JPH095145A - Liquid level detector - Google Patents

Abstract

PURPOSE: To enable connection of one end part of a terminal to a resistance plate by pressure welding while the other end part of the terminal is allowed to be connected to an external circuit by caulking. CONSTITUTION: This detector is provided with a float 20 interlocking to changes in a liquid level, resistance patterns 42 and 43 and a resistance plate 40 printed with a conductor pattern 44 connected to the resistance patterns 42 and 43, a contact 33 of a metal plate 32 fixed on the rear of a yoke 30 sliding on the conductor pattern 44 interlocking changes in the float and a terminal 50 for connecting one end 42a of the resistance pattern 42 to an external circuit. One end of the terminal 50 has a contact part electrically contacting the end 42a of the resistance pattern 42 by a spring elasticity and the other end of the terminal 50 has a caulked part 56 at which a connector terminal plate 73 extending from the external circuit is connected electrically by caulking.

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, and more particularly to a liquid level detecting device for detecting a change in liquid level as a change in electrical resistance.

[0002]

2. Description of the Related Art Conventionally, as a liquid level detecting device for detecting a change in liquid level as a change in electric resistance, for example, FIGS.
The ones shown in are known. FIG. 3 shows a front view of a liquid level detection device which is installed in a gasoline tank of an automobile and detects the liquid level in this gasoline tank, and FIG. 4 shows a cross-sectional view of a main part of FIG. There is. 3 and 4, a bearing is integrally provided in the housing 100, and a float 11 is provided at the tip of the bearing hole 101 of the bearing.
Float arm 111 with 0
The end part of the is inserted.

Bending part 11 at the base end of the float arm 111
2 is inserted into the through hole 131 provided in the resin yoke 130, and then the float arm 111 is fixed to the yoke 130 by the locking claws 132 and 133. On the back surface of the yoke 130, the plate 13 is integrally formed with the yoke 130.
4 (see FIG. 4) is fixed, and a contact 135 is formed at the tip of the plate 134. A resistance plate 140 is fixed to the housing 100, and the resistance plate 140 is mounted on the ceramic substrate 141 to form the resistance pattern 1.
42, 143 and the conductor pattern 144 connected to the resistance patterns 142, 143 are printed,
The contact point 135 slides on the conductor pattern 144.

Here, the liquid level in the gasoline tank is the liquid level A
When the liquid level drops to the position of the liquid level B, the float 110 moves downward as the liquid level decreases. With the downward movement of the float 110, the contact point 135 becomes a conductive pattern 144.
Slide up and down. The contact 135 is the conductor pattern 144.
The resistance value of the resistance plate 140 gradually increases as it slides downward, and an external circuit (not shown) notifies the decrease in the liquid level by a notifying means such as a display device (not shown).

[0005]

By the way, in the above-mentioned liquid level detecting device, the resistance pattern 142 and the external circuit (not shown) are connected to the terminal 1 as shown in FIGS.
50 and the lead wire 160. The resistance pattern 142 and the terminal 150 are connected by disposing the tip bent portion 151 of the terminal 150 above the resistance pattern 142 so that the resistance pattern 142 is connected.
The solder 155 is soldered so that the solder 155 is inserted between the end portion and the bent portion 151. However, in order to solder the resistance pattern 142 and the tip bent portion 151,
A soldering process is required, resulting in poor work efficiency and increased cost.

On the other hand, for connection between the terminal 150 and the external circuit, the other end portion 152 of the terminal 150 and the lead wire 160 extending from the external circuit are soldered by the solder 162. However, the other end 1 of the terminal 150
When 52 and the lead wire 160 are soldered, the lead wire 1
When a tensile force was applied to 60, stress was applied to the solder 162, causing a problem that the solder 162 ruptured due to creep.

In order to prevent the creep destruction due to the stress of the solder 162, the claw portions 163 and 164 are provided so as to project from the housing 100, and the lead wire 160 is clamped by the claw portions 163 and 164 a few times. Solder 162
A device was devised to prevent stress from being applied to. However, in order to prevent stress from being applied to the solder 162, the solder 162 protrudes from the housing 100 and the claws 163, 16 are formed.
4 is required, and the lead wire 160 is connected to the claw portion 1.
63,164 need to be clamped a couple of times,
As the number of parts increases, the work of clamping increases, the work time becomes longer, work efficiency decreases, and the cost increases.

Therefore, the present invention has been made in view of the above problems, and it is not necessary to solder, and one end of the terminal and the resistance plate can be connected by pressure welding, and the other end of the terminal and the external circuit. The object of the present invention is to provide a liquid level detection device that can be connected by caulking.

[0009]

SUMMARY OF THE INVENTION The present invention is a liquid level detection device for detecting fluctuations in liquid level as changes in electrical resistance,
The first feature of the configuration of the present invention is that a float that interlocks with fluctuations in the liquid level, a resistor that has a plurality of electrical contacts, and a plurality of electrical contacts of this resistor that interlock with fluctuations in the float. And a terminal for connecting a resistor and an external circuit, one end of this terminal has a contact portion that makes electrical contact with the resistor by spring elasticity, and the other end of this terminal is external. It has a caulking portion for caulking a conductor extending from a circuit and electrically connecting the conductor with the conductor.

A second characteristic feature of the present invention is that the above-mentioned terminal has an inclined portion that inclines upward from one end of the contact portion, a vertical portion that descends directly below the inclined portion, and a lower end of the vertical portion. It has a horizontal part that extends horizontally, and a caulking part is formed in this horizontal part. A third feature of the present invention is that a bent portion is provided between the inclined portion and the vertical portion, and the contact portion is provided with spring elasticity by the bent portion. A fourth feature of the configuration of the present invention is that the above-mentioned resistor has a printing resistance obtained by printing a resistance pattern on the surface of an insulating substrate. Also,
A fifth feature of the configuration of the present invention is that a folding portion is formed at a substantially central portion of the vertical portion, and the folding portion is locked to a support portion of a column integrally formed with a housing holding a resistor. Especially. Furthermore, the sixth feature of the present invention is that phosphor bronze or beryllium copper is used as the material of the above-mentioned terminal.

[0011]

In the present invention configured as described above, one end of the terminal and the resistor are electrically contacted by spring elasticity, and the other end of the terminal and the conductor extending from the external circuit are Since the electrical connection is made by caulking, the resistor can be electrically connected to the external circuit without soldering.

The terminal has an inclined portion which is inclined upward from one end of the terminal, a vertical portion which rises directly below the inclined portion, and a horizontal portion which horizontally extends from the lower end of the vertical portion and the horizontal portion. If the caulking part is formed and the bent part is provided between the inclined part and the vertical part, it is possible to give a large spring elasticity to one end of the terminal that surely comes into contact with the resistor. And one end of the terminal are in electrical contact with a small contact resistance.

Further, since the resistor is formed by a printing resistor on which a resistance pattern is printed, a stable resistance value and a highly accurate resistance value can be obtained, so that the liquid level can be changed without causing an error. It becomes possible to detect accurately. Furthermore, since phosphor bronze or beryllium copper is used as the material of the terminal, strong spring elasticity can be imparted to one end of the terminal that comes into contact with the resistor.

[0014]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a view showing an embodiment of the liquid level detecting device of the present invention, and FIG. 2 is a sectional view showing the main part thereof. 1 and 2
At, the bracket 11 is fixed to the back side of the flange 10 that closes the opening of the gasoline tank (not shown),
The bracket 11 includes a housing 12 made of synthetic resin.
Is stuck. This housing 12 is integrally provided with a bearing (not shown), and the end of the bent portion 22 at the base end of the float arm 21 having the float 20 at its tip is inserted into the bearing hole 13 of this bearing. ing. Further, the housing 12 is integrally provided with a pair of columns 14 and 15 extending in the same direction as the bearing hole 13.

The float arm 2 is attached to the resin yoke 30.
1 Through hole 31 for inserting bent portion 22 at the base end, and stop claws 34, 35 for fixing float arm 21
Is provided. The bent portion 22 at the base end portion of the float arm 21 is passed through the bearing hole 13, and the pair of columns 14 and 15 provided in the housing 12 holds the yoke 30 rotatably by a predetermined angle.

On the back surface of the resin yoke 30, a metal plate 32 is fixed integrally with the yoke 30. A contact 33 is formed at the tip of the plate 32, and the other end of the plate 32 is connected to a negative terminal 72 of a connector 70 via a spring 80 and a terminal 60.

A resistor plate 40 serving as a resistor is fixed to the housing 12, and the resistor plate 40 has resistor patterns 42 and 43 on a ceramic substrate 41 and a conductor pattern 44 connected to the resistor patterns 42 and 43. Is baked, and the contact 33 of the plate 32 slides on the conductor pattern 44. Here, the conductor pattern 44 can be said to be a plurality of electrical contacts.
One end 42 a of the resistance pattern 42 of the resistance plate 40 is connected to the positive terminal 71 of the connector 70 via the terminal 50. The other end 42b of the resistance pattern 42 is connected to one end 43a of the resistance pattern 43 via the conductor pattern 44.

Here, as the liquid level decreases, the float 20
Moving downward, the yoke 30 also moves downward with the downward movement of the float 20, and the contact 33 of the plate 32 fixed to the back surface of the yoke 30 becomes the conductive pattern 4.
4 Slide down on. As the contact point 33 of the plate 32 slides from one end 44a of the conductor pattern 44 to the other end 44b of the conductor pattern 44 as the contact point 33 slides downward on the conductor pattern 44, the resistance patterns 42, 43 are formed.
The respective resistance values are sequentially added to increase the resistance value.

The terminals 50 and 60 are
A copper alloy material for springs, which has good conductivity and spring elasticity and is easily caulked, such as a copper alloy material such as phosphor bronze or beryllium copper is used. The terminal 50 includes a contact portion 51 that contacts one end 42a of the resistance pattern 42, an inclined portion 52 that inclines upward from the contact portion 51, a vertical portion 54 that rises directly below the inclined portion 52, and a vertical portion. 5
4 has a horizontal portion 55 extending horizontally from the lower end of the connector 4, and the horizontal portion 55 has a connector terminal plate 7 extending from the connector 70.
A crimp portion 56 for crimping 3 is formed. Here, a bent portion 53 is formed between the inclined portion 52 and the vertical portion 54, and the bent portion 53 surely imparts large spring elasticity to the contact portion 51.

A gate-shaped cut 54a (not shown) is provided in the central portion of the vertical portion 54, and the gate-shaped cut 54 is formed.
By pushing the central portion of the portion a, a folded portion 54b is formed, and the folded portion 54b is engaged with the holding portion 16a of the column 16 integrally formed with the housing 12. On the other hand, the terminal 60 includes a welded portion 61 that is welded to a connecting body 62 connected to the other end of the plate 32, and a connector terminal plate 74 that extends from the connector 70.
And a caulking portion 66 for caulking.

The connector 70 has a pair of connector terminals 71 and 72 for connecting to an external circuit (not shown).
And connector terminal plates 73 and 74 extending from the respective connector terminals 71 and 72,
A slit (not shown) is provided at the center of the tip of each of the connector terminal plates 73 and 74, and each tip is formed in a bifurcated shape. By thus forming the respective tip portions of the connector terminal plates 73 and 74 in a bifurcated shape, the caulking portions 56 and 66 of the terminals 50 and 60 can be easily caulked.

In this embodiment constructed as described above, one end 51 of the terminal 50 electrically contacts with one end 42a of the resistance pattern 42 by spring elasticity, and the caulking portion 56 at the other end of the terminal 50 and the connector terminal plate. Since 73 is electrically connected by caulking, it is possible to electrically connect the resistance plate 40 and an external circuit without soldering.

The terminal 50 is the terminal 5
The inclined portion 52 inclined upward from one end 51 of 0, the vertical portion 54 standing right below the inclined portion 52, and the vertical portion 5
4 has a horizontal part 55 that is horizontal from the lower end of
Since the bent portion 53 is provided between the vertical section 54 and the vertical section 54,
A large spring elasticity can be imparted to the one end 51 of the terminal 50 that comes into contact with the resistance plate 40, and the resistance plate 40 and the one end 51 of the terminal 50 electrically contact with each other with a small contact resistance.

Further, the resistance plate 40 is connected to the resistance patterns 42, 4
Since 3 is formed by the printed resistance, a stable resistance value can be obtained and an accurate resistance value can be obtained. Therefore, it is possible to accurately detect a change in the liquid level without causing an error. . Furthermore, since phosphor bronze or beryllium copper is used as the material of the terminal 50,
Strong spring elasticity can be imparted to the one end 51 of the terminal 50 that comes into contact with the resistance plate 40.

In the above embodiment, the connector terminal plates 73 and 74 are provided so as to extend from the connector terminals 71 and 72 of the connector 70, but lead wires are used instead of the connector terminal plates 73 and 74. You may do it. Further, in the above-described embodiment, the contact portion 51 that comes into contact with the one end 42a of the resistance pattern 42 by the spring elasticity is provided only in the terminal 50.
A contact portion that contacts the connecting body 62 by spring elasticity may be provided at 0.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of a liquid level detection device of the present invention.

FIG. 2 is a sectional view showing a main part of FIG.

FIG. 3 is a diagram showing an example of a conventional liquid level detection device.

FIG. 4 is a sectional view showing a main part of FIG.

[Explanation of symbols]

10 ... Flange, 12 ... Housing, 20 ... Float,
21 ... Float arm, 30 ... Yoke, 40 ... Resistance plate,
42, 43 ... Resistance pattern, 44 ... Conductive pattern, 5
0, 60 ... Terminal, 56, 66 ... Crimping part, 70 ...
Connector, 73, 74 ... Connector terminal board

Claims (6)

[Claims] 1. A liquid level detecting device for detecting a change in liquid level as a change in electric resistance, wherein a float interlocked with the change in the liquid level, a resistor having a plurality of electrical contacts, and a plurality of resistors. A plate that slides on the electrical contact of the slider in conjunction with the fluctuation of the float, and a terminal that connects the resistor and an external circuit, and one end of the terminal is electrically connected to the resistor by spring elasticity. A liquid level detection device having a contact portion that comes into contact with the other end of the terminal, and the other end of the terminal having a caulking portion that caulks a conductor extending from the external circuit to electrically connect the conductor. 2. The terminal has an inclined portion that inclines upward from one end of the contact portion, a vertical portion that rises directly below the inclined portion, and a horizontal portion that extends horizontally from the lower end of the vertical portion. The liquid level detection device according to claim 1, wherein a caulking portion is formed on the horizontal portion. 3. The liquid level detection device according to claim 2, wherein a bent portion is provided between the inclined portion and the vertical portion, and the contact portion is provided with spring elasticity by the bent portion. 4. The liquid level detection device according to claim 1, wherein the resistor has a printing resistance in which a resistance pattern is printed on a surface of an insulating substrate. 5. A fold-in portion is formed at a substantially central portion of the vertical portion, and the fold-in portion is locked to a holding portion of a column integrally provided with a housing holding the resistor. The liquid level detection device according to claim 2. 6. The liquid level detecting device according to claim 1, wherein phosphor bronze or beryllium copper is used as a material of the terminal.