Liquid level detection device

Abstract

A liquid level sensing device (10) for sensing a liquid level of a liquid stored in a tank, and a mounting object element (50, 50A) comprising the liquid level sensing device (10): a device main body (20, 20A) mounted on a mounting surface (51) of the mounting object element (50, 50A); and a holder (70) which is attached to the main body of the device (20, 20A) and is rotated according to a variation in the liquid level of the liquid stored in the tank, wherein the mounting object element (50, 50A) has a pair of locking sections (53) which lock respective side sections of the device main body (20, 20A) when the device main body (20, 20A) is inserted between the locking sections (53), and a pair of projections (56) which are configured to face a front section of the device main body (20, 20A) when the device main body (20, 20A) is inserted between the locking sections (53); characterized in that the device main body (20, 20A) has a pair of hooks (41, 41A) which are arranged in a width direction of the device main body (20, 20A) and extend in an insertion direction in which the device main body (20, 20A) is inserted between the locking sections (53); wherein the hooks (41, 41A) have respective claws (42, 42A) which are locked to the respective projections (56) from an inside side in the width direction of the device main body (20, 20A); and wherein the hooks (41, 41A) are formed closer to the mounting surface (51) in a thickness direction of the device main body (20, 20A) than a holder movement area of ​​the device main body (20, 20A).

Description

[0001] The present invention relates to a liquid level detection device according to the preamble of independent claim 1. Such a liquid level detection device is known from publication JP 2014 - 137 271 A and from publication JP H11 - 248 521 A.

[0002] Some devices for detecting the level of a liquid stored in a tank include a device main body in which the device main body is held from both sides by inserting the device main body between a pair of stoppers formed in a tank holder, and is prevented from coming out of the stoppers by locking from the outside by claws of a pair of hooks formed in the tank holder on projections that extend as two respective side sections from the device main body (refer to JP 4 591 360 B2, for example).

[0003] Devices of another type are known in which a device main body is prevented from coming out of stoppers by hooking a tank holder side hook section which is able to be elastically deformed at hook target positions formed inside in the width direction of the device main body (reference to JP 5 293 865 B2, for example).

[0004] However, in the assembly structure, disclosed in JP 4 591 360 B2, since the hooks of the tank holder side hooks are locked from the outside of the device main body, on respective projections formed on two respective side sections of the device main body, the width of the entire assembly object element is increased.

[0005] On the other hand, in the assembly structure disclosed in JP 5 293 865 B2, the width of the mounting object element is not made large, since the tank holder side hook section is hooked onto the hook target section, which is formed inside the device main body in the width direction. However, in this assembly structure, a gap is formed between the mounting surface and the hook section of the tank holder. As a result, a situation can arise where a finger, tool, or the like enters the gap and becomes caught on the hook section, unintentionally releasing the locking state. Additionally, the device main body, in which the hook target section (to which the hook section is to be hooked) extends, is made elongated in its longitudinal direction.

[0006] Further state of the art is known from documents JP 2013 - 205 195 A and JP 2013 - 171 015 A.

[0007] The present invention has been made in view of the above circumstances and an object of the invention is therefore to create a liquid level sensing device which allows a main body of the liquid level sensing device to be reliably held on a mounting object element, while enabling a reduction in the size of the liquid level sensing device.

[0008] This problem is solved according to the invention by a liquid level detection device with the features of independent claim 1. Preferred embodiments are set out in the dependent claims.

[0009] A liquid level detection device of the following points (1) to (5) will be provided: (1) An assembly structure of a liquid level sensing device for sensing a liquid level of a liquid stored in a tank, the assembly structure comprising: a mounting object element; and The liquid level detection device includes: a device main body that is mounted on a mounting surface of the mounting object element; and a holder that is attached to the main body of the device and is rotated according to a variation in the liquid level of the liquid stored in the tank, wherein the mounting object element has a pair of locking sections which lock respective side sections of the device main body when the device main body is inserted between the locking sections, and has a pair of projections which are configured to face a front section of the device main body when the device main body is inserted between the locking sections; wherein the main body of the device has a pair of hooks arranged in a width direction of the main body of the device and extending in an insertion direction in which the main body of the device is inserted between the locking sections; wherein the hooks have respective claws which are locked to the respective projections from an inner side in the width direction of the main body of the device; and wherein the hooks are formed closer to the mounting surface in a thickness direction of the device body than a holder movement area of ​​the device body. For example, the hooks between the mounting surface and the holder movement area of ​​the device body are formed in the thickness direction of the device body, and the thickness direction is perpendicular to both the width direction of the device body and the insertion direction. (2) The assembly structure of a liquid level sensing device according to point (1), wherein the device main body has lateral deformation limiting sections which come into contact with the respective hooks when the hooks are deformed inwards in the width direction of the device main body. (3) The assembly structure of a liquid level sensing device according to point (1) or (2), wherein each of the hooks, at a central position in a longitudinal direction, has an inclined section which is inclined such that it extends inwards in the width direction of the device main body when the position goes to a tip of the hook. (4) The assembly structure of a liquid level sensing device according to any of points (1) to (3), wherein each of the hooks, at its central position in its longitudinal direction, has a distance projection which projects forward in the thickness direction of the device main body. (5) The assembly structure of a liquid level sensing device according to point (4), wherein the device main body has winding deformation limiting sections which come into contact with the respective distance projections when the respective distance projections are deformed inwards in the width direction of the device main body.

[0010] In the liquid level sensing device mounting structure, which has the configuration described in point 1, the claws of the hooks of the device main body are locked to the respective projections on the mounting surface from the inside in the width direction of the device main body, thus preventing the device main body from falling. As a result, not only the width of the device main body but also the width of the entire mounting object element to which the device main body is mounted can be reduced in the structure in which a mounting object element is provided with hooks that are locked to two respective side sections of a device main body from the outside.Furthermore, the unintentional release of a locking state can be prevented, unlike in the case of a structure where a gap forms between a mounting surface and a hook section. As a result, a state in which the main body of the device is attached to the mounting object element can be reliably maintained.

[0011] Additionally, since the hooks are positioned closer to the mounting surface in the thickness direction of the main device body than the holder's movement area, the hooks can overlap with the holder's movement area when viewed from the thickness direction of the main device body. This makes it possible to reduce the size of the main device body by minimizing the length of the hook projection from the other part of the main device body.

[0012] In the fluid level sensing device assembly structure, which has the configuration of point (2), even if a hook comes into contact with a nearby component or the like and is thereby deformed inwards in the thickness direction of the device main body, the hook comes into contact with the associated lateral deformation limitation section, and therefore it is prevented from being damaged due to excessive deformation. For example, when the work of assembling the device main body on the mounting surface is carried out, an event may occur in which the device main body enters between the locking sections 53, with the device main body 20 inclined to the right or to the left.In this case, one of the pair of hooks comes into strong contact with the associated projection, resulting in a significant inward deformation of the hook in the width direction of the main body of the device. The hook, having been deformed to a large extent, then comes into contact with the associated lateral deformation limitation section, thus preventing excessive deformation. The main body of the device can therefore be gently mounted to the mounting object without the need for forceful manipulation.

[0013] In the liquid level sensing device assembly structure, which has the configuration of point (3), the tip section of each hook, in which the claw projects outwards, can be offset towards the centerline of the device main body in its width direction. As a result, the device main body can be further reduced in size. Since each hook at the center position has an inclined section in its longitudinal direction, which is angled inwards in the width direction of the device main body as it moves towards its tip, the insertion force required to insert the pair of hooks between the projections of the mounting surface, and which locks the claws to the projections, can be reduced to increase the ease of assembly, while the hooks are locked to the respective projections on the mounting surface with sufficient strength.

[0014] In the liquid level sensing device assembly structure, which has the configuration of point (4), a worker can easily deform the hooks elastically in the unlocking directions (that is, inwards in the width direction of the device main body) via the removal projections that protrude forwards in the thickness direction of the device main body, and therefore the device main body can be easily removed from the mounting object element.

[0015] In the fluid level sensing device assembly structure which has the configuration of point (5), when a worker manipulates the removal protrusions in the unlocking directions, the removal protrusions come into contact with the respective winding deformation limitation sections, thereby preventing the removal protrusions and the hooks from being damaged due to excessive deformation.

[0016] Specifically, if a worker excessively presses the removal protrusions in the unlocking direction while performing the task of removing the fixture body from the mounting object element, bending stress acts on the removal protrusions and torsional stress acts on the base sections of the hooks. At this point, since the removal protrusions come into contact with the respective winding deformation limitation sections, and the inward displacement of the removal protrusions in the lateral direction of the fixture body is limited so that they do not exceed prescribed positions, it is possible to protect the removal protrusions from being subjected to excessive bending stress and the hooks from being subjected to excessive torsional stress.As a result, the removal protrusions and hooks can be protected from damage, and the main body of the device can be removed from the mounting object element in a forceless, i.e., soft, manner.

[0017] The invention makes it possible to provide a liquid level sensing device mounting structure that allows a main body of the liquid level sensing device to be reliably held attached to a mounting object element, while enabling a reduction in size of the liquid level sensing device.

[0018] The invention is briefly described above. The details of the invention will become more apparent when the methods for carrying out the invention (hereinafter referred to as an exemplary embodiment) are read through, with reference to the accompanying drawings. Description of the drawings Fig. Figure 1 is a perspective view of a liquid level detection device. Fig. Figure 2 is a perspective exploded view of the liquid level detection device, shown in Fig. 1. Fig. 3A and Fig. Figure 3B represents a liquid level sensing device assembly structure according to one embodiment; Fig. 3A is a perspective view of a device main body attached to a mounting object element, the liquid level sensing device, and Fig. Figure 3B is a perspective view of the mounting object element to which the main body of the liquid level detection device is to be attached. Fig. 4A and Fig. 4B also represents the liquid level detection device assembly structure according to the exemplary embodiment; Fig. Figure 4A is a front view of the device main body attached to the mounting object element, the liquid level sensing device, and Fig. 4B is a front view of the mounting object element to which the main body of the liquid level detection device is to be attached. Fig. Figure 5 is a perspective view of the device main body to be attached to the mounting object element, the liquid level detection device. Fig. Figure 6 is a side view of the device main body to be attached to the mounting object element, the liquid level detection device. Fig. Figure 7 is a bottom view of the device main body to be attached to the mounting object element, the liquid level detection device. Fig. Figure 8 is a side view of a bottom part of the device's main body. Fig. Figure 9 is a section view along line BB in Fig. 8. Fig. Figure 10 is a section view along line BB in Fig. 8 and shows hooks that have a different shape. Fig. Figure 11 is a perspective view of a device main body of a liquid level detection device according to the other embodiment. Fig. Figure 12 is a side view of the device main body, shown in Fig. 11. Fig. 13A and Fig. 13B represent a liquid level sensing device assembly structure according to the other embodiment; Fig. Figure 13A is a perspective view of the device main body attached to a mounting object element, the liquid level sensing device, and Fig. Figure 13B is a perspective view of the mounting object element to which the main body of the liquid level detection device is to be attached. Fig. 14A and Fig. Figure 14B also represents a liquid level sensing device assembly structure according to the other embodiment; Fig. Figure 14A is a front view of the device main body attached to the mounting object element, the liquid level sensing device, and Fig. Figure 14B is a front view of the mounting object element to which the main body of the liquid level detection device is to be attached. Fig. Figure 15 is a section view along line CC in Fig. 14A. Detailed description of the exemplary implementation examples

[0019] An embodiment of the present invention is described below with reference to the drawings. Fig. 1 and Fig. Figures 2 are a perspective view and a perspective exploded view of a liquid level detection device 10.

[0020] As in Fig. 1 and Fig. As shown in Figure 2, the liquid level sensing device 10 comprises a device main body 20 and a holder 70. The device main body 20 includes a sensor housing 21, a terminal 22, and a retaining element 23. The terminal 22 and the retaining element 23 are attached to the sensor housing 21. A lead from a Hall effect sensor (not shown), located inside the sensor housing 21, is connected to the terminal 22. Sensing cables 24, held by the retaining element 23, are connected to the terminal 22 and extend from the top of the sensor housing 21.

[0021] The holder 70, which is circular and contains an annular magnet (not shown), is attached to a front section of the sensor housing 21 and rotatably held by it. One end section of a float arm 71 is connected to the holder 70. A float 72 is fixed to the other end section, which is a free end section of the float arm 71.

[0022] The liquid level detection device 10 is attached to a mounting object element of, for example, a fuel tank installed in a vehicle, such as an automobile, and detects a liquid level of fuel stored in the fuel tank.

[0023] In the liquid level sensing device 10, the float arm 71 oscillates as the float 72 moves by following the liquid surface. The holder 70, to which the float arm 71 is connected, rotates relative to the device's main body 20. In response, the Hall effect sensor located in the device's main body 20 detects a change in the magnetic flux generated by the magnet located in the holder 70, and a detection result is transmitted via the detection cables 24 to a measuring unit. The measuring unit determines a liquid level based on the detection result received from the Hall effect sensor and issues a warning if necessary. For example, the measuring unit issues a warning of a low fuel level in the fuel tank.

[0024] A liquid level sensing device assembly structure according to the exemplary embodiment is described below. Fig. 3A and Fig. 3B represents a liquid level sensing device assembly structure according to the exemplary embodiment; Fig. Figure 3A is a perspective view of the device main body 20, attached to a mounting object element 50, the liquid level sensing device 10, and Fig. Figure 3B is a perspective view of the mounting object element 50, to which the device main body 20 of the liquid level detection device 10 is to be attached. Fig. 4A and Fig. 4B also represents the liquid level detection device assembly structure according to the exemplary embodiment, Fig. 4A is a front view of the device main body 20, attached to the mounting object element 50, the liquid level sensing device 10, and Fig. 4B is a front view of the mounting object element 50 to which the device main body 20 of the liquid level detection device 10 is to be attached.

[0025] How Fig. 3A and Fig. Figure 4A shows the main body 20 of the liquid level sensing device 10 attached to the mounting object element 50. The mounting object element 50 is made of a resin or a metal and is provided in, for example, a fuel pump assembly attached to a fuel tank. The main body 20 is mounted from above onto a mounting surface 51 of the mounting object element 50.

[0026] As in the Fig. 3B and Fig. As shown in Figure 4B, the mounting surface 51 of the mounting object element 50 has a pair of locking sections 53 and a pair of projections 56, all of which project from the mounting surface 51. The locking sections 53 are spaced apart from each other in the left-right direction and opposite each other, and have plate-like walls 54 that are positioned parallel to each other, and locking pieces 55 that project from their upper edges in such directions that they come closer together.

[0027] The main body 20 of the liquid level detection device 10 is mounted on the mounting object element 50 by inserting the main body 20 between the locking sections 53 and sliding it in an insertion direction A (for example, downwards). The projections 56 are formed below the respective locking sections 53 (for example, on a target side in the insertion direction A). The projections 56 are spaced apart from each other so that no part of them exists outside the area defined by the outer surfaces of the locking sections 53.

[0028] Fig. Figure 5 is a perspective view of the device main body 20, which is to be attached to the mounting object element 50 of the liquid level detection device 10. Fig. Figure 6 is a side view of the device main body 20 which is to be attached to the mounting object element 50 of the liquid level detection device 10. Fig. Figure 7 is a bottom view of the device main body 20, which is to be attached to the mounting object element 50 of the liquid level detection device 10.

[0029] As in Fig. As shown in Figures 5-7, the main body of the device 20 has a holder mounting section 31 on its front side, to which the holder 70 is attached. The holder 70 is attached to the holder mounting section 31 and is rotatably held by the holder mounting section 31. The holder mounting section 31 has a range of motion MA within which the holder 70, which is attached to the holder mounting section 31, can be rotated.

[0030] Two sets of locking projections 32 are provided on side sections of the device main body 20. The front-to-back length of the locking projections 32 is slightly shorter than the interval between the mounting surface 51 and the locking elements 55 of the locking sections 53. The distance between the outer surfaces of the sets of locking projections 32 is slightly shorter than the interval between the inner surfaces of the walls 54 of the locking sections 53.

[0031] Furthermore, the main body of the device 20 is formed with stoppers 33, which are larger than the locking projections 32, in the horizontal cross-section, adjacent to the locking projections 32 on the origin side in the insertion direction A. Several surface contact sections 34 project slightly from the rear surface of the main body of the device 20.

[0032] Fig. Figure 8 is a side view of a bottom part of the device main body 20. Fig. Figure 9 is a section view along line BB in Fig. 8.

[0033] As in Fig. 8 and Fig. As shown in Figure 9, the main body of the device 20 is formed with a pair of hooks 41 at bottom positions, that is, on the target side in the insertion direction A, in which the main body of the device 20 is inserted between the locking sections 53. The hooks 41 are spaced apart from each other and extend downwards. Claws 42 project outwards from the tips of the hooks 41. The distance between the tips of the claws 42 is longer than the interval between the projections 56 of the mounting object element 50. The hooks 41 are formed on the rear surface side, that is, closer to the mounting surface 51 than the movement range MA of the main body of the device 20. Base sections and their vicinity of the hooks 41 coexist with a part of the movement range MA. This means that the hooks 41 overlap with the movement range MA when viewed from the thickness direction of the device main body 20.

[0034] The main body of the device 20 has contact sections 45 in front of the respective hooks 41, that is, on the target side in the thickness direction of the main body of the device 20. A gap G1 exists between the contact sections 45 and the hooks 41. A hook 41 comes into contact with the associated contact section 45 when the latter unintentionally moves elastically towards the front side in the thickness direction of the main body of the device 20 (indicated by a two-dot dashed line in Fig. 8) is deformed. This suppresses elastic deformation of the hooks 41 towards the front side in the thickness direction of the device main body 20.

[0035] The main body of the device 20 also has lateral deformation limiting sections 46 within the hooks 41, each in the width direction of the main body of the device 20. A gap G2 exists between the lateral deformation limiting sections 46 and the hooks 41. A hook 41 comes into contact with the associated lateral deformation limiting section 46 when the latter elastically deforms inwards in the width direction of the main body of the device 20 (indicated by a two-dot dashed line in Fig. ) is deformed. This prevents the hooks 41 from being deformed inwards in the width direction of the device main body 20 to a previously described degree.

[0036] In order to mount the device main body 20 of the liquid level detection device 10 to the mounting object element 50, the device main body 20 is oriented so that the hooks 41 are arranged on the bottom and the rear surface of the device main body 20 is opposite the mounting surface 51 in the mounting object element 50, and the device main body 20 is brought close to the mounting object element 50 from above. The device main body 20 is then inserted between the locking sections 53, while the rear surface of the device main body 20 is held parallel to the mounting surface 51, and the two sets of locking projections 32, which are the side sections of the device main body 20, are placed between the mounting surface 51 and the locking pieces 55 of the locking section 53.

[0037] Subsequently, the main body of the device 20 is pressed further downwards. As a result, the claws 42 of the hooks 41 come into contact with the respective projections 56 of the mounting object element 50 and are elastically deformed inwards in the width direction of the main body of the device 20. The main body of the device 20 is then pressed further downwards until the stoppers 33 (arranged above the locking projections 32) come into contact with the respective locking sections 53, causing the claws 42 of the hooks 41 to pass over the projections 56. Beneath the projections 56, the elastically deformed hooks 41 are returned outwards in the width direction of the main body of the device 20, and the claws 42 are locked onto the respective projections 56.

[0038] As a result, a state is achieved in which the two sets of locking projections 32, which are the two sets of side sections of the device main body 20, are locked to the respective locking sections 53 of the mounting object element 50, and the claws of the hooks 41 of the device main body 20 are locked to the respective projections 56 (the hooks do not come off the projections 56), whereby the device main body 20 is reliably mounted to the mounting object element 50. In this state, where the main body of the device 20 is mounted on the mounting object element 50, the majority of surface contact sections 34, which are formed on the rear surface of the main body of the device 20, are in contact with the mounting surface 51. As a result, the main body of the device 20 is stably fixed to the mounting object element 50 without play.

[0039] Incidentally, if the assembly of the device main body 20 onto the mounting object element 50 is carried out in the manner described above, an event may occur in which the device main body 20 is inserted at an angle to the device main body 20 between the locking sections 53 of the mounting object element 50. In this state, the tips of the hooks 41, which project towards the target side in the insertion direction A, may come into contact with the mounting surface 51 of the mounting object element 50. As a result, the hooks 41 are unintentionally elastically deformed towards the front side in the thickness direction of the device main body 20. In this case, the elastically deformed hooks 41 come into contact with the contact section 45, and are therefore prevented from being deformed further (see Fig. 8).

[0040] Another type of event can occur when the main body of the device 20 is inserted between the locking sections 53 with the main body of the device 20 inclined to the right or left side of the insertion direction A. In this event, one of the pair of hooks 41 comes into strong contact with the associated projection 56, as a result of which the hooks 41 are deformed inwards by a large amount in the width direction of the main body of the device 20. In this case, the hook 41, which has been elastically deformed by a large amount, comes into contact with the associated lateral deformation limitation section 46 of the main body of the device 20 and is therefore prevented from being excessively deformed (see Fig. 9).

[0041] As described above, in the liquid level sensing device assembly structure according to the exemplary embodiment, the claws 42 and the hooks 41 of the device main body 20 are locked to respective projections 56 on the mounting surface 51 from the inside in the width direction of the device main body 20, thus preventing the device main body 20 from falling off. As a result, not only the width of the device main body 20 but also the width of the entire mounting object element 50, on which the device main body 20 is mounted, can be made narrower than the structure in which a mounting object element is provided with hooks that are locked to two respective side sections of the device main body from the outside.Furthermore, an event in which a locking state is unintentionally released can be prevented, unlike in the case of a structure where a gap forms between the mounting surface and a hook section. As a result, the state in which the device main body 20 is attached to the mounting object element 50 can be reliably maintained.

[0042] Additionally, since the hooks 41 are formed closer to the mounting surface 51 in the thickness direction of the main body of the device 20 than the movement range MA of the main body of the device 20, the hooks 41 can overlap with the movement range MA of the holder 70 when viewed from the thickness direction of the main body of the device 20. This makes it possible to miniaturize the main body of the device 20 by minimizing the length of the projection of the hooks 41 from the other part of the main body of the device 20.

[0043] Furthermore, the main body of the device 20 has contact sections 45 with which the hooks 41 come into contact when they are deformed towards the front face in the thickness direction of the main body of the device 20. As a result, even if a hook 41 comes into contact with a nearby component or the like and is thereby unintentionally deformed towards the front face in the thickness direction of the main body of the device 20, the hook 41 comes into contact with the associated contact section 45, thus preventing it from being damaged due to excessive deformation.For example, even if the main body of the device 20 is inserted between the locking sections 53 at an angle, either forwards or backwards, and the tips of the hooks 41 thereby come into contact with the mounting surface 51, and are unintentionally deformed towards the front in the thickness direction of the main body of the device 20, the hooks 41 come into contact with the contact sections 45 and are thus prevented from being further deformed. In this way, the hooks 41 are prevented from being excessively deformed and thereby damaged. The main body of the device 20 can thus be mounted softly on the mounting object element 50 without the need for force.

[0044] Furthermore, the main body of the device 20 has lateral deformation limitation sections 46 with which the hooks 41 come into contact when they are deformed inwards in the width direction of the main body of the device 20. As a result, even if a hook 41 comes into contact with a nearby component or the like, and is thereby deformed inwards in the thickness direction of the main body of the device 20, the hook 41 comes into contact with the associated lateral deformation limitation section 46 and is thus protected from being damaged due to excessive deformation.For example, even if the main body of the device 20, inserted between the locking sections 53, is inclined to the right or left, and one of the pair of hooks 41 comes into contact with the associated projection 56 and is deformed a large area inwards in the width direction of the main body of the device 20, the hook 41 comes into contact with the associated lateral deformation limiting section 46 and is therefore prevented from being excessively deformed. In this way, the hook 41 is prevented from being excessively deformed and thus damaged. The main body of the device 20 can therefore be softly mounted on the mounting object element 50 without the need for force manipulation.

[0045] The invention is not limited to the above embodiment and various modifications, improvements, etc., can be implemented where appropriate. The materials, shapes, sets of dimensions, numbers, arrangements, etc., of the respective constituent elements of the above embodiment are not limited to those disclosed, but can be determined in a suitable manner as long as the invention can be used.

[0046] For example, as in Fig. As shown in Figure 10, each of the hooks 41 of the device main body 20 can be modified such that, at a central position in its longitudinal direction, it has an inclined section 41a which is inclined to the center line of the device main body 20 in its width direction when the position goes to its tip, whereby a tip section of each hook 41 is offset inwards.

[0047] With these modified hooks 41, the tip section of each hook 41, in which the claw 42 projects outwards, can be offset towards the center line of the main body of the device 20, in its width direction. As a result, the main body of the device 20 can be further miniaturized. Since each hook 41, at its central position in its longitudinal direction, has the inclined section 41a, which is inclined when it moves inwards in the width direction of the device main body 20 as the position moves towards its tip, the insertion force required when inserting the pair of hooks 41 between the projections 56 on the mounting surface 51 and the claws 42 locked to the projections 56 can be reduced to increase the ease of assembly, while the hooks 41 are locked to the respective projections 56 of the mounting surface 51 with sufficient strength.

[0048] Fig. 11 and Fig. Figures 12 are each a perspective view or a side view of a device main body 20A of a liquid level detection device according to another embodiment. Fig. 13A and Fig. 13B represents a liquid level sensing device assembly structure according to the other embodiment; Fig. Figure 13A is a perspective view of the device main body 20A, attached to the mounting object element 50A of the liquid level sensing device, and Fig. Figure 13B is a perspective view of the mounting object element 50A, to which the device main body 20A of the liquid level detection device is to be attached. Fig. 14A and Fig. Figure 14B also represents the liquid level detection device assembly structure according to the other embodiment; Fig. Figure 14A is a front view of the device main body 20A, attached to the mounting object element 50A of the liquid level sensing device, and Fig. Figure 14B is a front view of the mounting object element 50A to which the device main body 20A of the liquid level detection device is to be attached.

[0049] As in Fig. 11 to Fig. 14A and Fig. As shown in Figure 14B, the main body of the device 20A according to the other embodiment is in the same configuration as the main body of the device 20 described above, except for a pair of hooks 41A and winding deformation limiting sections 63. Therefore, the forming elements of the main body of the device 20A, which are the same as those in the main body of the device 20, are designated with the same reference symbols as in the latter and are not described in detail.

[0050] As in Fig. 14A and Fig. As shown in Figure 14B, a sensor housing 21A of the device main body 20A is formed with a pair of hooks 41A at bottom positions, that is, on a target side in the insertion direction A, in which the device main body 20A is inserted between locking sections 51. The hooks 41A are spaced apart from each other and extend downwards. Distance projections 61 project forwards in the thickness direction of the sensor housing 21A at half-travel positions in the longitudinal direction of the hooks 41A.

[0051] The main body of the device 20A has the winding deformation limiting sections 63 formed within the respective distance projections 61, in the width direction of the sensor housing 21A, with gaps G3 between them. When elastically deformed by being pressed inwards in the width direction, the distance projections 61A come into contact with the respective deformation limiting sections 63 (indicated by the two-dot dashed line in Fig. 15). As a result, the inward displacement of the distance projections 61 in the width direction is limited, so that they do not extend beyond the positions described above.

[0052] To mount the device main body 20A to the mounting object element 50A, the device main body 20A is oriented so that the hooks 41A are arranged on the bottom, and the rear surface of the device main body 20A is opposite the mounting surface 51 of the mounting object element 50A, and the device main body 20A is brought close to the mounting object element 50A from above. The device main body 20A is then inserted between the locking sections 53, while the rear surface of the device main body 20A is held parallel to the mounting surface 51, and the two sets of locking projections 32, which are inner side sections of the device main body 20A, are placed between the mounting surface 51 and the locking pieces 55 of the locking sections 53.

[0053] Subsequently, the main body of the device 20A is pressed further downwards, causing, as Fig. 13A and Fig. As shown in Figure 14A, a state is reached in which the claws 42A and the hooks 41A are locked onto their respective projections 56. As a result, in the same way as in the case of the device main body 20 described above, the device main body 20A is stably fixed to the mounting object element 50A without play.

[0054] To remove the main body of the device 20A from the mounting object element 50A, the hooks 41A are elastically deformed in the release directions (i.e., inwards in the width direction of the main body of the device 20A) via the removal projections 61, which project forward in the thickness direction of the sensor housing 21A. A worker can release the hooks 41A primarily by squeezing the pair of removal projections 61 together with one hand.

[0055] More specifically, how in Fig. As shown in Figure 15, when the removal projections 61 are pressed inwards in the width direction of the device main body 20A, the base sections of the hooks 41A are twisted, and the claws 42A are displaced in such directions that they move away from the respective projections 56, thereby unlocking the claws 42A from the projections 56. Since the width W over which each claw 42A is locked to the associated projection 56 is shorter than the width W of each claw 42A of the device main body 20A described above, the claws 42A are more easily disengaged from the respective projections 56 when the removal projections 61 are pressed in the unlocking directions. Thus, the hooks 41A can be easily disengaged from the respective projections 56.

[0056] The device main body 20A can be easily removed from the mounting object element 50A by spreading the pair of spacer projections 61 with one hand and lifting the device main body 20A by holding it with the other hand.

[0057] As if drawn with a two-dotted line in Fig. As indicated by 14A, a situation may arise where a worker cannot directly touch the hooks 41A because another forming element 90 is located in the vicinity of the associated projection 56 of the mounting object element 50A. Even in such a case, the worker can simply spread the removal projections 61, since the removal projections 61 extend forward in the thickness direction of the sensor housing 21A. Thus, the hooks 41A can easily be elastically deformed in the release directions via the removal projections 61, and therefore the device main body 20A can be removed from the mounting object element 50A.

[0058] Fig. Figure 15 is a section view along line CC in Fig. 14A. The main body of the device 20A has a winding deformation limitation section 63, at which the respective spacer projections 61 come into contact by being deformed inwards in the width direction. Thus, as in Fig. As shown in Figure 15, when a worker manipulates the removal projections 61 in the unlocking directions, the removal projections 61 come into contact with the respective winding deformation limitation sections 63, thereby preventing the removal projections 61 and the hooks 41A from being damaged due to excessive deformation.

[0059] More specifically, if a worker excessively presses the removal projections 61 in the unlocking directions while removing the device main body 20A from the mounting object element 50A, bending stress acts on the removal projections 61 and torsional stress acts on the base sections of the hooks 41A. At this point, since the removal projections 61 come into contact with the respective winding deformation limitation sections 63, and the inward displacement of the removal projections 61 in the width direction of the device main body 20A is limited so that they do not extend beyond the positions described above, it is possible to prevent the removal projections 61 from absorbing excessive bending stress and the hooks 41A from absorbing excessive torsional stress.As a result, the removal projections 61 and the hooks 41A can be prevented from being damaged, and the device main body 20A can be removed from the mounting object element 50A in a force-free manner, i.e. softly.

[0060] As described above, the assembly object element 50A, implemented in the other embodiment, can, in addition to the advantages provided by the device main body 20 described above, offer the advantage that a worker can easily deform the hooks 41A elastically in the unlocking directions via the removal projections 61, and therefore easily remove the device main body 20A from the assembly object element 50A.

[0061] Furthermore, when a worker manipulates the removal projections 61 in the unlocking directions, the removal projections 61 come into contact with the respective winding deformation limitation sections 63, thereby preventing the removal projections 61 and the hooks 41A from being damaged due to excessive deformation.

[0062] Thus, in the other embodiment, the device main body 20A can be easily removed from the device main body 20A and its hooks 41A provide high resistance.

[0063] Features of the liquid level detection device assembly structure described above according to the embodiment of the invention are summarized below in the form of points [1] to [5]: [1] An assembly structure of a liquid level sensing device (10) for sensing a liquid level of a liquid stored in a tank, the assembly structure comprising: a mounting object element (50, 50A); and the liquid level detection device (10) includes: a device main body (20, 20A) mounted on a mounting surface (51) of the mounting object element (50, 50A); and a holder (70) which is attached to the main body of the device and is rotated according to a variation in the liquid level of the liquid stored in the tank, wherein the mounting object element (50, 50A) has a pair of locking sections (53) which lock respective side sections of the device main body (20, 20A) when the device main body (20, 20A) is inserted between the locking sections (53), and has a pair of projections (56) which are configured to face a front section of the device main body (20, 20A) when the device main body (20, 20A) is inserted between the locking sections (53); wherein the device main body (20, 20A) has a pair of hooks (41, 41A) arranged in a width direction of the device main body (20, 20A) and extending in an insertion direction (A) in which the device main body (20, 20A) is inserted between the locking sections (53); wherein the hooks (41, 41A) have respective claws (42, 42A) which are locked to the respective projections (56) from the inside in the width direction of the device main body (20, 20A); and wherein the hooks (41, 41A) are formed closer to the mounting surface (51) in a thickness direction of the device main body (20, 20A) than a holder movement area (MA) of the device main body (20, 20A). [2] The mounting structure for the liquid level sensing device (10) according to point [1], wherein the hooks (41, 41A) are formed between the mounting surface (51) and the holder movement area of ​​the device main body (20, 20A) in the thickness direction of the device main body (20, 20A); and where the thickness direction is perpendicular to both the width direction of the device main body (20, 20A) and the insertion direction. [3] The assembly structure of the liquid level sensing device (10) according to point [1] or [2], wherein the device main body (20, 20A) has lateral deformation limiting sections (46) which come into contact with the respective hooks (41, 41A) when the hooks (41, 41A) are deformed inwards in the width direction of the device main body (20, 20A). [4] The assembly structure of the liquid level sensing device (10) according to any of points [1] to [3], wherein each of the hooks (41), at the central position in its longitudinal direction, has an inclined section (41a) which is inclined such that it extends inwards in the width direction of the device main body (20) when the position goes to a tip of the hook (41). [5] The assembly structure of the liquid level sensing device according to any of points [1] to [4], wherein each of the hooks (41A) has a distance projection (61) at its central position in its longitudinal direction, which projects forward in the thickness direction of the device main body (20A). [6] The assembly structure of the liquid level sensing device according to point [5], wherein the device main body (20A) has winding deformation limiting sections (63) which come into contact with the respective distance projections (61) when the respective distance projections (61) are deformed inwards in the width direction of the device main body (20A).

Claims

[1] A liquid level detecting device (10) for detecting a liquid level of a liquid stored in a tank, and a mounting object element (50, 50A), the liquid level detecting device (10) includes: a device main body (20, 20A) mounted on a mounting surface (51) of the mounting object element (50, 50A); and a holder (70) attached to the device main body (20, 20A) and rotated according to a variation in the liquid level of the liquid stored in the tank, wherein the mounting object member (50, 50A) has a pair of locking portions (53) which lock respective side portions of the device main body (20, 20A) when the device main body (20, 20A) is inserted between the locking portions (53), and a pair of projections (56) which are formed to face a front portion of the device main body (20, 20A) when the device main body (20, 20A) is inserted between the locking portions (53); characterized by that the device main body (20, 20A) has a pair of hooks (41, 41A) arranged in a width direction of the device main body (20, 20A) and extending in an insertion direction in which the device main body (20, 20A) is inserted between the locking portions (53); wherein the hooks (41, 41A) have respective claws (42, 42A) which are locked to the respective projections (56) from an inner side in the width direction of the device main body (20, 20A); and wherein the hooks (41, 41A) are formed closer to the mounting surface (51) in a thickness direction of the device main body (20, 20A) than a holder moving portion of the device main body (20, 20A). [2] The liquid level detecting device (10) and the mounting object element (50, 50A) according to claim 1, characterized by that the hooks (41, 41A) are formed between the mounting surface (51) and the holder movement area of ​​the device main body (20, 20A) in the thickness direction of the device main body (20, 20A); and wherein the thickness direction is perpendicular to both the width direction of the device main body (20, 20A) and the insertion direction. [3] The liquid level detecting device (10) and the mounting object element (50, 50A) according to claim 1 or 2, characterized by that the device main body (20, 20A) has lateral deformation restricting portions (46) which come into contact with the respective hooks (41, 41A) when the hooks (41, 41A) are deformed inwardly in the width direction of the device main body (20, 20A). [4] The liquid level detecting device (10) and the mounting object element (50, 50A) according to any one of claims 1 to 3, characterized by that each of the hooks (41) has, at a central position in a longitudinal direction, an inclined portion (41a) which is inclined so as to extend inward in the width direction of the device main body (20) with respect to a direction toward a tip of the hook (41). [5] The liquid level detecting device (10) and the mounting object element (50, 50A) according to any one of claims 1 to 4, characterized by that each of the hooks (41A), at the middle position in its longitudinal direction, has a removal projection (61) which projects forward in the thickness direction of the device main body (20, 20A). [6] The liquid level detecting device (10) and the mounting object element (50, 50A) according to claim 5, characterized by that the device main body (20A) has winding deformation restricting portions (63) which come into contact with the respective removal projections (61) when the respective removal projections (61) are deformed inward in the width direction of the device main body (20A).

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