JPH0425622Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a liquid level detection device, and more specifically,
The present invention relates to a liquid level detection device that is used for detecting the remaining amount of fuel in a vehicle, and detects a change in the liquid level as a change in electrical resistance by having a contact slide on a resistor as a float moves.

[Problems to be solved by conventional techniques and ideas]

An example of a conventional liquid level detection device will be explained with reference to FIGS. 4 to 6.

FIG. 4 is a top view, a front view, and a sectional view of the liquid level detection device (detection sensor).

The outer cylinder 1 is closed at the bottom by a bottom plate 2 and at the top by a flange 3, and has a resistor 4 and a float 5 inside.
is stored. The resistor 4 has a pair of resistors 4a and 4b arranged side by side in a strip shape, and one end of the resistors 4a and 4b is led out onto the flange 3 by lead wires 6 and 7, and is connected to a liquid level detection device (not shown). connected to the meter. The float 5 is movable up and down within the outer cylinder 1 while facing the resistance plate 4, and moves up and down in response to changes in the liquid level (not shown) with respect to the fixed outer cylinder 1.

FIG. 5 is a diagram showing the relationship between the resistors 4a, 4b and the float 5. The resistor plate 4 is located in the center hole 5a of the float 5, and the inside of the hole 5a of the float 5 is made of conductive metal. A contact 8 is attached, and a free end 8a of the contact 8 is in contact with the resistors 4a, 4b on the resistor plate 4.

In the above liquid level detection device, when the float 5 moves up and down with respect to the resistance plate 4 in response to changes in the liquid level,
The contact 8 slides on the resistors 4a and 4b,
Since the short-circuit point (depending on the contact 8) between the resistors 4a and 4b is changed, the electrical resistance value between the lead wires 6 and 7 is changed. As a result, by using a meter to indicate a change in current that accompanies a change in resistance value, changes in the liquid level (remaining amount) of fuel or the like can be displayed.

Incidentally, in the liquid level detection device described above, in many cases, one end of the contact 8 is fixed integrally by insert molding when the float 5 is molded, as shown in FIG. However, fixing the contacts using inserts requires an expensive mold, and the time required for molding is long, resulting in an increase in costs. In addition, the contact may be deformed by the heat during insert molding, and if the deformation is large, the contact pressure with the resistor becomes unstable, leading to poor contact and early wear.

FIG. 6 shows an example in which the contacts 8 are fixed by welding 9. As shown in FIG. However, in this conventional example, the workability of attaching the contacts 8 is not good, as a special jig is required for welding.

The present invention has been devised in view of the above points, and an object of the present invention is to provide a liquid level detection device in which contacts can be installed reliably, the installation workability is good, and costs can be reduced.

[Means for solving problems]

In order to achieve the above object, the liquid level detection device according to the present invention has a resistor inserted through a hole formed in the center, and the contact slides on the resistor as the float moves, thereby detecting the liquid level. In a liquid level detection device that detects a change as a change in electrical resistance, a groove of a predetermined width is formed on the upper surface of the float around the hole, and a contact is formed in the hole on the side opposite to the side in contact with the resistor. A bent part is formed at the end of the float so as to follow the upper surface of the float and an inner wall of the groove connected thereto, and at the end where the bent part is extended into the groove, a V-shape is formed on the outside. A fitting portion having elasticity is bent into a shape, and a locking pawl that bites into the inner wall is formed in the middle of an extension portion that contacts an inner wall of the groove, and the fitting portion is inserted into the groove. The contact is press-fitted and the locking pawl bites into the inner wall of the groove to attach and fix the contact to the float.

[Effect]

In the above configuration, the end of the contact opposite to the side that contacts the resistor in the hole through which the resistor is inserted has a bent portion that is bent to follow the upper surface of the float and the inner wall of the groove connected thereto. is formed, and at the end of this bent part extending into the groove, an elastic fitting part bent outward in a V-shape is formed, so that the fitting part can be press-fitted into the groove. By doing so, the bent portion is fixed following the upper surface and inner wall of the float, and the contact is positioned. In addition, a locking pawl that bites into the inner wall is formed in the middle of the extension part that contacts the inner wall of the groove, and when the fitting part is press-fitted into the groove, this locking pawl bites into the inner wall of the groove. , the positioned contacts are securely fixed in that position.

〔Example〕

FIG. 1 is a sectional view of a main part of an embodiment of the present invention, showing a state in which the contact 8 is fixed. As shown in the figure, a hole 5a through which the resistance plate 4 is inserted is provided in the center of the float 5, and a groove 5b of a predetermined width is formed in the upper end surface of the periphery thereof. This groove 5
b is formed when the float 5 is molded.

One end of the contact 8 is attached within this groove 5b. The contact 8 has two bent parts,
A first bent part 8b at the center in the longitudinal direction is bent into a U-shape along the cross-sectional shape of the float 5, and a second bent part at the end opposite to the free end 8a that contacts the resistors 4a and 4b. Due to its elasticity, it comes into pressure contact with the walls on both sides of the groove 5b to form a fitting portion 8c to the groove 5b. Further, the fitting part 8c has an integral locking pawl 8d projecting outward in a part thereof, and this locking pawl 8d bites into the inner wall surface of the groove 5b to prevent the contact 8 from coming off. Incidentally, since the float 5 is made of a lightweight and relatively flexible synthetic resin material such as foamed rubber, it is easy for the locking pawl 8d of the contact 8 to bite into the float 5.

FIG. 2 is a front view and both side views of the contact 8, and FIG. 3 is a perspective view thereof.

The contact is made of an elastic conductive metal material such as phosphor bronze, and as described above, the first
The bent portion 8b, the fitting portion 8c, the locking claw 8d, and the curved free end 8a are all formed by press molding. In this embodiment, the free end 8a has two arms that contact the two resistors 4a and 4b independently, and the locking claw 8d has two triangular pieces as seen in FIG. It consists of two tapered nails that have been punched out.

Contact 8 and resistor 4a in this embodiment,
4b is the same as in the conventional example, however, when assembling the contact 8, the first bent portion 8b and the fitting portion 8c of the contact 8 are aligned with the groove 5b on the float 5 after molding. Just insert it from above. As a result, the contact 8 is securely fixed to the float 5 due to the elasticity of the fitting portion 8c and the biting of the locking claw 8d.

[Effect of idea]

As explained above, according to the present invention, by press-fitting the fitting part into the groove, the bent part is fixed following the upper surface and inner wall of the float, and the float is positioned and fitted. When the contact is press-fitted into the groove, the locking pawl bites into the inner wall of the groove, so that the positioned contact is securely fixed at that position without falling off.

Therefore, there is no need for any special fixing means for the contacts, such as insert molding or welding, making it possible to reduce costs and making the installation work extremely easy.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the main parts of the embodiment of the present invention, Fig. 2 is a front view and both side views of the contact of the embodiment of the invention, Fig. 3 is a perspective view of the contact, and Fig. 4 is the application of the present invention. The entire liquid level detection device that can be used is shown, a
5 is a plan view, b is a front view, c is a sectional view, FIG. 5 is a sectional view of a main part of a conventional device, and FIG. 6 is a sectional view of a main part of another conventional device. 4...Resistance plate, 4a, 4b...Resistor, 5...
Float, 5b...Groove, 8...Contact, 8a
...Free end, 8b...First bent part, 8c... Fitting part, 8d... Engaging claw.

Claims (1)

[Claim for Utility Model Registration] A resistor is inserted into a hole formed in the center, and a contact slides on the resistor as the float moves, thereby detecting changes in the liquid level as changes in electrical resistance. In the liquid level detection device, a groove of a predetermined width is formed on the upper surface of the float in the peripheral area of the hole, and a groove of a predetermined width is formed on the upper surface of the float at the end of the contact opposite to the side that contacts the resistor in the hole. A bent part is formed to follow the inner wall of the groove connected to the groove, and an elastic fitting is formed at the end of the bent part extending into the groove, which is bent outward in a V-shape. A locking pawl that bites into the inner wall is formed in the middle of the extension portion that forms a part and contacts an inner wall of the groove, the fitting portion is press-fitted into the groove, and the locking pawl A liquid level detection device characterized in that a contact is attached and fixed to a float by biting into the inner wall of a groove.