WO2019065615A1

WO2019065615A1 - Liquid level detection device

Info

Publication number: WO2019065615A1
Application number: PCT/JP2018/035410
Authority: WO
Inventors: 明坂牧
Original assignee: 日本精機株式会社
Priority date: 2017-09-27
Filing date: 2018-09-25
Publication date: 2019-04-04
Also published as: JP7173025B2; JPWO2019065615A1

Abstract

In order to provide a liquid level detection device that does not cause degradation in detection accuracy or reliability, this liquid level detection device 1 is provided with: a rotating member 30 that rotates around a rotational axis O accompanying a change in the level of a liquid surface of a liquid; a supporting member 40 that rotatably supports the rotating member 30; a plurality of electrodes provided in the rotating member 30; and contact members 46 which are provided in the supporting member 40 and which come into sliding contact with an electrode among the plurality of electrodes in response to the rotation position of the rotating member 30. An inflow/outflow part 60 is provided on at least one of the rotating member 30 and the supporting member 40, and cleans by allowing the liquid to flow into a portion where the plurality of electrodes and the contact member 46 are in sliding contact, and thereafter flow out to the outside of the supporting member 40 and the rotating member 30.

Description

Liquid level detection device

The present invention relates to a liquid level detection device.

BACKGROUND ART Conventionally, a liquid level detection device that detects the height of the liquid level of a liquid stored in a container such as a fuel tank is known.
For example, in the liquid level detection device disclosed in Patent Document 1, a holder that rotates with the movement of the float following the change in height of the liquid surface, a frame that rotatably supports the holder, and the holder And a terminal provided on the frame and having a contact portion in sliding contact with any of the electrodes of the electrode portion in accordance with the rotational position of the holder. In this liquid level detection device, the liquid level is electrically detected from the change in resistance value due to the position where the electrode of the electrode part and the contact part of the terminal make sliding contact.

JP, 2014-139516, A

In the liquid level detection device disclosed in Patent Document 1, wear powder is generated because the electrodes of the electrode unit of the holder and the contact units of the terminals of the frame are in constant sliding contact, and the wear powder is on the electrodes and the contact unit. Depending on the type of liquid to be deposited, electrodes may be short-circuited, or sulfides may be generated depending on the type of liquid to be detected, and the volume of the sulfide may lead to a decrease in detection accuracy and reliability.

The present invention has been made in view of such circumstances, and it is an object of the present invention to provide a liquid level detection device which does not cause a decrease in detection accuracy and reliability.

In order to achieve the above object, the liquid level detection device of the present invention is
A pivoting member that pivots about a rotation axis with a change in the height of the liquid surface;
A support member rotatably supporting the rotating member;
A plurality of electrodes provided on the rotating member;
And a contact member provided on the support member and switched in sliding contact among the plurality of electrodes according to the rotation position of the rotation member,
The liquid is supplied to at least one of the rotating member and the supporting member, and the liquid is made to flow into a portion where the plurality of electrodes and the contact member make sliding contact, and the liquid is used as the supporting member and the rotating It has an inflow / outflow portion for flowing out to the outside of the member for cleaning.
It is characterized by

According to the present invention, it is possible to provide a liquid level detection device that does not cause a decrease in detection accuracy and reliability.

It is a schematic perspective view which concerns on one embodiment of the liquid level detection apparatus of this invention. It is the schematic perspective view explaining the contact state of the electrode and contact member which concern on one embodiment of this invention, and explanatory drawing of a circuit board. It is a schematic perspective view of the inversion state which concerns on one embodiment of this invention. It is a front view of only the frame part which concerns on one embodiment of this invention.

An embodiment of a liquid level detection device according to the present invention will be described with reference to the drawings.
As shown in FIGS. 1 and 2, the liquid level detection device 1 includes a float 10, a float arm 20, an arm holder (rotational member) 30, a frame (supporting member) 40, and a circuit board 50. Prepare. The circuit board 50 includes a plurality of

electrodes

51 and 52, and the frame 40 includes a contact member 46 sliding on and in contact with the

electrodes

51 and 52.

The float 10 is formed in a hollow shape by a synthetic resin so as to float on the liquid surface of a liquid in a fuel tank (not shown). The float 10 is displaced according to the level of the liquid level.

The float arm 20 is formed of metal in a rod shape, and rotates the arm holder 30 according to the position of the float 10.
The float arm 20 includes an L-shaped arm body 21 extending between the float 10 and the arm holder 30, a first bending portion 22 located at one end of the arm body 21 and to which the float 10 is attached, and an arm body And a second bent portion 23 positioned at the other end of the portion 21 and attached to the arm holder 30. The first bent portion 22 and the second bent portion 23 are formed to be bent at a right angle (direction orthogonal to the paper surface) with respect to the plane of the L-shaped arm main body 21. The second bending portion 23 constitutes a rotation axis O rotatably supported on the frame 40. In addition, the shape of the arm body 21 is not limited to the L shape depending on the attachment position of the liquid level detection device 1 to a fuel tank or the like, and is appropriately changed, and the shape can be displaced according to the change of the liquid level. Be done.

The arm holder 30 is an example of a pivoting member, and pivots with the float arm 20 with respect to the frame 40 about the rotation axis O while holding the float arm 20 as shown in FIGS. 1 to 3. The arm holder 30 is formed of a synthetic resin into a substantially base shape in which a substantially square and a substantially triangle are integrally combined.
The arm holder 30 includes a substantially triangular rotational support 31 and a substantially square main body 32. The main body 32 includes an inner substrate holding portion 33 and an outer arm holding portion 34. Prepare.

As shown in FIGS. 2 and 3, the pivoting support portion 31 is formed in a U shape so as to cover the apex portion of the triangle from the outside at a distance from the outer surface of the substantially triangle, and is U-shaped facing A bearing hole 31a is formed on the surface (inner side surface). A frame 40, which will be described later, is disposed between the opposing U-shaped portions of the rotation support portion 31, and the second bent portion 23 of the float arm 20 is inserted from the outside into the bearing hole 31a. The tip of the second bent portion 23 protrudes inside the support portion 31. A fixing fitting 31 b having a retaining function is provided at the tip of the second bent portion 23.
This prevents the arm holder 30 and the second bent portion 23 of the float arm 20 from being detached from the frame 40 located between the U-shaped portions of the rotation support portion 31.

As shown in FIG. 2, a substrate holding portion 33 is formed inside the rectangular main body portion 32 and is formed as a recess inside the arm holder 30, and a rectangular plate-like circuit substrate 50 is surrounded therearound. Hold. The substrate holding portion 33 is integrally formed with locking portions 33a that lock the three sides around the circuit board 50, and holds the circuit board 50 by bringing the remaining one side into contact with the recessed side wall surface.

As shown in FIG. 1, in the arm holding portion 34 on the outer side of the main body portion 32, the grip portion 34 a is disposed from the apex of the triangle of the rotation support portion 31 to the bottom side along the central portion of the main body portion 32. The grip portion 34 a is integrally formed with the main body portion 32 and grips the arm main body portion 21. The grip portion 34 a includes a cylindrical portion corresponding to the outer shape of the arm main body portion 21, and the side of the cylindrical portion is opened. Thus, by elastically deforming from the opening of the grip portion 34a, the arm body portion 21 is pushed in and mounted on the cylindrical portion, the float arm 20 is gripped by the arm holder 30, and the arm holder is integrated with the movement of the float arm 20. 30 rotates.

As shown in FIG. 2, a holder side stopper 35 for restricting the rotation range of the arm holder 30 is integrally formed on the main body 32, and the arm holder 30 is brought into contact with a stopper 43 of a frame 40 described later. Restrict the range of rotation of the The holder side stopper portion 35 utilizes a side wall portion which is formed so as to protrude to the inner side (frame 40 side, upward in FIG. 2) than the substrate holding portion 33, and from the rotation support portion 31 of the substantially square main body portion 32. The end face 35a of the far right (closer to the float 10) right angle part and the end face 35b of the groove provided at the right angle are used as stopper surfaces.

As shown in FIG. 3, the frame 40 includes a substantially square frame main body 41, and the frame main body 41 is formed with receiving recesses 45 on both sides of a partition that divides the front and back. An accommodation recess 45 a is formed on the front side of the frame main body portion 41 (the side facing the arm holder 30). A pair of contact members 46 is housed in the housing recess 45b on the back side. Further, in the frame 40, in the state where the arm holder 30 is mounted, the contact member 46 in the housing recess 45b of the frame 40 and the substrate holding portion 33 of the arm holder 30 rotatably attached to the frame 40 face each other. Are arranged to As a result, the contact member 46 and the plurality of

electrodes

51 and 52 of the circuit board 50 can be in sliding contact with each other.

The bearing portion 42 is for rotatably supporting the arm holder 30, and is formed at a position projecting to the side of the frame main body portion 41. The bearing portion 42 has a through hole, and is mounted between the U-shaped rotational support portions 31 of the arm holder 30, and the second bent portion of the float arm 20 from the outside of the rotational support portion 31 of the arm holder 30. 23 is inserted as the rotation axis O. Thus, the arm holder 30 is supported rotatably on the rotation axis O with respect to the frame 40.

The pair of contact members 46 extend parallel to the plurality of electrodes 51 and 52 (see FIG. 2B) of the circuit board 50 held by the substrate holding portion 33 of the arm holder 30, as shown in FIG. Are arranged. Each contact member 46 is formed in a substantially comb shape by a conductor, for example, nickel silver. For example, the pair of contact members 46 are insert-molded into the synthetic resin that constitutes the frame 40.
Each contact point member 46 includes a contact point 46a which contacts any one of the plurality of

electrodes

51 and 52 of the circuit board 50 according to the turning position of the arm holder 30, and a terminal portion 46b to which the wiring cord 47 is connected. Prepare. The contact 46a is located on one end side (inner side of the liquid level detection device 1) of each contact member 46 closer to the arm holder 30 side, and the terminal 46b is the other end side of each contact member 46 farther from the arm holder 30 (liquid level detection Outside the device 1). When the arm holder 30 rotates with respect to the frame 40, the electrode 51 which is in contact with the contact point 46a among the plurality of electrodes 51 on the circuit board 50 is switched.
The terminal 46 b is connected to an external device (not shown) via the wiring cord 47.
Thus, the liquid level detection device 1 outputs an output signal corresponding to the position of the float 10 to the external device through the wiring cord 47 connected to the terminal portion 46b. The external device receives this output signal and recognizes the position of the float 10, that is, the height of the liquid level.

As shown in FIG. 1 and FIG. 3, the stopper portion 43 on the frame 40 side contacts the end surface 35 a of the holder side stopper portion 35 of the arm holder 30 and the end surface 35 b of the groove so that the rotation range of the arm holder 30 Regulate.
The stopper portions 43 are arranged at two places separated from the side wall portion of the frame main body portion 41 by a predetermined angle with the rotation axis O as a center. Each stopper portion 43 has stopper surfaces 43a with which the end surfaces 35a and 35b on both sides of the holder-side stopper portion 35 are in contact.

The stopper portion 43 includes a separation preventing portion 43b that prevents the arm holder 30 from being separated when it exceeds an allowable rotation range (rotational angle) regulated by the stopper surfaces 43a on both sides. The detachment preventing portion 43b is formed to protrude at the outer end of each stopper surface 43a, and the rotation is restricted by applying the holder side stopper portion 35 which is rotated beyond the rotation range, and the arm holder 30 gets over. Prevent leaving.

The mounting portion 44 is disposed so as to protrude from the front side to the back side of the frame 40, and is for mounting to a mounting target (not shown) (for example, a fuel pump module in a fuel tank). Thus, the liquid level detection device 1 can be fixed to a mounting plate (not shown) provided on the mounting target via the frame 40.
The mounting portion 44 has three hook portions 44 a provided on the left and right sides and the tip end side (float 10 side) of the frame 40, and the tip end side and the base end side projecting from the center portion of the frame 40 (float 10 opposite to the tip end side) And two positioning portions 44b). The hook portion 44a is formed with a locking claw toward the outside, and is locked to a mounting plate fixed to the mounting object. The positioning portion 44b on the tip end side is disposed in the vicinity of the contact 46a of the contact member 46, and an inflow / outflow portion 60 described later is formed in the positioning portion 44b. Thus, the positioning is performed by the two positioning portions 44b, and the hooks 44a on the both sides intersecting with this and the hook portions 44a on the tip side are locked to the mounting plate fixed to the attachment object (not shown). It can be fixed in position.

As shown in FIG. 2, the circuit board 50 is made of a hard printed board and formed in a rectangular plate shape. The circuit board 50 is fixed to the rear surface of the arm holder 30 by the locking portion 33 a of the substrate holding portion 33 of the arm holder 30 described above. A plurality of

electrodes

51 and 52 are formed on the rear surface of the circuit board 50, and a resistor 53 is electrically connected to the plurality of

electrodes

51 and 52. Thereby, the electrode 51 which the contact 46a of the contact member 46 contacts among the plurality of electrodes 51 is switched according to the rotational position of the arm holder 30 with respect to the frame 40.

In the liquid level detection device 1, an inflow / outflow portion 60 of the liquid whose liquid level is to be detected is provided on at least one of the arm holder (rotational member) 30 and the frame (support member) 40 (FIG. 2 and FIG. 3). reference). The inflow / outflow portion 60 allows the liquid to flow into a portion where the plurality of

electrodes

51, 52 and the contact member 46 make sliding contact, and then the liquid is carried out outside the frame (supporting member) 40 and the arm holder (rotating member) 30. By flowing out and cleaning, it is for improving the reliability of the electrical connection by the sulfide etc. which are produced | generated by wear powder or liquid.
As shown in FIGS. 2 and 3, the inflow / outflow portion 60 is a side wall surface facing the frame 40 of the arm holder 30, a side wall surface facing the arm holder 30 of the frame 40, and a partition that divides the middle portion of the frame 40. Form on the surface.
Further, the inflow / outflow portion 60 may be provided in the positioning portion 44b so as to communicate with the portion where the plurality of

electrodes

51, 52 and the contact member 46 are in sliding contact.
By doing this, since the plurality of

electrodes

51, 52 and the contact member 46 are close to a sliding contact portion, the inflow of the inflowing liquid can be increased, and the deposition of wear powder and the like can be more effectively suppressed. it can.
Further, the inflow / outflow portion 60 is not limited to the case where it is constituted by a plurality of grooves shown in the drawing, for example, and may be formed as a hole or a groove and a hole may be combined. Mold formation can be facilitated.

In the liquid level detection device 1 configured as described above, detection of the liquid level is performed as follows.
The liquid level detection device 1 is fixed by the mounting portion 44 of the frame 40 via a mounting plate (not shown) in a state where it can be immersed in the liquid in the fuel tank (not shown).
The float 10 is displaced by displacement of the level of the liquid in the fuel tank. The displacement of the float 10 causes the arm holder 30 to pivot via the float arm 20.
Then, the electrode 51 to which the contact 46a contacts among the one of the plurality of electrodes 51 on the circuit board 50 is switched, and an output signal according to the position of the float 10 is connected to the external device through the wiring cord 47 connected to the terminal portion 46b. Output to
The external device receives this output signal and recognizes the position of the float 10, that is, the height of the liquid level.
When the position of such a float 10 is displaced, sliding contact occurs between the plurality of

electrodes

51 and 52 of the circuit board 50 of the substrate holding portion 33 of the arm holder 30 and the contact member 46 of the frame 40. Occurs and deposits. Also, depending on the type of fuel in the sliding contact portion, sulfide may be formed and deposited. The sliding contact is similarly caused not only by displacement of the liquid surface but also by vibration or the like from a vehicle or the like applied to the float 10.
On the other hand, in the liquid level detection device 1, at least one of the arm holder (turning member) 30 and the frame (support member) 40 is provided with the inflow / outflow portion 60 of the liquid whose liquid level is to be detected. The liquid is made to flow into a portion where the

electrodes

51 and 52 and the contact member 46 make sliding contact, and then the liquid is made to flow out of the frame (supporting member) 40 and the arm holder (rotating member) 30.
As a result, it is possible to wash away sulfides and the like generated by wear powder and liquid and allow them to flow out to the outside of the arm holder 30 and the frame 40, and it is possible to suppress the influence on the electrical connection by the deposits.
Therefore, it is possible to provide the liquid level detection device 1 which does not cause a decrease in detection accuracy and reliability.

Further, by forming the inflow / outflow portion 60 in the positioning portion 44b of the mounting portion 44 near the portion where the plurality of

electrodes

51, 52 and the contact member 46 make sliding contact, liquid flowing into the sliding contact portion The amount can be increased, the deposition of wear powder and sulfide can be more efficiently prevented, and the liquid level detection device 1 can be made high in detection accuracy and reliability.

Further, the inflow / outflow portion 60 can be constituted by a groove and / or a hole (a combination of a groove and a hole, only a groove, or only a hole), and can be formed by molding of a synthetic resin. When configured, mold design is facilitated.
By providing the inflow / outflow portion 60 with such grooves and / or holes, it is possible to easily make the liquid flow into the sliding contact portion and prevent the deposition of wear powder and sulfide, so that the detection accuracy A highly reliable liquid level detection device 1 can be provided.

As described above, according to the embodiment, as specifically described, according to the liquid level detection device 1 of the present invention, an arm holder (which pivots about the rotation axis O with a change in the liquid level of the liquid) A rotating member) 30, a frame (supporting member) 40 rotatably supporting the arm holder 30, a plurality of

electrodes

51 and 52 provided on the arm holder 30, and the frame 40, the rotation of the arm holder 30 And a contact member 46 in which the electrode 51 in sliding contact is switched among the plurality of

electrodes

51 and 52 according to the movement position, provided on at least one of the arm holder 30 and the frame 40 The inflow / outflow portion 60 includes the inflow / outflow portion 60 for flowing out the liquid to the outside of the frame 40 and the arm holder 30 for cleaning after flowing the liquid into the portion in sliding contact with the contact member 46. Et in the incoming liquid is generated by the abrasion powder or liquid can be washed away and sulfides, can be discharged from the output portion 60 flows to the outside of the arm holder 30 and frame 40 to wash wear powder and sulfides. In addition, wear powder and sulfide remaining in the fuel tank are separated by a filter, and mixing in the fuel gauge is prevented.
Thereby, the influence on the electrical connection by the deposit can be removed, and detection accuracy and reliability can be improved.

According to the liquid level detection device 1 of the present invention, the frame (support member) 40 is provided with the positioning portion 44b positioned in the mounting target portion, and the positioning portion 44b includes the plurality of

electrodes

51, 52 and the contact member 46. Since the inflow / outflow portion 60 is provided in communication with the slidingly contacting portion, the inflow / outflow portion 60 is formed in the positioning portion 44 b close to the portion where the plurality of

electrodes

51 and 52 and the contact member 46 slidingly contact. It is possible to increase the amount of liquid flowing into the sliding contact portion.
Thereby, deposition of wear powder and sulfide can be prevented more efficiently, and the liquid level detection device 1 can be made high in detection accuracy and reliability.

According to the liquid level detection device 1 of the present invention, the inflow / outflow portion 60 is made up of a plurality of grooves and / or holes, thereby allowing the liquid to easily flow into the portion that comes in sliding contact, resulting in wear powder or It is possible to prevent the deposition of sulfides, and in particular, in the case of forming by grooves, mold design is facilitated.

In addition, the liquid level detection apparatus 1 of this invention is not limited to the said embodiment, You may make it change this suitably and to implement.

In the above embodiment, the inflow / outflow portion 60 is formed on the side wall surface where the arm holder 30 and the frame 40 face each other. However, the present invention is not limited to this. The inflow penetrating in the front and back direction of the arm holder 30 or the frame 40 The protrusion 60 may be formed as long as the liquid can be made to flow into and out of the portion where the plurality of

electrodes

51, 52 and the contact member 46 slide.
Further, by forming the inflow / outflow portion 60 on a mounting plate (not shown) for attaching the liquid level detection device 1, the liquid is caused to flow into the portion where the plurality of

electrodes

51, 52 and the contact member 46 slide, and then flowed out. It can also be made to wash.
Furthermore, at least one inflow / outflow portion 60 may be formed, and the formation position may be only the arm holder 30, only the frame 40, or only the positioning portion 44b, or in the case where a plurality of formation positions are formed You may make it form.

DESCRIPTION OF SYMBOLS 1 Liquid level detection apparatus 10 Float 20 Float arm 21 Arm main-body part 22 1st bending part 23 2nd bending part 30 Arm holder (rotation member)
Reference Signs List 31 rotation support portion

31a bearing hole

31b fixing bracket 32 main body portion 33 substrate holding portion 33a locking portion 34 arm holding portion 34a holding portion 35 holder side stopper portion 35a end surface 35b end surface of groove portion 40 frame (supporting member)
41 frame body portion 42 bearing portion 43 stopper portion 43a stopper surface 43b detachment preventing portion 44 attachment portion 44a hook portion 44b positioning portion 45 accommodation recess 45a front side accommodation recess 45b back side accommodation recess 46 contact member 46a contact 46b terminal portion 47 wiring cord 50 circuit board 51 electrode 52 electrode 53 resistor 60 inflow / outflow portion O rotation shaft

Claims

A pivoting member that pivots about a rotation axis with a change in the height of the liquid surface;
A support member rotatably supporting the rotating member;
A plurality of electrodes provided on the rotating member;
And a contact member provided on the support member and switched in sliding contact among the plurality of electrodes according to the rotation position of the rotation member,
The liquid is supplied to at least one of the rotating member and the supporting member, and the liquid is made to flow into a portion where the plurality of electrodes and the contact member make sliding contact, and the liquid is used as the supporting member and the rotating It has an inflow / outflow portion for flowing out to the outside of the member for cleaning.
Liquid level detection device characterized by.
The support member includes a positioning unit that positions the mounting target unit.
The positioning portion is provided with the inflow / outflow portion in communication with a portion where the plurality of electrodes and the contact member make sliding contact.
The liquid level detection device according to claim 1, characterized in that:
The inflow / outflow portion is composed of a plurality of grooves and / or holes.
The liquid level detection device according to claim 1 or 2, characterized in that: