JP5860801B2 - Pressure detection cable - Google Patents

Description

  The present invention relates to a pressure detection cable for detecting that pressure has been applied.

  In general, an automatic opening / closing device provided in a vehicle, a building, or the like has a pressure detection cable, and the pressure detection cable is described in Patent Document 1, for example. The pressure detection cable described in Patent Document 1 has two electrodes and a tubular body (hollow insulator) in which the two electrodes are accommodated. A part of the outer peripheral surface of the two electrodes is embedded in the inner peripheral surface of the tubular body, and the two electrodes are fixed spirally along the longitudinal direction of the tubular body. The two electrodes are held in a state where they are not in electrical contact by being fixed to the inner peripheral surface of the tubular body. Furthermore, the tubular body is made of a recoverable rubber or a recoverable plastic, and the tubular body has a characteristic of being deformed when a pressure is applied and restoring the original shape when the pressure is lowered.

  A power source and an ammeter are connected to one end of the two electrodes, and a current adjusting resistor is connected to the other end of the two electrodes to form an electric circuit. Yes. Furthermore, the electric circuit is energized, and when the object comes into contact with the tubular body and the tubular body is deformed, the two electrodes come into contact with each other and a short-circuit current flows, and pressure is applied based on this increase in current. Can be detected.

Japanese Patent No. 3707996

  By the way, it is as follows when the process at the time of manufacturing the cable for pressure detection described in patent document 1 is estimated. First, a long member (core) having two spiral grooves formed on the outer peripheral surface is prepared, and an intermediate body is formed by spirally winding two electrodes around the outer peripheral surface of the long member. To do. Next, the intermediate body is placed in the cavity of the mold, and an insulating material is injected into the cavity and solidified to form a tubular body. Furthermore, a manufacturing method is conceivable in which a mold is opened, a molded product is taken out from the mold, and further pulled out from the molded product while rotating the core to obtain a pressure detection cable. However, in this manufacturing method, there is a problem that the manufacturing process is troublesome because a step of pulling out the core while rotating the core from the inside of the tubular body of the manufactured pressure detection cable is necessary.

  An object of the present invention is to provide a pressure detection cable that is easy to manufacture.

  The pressure detection cable according to the present invention is provided with a tubular body that is elastically deformed when pressure is applied, and is provided inside the tubular body, and the tubular body is deformed when pressure is applied to the tubular body. A pressure detecting cable having a plurality of electrodes that are electrically connected to each other, provided inside the tubular body, and holding the plurality of electrodes in a non-conductive state when the tubular body is not deformed; And a first separator having a plurality of protrusions provided on the outer peripheral surface at intervals in the circumferential direction, wherein the plurality of electrodes are arranged in a spiral shape so as to surround the first separator, In a plane cross section perpendicular to the longitudinal direction of the tubular body, the relationship between the outer diameter H of the circumscribed circle of the first separator, the outer diameter φ of each of the plurality of electrodes, and the thickness b of the protrusion is as follows: Formula 1

であることを特徴とする。

It is characterized by being.

  In the pressure detection cable of the present invention, the relationship between the outer diameter H and the outer diameter φ is H ≦ (2/3) φ in the plane cross section.

  In the pressure detection cable of the present invention, the protrusions of the first separator are formed in a spiral shape, and the plurality of electrodes are individually disposed between the plurality of protrusions. And

  In the pressure detection cable of the present invention, a second separator is disposed inside the tubular body, and the second separator has the same spiral direction as the first separator on the outer periphery of the first separator and the plurality of electrodes. It is provided in a spiral shape, and is arranged in contact with two adjacent electrodes among the tubular body and the plurality of electrodes.

  The pressure detection cable according to the present invention is characterized in that the plurality of electrodes are welded and fixed to the outer peripheral surface of the first separator.

  According to the present invention (Claim 1), the plurality of electrodes are held in a non-contact state by the first separator. Therefore, there is no element taken out from the inside of the tubular body after the manufacture of the pressure detection cable, the increase in the manufacturing process of the pressure detection cable can be suppressed, and the manufacture is easy. Further, when pressure is applied to the pressure detection cable, the contact pressure between the electrodes can be increased as soon as possible. Therefore, the pressure detection cable improves the pressure detection sensitivity.

According to the present invention (Claim 1 ), the pressure detection sensitivity can be further improved.

According to the present invention (Claim 2 ), since the plurality of electrodes are individually disposed between the plurality of protrusions, when the applied pressure is less than a predetermined value, the electrodes are reliably in contact with each other. Can be prevented.

According to the present invention (Claim 3 ), it is possible to reliably prevent the electrodes from contacting each other in a state where no pressure is applied.

It is the perspective view which fractured | ruptured some pressure detection cables of this invention. It is typical sectional drawing in the diameter direction of the cable for pressure detection of this invention. It is a conceptual diagram which shows the cable for a pressure detection of this invention, and an electric circuit. It is a typical sectional view in the state where pressure was added to the cable for pressure detection of the present invention. It is a typical sectional view in the state where pressure was added to the cable for pressure detection of the present invention. It is typical sectional drawing which shows the structure of the cable for pressure detection of this invention. It is typical sectional drawing which shows the other specific example of the cable for pressure detection of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. A pressure detection cable 10 shown in FIGS. 1 and 2 is provided with a hollow tubular body 11, four electrodes 12, 13, 14, 15 provided inside the tubular body 11, and inside the tubular body 11. The first separator 16 and the second separator 17 are provided. The tubular body 11 includes a cylindrical conductive layer 11a and a cylindrical insulating layer 11b formed so as to cover the outer peripheral surface of the conductive layer 11a. The conductive layer 11a is formed of an elastic material having at least an inner portion having conductivity. The conductive layer 11 a has a circular outer peripheral shape in a plane cross section along the diameter direction of the tubular body 11. Here, the plane cross section along the diameter direction of the tubular body 11 means a plane cross section perpendicular to the longitudinal direction of the tubular body 11. In addition, the circular cross-sectional shape means a shape in a state where no pressure is applied to the tubular body 11. The conductive layer 11a is flexible, that is, has a characteristic of being deformed by an applied pressure. The conductive layer 11a is made of, for example, conductive rubber, conductive plastic, or the like.

  On the other hand, the insulating layer 11b of the tubular body 11 is made of a flexible material. Specifically, the insulating layer 11b is elastically deformed when a pressure in the diametrical direction is applied, and has a restoring property that returns to the original shape when the applied pressure is reduced. The insulating layer 11b is an insulator that does not pass current. As a material constituting the insulating layer 11b having such characteristics, a recoverable rubber, a recoverable plastic, or the like can be used. The conductive layer 11a and the insulating layer 11b may be constituted by separate members and bonded to each other with an adhesive to form the tubular body 11. Alternatively, the inner portion of the tubular body 11 that is physically made of the same material may be used as the conductive layer 11a. The outer portion of the tubular body 11 may be the insulating layer 11b.

  The four electrodes 12, 13, 14, 15 provided inside the tubular body 11 are both conductive and flexible, and the four electrodes 12, 13, 14, 15 are made of a metal conductor 18. And a covering layer 19 that covers the outer peripheral side of the conducting wire 18. The conductive metal material constituting the conductive wire 18 includes copper, copper alloy, and the like. The conducting wire 18 may be a single piece or a plurality of conducting wires 18 may be combined. The covering layer 19 is made of a conductive material, for example, conductive rubber, conductive plastic or the like, and has a higher resistance value than the conductive wire 18. The four electrodes 12, 13, 14, and 15 each have a circular cross section in the diameter direction (perfect circle), and the four electrodes 12, 13, 14, and 15 have the same outer diameter. Here, the circular cross-sectional shape means a shape of the electrodes 12, 13, 14, 15 in a state where no pressure is applied.

  The first separator 16 provided in the tubular body 11 prevents at least two of the electrodes 12, 13, 14, and 15 from coming into contact with each other when no pressure is applied to the pressure detection cable 10. Is an element. The first separator 16 is provided at the center in the diameter direction of the tubular body 11, and has a long shape arranged along the longitudinal direction of the tubular body 11. The first separator 16 is elastically deformed when a pressure is applied, and has a resilience that returns to its original shape when the pressure decreases. The first separator 16 is made of an insulating material. The material constituting the first separator 16 includes a recoverable rubber, a recoverable plastic, and the like.

  Further, four protrusions (ribs) 16 a extending in the diameter direction are provided on the outer peripheral surface of the first separator 16. The four protrusions 16 a are arranged at 90 ° intervals along the circumferential direction of the first separator 16. That is, the first separator 16 has a cross shape in the plane cross section in the diametrical direction of the tubular body 11. The four protrusions 16 a are formed in a spiral shape along the longitudinal direction of the first separator 16. The four protrusions 16a have the same helical pitch in the longitudinal direction of the first separator 16. The pitch means the length in the longitudinal direction of the first separator 16 when the projecting portion 16 a makes one round in the circumferential direction of the first separator 16.

  Furthermore, on the outer peripheral surface of the first separator 16, four recesses 16b are formed along the longitudinal direction between the protrusions 16a. That is, the four concave portions 16b are formed in a spiral shape on the outer peripheral surface of the first separator 16, and the four concave portions 16b have the same twist direction. The four recesses 16b have the same spiral pitch in the longitudinal direction of the first separator 16.

  Four electrodes 12, 13, 14, and 15 are individually arranged between the protrusions 16 a of the first separator 16, that is, in the recess 16 b, and in the spiral direction of the protrusion 16 a and the recess 16 b. Along the outer periphery of the first separator 16, four electrodes 12, 13, 14, and 15 are spirally wound. And since the protrusion part 16a is located between adjacent electrodes, adjacent electrodes are mutually non-contact in the state in which the pressure is not applied. Of course, electrodes that are not adjacent to each other are also non-contact.

  In a state in which the electrodes 12, 13, 14, 15 are spirally wound around the outer peripheral surface of the first separator 16, the four electrodes 12, 13, 14, The outer peripheral shape of 15 is an ellipse (oval). That is, the cross section of the four electrodes 12, 13, 14, 15 has a major axis and a minor axis. The drawings referred to in this embodiment all represent a planar cross section in the diameter direction of the tubular body 11, but for convenience, the outer peripheral shape of the four electrodes 12, 13, 14, and 15 is not an ellipse but a perfect circle. It is shown. In the circumferential direction of the first separator 16, the electrodes 13 and 15 are disposed on both sides of the electrode 12, and the electrode 13 is opposed to the electrode 12 between the electrode 13 and the first separator 16. An electrode 14 is disposed on the surface.

  Inside the tubular body 11, the second separator 17 formed of a linear insulator is further provided in the state where the electrodes 12, 13, 14, 15 are wound around the first separator 16. 16 and electrodes 12, 13, 14, and 15 are wound around the outer periphery in a spiral shape. Further, the second separator 17 is disposed to face the protruding portion 16 a of the first separator 16. The second separator 17 is disposed in contact with the conductive layer 11a of the tubular body 11 and two adjacent electrodes. In each figure, for convenience, the second separator 17 is a conductive material that is the inner peripheral surface of the tubular body 11. It is shown in contact with the layer 11a and the electrodes 14,15. The twist direction of the second separator 17 is the same as the twist direction of the four electrodes 12, 13, 14, 15 and the spiral direction of the protrusion 16 a of the first separator 16.

  The 2nd separator 17 has the tensile strength fiber 17a and the cylindrical coating layer 17b which covered the outer side of the tensile strength fiber 17a. The covering layer 17b is made of recoverable rubber or recoverable plastic. As for the 2nd separator 17, the outer peripheral shape in the plane cross section in the diameter direction of the tubular body 11 is circular.

  Here, the circular outer peripheral shape means a shape in a state where no pressure is applied to the second separator 17. Further, the spiral pitch in the longitudinal direction of the second separator 17 is the same as the spiral pitch of the protrusions 16a. Further, the outer peripheral shape of the second separator 17 is an ellipse (oval) in the plane cross section in the diametrical direction of the tubular body 11, but in the drawing referred to in the present embodiment, it is shown as a circle for convenience.

  As described above, the twist direction of the second separator 17 is the same as the twist direction of the electrodes 12, 13, 14, and 15 and the spiral direction of the first separator 16, and the spiral pitch of the second separator 17 is the first. The pitch is set to be the same as the helical pitch of the protrusions 16 a of the separator 16. Thereby, the arrangement of the first separator 16, the electrodes 12, 13, 14, 15 and the second separator 17 is always equal in the longitudinal direction of the pressure detection cable 10. As a result, even when pressure is applied to the pressure detection cable 10 and deformed, the pressing force that electrically connects the electrodes 12, 13, 14, and 15 can be kept constant in the longitudinal direction of the pressure detection cable 10. Further, it is possible to prevent the pressing force for electrically connecting the electrodes 12, 13, 14, and 15 from varying depending on the place where the pressure is applied to the pressure detection cable 10.

  Further, since the second separator 17 is disposed at a position facing the protruding portion 16 a of the first separator 16, the outer peripheral surface of the second separator 17 is the conductive layer 11 a that is the inner peripheral surface of the tubular body 11. The electrodes 12, 13, 14, and 15 are in contact with the three outer peripheral surfaces of two adjacent electrodes. Accordingly, in the cross-sectional view of the pressure detection cable 10, the second separator 17 is held in contact with the above-mentioned three locations, and therefore the location where the tubular body 11 and the second separator 17 are in contact is from the outside of the tubular body 11. When the pressed pressure is applied to the pressure detection cable 10, the pressure applied to the pressure detection cable 10 is directly applied to the first separator 16 and the electrode without the second separator 17 changing the relative position between the tubular body 11 and the electrode. 12, 13, 14, 15. Therefore, it is possible to prevent the pressure applied to the pressure detection cable 10 from escaping due to the deformation of the structure constituting the pressure detection cable 10 and increasing the detection pressure.

  The twist direction of the second separator 17 is the same as the twist direction of the electrodes 12, 13, 14, 15 and the spiral direction of the first separator 16, and the spiral pitch of the second separator 17 is the same as that of the first separator 16. Since the pitch of the protrusions 16a is the same as that of the spiral, the second separator 17 is disposed radially inward of the circumscribed circle of the four electrodes 12, 13, 14, and 15, so that the outer diameter of the pressure detection cable 10 is increased. Can be made thinner.

  Next, an example of an electric circuit to which the pressure detection cable 10 is connected will be described with reference to FIG. In the electric circuit 20, the four electrodes 12, 13, 14, 15 are connected in series, and in detail, are connected as follows. One end of the electrode 12 is electrically connected to the power source 21 and the resistance measuring instrument 22, and the other end of the electrode 12 is electrically connected to one end of the electrode 13. The other end of the electrode 13 is electrically connected to one end of the electrode 14 via a detection resistor 23.

  The other end of the electrode 14 is electrically connected to one end of the electrode 15, and the other end of the electrode 15 is grounded to the ground 24 and electrically connected to the resistance measuring instrument 22. Therefore, the four electrodes 12, 13, 14, 15 are connected to the power source 21, the resistance measuring device 22, the detection resistor 23 and the ground 24 on one end side of the pressure detection cable 10. On the end side, the electrodes 12 and 13 and the electrodes 14 and 15 are electrically connected to each other. Thus, the electrodes are connected to each other only at the other end of the pressure detection cable 10, and the resistance measuring device 22 or the detection resistor 23 is connected to the electrodes 12, 13, 14, 15 at one end of the pressure detection cable 10. Since it can be performed only on the side, the electrodes 12, 13, 14, 15 in the pressure detection cable 10 can be easily connected. The resistance measuring device 22 is an element that detects the resistance of current in the electric circuit 20. The resistance measuring device 22 is connected to an electronic control device (controller) 25. At least two of the electrodes 12, 13, 14, and 15 are in direct contact with the electronic control device 25 by the pressure applied to the pressure detection cable 10 based on the resistance value detected by the resistance measuring device 22, or It is determined that conduction is made through the tubular body 11. That is, the electronic control unit 25 has a function of determining whether or not the actual pressure (actual applied pressure) applied to the pressure detection cable 10 is equal to or higher than a predetermined value (reference applied pressure).

  Next, the operation of the pressure detection cable 10 will be described. A protrusion 16a of the first separator 16 is disposed between the four electrodes. For this reason, unless an object is in contact with the pressure detection cable 10, adjacent electrodes do not contact (short-circuit). A second separator 17 is disposed between the four electrodes 12, 13, 14, and 15 alone and the conductive layer 11a. For this reason, a gap is formed between each of the electrodes 12, 13, 14, and 15 and the conductive layer 11a, which is in a non-contact state. In this state, since the current flowing from the power source 21 to the electric circuit 20 sequentially passes through the electrode 12, the electrode 13, the detection resistor 23, the electrode 14, and the electrode 15, the actual resistance value detected by the resistance measuring instrument 22 (actual Resistance value) is the resistance value of the detection resistor 23. Here, the electronic control unit 25 stores in advance a predetermined value (reference resistance value) lower than the resistance value of the detection resistor 23 as a threshold value for determining whether or not pressure is applied to the pressure detection cable 10. Yes. When the actual resistance value detected by the resistance measuring device 22 is equal to or greater than a predetermined reference value, the electronic control unit 25 determines that no pressure is applied to the pressure detection cable 10.

  On the other hand, when an object contacts the pressure detection cable 10 and the center A of the first separator 16 is positioned on the extension line S of the pressure F applied to the tubular body 11 as shown in FIG. Will be explained. When pressure is applied to the tubular body 11 and elastically deforms in the diameter direction, at least two electrodes come into contact with the conductive layer 11a. FIG. 4 shows an example in which the electrodes 13 and 14 are in contact with the conductive layer 11a for convenience. As a result, the electrode 13 and the electrode 14 are short-circuited (short-circuited) in the detection resistor 23, and the electric circuit 20 has two conduction paths through the detection resistor 23 and the short-circuited conduction path not through the detection resistor 23. A parallel circuit is formed. The resistance value of the short-circuited conduction path not passing through the detection resistor 23 becomes a resistance value that the covering layer 19 of the electrode 13 and the electrode 14 has, that is, a resistance value higher than that of the conducting wire 18.

  For this reason, the actual resistance value detected by the resistance measuring device 22 becomes a combined resistance of the parallel circuit of the two conduction paths, and becomes smaller than the state where the electrode does not contact the conductive layer 11a. Resistance value). Therefore, when the actual resistance value detected by the resistance measuring device 22 is less than the reference predetermined value, the electronic control unit 25 determines that the pressure is applied to the pressure detection cable 10. When the object is separated from the pressure detection cable 10, the tubular body 11 is restored to its original shape, and all the electrodes 12, 13, 14, 15 are separated from the conductive layer 11a.

  Furthermore, a case where the center A of the first separator 16 is not located on the extension line S of the pressure F applied to the pressure detection cable 10 as shown in FIG. 5 will be described. Specifically, when the tubular body 11 is elastically deformed by a small external force and comes into contact with the electrode 12, the electrode 12 is elastically deformed while pressing the first separator 16. Then, the first separator 16 is elastically deformed so that the protruding portion 16a falls, and the electrode 12 is deformed and moved so as to get over the protruding portion 16a of the first separator 16, and adjacent electrodes come into contact with each other. FIG. 5 shows an example in which the electrode 12 and the electrode 13 are in contact with each other.

  The pressure detection cable 10 of the present embodiment is configured as follows to achieve the above operation. Specifically, as shown in FIG.

の構成を有する。ここで、φは電極１２，１３，１４，１５における単独の直径（外径)であり、Ｈは第１セパレータ１６における外接円Ｂの直径（外径)である。また、φおよびＨそれぞれは、電極が管状体１１の内部に配置されていない状態、つまり、略直線状に延ばされた状態における電極の直径である。また、ｂは、突出部１６ａの厚みであり、その値がとりうる範囲は、数式３

It has the composition of. Here, φ is the single diameter (outer diameter) of the electrodes 12, 13, 14, and 15, and H is the diameter (outer diameter) of the circumscribed circle B in the first separator 16. Further, φ and H are the diameters of the electrodes in a state where the electrodes are not arranged inside the tubular body 11, that is, in a state where the electrodes are extended substantially linearly. Further, b is the thickness of the protruding portion 16a, and the range that the value can take is expressed by Equation 3.

の構成を有する。

It has the composition of.

In particular, the pressure detection cable 10 of the present embodiment is more preferably,
H ≦ (2/3) φ Expression (1)
It has the composition of.

Furthermore, the range that φ and b can take in the pressure detection cable 10 of the present embodiment is more preferably φ ≧ 0.4 (mm).
b ≧ 0.15 (mm)
It is.

In the above Equation 3 and Equation (1),
H ≦ (2φ + b)
Or H ≦ (2/3) φ
Represents the upper limit of the diameter H of the circumscribed circle B of the first separator 16,

の事項、
φ／２≦Ｈ
の事項は、共に第１セパレータ１６の外接円Ｂの直径Ｈの下限値を表している。

Matters,
φ / 2 ≦ H
Both of these items represent the lower limit value of the diameter H of the circumscribed circle B of the first separator 16.

  The upper limit value of the diameter H of the circumscribed circle B of the first separator 16 is a value when the protruding portion 16a of the first separator 16 exists up to a position in contact with the line connecting the outer peripheries of the adjacent electrodes. The value is set to make the actual contact pressure between the electrodes as low as possible when the pressure is applied to the detection cable 10 and is set to make the actual contact pressure between the electrodes as low as possible. That is, no matter which direction the actual contact pressure is applied to the pressure detection cable 10, the current flow resistance at the contact portion between the electrodes decreases, and the change width of the actual resistance measured by the resistance measuring device 22. Becomes larger. As a result, the electronic control unit 25 can easily determine that the pressure is applied to the pressure detection cable 10, and the sensitivity of pressure detection by the pressure detection cable 10 is improved. In other words, the pressure (detection load) at which it is determined that pressure is applied to the pressure detection cable 10 can be made as small as possible.

  Further, when pressure is applied to the pressure detection cable 10, the deformation amount of the tubular body 11 from when the tubular body 11 starts to be deformed until the actual contact pressure between the electrodes becomes equal to or higher than the reference contact pressure (ON). (Stroke) can be made as small as possible. In addition, in the longitudinal direction of the pressure detection cable 10, it is possible to reduce a portion (cross section) where the actual contact pressure between the electrodes is less than the reference contact pressure.

  On the other hand, the lower limit value of the circumscribed circle B of the first separator 16 is a square having a diagonal line between the opposing circles in a line connecting the centers of the opposing electrodes in a state where the four electrodes are in contact with each other. This is set to prevent the actual contact pressure between the electrodes from exceeding the reference contact pressure when no pressure is applied when the pressure detection cable 10 is bent and attached. It is the value. That is, the lower limit value is a value determined based on the shape of the object to which the pressure detection cable 10 is attached, the radius of curvature (R) of the curved portion of the object, and the like.

  Therefore, in the pressure detection cable 10, when the pressure is applied, the timing at which the actual contact pressure becomes equal to or higher than the reference contact pressure is earlier in the configuration of Formula 2 than in the configuration of Formula 1.

  Also, if the pitch between the electrodes 12, 13, 14, 15 and the pitch between the protrusions 16a are made as small as possible, even if the pressure detection cable 10 is bent and attached and the electrodes come into contact with each other, the actual contact pressure is The reference contact pressure is not exceeded. Therefore, the pressure detection cable 10 can be easily bent according to the shape of the object, and the followability is improved.

  Next, another configuration example of the pressure detection cable 10 will be described with reference to FIG. In FIG. 7, the first separator 26 has a circular (perfect circle) outer peripheral shape in a plane cross section in the diametrical direction. The four electrodes 12, 13, 14, 15 are spirally attached to the outer peripheral surface of the first separator 26. The four electrodes 12, 13, 14, 15 are twisted in the same direction with respect to the first separator 26, and the four electrodes 12, 13, 14, 15 are welded to the outer peripheral surface of the first separator 26. It is fixed.

  In the pressure detection cable 10 shown in FIG. 7, since the planar cross-sectional shape of the first separator 26 is circular, the diameter of the first separator 26 matches the diameter of the circumscribed circle of the first separator 26. Furthermore, in the pressure detection cable 10 of FIG. 7, the relationship between the diameter H of the circumscribed circle (not shown) of the first separator 26 and the diameter φ of each of the four electrodes 12, 13, 14, 15 is It has the structure of Formula 1, preferably (Formula 1).

  In FIG. 7, the circumferential gap between adjacent electrodes on a virtual circle passing through the centers of the four electrodes 12, 13, 14, 15 can ensure the sensitivity of the pressure detection cable 10. In addition, the value is determined such that the electrodes do not contact each other when the actual pressure is low. The other configuration of the pressure detection cable 10 shown in FIG. 7 is the same as the configuration of the pressure detection cable 10 shown in FIGS. 1 and 2.

  In the embodiment of FIG. 7, when no pressure is applied to the pressure detection cable 10, the electronic control unit 25 determines that no pressure is applied to the pressure detection cable 10 based on the same principle as described above. To do. In addition, when pressure is applied to the pressure detection cable 10 and the electrode and the first separator 26 are elastically deformed, and at least two or more electrodes come into contact with the conductive layer, the electronic control device 25 operates according to the same principle as described above. Then, it is determined that pressure is applied to the pressure detection cable 10. Furthermore, when the direction of the pressure applied to the pressure detection cable 10 does not pass through the center of the first separator 26, the adjacent electrodes come into contact with each other, the actual resistance value decreases, and pressure is applied to the pressure detection cable 10. The determination is the same as described above.

  Furthermore, the pressure detection cable 10 shown in FIG. 7 has electrodes 12, 13, 14, and 15 welded and fixed to the first separator 26. At this time, the electrodes 12, 13, 14, and 15 are welded to the first separator 26 at positions where adjacent electrodes do not contact each other. Therefore, it can prevent reliably that adjacent electrodes contact in the state in which the pressure is not applied. Further, in the pressure detection cable 10 of FIG. 7, the same operational effects can be obtained with respect to the same components as the pressure detection cable 10 shown in FIGS. 1 and 2.

  Here, an example of the result of comparing the pressure detection cable of the present embodiment with the pressure detection cable of the comparative example will be described. In the pressure detection cable of the comparative example, the diameter of the circumscribed circle of the first separator exceeds the diameter of the electrode. In the pressure detection cable of this embodiment, the actual contact pressure started to increase from the actual applied pressure P1, and then the actual contact pressure became equal to or higher than the reference contact pressure at the actual applied pressure P2. On the other hand, in the pressure detection cable of the comparative example, the actual contact pressure did not start increasing at the actual applied pressure P1, and then the actual contact pressure became equal to or higher than the reference contact pressure at the actual applied pressure P3. Here, the actual pressure P2 is higher than the actual pressure P1, and the actual pressure P3 is higher than the actual pressure P2.

  In the pressure detection cable 10 of the present invention, a first separator 16 (26) is provided inside a tubular body 11, and a plurality of electrodes 12, 13, 14, and 15 are provided inside the tubular body 11. . The plurality of electrodes are held in a non-contact state by the first separator 16 (26). Therefore, there is no element taken out from the inside of the tubular body 11 after the manufacture of the pressure detection cable 10, it is possible to suppress an increase in the manufacturing process of the pressure detection cable 10, and the manufacture is easy.

  The pressure detection cable 10 of the present invention can be used, for example, in an automatic opening / closing device of a vehicle. Specifically, the pressure detection cable 10 is attached to an end of a vehicle door or an opening of a vehicle body. With this configuration, the electronic control unit 25 determines whether or not pressure is applied to the pressure detection cable 10 based on the actual resistance value detected by the pressure detection cable 10, that is, the human body or the baggage is for pressure detection. It can be determined whether or not the cable 10 is touched.

  The cable 10 for pressure detection according to the present invention includes a function of a touch sensor for detecting whether or not an object is in contact based on an actual applied pressure. The first separator 16 (26) of the present invention has a function of keeping the actual contact pressure between the electrodes below the reference contact pressure when no object is in contact with the pressure detection cable 10. Further, the first separator 16 (26) of the present invention has a function of determining the rise timing of the actual contact pressure between the electrodes when an object contacts the pressure detection cable 10 and pressure is applied. The tubular body 11 of the present invention has a function of accommodating the first separator 16 (26) and the plurality of electrodes 12, 13, 14, and 15, and a plurality of objects when an object contacts the pressure detection cable 10 and pressure is applied. It has a function of short-circuiting at least two of the electrodes 12, 13, 14, and 15 to make the electrodes conductive. Here, the correspondence between the configuration described in the present embodiment and the configuration of the present invention will be described. The first separators 16 and 26 correspond to the separator of the present invention.

  It goes without saying that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, the plurality of electrodes in the present invention includes less than 4 electrodes, or 5 or more electrodes. The separator of the present invention includes a separator having a circular shape in a plane cross section in the diametrical direction, a separator having a plurality of spiral recesses formed on the outer peripheral surface, and the like. The pressure detection cable of the present invention includes a configuration in which a plurality of spiral recesses are formed on the outer peripheral surface of the separator, and electrodes are disposed in the respective recesses. The recess in this embodiment is a structure for holding an electrode, and the recess includes a groove and a recess.

DESCRIPTION OF SYMBOLS 10 Pressure detection cable 11 Tubular body 11a Conductive layer 11b Insulating layer 12, 13, 14, 15 Electrode 16,26 1st separator 16a Protruding part 16b Recessed part 17 Second separator 17a Tensile fiber 17b, 19 Covering layer 18 Conductor 20 Electrical circuit 21 Power supply 22 Resistance measuring device 23 Detection resistor 24 Ground 25 Electronic control unit A, D Center B circumcircle E Virtual circle F Pressure H Diameter S Extension line φ Diameter

Claims (4)

A tubular body that is elastically deformed when pressure is applied, and a plurality of electrodes that are provided inside the tubular body and that are electrically connected to each other as the tubular body is deformed when pressure is applied to the tubular body. A pressure sensing cable having
Provided inside the tubular body, when the tubular body is not deformed, the plurality of electrodes are held in a non-conducting state, and a plurality of protrusions are provided on the outer peripheral surface at intervals in the circumferential direction. The plurality of electrodes are arranged in a spiral shape so as to surround the first separator,
Within a plane cross section perpendicular to the longitudinal direction of the tubular body, the relationship between the outer diameter H of the circumscribed circle of the first separator, the outer diameter φ of each of the plurality of electrodes, and the thickness b of the protrusion is , Formula 1

Der is,
Within the plane cross section, the relationship between the outer diameter H and the outer diameter φ is:
H ≦ (2/3) φ
Pressure detection cable, characterized in der Rukoto. In the pressure detection cable according to claim 1, wherein the projecting portion of the first separator is formed in a spiral shape, the plurality of electrodes, that are arranged singly between the adjacent plurality of protrusions This is a pressure sensing cable. 3. The pressure detection cable according to claim 1, wherein a second separator is disposed inside the tubular body, and the second separator is disposed on an outer periphery of the first separator and the plurality of electrodes. A pressure detection cable, wherein the pressure detection cable is provided in a spiral shape in the same direction as a spiral direction, and is arranged in contact with two adjacent electrodes of the tubular body and the plurality of electrodes . The pressure detection cable according to claim 1 , wherein the plurality of electrodes are welded and fixed to an outer peripheral surface of the first separator .

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