JP5523252B2 - Liquid level detector - Google Patents

Description

  The present invention relates to a liquid level detection device that is mounted on a fuel pump module that is held in an opening of a fuel tank that stores fuel and that sends the fuel out of the fuel tank, and detects a liquid level in the fuel tank. It is about.

  A conventional liquid level detection device includes a float that floats on a fuel level in a fuel tank, a float arm that is assembled with the float, an arm holder that holds the float arm and includes a bearing that is a pivotal fulcrum of the float arm, and an arm holder The upper and lower frames that pivotally support the bearings, the circuit board that is fixed to the frame, and the contacts that slide on the circuit board. The float moves up and down due to liquid level fluctuations in the fuel tank. Accordingly, the contact point slides on the circuit board via the float arm, and the liquid level in the fuel tank is detected by outputting a signal corresponding to the liquid level. (For example, see Patent Document 1)

Japanese Patent No. 3981858

  The liquid level detection device is assembled in a fuel pump module and arranged in a fuel tank, and it is required to improve the ease of assembly, improve the ease of insertion into the fuel tank by downsizing, and reduce the cost. .

  However, in the above-described conventional example, since the upper frame is provided, the height direction is thick, there is a limit to downsizing, the number of parts increases, and the upper frame and the lower frame are fixed. There are problems such as time-consuming manufacturing due to welding work.

  The present invention has been made to solve the above-described problems, and provides a low-priced liquid level detection device by improving the insertability into a fuel tank by downsizing and reducing the number of parts and work processes. Is what you do.

A liquid level detection device according to the present invention is provided in a fuel pump module for sending fuel out of a fuel tank, and detects a liquid level fluctuation in the fuel tank by a float floating on the liquid level in the fuel tank. In the detection device, the liquid level detection device includes an attachment member provided in the fuel pump module and provided with a liquid level detection device main body attachment guide in the vertical position , a frame front opening and a frame rear wall. A frame attached to the attachment member by a rail for holding the liquid level detection device inserted along the body attachment guide, an arm holder bearing support provided on the frame rear wall, and a support for the arm holder bearing An arm holder having a bearing portion supported by the arm portion, and the arm holder bearing portion support by the arm holder bearing portion. Parts together linked float arm to the float is attached pivotably around a, provided on the float arm, a movable contact which cooperates with the float arm in response to the liquid level fluctuation, sliding the movable contact is has a conductive pattern to a circuit board mounted on said frame, an electrical quantity of the circuit board upper Symbol movable contact is changed by sliding the conductive pattern, two lead wires to be sent to the outside, The lead wire is provided through a conductive spring having one end connected to one end of the lead wire and the other end connected to the movable contact, and a superposed portion formed when the circuit board is attached to the frame. a through-hole that the insert transmural, in the through hole portion, der those connected the conductive pattern and the above conductive springs respectively above each lead .

  According to the liquid level detection device of the present invention, the upper frame as in the conventional example is not required, and the lead wire is directly connected to the circuit board by inserting the lead wire from the through hole of the circuit board provided in the circuit board. , The terminal for connecting to the circuit board, and the terminal receiving part that holds the terminal can be abolished, the insertion into the fuel tank is improved by downsizing, the number of parts is reduced, and the work A liquid level detection device capable of reducing the number of processes can be provided.

It is an external appearance perspective view of the liquid level detection apparatus in Embodiment 1 of this invention. It is a disassembled perspective view of the liquid level detection apparatus in Embodiment 1 of this invention. It is the front view which looked at FIG. 2 in the arrow A direction. FIG. 4 is a rear view in FIG. 3. It is sectional drawing which looked at the VV line in FIG. 3 in the arrow direction. It is explanatory drawing at the time of attaching a liquid level detection apparatus to an attachment member, (a) is a state figure before attachment, (b) is a state figure after attachment.

Embodiments of the present invention will be described below with reference to the drawings.
In addition, the same code | symbol shows the same or an equivalent part between each figure.

Embodiment 1 FIG.
As shown in the drawing, the liquid level detection device in the first embodiment sandwiches the float arm 7 between the frame front opening 1c and the mounting member 10 disposed in the fuel pump module disposed in the fuel tank. The frame 1 is attached to the mounting member 10 with the back side of the frame back wall 1d exposed, and lead wires are inserted from the frame back wall 1d through the frame through hole and the circuit board through hole and directly into the circuit board 2. It is intended to be connected.

  In FIG. 1, the liquid level detection device is configured to be attached to an attachment member 10 disposed in a fuel tank (not shown), and the attachment member 10 is, for example, a sub tank that forms a fuel pump module (not shown). The attachment member 10 is a flat plate, but may be a curved surface.

The liquid level detection apparatus according to Embodiment 1 is configured as shown in FIGS.
That is, the liquid level detection device holds a float 8 floating on a fuel level in a fuel tank (not shown), a float arm 7 coupled (connected) to the float 8, and the float arm 7 and the float 8. A push nut 9 (FIG. 1), an arm holder 3 having a bearing portion 3a which is a pivot point of the float arm 7, and holding the float arm 7 in a swingable manner, and a bearing portion 3a of the arm holder 3 will be described later. A frame 1 that is supported (supported) by a supporting portion 1f for arm holder bearings, and a circuit that is fixed to the frame 1 as will be described later, and is provided with a conductive pattern 2c and circuit board through holes 2a and 2b. A substrate 2, a movable contact 4 that is in sliding contact with the circuit board 2, a conductive spring 5 for electrically connecting the movable contact 4 and the circuit board 2, and one end of the conductive spring And a conductive pattern 2c are connected to one end of the conductive pattern 2c as described later, and a change in the amount of electricity, for example, a change in electric current (electrical signal) caused by the movable contact 4 sliding on the circuit board 2 as the liquid level fluctuates. It is composed of lead wires 6a, 6b and the like for sending out to the terminal.

The frame 1 has a frame front opening 1c and a frame rear wall 1d, and a circuit board fitting recess 1e for incorporating (fitting) the circuit board 2 is formed in the frame rear wall 1d. Yes.
The frame back wall 1d adjacent to the circuit board fitting recess 1e is provided with an arm holder bearing support 1f that supports (supports) the bearing 3a. By press-fitting the bearing portion 3a into the support portion 1f, the float arm 7 is supported rotatably (swingable) around the arm holder bearing portion support portion 1f while being fixed in the axial direction.

Further, circuit board pressing portions 1g and 11g project from the frame front surface opening 1c to which the circuit board 2 is assembled. When the circuit board 2 is assembled to the frame 1, the circuit board pressing portion 1g and 11g project. Secure it so that it does not come off.
In addition, as will be described later, the frame 1 includes a lead wire holding portion 1h, liquid level detection device holding rails 1j and 11j, a conductive spring mounting shaft 1s, lead wire frame through holes 1a and 1b, and the like.

  In addition, the movable contact 4 assembled | attached to the arm holder 3 is assembled | attached to the back surface of the arm holder 3 which is not shown in figure, and is fixed to the arm holder 3 by heat welding, for example.

The conductive pattern 2 c , the movable contact 4 and the conductive spring 5 are connected as follows.
After the arm holder bearing portion 3a of the arm holder 3 is press-fitted into the arm holder bearing portion support portion 1f provided on the frame 1, and the arm holder 3 is freely fixed around the arm holder bearing portion support portion 1f, A conductive spring 5 for electrical conduction is connected in the vicinity of the arm holder bearing support 1f. At this time, one end 5a of the conductive spring 5 is connected to the movable contact 4 that slides on the circuit board 2, and the other end 5b is connected to the circuit board 2 as described later. 2b is inserted and temporarily fixed.

Next, connection and fixing of the lead wires 6a and 6b will be described.
Frame transmural hole 1a, 1b and the circuit board through-hole 2a, 2b, when attached crowded fitted superposing circuit board 2 on the circuit board fitting recess 1e of the frame 1, the overlapping portion as shown in FIG. 5 Are provided so as to penetrate both of them on the same axis.

The lead wire 6a is inserted from the frame through hole 1a into the circuit board through hole 2a, and the lead wire 6b is inserted from the frame through hole 1b into the circuit board through hole 2b. In FIG. 2, each of them is connected and fixed by solder.
That is, the lead wires 6a and 6b are inserted into the frame through holes 1a and 1b and the circuit board through holes 2a and 2b, and then connected to lead wires and conductive springs provided in a part of the circuit board 2. Electrode patterns Ta and Tb (configured by part of the electrode pattern instead of the terminal) are connected by solder. At this time, the other end 5b of the conductive spring 5 is inserted from the circuit board through hole side and soldered to the frame through hole 1b and the circuit board through hole 2b through which the lead wire 6b is inserted, simultaneously with the lead wire 6b.
That is, the lead wire 6a is inserted from the frame through hole 1a to the circuit board through hole 2a, and is connected and fixed by the connecting electrode pattern Ta by solder. The lead wire 6b is inserted into the circuit board through hole 2b from the frame through hole 1b. At the same time, the other end 5b of the conductive spring is inserted into the frame through hole 1b from the circuit board through hole 2b and then connected to the conductive pattern Tb for connection. The connection is fixed by soldering.

  By configuring as described above, the terminals for holding the lead wires 6a and 6b and connecting to the circuit board 2 can be eliminated, and the terminal receiving part for holding the terminals can be eliminated at the same time. Reduction of work processes and downsizing can be realized.

  Further, the soldering process of soldering the conductive spring 5 and the circuit board 2 and the soldering of the lead wires 6a and 6b and the circuit board 2 is not necessary, and the soldering process can be integrated at a time.

After the lead wires 6a and 6b are inserted from the back side of the frame rear wall portion 1d, the lead wires 6a and 6b are hooked and held on the lead wire holding portion 1h disposed on the frame 1, so that the lead wires 6a and 6b are liquid surfaces in the fuel tank. It is possible to prevent disconnection and film tearing caused by contact with other parts due to vibration caused by

  The configuration of the liquid level detection device according to the present invention is such that when the parts such as the circuit board 2 and the arm holder 3 are assembled from the frame front opening 1c and are attached to the attachment member 10 provided in the fuel pump module, the frame The front opening 1c comes into contact with the attachment member 10, and the back side of the frame rear wall 1d is exposed.

  The lead wire 6a, 6b connection structure of the liquid level detection device according to the present invention is possible because the liquid level detection device is attached to the mounting member 10 with the back side of the frame rear wall portion 1d exposed as described above. It has a configuration.

  One end of the float arm 7 that holds the float 8 is inserted into a through hole (not shown) provided in the float 8 that floats on the fuel level in the fuel tank, and is prevented from being detached by a push nut 9. The other end of the other end is press-fitted and fixed to an arm holder 3 that is rotatably attached to an arm holder bearing support 1f disposed on the frame 1, and the liquid level in the fuel tank is changed. The accompanying vertical movement of the float 8 is transmitted to the arm holder 3 via the float arm 7 and to the movable contact 4 assembled to the arm holder 3.

  In the liquid level detection apparatus configured as described above, the float 8 detects the liquid level height, is transmitted to the movable contact 4 via the float arm 7, and is brought into sliding contact with the circuit board 2, thereby The liquid level in the tank is converted into an electric signal, which is output to the outside through the conductive spring 5 and the lead wires 6a and 6b.

  Next, the operation of mounting the liquid level detection device configured as described above on the mounting member 10 provided in the fuel pump module (not shown) will be described with reference to FIG.

The liquid level detection device holding rails 1j and 11j respectively disposed on the upper and lower sides of the frame 1 are liquid level detection device main body mounting guides 10a disposed on the upper and lower positions of the mounting member 10, respectively.
Is inserted until it abuts against the abutting portion 10b disposed in the guide.

  When the liquid level detection device holding rails 1j and 11j are inserted along the liquid level detection device main body mounting guide guide 10a, the claw portions 1k and 11k provided on the frame 1 are provided on the guide 10a. It contacts the locking portion 10c and is inserted while being elastically deformed inside.

At the same time that the liquid level detection device holding rails 1j and 11j are brought into contact with the contact portion 10b, the claw portions 1k and 11k that are inserted while being elastically deformed pass through the inside of the locking portion 10c to return to the original shape. At the same time, the claw portions 1k and 11k and the locking portion 10c come into contact with each other and the frame 1 is prevented from coming off.

  As described above, according to the embodiment of the present invention, it is possible to reduce the manufacturing cost by improving the insertability to the fuel tank by reducing the size, reducing the number of parts and the work process, and providing a low-cost liquid level detection device. It becomes possible.

1 frame 1a, 1b frame through the lead wire hole 1c frame front opening 1d frame rear wall portion 1e circuit board fitting recess 1f arm holder bearing portion supporting portion 1 g, 11g circuit board holding unit 1h lead wire holding portion 1j, 11j liquid level detecting apparatus holding rail 1k, 11k claw portion 1s conductive spring mounting shaft 2 circuit board 2 c conductive patterns 2a, 2b the circuit board through-hole 3 arm holder 3a arm holder of the bearing portion 4 the movable contact 5 electrically conductive spring 5a, 5b conductive spring terminals 6 6a, 6b lead 7 float arm 8 float 9 push nut 10 attached member 10a liquid level detection device body mounting guide 10b abutting portion 10c locking portion.

Claims (3)

In a liquid level detection device that is equipped in a fuel pump module for sending fuel out of a fuel tank and detects a liquid level fluctuation in the fuel tank by a float that floats on the liquid level in the fuel tank,
An attachment member provided in the fuel pump module and provided with a liquid level detection device main body attachment guide at the vertical position , a frame front opening and a frame rear wall, and the liquid level detection device main body attachment guide A frame attached to the attachment member by a liquid level detection device holding rail inserted along, a support portion for the arm holder bearing portion provided on the back wall of the frame, and a support portion for the arm holder bearing portion. An arm holder having a bearing portion, a float arm that is swingably mounted around the support portion for the arm holder bearing portion by the bearing portion of the arm holder, and is connected to the float, and is provided in the float arm. A movable contact that cooperates with the float arm in response to the liquid level fluctuation, and a conductive material that slides the movable contact. Has a turn, the circuit board attached to said frame, an electrical quantity of the circuit board upper Symbol movable contact is changed by sliding the conductive pattern, two lead wires to be sent to the outside, the lead One end of the wire is connected to one end of the wire and the other end is connected to the movable contact, and the overlapping portion formed when the circuit board is attached to the frame is provided through the lead wire. A liquid level detection device comprising a through hole to be inserted, wherein the conductive pattern and the conductive spring are connected to the lead wires in the through hole portion, respectively.   2. The liquid level detection device according to claim 1, wherein an attachment surface side of the frame to which the float arm and the circuit board are attached is directly attached to the attachment member.   The liquid level detection device according to claim 2, wherein the frame is provided with a lead wire holding portion for holding the lead wire.

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