Liquid surface detection unit

Abstract

Liquid surface detection unit (2) with: a storage container (4); a body (20) attached to a side wall (4a) of the storage container (4); an arm (32) rotatably supported by the body (20); a sensor unit (40) housed in the body (20) and configured to detect a rotational movement of the arm (32); a connection unit (14) extending from the sensor unit (40); and a cable harness (12) connected to the connection unit (14) and extending to an outside of the body (20), wherein the body (20) has a groove (21) which surrounds and guides the cable harness (12) together with the side wall (4a) of the storage container (4), the cable harness (12) extending from the connection unit (14) to the outside of the body (20), the connection unit (14) has three connections (14a; 14b; 14c) which are arranged at a distance from one another, the body (20) has: Partition walls (24) each arranged in a space between a pair of adjacent terminals (14a; 14b; 14c) and extending from the side wall (4a) of the reservoir (4) to a side opposite the reservoir (4) beyond the terminals (14a; 14b; 14c); a connecting wall (22) extending in a direction crossing the partition walls (24) at a position separated from one end of the terminal unit (14) on a side opposite the sensor unit (40), connecting the partition walls (24) adjacent to each other, extending from the side wall (4a) of the reservoir (4) to the side opposite the reservoir (4) beyond the terminal unit (14), and having the groove (21), and the reservoir (4) has a projection (60) configured to be inserted into the groove (21) and to surround the cable harness (12) together with the groove (21).

Description

Technical area

[0001] The technique disclosed herein relates to a liquid surface detection unit configured to detect a liquid surface of a liquid (for example, a device configured to detect a liquid surface of a fuel stored in a fuel tank of a vehicle). Technical background

[0002] Japanese patent application publication number JP 2012-181106 A describes a liquid surface detection device comprising a body, an arm rotatably supported by the body, and a detection unit for detecting rotation of the arm. The detection unit is connected to an external device via three terminals and wiring harnesses connected to the terminals.

[0003] The body is attached to a side wall of a storage container. The body is provided with grooves in which the cable harnesses extending from a terminal unit extend. The ends of the grooves are closed on one side of the storage container, extend in a direction away from the storage container, and are open on a side opposite the storage container.

[0004] JP 2010 - 256 239 A, JP 2015 - 117 968 ​​A and JP 2016 - 57 099 A disclose further liquid level detection devices. SummaryTechnical problem

[0005] In a state where a liquid surface detection device is provided in a container, a wire harness may wobble relative to a body due to deformation of the container. As a result, if the wire harness is displaced within a groove in a direction away from a reservoir, a force is applied to a connection between the wire harness and a terminal unit, and there is a possibility that the wire harness may detach from the terminal unit.

[0006] The disclosure described herein provides a technique for preventing a wire harness in a groove from being displaced in a direction away from a reservoir. Solution to the technical problem

[0007] A liquid surface detection unit comprises: a reservoir; a body attached to a side wall of the reservoir; an arm rotatably supported by the body; a sensor unit housed in the body and configured to detect rotational movement of the arm; a terminal unit extending from the sensor unit; and a wiring harness connected to the terminal unit and extending to an exterior of the body. The body may have a groove surrounding the wiring harness and guiding it along the side wall of the reservoir, and the wiring harness may extend from the terminal unit to the exterior of the body.

[0008] According to the above configuration, the wire harness is surrounded by the groove of the body and the side wall of the reservoir. According to this structure, displacement of the wire harness can be limited. This prevents the wire harness from being displaced in the groove in a direction away from the reservoir. Since the wire harness is surrounded by the groove and the reservoir, no cover or the like needs to be additionally provided at an opening portion of the groove.

[0009] The terminal unit has three terminals arranged at intervals from each other. The body includes: partition walls, each arranged in a space between a pair of adjacent terminals and extending from the side wall of the reservoir toward a side opposite the reservoir beyond the terminals; and a connecting wall extending in a direction crossing the partition walls at a position spaced from an end of the terminal unit on a side opposite the sensor unit, connecting the partition walls adjacent to each other, extending from the side wall of the reservoir to the side opposite the reservoir beyond the terminal unit, and having the groove.Since the partition walls are arranged between the adjacent terminals, extending from the side wall of the reservoir toward the side opposite the reservoir beyond the terminals, electrical erosion of the terminals can be prevented when the terminal unit is immersed in a liquid in a container. Furthermore, the partition walls can be reinforced by the connecting wall, which can prevent the partition walls from breaking.

[0010] The terminal block can be exposed from the body. Electrical erosion can be prevented by the partition walls, even if the terminal block is exposed to the outside. This eliminates the need for a cover to protect the terminal block from electrical erosion. As a result, the connection status of the terminal block and the wiring harness can be easily checked during maintenance work, for example.

[0011] The reservoir has a projection configured to be inserted into the groove and to surround the wire harness together with the groove. According to this configuration, the wire harness can be constrained within the groove by the projection. As a result, the wire harness can be prevented from shifting within the groove in a direction away from the reservoir.

[0012] The body and the reservoir may each have an engagement portion. The engagement portions may be configured to engage with each other by sliding the body relative to the reservoir in an extending direction of the wire harness. The protrusion may have a height from the side wall of the reservoir, and the height may gradually increase along a direction in which the body is slid upon engagement of the engagement portions. According to this configuration, the protrusion can be smoothly inserted into the groove when the body is attached to the side wall of the reservoir by sliding it in a state where the wire harness is disposed in the groove. Short description of the drawings Fig. 1 shows a front view of a liquid surface detection unit according to an embodiment; Fig. 2 is a front view of the liquid surface detection unit according to the embodiment in a state where an arm and a rotary member are separated; Fig. 3 is a side view of the liquid surface detection unit according to the embodiment in a state where an arm and a rotary member are separated; Fig. 4 is a front view of a side wall of a storage container showing engagement areas and projections; Fig. 5 shows a side view of the projection; and Fig. 6 shows a plan view of the liquid surface detection unit according to the embodiment. Description of the embodiments

[0013] A liquid surface detection unit 2, which is in Fig. 1 is configured to detect a liquid surface of fuel in a fuel tank TK mounted on a vehicle, such as an automobile. The liquid surface detection unit 2 is arranged in the fuel tank TK.

[0014] The liquid surface detection unit 2 includes a reservoir 4 and a liquid surface detection device 10. The reservoir 4 houses a fuel pump (not shown). The fuel outside the reservoir 4 is supplied into the reservoir 4 by a jet pump using the fuel discharged from the fuel pump.

[0015] The liquid surface detection device 10 is attached to an outer surface of a side wall 4a of the reservoir 4. The liquid surface detection device comprises a body 20, a float 34, an arm 32, a rotary member 30, a sensor unit 40 (see Fig. 2), a terminal unit 14, and a wiring harness 12. The float 34 floats on the fuel in the fuel tank TK and is configured to move up and down following the liquid surface of the fuel. The float 34 is rotatably mounted on a distal end of the arm 32. A base end of the arm 32 is supported by the rotary member 30. The rotary member 30 is rotatably supported by the body 20. When the float 34 moves up or down following the liquid surface of the fuel in the fuel tank TK, the arm 32 swings and rotates with respect to the body 20. The arm 32 thus converts the up and down movement of the float 34 into a rotary movement.

[0016] The rotating member 30 is configured to rotate relative to the body 20 following the rotation of the arm 32. A permanent magnet is fixed to the rotating member 30. The permanent magnet is arranged such that a direction of the magnetic flux or an intensity of the magnetic flux changes according to the rotation of the rotating member 30.

[0017] As in Fig. As shown in Figure 2, the body 20 includes a guide rail 26 that guides the rotating member 30. The guide rail 26 has an annular or ring-shaped ring. The rotating member 30 is configured to rotate along the guide rail 26. The sensor unit 40 is housed within the body 20. The body 20 covers the sensor unit 40. The sensor unit 40 is arranged to face the permanent magnet of the rotating member 30.

[0018] The sensor unit 40 is configured to detect the rotational movement of the arm 32 by detecting a change in the direction of the magnetic flux or a change in the intensity of the magnetic flux of the permanent magnet of the rotating member 30. Based on the detection result, an analog signal corresponding to the amount of fuel stored in the fuel tank TK is output to a fuel meter (not shown). This sensor unit 40 includes a magnetic sensor configured to detect a rotation angle of the permanent magnet, i.e., a rotation angle of the arm 32. This sensor is a magnetic detection device, such as a known MRE (Magnetic Resistive Element) sensor or a Hall IC.

[0019] The connection unit 14 extends upward from the sensor unit 40. The connection unit 14 has an input terminal 14a, an output terminal 14c, and a ground terminal 14b. The three terminals 14a, 14b, and 14c each have a flat, plate-like shape.

[0020] Each of the wire harnesses 12 is connected to a corresponding one of the terminals 14a, 14b, 14c. Specifically, the wire harnesses 12 are fixed to the respective terminals 14a, 14b, 14c by riveting or welding them to the respective terminals 14a, 14b, 14c. The wire harnesses 12 extend in a Z direction from the terminal unit 14 toward an outside of the body 20. Each of the wire harnesses 12 includes a conductive wire and a resin cover covering the conductive wire.

[0021] Each of the terminals 14a, 14b, 14c is exposed to the outside of the body 20 at an area connected to its corresponding wire harness 12. This allows the connection status of the terminals 14a, 14b, 14c and the wire harnesses 12 to be easily checked. Other areas of the terminals 14a, 14b, 14c are covered by the body 20.

[0022] The body 20 has partition walls 24, each disposed between the terminals 14a and 14b, which are adjacent to each other, and between the terminals 14b and 14c, which are adjacent to each other. One of the partition walls 24 is located at a center between the terminals 14a and 14b. The terminals 14a and 14b, which are each located on either side of the partition wall 24 in the X direction, and is separated from both terminals 14a and 14b. The other of the partition walls 24 is located at a center between the terminals 14b and 14c, which are each provided on either side of the partition wall 24 in the X direction, and is separated from both terminals 14b and 14c. The partition walls 24 each have a flat plate-like shape. As shown in Fig. 3, each partition wall 24 extends in a Y-direction from an end face of the body 20 on one side of a side wall 4a to a position separated from the reservoir 4, beyond the connecting unit 14. In Fig. 3, the exposed area of ​​the terminal 14c is indicated by a dashed line.

[0023] The partition walls 24 extend in the Z direction along the terminals 14a, 14b, and 14c. One end of the partition walls 24 is arranged to be separated farther from the sensor unit 40 than ends of the terminals 14a, 14b, 14c on a side opposite the sensor unit 40, and other ends of the partition walls 24 extend closer to the sensor unit 40 than the exposed portions of the terminals 14a, 14b, 14c.

[0024] As in Fig. 2, the body 20 further includes a connecting wall 22 that connects one end of the two partition walls 24 in the Z direction. The connecting wall 22 has a flat, plate-like shape. The connecting wall 22 is arranged vertically with respect to the partition walls 24. The connecting wall 22 is arranged at one end of the body 20 on a side where the cable harnesses 12 are arranged. As shown in Fig. 3, the connecting wall 22 extends from the end surface of the body 20 on the side wall 4a side in the Y direction to a position separated in front of the reservoir 4, beyond the connecting unit 14. A distal edge of the connecting wall 22 in the Y direction is located on a same plane on which end edges of the partition walls 24 are located.

[0025] As in Fig. 2, the connecting wall 22 extends in the X-direction from above the connection 14a to above the connection 14c. As shown in Fig. 6, the connecting wall 22 has grooves 21 through which the three wire strands 12 pass. The grooves 21 each have a U-shape. The grooves 21 are open at one end of the body 20 on the side wall 4a side. A length of the grooves 21 in the X direction is slightly shorter than a diameter of the wire strands 12. The grooves 21 extend in the X direction from the end of the body 20 on the side wall 4a side to above the terminals 14a, 14b, 14c. According to this structure, the grooves 21 can guide the wire strands 12 extending straight from the terminals 14a, 14b, 14c through the bottoms and side surfaces of the grooves 21.

[0026] One end of the body 20 on one side of the reservoir 4 is in contact with the side wall 4a of the reservoir 4. The body 20 is thus directly attached to the side wall 4a of the reservoir 4, but not attached to the side wall 4a via an adapter or the like provided separately from the body 20 and the reservoir 4. As shown in Fig. As shown in Figure 2, the body 20 and the reservoir 4 are secured to each other by engagement mechanisms. The engagement mechanisms include engagement portions 27, 28, 52, 54. Specifically, the engagement portions 28 of the body 20 each protrude from both ends of the body 20 in the X direction. The engagement portions 27 are located at both ends of the body 20 in the X direction and at one end of the body 20 in the Z direction.

[0027] The engaging portions 54 of the reservoir 4 protrude from the side wall 4a toward one side of the body 20. The engaging portions 54 have spaces for receiving the engaging portions 28 between them and the side wall 4a. The engaging portions 54 have support plates that support the engaging portions 28, which are inserted into the spaces between them and the side wall 4a from a lower side in the Z direction. The engaging portions 54 of the reservoir 4 protrude from the side wall 4a toward the side of the body 20.

[0028] When the body 20 is to be attached to the storage container 4, the body is slid in the Z direction along the side wall 4a to insert the engaging portions 28 of the body into the spaces between the engaging portions 54 of the side wall 4a from above the engaging portions 54 of the storage container 4. As a result, the engaging portions 28 and the engaging portions 54 come into contact with each other. Further, the engaging portions 28 and the engaging portions 54 engage each other due to the engaging portions 54 of the storage container 4 abutting against the engaging portions 27 of the body 20 from above. The body 20 is thereby fixed to the storage container 4. In this state, the body 20 is supported from below by a support wall 56 projecting from the side wall 4a.

[0029] As in the Fig. 4 and Fig. 6, the projections 60 are provided on the side wall 4a at positions corresponding to the grooves 21. The projections 60 protrude from the side wall 4a toward the side of the body 20. The projections 60 extend in an extension direction of the cable strands 12, that is, in the Z direction. As shown in Fig. 5, the protrusions 60 have a length in the Y direction (i.e., a height from the side wall 4a) that gradually increases in a direction along which the body 20 is slid in the Z direction with respect to the reservoir 4, i.e., along the Z direction. When the body 20 is to be attached to the reservoir 4, the protrusions 60 are inserted into the grooves 21. As the body 20 is further slid with respect to the side wall 4a, the length of the protrusions 60 inserted into the grooves 21 becomes longer. As a result, spaces for the wire harnesses 12 in the grooves 21 gradually decrease as the body 20 is slid.

[0030] As in Fig. 6, in a state where the body 20 is fixed to the reservoir 4, each wire harness 12 is surrounded by the corresponding projection 60 and the groove 21. A space between the projection 60 and the groove 21 in the Y direction is slightly smaller than the diameter of the wire harness 12. As a result, the wire harness 12 can be properly held by the projection 60 and the groove 21. Furthermore, compared with a case where the projections 60 have a constant length in the Y direction, the wire harnesses 12 and the projections 60 can be prevented from interfering with each other while the body 20 is pushed, whereby the projections 60 can be smoothly inserted into the grooves 21.

[0031] In the liquid surface detection unit 2, the wire harnesses 12 are surrounded by the grooves 21 of the body 20 and the side wall 4a of the reservoir 4. According to this structure, displacement of the wire harnesses 12 can be prevented. This can prevent the wire harnesses 12 from shaking relative to the body 20 and from being displaced in the direction away from the reservoir 4. Furthermore, since the wire harnesses 12 are surrounded by the grooves 21 and the reservoir 4, a cover or the like does not need to be additionally provided on the upper portions of the grooves 21.

[0032] Since the partition walls 24 arranged between the adjacent terminals 14a, 14b, 14c extend from the side wall 4a of the reservoir 4 toward the side opposite the reservoir 4 beyond the terminals 14a, 14b, 14c, electrical erosion of the terminals 14a, 14b, 14c can be prevented when the terminal unit 14 is immersed in fuel. Therefore, no additional cover needs to be provided to protect the terminal unit 14 from electrical erosion.

[0033] Furthermore, the partition walls 24 can be reinforced by the connecting wall 22, whereby the partition walls 24 can be prevented from breaking. Although the connecting wall 22 is relatively long in the direction away from the side wall 4a, a distance to the side wall 4a from the positions where the terminal unit 14 and the wire harness 12 are connected does not change. Since the grooves 21 are open to the side wall 4a side, and the bottom ends of the grooves 21 are arranged at positions where the terminal unit 14 and the wire harnesses 12 are connected, the length of the grooves 21 in the Y direction does not need to be changed even though the connecting wall 22 is relatively long in the direction away from the side wall 4a. Compared with a case where the grooves 21 are open to a side opposite the side wall 4a in the connecting wall 22, the grooves 21 can be shortened.This allows the range of movement of the cable harnesses 12 within the grooves 21 to be reduced.

[0034] The wire harnesses 12 can be clamped within the grooves 21 by the projections 60. As a result, the wire harnesses 12 can be prevented from being displaced in the direction leading away from the reservoir 4 in the grooves 21.

[0035] Although specific examples of the present disclosure have been described in detail above, these examples are for illustrative purposes only and do not limit the scope of the claims. The technique described in the claims includes various changes and modifications of the specific examples described above. (1) Unlike the liquid surface detection device 10 configured to detect the amount of fuel in the fuel tank TK, the “liquid surface detection unit” disclosed here may be provided with, for example, a liquid surface detection device configured to detect a liquid surface in a water tank or in a water storage container (that is, a water level or a volume of stored water). (2) The liquid surface detection device 10 may be attached to an inner surface of the side wall 4a of the reservoir 4. (3) The reservoir 4 may be provided with projections 60. (4) The projections 60 may have a constant length in the Y direction along the Z direction. (5) The number of terminals 14a, 14b, 14c in the terminal unit 14 is not limited to three. The number of terminals can be appropriately determined depending on the type of sensor of the sensor unit. (6) The groove 21 and the side wall 4a may be spaced apart from each other. In this case, the distance between the end of the groove 21 on the side wall 4a side and the side wall 4a may be smaller than the diameter of the wire harness 12. This can prevent the wire harness 12 from being detached from the groove 21. This variation also includes the configuration that "the body has a groove that surrounds and guides the wire harness together with the side wall of the reservoir, the wire harness extending from the terminal unit to the outside of the body." (7) The length of the grooves 21 in the X direction may be equal to the diameter of the wire strands 12 or may be larger than the diameter of the wire strands 12. Further, a distance in the Y direction between the grooves 21 and the side wall 4a or the projections 60 may be equal to the diameter of the wire strands 12 or may be larger than the diameter of the wire strands 12.

[0036] The technical elements explained in the present description and drawings can be used either independently or in various combinations. The present disclosure is not limited to the combinations disclosed at the time of filing the claims. Furthermore, the purpose of the examples illustrated in the present description or in the drawings is to solve multiple problems simultaneously and to solve any one of these problems using technical means according to the present disclosure.

Claims

[1] Liquid surface detection unit (2) with: a storage container (4); a body (20) attached to a side wall (4a) of the storage container (4); an arm (32) rotatably supported by the body (20); a sensor unit (40) housed in the body (20) and configured to detect a rotational movement of the arm (32); a connection unit (14) extending from the sensor unit (40); and a cable harness (12) connected to the connection unit (14) and extending to an outside of the body (20), wherein the body (20) has a groove (21) which surrounds and guides the cable harness (12) together with the side wall (4a) of the storage container (4), the cable harness (12) extending from the connection unit (14) to the outside of the body (20), the connection unit (14) has three connections (14a; 14b; 14c) which are arranged at a distance from one another, the body (20) has: Partition walls (24) each arranged in a space between a pair of adjacent terminals (14a; 14b; 14c) and extending from the side wall (4a) of the reservoir (4) to a side opposite the reservoir (4) beyond the terminals (14a; 14b; 14c); a connecting wall (22) extending in a direction crossing the partition walls (24) at a position separated from one end of the terminal unit (14) on a side opposite the sensor unit (40), connecting the partition walls (24) adjacent to each other, extending from the side wall (4a) of the reservoir (4) to the side opposite the reservoir (4) beyond the terminal unit (14), and having the groove (21), and the reservoir (4) has a projection (60) configured to be inserted into the groove (21) and to surround the cable harness (12) together with the groove (21). [2] Liquid surface detection unit (2) according to claim 1, wherein the connection unit (14) is exposed from the body (20). [3] Liquid surface detection unit (2) according to claim 1 or 2, wherein the body (20) and the reservoir (4) each have an engagement portion (27; 28; 52; 54), the engagement portions (27; 28; 52; 54) are configured to engage with each other by sliding the body (20) relative to the reservoir (4) in an extension direction of the cable harness (12), and the projection (60) has a height from the side wall (4a) of the storage container (4), the height gradually increasing along a direction in which the body (20) is pushed upon engagement of the engagement portions (27; 28; 52; 54).

Images