The present application is based on Japanese patent application No. 2018-088826 filed on May 2, 2018, the entire contents of which are incorporated herein by reference.
The present invention relates to a pinch detection switch for detecting pinching in a movable body such as a door closing and open portion in a vehicle such as an automobile.
Conventionally, a pinch detection switch for detecting pinching is disposed in an end portion on a forward side in a moving direction of a movable body such as a slidable door of an automobile which can pinch a human body or baggage thereof (see e.g. JP-A-2014-216300).
A pinch detection switch (so-called “cord switch”) described in JP-A-2014-216300 includes a cord switch main body, and a member to be attached, which functions as a bracket for fixing the cord switch main body to the slidable door. The cord switch body comprises a hollow tubular member having elasticity and insulation properties, a plurality of conductor wires spaced apart from each other and opposed to an inner surface of the tubular member, and a cord cover, which covers the tubular member.
The cord cover has a tubular shape in which a hollow portion which receives the tubular member is formed in a center portion, and a tubular member holding a conductor wire is inserted in that hollow portion. When the cord cover collides with a pinched object (for example, a human body) to be detected during forward movement in the moving direction (closing direction) of the slide door, the conductor wires held by the tubular member come into contact with each other due to the pressure caused by the collision, so the electric resistance between the conductor wires varies. The occurrence of pinching can then be detected by this change in electrical resistance.
In the pinch detection switch described in JP-A-2014-216300, at the time of assembly, it is necessary to insert the tubular member into a hollow portion of the cord cover over substantially the entire length of the cord cover. This work is difficult. Further, when the cord cover is sufficiently large as compared with the tubular member and no large frictional force is caused between the inner surface of the hollow portion and the outer circumferential surface of the tubular member, it is possible to easily insert the tubular member into the hollow portion, but, in this case, the position of the tubular member within the hollow portion becomes unstable, and it may be impossible to detect an appropriate pinching.
It is therefore an object of the present invention to provide a pinch detection switch, which is easy to assemble, and capable of properly performing pinch detection.
In order to solve the above-described problems, the present invention provides a pinch detection switch, comprising: a pressure sensing structure including at least one linear pressure sensing member with a plurality of conductor wires spaced apart from each other in an inner side of a tubular elastic body; and a tubular cover member to be attached to an end portion on a forward side in a moving direction of a movable body, the tubular cover member being formed with a hollow portion which receives the pressure sensing structure, wherein the pressure sensing structure includes a coating member which covers the at least one linear pressure sensing member, and which is opposed to an inner surface of the hollow portion at both its end portions in a width direction at right angles to the moving direction of the movable body and an extending direction of the cover member, wherein a position in the width direction of the at least one linear pressure sensing member in the hollow portion is defined by the coating member.
The pinch detection switch according to the present invention is easy to assemble, and makes it possible to properly perform pinch detection.
This vehicle 1 has a vehicle body 10 and a slidable door 11 that can open and close a door open portion 100 formed in the vehicle body 10. The slidable door 11 is guided to an upper guide rail 101 and a lower guide rail 102 and is moved in the front and rear directions of the vehicle 1 by the driving force of an electric motor. When the slidable door 11 is moved to the front of the vehicle 1, the door open portion 100 is closed. The slidable door 11 is an embodiment of a movable body of the present invention. Further, in the following description, the front direction of the vehicle, which is the closing direction, will be described as the forward direction of the moving directions.
In the end portion on the forward side in the moving direction of the slide door 11, a pinching detection switch 2 is extended and disposed along a vehicle vertical direction. When the pinch detection switch 2 comes in contact with a human body or baggage pinched to be detected when the slidable door 11 is closed, that contact is detected by a control device, and the control device stops or reverses the electric motor. This makes it possible to prevent the object to be detected from being strongly pinched between the slidable door 11 and the vehicle body 10.
The pinch detection switch 2 includes a pressure sensing structure 3 having a linear pressure sensing member 31, a coating member 32 covering the linear pressure sensing member 31 and a tubular cover member 4 having a hollow portion 40 for receiving the pressure sensitive structure 3. In the present embodiment, the pressure sensing structure 3 is in the shape of a belt (a circular arc in
In the present embodiment, the coating member 32 covers the three linear pressure sensing members 31 together. When the direction at right angles to the extending direction of the cover member 4 and the moving direction of the slidable door 11 is taken as the width direction of the coating member 32, the three linear pressure sensing members 31 are equally spaced apart in that width direction. In
In the following description, when it is necessary to distinguish each of the three linear pressure sensing members 31 of the pressure sensing structure 3, the pressure sensing member 31 disposed in a middle portion 3a in the width direction of the pressure sensitive structure 3 will be described as the a first linear pressure sensing member 31A, and the other two linear pressure sensing members 31 will be described as a second linear pressure sensing member 31B and a third linear pressure sensing member 31C. The second and third linear pressure sensing members 31B and 31C are arranged in both width direction end portions 3b and 3c in both width direction sides, respectively, of the middle portion 3a in the width direction of the pressure sensing structure 3.
The cover member 4 integrally includes a base portion 41 fixed to an attachment portion 111 provided in an end portion on the forward side in the moving direction of the slide door 11, a cover portion 42 provided on the forward side in the moving direction relative to the base portion 41, to form the hollow portion 40 between it and the base portion 41, and a protruding portion 43 provided to be protruded from the base portion 41 toward the cover portion 42. The cover member 4 and the coating member 32 are made of, for example, urethane rubber, EP rubber, silicone rubber, styrene butadiene rubber, chloroprene rubber, olefin based or styrene based thermoplastic elastomer, urethane resin or the like, and they have elasticity to be deformed by pressing force caused by contact with the object to be detected.
The protruding portion 43 faces the middle portion 3a in the width direction of the pressure sensing structure 3 in the moving direction of the slidable door 11. In other words, the middle portion 3a in the width direction of the pressure sensing structure 3 and the protruding portion 43 are aligned in the moving direction of the slidable door 11. Also, the protruding portion 43 is protruded from the end face 41a on the forward side in the moving direction of the base portion 41 toward the cover portion 42, and the cross section shown in
Hereinafter, the tip surface in the protruding direction of the protruding portion 43 will be referred to as the top surface 43a, and the surfaces on both sides thereof will be described as the side surfaces 43b. The top surface 43a corresponds to a trapezoidal upper base, and both the side surfaces 43b correspond to trapezoidal legs. The top surface 43a and the side surfaces 43b form an obtuse angle in the cross section shown in
The coating member 32 is not fixed to the cover member 4, and the movement of the coating member 32 in the hollow portion 40 is regulated by the end portion 321 in the width direction of the coating member 32 being opposed to the inner surface 40a of the hollow portion 40. The positions of the first to third linear pressure sensing members 31A to 31C in the direction of the arrow B (the width direction of the coating member 32) within the hollow portion 40 are defined by the coating member 32. Of the first to third linear pressure sensing members 31A to 31C, the first linear pressure sensing member 31A is positioned at a position corresponding to the front in the moving direction of the top surface 43a of the protruding portion 43.
That is, for example, even when the pressure sensing structure 3 is acted on by a force in the moving direction in the width direction of the coating member 32 due to contact with the detection target of the pinching detection switch 2, the amount of movement of the pressure sensing structure 3 is restricted by the contact between the end portion 321 in the moving direction in the coating member 32 and the inner surface 40a of the hollow portion 40. In the present embodiment, the width direction dimension of the coating member 32 is configured so that both the end portions 321 and 321 in the width direction of the coating member 32 abut on the inner surface 40a of the hollow portion 40. However, the width direction dimension of the coating member 32 is not limited to this, but may be configured so that when the pressure sensing structure 3 is moved to one side in the width direction of the coating member 32, the end portion 321 in one side in the width direction of the coating member 32 abuts on the inner surface 40a of the hollow portion 40, and when the pressure sensing structure 3 is moved to the other side in the width direction of the coating member 32, the end portion 321 in the other side in the width direction of the coating member 32 abuts on the inner surface 40a of the hollow portion 40.
It should be noted, however, that, as in the present embodiment, when in a normal state where no pinching occurs, both the end portions 321 and 321 in the width direction of the coating member 32 are configured to abut on the inner surface 40a of the hollow portion 40, it is possible to more accurately position the first linear pressure sensing member 31A at a position corresponding to the front in the moving direction of the top surface 43a of the protruding portion 43, to thereby be able to improve the detection accuracy of the pinching. Note that the inner surface 40a of the hollow portion 40 includes the end face 41a on the forward side in the moving direction of the base portion 41 and the inner surface 42a of the cover portion 42.
In the electric circuit 5 configured as described above, when the linear pressure sensing member 31 is pressed to bring the conductor wires 312 into contact with each other, the electric resistance in the line 50 in which the four conductor wires 312 and the resistor 52 are connected in series varies. This change in electrical resistance is detected at the control device 6 as a change in current detected by the ammeter 53, where it is recognized that the linear pressure sensing member 31 has been pressed. When recognizing that the linear pressure sensing member 31 has been pressed during the closing operation of the slidable door 11, the control device 6 stops or reverses the electric motor 7.
Note that in
In this illustrated example, the second linear pressure sensing member 31B is sandwiched between the side surface 43b of the protruding portion 43 and the inner surface 42a of the cover portion 42, and the conductor wires 312 are brought into contact (short circuited) with each other. Then, the pinching in the slidable door 11 is detected by the second linear pressure sensing member 31B.
Note that although not shown, when the object to be detected comes into contact with the cover member 4 along the direction tilted in the direction opposite to the moving direction of the slidable door 11 (the direction of the arrow E indicated by the two-dot chain line in
In the pressure sensing structure 3, the coating member 32 has a flat plate shape in a natural state before being received in the hollow portion 40 of the cover member 4. Then, the pressure sensing structure 3 is inserted into the hollow portion 40 with the coating member 32 being elastically deformed to be curved in an arcuate shape. With both the end portions 321 and 321 in the width direction of the coating member 32 being abutted (elastically abutted) on the inner surface 40a of the hollow portion 40 by the restoring force thereof, and being slid on the inner surface 40a, the coating member 32 is inserted into the hollow portion 40. Note that, in order to suppress the sliding resistance in this case, a lubricant may be applied to the surface of the coating member 32 in sliding contact with the inner surface 40a of the hollow portion 40.
(Modifications)
The first modification shown in
The second modification shown in
In the third modified embodiment shown in
According to the embodiment and its modifications described above, the coating member 32 is interposed between the linear pressure sensing member 31 and the inner surface 40a of the hollow portion 40 in the cover member 4, so that the position of the linear pressure sensing member 31 is defined by the coating member 32. Further, when the pressure sensing structure 3 is inserted into the hollow portion 40 of the cover member 4 during producing of the pinch detection switch 2, the rigidity of the pressure sensing structure 3 in this insertion direction is ensured by the coating member 32, and the ratio of the contact area of the outer surface of the coating member 32 in contact with the inner surface 40a of the hollow portion 40 is limited. Therefore, this work can easily be performed. This makes it easy to assemble, and makes it possible to properly perform pinch detection.
Next, the technical ideas grasped from the above-described embodiments will be described with the aid of reference numerals and the like in the embodiments. It should be noted, however, that each of the reference numerals and the like in the following description does not limit the constituent elements in the claims to the members and the like specifically shown in the embodiments.
[1] A pinch detection switch (2), comprising:
a pressure sensing structure (3) including at least one linear pressure sensing member (31) with a plurality of conductor wires (312) spaced apart from each other in an inner side of a tubular elastic body; and
a tubular cover member (4) to be attached to an end portion on a forward side in a moving direction of a moveable body (slidable door 11), the tubular cover member (4) being formed with a hollow portion (40) which receives the pressure sensing structure (3),
wherein the pressure sensing structure (3) includes a coating member (32) which covers the at least one linear pressure sensing member (31), and which is opposed to an inner surface (40a) of the hollow portion (40) at both its end portions (321, 321) in a width direction at right angles to the moving direction of the movable body (11) and an extending direction of the cover member (4),
wherein a position in the width direction of the at least one linear pressure sensing member (31) in the hollow portion (40) is defined by the coating member (32).
[2] The pinch detection switch (2) according to [1] above, wherein the at least one linear pressure sensing member (31) is disposed in a middle portion (3a) in the width direction of the pressure sensing structure (3),
wherein the cover member (4) includes a protruding portion (43/44) which faces the middle portion (3a) of the pressure sensing structure (3) in the moving direction of the movable body (11).
[3] The pinch detection switch (2) according to [2] above, wherein the pressure sensing structure (3) includes three of the linear pressure sensing members (31), and one (31A) of the three linear pressure sensing members (31) is disposed in the middle portion (3a) and other two (31B, 31C) of the three linear pressure sensing an embers (31) are disposed in both sides, respectively, in the width direction of the middle portion (3a).
[4] The pinch detection switch (2) according to [3] above, wherein the cover member (4) includes a base portion (41) to be fixed to the movable body (11), and a cover portion (42) to be provided on the forward side in the moving direction of the movable body (11) relative to the base portion (41), to form the hollow portion (40) between it and the base portion (41),
wherein the protruding portion (43) is provided to protrude from the base portion (41) toward the cover portion (42),
wherein when a pinched object to be detected comes in contact with the cover member (4) along the moving direction of the movable body (11), the linear pressure sensing member (31A) disposed in the middle portion (3a) is sandwiched between a top surface (43a) of the protruding portion (43) and an inner surface (42a) of the cover portion (42),
wherein when the pinched object to be detected comes into contact with the cover member (4) along a direction tilted with respect to the moving direction of the movable body (11), either one (31B, 31C) of the two linear pressure sensing members (31B, 31C) disposed in both the sides in the width direction of the middle portion (3a) the linear pressure sensing members (31) is sandwiched between a side surface (43a) of the protruding portion (43) and the inner surface (42a) of the cover portion (42).
[5] The pinch detection switch (2) according to [4] above, wherein the pressure sensing structure (3) is curved so as to at least partially cover the top surface (43a) and the side surface (43b) of the protruding portion (43) within the hollow portion (40).
[6] The pinch detection switch (2) according to any one of [1] to [5] above, wherein both the end portions (321, 321) of the coating member (32) of the pressure sensing structure (3) abut on the inner surface (40a) of the hollow portion (40) in a normal state in which no pinching occurs.
[7] The pinch detection switch (2) according to any one of [1] to [6] above, wherein the pressure sensing structure (3) is a molded body in which the at least one linear pressure sensing member (31) is molded with the coating member (32).
Although the embodiment of the present invention has been described above, the embodiment described above does not limit the invention according to the claims. It should also be noted that not all combinations of the features described in the embodiments are indispensable to the means for solving the problem of the invention.
Further, the present invention can appropriately be modified and carried out within the scope not deviating from the spirit thereof. For example, although in the above-described embodiment, there has been described the case in which the coating member 32 is in a flat plate shape in the natural state before being received in the hollow portion 40 of the cover member 4, the coating member 32 may be molded into a curved shape. Further, the shape of the coating member 32 in the natural state is not limited to a flat plate shape, but maybe, for example, a U shape or a V shape which is protruded toward the forward side in the moving direction or the rear side in the moving direction.
Also, with respect to the pressure sensing structure (3), one or more linear pressure sensing members (31) may be structured to be arranged side by side on the adhesive surface side of a wide tape and then sandwiched between that tape and another wide tape. That is, it is a pressure sensing structure with a single or a plurality of linear pressure sensing members (31) arranged between two tapes. In this case, the outer surface shape of the pressure sensing structure is not an elliptical shape in a cross section view as shown in
With this structure, as the pressure sensing structure, in a cross section view, a thick portion in which the linear pressure sensing member is disposed and a non-thick portion in which no linear pressure sensing member is disposed are formed, but this non-thick portion, in other words, the portion where the thickness of the pressure sensing structure is thin is a portion which is easily deformed. That is, this ease of deformation contributes to ease of producing the pinch detection switch.
Further, with respect to the pressure sensing structure (3) having a plurality of the linear pressure sensing members (31), the coating member (32) between the linear pressure sensing members may be provided with a cut (a groove) along the linear pressure sensing members. With this configuration, as the pressure sensing structure, in a cross-sectional view, thick portions where the linear pressure sensing members are disposed and non-thick portions between the linear pressure sensing members are formed, but this non-thick portion, in other words, the portion where the thickness of the pressure sensing structure is thin is a portion which is easily deformed. That is, this ease of deformation contributes to ease of producing the pinch detection switch.
Although the invention has been described with respect to the specific embodiments for complete and clear disclosure, the appended claims are not to be thus limited but are to be construed as embodying all modifications and alternative constructions that may occur to one skilled in the art which fairly fall within the basic teaching herein set forth.
Number | Date | Country | Kind |
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2018-088826 | May 2018 | JP | national |