JP2003176551A - Tank structure for construction machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simplify the installation structure of a fuel tank and an operating oil tank of a construction machine to facilitate installation and to prevent an installation space from becoming large while improving appearance, and to secure a sufficient air space for the operating oil tank while preventing the air suction of a hydraulic pump and further preventing the operating oil tank from becoming large. <P>SOLUTION: The fuel tank 20 and the operating oil tank 22 are formed as an integral tank 16 partitioned by a partition wall 18. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tank structure of a construction machine, and more particularly to a structure of a fuel tank and a hydraulic oil tank of the construction machine.

[0002]

2. Description of the Related Art FIG. 1 shows a hydraulic excavator, which is a typical example of a construction machine, equipped with an integrated tank of a fuel tank and a hydraulic oil tank constructed according to the present invention. The mounting positions of the tanks are also substantially the same. The prior art will be described with reference to FIG. 5 together with FIG.

The hydraulic excavator 2 is configured as shown in FIG. 5, and is a hydraulic oil containing hydraulic oil for operating a fuel tank 30 for containing fuel of an engine as a power source and a hydraulic actuator for driving a working device. A tank 32 is provided. The fuel tank 30 and the hydraulic oil tank 32 are
Each of them is separately manufactured into a substantially rectangular parallelepiped, and is arranged and mounted on the revolving structure frame 10 of the upper revolving structure 6 of the hydraulic excavator 2.

[0004]

The above-described conventional tank structure for a construction machine has the following problems to be solved.

(1) Installation structure is complicated: Since the fuel tank 30 and the hydraulic oil tank 32 are formed separately, the revolving structure frame 10 has four corners at the bottom of each rectangular shape (of the fuel tank 30). Each of Y1 and Y1 at two points and the hydraulic oil tank 32 at Y2 and Y2 at two points) are attached by bolts or the like. Therefore, there are many attachment points, the attachment parts, the frame structure, etc. are complicated, the work time for attachment is increased, and the manufacturing cost is increased.

(2) Large installation space: The fuel tank 30 and the hydraulic oil tank 32 are mounted with a gap X provided therebetween so as not to interfere with each other. Therefore, the installation space becomes larger by the amount of this gap X. This gap X is not preferable especially in a small turning hydraulic excavator in which it is desired that the size of the machine body is small.

(3) Poor appearance: The clearance X makes the appearance of the hydraulic excavator 2 unsatisfactory by making the appearance of the hydraulic excavator 2 uncontinuous.
In order to improve the appearance, it is necessary to cover the fuel tank 30 and the hydraulic oil tank 32 with covers of separate members, so the size of the machine body is increased and the manufacturing cost is increased.

(4) Larger hydraulic oil tank: The hydraulic oil tank 32 is a fuel tank 3 in which fuel is consumed and replenished.
Unlike 0, it is filled with a specified amount of hydraulic oil and has a closed structure to prevent dust and the like from entering. Then, the height of the oil level L of the hydraulic oil changes due to the operation of the hydraulic actuator. For example, when the hydraulic cylinder is extended, the oil level L
Falls and rises when shortened. Since the air space S, which is an upper air reservoir in the hydraulic oil tank 32, is compressed or expanded due to the fluctuation of the oil level L and the change of the oil temperature, the internal pressure of the hydraulic oil tank 32 fluctuates. Therefore, the hydraulic oil tank 32
Are formed so as to make the air space S as large as possible so as to reduce this pressure fluctuation.

On the other hand, on the bottom surface of the hydraulic oil tank 32, the hydraulic oil suction port 17 of the hydraulic pump is attached to the suction strainer 24.
Has been installed. Since construction machines often operate on sloping terrain or uneven terrain, the suction strainer 24 and the hydraulic oil suction port can be used even if the machine body tilts with the oil level L lowered as shown in FIG. In order to prevent 17 from flowing into the air space S in the tank and sucking air by the hydraulic pump, the height of the oil surface L of the hydraulic oil tank 32 is set to the suction strainer 24 and the hydraulic oil suction port 1.
It is secured at the top with a margin with 7.

Therefore, the hydraulic oil tank 32 has the air space S as large as possible and the suction strainer 2
4 and the hydraulic oil suction port 17 are taken into consideration to increase the amount of hydraulic oil as much as possible. And the installation area also increases accordingly. If the height of the hydraulic oil tank 32 is increased so that the installation area does not become large, it is necessary to give strength to the tank correspondingly, and it is also necessary to make the tank mounting portion stronger.

The present invention has been made in view of the above facts, and its technical problem is to simplify the installation structure of the fuel tank and hydraulic oil tank of the construction machine, to facilitate the installation, and to increase the installation space. To improve the appearance, secure a sufficient air space for the hydraulic oil tank, prevent air suction of the hydraulic pump, and prevent the hydraulic oil tank from becoming large.
It is to provide a tank structure for a construction machine.

[0012]

In the present invention, as a tank structure of a construction machine for solving the above technical problem, a fuel tank and a hydraulic oil tank of the construction machine are formed in an integrated tank partitioned by a partition wall. A tank structure for a construction machine is provided.

The fuel tank and the hydraulic oil tank are integrated to simplify the installation structure, facilitate the installation, prevent the installation space from increasing, and eliminate the gap between the two to improve the appearance. In addition, by appropriately arranging the partition wall between the fuel tank and the hydraulic oil tank, a sufficient upper air space of the hydraulic oil tank is secured, and even if the oil level is tilted, air suction to the hydraulic pump is prevented, and Prevent the hydraulic oil tank from becoming large.

In a preferred embodiment, the partition wall is erected on the bottom surface of the integrated tank. The upper side of the internal space of the hydraulic oil tank is formed larger than the bottom side.
Further, the partition wall is formed by inclining a flat plate.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a tank structure for a construction machine constructed according to the present invention will be described in more detail with reference to the accompanying drawings illustrating a preferred embodiment of a hydraulic excavator which is a typical construction machine. explain.

Referring to FIG. 1, reference numeral 2 is used as a whole.
The hydraulic excavator indicated by is the undercarriage 4 and the undercarriage 4
Upper revolving structure 6 mounted on the upper part so that it can swing horizontally
And a working device 8 attached to the front part of the upper revolving structure 6 so as to be vertically swingable. The upper revolving structure 6 has a driver's cab 12 and a driver's cab 12 at the left front part of the revolving structure frame 10. An integrated tank 16 provided with an engine compartment 14 on the rear side thereof and in which a fuel tank and a hydraulic oil tank according to the present invention are integrated.
Is mounted on the revolving structure frame 10 on the right side.

Referring to FIGS. 2 and 3 together with FIG. 1, the integrated tank 16 is formed in a substantially rectangular parallelepiped extending along the right side edge of the revolving structure frame 10 in the front-rear direction of the hydraulic excavator 2. The integrated tank 16 is partitioned into a front fuel tank 20 and a rear hydraulic oil tank 22 by a partition wall 18 provided upright on the bottom surface 16a, and formed by welding various steel members such as steel plates to each other. Has been done.

The partition wall 18 is formed of a substantially rectangular flat plate, and is attached at an angle θ with respect to the bottom surface 16a, for example, 70 °, with its upper portion tilted toward the fuel tank 20 side. Therefore, the upper side of the internal space of the hydraulic oil tank 24 is formed larger than the bottom side. The position and inclination of the partition wall 18 in the front-rear direction will be described in further detail later.

At a portion of the bottom surface 16a on the hydraulic oil tank 22 side, a hydraulic oil suction port 1 penetrating the bottom surface 16a is formed in the central portion thereof.
7 is formed, and a suction strainer 24 is attached to the inside of the tank of the hydraulic oil suction port 17. The hydraulic oil suction port 17 and the suction strainer 24 may be known ones that have been conventionally used. The hydraulic oil suction port 17 is connected to a hydraulic pump.

The fuel tank 20 is formed so as to be able to communicate with the outside air via a ventilation means (not shown) such as a breather. The hydraulic oil tank 22 is formed in a sealed structure. The fuel tank 20 is provided with a fuel injection port, a fuel supply port, etc., and the hydraulic oil tank 22 is provided with a hydraulic oil injection port, a return oil inflow port, etc. (These are not directly related to the invention of the present application. Therefore, the illustration is omitted to avoid complication of the drawing).

The position and inclination of the partition wall 18 in the integrated tank 16 in the front-back direction (left-right direction in FIG. 2) will be described. In the partition wall 18, the air space S above the oil surface L of the hydraulic oil filled in the hydraulic oil tank 22 is
2 (FIG. 5) is substantially equal to the air space S, and the oil level L indicated by the solid line at the lowermost height when the hydraulic cylinder or the like is operated is inclined by the tilt of the machine body of the hydraulic excavator 2. In the state shown by the dotted line, the conventional hydraulic oil tank 32
In order to prevent the hydraulic oil suction port 17 and the suction strainer 24 from coming out of the air space S with a smaller amount of oil than (FIG. 5), the upper side is moved closer to the fuel tank 20 side, and the lower side is reversed to the fuel tank 2
It is inclined from the 0 side at an angle θ with respect to the bottom surface 16a.

The integral tank 16 is attached to the revolving structure frame 10 at four corners (indicated by Z) at the front, rear, left and right of the rectangular bottom surface 16a by bolts or the like. This mounting structure may be similar to that of the conventional fuel tank 30 or the hydraulic oil tank 32, and therefore detailed illustration thereof is omitted.

The operation of the tank structure of the construction machine as described above will be described.

(1) Simplification of installation structure and easy installation:
The integrated tank 16 in which the fuel tank 20 and the hydraulic oil tank 22 are integrated is attached to the revolving structure frame 10 at four points (Z) on the bottom surface 16a. Therefore, the number of attachment points is reduced by half, the installation structure is simplified, and the installation work is facilitated.

(2) Space saving and improved appearance: Since the fuel tank 20 and the hydraulic oil tank 22 are integrated and attached to the fuselage with the integrated tank 16, it is conventionally provided between the fuel tank 30 and the hydraulic oil tank 32. The gap X disappeared. Therefore, it is possible to save the installation space and improve the appearance.

(3) Ensuring an air space, preventing size increase, preventing air suction, and reducing hydraulic oil: The partition 18 for partitioning the fuel tank 20 and the hydraulic oil tank 22 has a large space above the hydraulic oil tank 22 and a large space above the hydraulic oil tank 22. By arranging the space so as to be small, the air space S of the hydraulic oil tank 22 can be defined sufficiently large with respect to the hydraulic oil amount, and a high oil level L can be secured with a small hydraulic oil amount. Therefore, the air space S in the hydraulic oil tank 22 is secured, the tank is prevented from being upsized, air is not sucked into the hydraulic pump, and the amount of hydraulic oil is reduced, so that the hydraulic oil can be saved.

(4) Increasing fuel amount: The partition wall 18 defines a small space on the lower side of the hydraulic oil tank 22, and the space on the lower side of the fuel tank 20 is increased accordingly. Therefore, the amount of fuel tank 20 can be increased.

(5) Increased tank mounting strength: integrated tank 1
In No. 6, the tank bottom area is larger than the conventional one with respect to the height. Therefore, the mounting strength is improved, and the load on the tank mounting bolts is reduced.

(6) Cost reduction: The fuel tank and the hydraulic oil tank are integrated to reduce the number of tanks themselves. Further, both can be partitioned by a single flat partition wall.
Also, the number of tank mounting bolts and the number of mounting portions of the fuselage are reduced. Therefore, the manufacturing cost can be reduced.

The present invention has been described in detail above based on the embodiments. However, the present invention is not limited to the above embodiments, and various variations or modifications can be made within the scope of the present invention. It is a thing.

For example, in the present embodiment, the partition wall 18 for partitioning the fuel tank 20 and the hydraulic oil tank 22 is formed of a flat plate. However, like the partition wall 26 shown in FIG. 4, a single plate is bent. Alternatively, a plurality of plates may be appropriately joined to each other so that the space on the upper side of the hydraulic oil tank 22 is larger than the space on the bottom side. That is, the lower wall 26a that extends vertically upward from the bottom surface 16a and the horizontal wall 2 that has its tip extending horizontally toward the fuel tank 20 side.
6b and an upper wall 26c extending vertically upward from its tip
You may form by.

[0032]

According to the tank structure of the construction machine constructed according to the present invention, the installation structure of the fuel tank and the hydraulic oil tank of the construction machine is simplified, the installation is facilitated, and the installation space is increased. It is possible to prevent and improve the appearance, secure a sufficient air space in the hydraulic oil tank, prevent air suction of the hydraulic pump, and prevent the hydraulic oil tank from becoming large.

[Brief description of drawings]

FIG. 1 is a perspective view of a hydraulic excavator that is a typical example of a construction machine including a tank structure for a construction machine configured according to the present invention.

FIG. 2 is a structural explanatory view of an integrated tank shown in a sectional view as seen in the direction of arrow A in FIG.

FIG. 3 is a structural explanatory view showing the integrated tank shown in FIG. 2 in a perspective state.

FIG. 4 is a structural explanatory view showing another form of the partition wall.

5 is a structural explanatory view showing a cross section of a conventional tank as viewed in the direction of arrow A in FIG.

[Explanation of symbols]

2: Hydraulic excavator (construction machinery) 16: Integrated tank 16a: bottom 18: Partition wall 20: Fuel tank 22: Hydraulic oil tank 26: Partition wall 30: Fuel tank 32: Hydraulic oil tank

Claims (4)

[Claims] 1. A tank structure for a construction machine, wherein the fuel tank and the hydraulic oil tank of the construction machine are formed as an integral tank partitioned by a partition wall. 2. The tank structure for a construction machine according to claim 1, wherein the partition wall is erected on the bottom surface of the integrated tank. 3. The upper side of the internal space of the hydraulic oil tank,
The tank structure for a construction machine according to claim 1, wherein the tank structure is formed to be large with respect to the bottom side. 4. The tank structure for a construction machine according to claim 1, wherein the partition wall is formed by inclining a flat plate.