JPS6214023A - Liquid level detector - Google Patents

Abstract

PURPOSE:To enable a liquid surface level to be smoothly detected without being disturbed by a confined space for mounting a liquid level detector thereon or by the wall surface of a tank with projections, if ever, by providing a float and a variable resistor for transducing a change in a liquid level to the change of an electric resistance. CONSTITUTION:The buoyancy of a float 8 is maximum and a slider 5 rotated by the tension of a nylon thread due to the buoyancy minimizes the value of the resistance of a variable resistor 4 when a liquid surface L' is at full level. As the liquid surface L' approaches to a level corresponding to the point E of a fuel meter, the buoyancy of the float 8 is decreased to increase the resistance value of the variable resistor 4 by the slider 5 rotated by the returning force of a biased control spring 7 and, when the liquid surface L' reaches a level corresponding to the point E of the fuel meter, the resistance value becomes maximum. Since the float 8 can float in a shape along the wall surface of the tank due to the flexibility of the float 8 in a direction of its length when it is floating in the liquid and, moreover, the buoyancy changed in accordance with the level of the liquid surface L' is utilized for detecting a liquid level, this liquid level can be detected without being affected by the configuration or the like of the wall surface of the tank.

Description

[Detailed Description of the Invention] <Technical Field of the Invention> The present invention relates to a liquid level detection device attached to a fuel tank of a motorcycle, etc., and in particular, to a float and a liquid level detection device that converts a change in liquid level into a change in electrical resistance. The present invention relates to a liquid level detection device including a variable resistor and a connection body that connects the float to an actuator of the variable resistor.

(Technical background) Fuel tanks of motorcycles are equipped with a liquid level detection device for determining the total liquid level. FIG. 10 shows a float type liquid level detection device (fuel level sensor) b attached to a fuel tank a of a motorcycle. The float type liquid level detection device uses a float C floating on the liquid level.
, a variable resistor (potentiometer) d that converts a change in liquid level caused by the float c into a change in electrical resistance, and a connecting body r that connects the float C to the actuator e of the variable resistor d. It is said to be configured with the following features.

(Prior Art and Problems) Conventionally, in the above-mentioned float type liquid level detection device, a swing arm made of a rigid body ($11!) is generally used as the connection body f that connects the float c to the actuator e of the variable resistor d. As a result, when the float C is displaced due to changes in the liquid level, the trajectory is fixed, and if there is a tank wall near that trajectory, the float C will interfere with the tank wall. It becomes impossible to follow changes in the liquid level, and as a result, the liquid level becomes impossible to measure.

In other words, when the liquid level changes, the float c follows it and is displaced, but in this case, the float C follows an imaginary line on an arcuate trajectory g centered around the rotation axis e of the variable resistor d. Displace as shown in the figure. However, if there is a tank wall surface near the trajectory g during the displacement process, the float C will interfere with the tank wall surface and will not be able to follow the change in the liquid level. If the liquid level reaches the level corresponding to point F (approximately 60% of the full level), it will interfere with the tank wall, making it impossible to measure the liquid level from the level corresponding to point F on the fuel meter to the full level. It becomes possible.

In recent years, the fuel tanks of motorcycles have become increasingly complex in shape, which limits the installation location of the liquid level detection device and tends to require a narrow space. Therefore, in the case of the liquid level detection device of the above-mentioned conventional structure, which employs a swing arm made of a rigid body as the connecting body that connects the float C to the actuator e of the variable resistor d, there are some tanks in which installation is impossible. Further, even if the device can be installed, a problem arises in that the predetermined measurement function cannot be achieved.

(Objective of the Invention) Therefore, an object of the present invention is to provide a liquid level detection device capable of dealing with the above-mentioned circumstances.

(Structure of the Invention) In order to achieve the above object, the present invention includes a float, a variable resistor that converts a change in liquid level into a change in electrical resistance, and a connection that connects the float to an actuator of the variable resistor. A liquid level detection device comprising a body, wherein the float has a flexible structure when suspended in the liquid, and the connecting body is composed of a member whose tension changes according to a change in buoyancy of the float. A control spring is connected to the actuator of the variable resistor to control the movement of the actuator of the variable resistor in accordance with the magnitude of the tension of the member.

(Embodiment of the Invention) An embodiment of the invention will be described below with reference to FIGS. 1 and 2.

The figure shows the liquid level detection device 1 of the embodiment installed in a fuel tank 2 of a motorcycle.

The liquid level detection device 1 includes a float 3 floating in the liquid, a sliding variable resistor (potentiometer) 4 that converts a level change in the liquid level L° into a change in electrical resistance, and the float 3.
It is comprised of a connecting body 6 that connects the slider (actuating element) 5 of the variable resistor 4, and a control spring 7 that controls the movement of the slider 5.

The float 3 has a structure in which a plurality of spherical divided floats 8 are connected by a nylon thread constituting the connecting body 6, and is bent in its length direction when suspended in a liquid. ing.

This is achieved by allowing some play when connecting the plurality of divided floats 8.

The end of the nylon thread constituting the connecting body 6 is tied to a coupling ring 10 provided at the end of the operating section 9 of the slider 5.

The control spring 7 is a coil spring, and a bracket 1 has a hook at one end hooked to a coupling ring 10 of the operating section 9 and a hook at the other end attached to the case 11 of the variable resistor 4.
2, the operating part 9 and the bracket 12
It is interposed between 0 and 0.

In the liquid level detection device having such a configuration, when the level of the liquid level L'' changes, the buoyancy of the float 3 floating in the cough fluid changes in accordance with the level change, and the connecting body 6 is thereby configured. The tension of the nylon thread changes depending on the magnitude of the buoyant force. Therefore, when the liquid level L' is at a high level where almost the entire float 3 is submerged, the buoyant force of the float 3 is large and the tension of the nylon thread is at a predetermined level. If the slider 5 is above this point, the slider 5 rotates as shown by the arrow (A) about the shaft 13 connecting the operating portion 9. At this time, the slider 5 resists the control spring 7. In addition, when the liquid level L° is at a low level that exposes a part of the float 3, the buoyancy of the float 3 is small, and the tension of the nylon thread is below a predetermined value, the slider 5 is controlled. The return force of spring 7 causes the arrow (b)
It rotates like this. This control spring 7 applies a biasing force to the slider 5 so that the tension of the nylon thread becomes a predetermined value (a value that does not cause loosening).

In the above, when the liquid level L' is at the full level, the buoyancy of the float 3 is maximum, and the slider 5, which rotates under the tension of the nylon thread due to the buoyancy, minimizes the resistance value of the variable resistor 4. . Further, as the liquid level L° approaches the level corresponding to point E of the fuel meter 14, the buoyancy of the float 3 becomes smaller, and the slider 5, which is rotated by the return force of the control spring 7, When the resistance value is increased and the liquid level L° reaches a level corresponding to point E on the fuel meter 14, the resistance value becomes maximum.

FIG. 3 shows the correlation between the liquid level L° and the buoyancy of the float 3.

According to the float 3 having the above structure, since it has flexibility in the length direction when floating in the liquid, it can float in a shape along the tank wall surface, and the liquid level L Since the buoyant force that changes depending on the level of ° is used to detect the liquid level, it is no longer affected by the shape of the tank wall, etc., and the liquid level can be measured, which was impossible with the conventional swing arm method. I can do it.

The spherical divided float 8 constituting the float 3 has the purpose of reducing collision noise when it interferes with the tank wall surface, etc.
The structure is shown in FIGS. 4 to 6. That is, the one shown in Fig. 4 is made of styrofoam material, the one shown in Fig. 5 has a rubber ball structure, and the one shown in Fig. 6 is made of a rubber ball structure.
The structure shown in the figure is the same as that shown in FIG. 4 but coated with rubber. Note that 15 in the figure is a hole through which a nylon thread is passed.

In the above embodiment, the shape of the plurality of divided floats 8 constituting the float 3 is spherical, but instead of this spherical divided float 8, a divided float 8 having a shape of two conical cones as shown in FIG. 7 is used. Then, since there is no interference between adjacent objects, the objects that are highly flexible and do not act as buoyant force as shown in the figure are definitely separated from the objects that act as buoyant force (overturn to the liquid level L''). Become.

In addition, if the float 3 is a long (band-shaped) hollow body made of a rubber-like material like the float 3° shown in FIG.
Unlike the one that connects multiple divided floats above, the liquid level L
Level changes in ° can be detected evenly and continuously (accurately).

Although the control spring 7 is a coil spring in the above embodiment, it is also possible to change the control spring 7 to a spiral spring shown in FIG. 9 or the like.

(Effects of the Invention) In summary, the liquid level detection device according to the present invention includes a float, a variable resistor that converts a change in liquid level into a change in electrical resistance, and a variable resistor that converts the float into a variable resistor. A liquid level detection device comprising a connection body connected to an actuator,
The float has a flexible structure when floating in the liquid, the connecting body is composed of a member whose tension changes due to a change in the buoyancy of the float, and the actuator of the variable resistor is provided with the member. A control spring is connected to the control spring that controls the movement of the actuator of the variable resistor according to the magnitude of the tension of the float, so that changes in the liquid level are converted to the magnitude of the buoyancy of the float suspended in the liquid. , the magnitude of the buoyant force is converted into the tension of the connecting body, and the magnitude of the tension is further detected by changing the resistance value of the variable resistor. Therefore.

Floats do not need to be displaced as the liquid level changes, and can float in the liquid following the shape of the tank wall. This has the advantage that the liquid level detection device can be installed in a small space, and even if there is a protruding part of the tank wall, the liquid level can be detected without any problem.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a fuel tank of a motorcycle using an embodiment of the present invention, Fig. 2 is a mechanism diagram of an embodiment of the invention, and Fig. 3 is a diagram showing the relationship between the liquid level and the buoyancy of the float. Diagrams showing the correlation, Figures 4 to 6 are cross-sectional views showing various structures of the divided floats that make up the float, and Figures 7 and 8 are
The figure is a side view showing the deformed structure of the float, Figure 9 is a side view showing the case where a spiral spring is used as the control spring, and Figure 1O is a schematic cross-section of a motorcycle fuel tank equipped with a conventional liquid level detection device. It is a diagram. 2...Fuel tank, 3.3'...Float, 4.
... Variable resistor, 5... Slider (actuator), 6...
Connecting body, 7...Control spring, 8.8"...Divided float, Lo...Liquid level. Applicant: Honda Motor Co., Ltd. Agent Patent Attorney: Toshihiko Watanabe Figure 1 1' Figure 3 Bribery 9 figures Leather figure 10

Claims (1)

[Claims] 1. A liquid level detection device comprising a float, a variable resistor that converts a change in liquid level into a change in electrical resistance, and a connection body that connects the float to an actuator of the variable resistor, The float has a flexible structure when suspended in the liquid, the connecting body is composed of a member whose tension changes due to changes in the buoyancy of the float, and the actuator of the variable resistor has a structure that is flexible when floating in the liquid. A liquid level detection device characterized in that a control spring is connected to control the movement of the actuator of the variable resistor according to the magnitude of tension.