DOOR HANDLE APPARATUS

A door handle apparatus to be attached to a door of a vehicle is provided. The door handle apparatus includes a case, a strain body, and an elastic mechanism. The case includes an outer case provided so as to face a vehicle exterior side and an inner case provided so as to face a vehicle interior side. The outer case and the inner case are integrated with each other. The strain body is provided in the case, has a sensor mounted on a middle portion between one end portion and an opposite end portion of the strain body, and the one end portion of the strain body is fixed to a portion on a center side of the inner case. The elastic mechanism uses an elastic force to press the opposite end portion of the strain body against a fixing portion at an end of the inner case.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a door handle apparatus.

2. Description of the Related Art

For example, Patent Document 1 discloses a technique for unlocking or locking a door of a vehicle by detecting deformation of a substrate in a vehicle door handle with a pressure sensor, provided on the substrate in the door handle, when pressure is applied to the door handle.

Patent Documents

SUMMARY OF THE INVENTION

According to an embodiment, a door handle apparatus to be attached to a door of a vehicle is provided. The door handle apparatus includes a case, a strain body, and an elastic mechanism. The case includes an outer case provided so as to face a vehicle exterior side and an inner case provided so as to face a vehicle interior side. The outer case and the inner case are integrated with each other. The strain body is provided in the case, has a sensor mounted on a middle portion between one end portion and an opposite end portion of the strain body, and the one end portion of the strain body is fixed to a portion on a center side of the inner case. The elastic mechanism is configured to use an elastic force to press the opposite end portion of the strain body against a fixing portion at an end of the inner case.

DESCRIPTION OF THE EMBODIMENTS

In the technique disclosed in Patent Document 1, because deformation of the substrate provided at the center in the longitudinal direction of the door handle is detected, the amount of deformation is relatively small, and thus, it is difficult to more securely detect pressure applied to the door handle.

In view of the above, the inventors of the present invention have found that there is a need for a technique by which pressure applied to the inner side of a door handle can be more securely detected. In particular, the inventors of the present invention have found that there is a need for a technique by which, while a strain sensor configured to detect a load applied to a door handle is employed, damage to the strain sensor can be prevented even if a significantly large load is applied to the door handle.

In the following, embodiments will be described with reference to the accompanying drawings. In the drawings, for the sake of convenience, a Z-axis direction (direction corresponding to the height direction of a vehicle) is referred to as a vertical direction, a Y-axis direction (direction corresponding to the width direction of the vehicle) is referred to as a lateral direction, and an X-axis direction (direction corresponding to the lengthwise direction of the vehicle) is referred to as a longitudinal direction. Further, in the drawings, a positive Y-axis side is referred to as an outer side or a vehicle exterior side, and a negative Y-axis side is referred to as an inner side or a vehicle interior side.

(Overview of Door Handle Apparatus100)

FIG.1is a perspective view of the exterior of a door handle apparatus100according to an embodiment as viewed from the vehicle exterior side.FIG.2is a perspective view of the exterior of the door handle apparatus100according to the embodiment as viewed from the vehicle interior side. As illustrated inFIG.1andFIG.2, the door handle apparatus100is an elongated rod-shaped component extending along the longitudinal direction (X-axis direction) of the vehicle. The door handle apparatus100is a component that is attached to a vehicle-exterior-side surface20A (seeFIG.3) of a door20of the vehicle and is held by a user when the user opens and closes the door20.

As illustrated inFIG.1andFIG.2, the door handle apparatus100includes a case100A. The case100A forms the external shape of the door handle apparatus100. The case100A may be formed of a resin material such as an acrylonitrile butadiene styrene (ABS) resin or a polycarbonate (PC) resin. The case100A has an inner case110on the vehicle interior side (negative Y-axis side) and an outer case120mainly on the vehicle exterior side (positive Y-axis side). Both the inner case110and the outer case120have an elongated shape extending in the longitudinal direction (X-axis direction) of the vehicle. The case100A is formed by integrating the inner case110and the outer case120with each other.

As illustrated inFIG.2, an opening120B extending in the longitudinal direction (X-axis direction) is formed in a vehicle-interior-side surface120A provided on the vehicle interior side (negative Y-axis side) of the outer case120. The opening120B has approximately the same shape as the outer shape of the inner case110. The inner case110is fitted into the opening120B.

A recess100B that is recessed toward the vehicle exterior side (positive Y-axis side) is formed in the center on the vehicle interior side (negative Y-axis side) and in the longitudinal direction (X-axis direction) of the door handle apparatus100. Two flat installation surfaces100C are provided at respective end portions on the vehicle interior side (negative Y-axis side) and in the longitudinal direction (X-axis direction) of the door handle apparatus100.

FIG.3is a diagram illustrating an installation state of the door handle apparatus100according to the embodiment. As illustrated inFIG.3, the door handle apparatus100is screwed and fixed to the door20, with the installation surfaces100C being in contact with the vehicle-exterior-side surface20A of the door20.

As illustrated inFIG.3, because the door handle apparatus100has the recess100B, a space (seeFIG.3) that allows the user's hand to be inserted between the vehicle-exterior-side surface20A of the door20and the door handle apparatus100is formed. Therefore, the door handle apparatus100can be held by the user's hand.

(Internal Configuration of Door Handle Apparatus100)

FIG.4is an exploded perspective view of the door handle apparatus100according to the embodiment.FIG.5is a cross-sectional view of the door handle apparatus100according to the embodiment. InFIG.5, a cross section of the XY plane as viewed from an approximately oblique angle in the positive X-axis direction and in the positive Y-axis direction is depicted.

As illustrated inFIG.4, the case100A of the door handle apparatus100can be divided into the inner case110and the outer case120. The inner case110is integrated with the outer case120by being fitted into the opening120B formed in the outer case120and having approximately the same shape as the inner case110. The inner case110includes a holding portion111, a fixing portion112, and a fixing portion113.

The holding portion111is a portion provided at the center in the longitudinal direction (X-axis direction) of the inner case110and having an elongate shape extending in the longitudinal direction (the X-axis direction). The holding portion111is a portion to which a load is applied by the user's hand in a direction toward the outside of the vehicle (in the positive Y-axis) when the user opens the door20. A vehicle-exterior-side surface111A on the vehicle exterior side (positive Y-axis side) of the holding portion111has a flat shape. A capacitance sensor140is provided on the vehicle-exterior-side surface111A. The capacitance sensor140has a thin, flat, rectangular shape and is elongated in the longitudinal direction (X-axis direction) as viewed from the vehicle exterior side in a plan view. The capacitance sensor140includes a detection electrode, and when the user's hand contacts the inner side of the door handle apparatus100, the capacitance sensor140outputs a current value corresponding to the capacitance of the detection electrode as a contact detection signal. A vehicle-interior-side surface111B of the holding portion111has a curved shape extending along the recess100B (seeFIG.1throughFIG.3) of the door handle apparatus100, and forms a part of the recess100B. The thickness of the holding portion111in the left-right direction (the Y-axis direction) decreases from both ends toward the center of the holding portion111in the longitudinal direction (the X-axis direction). Therefore, the both ends of the holding portion111have high rigidity and are less likely to deform.

The fixing portion112is a portion provided at a front end portion of the inner case110(at the end on the front side of the vehicle) in the longitudinal direction (the X-axis direction) and fixed to the outer case120. The fixing portion112is a portion having approximately a flat plate shape and extending forward (toward the positive X-axis side) from a front end portion of the holding portion111. The fixing portion112includes a pedestal portion112A that is spaced apart from the front end portion of the holding portion111. Therefore, in the fixing portion112, a recess114, which is partially recessed toward the vehicle interior side (negative Y-axis side), is formed between the holding portion111and the pedestal portion112A. Further, the bottom surface of the recess114in the fixing portion112serves as a thin portion112B that is thinner than the surrounding portions (the holding portion111and the pedestal portion112A). Accordingly, the inner case110is readily elastically deformed locally in the thin portion112B when a load is applied to the holding portion111. A screw-fixing portion112C is formed in the pedestal portion112A of the fixing portion112, and the fixing portion112is fixed to the outer case120by a screw through the screw-fixing portion112C.

The fixing portion113is a portion provided at a rear end portion of the inner case110(at the end on the rear side of the vehicle) in the longitudinal direction (the X-axis direction) and fixed to the outer case120. The fixing portion113has a symmetrical shape with the fixing portion112with respect to the YZ plane. The fixing portion113is a portion having approximately a flat plate shape and extending rearward (toward the negative X-axis side) from a rear end portion of the holding portion111. The fixing portion113includes a pedestal portion113A that is spaced apart from the rear end portion of the holding portion111. Therefore, in the fixing portion113, a recess115, which is partially recessed toward the vehicle interior side (negative Y-axis side), is formed between the holding portion111and the pedestal portion113A. Further, the bottom surface of the recess115in the fixing portion113serves as a thin portion113B that is thinner than the surrounding portions (the holding portion111and the pedestal portion113A). Accordingly, the inner case110is readily elastically deformed locally in the thin portion113B when a load is applied to the holding portion111. A screw-fixing portion113C is formed in the pedestal portion113A of the fixing portion113, and the fixing portion113is fixed to the outer case120by a screw through the screw-fixing portion113C.

<Detailed Configuration of Vicinity of Front End Portion of Inner Case110>

A detailed configuration of the vicinity of a front end portion of the inner case110will be described with reference toFIG.6andFIG.7.FIG.6is a partially enlarged perspective view of the vicinity of a front end portion of the door handle apparatus100according to the embodiment.FIG.7is a partially enlarged cross-sectional view of the vicinity of the front end portion of the door handle apparatus100according to the embodiment.

As illustrated inFIG.6andFIG.7, in the vicinity of the front end portion of the inner case110, the recess114is formed between the holding portion111and the pedestal portion112A as described above. Further, the bottom surface of the recess114serves as the thin portion112B that is thinner than the surrounding portions (the holding portion111and the pedestal portion112A).

An opening on the vehicle exterior side of the recess114is closed by a strain body116. The strain body116is a flat-plate-shaped member that is approximately parallel to the XZ plane. The strain body116may be formed of, for example, a resin material or a metal material. A rear end portion of the strain body116is fixed to the vehicle-exterior-side surface111A, which is a surface on the vehicle exterior side of the holding portion111, by two fixing screws117.

In the present embodiment, the strain body116includes a first flat plate portion116A (an example of a “flat plate portion”) and a second flat plate portion116B (an example of a “connecting portion”) whose positions in the Y-axis direction differ from each other. However, the configuration of the strain body116is not limited thereto, and the strain body116may include one flat plate portion.

The first flat plate portion116A is a flat plate portion that is approximately at the same height as the vehicle-exterior-side surface111A of the holding portion111, extends forward (in the positive X-axis direction) relative to the vehicle-exterior-side surface111A, and covers the opening on the vehicle exterior side of the recess114. The rear end portion of the first flat plate portion116A (that is, the rear end of the strain body116) is fixed to the vehicle-exterior-side surface111A by the two fixing screws117. A strain sensor130is provided on a surface116Aa on the vehicle exterior side of the first flat plate portion116A.

The strain sensor130includes a flexible printed circuit (FPC) and four strain detection elements132. The FPC131is a thin film-shaped wiring member that is bonded to the surface116Aa by an adhesive, a double-sided tape, or the like. The four strain detection elements132are arranged on the same circumference at 90° intervals on the surface of the FPC131. The resistance values of the four strain detection elements132change according to the amount of distortion of the first flat plate portion116A, thereby allowing the strain detection elements132to detect the amount of distortion of the first flat plate portion116A. The strain sensor130detects the amount of distortion of the first flat plate portion116A by the four strain detection elements132, and outputs a strain detection signal indicating the amount of distortion as a load detection signal indicating that a load is applied by the user's hand. Note that the number of strain detection elements132may be two or three or more.

The second flat plate portion116B is a portion that overlaps a part of the first flat plate portion116A at a position offset toward the vehicle interior side (negative Y-axis side) relative to the first flat plate portion116A, and that has a flat plate shape extending in the longitudinal direction (the X-axis direction). A front end portion of the second flat plate portion116B contacts a vehicle-exterior-side surface112Aa on the vehicle exterior side of the pedestal portion112A, and is pressed against the vehicle-exterior-side surface112Aa by an elastic mechanism150as will be described later. A rear end portion of the second flat plate portion116B is bent in an L-shape, and a square-pillar-shaped-portion thereof, whose center axis passes through the center of the four strain detection elements132, is connected to the back surface (surface on the vehicle interior side) of the first flat plate portion116A.

The elastic mechanism150is provided on the vehicle exterior side of the pedestal portion112A. The elastic mechanism150includes a shaft151and a coil spring152. The shaft151is a rod-shaped member having a large diameter. The shaft151is provided perpendicularly to the second flat plate portion116B of the strain body116and the vehicle-exterior-side surface112Aa of the pedestal portion112A. The shaft151passes through the second flat plate portion116B of the strain body116, and the second flat plate portion116B is guided by the shaft151so as to be movable in the Y-axis direction. An end portion151A of the shaft151is embedded in and fixed to the vehicle-exterior-side surface112Aa of the pedestal portion112A. An end portion151B of the shaft151has a large diameter, and is formed in a disc shape having a diameter larger than the outer diameter of the coil spring152such that the coil spring152does not fall off. For example, a bolt or the like may be used as the shaft151.

The coil spring152is provided between the second flat plate portion116B of the strain body116and the end portion151B on the vehicle exterior side of the shaft151in a compressed state so as to be elastically deformable in the Y-axis direction. The shaft151passes through the center of the coil spring152. The coil spring152uses an elastic force to preload the second flat plate portion116B of the strain body116toward the vehicle interior side. Accordingly, the elastic mechanism150presses the second flat plate portion116B of the strain body116against the vehicle-exterior-side surface112Aa of the pedestal portion112A.

(Operation of Door Handle Apparatus)

FIG.8andFIG.9are diagrams illustrating the operation of the door handle apparatus100according to the embodiment. In the following, the operation of the door handle apparatus100when a load is applied to the holding portion111of the inner case110by the user's hand in a direction toward the outside of the vehicle (in the positive Y-axis direction) (as indicated by an arrow A inFIG.8andFIG.9) will be described with reference toFIG.8andFIG.9.

In this case, the holding portion111of the inner case110is elastically deformed according to the rigidity of the holding portion111, which is set according to the material, the shape, and the like of the holding portion111, and is displaced toward the outside of the vehicle by the elastic deformation (as indicated by an arrow B inFIG.8andFIG.9). However, because the pedestal portion112A of the inner case110has high rigidity and is fixed to the outer case120, the pedestal portion112A is not displaced. Therefore, in the inner case110, the thin portion112B between the holding portion111and the pedestal portion112A is locally elastically deformed so as to deflect toward the outside of the vehicle (as indicated by an arrow C inFIG.8andFIG.9). Note that, in practice, a side wall (a front end surface111C) at the end in the X direction of the holding portion111, which defines the recess114, is tilted by elastic deformation of the thin portion112B; however, because the effect is small, the description thereof will be omitted.

As described above, the rear end portion of the strain body116(first flat plate portion116A) is fixed to the vehicle-exterior-side surface111A of the holding portion111. In addition, the front end portion of the strain body116(second flat plate portion116B) is pressed against the pedestal portion112A by the elastic mechanism150.

Therefore, as illustrated inFIG.8, when a load less than a predetermined value is applied to the holding portion111of the inner case110in a direction toward the outside of the vehicle, the rear end portion of the strain body116is displaced toward the outside of the vehicle (as indicated in an arrow D inFIG.8), but the front end portion of the strain body116(second flat plate portion116B) remains pressed against the pedestal portion112A by the elastic mechanism150. As a result, distortion occurs in a middle portion of the strain body116(including a portion, covering the recess114, of the first flat plate portion116A, and a portion, covering the recess114, of the second flat plate portion116B) (as indicated in arrows E inFIG.8), and the distortion in the first flat plate portion116A is detected by the strain sensor130. In this case, the distortion in the middle portion of the strain body116is relatively small and does not damage the strain sensor130.

That is, in the door handle apparatus100according to the embodiment, because the inner case110includes an elastic member, the amount of displacement in the strain body116can be decreased as compared to the amount of displacement in the holding portion111by disposing the strain body116at the end portion on the fixing portion112side of the inner case110in the longitudinal direction. In addition, in the door handle apparatus100according to the embodiment, the required amount of displacement can also be secured by forming the thin portion112B. In the door handle apparatus100according to the embodiment, by appropriately setting the material and the shape of the inner case110, the shape and the installation position of the strain body116, and the like, the amount of displacement in the strain body116is controlled such that one-tenth of a load applied to the holding portion111is measured. In the door handle apparatus100according to the embodiment, both the second flat plate portion116B and the first flat plate portion116A are deformed; however, the first flat plate portion116A may be mainly deformed.

Further, as illustrated inFIG.9, when a load greater than the predetermined value is applied to the holding portion111of the inner case110in a direction toward the outside of the vehicle, the rear end portion of the strain body116is displaced toward the outside of the vehicle (as indicated in an arrow D inFIG.9), and distortion occurs in a middle portion of the strain body116(as indicated in an arrow E inFIG.9). In addition, the front end portion of the strain body116(second flat plate portion116B) is also displaced toward the outside of the vehicle (as indicated in an arrow F inFIG.9). This is because the force by which the front end portion of the strain body116(second flat plate portion116B) pushes the coil spring152toward the outside of the vehicle overcomes the preload force of the coil spring152toward the inside of the vehicle. Accordingly, the amount of distortion in the middle portion of the strain body116can be reduced to the extent that the strain sensor130is not damaged.

The door handle apparatus100according to the embodiment is configured such that, when a load α is applied to the holding portion111(when the holding portion111is held by the user's hand with a relatively large force), a load β that is, for example, approximately one-tenth of the load α is applied to the strain sensor130as described above. That is, the spring constant of the coil spring152is designed such that the load β is reduced to the extent that the strain sensor130is not damaged (that is, the spring constant of the coil spring152is designed such that the second flat plate portion116B compresses and moves the coil spring152toward the outside of the vehicle before the load β reaches the upper limit value).

Further, in the door handle apparatus100according to the embodiment, the capacitance sensor140detects the contact of the user's hand with the inner side of the door handle apparatus100, or detects a position in the X direction of the inner side of the door handle apparatus100where the user's hand contacts. Further, in response to the user's hand pulling the door handle apparatus100, the door handle apparatus100according to the embodiment detects a load applied to the strain sensor130by using the four strain detection elements132of the strain sensor130. Then, if the load applied to the door handle apparatus100is greater than a predetermined value, the door handle apparatus100determines that the user has performed a pulling action. Note that a threshold for determining that the user has performed a pulling action is set within a load range in which the second flat plate portion116B remains pressed against the pedestal portion112A by the elastic mechanism150. Further, calculation methods such as a contact detection method and a load detection method are known techniques, and thus, detailed descriptions thereof will not be provided.

As described above, the door handle apparatus100according to the embodiment is the door handle apparatus100to be attached to the door20of the vehicle, and includes a case A, the strain body116, and the elastic mechanism150. The case A is formed by integrating the outer case120provided on the vehicle exterior side with the inner case110provided on the vehicle interior side. The strain body116is provided in the case A, the strain sensor130is mounted between one end portion and the other end portion of the strain body116, and the one end portion of the strain body116is fixed to a portion on the center side of the inner case110. The elastic mechanism150is configured to use an elastic force to press the other end portion of the strain body116against the fixing portion112at the end of the inner case110.

Accordingly, when a load is applied to the inner case110in a direction toward the outside of the vehicle, the door handle apparatus100according to the embodiment can cause local distortion in the middle portion between the one end portion and the other end portion of the strain body116. Therefore, the door handle apparatus100according to the embodiment can securely detect the load applied to the inner case110(that is, applied to the inner side of the door handle apparatus100) by detecting the local distortion in the middle portion of the strain body116, using the strain sensor130.

Further, in the door handle apparatus100according to the embodiment, when a load greater than a predetermined value is applied to the inner case110in a direction toward the outside of the vehicle, the other end portion of the strain body116can be displaced toward the outside of the vehicle against the preload force of the elastic mechanism150. Therefore, the door handle apparatus100according to the embodiment can reduce the amount of distortion in the middle portion of the strain body116, and thus, prevent the strain sensor130from being damaged.

Further, in the door handle apparatus100according to the embodiment, the second flat plate portion116B of the strain body116is offset toward the vehicle interior side relative to the first flat plate portion116A. Therefore, a sufficient space to dispose the elastic mechanism150can be secured on the vehicle exterior side of the second flat plate portion116B.

In the present embodiment, the second flat plate portion116B of the strain body116is elastically pressed against the fixing portion112by the elastic mechanism150; however, the first flat plate portion116A may be elastically pressed by the elastic mechanism150. In this case, a more complicated structure than that of the present embodiment would be required because a surface for receiving the rear end portion of the first flat plate portion116A would need to be provided on the positive Y-axis side of the holding portion111, and further, the elastic mechanism150would need to be provided on the negative Y-axis side so as to elastically press the first flat plate portion116A toward the positive Y-axis side.

FIG.10is a partially enlarged perspective view of the vicinity of a front end portion of a door handle apparatus100-2according to a first modification.FIG.11is a partially enlarged cross-sectional view of the vicinity of the front end portion of the door handle apparatus100-2according to the first modification. The door handle apparatus100-2according to the first modification illustrated inFIG.10andFIG.11includes a strain body118instead of the strain body116.

The strain body118includes a base portion118A, a pillar portion118B, a flat plate portion118C, and an arm portion118D. The strain body118is formed of a resin material.

The base portion118A is an L-shaped portion that is bent at a right angle at the front corner of the holding portion111(a right-angle corner formed by the vehicle-exterior-side surface111A and the front end surface111C). The base portion118A includes a horizontal portion118Aa extending along the vehicle-exterior-side surface111A and a vertical portion118Ab (an example of a “flat plate portion”) extending along the front end surface111C. The horizontal portion118Aa of the base portion118A is fixed to the vehicle-exterior-side surface111A by two fixing screws117.

As illustrated inFIG.11, in the door handle apparatus100-2, the FPC131of the strain sensor130is bent at a right angle and is disposed along the base portion118A. The four strain detection elements132of the strain sensor130are fixed to the back surface (the surface on the negative X-axis side) of the vertical portion118Ab. The four strain detection elements132are arranged on the same circumference, with the pillar portion118B being centered, at 90° intervals as viewed from the front in a plan view.

In the example illustrated inFIG.11, the FPC131is disposed along the back surface of the vertical portion118Ab of the base portion118A and along the front surface of the horizontal portion118Aa of the base portion118A. That is, the FPC131is exposed from the horizontal portion118Aa of the base portion118A. However, the FPC131may be disposed along the back surface of the horizontal portion118Aa so as not to be exposed from the horizontal portion118Aa of the base portion118A.

The pillar portion118B is a square-pillar-shaped portion that protrudes forward (in the positive X-axis direction) from the center of the vertical portion118Ab. The flat plate portion118C is a flat plate-shaped portion and is stacked on the vehicle-exterior-side surface112Aa of the pedestal portion112A. The flat plate portion118C is pressed against the vehicle-exterior-side surface112Aa by the elastic mechanism150. The arm portion118D connects a rear end portion of the flat plate portion118C to a front end portion (a corner portion on the vehicle exterior side) of the pillar portion118B. In the first modification, the pillar portion118B, the arm portion118D, and the flat plate portion118C correspond to a “connecting portion”.

In the door handle apparatus100-2according to the first modification, when a load is applied to the holding portion111of the inner case110by the user's hand in a direction toward the outside of the vehicle (in the positive Y-axis direction), the thin portion112B of the inner case110is locally elastically deformed so as to deflect toward the outside of the vehicle (as indicated by an arrow A inFIG.11) as described above.

As described above, the base portion118A of the strain body118is fixed to the vehicle-exterior-side surface111A of the holding portion111. In addition, the flat plate portion118C of the strain body118is pressed against the vehicle-exterior-side surface112Aa of the pedestal portion112A by the elastic mechanism150.

Therefore, in the door handle apparatus100-2according to the first modification, when a load less than a predetermined value is applied to the holding portion111of the inner case110in a direction toward the outside of the vehicle, the base portion118A of the strain body118is displaced toward the outside of the vehicle (as indicated by an arrow B inFIG.11), but the flat plate portion118C of the strain body118remains pressed against the pedestal portion112A by the elastic mechanism150. As a result, distortion occurs in a middle portion (including the pillar portion118B, the arm portion118D, and the vertical portion118Ab) of the strain body118(as indicated by an arrow C inFIG.11), and the distortion is detected by the strain sensor130. In this case, the distortion in the middle portion of the strain body118is relatively small and does not damage the strain sensor130.

Further, in the door handle apparatus100-2according to the first modification, when a load greater than the predetermined value is applied to the holding portion111of the inner case110in a direction toward the outside of the vehicle, the base portion118A of the strain body118is displaced toward the outside of the vehicle (as indicated by the arrow B inFIG.11), and distortion occurs in the middle portion of the strain body118(as indicated by the arrow C inFIG.11). In addition, the flat plate portion118C of the strain body118is also displaced toward the outside of the vehicle (as indicated by an arrow D inFIG.11). This is because the force by which the flat plate portion118C of the strain body118pushes the coil spring152toward the outside of the vehicle overcomes the preload force of the coil spring152toward the inside of the vehicle. Accordingly, the amount of distortion in the middle portion of the strain body118can be reduced to the extent that the strain sensor130is not damaged.

(Example of Additional Configuration of Strain Body116)

FIG.12is a diagram illustrating an example of an additional configuration of the strain body116. In the example illustrated inFIG.12, the strain body116includes a first spherical portion116C and a second spherical portion116D.

The first spherical portion116C is provided at the rear end portion of the first flat plate portion116A of the strain body116. The first spherical portion116C is constituted by hemispherical-shaped portions that protrude toward the vehicle exterior side (positive Y-axis side) and the vehicle interior side (negative Y-axis side) relative to the first flat plate portion116A. A fixing screw117passes through the first spherical portion116C. With the first flat plate portion116A being tilted, the first spherical portion116C allows the first flat plate portion116A to be fixed to the vehicle-exterior-side surface111A by the fixing screw117.

The second spherical portion116D is provided at the front end portion of the second flat plate portion116B of the strain body116. The second spherical portion116D is constituted by hemispherical-shaped portions that protrude toward the vehicle exterior side (positive Y-axis side) and the vehicle interior side (negative Y-axis side) relative to the second flat plate portion116B. The shaft151passes through the second spherical portion116D. With the second flat plate portion116B being tilted, the second spherical portion116D allows the second flat plate portion116B to be pressed against the vehicle-exterior-side surface112Aa by the coil spring152.

According to the strain body116illustrated inFIG.12, even when the strain body116is tilted due to the difference in height between the vehicle-exterior-side surface111A and vehicle-exterior-side surface112Aa, the tilt of the strain body116can be allowed by the first spherical portion116C and the second spherical portion116D. That is, according to the strain body116illustrated inFIG.12, with the strain body116being tilted, the one end portion of the strain body116can be fixed to the vehicle-exterior-side surface111A and the other end portion of the strain body116can be pressed against the vehicle-exterior-side surface112Aa of the strain body116without the strain body116being distorted.

According to an embodiment, a load applied to the inner side of a door handle can be more securely detected, and damage of a strain sensor can be prevented even if a significantly large load is applied to the door handle.

Although specific embodiments have been described above, the present invention is not limited to the above-described embodiments. Variations and modifications may be made to the described subject matter without departing from the scope of the invention as set forth in the accompanying claims.

For example, the strain body does not necessarily have the shape described in the embodiment. That is, the strain body may have any shape as long as the strain sensor is mounted on a middle portion between one end portion and the other end portion of the strain body, the one end portion of the strain body is fixed to a portion on the center side of the inner case, and the other end portion of the strain body is pressed against the fixing portion at the end of the inner case.

Further, the elastic member is not necessarily the coil spring, and any other elastic member (such as rubber) may be used.