JP2006076335A - Load sensor mounting structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a load sensor mounting structure capable of preventing a load sensor from detecting unnecessary load caused by distortion, inclination or axial force of tightening of a mounting plate part and carrying out accurate load detection. <P>SOLUTION: In the structure, a male screw 36 is provided on a load detecting part 38 side of the load sensor 25 for measuring the load and the load sensor 25 is mounted to the mounting plate part 26 by a nut 50 for screwing the male screw 36. The structure comprises a washer part 41 provided between a load detecting part 38 and the mounting plate part 26 for approximately covering the load detecting part 38 and a collar part 42 thicker than the plate thickness of the mounting plate part 26 provided between the washer part 41 and the nut 50. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a load sensor mounting structure.

For example, in order to control the deployment of the airbag device at the time of a vehicle collision, a load sensor that detects the load applied to the seat is provided, and whether the passenger is seated on the seat and whether the seated passenger is an adult It is performed to determine whether the child is a child. With regard to such a load sensor, stud bolts are provided so as to protrude upward and forward of the sliders of the left and right seat rails, and one end portion of the plate member is fixed to the tip portion of the stud bolt after passing through the seat frame. There is one that detects the amount of deformation of the plate member by fixing the other end of the plate member to the seat frame (see, for example, Patent Document 1).
US Pat. No. 6,161,891

  By the way, as shown in FIG. 6, a male screw 102 is provided on the load detection unit 101 side of the load sensor 100, and the load sensor 100 is set to the load detection unit 101 on the upper side as shown in FIG. In the case of a structure in which the mounting plate portion 104 of the seat frame is attached to the load sensor 100 by the nut 103 screwed to the male screw 102, the load detecting portion 101 and the mounting plate portion 104 are free from play by the nut 103. Once fastened, the load is detected by the load sensor 100 even when the seat plate mounting plate 104 is distorted or tilted due to a light vehicle collision, and the load sensor 100 detects an unnecessary load. End up. For this reason, as shown in FIG. 7, a collar 105 is provided between the load detection unit 101 and the nut 103, and a gap allowing distortion and inclination of the mounting plate unit 104 is provided between the nut 103 and the load detection unit 101. Even in this case, the fastening force is locally applied to the load detection unit 101 via the collar 105, and as a result, the load sensor 100 detects an unnecessary load. (In other words, axial force drift occurs).

  Therefore, the present invention can prevent the load sensor from detecting an unnecessary load due to the distortion and inclination of the mounting plate part and the fastening axial force, and can perform accurate load detection. The purpose is to provide a structure.

  In order to achieve the above-described object, the invention according to claim 1 is directed to a load sensor (for example, the load sensor 25 in the embodiment) for measuring a load and a male screw ( For example, a male screw 36 in the embodiment or a female screw is provided, and the load sensor is attached to the mounting plate portion (for example, the mounting plate in the embodiment) by a nut (for example, the nut 50 in the embodiment) or a bolt that is screwed to the male screw or the female screw. In the load sensor mounting structure to be attached to the portion 26), a washer portion (for example, the washer portion 41 in the embodiment) that substantially covers the load detection portion and is interposed between the load detection portion and the attachment plate portion, A collar portion (for example, an implementation) provided between a washer portion and a head of the nut or bolt is thicker than the thickness of the mounting plate portion. It is characterized by having a collar portion 42) and the state.

  The invention according to claim 2 is characterized in that, in the invention according to claim 1, the washer portion and the collar portion are integrally formed.

  According to the first aspect of the invention, the washer portion that substantially covers the load detection portion and is interposed between the load detection portion and the mounting plate portion, and between the washer portion and the head of the nut or bolt. Since the collar portion is thicker than the plate thickness of the mounting plate portion provided, a gap that can absorb the strain and inclination of the mounting plate portion is formed between the head portion of the nut or bolt and the washer portion by the collar portion. It will be. Therefore, unnecessary load detection due to distortion and inclination of the mounting plate portion can be prevented, and accurate load detection can be performed. Further, the fastening axial force introduced through the collar part can be dispersed on the load detection part on the average by the washer part. Therefore, it is possible to prevent the load sensor from detecting an unnecessary load due to the fastening axial force, and also to reduce variations in the initial value of the sensor due to a difference in tightening torque, thereby enabling accurate load detection. it can.

  According to the invention which concerns on Claim 2, since the washer part and the collar part are integrally molded, the number of parts and an assembly man-hour can be reduced.

A load sensor mounting structure according to an embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 shows a right half of a seat 11 of a passenger seat of a vehicle. This seat 11 is a pair of seat rails 14 to which a seat frame 12 constituting a skeleton thereof is attached to a vehicle body floor 13 so as to be separated from each other on the left and right. (Only one is shown) so that it can slide back and forth.

  Each of the pair of seat rails 14 is supported by a rail body 20 attached to the vehicle body floor 13 in a posture extending in the vehicle body longitudinal direction, and slidable in the vehicle body longitudinal direction in a posture extending in the vehicle body longitudinal direction. The slider 21 is provided.

  A load sensor 25 for measuring the load is attached to the front end portion and the rear end portion of each slider 21 in the longitudinal direction of the vehicle body in a mounted state, and the load sensors 25 before and after the slider 21 on one side in the vehicle width direction. A mounting plate 26 on one side in the vehicle width direction at the bottom of the seat frame 12 is attached to the load sensor 25 before and after the slider 21 on the opposite side in the vehicle width direction. Part 26 is attached.

  As shown in FIG. 2, the load sensor 25 has a base plate portion 31 that is long in one direction. The base plate portion 31 is in a posture along the vehicle body front-rear direction (the left-right direction in FIG. 2), The rear portion is attached to the slider 21 with a bolt 32.

  The load sensor 25 is attached to the slider 21 in the base plate portion 31 as described above, and has a substantially cylindrical sensor main body portion 35 for detecting a load on the upper surface of the intermediate portion of the base plate portion 31 in the longitudinal direction of the vehicle body. Is fixed along the axial direction, and a male screw 36 is fixed to the sensor main body 35 so as to protrude upward from the center position of the upper surface along the substantially horizontal direction.

  Here, in the sensor main body 35, the portion excluding the male screw 36 on the upper surface side is a load detection unit 38 that detects a load. In other words, the male screw 36 is formed on the load detection unit 38 side of the load sensor 25. Has been. The sensor main body 35 detects a load mainly introduced downward from the load detection unit 38 by itself being slightly distorted.

  A washer 40 is provided in the sensor body 35 so that the male screw 36 is inserted. The washer 40 includes a perforated disc-shaped washer portion 41 having substantially the same outer diameter as the load detecting portion 38, and a washer portion 41 that is coaxial with the washer portion 41 and protrudes vertically from the washer portion 41. Also, the cylindrical collar portion 42 having a small outer diameter is integrally formed, and the inner diameter side of the washer portion 41 and the collar portion 42 have the same diameter, thereby forming an insertion hole 43 penetrating in the axial direction. ing. The insertion hole 43 has a diameter through which the male screw 36 can be inserted. With the male screw 36 inserted into the insertion hole 43 and the washer 41 in contact with the load detection unit 38, the washer 40 is connected to the sensor body 35. Placed on. In this state, the washer 40 covers the entire load detection unit 38 in the washer portion 41, and the male screw 36 of the load sensor 25 protrudes upward from the washer 40. The upper surface of 41 and the upper surface of the collar portion 42 are parallel to the upper surface of the load detection unit 38. In addition, the outer diameter of the washer part 41 should just be more than the outer diameter of the load detection part 38. FIG.

  Thus, the collar portion 42 of the washer 40 through which the male screw 36 of the load sensor 25 is inserted is inserted into the mounting hole 45, and the mounting plate portion 26 of the seat frame 12 is placed on the washer portion 41. Here, the axial length (thickness) of the collar portion 42 is made thicker than the plate thickness of the mounting plate portion 26, and therefore, the collar portion 42 is above the mounting plate portion 26 that contacts the washer portion 41. Protruding.

  A wave washer (elastic body) 47 that is annular and has an outer diameter larger than the outer diameter of the washer portion 41 is inserted through the collar portion 42 that protrudes upward from the mounting plate portion 26. It is mounted on the mounting plate portion 26 in contact. When the wave washer 47 is not deformed, the axial length (thickness) is longer than the value obtained by subtracting the plate thickness of the mounting plate portion 26 from the axial length of the collar portion 42, and the wave washer 47 is most axially extended. In the contracted state, the axial length is shorter than the value obtained by subtracting the plate thickness of the mounting plate portion 26 from the axial length of the collar portion 42. Therefore, the upper end portion of the wave washer 47 is positioned above the upper end surface of the collar portion 42 in a state where it is placed on the mounting plate portion 26 and is not deformed.

  In this state, a washer 49 is placed on the wave washer 47 so that the male screw 36 protruding further upward is inserted inside. Here, the washer 49 has an inner diameter larger than that of the male screw 36 and smaller than an outer diameter of the collar portion 42, and the outer diameter is substantially the same as the outer diameter of the wave washer 47.

  In this state, the nut 50 is screwed into the male screw 36 that protrudes further upward, and the nut 50 is tightened with a predetermined torque. Then, the washer 49 and the washer 40 are fastened and fixed by the nut 50 and the load sensor 25. That is, the lower surface of the nut 50 and the upper surface of the washer 49 are in contact with no gap, the lower surface of the washer 49 and the upper surface of the collar portion 42 of the washer 40 are in contact with no gap, and the lower surface of the washer portion 41 of the washer 40 and the sensor body portion. It will be in the state which contacts the upper surface of 35 load detection parts 38 without a gap. At this time, the washer 49 and the washer 40 are brought close to each other, so that the wave washer 47 provided between them is elastically deformed, and the elastic force of the wave washer 47 causes the mounting plate portion 26 of the seat frame 12 to move. It will be pressed against the washer part 41 of the washer 40 on the lower side.

  In this way, the load sensor 25 is attached to the mounting plate portion 26 by the nut 50 that is screwed into the male screw 36 provided in the load sensor 25. In this state, the washer portion 41 of the washer 40 substantially covers the load detection portion 38 and is interposed between the load detection portion 38 and the mounting plate portion 26. A collar portion 42 thicker than the plate thickness of the mounting plate portion 26 is provided therebetween. Further, in this state, a wave washer 47 is provided between the mounting plate portion 26 and the nut 50.

  As described above, the seat frame 12 of the seat 11 is supported by the left and right seat rails 14 via the four load sensors 25 at the four corners. Then, the load introduced into the seat 11 is introduced from the seat frame 12 to the load detection unit 38 of the load sensor 25 through the washer portion 41 of the washer 40 that contacts the seat frame 12, and the sensor main body 35 is loaded with the load. Electric charges corresponding to the load are generated by being slightly distorted, whereby a control unit (not shown) detects the load. Then, the control unit determines from the loads detected by the four load sensors 25 whether or not the occupant is seated on the seat 11, whether the occupant seated is an adult or a child, and the like. Thus, for example, the deployment of the airbag device at the time of a vehicle collision is controlled.

  According to the embodiment described above, the washer portion 41 that substantially covers the load detection portion 38 and is interposed between the load detection portion 38 and the mounting plate portion 26, and between the washer portion 41 and the nut 50. A collar portion 42 that is thicker than the plate thickness of the mounting plate portion 26 (specifically, thicker than the total plate thickness of the mounting plate portion 26 and the minimum plate thickness of the wave washer 47). Therefore, the collar portion 42 absorbs the distortion and inclination of the mounting plate portion 26 between the nut 50 and the washer portion 41 (specifically, between the washer 49 and the washer portion 41) as shown in FIG. A gap that can be formed is formed. Therefore, the load sensor 25 can prevent detection of unnecessary load due to distortion or inclination of the mounting plate portion 26 caused by a light vehicle collision or the like, and accurate load detection can be performed.

  Further, the fastening axial force introduced through the collar portion 42 can be dispersed on the load detection portion 38 on the average by the washer portion 41. Therefore, unnecessary load detection (so-called axial force drift) due to the fastening axial force can be prevented, and variations in the sensor initial value due to the difference in fastening torque can be reduced, so that accurate load detection can be performed. . That is, in the case of only the collar, the range excluding the weight of the seat and the amount of fastening axial force drift among the detection range of the load sensor is a range that can be used for occupant detection. By using the provided washer 40, the range excluding only the weight of the seat in the detection range of the load sensor becomes a range that can be used for occupant detection, and the width of load detection becomes larger.

  In addition, since the wave washer 47 is provided between the mounting plate portion 26 and the nut 50, either when the mounting plate portion 26 is not distorted or inclined, or when the mounting plate portion 26 is distorted. In this case, the wave washer 47 is deformed according to the distortion and inclination, so that the mounting plate portion 26 can be prevented from rattling due to the gap between the washer 49 and the washer portion 41.

  Furthermore, since the washer portion 41 and the collar portion 42 are integrally formed, the number of parts and the number of assembling steps can be reduced. Of course, the washer portion 41 and the collar portion 42 can be separated.

  Note that another elastic body may be used instead of the wave washer 47 described above. For example, as shown in FIG. 4, an annular flat plate between the nut 50 and the washer 40 along the axial orthogonal direction on the inner diameter side. A plate spring-shaped washer 52 having a portion 53 and an annular tapered plate portion 54 inclined with respect to the axial orthogonal direction on the outer diameter side is provided, and the flat plate portion 53 is brought into contact with the lower surface of the nut 50 and the upper surface of the collar portion 42. The lower end surface of the taper plate portion 54 may be brought into contact with the mounting plate portion 26. Furthermore, as shown in FIG. 5, both sides of a leaf spring 62 having an annular flat plate portion 60 along the axial orthogonal direction on the inner diameter side and an annular tapered plate portion 61 inclined with respect to the axial orthogonal direction on the outer diameter side are provided with washers. These may be sandwiched between 63 and 64 and provided between the nut 50 and the washer 40. In this case, a small outer diameter washer 63 is disposed on the opposite side to the extending direction of the taper plate portion 61 in the axial direction of the flat plate portion 60, and a large outer diameter washer 64 is disposed on the opposite side. The washer 64 is brought into contact with the upper surface of the collar portion 42, and the lower end portion on the outer diameter side of the tapered plate portion 61 protruding from the washers 63, 64 is brought into contact with the mounting plate portion 26. In the example of FIG. 5, a resin cover 66 is provided in the mounting hole 45 of the mounting plate portion 26 to prevent the mounting plate portion 26 and the washer 40 from hitting the edge.

  In the above description, the male screw 36 is provided on the load detection unit 38 side of the load sensor 25 for measuring the load, and the load sensor 25 is attached to the mounting plate 26 by the nut 50 screwed to the male screw 36. As described above, a structure may be adopted in which a female screw is provided on the load detection unit 38 side of the load sensor 25 and the load sensor 25 is attached to the mounting plate part 26 with a bolt screwed into the female screw. In this case, the bolt shaft portion is inserted into the insertion hole 43 of the washer 40, the collar portion 42 of the washer 40 is provided between the washer portion 41 and the bolt head portion, and the wave washer 47 is provided. It is provided between the mounting plate portion 26 and the head of the bolt.

1 is a partial perspective view showing a vehicle seat to which a load sensor mounting structure according to an embodiment of the present invention is applied. It is the side view which made a part the cross section which shows the load sensor attachment structure of one Embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is the side view which made the cross section the part which shows the load sensor attachment structure of one Embodiment of this invention, Comprising: The state which the attachment board part inclined is shown. It is the side view which made a part the cross section which shows the modification of the load sensor attachment structure of one Embodiment of this invention. It is the side view which made a part the cross section which shows another modification of the load sensor attachment structure of one Embodiment of this invention. It is the side view which made a part the cross section which shows an example of the load sensor attachment structure. It is the side view which made a part the cross section which shows another example of the load sensor attachment structure.

Explanation of symbols

25 Load sensor 26 Mounting plate part 36 Male screw 38 Load detection part 41 Washer part 42 Collar part 50 Nut

Claims (2)

A load sensor mounting structure in which a male screw or a female screw is provided on a load detection unit side of a load sensor for measuring a load, and the load sensor is attached to a mounting plate portion by a nut or a bolt screwed to the male screw or the female screw. ,
A washer that substantially covers the load detector and is interposed between the load detector and the mounting plate; and the mounting plate provided between the washer and the nut or bolt head A load sensor mounting structure comprising a collar portion thicker than a plate thickness of the portion. The load sensor mounting structure according to claim 1, wherein the washer portion and the collar portion are integrally formed.

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