JP2019027793A - Liquid level detection device - Google Patents

Abstract

To provide a liquid level detection device with high reliability in wiring.SOLUTION: A liquid level detection device F includes: a holder 2 for rotating a circuit board 4 with a movement of a float FL to be operated by following a liquid level; terminals 5 each of which is equipped with an elastic piece 5D having a contact point 5A to be in contact with an electrode part 4A of the circuit board 4; a frame 1 incorporating a part of the terminals 5; and wiring 6 to be electrically connected to the terminals 5. A lock part 13A1 of the wiring 6 is arranged in a fixing part 13A for fixing the liquid level detection device F to an attachment member A.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a liquid level detection device for detecting the level of fuel in a fuel tank of an automobile.

  A conventional liquid level detection device is disclosed in Patent Document 1, for example. The liquid level detection device includes a holder that rotates the circuit board in accordance with the movement of the float that operates following the liquid level, a terminal that includes an elastic piece that includes a contact part that contacts the electrode part of the circuit board, In a liquid level detection device comprising a frame incorporating a part of the terminal, a wiring cord connected to the terminal is electrically connected by crimping, and the liquid level is detected by detecting a change in resistance value. Is.

JP 2014-139516 A

  However, since such a liquid level detection device has a high degree of freedom in routing the wiring cord, there is a possibility of inappropriate routing when being fixed to a fuel tank or the like, thereby improving the connection reliability of the wiring. There was room for improvement.

  The present invention pays attention to the above-described problems, and provides a liquid level detection device with high wiring connection reliability.

The liquid level detection device F of the present invention is
A holder 2 for rotating the circuit board 4 in accordance with the movement of the float FL that operates following the liquid surface;
A terminal 5 having an elastic piece 5D provided with a contact 5A in contact with the electrode portion 4A of the circuit board 4;
A frame 1 containing a part of the terminal 5;
A wiring 6 electrically connected to the terminal 5;
With
The fixing portion 13A for fixing the liquid level detection device F is provided with a locking portion 13A1 for the wiring 6.

The frame 1 is provided with a mounting surface 15A on which the wiring 6 is mounted.

  An inclined surface 15B that guides the wiring 6 to the mounting surface 15A is provided toward the mounting surface 15A.

  The liquid level detection device of the present invention has high wiring connection reliability.

The perspective view of the liquid level detection apparatus of one Embodiment of this invention. The front view of the liquid level detection apparatus of the embodiment. The figure which attached the liquid level detection apparatus of the embodiment to the attachment member. The front view of the flame | frame of the embodiment. The rear view of the flame | frame of the embodiment. The perspective view of the holder of the embodiment. The perspective view which looked at the holder of the embodiment from the back. The figure before attaching the wiring cord of the embodiment to a latching | locking part. The figure which attached the wiring cord of the embodiment to the latching | locking part.

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

  As shown in FIGS. 1, 2, and 3, the liquid level detection device F of the present invention includes a frame 1, a holder 2, a float arm 3, a circuit board 4, terminals 5, and a wiring cord (wiring). 6 and is used as a liquid level detection device for detecting the liquid level of various liquids in a tank of an automobile, motorcycle or the like. The liquid level detection device F is fixed to an attachment member A such as a fuel pump or an attachment stay made of synthetic resin or the like.

  The frame 1 is made of synthetic resin, for example, polyacetal, and integrally includes a base portion 11, a stopper 12, a hook portion 13, a bearing portion 14, and a locking portion 15, as shown in FIGS. ing. Further, a part of the terminal 5 is built in the frame 1 by insert molding.

  The base part 11 has three rectangular openings 11A, 11B, and 11C. Each opening 11 </ b> A, 11 </ b> B, 11 </ b> C penetrates the holder 2 in the rotation axis direction. In the first and second openings 11A and 11B, the crimped portion 5B of the terminal 5 is exposed, and in the third opening 11C, the contact 5A of the terminal 5 is exposed. The base 11 has a wall surface 11D at the end on the opening 11A, 11B side. The wall surface 11D includes a slit 11E, and the wiring cord 6 is drawn out of the frame 1 from the slit 11E.

  The stopper 12 is composed of a first stopper 12A and a second stopper 12B. As shown in FIGS. 4 and 5, the rotation angle of the holder 2, that is, the float, between the first and second stoppers 12A and 12B. The operating range of the arm 3 is defined.

  The hook part 13 is provided with three parts, a first hook part (fixed part) 13A and second hook parts 13B and 13B, and is engaged with an attachment member A such as a fuel pump or an attachment stay. 13 A of 1st hook parts are provided in the edge part on the opposite side to wall surface 11D of the flame | frame 1 where the wiring cord 6 is pulled out, and are provided with latching | locking part 13A1. The second hook portions 13B and 13B are provided on the side surface of the frame 1.

  The bearing portion 14 is provided on the outer peripheral portion of the frame 1, and includes a through hole 14 </ b> A through which the shaft portion 3 </ b> A of the float arm 3 is inserted and rotatably supported, and the holder 2 is rotatably supported. .

  The locking portion 15 is provided on a surface opposite to the surface in the direction in which the float arm 3 to be described later is inserted into the frame 1, and includes a mounting surface 15A and an inclined surface 15B inclined toward the mounting surface 15A. ing.

  The holder 2 rotates the circuit board 4 in accordance with the movement of the float that operates following the liquid level. The holder 2 is made of synthetic resin, for example, polyacetal resin. As shown in FIGS. 6 and 7, the plate-shaped upper piece 2A, the lower piece 2B facing the upper piece 2A, the upper piece 2A, and the lower piece 2B. And 2C of connection parts which connect.

  The upper piece 2A includes a substrate housing portion 2A0 for arranging the circuit board 4, first and second engaging portions 2D1 and 2D2 for holding the float arm 3, and the float arm 3 having first and second engaging portions. A retaining portion 2D3 that prevents the portions 2D1 and 2D2 from coming off, a contact portion 2E that contacts the stopper 12 of the frame 1, and an insertion portion 2F that includes a through hole through which the shaft portion 3A of the float arm 3 is inserted. It is equipped with.

  The substrate housing part 2A0 is arranged so that the electrode part 4A formed on the circuit board 4 is exposed on the surface. The board housing portion 2A0 includes two hooks 2A1 that come into contact with two orthogonal sides 4B of the circuit board 4. In addition, the substrate storage portion 2A0 includes two opposing portions 2A2 that face two opposite sides 4B of the circuit board 4 with which the two hooks 2A1 abut (opposite sides of the two sides 4B) and face two sides 4C. . In addition, the opposing portion 2A2 is provided with a plurality of positioning portions 2A3 that come into contact with the circuit board 4. Further, the board housing part 2A0 is provided with a movement blocking part 2A4 for blocking the movement in the vertical direction with respect to the plate surface direction of the circuit board 4.

  Each hook 2 </ b> A <b> 1 stops the movement in the vertical direction with respect to the plate surface direction of the circuit board 4 by locking the outer peripheral portion of the circuit board 4. Each hook 2A1 includes an elastic portion 2A11, and the elastic portion 2A11 presses the circuit board 4 against the opposing portion 2A2 side of the substrate storage portion 2A0 by the elastic force.

  Two positioning portions 2A3 are provided in each facing portion 2A2. The facing portion 2A2 has a semi-cylindrical shape and protrudes from each facing portion 2A2 in a direction parallel to the plate surface direction of the circuit board 4 stored in the substrate storage portion 2A0. The cross-sectional shape (the cross-sectional shape in the direction parallel to the plate surface direction of the circuit board 4) is an arc shape, and the contact area with the side 4C of the circuit board 4 can be suppressed. By providing this positioning part 2A3, there are many parts in contact between the side 4C of the circuit board 4 and the facing part 2A2 of the board storage part 2A0, and it is difficult to determine the position of the circuit board 4 with respect to the holder 2. By providing the portion 2A3, it is possible to easily position the circuit board 4 with respect to the holder 2 by minimizing the contact portion with the circuit board 4.

  In the present embodiment, two movement blocking units 2A4 are provided. One is between the two opposing portions 2A2, and the other is provided only in the opposing portion 2A2. In the present embodiment, the movement preventing portion 2A4 has a flat plate shape and projects in a direction parallel to the plate surface direction of the circuit board 4 accommodated in the substrate accommodating portion 2A0 from the facing portion 2A2. In the present embodiment, the movement prevention unit 2A4 is provided at a position corresponding to the two corners of the circuit board 4. The movement blocking unit 2A4 and the circuit board 4 may be in contact with each other, or may have a slight gap in consideration of a tolerance when the circuit board 4 is arranged in the board storage unit 2A0. By providing the movement preventing portion 2A4, it is possible to prevent movement in the vertical direction with respect to the plate surface direction of the circuit board 4. In the present embodiment, two movement blocking units 2A4 are provided, but the number of movement blocking units 2A4 may be one. Further, the position where the movement preventing portion 2A4 is provided may be the side 4C of the circuit board 4 instead of the corner of the circuit board 4.

  The lower piece 2 </ b> B includes an insertion portion 2 </ b> B <b> 1 including a through hole through which the shaft portion 3 </ b> A of the float arm 3 is inserted.

  The connecting portion 2C connects the upper piece 2A and the lower piece 2B. The insertion part 2F of the upper piece 2A and the insertion part 2B1 of the lower piece 2B are connected.

  The bearing portion 14 of the frame 1 is sandwiched between the upper piece 2A and the lower piece 2B. The bearing portion 14 is sandwiched between the insertion portion 2F of the upper piece 2A and the insertion portion 2B1 of the lower piece 2B.

  The float arm 3 is made of a hard steel wire, and as shown in FIGS. 1 and 2, the float arm 3 is bent into a predetermined shape so as to be attached to the holder 2 or matched to the fuel tank shape. A float FL is fixed to one end of the float arm 3. The float FL is made of NBR / phenol foam, floats on the liquid level of the fuel, etc., and operates following the liquid level. Further, a shaft portion 3A is provided at the other end. The shaft portion 3A passes through the through-hole 14A of the bearing portion 14 of the frame 1 and the two insertion portions 2F and 2B1 of the holder 2, so that the holder 2 is rotated about the shaft portion 3A of the float arm 3 as a rotation center. The frame 1 is supported so as to be rotatable.

  As shown in FIG. 7, the circuit board 4 includes an electrode portion 4 </ b> A, and a conductive material and a resistance material constituting the electrode portion 4 </ b> A are formed on the insulating substrate by printing and baking. The circuit board 4 is attached to the holder 2 and interlocks with a float that operates following the liquid level.

  The terminal 5 is made of, for example, a white material, and two terminals 5 are provided as shown in FIG. Each terminal 5 has an elastic piece 5D provided with a contact 5A that contacts the electrode part 4A of the circuit board 4, a crimping part 5B that holds the wiring cord 6, and a relay that connects the elastic piece 5D and the crimping part 5B. The unit 5C is integrally provided.

  The contact 5A is made of, for example, an alloy of palladium and nickel that contacts the electrode portion 4A of the circuit board 4 and slides on the electrode portion 4A. The elastic piece 5 </ b> D is formed such that the contact 5 </ b> A protrudes from the surface on the holder 2 side of the frame 1, and the contact 5 </ b> A is in contact with the circuit board 4.

  As shown in FIGS. 4 and 5, the wiring cord 6 includes two lines, a ground line and an output signal line, and is fixed to the terminal 5 by caulking.

  The procedure for assembling the wiring cord 6 to the frame 1 is as follows (before and after assembly are shown in FIGS. 8 and 9). First, the wiring cord 6 is assembled so as to pass through the slit 11E of the frame 1. Next, the wiring cord 6 is bent toward the locking portion 15, guided along the inclined surface 15 </ b> B of the locking portion 15, and fixed to the placement surface 15 </ b> A. Further, the wiring cord 6 is locked to the locking portion 13A1 by light press fitting or the like. At this time, as shown in FIG. 3, an attachment member A may be interposed between the frame 1 and the wiring cord 6. The mounting member A is preferably provided with a hole through which the mounting surface 15A and the locking portion 13A1 are exposed.

  With the above configuration, the wiring cord 6 is appropriately fixed and a desired retaining strength is obtained, so that a highly reliable connection structure is obtained.

  Therefore, it is possible to provide a liquid level detection device with high connection reliability of the wiring cord and good productivity.

  The above description exemplifies the present invention, and it goes without saying that various changes and modifications can be made without departing from the scope of the invention.

  The present invention is applicable to a liquid level detection device that detects the liquid level of various liquids in a tank.

F Liquid level detector FL Float 1 Frame 2 Holder 2A Upper piece 2A0 Substrate storage part 2A1 Hook part 2A11 Elastic part 2A2 Opposing part 2A3 Positioning part 2A4 Movement prevention part 2B Lower piece 2B1 Insertion part 2C Connection part 3 Float arm 3A Shaft part 4 Circuit board 4A Electrode part 4B Side 4C Side 5 Terminal 5A Contact 5B Clamping part 5C Relay part 5D Elastic piece 6 Wiring cord (wiring)
DESCRIPTION OF SYMBOLS 11 Base part 11A 1st opening part 11B 2nd opening part 11C 3rd opening part 11D Wall surface 11E Slit 12 Stopper 12A 1st stopper 12B 2nd stopper 13 Hook part 13A 1st hook part (fixing part)
13B 2nd hook part 14 Bearing part 14A Protrusion part 15 Locking part 15A Mounting surface 15B Inclined surface A Mounting member

Claims (3)

A holder that rotates the circuit board in accordance with the movement of the float that follows the liquid surface;
A terminal having an elastic piece with a contact point in contact with the electrode part of the circuit board;
A frame containing a part of the terminal;
Wiring electrically connected to the terminals;
In a liquid level detection device comprising:
The liquid level detection device according to claim 1, wherein a locking portion for the wiring is provided in a fixing portion for fixing the liquid level detection device. The liquid level detection device according to claim 1, wherein a mounting surface for mounting the wiring is provided on the frame. The liquid level detection device according to claim 2, wherein an inclined surface that guides the wiring to the mounting surface is provided toward the mounting surface.

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