WO2004031705A1

WO2004031705A1 - Liquid level-detecting device

Info

Publication number: WO2004031705A1
Application number: PCT/JP2003/011666
Authority: WO
Inventors: Tetsuya Sato; Takayuki Yamaura; Shigeki Koide; Tadao Nakagawa
Original assignee: Nippon Seiki Co.,Ltd.
Priority date: 2002-09-30
Filing date: 2003-09-11
Publication date: 2004-04-15
Also published as: JP2004125497A

Abstract

A liquid level-detecting device having reliable electrical conductivity, being small in size and excellent in wear resistance of a contact. A liquid level-detecting device (1) comprises a circuit substrate (2) with electro-conductive bodies (3, 8), slide contacts (6, 7) sliding on the electro-conductive bodies (3, 8) as a liquid level varies, and a slider (5) to which the slide contacts (6, 7) are fixed. Elastically deformable arm pieces (511, 512, 521, 522) are provided at the slider (5), and slide contacts (61, 62, 71, 72) are welded and fixed to the individual arm pieces (511, 512, 521, 522).

Description

Description Wavefront detector Technical field

The present invention relates to a liquid level detecting device, and more particularly to a liquid level detecting device in which a sliding contact slides due to a change in the liquid level. Background art

In a conventional liquid level detection device, a resistance path made of a resistance material is provided on a circuit board, a conductor path made of a conductive material is provided along the resistance path, and a contact point sliding on the conductor path is provided. What is provided is disclosed in Japanese Utility Model Application Laid-Open No. 62-40528.

In such a liquid level detecting device, since one contact slides on the conductor path, there is a possibility that an insulating state may occur if a foreign object or the like is caught between the conductor path and the contact.

Therefore, in order to suppress the occurrence of insulation due to pinching of foreign matter and improve the reliability of energization, one contact is provided with a plurality of contact points that contact the conductor path. It is shown in 632 publication.

In such a liquid level detection device, it is possible to reduce the insulation state due to pinching of foreign matter or the like, but since it is a single contact, depending on the size of the foreign matter, any contact point and conductor path If a foreign object is interposed between the conductors, all the contact points are separated from the conductor path, and there is a possibility that the contact point may still be insulated.

Therefore, there is a type in which two contacts are provided to further suppress the occurrence of an insulated state due to pinching of a foreign substance and to improve the reliability of energization. In this liquid level detection device, two contacts are provided so as to move separately, and a foreign object is interposed between one contact and a conductor track, and even if one contact is separated from the conductor path, the other contact is separated from the other conductor. The contact is hardly affected by one contact and can maintain contact with the conductor path.

— See 3 3 7 3 8 7

In such a liquid level detection device, since the contacts are fixed to the contact plate by means such as caulking, the size has to be large, and there is a limit to miniaturization. I got it.

Therefore, in order to suppress the occurrence of insulation due to pinching of foreign objects and to improve the reliability of energization, one of the measures to reduce the size is to provide a plurality of contacts extending from the contact plate. In the liquid level detecting device as disclosed in the specification of Japanese Patent No. 5746680, the contact is a plate-shaped member.

No. 6 2-400 5 28, Japanese Patent Application Laid-Open No. 2000-40663 2 and Japanese Patent Application Laid-Open No. 11-3

There was a problem that the abrasion resistance was lower than that of the contact point in the Japanese Patent Publication No. 373887.

Accordingly, the present invention is to provide a liquid level detection device that is small in size while ensuring energization reliability and is excellent in abrasion resistance of contacts. Disclosure of the invention

In order to achieve the above object, the present invention provides a circuit board having a conductor, a sliding contact that slides on the conductor according to a change in liquid level, and an inserter to which the sliding contact is fixed. In the liquid level detecting device provided, a plurality of elastically deformable arms are provided on the slider, and the sliding contacts are welded and fixed to each of the arms.

Also, a circuit board having a plurality of fixed electrodes connected to a resistor, a sliding contact for driving the fixed electrode in accordance with a change in liquid level, and a slider to which the sliding contact is fixed are provided. A liquid level detection device that outputs a resistance value of the resistor corresponding to the arbitrary fixed electrode when the sliding contact contacts an arbitrary fixed electrode from among the plurality of fixed electrodes. A plurality of elastically deformable arm pieces are provided on the slider, and the sliding contacts are welded and fixed to each of these arm pieces.

Further, the automatic contact is a three-dimensional object.

Further, the sliding contact is formed of nickel silver.

The liquid level detecting device 1 of the present invention includes a circuit board 2 provided with 38, a sliding contact 67 sliding on the conductors 3 and 8 according to a change in the liquid level, and an automatic contact 67 fixed. In the liquid level detecting device 1 provided with the slider 5 to be provided, the arm 5 is provided with a plurality of arms 5 1 1 5 1 2, 5 2 1, 5 2 2 which can be elastically deformed. 5 1 2, 5

Sliding contacts 6 1 6 2 7 1 7 2 are welded and fixed to 2 1 5 2 2 respectively. With this configuration, it is possible to secure energization reliability and reduce the size. In addition, it is possible to provide a liquid level detection device having excellent contact resistance.

Further, a circuit board 2 having a plurality of fixed electrodes 3 connected to the resistor 4, a sliding contact 6 for driving the fixed electrode 3 in accordance with a change in the liquid level, and the sliding contact 6 are fixed. A slider 5 is provided, and a sliding contact 6 contacts an arbitrary fixed electrode 3 among a plurality of fixed electrodes 3 to output a resistance value of a resistor 4 corresponding to the arbitrary fixed electrode 3. In the liquid level detection device 1, the slider 5 is provided with a plurality of elastically deformable arm pieces 5 1 1 and 5 1 2, and each of the arm pieces 5 1 1 and 5 1 2 has sliding contacts 6 1 and 6. 2 is welded and fixed. With such a configuration, it is possible to provide a liquid level detection device which is small in size while ensuring the reliability of energization and excellent in wear resistance of the contacts.

The sliding contacts 61, 62, 71, and 72 are three-dimensional objects. With such a configuration, it is possible to provide a liquid level detection device that is small in size and has excellent contact wear resistance while ensuring the reliability of energization.

In addition, the moving contacts 61, 62, 71, 72 are made of nickel-white. With such a configuration, it is possible to provide a liquid level detection device which is small in size and has excellent contact wear resistance while ensuring the reliability of energization. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a front view of one embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line AA in FIG. 1, and FIG. 3 is a perspective view of a slider of the embodiment. FIG. BEST MODE FOR CARRYING OUT THE INVENTION ''

1 to 3 are front views of an embodiment of the present invention, and a case where the present invention is applied to a liquid level detecting device provided in a fuel tank of a vehicle such as an automobile will be described as an example.

The liquid level detecting device 1 includes a circuit board 2 made of ceramic or the like, a plurality of fixed electrodes 3 which are formed by printing on the circuit board 2 and are a plurality of conductors on which sliding contacts described later slide, and a plurality of fixed electrodes. A resistor 4 connected so as to straddle 3, a slider 5 rotating around a fulcrum (not shown), a first sliding contact 6 and a second sliding contact provided on the slider 5 And 7. The fixed electrode 3 is composed of silver, palladium and glass. Have been.

The conductor 8 and the conductors 9 and 10 on which the second sliding contact 7 slides are formed on the circuit board 2 in the same manner as the fixed electrode 3, and the adjusting resistor 11 is the same as the resistor 4. It is formed in the process. Lead wires 12 are connected to the connection lands 9a and 10a of the conductors 9 and 10 by solders 13 respectively, and are connected to a not-shown instrument driving means. The first sliding contact 6 is composed of a plurality of, for example, two sliding contacts 61 and 62 in the present embodiment with respect to the fixed electrode 3 which is a conductor. The term “for the fixed electrode 3” refers to a slide path formed by the plurality of fixed electrodes 3 and on which the first sliding contact 6 slides. Further, the second sliding contact 7 is also provided with a plurality of the sliding contacts 7 with respect to the conductor 8, and in this embodiment, is constituted by two sliding contacts 7 1 and 7 2.

As shown in Fig. 3, the two first sliding contacts 61 and 62 and the two second sliding contacts 71 and 72 are fixed to a U-shaped plate-like slider 5. The first sliding contact 6 1, 6 2 and the second sliding contact 7 1, 7 2 are separated into a first arm piece 5 1 and a second arm piece 5 2, respectively. Further, the first arm piece 51 and the second arm piece 52 are further divided into two arm pieces 51 1, 51 2, 52 21 and 52 2 respectively. The first arm piece 51 and the second arm piece 52 have elasticity, but the arm pieces 51 1, 51 2, 52 21 and 52 2 have further elasticity. First and second sliding contacts 6 1, 6 2, 7 1, 7 2 are fixed to the arm pieces 5 1, 5 12, 5 2 1, 5 2 2 by welding. Further, the first and second sliding contacts 61, 62, 71, 72 are formed in a rectangular solid object in white. The slider 5 is made of phosphor bronze or nickel silver. With the above-described configuration, for example, even if a foreign object enters between the first sliding contact 61 and the fixed electrode 3, the elastic arm pieces 511 and 512 are elastically deformed. By shaping, the other first sliding contact 62 can satisfactorily come into contact with the fixed electrode 3, and energization reliability can be secured.

Also, the first and second sliding contacts 61, 62, 71, and 72 are fixed by welding, for example, by electric welding or the like. It is possible to make the contact 61, 62, 71, 72 compact with a small space between them. In addition, the sliding contacts 6 1, 6 2, 7 1, and 7 2 are formed as rectangular three-dimensional objects. 2, 7 1, 7 2 Can be obtained. The shape of the three-dimensional object of each of the sliding contacts 61, 62, 71, and 72 may be any shape as long as the shape can improve wear resistance. As described above, due to the improved wear resistance, the fixed electrode 3 and the like are provided with a hard protective film, for example, ruthenium oxide or the like in order to prevent the silver constituting the fixed electrode 3 from being sulfurized. , Sufficient abrasion resistance can be obtained. In this embodiment, the sliding contacts 61, 62, 71, 72 are provided in the middle of the U-shaped arms 511, 51, 52, 52, 52. However, the shape of the arm piece is not limited to the above embodiment, and may be any shape as long as it has elasticity.

In the above embodiment, the arm pieces 5 1 1, 5 1 2, 5 2 1, 5 2 2 are combined into the first and second arm pieces 5 1, 5 2, but the first The arm 5 and the second arm 52 may not be provided, and the slider 5 may form four arms 5 11, 5 12, 5 2 1, 5 2 2 respectively. Industrial applicability

INDUSTRIAL APPLICABILITY The present invention can be applied to a liquid level detecting device, and is particularly suitable for a liquid level detecting device that requires a small size and abrasion resistance of a contact while ensuring energization reliability.

Claims

The scope of the claims

1. A liquid level detecting device including a circuit board having a conductor, a sliding contact that slides on the conductor with a change in the liquid level, and a slider to which the sliding contact is fixed. A liquid level detecting device, wherein a plurality of elastically deformable arm pieces are provided on the slider, and the sliding contacts are welded and fixed to each of the arm pieces.

2. A circuit board having a plurality of fixed electrodes connected to a resistor, a sliding contact for driving the fixed electrode as the liquid level changes, and a slider to which the sliding contact is fixed. A liquid level detection device that outputs a resistance value of the resistor corresponding to the arbitrary fixed electrode by contacting the helix contact with an arbitrary fixed electrode from among the plurality of fixed electrodes. A liquid level detecting device, wherein a plurality of elastically deformable arm pieces are provided on the slider, and the sliding contacts are welded and fixed to each of the arm pieces.

3. The liquid level detecting device according to claim 1, wherein the sliding contact is a three-dimensional object.

4. The liquid level detecting device according to claim 3, wherein the sliding contact is formed of nickel-white.