JP4802913B2 - Seat load detection device - Google Patents

Description

  The present invention relates to a seat load detection device.

  Conventionally, as shown in FIG. 8, it is assumed that the load of an occupant or the like acting on a vehicle seat S1 is detected and used for controlling various devices (for example, an air bag, a warning lamp, etc.). A detection device S110 is known. The seat load detecting device S110 is configured to support the total weight including the seat S1 and an occupant on the seat S1 or an attached device such as a child seat (not shown) on the floor S2 via the seat load detecting device S110. It has become. The seat load detection device S110 includes four load sensors S120 that are arranged at predetermined intervals from each other at the front, rear, left, and right positions below the seat S1.

  Further, as shown in FIGS. 6 and 7, the load sensor S120 includes a flat plate-shaped elastic member S125 that is elastically deformed by a load acting on the sheet S1. The elastic member S125 is fixedly supported by the anchor member S150 at two locations, that is, the front-side fixed support portion S123 and the rear-side fixed support portion S124 that are arranged at a predetermined interval in the front-rear direction. Fixed and supported on the S2 side. The action support member S126 is fixed at a central position between the two support fixing portions S123 and S124, and the action support member S126 is connected to a seat slide device S130 that supports the seat S1. With this configuration, the elastic member S125 is elastically deformed by a load acting on the sheet S1 transmitted through the action support member S126.

  A front strain detection sensor S127 and a rear strain detection sensor S128 are attached to the surface of the elastic member S125 between the two support fixing portions S123 and S124 and the action support member S126. The strain detection sensors S127 and S128 output voltage fluctuations generated as a result of elastic deformation of the elastic member S125 as signals.

The load detection is performed not only when the vehicle is stopped but also when the vehicle is running. As shown in FIGS. 6 and 7, as the load from the seat S1, the horizontal load F mainly generated by acceleration / deceleration, turning, etc. of the vehicle, the weight of the occupant, the weight of the seat S1 and the attached device, A load W _{0 in the} vertical direction due to vibration acts on the load sensor S120.

Output signals from the front strain detection sensor S127 and the rear strain detection sensor S128 of the load sensor S120 are added together. Here, the horizontal load F is further a longitudinal direction of the component force f ₀ vertical, can be decomposed into a component force f next to the lateral direction. Component force f ₀ vertical in this longitudinal direction, the strain of the compression on the front side of the strain detecting sensor S127 is, the strain detection sensor S128 the rear and as strain extends is detected, acts. Further, the lateral component force f ₀ horizontal well, in both the strain detection sensors S127, S128, the strain corresponding to the opposite direction of the bending together as respectively detected, acts. For this, signals from both strain detection sensors S127, S128 by being addition processing, the output of the ₀ horizontal component force f ₀ vertical and the component force f cancel each other out. That is, the influence of the load F ₀ in the horizontal direction, will be erased from the output of the load sensor S120.

On the other hand, the load W _{0 in the} vertical direction becomes a double output value by the addition processing of the output signals from the strain detection sensors S127 and S128. In order to halve this output value and eliminate the influence of fluctuations due to vertical vibrations of the vehicle, a value indicating only the weight can be obtained by averaging the detected values for a predetermined elapsed time.

Originally, the elastic member S125 having a flat plate shape and arranged in the horizontal direction is easily elastically deformed with respect to a load in the vertical direction, and has an advantageous configuration for detecting the weight. However, since the influence of the horizontal load F can be eliminated by employing the two strain detection sensors S127 and S128 as in the above configuration, the load acting on the sheet S1 can be detected with higher detection accuracy. It is configured (see, for example, Patent Document 1).
JP-A-2005-134340

  However, in the conventional seat load detection device, two strain detection sensors are required for each of the four load sensors. For this reason, a total of eight strain detection sensors and an electric circuit for operating these strain detection sensors are also required individually.

  The present invention has been made in view of the above-described conventional situation, and an object to be solved is to provide a seat load detection device capable of reducing cost while maintaining detection accuracy.

  The technical means taken in the present invention in order to solve the above-mentioned problem, as described in claim 1, is a first load sensor disposed on the left front side of the seat and receiving a load from the seat side, and A second load sensor disposed on the left rear side of the seat and receiving a load from the seat side; a third load sensor disposed on the right front side of the seat and receiving a load from the seat side; and the seat And a fourth load sensor that receives a load from the seat side, and the first to fourth load sensors are arranged at predetermined intervals in the front-rear direction of the seat. An elastic member supported on the floor side by the front support fixing portion and the rear support fixing portion, and a load from the seat side to the elastic member at a central position of the front support fixing portion and the rear support fixing portion. Action transmission In the seat load detection device provided with a member, the first and fourth load sensors include the action support member and the front side fixed support part, or the action support member and the rear side fixed support part. The first and fourth strain detection sensors are attached to the elastic member at either one of the positions between the first and second load sensors, and the second and third load sensors are provided between the action support member and the front fixed support portion. Alternatively, the second and third strain detection sensors are attached to the elastic member at a position on the other side between the action support member and the rear fixed support portion.

  According to a second aspect of the present invention, the technical means provided in the present invention is characterized by including a connecting and fixing member that connects the action supporting members of the first to fourth load sensors.

  According to the first aspect of the present invention, the seat load is maintained while the detection accuracy is maintained by the four strain detection sensors, which is half the number, compared to the conventional seat load detection device that requires eight strain detection sensors. Can be realized. For this reason, in the seat load detection device of the present invention, not only the strain detection sensor but also an electric circuit for operating the strain detection sensor is reduced, and the cost can be greatly reduced.

  According to the second aspect of the present invention, since the connection fixing member for connecting the action supporting members of the first to fourth load sensors to each other is provided, each load sensor is connected via the connection fixing member. Thus, the load from the seat is transmitted. For this reason, in the seat load detection device of the present invention, the load from the seat is uniformly transmitted to each load sensor, and high detection accuracy can be exhibited.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS The best mode for carrying out the present invention will be described below with reference to the drawings.

(Embodiment)
FIG. 1 shows a seat device 10 including a seat load detection device 20 of the embodiment in a side view from the left side. In the drawing, the front, rear, right, and left directions of the seat device 10 are indicated by arrows as necessary for explanation. Further, the configuration of the seat device 10 is symmetrical unless otherwise described below.

  A seating posture adjusting device 30 for adjusting the seating surface height and the backrest angle of the seat main body 1 is attached to the seat device 10 so as to be positioned below the seat main body 1 on which an occupant sits. The seating posture adjusting device 30 is arranged at a predetermined interval in the front-rear direction and extends downward, a front link arm 31, a rear link arm 32, and a frame body 35 (for example, a connection) connected to the lower ends of the link arms 31, 32. An example of a fixing member). The frame body 35 includes a pair of left and right frame members 35a extending horizontally in the front-rear direction, and the left and right frame members 35a are connected by connecting members 35b at the front and rear ends. The frame body 35 is a structure having predetermined strength and rigidity.

  A seat slide device 50 having a known mechanism for adjusting the seating position in the front-rear direction is attached to the floor 2 of the vehicle. The seat slide device 50 includes a lower rail 51 and an upper rail 52 that extend horizontally in the front-rear direction, and the upper rail 52 is guided by the lower rail 51 and moves back and forth by the operation of the drive device 53. On the upper rail 52, a reinforcing bracket 55 is disposed substantially over the entire length of the upper rail 52.

  As shown in FIGS. 1, 3, 4, and 5, the seat load detection device 20 is disposed between the upper surface of the reinforcing bracket 55 and the frame body 35. The seat load detection device 20 includes a total of four load sensors 21, 22, 23, 24, two on the right side of the seat device 10 and two on the left side.

  FIG. 2 shows the load sensor 21 in detail. The other load sensors 22, 23, 24 have the same structure as the load sensor 21 except for a part described later. The load sensor 21 is an elastic body having a strength made of a material such as steel, and includes a sensor plate 26 as a flat plate-like elastic member that extends long in the front-rear direction and has a rectangular shape in plan view. A front support fixing portion 27 and a rear support fixing portion 28 which are provided so as to penetrate the sensor plate 26 vertically are fixed to the front end and the rear end portion of the sensor plate 26 together with the presser plate 25. It is done. A screw-like action support portion 29 is fixedly attached to the center position between the support fixing portions 27 and 28 so as to extend vertically upward from the sensor plate 26.

  As shown in FIGS. 4 and 5, the load sensors 21 and 22 are on the left upper rail 52, and the load sensors 23 and 24 are on the right upper rail 52 via the reinforcing bracket 55, respectively. , 28 through screw means. On the other hand, the upper ends of the action support portions 29 of the load sensors 21, 22, 23, 24 are fixedly attached to the frame body 35 and are firmly connected to each other.

  Note that the frame body 35 is not a component that constitutes the seating posture adjustment device 30, and may be, for example, an individual member that firmly connects the action support portions 29. Further, for example, the constituent members of the seat body 1 may be provided with sufficient strength so that the action support portions 29 are connected.

  Next, as shown in FIGS. 2 to 5, one strain detection sensor 81, 82, 83, 84 is attached to the upper surface of the sensor plate 26 of the four load sensors 21, 22, 23, 24, respectively. . Examples of the sensor plate 26 include a strain generating body, and examples of the strain detection sensor include a strain gauge. The characteristics of the strain detection sensors 81, 82, 83, 84 are the same. In the load sensor 21 (e.g., an example of the first load sensor) disposed on the left front side, the strain detection sensor 81 (e.g., the first load sensor 27) is disposed at a position between the action support member 29 and the front support fixing portion 27. An example of a strain detection sensor is attached. Unlike the load sensor 21, the load sensor 22 (for example, a second load sensor) disposed on the left rear side is distorted at a position between the action support portion 29 and the rear support fixing portion 28. A detection sensor 82 (for example, an example of a second strain detection sensor) is attached. Further, a load sensor 23 (for example, a third load sensor) arranged on the right front side is the same as the load sensor 22, and unlike the load sensor 21, the action support member 29 and the rear support fixing portion 28. A strain detection sensor 83 (for example, an example of a third strain detection sensor) is attached at a position between the two. Further, in the load sensor 24 (for example, an example of the fourth load sensor) arranged on the right rear side, unlike the load sensors 22 and 23, similarly to the load sensor 21, the action support portion 29 and the front support fixing portion. 27, a strain detection sensor 84 (for example, an example of a fourth strain detection sensor) is attached to the position.

  The mounting positions of the strain detection sensors 81, 82, 83, 84 are determined by the mutual relationship between the load sensors 21, 22, 23, 24 according to the operating principle described later. Even if arranged in the same manner, it functions similarly.

  As the strain detection sensors 81, 82, 83, 84, a general-purpose sensor in which four resistors are combined with a bridge circuit so as to detect a minute elastic deformation of a metal and output it as a voltage value can be used. Although not shown, a control device for operating the strain detection sensors 81, 82, 83, 84, a data processing device for processing output signals from the strain detection sensors 81, 82, 83, 84, and electrical wiring are provided. It is done.

The seat load detection device 20 configured as described above always detects a load acting on the seat body 1 at a short cycle of, for example, several tens of milliseconds, not only when the vehicle is stopped but also during traveling. As shown in FIGS. 3, 4, and 5, the load shared by each of the load sensors 21, 22, 23, 24 in response to the load from the seat device 1 side is a load component W _{1 in the} vertical direction. W ₄ and the horizontal load components F _{1 to} F ₄ are assigned to the load sensors 21, 22, 23, and 24 to indicate the respective shared loads. As shown in these figures, the horizontal load components F _{1 to} F ₄ are decomposed into a longitudinal component force F _{1 to} F ₄ and a lateral component force F _{1 to} F ₄ side. Can do.

As described above, the action support portions 29 of the load sensors 21, 22, 23, and 24 are firmly connected to each other in the front-rear direction by the frame body 35. For this, the front-rear direction of the force component F ₁ vertical and F ₂ vertical acting on the load sensor 21 and the load sensor 22 becomes substantially equal. Similarly, longitudinal force components F ₃ and F ₄ acting on the load sensor 23 and the load sensor 24 are substantially the same.

As for the force component F ₁ transverse to F ₄ horizontal lateral, transverse force component F ₁ horizontal and F ₃ horizontal, but also the load sensor 22 and the load sensor which acts on the load sensor 21 and the load sensor 23 as well lateral component force F ₂ lateral and F ₄ laterally acting 24 is substantially identical.

In the load sensor 21, the strain detection sensor 81 is attached between the action support portion 29 and the front support fixing portion 27. In the load sensor 22, the strain detection sensor 82 is connected to the action support portion 29 and the rear support fixing portion. 28, and are attached to positions opposite to each other with respect to the action support portion 29. For this purpose, the sheet device is added in a manner similar to the signal processing used in the known technical example cited at the beginning, in which output signals from both strain detection sensors 81 and 82 of the load sensor 21 and the load sensor 22 are added. longitudinal force component F ₁ vertical acting on the first left, the influence of the F ₂ vertical output (moment in the longitudinal direction of the seat apparatus 1) can be erased.

Similarly, the load sensor 23 and the load sensor 24 may affect the output of the longitudinal component F ₃ and F ₄ acting on the right side of the seat device 1 depending on the output signal addition processing (the seat device 1 Can be eliminated.

More Similarly, the load sensor 21 and load sensor 23, in combination with the load sensor 22 and load sensor 24, the lateral component of force F ₁ transverse to F ₄ next to the output acting on the front and rear of the seat apparatus 1 the influence of (a moment in the lateral direction of the seat apparatus 1) can be erased on the same principle as in the case of the component force F ₁ vertical to F ₄ vertically.

  Detection of a predetermined elapsed time in order to add up and down load W1, W2, W3, W4 shared by each load sensor 21, 22, 23, 24 and eliminate the influence of fluctuation due to vertical vibration of the vehicle By averaging the values, a value indicating only the weight can be obtained as in the known technical example.

  As described above, the seat load detection device 20 according to the embodiment is configured to include one strain detection sensor 81, 82, 83, 84 for each load sensor 21, 22, 23, 24. In contrast to the conventional technique in which two load sensors have two strain detection sensors, it is possible to achieve a configuration that can be manufactured at a lower cost while maintaining detection accuracy.

  In the seat load detection device 20 as described above, the positions of the strain detection sensors 81, 82, 83, and 84 of the load sensors 21, 22, 23, and 24 may be symmetrical with respect to the seat device 1. Is possible.

It is a side view from the left side of a seat apparatus provided with a seat load detector concerning an embodiment. It is sectional drawing of the load sensor of the seat load detection apparatus according to the embodiment. It is a top view which shows arrangement | positioning of each load sensor of a load detection apparatus according to the embodiment. FIG. 4 is a side view taken along the arrow IV in FIG. 3 according to the embodiment. FIG. 4 is a side view as viewed in the direction of arrow V in FIG. 3 according to the embodiment. It is a top view of the load sensor of the seat load detection apparatus shown by the prior art. It is a side view of the load sensor of the seat load detection apparatus shown by the prior art. It is a perspective view of a seat device provided with a seat load detection device shown in prior art.

Explanation of symbols

1 ... Seat body (sheet)
21 ... Load sensor (first load sensor)
22 ... Load sensor (second load sensor)
23 ... Load sensor (third load sensor)
24 ... Load sensor (fourth load sensor)
26 ... Sensor plate (elastic member)
27: Support fixing part (front support fixing part)
28: Supporting and fixing part (rear supporting and fixing part)
29 ... action support part (action support member)
35 ... Frame body (connection fixing member)
81 ... Strain detection sensor (first strain detection sensor)
82 ... Strain detection sensor (second strain detection sensor)
83 ... strain detection sensor (third strain detection sensor)
84: Strain detection sensor (fourth strain detection sensor)

Claims (2)

A first load sensor disposed on the left front side of the seat and receiving a load from the seat side;
A second load sensor disposed on the left rear side of the seat and receiving a load from the seat side;
A third load sensor disposed on the right front side of the seat and receiving a load from the seat side;
A fourth load sensor disposed on the right rear side of the seat and receiving a load from the seat side;
Each of the first to fourth load sensors includes a front support fixing portion and a front support fixing portion arranged on the floor side with a predetermined interval in the front-rear direction of the seat, and the front support In the seat load detection device provided with an action support member that transmits a load from the seat side to the elastic member at a center position of the fixing portion and the rear support fixing portion,
The first and fourth load sensors include the elasticity at a position on either one side between the action support member and the front side fixed support part or between the action support member and the rear side fix support part. First and fourth strain detection sensors are attached to the member,
The second and third load sensors include the elasticity at a position on the other side between the action support member and the front fixed support part or between the action support member and the rear fixed support part. A seat load detecting device, wherein second and third strain detection sensors are attached to a member.   The seat load detection device according to claim 1, further comprising a connection fixing member that connects the action support members of the first to fourth load sensors.

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