JP2009192454A - Polarization apparatus of cable-like pressure sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely polarize a flexible pressure sensing element, and improve the productivity and the reliability. <P>SOLUTION: A polarization apparatus includes: the flexible pressure sensing element 2 provided around a core electrode 1; a polarization electrode 3 disposed so as to contact the entire circumference of the flexible pressure sensing element 2, and composed of a plurality of balls and chains formed by a conductive material; a DC voltage generating means 7 connected to the core electrode 1 and the polarization electrode 3; a moving means 5 for moving the flexible pressure sensing element 2 in a path; a heating means 4 for heating the polarization electrode 3; a charge removing means 13 for removing a charge applied to the flexible pressure sensing element 2; a stress applying means 8 for applying a physical stress to the flexible pressure sensing element 2; and an output detecting means 9 for detecting an output generated from the flexible pressure sensing element 2 when the stress applying means 8 operates. Since the flexible pressure sensing element 2 can uniformly contact the balls and chains, the flexible pressure sensing element 2 can be uniformly polarized from the entire circumference. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a polarization device for a cable-shaped pressure sensor.

  Conventionally, as shown in FIG. 6, this type of cable-type pressure sensor has a structure in which a flexible pressure-sensitive body 102 is disposed around a core electrode 101 and an outer electrode 103 and an outer skin 104 are sequentially covered around the flexible pressure-sensitive body 102. Has been.

  The flexible pressure-sensitive body 102 is a composite in which a ceramic piezoelectric powder of lead titanate or lead zirconate titanate is added to synthetic rubber or synthetic resin, while the outer electrode 103 is a flexible pressure-sensitive body. The surface of 102 is coated with a conductive paint such as a silver-based rubber paint.

  When a pressure is applied to a part or the entire surface of the cable-shaped pressure sensor, the pressure sensor in that part is distorted. As a result, a voltage is induced between the core electrode 101 and the outer electrode 103, and this induced voltage is used. Thus, the pressure is detected (see, for example, Patent Document 1).

  As a polarization method, a high voltage is applied between the core electrode 101 and the outer electrode 103 to polarize the flexible pressure sensitive body 102 (see, for example, Non-Patent Document 1).

  Due to this polarization, the direction of spontaneous polarization of the ceramic particles is aligned with the direction of the electric field, so that piezoelectricity is imparted to the flexible pressure-sensitive body 102.

  As another method, as shown in FIG. 7, a flexible pressure-sensitive body 102 is disposed in the passage of the block-shaped conductor 105, and a voltage is applied between the block-shaped conductor 105 and the core electrode 101. The portion of the flexible pressure-sensitive body 102 disposed on the block-like conductor 105 is polarized (see, for example, Patent Document 2).

By this polarization, the direction of spontaneous polarization of the ceramic particles is aligned with the direction of the electric field, so that the piezoelectric property is imparted to the flexible pressure-sensitive body 102.
JP-A-62-230071 JP 2002-280633 A "Piezoelectric composite material consisting of piezoelectric ceramic powder and synthetic rubber" Powder and Industry, Vol. 22, No. 1, 1990, p50 / 56

  However, in the conventional polarization method of the cable-shaped pressure sensor, when a high voltage is applied between the core electrode 101 and the outer electrode 103, defects such as minute cracks and holes in the flexible pressure sensitive body 102 are obtained. Is present, a micro discharge is generated at the defective portion.

  By this minute discharge, the constituent material of the flexible pressure-sensitive body 102 is thermally evaporated and scattered, and the core electrode 101 and the outer electrode 103 are short-circuited, and a high voltage can be applied between the core electrode 101 and the outer electrode 103. Therefore, the flexible pressure sensitive body 102 cannot be polarized.

Further, when the flexible pressure-sensitive body 2 is disposed on the block-shaped conductor 5 and polarized while being moved by the moving means 7, the block-shaped conductor 5 and the flexible pressure-sensitive body 2 are arranged. There is a problem that the production efficiency is lowered because the contact resistance is large and the moving speed cannot be increased.

  The present invention solves such a conventional problem, and an object of the present invention is to ensure polarization of a flexible pressure-sensitive body and improve productivity and reliability.

  In order to solve the above-described conventional problems, a flexible pressure-sensitive body provided around a core electrode, and a plurality of ball chains made of a conductive material, arranged to contact the entire circumference of the flexible pressure-sensitive body. A polarization electrode constituted by: a core electrode and a DC voltage generating means connected to the polarization electrode; a movement means for moving the flexible pressure sensitive member in a passage; a heating means for heating the polarization electrode; Generated from the flexible pressure sensitive body during operation of the stress applying means for applying a physical stress to the flexible pressure sensitive body, a charge removing means for removing charges charged in the flexible pressure sensitive body, It comprises output detection means for detecting the output.

  As a result, since the ball chain can be brought into contact with the flexible pressure-sensitive body uniformly, it becomes possible to uniformly polarize the entire circumference. For this reason, there are no unpolarized portions, and stable characteristics without characteristic variations can be obtained.

  The cable-shaped pressure sensor of the present invention prevents the entire flexible pressure sensing element from being unable to polarize even if a defect exists, and detects whether the flexible pressure sensing element is normally polarized. Therefore, it is possible to immediately detect the abnormality of the polarization device and the abnormality of the flexible pressure-sensitive body, and the productivity and reliability can be improved.

  1st invention was comprised by the several ball chain which is arrange | positioned so that it may contact the perimeter of the said flexible pressure-sensitive body around the said core pressure electrode, and the said flexible pressure-sensitive body, and consists of an electroconductive material. Polarizing electrode, DC voltage generating means connected to the core electrode and the polarizing electrode, moving means for moving the flexible pressure sensitive body in a passage, heating means for heating the polarizing electrode, and flexible pressure sensitive A charge removing means for removing a charge charged on the body; a stress applying means for applying a physical stress to the flexible pressure sensitive body; and an output generated from the flexible pressure sensitive body during the operation of the stress applying means. And output detection means.

  As a result, the flexible pressure-sensitive body can be polarized uniformly, and whether or not it is normally polarized can be detected during the polarization, so that the abnormality of the polarization device and the abnormality of the flexible pressure-sensitive body can be immediately detected. It is possible to improve productivity and reliability.

  According to a second aspect of the invention, in particular, in the first aspect of the invention, the electrification removing means has a simple structure by connecting a conductor provided so as to be in contact with the entire surface of the flexible pressure-sensitive body to the ground potential. The charge charged on the flexible pressure sensitive body can be removed.

  According to a third aspect of the invention, in particular, in the second aspect of the invention, the contact resistance between the conductor and the flexible pressure sensitive body can be reduced by configuring the conductor with a conductive fiber. The occurrence of scratches or the like can be prevented, so that the reliability can be improved.

  In the fourth invention, in particular, in the second invention, the contact resistance between the conductor and the flexible pressure-sensitive body can be reduced by configuring the conductor with a plurality of ball chains made of a conductive material. Since the occurrence of scratches on the flexible pressure sensitive body can be prevented, the reliability can be improved.

Furthermore, since the conductor has the same shape as that of the polarization electrode, it is only necessary to connect a part of the polarization electrode to the ground potential. Therefore, it is possible to easily remove the electric charge charged in the flexible pressure sensitive body.

  According to a fifth aspect of the invention, in particular, in the first aspect of the invention, the stress applying unit can apply stress to the flexible pressure sensitive body with a simple configuration by directly hitting the flexible pressure sensitive body.

  According to a sixth aspect of the present invention, in particular, in the first aspect, the stress applying means applies a predetermined air pressure to the flexible pressure sensitive body, thereby applying stress to the flexible pressure sensitive body with a simple configuration. be able to.

  According to a seventh aspect of the invention, in particular, in the first aspect of the invention, the stress applying means can apply the stress to the flexible pressure sensitive body with a simple configuration by dropping the object from a predetermined height. .

  According to an eighth aspect of the invention, in particular, in the first aspect of the invention, the output detecting means is composed of a metal material in contact with the flexible pressure-sensitive body and a core electrode, so that the flexible pressure-sensitive force accompanying the application of stress by the stress applying means. The output of the body can be easily detected.

  In the ninth aspect of the invention, in particular, in the first aspect of the invention, it is possible to quickly detect an abnormality by providing an alarm generation unit that determines that an abnormality occurs when the output of the output detection unit is out of the specified range and issues an alarm. , Improve productivity and reliability.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, this invention is not limited by this embodiment.

(Embodiment 1)
In FIG. 1, the cable-shaped pressure sensor is formed with a flexible pressure-sensitive body 2 that is provided around the core electrode 1.

  For the core electrode 1, a coiled metal wire, a wire bundled with fine metal wires, or the like is used.

  As the flexible pressure-sensitive body 2, a polymer material in which a piezoelectric material such as lead zirconate titanate is combined with a polymer base material such as epoxy resin, urethane resin, chloroprene resin, chlorinated polyethylene, or silicon resin is used.

  The flexible pressure-sensitive body 2 is disposed so as to be in contact with the entire circumference of the polarization electrode 3 composed of a plurality of ball chains composed of a conductive material.

  As the polarization electrode 3, iron, stainless steel, copper, brass, aluminum or the like is used.

  In the present embodiment, the polarizing electrode 3 has a configuration in which 10 pieces of aluminum balls of φ1.5 are arranged in the vertical direction and 30 pieces are arranged vertically and 10 pieces are arranged horizontally.

  In addition, the diameter of the flexible pressure sensitive body 2 at this time was 1.6 mm. Further, a heating means 4 for heating the flexible pressure sensitive body 2 by heating the polarization electrode 3 is provided below the polarization electrode.

  Polarization can be performed efficiently by polarizing the polarization body 3 while heating the flexible pressure sensitive body 2.

Further, a rotating drum was used as the moving means 5 for moving the flexible pressure sensitive body 2. By changing the rotation speed of the rotating drum, it is possible to easily adjust the time during which the flexible pressure-sensitive body 2 is disposed in the polarization electrode 3, in other words, the polarization time.

  Moreover, by providing the moving means 5, it can automate and can improve a yield.

  Moreover, the polarization electrode 3 is electrically connected by the lead wire 6b. The lead wire 6a is electrically connected to the positive or negative electrode of the DC voltage generating means 7, and the core electrode 1 is electrically connected to the other pole of the DC voltage generating means 7 through the lead wire 6a.

  In this way, a high voltage is applied between the core electrode 1 and the polarization electrode 3 by the DC voltage generating means 7, so that the flexible pressure sensitive body 2 is polarized.

  In the present embodiment, polarization was performed at an applied voltage of 7 kV / mm.

  When a minute defect is included in the flexible pressure-sensitive body 2 and the portion is disposed on the polarization electrode 13, a high current is generated between the polarization electrode 13 and the core electrode 11 due to a minute discharge generated at the defect portion. Although it cannot be polarized because it flows and is short-circuited, if the defect portion is detached from the polarization electrode 13 and there is no defect in the flexible pressure-sensitive body 12 disposed on the polarization electrode 13, the polarization electrode 13 and the core electrode 11 Since the insulation between them is restored again, polarization becomes possible.

  As described above, according to the polarization device of the present embodiment, polarization cannot be performed only when a portion including a defect is disposed on the polarization electrode 13, but polarization is possible in other cases.

  Therefore, the flexible pressure-sensitive body 12 cannot be polarized as a whole due to the presence of defects.

  Further, since the polarization electrode 13 has a coil shape, the contact area with the flexible pressure-sensitive body 2 is reduced and the contact resistance is reduced as compared with the case where the conventional block-shaped conductor 105 shown in FIG. 7 is used. it can.

  In particular, when the DC voltage generating means 7 is operated, a high voltage is applied between the core electrode 1 and the polarization electrode 3, and the flexible pressure sensitive body 2 is pulled in the direction of the polarization electrode 3. The contact resistance between the flexible pressure sensitive bodies 2 will increase.

  In the case of using the conventional polarization device shown in FIG. 7, since the flexible pressure sensitive body 102 is polarized on the entire surface of the block-like conductor 105, even if the flexible pressure sensitive body 102 is pulled using the moving means 107, Since the contact resistance is large, it is difficult to move, and when it is pulled forcefully, the surface of the flexible pressure-sensitive body 102 is scratched by friction. In addition, this scratch causes a decrease in insulation of the flexible pressure-sensitive body 102, and the scratch portion is discharged during polarization, leading to a decrease in yield.

  On the other hand, in the polarization device of the present embodiment, since the polarization electrode 3 has a ball chain shape, the contact resistance can be reduced, and even if the flexible pressure sensitive body 2 is pulled by the moving means 5, this flexible pressure sensitive pressure sensor can be used. The surface of the body 2 was not scratched by friction. For this reason, the yield fall by a damage | wound can be suppressed.

  Furthermore, since the contact resistance is suppressed, the speed of the moving means 5 can be improved and the production efficiency can be improved.

Further, the conventional block-shaped conductor 105 of FIG. 7 is formed in a concave shape with a groove to facilitate disposing the flexible pressure-sensitive body 102. In this case, the block-shaped conductor 105 and the flexible pressure-sensitive body are provided. There is a surface that does not face 102, and the flexible pressure-sensitive body 102 at that portion cannot be polarized.

  For this reason, characteristic variation occurs in the flexible pressure-sensitive body 102, which may cause a decrease in characteristics and reliability.

  However, in the present embodiment, the polarization electrode 3 has a ball chain shape, and the polarization electrode 3 is disposed on the outer periphery of the flexible pressure-sensitive body 2, so that a portion that cannot be polarized does not occur.

  As a result of forming an external electrode and outer skin on the flexible pressure sensitive body 102 polarized by the conventional polarization device shown in FIG. 7 and completing vibration as a cable-shaped pressure sensor, and measuring the output voltage generated at that time, An output difference of about 1.5 times occurred between the portion not facing the block-like conductor 105 and the portion facing the block-like conductor 105.

  However, in the case of using the polarization device of the present embodiment, the difference in output was hardly seen no matter which part was applied with vibration.

  In addition, when the conventional block-shaped conductor 105 of FIG. 7 is provided with a lid for soaking or when the passage is made a hole, if the flexible pressure-sensitive body 102 is heated too much, the flexible pressure-sensitive body Volatile components contained in the body 102 adhere to the passage of the block-like conductor 105, and the polarization voltage is applied to the flexible pressure-sensitive body 102 through the attached matter, so that there is a problem that the polarization efficiency is lowered. It was.

  However, in the present embodiment, since the polarization electrode 3 has a ball chain shape, it is possible to prevent the volatile component from being diffused into the outside air and adhering to the polarization electrode 3, and the output of the DC voltage generating means 7 is hindered by the adhering matter. Thus, efficient polarization is possible.

  Further, once the flexible pressure-sensitive body 2 is arranged in the polarization electrode 3, it is only necessary to connect the core electrodes 1 to each other when the next lot is polarized, and it is necessary to arrange in the polarization electrode 3 again. There is no.

  For this reason, the flexible pressure-sensitive body 2 can be easily disposed.

  In the first embodiment, the core electrode 1 of the flexible pressure-sensitive body 2 is set to the ground potential, and a DC voltage is applied between the core electrode 1 and the polarization electrode 3.

  By connecting in this way, it is possible to limit the direct-current high voltage portion that is dangerous to the human body to the polarization electrode 3, and to ensure safety to the human body.

  Furthermore, in order to determine whether or not the flexible pressure sensitive body 2 is normally polarized, the polarization device of the present embodiment includes a stress applying means 8 that applies physical stress to the flexible pressure sensitive body 2. Provided is an output detecting means 9 for detecting an output generated from the flexible pressure sensitive body 2 when the stress applying means 8 is operated.

  The stress applying means 8 is configured to apply the stress by using the motor 10 so that the header 11 directly contacts the flexible pressure-sensitive body 2 and the header 11 strikes at constant intervals with a constant stroke.

  The output detecting means 9 is composed of a metal material 12 in contact with the flexible pressure sensitive body 2 and the core electrode 1, and detects the electric charge generated when stress is applied to the flexible pressure sensitive body 2 as a voltage value. ing.

  In the present embodiment, the voltage value is detected, but the capacitance and the charge amount may be directly detected.

  In this stress application configuration, since the flexible pressure sensitive body is always moved by the moving means, the sense that the polarization could not be normally performed at the same time when the stress was applied and the output of the flexible pressure sensitive body was detected. It is possible to accurately detect the site of the pressure body.

  However, the surface of the flexible pressure sensitive body 2 immediately after polarization is charged by the influence of the high voltage applied by the DC voltage generating means 7 and is generated from the flexible pressure sensitive body 2 by the stress applying means 8 as it is. When the output is detected, an error occurs in the output due to the influence of charging.

  For this reason, it is necessary to remove the electric charge charged on the flexible pressure-sensitive body 2 before operating the stress applying means 8. In this embodiment, the charge removing means 13 is provided to charge the surface of the flexible pressure-sensitive body 2. It was set as the structure removed.

  The electrification removing means 13 is configured to connect a conductor provided so as to be in contact with the entire surface of the flexible pressure-sensitive body to the ground potential.

  In the present embodiment, the conductor 14 of the charge removing means 13 is made of a conductive fiber, and the charged charge is removed by connecting the conductive fiber to the ground potential.

  By adopting this configuration, the output variation can be reduced by about 33% because there is no influence of the charged electric charge.

  Further, by configuring the conductor 14 with a conductive fiber, the contact resistance between the conductor 14 and the flexible pressure-sensitive body 2 can be reduced, and the occurrence of damage to the flexible pressure-sensitive body 2 can be prevented. Therefore, reliability can be improved.

  In the present embodiment, the conductive fibers are used as the charge removing means 13, but the present invention is not limited to this as long as it is configured to remove the charges charged in the flexible pressure sensitive body 2.

  For example, as shown in FIG. 2, a ball chain-like electrode similar to the polarization electrode 3 may be provided as the conductor 14, and this electrode may be connected to the ground potential.

  In the case of this configuration, since the conductor 14 has the same shape as the polarization electrode 3, it is only necessary to connect a part of the polarization electrode 3 to the ground potential. Therefore, the charge charged on the flexible pressure-sensitive body 2 can be easily removed. It becomes possible.

  Further, by forming the ball chain shape, the contact resistance between the conductor 14 and the flexible pressure sensitive body 2 can be reduced, and the occurrence of scratches on the flexible pressure sensitive body 2 can be prevented. Can be improved.

  By adopting this configuration, the output corresponding to the applied stress of the stress applying means 8 can be detected by the output detecting means 9, and the reliability of the performance evaluation of the flexible pressure sensitive body 2 can be improved. Became.

  In particular, in this embodiment, since the polarization electrode 3 has a ball chain shape, the flexible pressure-sensitive body 2 can be polarized more uniformly than the conventional polarization device shown in FIG. Electric charges are easily accumulated on the entire surface of the pressure-sensitive pressure body 2.

  Therefore, it is necessary to remove the charge accumulated by the charge removing means 13.

  In the polarization device of the present embodiment, the output signal of the output detection means 9 of the flexible pressure-sensitive body 2 that has been normally polarized is not less than a specified value, and a signal within a specified range could be obtained. In the case of the flexible pressure-sensitive body 2 that is not provided, the output of the output detection means 9 could not obtain a specified value.

  As described above, according to the polarizing device of the present invention, after the flexible pressure sensitive body is polarized, stress is applied to the flexible pressure sensitive body 2 by the stress applying means 8 and a signal generated at that time is detected. It is possible to detect whether or not the flexible pressure-sensitive body 2 is normally polarized.

  For this reason, the abnormality of the polarization device and the abnormality of the flexible pressure-sensitive body 2 can be detected immediately, and the productivity and reliability can be improved.

(Embodiment 2)
FIG. 3 shows the second embodiment of the present invention. The difference from the first embodiment is that the stress applying means 8 applies a predetermined air pressure to the flexible pressure-sensitive body 2, so that the flexible pressure-sensitive body is shown. This is a point where stress is applied to 2.

  In addition, the same code | symbol is attached | subjected about what performs the effect | action similar to FIG. 1, 2, and the thing of Embodiment 1 is used for concrete description.

  In the present embodiment, the stress applying means 8 includes a pump 15 that applies pressure, and a pipe 16 that transmits air from the pump 15 to the flexible pressure-sensitive body 2.

  By adopting this configuration, it is possible to apply stress to the flexible pressure sensitive body 2 with a simple configuration, and therefore it is possible to detect whether or not the flexible pressure sensitive body 2 is normally polarized.

  For this reason, it is possible to immediately detect the abnormality of the polarization device and the abnormality of the flexible pressure-sensitive body, and the productivity and reliability can be improved.

  In addition to applying air pressure as shown in FIG. 4, a ball is disposed as an object 17 in the pipe 16 and dropped from a predetermined height to apply stress to the flexible pressure-sensitive body 2, After application, the dropped ball is sucked by the pump 15 and returned to a predetermined height. Also in this configuration, the same effect as in the first embodiment and when air pressure is applied can be obtained.

(Embodiment 3)
FIG. 5 shows the third embodiment of the present invention. The difference from the first and second embodiments is that when the output of the output detection means 9 is out of the specified range, it is judged as abnormal and an alarm is issued. The alarm generation means 18 is provided.

  In addition, the same code | symbol is attached | subjected about what performs the effect | action similar to FIG. 1, 2, and the thing of Embodiment 1, 2 is used for concrete description.

  By adopting this configuration, it is possible to quickly detect an abnormality and improve productivity and reliability. Further, in the present embodiment, the abnormality is notified by the alarm generation means 18, but the abnormality may be detected and the DC voltage generation means 7 may be stopped.

When the output is determined to be abnormal and the output deviates from the specified range, the output of the DC voltage generating means 7 deviates from the predetermined value, or the wire diameter of the flexible pressure sensitive body 2 is within the predetermined range. For example, if the output of the DC voltage generating means 7 is out of a predetermined value, the wire diameter of the flexible pressure-sensitive body 2 is returned to the predetermined value. If it is out of the range, it is possible to take measures such as adjusting the output of the DC voltage generating means 7 in accordance with the wire diameter.

  As described above, the polarization device for the cable-shaped pressure sensor according to the present invention prevents the entire flexible pressure sensing element from being polarized even if a defect exists, and prevents the flexible pressure sensing element from conducting. Since the friction between the bodies can be reduced, the moving speed of the flexible pressure sensitive body can be improved, productivity can be improved, and defects caused by rubbing the flexible pressure sensitive body due to friction can be prevented. It can be polarized stably.

  Furthermore, since it is possible to detect whether or not the flexible pressure sensitive body is normally polarized, it is possible to immediately detect the abnormality of the polarization device and the abnormality of the flexible pressure sensitive body, thereby improving productivity and reliability. It is a polarization device. For this reason, it is applicable not only to a cable-shaped pressure sensor but also to polarization of a piezoelectric body that requires polarization. For this reason, it is applicable not only to a cable-shaped pressure sensor but also to polarization of a piezoelectric body that requires polarization.

FIG. 1 is an external perspective view showing a configuration of a polarization device in Embodiment 1 of the present invention. FIG. 3 is an external perspective view showing the configuration of another polarization device according to Embodiment 1 of the present invention. External appearance perspective view which shows the structure of the polarization apparatus in Embodiment 2 of this invention. External appearance perspective view which shows the structure of the other polarizing apparatus in Embodiment 2 of this invention External appearance perspective view which shows the structure of the polarization apparatus in Embodiment 3 of this invention. External view of conventional piezoelectric cable sensor Outline drawing showing the configuration of a conventional polarization device

Explanation of symbols

1 core electrode 2 flexible pressure sensitive body
DESCRIPTION OF SYMBOLS 3 Polarizing electrode 4 Heating means 5 Moving means 7 DC voltage generating means 8 Stress applying means 9 Output detecting means 12 Metal material 13 Charge removing means 14 Conductor 18 Alarm generating means

Claims (9)

A flexible pressure-sensitive body provided around the core electrode; a polarization electrode that is disposed so as to be in contact with the entire circumference of the flexible pressure-sensitive body and is formed of a plurality of ball chains made of a conductive material; and the core DC voltage generating means connected to the electrode and the polarizing electrode, moving means for moving the flexible pressure sensitive body in the passage, heating means for heating the polarizing electrode, and charge charged to the flexible pressure sensitive body A charge removing means for removing, a stress applying means for applying a physical stress to the flexible pressure sensitive body, and an output detecting means for detecting an output generated from the flexible pressure sensitive body during operation of the stress applying means. Cable pressure sensor polarization device. 2. The polarization device for a cable-shaped pressure sensor according to claim 1, wherein the electrification removing means is configured to connect a conductor provided so as to be in contact with the entire surface of the flexible pressure-sensitive body to a ground potential. The polarization device for a cable-shaped pressure sensor according to claim 2, wherein the conductor is made of a conductive fiber. The polarization device for a cable-shaped pressure sensor according to claim 2, wherein the conductor is composed of a plurality of ball chains made of a conductive material. 2. The polarization device for a cable-shaped pressure sensor according to claim 1, wherein the stress applying means is configured to apply stress by directly hitting a flexible pressure sensitive body. 2. The polarization device for a cable-shaped pressure sensor according to claim 1, wherein the stress applying means applies a predetermined air pressure to the flexible pressure sensitive body. 2. A polarization device for a cable-shaped pressure sensor according to claim 1, wherein the stress applying means drops the object from a predetermined height and applies the object to the flexible pressure sensitive body. 2. The polarization device for a cable-shaped pressure sensor according to claim 1, wherein the output detection means is constituted by a metal material in contact with the flexible pressure sensitive body and a core electrode, and detects an output between the metal material and the core electrode. 2. The polarization device for a cable-like pressure sensor according to claim 1, further comprising alarm generating means for determining that an abnormality occurs when the output of the output detecting means is out of a specified range.