JP2023119665A - touch sensor - Google Patents

Abstract

To provide a touch sensor which can detect contact with an object reliably and quickly.MEANS FOR SOLVING THE PROBLEM: A touch sensor 40 includes: a cylinder part 41 which is elastically deformed by external force generated by contact of an object 50; a flexible material part 42 which has flexibility higher than that of a material forming the cylinder part 41 and fills the cylinder part 41; and a sensor part 44 attached to a longitudinal end of the cylinder part 41. The sensor part 44 detects a protruding length of a protruding part 45 of the flexible material part 42 protruding from the longitudinal end of the cylinder part 41 in conjunction with elastic deformation of the cylinder part 41.SELECTED DRAWING: Figure 3

Description

The present invention relates to a touch sensor that detects a foreign object being pinched by a moving body such as an automatic door.

2. Description of the Related Art Some vehicles such as automobiles and railways and buildings are equipped with an electric opening/closing device that automatically opens and closes a door using a motor or the like. In such an electric opening/closing device, when the door is closed, for example, an object may be caught between the door frame and the door body in the case of a single door, or between the door body in the case of a double door. . In such a case, it is necessary for the electric opening/closing device to stop closing the door, open the door, and remove the caught object. Therefore, there is a need for a sensor that quickly detects contact between an object and a door or door frame.

For example, Patent Literature 1 discloses the following sensor. As shown in FIG. 4, the pressure-sensitive sensor 500 includes an elongated skin 510 made of an insulating elastic material such as rubber or soft synthetic resin. A cross hole 560 having a substantially cross-shaped cross section is formed inside the outer skin portion 510 along the longitudinal direction of the outer skin portion 510 . The cross hole 560 is gradually displaced around the center of the skin portion 510 along the longitudinal direction of the skin portion 510 .

Inside the skin part 510, there are four electrode wires 520 as electrodes that are formed in a flexible long cord shape by twisting conductive thin wires such as copper wires and coated with conductive rubber. 530, 540, 550 are provided. These electrode wires 520 to 550 are spirally arranged along the cross hole 560 while being separated from each other via the cross hole 560 in the vicinity of the center of the cross hole 560, and integrally connected to the inner peripheral portion of the cross hole 560. It is stuck.

Therefore, the electrode wires 520 to 550 are bent by contact with an object and the skin portion 510 is elastically deformed. contacts the electrode wire 540 or the electrode wire 550 and conducts. In addition, when the object is separated and the skin part 510 is restored, the electrode wires 520 to 550 are also restored and the conduction is interrupted.

Further, for example, Patent Document 2 discloses a protector 200 with the following sensor. As shown in FIG. 5, the protector 200 includes a mounting base 300 having a substantially U-shaped cross section and formed integrally therewith, which is attached to the front end surface of a sliding door of an automobile and is composed of an inner side wall 310, an outer side wall 320, and a connecting wall 330. In the hollow part 400, when a foreign object such as a part of the human body (fingers or limbs) is caught between the sliding door and the body side opening, an electric current is detected and responds to the pinching. A sensor (pressure sensor) 600 that outputs a signal is attached.

The sensor 600 has two core wires (electrode wires) 410 and 420 extending in the vertical direction (longitudinal direction) of the vehicle connected to conductive rubber-like elastic bodies (conductive portions) 450 and 460 with a space 440 interposed therebetween. It is fixed in the hollow part 400 so as to be embedded, and when a foreign object is caught between the sliding door and the body side opening when the sliding door is closed, the hollow part 400 is partially pressed and crushed, and the rubber The two core wires 410 and 420 are short-circuited when the elastic bodies 450 and 460 come into contact with each other, and the presence of a foreign object is detected.

JP-A-2002-235480 JP 2016-097810 A

By the way, in Patent Document 1, even if the skin portion 510 starts to elastically deform, the cross hole 560 is crushed and the electrode wire 520 or the electrode wire 530 contacts the electrode wire 540 or the electrode wire 550 and becomes conductive. , it is not possible to detect object entrapment. Also, in Patent Document 2, until the two core wires 410 and 420 are short-circuited by the hollow portion 400 being deformed and the rubber-like elastic bodies 450 and 460 coming into contact with each other due to an object being pinched, the object is Entrapment cannot be detected. Therefore, both of the above-mentioned patent documents have a time lag between contact with an object (that is, the object being pinched) and detection of the object.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a touch sensor capable of reliably and quickly detecting contact with an object.

In order to solve the above-mentioned problems, the present invention of claim 1 provides a cylindrical portion that is elastically deformed by an external force due to contact with an object, and a flexible material that is more flexible than the material that constitutes the cylindrical portion and is filled in the cylindrical portion. and a sensor portion attached to the longitudinal end portion of the cylindrical portion, the sensor portion being the amount of protrusion of the flexible material portion that protrudes from the longitudinal end portion of the cylindrical portion as the cylindrical portion is elastically deformed. It is a touch sensor that detects

According to the first aspect of the present invention, the cylindrical portion is elastically deformed by an external force due to contact with an object, and the flexible material portion is filled in the cylindrical portion and has higher flexibility than the material forming the cylindrical portion. When the tubular portion is elastically deformed by an external force due to contact with an object, the volume inside the tubular portion decreases. Since the cylindrical portion is filled with a flexible material portion that is more flexible than the material that constitutes the cylindrical portion, the cylindrical portion bends due to contact with an object, and the volume inside the cylindrical portion decreases. The protruding portion appears by being pushed out from the longitudinal end portion of the tubular portion. Since a sensor for detecting the amount of protrusion of the flexible material is provided at the longitudinal end of the tube, the external force applied to the tube is instantaneously detected as the amount of protrusion of the flexible material, can be output. Therefore, it is possible to reliably and quickly detect the presence or absence of contact with an object, the magnitude of the external force due to the contact, and the like, based on the amount of protrusion of the protrusion and the amount of change in the amount of protrusion.

The detection means of the sensor may detect the amount of protrusion of the protrusion, which is the pressure received by the sensor, or may detect the length of the protrusion of the flexible material protruding from the end of the cylinder. .

The touch sensor includes a cylindrical portion that is elastically deformed by an external force due to contact with an object, a flexible material portion that is more flexible than the material that constitutes the cylindrical portion and is filled in the cylindrical portion, and a longitudinal end portion of the cylindrical portion. An attached sensor portion is provided, and the sensor portion detects the amount of protrusion of the soft material portion protruding from the longitudinal end of the tubular portion as the tubular portion is elastically deformed. It can be detected and output as the amount of protrusion of the protrusion. Therefore, it is possible to reliably and quickly detect the presence or absence of contact with an object, the magnitude of the external force due to the contact, and the like, based on the amount of protrusion of the protrusion and the amount of change in the amount of protrusion.

1 is a perspective view showing an example in which a touch sensor of the present invention is applied to an entrapment detection device for a sliding door of an automobile; FIG. FIG. 2 is a cross-sectional view taken along the line XX of FIG. 1; 1A and 1B are longitudinal cross-sectional views for explaining the operation of the touch sensor of the present invention, in which (a) shows a state in which an object is not sandwiched, and (b) shows a state in which an object is sandwiched. It is a cross-sectional view of a conventional sensor (Patent Document 1). It is a cross-sectional view of a conventional sensor (Patent Document 2).

FIG. 1 is a perspective view showing an example in which a touch sensor 40 of the present invention is applied to an entrapment detection device for a sliding door 10 of an automobile. This entrapment detection device is a protector 20 having a touch sensor 40 formed at the tip portion attached to the opening end portion of the door panel 11, and having a long shape. This touch sensor 40 is used to detect the pinching of an object such as a part of the human body (fingers or limbs) between the door frame 12 and the door panel 11 . Note that the dimensions, materials, and characteristic values shown below are examples, and are not limited to the items described.

As shown in FIGS. 2 and 3(a), the protector 20 with the touch sensor 40 is mounted directly on a flange (not shown) formed on the sliding door 10 shown in FIG. A mounting base 30 having a substantially U-shaped cross section and a connecting wall 33, and a door frame 12 formed integrally with the mounting base 30 and facing the front end surface of the sliding door 10 when the sliding door 10 is closed. A tube-shaped cylindrical portion 41 that elastically contacts a foreign object such as a finger when the foreign object is present therebetween; It is composed of a sensor portion 44 attached to an upper end portion of a tubular portion 41 extending in the vertical direction (longitudinal direction) of the vehicle. A lower end portion of the cylindrical portion 41 extending in the vertical direction (longitudinal direction) of the vehicle is sealed with a sealing portion 43 made of the same material as the cylindrical portion 41 . The sealing portion 43 is formed so as not to bend even when an object 50 (FIG. 3(b)) is sandwiched therebetween. Note that the sealing portion 43 may be made of a material harder than the tubular portion 41 .

A plurality of retaining lips 34, 34 are formed inside the mounting base 30, and a core member (insert) 35 having a substantially U-shaped cross section is embedded in the mounting base 30 to increase rigidity. Further, a design lip 36 is formed on the vehicle outer side wall 32 of the mounting base 30 .

The operation of the touch sensor 40 of the present invention will now be described with reference to FIGS. 3(a) and 3(b). As shown in FIG. 3( a ), a tubular tubular portion 41 is filled with a flexible material portion 42 having higher flexibility than the material forming the tubular portion 41 . A lower tip portion of the cylindrical portion 41 is sealed with a sealing portion 43, and an upper tip portion thereof is open. A sensor portion 44 is attached to the upper end portion of the tubular portion 41 .

When the object 50 comes into contact with the tubular portion 41 and pressure is applied to the tubular portion 41, bending occurs in the tubular portion 41. As shown in FIG. Therefore, the soft material portion 42 filled inside the cylindrical portion 41 is pushed upward from the upper tip portion of the cylindrical portion 41, and the projecting portion 45 appears. Further, when contact with the object 50 is eliminated and the cylindrical portion 41 is restored, the soft material portion 42 is also restored and the projecting portion 45 disappears.

Since the sensor portion 44 is attached to the upper end portion of the cylindrical portion 41 , the sensor portion 44 detects the pressure change by the projecting portion 45 or detects the projecting length of the projecting portion 45 in the longitudinal direction. It should be noted that the detection of the pressure by the projecting portion 45 may be performed by detecting a direct pressing force by the projecting portion 45 , an air layer is formed between the sensor portion 44 and the soft material portion 42 , and the air pressure is detected by the projecting portion 45 . Indirect pressure due to layer capacitance changes may also be detected. Since there is a proportional relationship between the amount of bending of the cylindrical portion 41 and the length of the projecting portion 45 in the longitudinal direction, the contact of the object 50 can be reliably and quickly detected.

For example, if the influence on the human body (especially the head, fingers and limbs) is taken into account and reference values are set for the pressure detected by the sensor unit 44 and the length of the protrusion 45 in the longitudinal direction, the sliding door 10 When the object 50 comes into contact with the cylindrical portion 41 during the closing of the door, and the cylindrical portion 41 is flexed to a certain degree, it is determined that there is a pinch, and the operation of closing the sliding door 10 is stopped and the operation of opening the sliding door 10 is started. It can be carried out.

In this embodiment, the attachment base 30 (excluding the insert) of the protector 20 and the cylindrical portion 41 of the touch sensor 40 are made of dynamically crosslinked thermoplastic elastomer (TPV). The Young's modulus is 3 MPa, the inner diameter of the cylindrical portion 41 is 20 mm, and the wall thickness is 2 mm.

On the other hand, the soft material portion 42 filled in the tubular portion 41 is made of a hot-melt styrene-based elastomer. The Young's modulus is 0.0023 MPa, the Poisson's ratio is 0.29, and the coefficient of friction with the tubular portion 41 is 2.

In an experiment in which the cylindrical portion 41 was bent by the object 50, the projecting volume of the projecting portion 45 that protruded when the cylindrical portion 41 was pushed in by 1600 ^mm3 was 1200 ^mm3 , and the ratio of the projecting volume to the pushing volume was 75%. Ta. It was also confirmed that there is a proportional relationship between the indentation volume change amount and the protrusion volume change amount.

The sensor unit 44 is attached, and the pressure change in the sensor unit 44 has not been measured. , can be converted into an electrical signal and output.

Detection by the sensor portion 44 may be performed by contacting the sensing portion of the sensor portion 44 with the flexible material portion 42 and directly receiving pressure from the protruding portion 45 , or by detecting pressure between the sensor portion 44 and the tubular portion 41 . An air layer may be formed between the sensing portion of the sensor portion 44 and the soft material portion 42 by sealing by adhesion or the like, and the air layer may be indirectly compressed as a pressure when the projection portion 45 appears.

The implementation of the present invention is not limited to the above embodiments, and various modifications are possible without departing from the object of the present invention.

Materials for forming the protector 20 (excluding the insert) and the cylindrical portion 41 of the touch sensor 40 may be rubber, thermoplastic elastomer, soft synthetic resin, or the like. In the case of rubber, EPDM (ethylene propylene diene rubber) is preferable, and in addition to TPV, olefinic thermoplastic elastomer (TPO) is preferable as a thermoplastic elastomer from the viewpoints of weather resistance, recycling, cost, and the like.

For example, in the above-described embodiment, the mounting base 30 (excluding the insert) of the protector 20 and the cylindrical portion 41 of the touch sensor 40 are made of TPV having the same characteristics, but the mounting base 30 and the cylindrical portion 41 have different characteristic values. A TPV with a TPV may be used, or a different material may be used.

For example, in the above-described embodiment, the upper end portion of the cylindrical portion 41 is open to expose the soft material portion 42, but it may be sealed with a thin film that does not interfere with detection by the sensor portion 44.

For example, the detection means of the sensor section 44 may detect by a method of measuring the longitudinal length of the protruding portion 45 of the soft material portion 42 protruding from the cylindrical portion 41, in addition to using the pressure-sensitive element described above. .

Although the embodiment of the present invention has been described using an example in which it is installed in the sliding door 10 of an automobile, it is possible to install it in various devices without being limited to this. For example, in the case of automobiles, it can be applied to power back doors, electric sunroofs, electric headrests, electric seats, electric operation steps, power windows, electric ottomans, and the like. Moreover, it can be installed not only in automobiles but also in automatic doors of buildings (including revolving doors), doors of elevators, doors of railways, and the like.

REFERENCE SIGNS LIST 10 sliding door 11 door panel 12 door frame 20 protector 40 touch sensor 41 cylindrical portion 42 soft material portion 43 sealing portion 44 sensor portion 45 projecting portion 50 object

Claims (1)

a cylindrical portion that is elastically deformed by an external force caused by contact with an object;
a flexible material portion having higher flexibility than the material forming the tubular portion and filled in the tubular portion;
A sensor unit attached to an end in the longitudinal direction of the tubular portion,
The sensor section is a touch sensor that detects a protrusion amount of a protruding section of the soft material section that protrudes from a longitudinal end of the tubular section as the tubular section is elastically deformed.

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