a space in the height direction, so that the reinforcing plates 20L and 20R can be mounted with a high degree of freedom. However, it is more advantageous to arrange at a position as high as possible in terms of strength.

Further, the reinforcing plates 20L and 20R are connected to the engine mount mounting portions 16a and 16a on the side close to the horizontal plate 14.
The lower end surfaces of 16b (portions indicated by reference numerals a and b in FIG. 6) are supported. As a result, the engine mount mounting portions 16a and 16b are attached to the rear vertical plates 1 respectively.
3, 13 and the horizontal plate 14, and the reinforcing plates 20L and 20R can be firmly fixed (welded).
In comparison, the rear vertical plate 13, the horizontal plate 14, and the reinforcing plate 2
The strength and rigidity of 0L and 20R can be secured.

Further, the rear vertical plate 13 has a plate thickness t.
R (shown in FIG. 3) is the thickness tF of the front vertical plate 12.
By setting the size different from that of the upper
The thickness tR of the rear vertical plate 13 is set to the minimum necessary size in accordance with the weight load of the engine 5, the counterweight 7, etc. acting on the rear part of the body frame 10 of
Problems such as large weight increase and cost increase, and uneconomic problems can be avoided.

FIG. 7 is a perspective view of a main part showing a fixed state of a reinforcing plate 20 of another example in the upper swing body 3 of the present embodiment. In the figure, components using the same components as those of the body frame 10 shown in FIG. The reinforcing plate 20 shown in FIG. 7 was formed as a single plate extending over two corners C1-C2 of the corners. That is, when there is no possibility of causing interference with devices such as the engine 5, a single reinforcing plate 20 is provided over two corner portions C1-C2 close to the engine 5. Thereby, the reinforcing plate 20 in the body frame 10 'can be made stronger, and the number of members of the reinforcing plate is reduced, which is advantageous in cost.

[0020]

According to the first aspect of the present invention, there is a degree of freedom in the relative spacing between the pair of left and right rear strength members, and a good space for equipment arrangement on the upper revolving unit can be obtained. It is advantageous when arranging. In addition, since the reinforcing member is provided so as to be connected across the intermediate strength member and the rear strength member, sufficient strength can be obtained without increasing the thickness of the strength member and the bottom plate by adding the necessary minimum parts. Therefore, an increase in weight and cost can be suppressed.

Further, according to the second aspect of the present invention, it is possible to adjust the size (area in plan view) of the reinforcing member formed of a plate member having a required thickness according to the required strength, For this reason, the reinforcing member does not occupy the space in the vertical direction on the upper rotating body, and does not hinder the arrangement of various devices.

According to the third aspect of the present invention, the reinforcing member is connected to the pair of left and right rear strength members and the intermediate strength member, and has a center in the left-right direction centered forward in plan view. And a concave plate member. According to this, the number of parts can be further reduced as compared with the above-described one.

According to the fourth aspect of the present invention, the pair of left and right front strength members supports the work attachment, and the rear of the intermediate strength member is set in an engine room in which an engine is arranged. In addition, at least one of the pair of left and right front strength members and the pair of right and left rear strength members is not arranged on the same line in the front-rear direction. Thereby, the degree of freedom in the arrangement position of the engine in the engine room is increased, and it is possible to prevent the engine room from being enlarged, and to maintain sufficient strength.

[Brief description of the drawings]

FIG. 1 is an overall side view of a small swing hydraulic excavator equipped with an upper swing body according to an embodiment of the present invention.

FIG. 2 is a side view of a main part of the upper revolving structure in FIG. 1;

FIG. 3 is a main part plan view of the body frame in FIG. 2 as viewed from AA.

FIG. 4 is a diagram viewed from BB in FIG. 3;

FIG. 5 is a perspective view of a main part of the body frame shown in FIGS. 2 to 4;

FIG. 6 is an enlarged detailed view of a part C in FIG. 5;

FIG. 7 is a perspective view of a main part showing a fixed state of a reinforcing plate of another example in the upper swing body of the present embodiment.

FIG. 8 is a perspective view showing a revolving frame of an upper revolving body of a small-swing hydraulic excavator according to one embodiment of the prior art.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 (Small swing type) hydraulic excavator 2 Undercarriage 3 Upper revolving body 5 Engine 7 Counterweight 8 Work attachment 9 Boom 10, 10 'Airframe 11 Lower surface plate 12 Front vertical plate 12a Boom base pivot support 13 Rear vertical plate 14 Horizontal plate 16a, 16b, 16c, 16d Engine mount attachment part 20, 20L, 20R Reinforcement plate C1, C2 Corner part 0 Center of rotation

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masato Kobayashi 3-12-4 Gion, Asanami-ku, Hiroshima City, Hiroshima Prefecture Inside Aburaya Heavy Industries, Ltd. No. 12 in Aburaya Heavy Industries, Ltd.

Claims (4)

[Claims] 1. A construction machine comprising: a lower traveling structure; an upper revolving structure rotatably mounted on the lower traveling structure; and a work attachment rotatably provided on the upper revolving structure. A pair of left and right front strength members erected in the front and rear direction of the upper revolving structure, an intermediate strength member orthogonal to the pair of vertical plates, and erected connected to the rear end of the vertical plates, A front end is connected to the horizontal plate, and a pair of left and right rear strength members erected in the front-rear direction, the intermediate strength member, and a reinforcing member connected to the rear strength member are provided. Upper revolving structure of construction equipment. 2. The reinforcing member is connected to each of a pair of left and right rear strength members and the intermediate strength member separately from the left and right sides, and is formed of a plate member having a substantially triangular shape in plan view. The revolving superstructure of a construction machine according to claim 1, wherein 3. The reinforcing member is connected to a pair of left and right rear strength members and the intermediate strength member, and is formed of a plate member that is recessed toward the front in plan view with a center in the left-right direction. The revolving superstructure of a construction machine according to claim 1, wherein: 4. The pair of left and right front strength members supports the work attachment, the rear of the intermediate strength member is set in an engine room in which an engine is disposed, and the pair of left and right front strength members is provided. The upper revolving structure of a construction machine according to claim 1, wherein at least one of the member and the pair of left and right rear strength members is not arranged on the same line in the front-rear direction.