JP2007271302A - Distortion detection apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a distortion detection apparatus having few mounting members and satisfactory in work efficiency and user-friendliness. <P>SOLUTION: The distortion detection apparatus is provided with a column-like strain element 2 for generating strains due to loads; a resistive element 4, which is arranged in the peripheral surface of the strain element 2 and of which a resistance value changes according to the amount of distortion; and a signal processing circuit connected to the resistive element 4 for detecting the amount of distortion of the strain element 2. The constitution is such that screw parts 10 are arranged in the axial direction of the strain element 2, in such a way as to be on both sides of the strain element 2 and integrate the strain element 2 with the screw parts 10; the screw parts 10 are inserted to a through hole of a mounting part 13 of a seat 12 for vehicles, and a through hole of a supporting part 22 of a floor surface part 14 and helically engaged with a nut 20; and elastic member 15 is interposed between the mounting part 13 and the nut 20. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a strain detection device for measuring a load on a vehicle seat or the like.

  Hereinafter, a conventional strain detection apparatus will be described.

  In FIG. 6, the conventional strain detection apparatus is arranged between a plate-shaped metal strain generating body 32 having a plurality of through holes 31 and the through holes 31 of the strain generating body 32, and has resistance according to the amount of strain. A resistance element 33 whose value changes and a signal processing circuit (not shown) connected to the resistance element 33 are provided.

  For example, if the strain detection device is attached between the vehicle seat and the floor portion, the load of the person sitting on the vehicle seat can be measured. A part of the vehicle seat is inserted into the inner through-hole 31 among the plurality of through-holes 31 provided in the strain-generating body 32 to connect the strain-generating body 32 and the vehicle seat. A part of the floor surface portion is inserted and the strain generating body 32 and the floor surface portion are connected and attached (for example, a part of the vehicle seat or a part of the floor surface portion is used as a screw portion, and the nut is formed via the strain generating body 32. Tighten with and attach). Then, when a load is applied to the vehicle seat, the strain body 32 is distorted and the resistance value of the resistance element 33 changes, and the load can be measured by processing this with a signal processing circuit. In this case, since the strain body 32 is connected to both the vehicle seat and the floor portion, the load in the compression direction and the load in the tension direction can be measured. In the signal processing circuit, four resistance elements 33 are annularly connected to form a Hoyston bridge circuit and input to the signal processing circuit.

  As the shape of the strain generating body 32, there is a cylindrical shape in addition to the plate shape, and both are those in which a strain detecting device is attached by combining a plurality of attachment parts.

As prior art document information related to the invention of this application, for example, Patent Document 1 and Patent Document 2 are known.
JP 2003-240633 A JP-A-6-207865

  The above-described conventional strain detection device has a problem in that a plurality of mounting parts are required for mounting the strain detection device, and the assembly work efficiency and usability are poor.

  SUMMARY OF THE INVENTION The present invention solves the above-described problems, and an object of the present invention is to provide a strain detection device that has few attachment parts and is easy to work and easy to use.

  In order to achieve the above object, the present invention particularly arranges the threaded portion in the axial direction of the strain-generating body so as to sandwich the strain-generating body and integrates the strain-generating body and the threaded portion with each other. The mounting member is tightened and fixed between a tightening member that is inserted into the through hole of the mounting member and screwed into the threaded portion, and the strain generating body. An elastic member is disposed between the strain body or the tightening member and tightened and fixed, and the elastic member is not disposed between the other mounting member and the strain generating body or the tightening member. The load is applied to the threaded portion so that the load direction is perpendicular to the axial direction of the strain body, and the amount of strain due to the bending moment of the strain body is detected. is there.

  With the above configuration, the screw portion is arranged in the axial direction of the strain generating body so as to sandwich the strain generating body, and the strain generating body and the screw portion are integrated with each other. If it connects with a floor surface part, attachment will become easy and work efficiency and usability can be improved.

  In particular, the mounting member is tightened and fixed between a tightening member that is inserted into the through hole of the mounting member and screwed into the threaded portion, and the strain generating body. An elastic member is arranged between the attaching member and fixed by tightening, and the elastic member is not arranged between the other mounting member and the strain generating body or the tightening member, and is fixed by fixing. When a load is applied to the threaded portion so that is perpendicular to the axial direction of the strain generating body and the amount of strain due to the bending moment of the strain generating body is detected, the strain is easily generated and the sensor sensitivity is increased. Can be improved.

  When a load is applied to the threaded portion so that the load direction is perpendicular to the axial direction of the strain generating body, a shear force or bending moment is generated in the strain generating body, but the strain amount due to the shear force Since the amount of strain associated with the bending moment is larger, placing the elastic member only between one mounting member and the strain-generating body or tightening member and tightening and fixing it causes a bending moment in the strain-generating body. Therefore, distortion can be accurately detected.

  Hereinafter, the invention described in all claims of the present invention will be described with reference to the drawings.

  1 is a perspective view of a strain detection device according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of the strain detection device, and FIG. 3 is a seat in which a vehicle seat and a floor portion are connected via the strain detection device. 4 is a side view of the unit, FIG. 4 is an enlarged view of part A of FIG. 3, and FIG. 5 is a front sectional view of part A of FIG.

  1 and 2, a strain detection apparatus according to an embodiment of the present invention includes a columnar strain generating body 2 that generates strain due to a load, and a resistance that is arranged on the outer peripheral surface of the strain generating body 2 according to the amount of strain. A resistance element 4 whose value changes and a signal processing circuit (not shown) that is connected to the resistance element 4 and detects the strain amount of the strain generating body 2 are provided. The strain body 2 is in the shape of a prism having a cavity 8 in the axial direction, the exterior of the strain body 2 is in the shape of a quadrangular prism, and the cavity 8 is cylindrical. The screw part 10 is arranged in a direction orthogonal to the axial direction of the strain generating body 2 so as to sandwich the strain generating body 2, and the strain generating body 2 and the screw part 10 are welded and joined together.

  For example, as shown in FIGS. 3 to 5, if this strain detection device is attached between the vehicle seat 12 and the floor surface portion 14, the load of a person sitting on the vehicle seat 12 can be measured.

  The vehicle seat 12 is provided with an attachment portion 13 as an attachment member at a lower portion thereof, and the attachment portion 13 is provided with a through hole into which the screw portion 10 is inserted. The floor surface portion 14 is provided with a support portion 22 as an attachment member on the floor surface 18, and the support portion 22 is provided with a through hole into which the screw portion 10 is inserted. The axial direction of each through hole of the attachment portion 13 and the support portion 22 is set to be horizontal with respect to the floor surface 18.

  Then, one screw portion 10 is inserted into the through hole of the attachment portion 13 of the vehicle seat 12, and the other screw portion 10 is inserted into the through hole of the support portion 22, and tightened with the nuts 20 that are fastening members. The vehicle seat 12 and the floor surface portion 14 are connected via the strain body 2 and the screw portion 10. At this time, the elastic member 15 is disposed between the one attachment portion 13 and the nut 20, and the attachment portion is fastened and fixed by the nut 20. Between the other attachment portion 13 and the strain body 2 or the nut 20, The elastic member 15 is fastened and fixed without being arranged. The elastic member 15 is a rubber washer and can be easily fitted to the screw portion 10.

  In the above strain detection device, when a load is applied to the vehicle seat 12, the screw portion 10 is arranged so that the load direction is perpendicular to the axial direction of the strain generating body 2 (up and down direction with respect to the floor surface 18). A load is added. At this time, since the elastic member 15 is disposed and fastened and fixed between the one attachment portion 13 and the strain generating body 2, a bending moment is generated in the strain generating body 2 and the strain can be accurately detected. it can. Simply, when a load is applied to the screw portion 10 so that the load direction is perpendicular to the axial direction of the strain generating body 2, the strain is generated due to the shearing force or bending moment of the strain generating body 2. Although the body 2 is distorted, the amount of strain associated with a bending moment having a large amount of strain can be detected by the above configuration.

  In particular, the height between the vehicle seat 12 and the floor surface portion 14 can be reduced by simply selecting the diameter of the strain generating body 2 according to the specifications, and the vehicle seat 12 varies depending on the vehicle type. The seat height can be set low beforehand. That is, it becomes easy to adjust the height of the line of sight of the person sitting on the seating surface.

  Since the screw part 10 is formed so as to sandwich the strain generating body 2 with the above configuration, for example, when the vehicle seat 12 and the floor surface part 14 are connected via the screw part 10, an attachment component is provided. It can be installed with little and simple, improving work efficiency and ease of use.

  In particular, the mounting member is inserted between the nut 20 and the strain body 2 which is a tightening member that is inserted into the through hole of the mounting portion 13 or the support portion 22 that is the mounting member and is screwed into the screw portion 10. The elastic member 15 is disposed between one mounting member and the tightening member to be fastened and fixed, and the other mounting member and the strain body 2 or the tightening member are disposed between the other mounting member and the tightening member. Since the elastic member 15 is fastened and fixed without being arranged, when the load is applied to the screw portion 10 so that the load direction is perpendicular to the axial direction of the strain body 2, the strain body 2 is bent. Sensor sensitivity can be improved by detecting the amount of strain caused by the moment. When a load is applied to the screw portion 10 so that the load direction is perpendicular to the axial direction of the strain generating body 2, a shear force or bending moment is generated in the strain generating body 2. The amount of strain associated with the bending moment is greater than that of the bending moment, and the elastic member 15 is disposed between one mounting member and the strain generating body 2 or the tightening member and is fastened and fixed, whereby the bending moment is generated. 2 can be accurately detected.

  Furthermore, since the strain body 2 and the screw portion 10 are integrated with each other, the breakage at the boundary between the strain body 2 and the screw portion 10 can be suppressed even when a load is applied to the vehicle seat 12. From a few tens of kilograms at the time of weight detection to about 1 ton at the time of vehicle collision detection, breakage at the boundary between the strain generating body 2 and the screw portion 10 can be suppressed without impairing the detection capability, and the vehicle can be destroyed. The breakage at the boundary between the strain body 2 and the screw portion 10 can be suppressed even with a load of several tons.

  The strain body 2 and the threaded portion 10 may be welded and joined together, or members made of the same material may be processed. Examples of the material of the strain body 2 and the screw portion 10 include precipitation hardening stainless steel. When the strain body 2 and the screw portion 10 are made of the same material, SUS630 and the like can be cited. Other examples include SUS301 having austenitic work-hardening properties that are rich in ductility and toughness and excellent in weldability, and ferrite-based SUS430 having good corrosion resistance and weldability. These SUS630, SUS301, and SUS430 are stainless steel standards defined by Japanese Industrial Standards (JIS).

  In the embodiment of the present invention, the elastic member 15 is disposed and fastened and fixed between the one mounting member and the tightening member. However, the elastic member 15 is elastic between the one mounting member and the strain body 2. The member 15 may be arranged and fastened and fixed.

  As described above, the strain detection device according to the present invention has few attachment parts, is easy to install, has good work efficiency and convenience, and can be applied to various devices as a sensor for measuring a load.

Sectional drawing of the distortion | strain detector in one embodiment of this invention Cross section of the strain detector Side view of a seat unit in which a vehicle seat and a floor surface portion are connected via the strain detection device Enlarged view of part A in FIG. Front sectional view of part A in FIG. Top view of a conventional strain detector

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 Strain body 4 Resistive element 8 Cavity 10 Screw part 12 Vehicle seat 14 Floor surface part 16 Rail part 18 Floor surface 20 Nut 22 Support part

Claims (5)

A columnar strain generating body that generates strain due to a load; and a resistance element that is disposed on a peripheral surface of the strain generating body and has a resistance value that varies depending on the amount of strain, and the strain generating body sandwiching the strain generating body A screw member disposed in the axial direction, and the strain body and the screw part are integrated with each other, and the screw member is inserted into the through hole of the attachment member and screwed into the screw part; The mounting member is fastened and fixed to the strain generating body, and an elastic member is disposed between the mounting member and the strain generating body or the tightening member to fasten and fix the other. The elastic member is not disposed between the mounting member and the strain generating body or the tightening member, and is fastened and fixed so that the load direction is perpendicular to the axial direction of the strain generating body. A strain detection device that detects a strain amount caused by a bending moment of the strain body by applying a load to the screw portion. The strain detection device according to claim 1, wherein the strain generating body and the screw portion are welded and joined together. The strain detection device according to claim 1, wherein the strain generating body is a cylindrical shape having a cavity in the axial direction. The strain detection apparatus according to claim 1, wherein a load is applied to the screw portion so that a load direction is an axial direction of the strain generating body, and a strain amount due to the axial force of the strain generating body is detected. The strain detection apparatus according to claim 1, wherein the elastic member is a washer.

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