JP4595529B2 - Seat load detection device - Google Patents

Description

  The present invention relates to a holding structure for smoothly carrying a seat load detecting device for detecting a load acting on a seating portion of a seat for a vehicle or the like, and assembling it to a seat or a vehicle body.

  A seat load detecting device for measuring a load acting on a seating portion of the vehicle seat is provided. By detecting the seating of the occupant or measuring the weight of the occupant by the seat load detection device, the seat belt holding function and the operation function such as the air bag are accurately controlled.

Conventionally, such a seat load detection device has used a strain gauge as disclosed in Patent Document 1, for example. The strain gauge is fixedly attached to a strain plate having one end fixed to a seat cushion such as a lower arm and the other fixed to a vehicle such as an upper rail. The seat load detection device detects the seat load by detecting a change in the characteristics of the strain gauge in accordance with the strain amount of the strain generating plate that changes depending on the load applied to the seat cushion.
JP 2003-83798 A

  However, since the strain state in the strain generating plate changes depending on the distance from the point of application of the seat load, it is necessary to accurately manage the position where the strain gauge is attached, which hinders improvement in detection accuracy of the seat load. In addition, since the strain body is set to have a relatively large plate thickness so as to receive the sheet load in a cantilever state, a change in the characteristics of the strain gauge is reduced, and an amplifier or the like is required for detection.

  Therefore, the present applicant has devised a seat load detection device using a torsion bar for the purpose of downsizing. The seat load detecting device includes a lower arm fixing member fixed to a lower arm, a torsion bar having one end fixed to the lower arm fixing member and the other end fixed to the arm member, an upper rail, and a shaft attached to the arm member. And an upper rail fixing member. The seat load detection device detects the seat load based on the amount of rotation of the arm member.

  By the way, the lower arm fixing member is loosely attached to the arm member. This facilitates detection of the seat load. When the lower arm fixing member and the arm member are fixed, the seat load applied to the seating portion of the seat acts as a force that causes the arm member to rotate and deform (bend) the arm member. The force used to deform the arm member varies depending on the distance from the fulcrum to the action point. That is, because the force for rotating the arm member varies depending on the distance from the fulcrum to the action point depending on the length of the arm member, correction or the like is necessary.

  However, since the arm member and the lower arm fixing member can be rotated relative to each other with the above-described configuration, the posture of the lower arm fixing member is not stable with respect to the upper rail fixing member and can be assembled to the vehicle body or the seat. It becomes difficult. Further, since the lower arm fixing member freely rotates at the time of conveyance or assembly, there is a risk that the lower arm fixing member may interfere with other members and be damaged.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a seat load detection device that can be smoothly conveyed and assembled to a seat or a vehicle body.

  In order to solve the above-mentioned problem, the invention according to claim 1 is a seat load detecting device for detecting a seat load acting on a seating portion of a seat, the first fixing member fixed to the floor side, and the seat side A second fixing member fixed to the first fixing member, a torsion bar having one end fixed to the first fixing member and extending in the horizontal direction, and a position fixed to the other end of the torsion bar and displaced from the torsion axis of the torsion bar An arm member pivotally supported by the second fixing member, and a torsion state detecting means having a connector portion for measuring a torsion state of the torsion bar and outputting a signal corresponding to the torsion state. And a covering member having a covering portion that covers the connector portion and a holding portion that holds the second fixing member in a non-rotatable manner.

  The invention according to claim 2 is the seat load detection device according to claim 1, wherein the covering member includes a direction in which the covering portion is removed from the connector portion, and the holding portion relative to the second fixing member. The direction of pulling out matches.

  According to the first aspect of the present invention, the connector portion can be covered from the outside by the covering member, and the arm portion and the rotating portion can be held integrally. Normally, the connector portion of the detection portion is covered with a covering member during conveyance or assembly of the sheet load detection device. Therefore, by forming the holding portion on the covering member, it is possible to suppress the relative rotation between the arm portion and the rotation portion without increasing the number of members, and the seat load detection device can be assembled to the vehicle body or the seat. It can be done smoothly.

  According to the second aspect of the present invention, since the removal direction of the covering portion and the removal direction of the holding portion are matched, the covering of the connector portion and the holding of the second fixing member can be performed by removing the covering member in one direction. Can be released.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings.
FIG. 1 shows a vehicle seat equipped with a seat load detection device according to the present invention.
As shown in FIG. 1, a vehicle seat 1 includes a seat body 2 on which an occupant is seated, a slide mechanism 4 fixed to the vehicle floor 3, and a seat load that is fixed to the slide mechanism 4 and supports the seat body 2. And a detection device 5.

The seat body 2 includes a seat cushion 6 and a seat back 7 disposed on the rear end side (right side in the state shown in FIG. 1) of the seat cushion 6.
The seat cushion 6 is a seating portion on which an occupant sits, and a seat load such as the weight of the occupant acts on the seat cushion 6. The seat cushion 6 is fixed to a pair of lower arms 6a extending in parallel in the left-right direction in the state shown in FIG. 1 on the lower end side (lower side in the state shown in FIG. 1), and seat load is applied to both ends in the longitudinal direction of the lower arm 6a. The detection device 5 is fixed. That is, the seat cushion 6 is supported by the seat load detecting device 5 disposed at the four corners of the seat cushion 6 via the lower arm 6a.

  The slide mechanism 4 includes a lower rail 4a that is arranged in parallel with the lower arm 6a of the seat cushion 6 in the longitudinal direction and is fixed to the vehicle floor 3, and an upper rail 4b that is slidably attached to the lower rail 4a. Is done. The slide mechanism 4 is a mechanism for moving the seat body 2, and the seat body 2 changes its position relative to the vehicle floor 3 in the longitudinal direction of the slide mechanism 4 when the upper rail 4 b slides with respect to the lower rail 4 a.

  The seat load detection device 5 is a seat load detection device that detects a seat load acting on the seat cushion 6. A control computer (not shown) mounted on the vehicle controls a seat belt device and an airbag device (not shown) based on the seat load detected by the seat load detection device 5.

Next, the seat load detection device 5 to which the holding structure according to the present invention is applied will be briefly described with reference to FIGS.
2 is a front view of the seat load detection device according to the present embodiment, FIG. 3 is a cross-sectional view taken along the line AA in FIG. 2, and FIG. 4 is a side view of the seat load detection device according to the present embodiment.

  As shown in FIG. 2, the seat load detection device 5 includes a fixed bracket 8 fixed to the vehicle floor 3 side, an arm member 9, a torsion bar 10 that integrally connects the fixed bracket 8 and the arm member 9, and a twist. A state detection unit 11.

  The fixed bracket 8 is formed of a plate-like member extending in the longitudinal direction of the upper rail 4b, and is fixed to the vehicle floor 3 side in a manner extending vertically upward on the upper rail 4b of the slide mechanism 4 (FIG. 1). reference).

  The arm member 9 is formed of a plate-like member extending in the longitudinal direction of the upper rail 4b, and is disposed so as to face the fixed bracket 8 by a torsion bar 10 fixed at a substantially center thereof. Moreover, the load support part 12 and the twist state detection part 11 are each arrange | positioned at the both ends.

The torsion bar 10 protrudes in the plate thickness direction with respect to the fixed bracket 8 and the arm member 9, and the torsion axis X of the torsion bar 10 is perpendicular to the vertical direction.
The torsion state detection unit 11 is a torsion state detection unit that measures the seat load from the torsion state of the torsion bar 10. The torsion state detection unit 11 is a first torsion state measurement unit 13 that is fixed to the arm member 9 and a second that is fixed to the fixing bracket 8. It is comprised from the twist state measurement part 14. FIG.

The first twist state measurement unit 13 includes a magnet 13a (see FIG. 3) at the end on the second twist state measurement unit 14 side, and is screwed to the arm member 9 on the other end side.
The second twist state measuring unit 14 is arranged in such a manner that the Hall element 14a faces the magnet 13a at the end on the first twist state measuring unit 13 side, and the Hall element 14a is electrically connected to the control computer on the other end side. A connector portion 15 for connection is formed (see FIG. 3). In addition, the outer periphery of the surface perpendicular to the longitudinal direction of the connector portion 15 is formed in a rectangular shape in which the four corners 15a are curved. The connector portion 15 protrudes from the fixed bracket 8 in the longitudinal direction of the arm member 9.

  The first torsional state measurement unit 13 disposed on one end side of the arm member 9 rotates with the torsion bar 10 as a fulcrum by applying a seat load to the load support unit 12 disposed on the other end side of the arm member 9. Move. The torsion state detection unit 11 measures the seat load by measuring the relative displacement between the magnet 13a of the first torsion state measurement unit 13 and the Hall element 14a of the second torsion state measurement unit 14. Specifically, the second torsion state measurement unit 14 has a signal having a voltage corresponding to a change in the amount of magnetic flux that affects the Hall element 14a due to a relative change in the positional relationship between the Hall element 14a and the magnet 13a. Is output.

  Further, in order to improve the detection accuracy of the seat load by the torsion state detection unit 11, a load support arm 16 fixed to the lower arm 6a is rotatably attached to the load support unit 12 of the arm member 9 via the bush 12a. Has been. In the present embodiment, the load support arm 16 is a rotating portion for the arm member 9 that is an arm portion.

  The load support arm 16 is a substantially L-shaped surface comprising a long shaft portion 17 that is in contact with the lower arm 6a (see FIG. 1) and is fixed to the seat body side, and a short shaft portion 18 that is fixed to the load support portion 12. It is a plate-shaped member which has.

  The long shaft portion 17 is formed with two support holes 17a penetrating the long shaft portion 17 in the plate thickness direction at both ends thereof. Since the load support arm 16 is screwed to the lower arm 6a by a bolt (not shown) inserted through the support hole 17a, the load support arm 16 is securely fixed to the lower arm 6a.

  The short shaft portion 18 is formed with one bearing hole 18a (see FIG. 3) penetrating the short shaft portion 18 in the plate thickness direction. The load support arm 16 has a rotating shaft 12b formed so as to protrude in the thickness direction of the arm member 9 at the load support portion 12 of the arm member 9 via a bush 12a disposed on the inner periphery of the bearing hole 18a. It is attached to the shaft. That is, since the load support arm 16 is rotatably supported with respect to the arm member 9, the moment around the load support portion acting by the seat load is suppressed, and the load support portion 12 of the arm member 9 has a seat load. Acts in the vertical direction.

Next, the holding structure of the seat load measuring device according to the present embodiment will be described.
As shown in FIGS. 2 to 3, a connector cap 19 as a covering member is attached to the sheet load detection device 5 in order to cover the connector portion 15 during conveyance or assembly.

  The connector cap 19 according to the present embodiment includes a covering portion 20 that is attached to the second torsion state measuring portion 14 and covers the connector portion 15 and a holding portion 21 that is attached to the load support arm 16. It is formed by injection molding from a polymer material such as rubber or plastic.

  The covering portion 20 includes a cup portion 20a as a concave portion formed in a substantially bottomed cylindrical shape, and a flange portion 20b formed in a manner protruding radially outward from the entire outer periphery of the bottom side end face of the cup portion 20a. I have. The cover portion 20 has the connector portion 15 press-fitted into the cup portion 20a. Therefore, the covering portion 20 does not fall off the connector portion 15 during transportation, and prevents dust, oil, and the like from entering the connector portion 15 during transportation and assembly.

The holding portion 21 includes an arm portion 21a extending outward from the outer peripheral surface 20d of the covering portion 20 and a fixing portion 21b formed at the tip of the arm portion 21a.
The arm portion 21 a is formed in a substantially L shape and is integrally formed with the covering portion 20. That is, as shown in FIG. 4, the arm member 9 is formed so as to approach the load supporting arm 16 in the plate thickness direction.

  The fixed portion 21b is formed in a substantially C shape, and the long shaft portion 17 of the load support arm 16 is fitted inside the fixed portion 21b. Since the fixing portion 21b is connected to the covering portion 20 via the arm portion 21a, the load support arm 16 cannot rotate relative to the fixing bracket 8.

As described above, the present embodiment has the following effects.
(1) The connector cap 15 including the covering portion 20 and the holding portion 21 can cover the connector portion 15 from the outside and hold the load support arm 16 and the fixed bracket 8 integrally. Therefore, the relative rotation of the load support arm 16 with respect to the fixed bracket 8 can be suppressed without increasing the number of members, and the seat load detection device 5 can be smoothly assembled to the vehicle body or the seat.

  (2) Since the fixing portion 21b is formed in a substantially C shape, the load supporting arm 16 can be easily fitted into the fixing portion 21b, that is, the load supporting arm 16 can be easily held. Further, the direction in which the covering portion 20 is removed from the connector portion 15 (withdrawal direction) and the direction in which the holding portion 21 is removed from the load support arm 16 (withdrawal direction) are made to coincide. Therefore, the covering portion 20 and the holding portion 21 can be removed from the connector portion 15 and the load support arm 16 simply by pulling the connector cap 19 in one direction. For this reason, the fall of workability | operativity can be suppressed compared with the case where the coating | coated part 20 and the holding | maintenance part 21 are pulled out in a separate direction. In addition, such a connector cap 19 can prevent forgetting to remove.

In addition, you may change embodiment of this invention as follows.
-In above-mentioned embodiment, although the arm part 21a which comprises the holding | maintenance part 21 of the connector cap 19 was formed in the substantially L shape, it is not a thing limited to such a structure. For example, the aspect of extending linearly from the outer periphery of the cup part 20a to the fixing part 21b in the radial direction can be mentioned. It is also conceivable that the cup portion 20a of the covering portion 20 is expanded toward the load support arm 16 and the connector portion 15 and the load support arm 16 are integrally held by the cup portion 20a.

  In the above embodiment, the holding portion 21 is formed in a substantially C-shape, but the shape may be changed as appropriate as long as the removal direction of the covering portion 20 and the removal direction of the holding portion 21 coincide, for example, a ring You may form in a shape.

  In the above embodiment, as long as the fixing portion 21 b is fixed to the load support arm 16, the cup portion 20 a of the covering portion 20 may be loosely attached to the connector portion 15. By fixing the fixing portion 21b to the load support arm 16, it is possible to prevent the connector cap 19 from dropping from the connector portion 15. Therefore, the cup portion 20a only needs to have a function of covering the connector portion 15. With this configuration, the relative rotation of the load support arm 16 can be suppressed in the same manner as described above, and the connector cap 19 can be easily removed after assembly, thereby improving workability.

The technical idea that can be grasped from each of the above embodiments will be described below.
(A) A holding structure for a seat load detection device according to claim 2, wherein the covering member includes a recess for accommodating the arm portion and the rotating portion. .

The front view which shows schematic structure of the vehicle seat with which the seat load detection apparatus which concerns on this invention was attached. The front view which shows the holding structure of a seat load detection apparatus. AA sectional drawing of FIG. The side view which shows the holding structure of a seat load detection apparatus.

Explanation of symbols

  X: shaft center, 5: seat load detection device, 6: seat cushion, 8 ... fixing bracket (first fixing member), 9 ... arm member, 10 ... torsion bar, 11 ... twist state detector (twist state detector) DESCRIPTION OF SYMBOLS 15 ... Connector part, 16 ... 2nd fixing member (load support arm), 19 ... Connector cap (cover member), 20 ... Cover part, 21 ... Holding part.

Claims (2)

A seat load detection device that detects a seat load acting on a seating portion of a seat,
A first fixing member fixed to the floor side;
A second fixing member fixed to the seat side;
A torsion bar having one end fixed to the first fixing member and extending in a horizontal direction;
An arm member fixed to the other end of the torsion bar and pivotally supported by the second fixing member at a position displaced from the torsional axis of the torsion bar;
A torsional state detecting means having a connector part for measuring the torsional state of the torsion bar and outputting a signal corresponding to the torsional state;
A covering member having a covering portion that covers the connector portion and a holding portion that holds the second fixing member in a non-rotatable manner;
A seat load detection device comprising:   The seat load detection device according to claim 1, wherein a direction in which the covering portion is removed from the connector portion coincides with a direction in which the holding portion is removed from the second fixing member.

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