JP2003136979A - Fuel tank structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel tank structure capable of accurately indicating volume of oil in a tank even under a condition that a tank is divided and is communicated each other at positions having height difference. SOLUTION: In a fuel tank capable of taking fuel in and out each other between two divided tanks via a communication pipe, a sensor is attached on each tank to divide a fuel level detecting position in a vertical direction and electric circuits of the both sensors are connected in series. Consequently, whole fuel quantity in the tank can be read out at the time according to change of fuel quantity.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel tank structure provided on an upper swing body of a hydraulic shovel, and more particularly to a fuel tank structure having a large capacity. 2. Description of the Related Art Conventionally, in a hydraulic excavator, for example, as shown in a plan view of FIG. 7 and a perspective view of FIG.
2. A hydraulic device 23 such as an operation valve is provided below the operator seat in the cab 22, a fuel tank 24 and a hydraulic oil tank 25 are provided on a right side, a working machine (not shown) is provided in a central portion, and an engine room 26 is provided on a rear side. , A counterweight 27 and the like are arranged, and the engine room 26 has attached devices such as cooling,
A hydraulic pump and the like are installed. R in FIG. 7 indicates the turning radius at the turning center. [0003] However, in the case of the above-mentioned layout, the harmful effects of noise and heat caused by hydraulic devices such as operation valves below the operator seat adversely affect the driver. There is a drawback that repair when a hydraulic device breaks down is troublesome and maintenance is poor. On the other hand, a single fuel tank is arranged in one outer space despite the fact that no noise or heat is generated even during the operation of the vehicle, and therefore no inspection or the like is required at all times. However, the arrangement was limited in capacity because only one space was utilized. When the fuel tank is divided and installed,
In order to know the level of each oil level, a level sensor is attached to one of them. There is no problem if the height of the two tanks is almost the same, but if the height of the two tanks is There is a problem that the reduction of the oil read on the gauge scale is not constant if only one level sensor is used. In view of the foregoing, the present invention provides a fuel tank structure which can accurately display the oil volume in the tank even when the tank is divided and communicated at positions having different heights. It is intended to eliminate the disadvantages of technology. [0006] As a means for solving the above-mentioned problems of the prior art, an oil level in a fuel tank in which oil can enter and leave each other through a communication pipe to a tank divided into two parts is described. A sensor is attached to each tank so as to divide the detection position in the vertical direction, and both sensor electric circuits are connected in series. According to the above construction, since an oil amount detection sensor is provided in each of the divided tanks and the electric circuits are connected in series, the amount of oil in the tank at that time is changed according to the change in the oil amount. You can read the total amount of oil. The present invention will be described below with reference to an embodiment shown in FIGS. The fuel tank according to the present invention is provided with an arc-shaped lower tank 3 on one side along the upper revolving unit 1 in a floor frame 2 of an upper revolving unit 1 such as a hydraulic shovel, and provided on an upper surface of the upper revolving unit 1. A front tank 5 is provided so as to protrude from the lower tank 3 near the lower portion of the operator seat 4, and a rear tank 6 having an appropriate height also protruding from the lower tank 3 is provided at the rear of the operator seat 4. It is composed of those provided. FIGS. 1 to 3 show details of a fuel tank according to the present invention.
And a rear tank 6, which is made of resin and has a free-sized, left-right asymmetric, odd shape. That is, since the lower tank 3 is provided using the space in the floor frame 2 without waste, the left side has an arc shape along the upper swing body 1 and the height is formed substantially constant. I have. The front tank 5 has a substantially square plane from the front central portion of the lower tank 3 to the portion immediately below the operator seat 4, and the rear tank 6 is behind the front tank 5. It is provided so as to stand up from the lower tank 3 at a constant interval from the front tank 5. The rear tank 6 has a predetermined depth, and its front surface is partitioned by the cab 7 at a position facing the rear wall 7a of the cab 7, and is provided on the engine room side. Therefore, the capacity of the fuel tank according to the present invention can be greatly increased as compared with the conventional front tank alone or only the rear tank alone, and as a result, the continuous operation time can be extended. FIG.
Reference numeral 8 denotes a revolving frame for mounting a working machine. As shown in FIGS. 4 and 5, in a fuel tank in which oil can flow in and out of two tanks 9 and 10 through a communication pipe 11, a sensor is provided for each of the tanks. 12 and 13 are mounted, and the electric circuits of both sensors 12 and 13 are connected in series. In addition, even in the case of the tank shown in FIGS.
A similar effect can be obtained by attaching a sensor also to the upper intermediate portion of the above. The sensors 12 and 13 have floats 14 and 14, respectively, in the tanks 9 and 10, and when the oil in the tanks decreases, the sensor 1 detects that the float 13 has descended.
2 and 13 are detected by respective electric resistances R1 and R2. Next, the operation will be described. When the oil level in the upper tank 9 decreases and the oil level decreases, the sensor 1
2, the sensor 13 is activated when the oil in the lower tank 10 decreases and the oil level decreases. Accordingly, as shown in FIG. 6, the resistance values (combined resistance values) of both sensors continuously change from the full state to the empty state, as shown in FIG. 6, and can be linked with the scale of the gauge. This makes it possible to make the scale of the gauge substantially equal to the remaining amount of oil in the tank. As described above, according to the present invention, a front tank is provided below an operator seat provided in a cab of an upper revolving structure such as a hydraulic excavator, and a rear side of the operator seat is provided outside the cab. A rear tank is provided, and an arc-shaped lower tank is provided on one side in the floor frame of the upper revolving structure such as a hydraulic excavator, and an operator seat provided on the upper surface of the upper revolving structure is provided. In the vicinity of the lower portion, a front tank is provided so as to protrude from the lower tank, and a rear tank of an appropriate height is also provided at a rear portion of the operator seat, which also protrudes from the lower tank,
In addition, by providing the front tank inside the cab and the rear tank outside the cab, it is possible to greatly increase the tank capacity as compared with a conventional small-sized hydraulic excavator. Can also be longer. Also, in a fuel tank in which oil can flow into and out of the two divided tanks through a communication pipe, a sensor is attached to each tank and the electric circuit of both sensors is connected in series, so that the electric resistance value and the oil By making the remaining amount proportional, it is possible to make the scale of the gauge substantially equal to the remaining amount of oil in the tank.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view showing one embodiment of a fuel tank structure according to the present invention. FIG. 2 is a side view of FIG. FIG. 3 is a front view of FIG. 1; FIG. 4 is a side view showing one embodiment of a sensor provided in a fuel tank according to the present invention. FIG. 5 is an electric circuit diagram showing a variable resistor of a sensor part of FIG. 4; FIG. 6 is a graph showing the relationship between the electric resistance and the remaining amount of oil according to FIG. 4; FIG. 7 shows a conventional upper revolving unit (including a fuel tank).
It is a top view which shows arrangement | positioning. FIG. 8 shows a conventional upper revolving unit (including a fuel tank).
It is a perspective view which shows arrangement | positioning. [Description of Signs] 1 Upper revolving unit 2 Floor frame 3 Lower tank 4 Operator seat 5 Front tank 6 Rear tank 9, 10 Tank 11 Communication pipe 12, 13 Sensor

Claims (1)

Claims: 1. A fuel tank in which oil is allowed to enter and exit from a tank divided into two via a communication pipe so that an oil level detection position is divided in a vertical direction. A fuel tank structure, wherein a sensor is mounted on the fuel tank and the electric circuits of both sensors are connected in series.