JPH11337387A - Liquid level detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a sliding contact excellent in economy, durability and reliability by forming a plurality of sliding contacts of different materials on a contact plate interlocked with a float. SOLUTION: To the contact plate 8 interlocked with a float contacts 11, 12 sliding on a conductor pattern 4 are secured through a caulking means, or the like. The sliding contacts 11, 12 arranged at positions touching an identical conductor pattern 4 in order to ensure an identical detecting position or at positions touching adjacent slave conductor patterns 4, respectively, and means output is obtained. The sliding contact 11 is made of silver palladium alloy and the sliding contact 12 is made of silver nickel alloy, for example. More specifically, one material is excellent in durability while the other material is excellent in contact reliability and the performance is complemented each other. This arrangement realizes a sliding contact excellent in economy, durability and contact reliability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid level detecting device for measuring a liquid level in a fuel tank of a vehicle or the like, and more particularly to a liquid level detecting device characterized by a sliding contact sliding on a conductor pattern on an insulating substrate. Related to the device.

[0002]

2. Description of the Related Art Conventionally, a liquid level detecting device 1 is housed in a fuel tank 2 and is provided on a mounting plate 3 attached to an opening of the fuel tank 2. Under the mounting plate 3, an insulating substrate 6 made of ceramic on which a conductor pattern 4 and a resistor 5 are formed by printing is mounted. Further, the liquid level detecting device 1 is provided with a contact plate 8 having a sliding contact 7 that slides on the conductor pattern 4. This contact plate 8
From the float 9 that moves up and down according to the fuel level,
In addition, it is supported and fixed on the insulating substrate 6 so as to be able to move in accordance with the liquid level through the insulating substrate 6. Therefore, the vertical movement of the liquid surface is transmitted to the contact plate 8 via the float 9 and the arm 10, and the sliding contact 7 slides on the conductor pattern 4, thereby sliding with the conductor pattern 4 on the insulating substrate 6. The resistance value changes depending on the position of the conductor pattern 4 in contact with the contact 7, whereby the amount of liquid in the fuel tank 2 is detected and displayed on a display (not shown).

[0003]

However, the material used for the sliding contact 7 is hardly sulfided by a sulfur component contained in fuel (gasoline) and has high wear resistance.
Although it is an alloy of silver-palladium, this silver-palladium is a noble metal-based alloy and very expensive, so that it lacks economy. Another material used for the sliding contact 7 is an alloy of silver-nickel, etc., which is easily sulfided compared to silver-palladium and cannot have the durability as high as silver-palladium. It was soft, had good contact with the conductor pattern, and had excellent contact reliability.

Accordingly, the present invention focuses on the above-mentioned problems, and provides a liquid level detecting device using sliding contacts excellent in economy, durability and contact reliability by using different materials for the sliding contacts. is there.

[0005]

In order to achieve the above object, the present invention provides a float operating following a liquid level in a fuel tank, and a sliding contact provided on a contact plate interlocked with the movement of the float. And a liquid level detection device having an insulating substrate provided with a conductor pattern on which the sliding contact slides, wherein a plurality of the sliding contacts are provided, and the sliding contacts are formed of different materials.

Further, the material used for the sliding contact is:
It is a combination of any of silver palladium, silver nickel, silver tin, nickel and nickel chrome.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a liquid level detecting device 1 of the present invention, two sliding contacts 11 and 12 sliding on a conductor pattern 4 are fixed to a contact plate 8 interlocking with a float 9 by caulking means. ing. As for the material of the two sliding contacts 11, 12, one of the sliding contacts 11 is a silver-palladium alloy and the other is a silver-nickel alloy.

Further, the material used for the sliding contact is
A combination of any of silver palladium, silver nickel, silver tin, nickel, and nickel chrome may be used.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described with reference to FIGS. 1 and 2, but the same parts as those in the above-mentioned conventional example will be denoted by the same reference numerals and detailed description thereof will be omitted.

FIG. 1 is a front view of a main part of a liquid level detecting device according to the present invention, and FIG. 2 is a sectional view of a main part of the liquid level detecting device according to the present invention.

As shown in FIGS. 1 and 2, the liquid level detecting device 1 of the present invention forms a plurality of rows of conductor patterns 4 in a fan shape, for example, by printing on an insulating substrate 6 made of ceramic at appropriate intervals. The resistor 5 covers a part of the conductor pattern 4 in a plurality of rows by, for example, printing. Two sliding contacts 11 and 12 that slide on the conductor pattern 4 are fixed to the contact plate 8 interlocked with the float 9 by means such as caulking.

In addition, the same detection position can be ensured by contacting the same conductor pattern 4 with respect to the disposing position of such a sliding contact. For example, each of the contact points is in contact with the adjacent child conductor pattern 4. And the average output may be obtained.

The materials of the two sliding contacts 11 and 12 are as follows:
One sliding contact 11 is a silver-palladium alloy, and the other sliding contact 12 is a silver-nickel alloy. The amount of each alloy is not particularly limited. The selection of these materials may be a combination that complements each other so that one material has excellent durability and the other material has excellent contact reliability.

As described above, by using a silver-palladium alloy as the material of one of the two sliding contacts 11 and 12, it is possible to obtain a high resistance to sulfuration and the other sliding contact. By using a silver nickel alloy as the material of the moving contact 12, contact reliability can be obtained. As described above, by using materials having different properties for the sliding contacts 11 and 12, the advantages of both materials can be utilized.
Liquid level detector 1 excellent in economy, durability and contact reliability
Can be obtained.

The materials that can be used for the sliding contacts 11 and 12 are not limited to silver palladium and silver nickel of the above-described embodiment.
There are silver-tin alloy, nickel, nickel-chromium alloy and the like, and two of these materials may be selected and appropriately combined to be used for the sliding contacts 11 and 12. By combining these materials, sliding contacts with desired characteristics, such as those that are more economical, more durable, and more reliable in contact, and that are more durable and liquid level detectors that are more highly reliable in contact, are available. Can be obtained.

[0016]

As described above, according to the present invention, an intended object can be achieved, and a liquid level detecting device using a sliding contact excellent in economy, durability and contact reliability can be obtained.

Further, since there are a plurality of materials applicable to the sliding contact, it is possible to obtain a liquid level detecting device provided with the sliding contact having desired characteristics.

[Brief description of the drawings]

FIG. 1 is a front view of a main part of a liquid level detecting device according to the present invention.

FIG. 2 is a sectional view of a main part of the liquid level detecting device according to the present invention.

FIG. 3 is a diagram in which a conventional liquid level detecting device is attached to a fuel tank.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Liquid level detection device 2 Fuel tank 3 Mounting plate 4 Conductor pattern 5 Resistor 6 Insulating substrate 7, 11, 12 Sliding contact 8 Contact plate 9 Float 10 Arm

Claims (2)

[Claims] 1. A float which operates following a liquid level in a fuel tank, a sliding contact provided on a contact plate interlocked with the movement of the float, and a conductor pattern on which the sliding contact slides. In a liquid level detection device having an insulating substrate,
A liquid level detecting device, wherein a plurality of the sliding contacts are provided, and the sliding contacts are formed of different materials. 2. The liquid level detecting device according to claim 1, wherein a material used for the sliding contact is a combination of any one of silver palladium, silver nickel, silver tin, nickel and nickel chrome.