JPS6315122A - Liquid level detector - Google Patents

Abstract

PURPOSE:To connect heat-sensitive elements in parallel without thermally damaging said elements, by a method wherein a reticulated conductors each having a wide area and rich in flexibility is brought into contact with both electrode surfaces of the heat-sensitive elements and the heat-sensitive elements are held between the reticulated conductors by C-shaped clip members. CONSTITUTION:A plurality of heat-sensitive elements 1 such as thermistors or PTC are arranged in a row and reticulated conductors 2 each having a wide area and rich in flexibility comprising a knitted metal net provided with projections at the same interval as the heat-sensitive elements 1 are abutted on both electrode surfaces of the heat-sensitive elements 1. Then, the reticulated conductors wherein the elements 1 are placed between the projections 3 are grasped by C-shaped clips 4 each made of a synthetic resin having high electric and thermal insulating property and having leading end grasping parts provided at an interval almost same or slightly narrower than the thickness of each heat-sensitive elements.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid level detector for detecting the fuel level in the fuel tank of an automobile, the oil level in the engine, and the like.

1. A liquid level measuring device δ that uses a positive humidity characteristic thermistor (hereinafter referred to as PTC) as a small and highly reliable liquid level detector without any mechanical moving parts was published in Japanese Patent Publication No. 55-688. It existed as shown.

In this liquid level measuring device, circular holes 03 are provided at constant intervals in the longitudinal direction in the vertically long thermally insulating holder 02, and the circular holes 03 are arranged so as to communicate with each other.
4 and lead wires O on both sides of the short cylindrical PTCOl.
5 and 06 are connected in parallel, this PTCOl is fitted into the circular hole 03, the lead wire 05 is inserted into the hole 04, and a heat insulating cover plate 08 is attached to the other side 07 of the heat insulating holder 02. They were connected together.

In the liquid level measuring device described above, it is necessary to solder to connect the lead wires 05.06 to both sides of the PTCOl. There is a risk of damage, and it is difficult to solder the thin lead wires 05.06 to both sides of the PTCOI while keeping the interval between the PTCOI constant.
When inserting the lead wire 05 into the lead wire 4, it is customary to hook the lead wire 05 and separate the connection part or break the lead wire 05.

, 1" - and 20. The present invention relates to an improvement of a liquid level detector that overcomes the above-mentioned point (1). In a liquid level detector for detecting liquid level, a highly flexible mesh conductor with a large surface area is brought into contact with both electrode surfaces of the heat sensitive element, and a C-shaped holding member is used to hold the heat sensitive element in contact with the mesh conductor. A plurality of heat-sensitive elements can be electrically connected in parallel by being held between the body.

An embodiment of the present invention illustrated in FIGS. 2 to 7 will be described below.

In this example, PTCI is used as a heat-sensitive element that generates heat by itself and has a property that its electrical resistance value changes with temperature changes. A platinum resistance temperature sensor may also be used.

In addition, the knitting table ff142 made of copper or the like, which also serves as a holding member for the PTCI and has a net-like structure, has a width slightly wider than the width of the PTCI, and as shown in FIGS. 2 and 6, A protrusion 3 is provided at approximately the center of the protrusion 3 at an interval equal to one PTCl arrangement, and protruded by a pump or the like (not shown).

Furthermore, C made of synthetic resin has high electrical and thermal insulation properties.
A letter-shaped grip 4 is formed, and the interval between the tip clamping parts 5 is set to be approximately the same as the J grip of the two grips C1, or slightly narrower.

The heat dissipation case 6 made of synthetic resin or the like is formed to a thickness that allows the C-shaped grip 4 to fit comfortably therein, and a cap 9 made of an electrically insulating material is fitted into and removed from the opening 7 of the heat dissipation case 6. The upper end of the knitting table m2 is soldered to the electrode terminal 10.11 which is freely fitted and integrally provided on this cap 9.
etc. are connected together.

Moreover, the outer peripheral surface of the opening 7 of the heat dissipation case 6 has a training screw portion 8.
The male threaded part 8 of the heat dissipation case 6 is removably screwed into the female threaded part 14 provided in the opening 13 of the fuel tank 12 via a packing 15.

Since the embodiments shown in FIGS. 2 to 7 are formed as described above, the side surfaces of the PTCl slightly protrude from the side edges of the knitted wire mesh 2, and the protrusions of the two knitting tables W12 3, place PTCl between the protrusions 3, sandwich the tip holding part 5 of the C-shaped grip 4 on the surface of the knitted wire mesh 2, and fit it into the heat dissipation case 6. By screwing it into the opening 7 of the heat dissipation case 6, the liquid level detector can be assembled.

In this liquid level detector, when the male threaded portion 8 of the heat dissipation case 6 is screwed onto the female threaded portion 14 of the fuel tank 12,
When connected to a power source via a current J] (not shown) to the electrode terminals 10.11, the PTCI generates heat by itself, and the heat is transferred to the fuel m1. : be swept away.

The heat dissipation case 6 is immersed in the fuel t4L in the fuel tank 12,
When the liquid level 13 is high, the number of PTCl cooled by the fuel is large and its electrical resistance is low, so the pointer of the ammeter swings greatly.

However, when the fuel level is saturated and the liquid level LS decreases, the number of PTCIs cooled by the fuel level decreases, and their electrical resistance increases, so the deflection of the ammeter pointer decreases.

In addition, the knitted wire mesh 2 has appropriate rigidity and elasticity, and the protrusions 3 protrude from the knitted wire mesh 2, and the tips of the protrusions 3 are made of PTC.
P is in contact with both sides of
Since TCl is sandwiched between knitting wire mesh 2, PTCI and knitting stand #! 2 is connected with the same electrical conductivity as when PTCl and the lead wire are soldered, and the required detection characteristics can be obtained.

Furthermore, since the liquid level detector can be assembled by the operations described above, it can be produced with great efficiency and at low cost.

Furthermore, since the PTCl and the knitted wire mesh 2 can be connected without soldering, there is no risk of damaging the PTCl, and because the knitted wire mesh 2, which has a relatively wide band shape, is used without using lead wires. , I'm not used to disconnections.

Moreover, since PTCl is sealed by the heat dissipation case 6 and the cap 9, it does not come into contact with moisture, dust, etc., and stable characteristics can be obtained over a long period of time, resulting in good durability.

In the embodiments shown in FIGS. 2 to 7, a knitted wire mesh 2 is used as the mesh conductor, but as shown in FIG. You can.

In addition, in the embodiments shown in FIGS. 2 to 7, the PTCl
, the knitted wire mesh 2 and the C-shaped grip 4 are sealed with the heat dissipation case 6 and the cap 9, but as shown in FIGS. 9 to 11, these may be tightly connected together with a synthetic resin 18 without any gaps .

As described above, in the present invention, a plurality of heat-sensitive elements can be electrically connected in parallel by sandwiching the heat-sensitive elements between the mesh electrodes using the C-shaped holding member without using soldering. Therefore, the liquid level detector can be efficiently and reliably assembled while avoiding thermal damage to the heat-sensitive element due to soldering.

Further, in the present invention, the member for electrically connecting the heat-sensitive element is not a thin lead wire but a wide net-like conductor, which has high mechanical strength and is free from breakage.

[Brief explanation of the drawing]

Figure 1 is an exploded perspective view of a conventional liquid level measuring device;
The figure is an exploded perspective view of essential parts of an example of actual flow of a liquid level detector according to the present invention, FIG. 3 is a cross-sectional front view of the embodiment, and FIG. 5 is a cross-sectional plan view taken along line v-v in FIG. 3; FIG. 6 is a schematic front view exaggerating the main parts of FIG. 3; FIG. 7 is a plan view of a knitted wire mesh, FIG. 8 is a plan view of a perforated wire mesh according to another embodiment, FIG. 9 is a longitudinal cross-sectional side view of yet another embodiment, and FIG. 10 is a FIG. 11 is a longitudinal sectional front view taken along the line Xa, and FIG. 11 is a cross-sectional plan view taken along the X[-XI line in FIG. 1...PTC, 2...Knitted wire mesh, 3...Protrusion, 4
...C-shaped grip, 5...Tip clamping part, 6...
Heat dissipation case, 7... Opening, 8... Male screw part, 9.
...Cap, 10°11...Electrode terminal, 12...
Fuel tank, 13...Opening, 14...Female threaded part, 1
5...Packkin, 16...Porous wire mesh, 17...
Small hole, 18...Synthetic resin, L...Fuel, 1s...
Liquid surface. Agent Patent attorney Nozomu Ehara and two others Figure 4 Figure 7 Figure 8 Figure 9 1. Indication of the case 1986 Patent Application No. 158747 2. Name of the invention Liquid level detector 3, Person making the amendment Relationship to the case Patent applicant address 2-1-1 Minami-Aoyama, Minato-ku, Tokyo Name (532) Honda Motor Kosen Co., Ltd. Representative Kumeashishi 4, Agent Address 2-3-3-6 Toranomon, Minato-ku, Tokyo Number of inventions increased by amendment None 7 Pair of amendments. 1) Page 3, lines 3 to 5, "The surface area is wide...
Correct "to a conductor" as follows. "A highly flexible conductor is brought into contact with the conductor, and the heat-sensitive element is attached to the conductor using a clamping member." 2) "High composition" in the second line of page 4 is corrected to "composition with high elasticity." To do. 3) Page 4, line 3, lines 6 to 7, page 5, line 2
Change the "C-shaped grip" from row to line 3, page 6, line 3 to line 4, page 7, line 6, and page 8, line 14 to line 15 to the "C-shaped holding member". I will correct it. 4) Change “on the surface” to “on the surface” in the second line of page 5, and change it to “on the surface” in the third line of the same page.
Correct "Tip clamping part 5" in the row to "Tip clamping part 5". 5) Insert the following between page 7, line 4 and line 5. "Moreover, as shown in FIG.
may be held between the two. 6) Insert the following between page 7, line 9 and line 10. [Furthermore, the clamping member may have a structure in which the clamping member does not have elasticity and is clamped by screws or the like. As a specific example, the embodiment shown in FIGS. 13 to 15 will be described. A conductor 25 with a conductive material 24 printed on one side of the film substrate 23 is used, the conductive material 24 is brought into contact with both sides of PTCl, and the channel-shaped clamping member 26 is aligned so as to be located outside of the PTCI. The conductor 25 may be brought into pressure contact with the PTCl by the channel-shaped holding member 26 by screwing in the screw 27 that is screwed into the channel-shaped holding member 26. 7) Correct "In this way...because it is a conductor" in lines 11 to 19 of page 7 as follows. ``As described above, in the present invention, a plurality of heat-sensitive elements can be electrically connected by sandwiching the heat-sensitive element between the electric picks using a clamping member without using soldering. Avoid thermal damage and reduce defective rate.
A liquid level detector can be assembled efficiently and reliably. Furthermore, in the present invention, the member that electrically connects the heat-sensitive element is not a thin lead wire but a conductor with a width. ” is corrected as follows. "A cross-sectional plan view, FIG. 12 is an exploded perspective view illustrating still another embodiment of the present invention, FIG. 13 is an exploded perspective view illustrating another embodiment of the present invention, and FIGS. 14 and 15. are a vertical cross-sectional view and a cross-sectional view of the main parts thereof.'' 9) The ``Claims'' will be amended as shown in the attached sheet. Drawings Figures 12 and 13 are attached to the original drawings of the application. Figures 14 and 15 will be added. Claims: ``A liquid level detector that detects the height of a liquid by being immersed in a liquid using a plurality of heat-sensitive elements, in which n is brought into contact with both electrode surfaces of the heat-sensitive elements. , 9 shu -n b
A liquid level detector characterized in that a heat-sensitive element in front of -, τ is sandwiched between the turrets υ. "Figure 12, 1 Figure 15 No. 125

Claims (1)

[Claims] In a liquid level detector that detects the height of a liquid by being immersed in a liquid using a plurality of heat-sensitive elements, a highly flexible mesh conductor with a large surface area is brought into contact with both electrode surfaces of the heat-sensitive elements. ,
A liquid level detector characterized in that the heat-sensitive element is held between the net-like conductor by a C-shaped holding member.