CN113611062A

CN113611062A - Passive tension fence intrusion detection system

Info

Publication number: CN113611062A
Application number: CN202111161469.XA
Authority: CN
Inventors: 宋源辉
Original assignee: Nantong Weijiedun Intelligent Technology Co ltd
Current assignee: Nantong Weijiedun Intelligent Technology Co ltd
Priority date: 2021-09-30
Filing date: 2021-09-30
Publication date: 2021-11-05
Anticipated expiration: 2041-09-30
Also published as: CN113611062B

Abstract

The invention discloses a passive tension fence intrusion detection system, which comprises a passive detector, a tension barbed wire and a signal wire, wherein the tension barbed wire is arranged on the passive detector; in a normal state, the tension barbed wire keeps fixed tensioning tension, the passive detector keeps a tension balance state, and a normally open state is formed between the movable contact and the static contact at the lower part of the sensing main shaft; when the sensing main shaft moves relatively, the movable contact and the static contact are triggered, so that an alarm signal is generated after the signal wire is closed. The invention is a pure mechanical structure, the passive detector does not contain any electronic element, and the design value of the mean time to failure of the product is 2500 ten thousand hours; has the advantages of low cost, long service life, wide application range and the like.

Description

Passive tension fence intrusion detection system

Technical Field

The invention relates to the technical field of tension fences, in particular to a passive tension fence intrusion detection system.

Background

Along with the continuous improvement of living standard of people, the safety is more and more emphasized by people, and a plurality of safety protection products are generated, and are widely applied to occasions such as residential districts, enterprises and public institutions, government offices, schools, factories, transformer substations, railways, key protection areas and the like. At present, products such as a vibrating cable and an infrared correlation product are easily affected by an external environment to cause false alarm, if the vibrating cable is easily affected by vehicles, thunder and lightning, the requirement of the infrared detection product on the environment is high, and when the environment changes, if branches shield, strong light irradiates, animals come in and go out or the environment is strong wind and rain, the products are easy to generate false alarm information, the false alarm rate is high, and the service life is short.

In important areas such as airports, military bases, weapons and ammunition stores, prisons, bank vaults, museums, power plants, oil depots, etc., in order to prevent illegal intrusion and various destructive activities, conventional precautions are to provide barriers or obstacles (such as iron fences, wire fencing nets, etc.) at the peripheral peripheries of the areas, and to arrange personnel to strengthen patrol.

In the living field, safety is more and more emphasized by people, and a plurality of safety protection products are generated along with the safety protection, and are widely applied to occasions such as residential districts, enterprises and public institutions, government offices, schools, factories, transformer substations, railways, key protection areas and the like.

The prior art perimeter detection systems mainly include the following systems: electronic fences, infrared correlation, vibrating cables, leaky cables, vibrating optical fibers, and the like. Products such as fence, infrared correlation, vibrating cable, reveal the cable receive external environment's influence and the wrong report easily, if vibrating cable receives vehicle, thunder and lightning easily and the wrong report, the requirement of infrared detection product to the environment is higher, when the environment changes, under the circumstances such as branch shielding, strong light shines, has the animal to come in and go out or strong wind and heavy rain, these produce the wrong report information easily, the wrong report rate is very high moreover, the life cycle is short. And these products are all active products that require electrical energy to maintain their basic operation. The vibration optical fiber has certain advantages, but has high cost and is easily corroded by sewage, thereby affecting the reliability of a detection system.

The applicant has invented various fence intrusion detection systems, such as an intrusion detection grid system described in chinese patent CN202020130388.8 and a tension fence intrusion prevention detection system described in chinese patent CN201922011016.3, which all have the problems of power supply requirement, high cost, limited applicable area, etc.

Disclosure of Invention

Aiming at the problems in the prior art, the invention aims to provide a passive tension fence intrusion detection system which does not need power supply, has high sensitivity, low false alarm rate and low cost.

In order to achieve the purpose, the passive tension fence intrusion detection system comprises a passive detector, a tension barbed wire and a signal wire, wherein the tension barbed wire is arranged on the passive detector;

the passive detector comprises a shell, a sensing main shaft and a static contact body, wherein the upper end and the lower end of the passive detector are respectively and fixedly connected with an upper tensile barbed wire and a lower tensile barbed wire, a viscoelastic inverter material body is arranged at the lower part in the shell, and the lower part of the static contact body is wrapped by the viscoelastic inverter material body; the sensing main shaft and the static contact body are respectively communicated with the signal wire through lead wires;

in a normal state, the tension barbed wire keeps fixed tensioning tension, the passive detector keeps a tension balance state, and a normally open state is formed between the movable contact and the static contact at the lower part of the sensing main shaft; when the sensing main shaft moves relatively, the movable contact and the static contact are triggered, so that an alarm signal is generated after the signal wire is closed;

the viscoelastic inversion material body is a high-molecular polymer material formed by polydimethylsiloxane, a macromolecular polymer is formed by coordination bonds among polydimethylsiloxane molecules, and a stressed part of the macromolecular polymer forms a firm molecular net structure under the action of a rapid external force, so that the position of a static contact body is relatively fixed.

Further, the passive tension fence intrusion detection system further comprises: the device comprises an anchor post, a detector post, a spiral post and a tensioner, wherein the anchor post is arranged at two ends of a defense area, and two ends of a plurality of tension barbed steel wires are fixed on a bronze easy-to-fold piece of the anchor post through the tensioner; a plurality of spiral columns are arranged between the two anchor columns at intervals and in parallel, and the middle parts of the tensile barbed wires are supported and positioned on the spiral columns; and the central positions of the two anchor posts are provided with detector posts, and the passive detectors are arranged in the detector posts.

Furthermore, the passive detector comprises an upper shell and a lower shell, wherein the upper shell is made of elastic materials, the lower shell is made of hard materials, the sensing spindle is fixed on the upper shell, and the elastic materials of the upper shell do not obstruct the relative movement of the sensing spindle.

Furthermore, the upper shell comprises an upper main body and a ring wall extending downwards, the lower shell is of a concave structure, fixing units matched with each other are arranged between the outer wall of the lower shell and the inner wall of the ring wall, and the upper shell and the lower shell are installed and fixed through the fixing units after the lower shell is inserted upwards into the ring wall.

Further, the sensing main shaft is fixed on the upper main body, and the lower end of the sensing main shaft is provided with a small-diameter probe; the viscoelastic inverter material body is arranged at the bottom of the concave structure of the lower shell, the static contact body comprises a conical base and a cup body, the conical base is wrapped by the viscoelastic inverter material body, the probe is inserted into the cup body, and a safety gap is formed between the probe and the inner wall of the cup body.

Furthermore, when the tensioning tension between the tension barbed wires is unbalanced, the viscoelastic inverter material body is stressed and then becomes a temporary solid body to relatively fix the position of the conical base, meanwhile, the upper shell is deformed, and after the sensing spindle relatively moves, the probe is triggered by the inner wall of the cup body, so that an alarm signal is generated after the signal wire is closed.

Furthermore, a plurality of passive detectors are respectively connected in parallel on the signal line through lead wires; the upper portion of sensing main shaft through first lead wire with the signal line intercommunication, the cup through the second lead wire with the signal line intercommunication, be provided with the lead wire groove between the outer wall of lower casing and the inner wall of rampart, the second lead wire is drawn forth through the lead wire groove outwards.

Furthermore, an upper wire clamp is arranged at the outer end part of the sensing main shaft, and the tensile barbed wire is fixedly connected with the sensing main shaft through the upper wire clamp.

Furthermore, the bottom of the lower shell is provided with a stud, a lower wire clamp is arranged on the stud, and the tension barbed wire is fixedly connected with the lower shell through the lower wire clamp.

Furthermore, the distance between two adjacent tension barbed steel wires is 90-200m, wherein the distance between the tension barbed steel wires below 1m from the ground is less than or equal to 100mm, the distance between the tension barbed steel wires 1m-2m from the ground is 100mm-200mm, and the distance between the tension barbed steel wires at the inclined support position above 2m is 200 mm.

Furthermore, the tension barbed steel wires are fixed through the anchor posts and tensioned through a tensioner, and the fixed tension value of each tension barbed steel wire is 35-55 kgf.

Further, when the tension barbed wire horizontally moves along the fence direction at a speed lower than 1 mm/min, the viscoelastic inverter material body keeps fluidity and plasticity, the sensing main shaft and the static contact body synchronously generate deformation displacement, the sensing main shaft and the static contact body cannot be triggered to be closed, and no alarm signal is generated; when the external force applied by an intruder by the tension barbed wire exceeds 10kgf, the tension barbed wire drives a part of the passive detector to rapidly move, the speed exceeds 1 mm/min, the property of the viscoelastic inversion material body is inverted and changed into a temporary solid body, so that the static contact body is fixed, the sensing main shaft and the static contact body are closed, and an alarm signal is generated.

The passive tension fence intrusion detection system is of a pure mechanical structure, the passive detector does not contain any electronic component, and the design value of Mean Time Between Failure (MTBF) of a product is 2500 ten thousand hours; generally, in a system with a defense area of 3 and 60 meters of barbed steel wires with the height of 2.5 meters and the tension of 24 barbed steel wires, the design value of the integral Mean Time Between Failures (MTBF) is more than or equal to 76 ten thousand hours; has the advantages of low cost, long service life, wide application range and the like.

Drawings

FIG. 1 is a schematic structural diagram of a passive tension fence intrusion detection system according to the present invention;

FIG. 2 is a schematic view of the principle of alarming when a tension fence is stressed;

fig. 3 is a schematic structural diagram of the passive detector 2.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

The following detailed description of embodiments of the invention refers to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.

As shown in fig. 1, 2 and 3, the passive tension fence intrusion detection system of the present invention includes an anchor column 1, a passive detector 2, a tension barbed wire 3, a detector column 4, a spiral column 5, a tensioner 6 and a signal line 7. The passive tension fence intrusion detection system is of a pure mechanical stress structure, does not have any electronic element, and can induce tension force to cause the internal contact of the passive detector 2 to form a short circuit alarm signal.

The passive tension fence intrusion detection system is defense area type intrusion alarm equipment, the longest defense area is 60m, and two anchor posts 1, a plurality of passive detectors 2, a plurality of tension barbed steel wires 3, a detector post 4, a plurality of spiral posts 5 and a plurality of tensioners 6 are arranged in each defense area. The anchor posts 1 are made of 304 or 316 stainless steel and are arranged on the ground or walls at two ends of a defense area; the tension barbed steel wire 3 is made of 304 or 316 stainless steel, and two ends of the tension barbed steel wire 3 are fixed on a bronze easy-folding plate (not shown) of the anchor post 1 through a tensioner 6; a plurality of spiral columns 5 are arranged between the two anchor columns 1 at intervals in parallel, the spiral columns 5 are made of 304 or 316 stainless steel, are parallel to the anchor columns and are uniformly arranged in a defense area, and the middle parts of the tensile barbed steel wires 3 are supported and positioned on the spiral columns 5; the detector column 4 is made of aluminum-magnesium alloy and is positioned in the center of a defense area, namely the detector column 4 is arranged at the center of the two anchor columns 1, and the plurality of passive detectors 2 are arranged in the detector column 4. The passive detectors 2 do not use a power supply, and are fixed in the detector columns 4 through bolts, and the tension barbed wire 3 passes through a wire clamp on each passive detector 2 to be tightly connected to the passive detectors 2.

The passive detector 2 comprises a shell, a sensing main shaft 8 and a static contact body 9, the shell comprises an upper shell 10 and a lower shell 11, the upper shell 10 is made of elastic materials, the lower shell 11 is made of hard materials, in practical application, the upper shell 10 is made of weather-resistant silicone rubber which is rich in elasticity, the action of the sensing main shaft 8 can be well adapted, the lower shell 11 is made of weather-resistant PA6, and the firm characteristic of the lower shell ensures that an internal contact is not influenced by the outside. The sensing spindle 8 is fixed to the upper housing 10, and the elastic material of the upper housing 10 does not hinder the relative movement of the sensing spindle 8.

The upper casing 10 comprises an upper main body 12 and a ring wall 13 extending downwards, the lower casing 11 is of a concave structure, a fixing unit 14 matched with each other is arranged between the outer wall of the lower casing 11 and the inner wall of the ring wall 13, and the upper casing 10 and the lower casing 11 are installed and fixed through the fixing unit 14 after the lower casing 11 is upwards inserted into the ring wall 13. The fixing unit 14 may be a snap structure.

The sensing main shaft 8 is fixed on the upper main body 12, the lower end of the sensing main shaft 8 is provided with a small-diameter probe 15, the sensing main shaft 8 is made of 316 stainless steel, and the probe 15 can be directly machined through a metal material of the sensing main shaft 8. The probe 15 is the moving contact of the sensing spindle 8.

The bottom of the concave structure of the lower shell 11 is provided with a viscoelastic inversion material body 16, and the lower part of the static contact body 9 is wrapped by the viscoelastic inversion material body 16. The static contact body 9 comprises a conical base 17 and a cup body 18, and the static contact body 9 is also made of metal materials. Wherein, conical base 17 is wrapped up by the contravariant material body of viscoelastic 16, and probe 15 cartridge is in cup 18, and the external diameter of probe 15 is less than the internal diameter of cup 18, is provided with the safety clearance between the inner wall of probe 15 and cup 18, and under normal condition, both are in normally open state. Wherein, the cup body 18 is the stationary contact of the stationary contact 9.

In a normal state, the tension barbed wire 3 keeps fixed tensioning tension, the passive detector 2 keeps a tension balance state, and a probe 15 at the lower part of the sensing main shaft 8 and the static contact 9 are in a normally open state; in an abnormal state, the tensioning tension among the tension barbed wires 3 is unbalanced, the viscoelastic inversion material body 16 is changed into a temporary solid body after being stressed to relatively fix the position of the static contact body 9, and after the sensing main shaft 8 moves relatively, the probe 15 and the static contact body 9 are triggered to generate an alarm signal after the signal wire 7 is closed.

The viscoelastic material 16 is mainly composed of polydimethylsilane and is composed of a polymer material containing an auxiliary component such as a solvent or a stabilizer. The viscoelastic inversion material body forms a macromolecular polymer through coordination bonds among main component material molecules, and forms a material which is sensitive to stress change and can invert between viscosity and elasticity. The material is actually expressed in that when an external force with a lower speed acts on the viscoelastic inverse material body, the structure of a coordination bond of a polymer is changed, so that the material is expressed as flow and plasticity with viscosity, and the acting force is absorbed; when an external force with higher speed acts on the viscoelastic inverse material body, a stress part of the material can form a firm molecular network structure, and the molecular network structure enables the material to be represented as a semi-solid body with temporary elasticity. In addition, in order to adapt to high-temperature and high-cold regions and long-term use, the viscoelastic inverter material body 16 needs to ensure the durability and stability of the viscoelastic inverter characteristics and slow down the aging of the material by adjusting the proportion of the main components and the proportion of the auxiliary components of the viscoelastic inverter material body.

In the invention, a plurality of passive detectors 2 are respectively connected in parallel on a signal wire 7 through lead wires, and an output signal wire of the signal wire 7 can be connected with an alarm device to provide an intrusion alarm signal for the alarm device; or the output signal line of the signal line 7 is connected with an alarm host to provide an alarm signal for the security system. The upper part of the sensing main shaft 8 is communicated with the signal wire 7 through a first lead 19, the cup body 18 is communicated with the signal wire 7 through a second lead 20, a lead slot 21 is arranged between the outer wall of the lower shell 11 and the inner wall of the annular wall 13, and the second lead 20 is led out outwards through the lead slot 21.

When the tension between the tension barbed wires 3 is unbalanced, the viscoelastic inverter material body 16 is stressed to be changed into a temporary solid body to relatively fix the position of the conical base 17, meanwhile, the upper shell 10 is made of an elastic material, the upper shell 10 deforms, and after the sensing spindle 8 relatively moves, the probe 15 is directly triggered with the inner wall of the cup body 18, namely, the movable contact and the fixed contact are closed, so that an alarm signal is generated after the signal wire 7 is closed.

The body 16 of viscoelastic material is sensitive to stress changes and has viscoelastic inversion properties. The body of viscoelastic material 16 is flowable and malleable in the unstressed state and the body of viscoelastic material 16 transforms into a temporary solid body with resiliency in the stressed state.

In the invention, the viscoelastic inversion material body 16 in the passive detector 2 can adapt to extremely slow movement caused by thermal expansion and cold contraction, namely, the tensile barbed wire 3 horizontally moves at a speed lower than 1 mm/min along the fence direction, at the moment, the viscoelastic inversion material body 16 wrapping the static contact body 9 can adapt to the extremely slow movement, and the viscoelastic inversion material body 16 keeps fluidity and plasticity, so that the static contact body 9 generates displacement due to the deformation of the viscoelastic inversion material body 16, the static contact body 9 cannot be closed with the probe 15, and an alarm signal is not generated.

When the external force applied by an intruder on the tensile barbed wire 3 exceeds 10kgf, the tensile barbed wire 3 drives the sensing main shaft 8 or the lower shell 11 to rapidly move, the speed exceeds 1 mm/min, the property of the viscoelastic inversion material body 16 is inverted, the viscosity is changed into a temporary solid body with elasticity, so that the static contact body 9 is fixed, and the probe 15 of the passive detector 2 is closed with the static contact body 9 to generate an alarm signal.

The body of viscoelastic inversion material 16 may be selected from, but is not limited to, EUDE FOAM, D3O, or PORON materials, which have impact hardening and hardness temperature-dependent properties.

The EUDE FOAM has a special impact resistance effect, when the impact speed is increased, molecular chains of an EUDEFOAM material are instantaneously self-locked, the material is hardened, and the faster the impact speed is, the faster the self-locking speed of the material is. When the impact is passed, the EUDEFOAM material molecules release self-locking and recover to a soft state, and the EUDEFOAM can reduce the impact energy by more than 70-90% according to different impact conditions.

D3O belongs to the category of "expandable foam" materials, which are impact resistant unitary materials consisting of "smart molecules" (viscose and a polymer) that can assume two mechanically similar states under different gravitational impacts: hard and soft, and its performance is characterized by the characteristics of non-Newtonian fluid.

The upper end and the lower end of the passive detector 2 are respectively fixedly connected with an upper tensile barbed wire and a lower tensile barbed wire 3, and the passive detector specifically comprises the following components: an upper wire clamp 22 is arranged at the outer end part of the sensing main shaft 8, and the tension barbed wire 3 above the upper wire clamp is fixedly connected with the sensing main shaft 8 through the upper wire clamp 22; the bottom of the lower shell 11 is provided with a stud 23, the stud 23 is provided with a lower clamp 24, and the lower tension barbed wire 3 is fixedly connected with the lower shell 11 through the lower clamp 24.

The tensile barbed wire 3 consists of a plurality of twisted sets of steel wires, which is a standard barbed wire in accordance with GB/T26941.4-2011. In the invention, the distance between two adjacent tensile barbed steel wires 3 is generally 90-200m, wherein the distance between the tensile barbed steel wires 3 below 1m from the ground is less than or equal to 100mm, the distance between the tensile barbed steel wires 3 above 1m-2m from the ground is 100mm-200mm, and the distance between the tensile barbed steel wires 3 above 2m at the inclined strut position is 200 mm. The tension barbed wire 3 is fixed by the anchor post 1 and tightened by the tensioner 6, and the fixed tension value of each tension barbed wire 3 is 35-55 kgf.

The invention discloses a passive tension fence intrusion detection system, which is triggered to alarm, and comprises the following conditions:

1. the action of climbing or destroying the tension barbed wire can make the passive detector act to trigger intrusion alarm:

because the spacing between the tensile barbed wires is tight, an intruder needs to pull the tensile barbed wires open when trying to penetrate through the fence, when the pulling force is larger than 10KGF, or the tensile barbed wires move by more than 120mm due to pulling, or the tensile barbed wires are cut off, the tension balance on the tensile barbed wires is broken, and the tensile barbed wires pull the passive detector, so that the movable contact and the fixed contact in the passive detector are closed, and the intrusion alarm is triggered.

2. Climbing terminal anchor post results in fixed tension thorn steel wire to drop, triggers intrusion alert:

the tension barbed wire is transversely fixed on the bronze flexible sheet of the anchor post, and can bear a tensile force exceeding 100kgf, but can be broken when the flexible sheet is longitudinally stressed by a force exceeding 25 kgf. If an intruder tries to tread the easily folded piece to climb and intrude, the easily folded piece is broken to cause the fixed tension barbed wire to fall off immediately, the tension barbed wire loses tension balance suddenly, and the movable contact and the fixed contact in the passive detector are closed to trigger intrusion alarm.

3. Destroy basis, enclosure and lead to supporting the slope for tension thorn steel wire is pulled, triggers intrusion alert:

the tension fence transversely fixes all the tension barbed wires through the anchor posts, in order to meet the detection tension required by the tension barbed wires, the tension borne by each tension barbed wire is 35-55kgf, and the load of the anchor posts after the tension barbed wires are tensioned is about 550 kg/m. When the support foundation (cement anchoring or wall body) of the detector column and the anchor column is damaged, the support body is loosened, at the moment, the tension barbed steel wire has the tension of 35-55kgf, the loosened support body can be pulled towards the defense area, at the moment, the tension balance of the whole tension fence is broken, the passive detector in the detector column is directly caused to act, the internal movable contact and the static contact are closed, and the intrusion alarm is triggered.

4. The lid of detector post is illegally beaten, prevents tearing open switch action, triggers to prevent tearing open the warning:

the detector column is internally provided with an anti-disassembly switch, and when the cover of the detector column is normally closed, the anti-disassembly switch inside the detector column is pressed to be closed, so that a closed dry contact signal is output. When an intruder opens the cover of the detector column to destroy, the anti-disassembly switch is released immediately, the closed contact is opened, and the anti-disassembly alarm is triggered.

5. The output signal line of detector post is cut off, triggers to prevent tearing open the warning:

2 cores in 4-core output signal wires of the detector column are connected with a movable contact and a fixed contact of all passive detectors in parallel, and the other 2 cores are connected with an anti-dismantling switch; the anti-dismantling switch is closed under normal conditions, a closed dry contact signal is output, when an output signal line is cut off, a closed signal of the anti-dismantling switch becomes an open circuit, and anti-dismantling alarm is triggered.

In the practical long-term application process, relatively slow movement can be generated between the anchor posts of the tension fence due to environmental changes such as alternate winter and summer, day-night conversion, illumination and cloudy and sunny, and the movement can cause system false alarm. However, in the passive detector of the passive tension fence intrusion detection system, due to the fact that the viscoelastic inversion material body is arranged, slow movement between anchor posts can be adapted, the whole system has a tension self-balancing adjusting mechanism due to the characteristic, and false alarms generated by expansion and contraction of tension barbed steel wires and displacement of the anchor posts caused by natural factors such as severe weather, temperature difference between day and night, four-season alternation and the like can be counteracted through the tension self-balancing adjusting mechanism, so that the constant detection sensitivity and the stable detection performance are ensured, and the false alarms generated due to environmental changes are thoroughly inhibited.

In the passive detector of the passive tension fence intrusion detection system, due to the characteristics of the viscoelastic inversion material body, the sensitivity of the passive detector can be set to be above 10KGf of the stress of the tension barbed wire to generate an alarm, so that false alarms caused by small animals passing through the tension barbed wire and touching the tension barbed wire can be eliminated, and the false alarm rate is reduced.

Since the system as a whole is of a pure mechanical structure, particularly a passive detector, and does not contain any electronic components, the Mean Time Between Failure (MTBF) of the product is designed to be 2500 ten thousand hours. Generally, the design value of the overall Mean Time Between Failure (MTBF) of a system with the height of 2.5 meters, 24 tensile steel wires and a defense area of 60 meters is more than or equal to 76 ten thousand hours.

The passive tension fence intrusion detection system has the following characteristics:

1. the passive detector has no electronic element and does not need to be powered;

2. sensitivity: fixation, not influenced by climatic conditions;

3. trigger force: triggering an alarm when the stress is 10-40 kgf or more;

4. false alarm rate: at most 1 false alarm every 1 kilometer and every 3 months;

5. mean time to failure of the detector: 2500 ten thousand hours;

6. and (4) alarm output: 1 normally open dry contact

7. Anti-dismantling output: 1 normally closed dry contact

8. Temperature range: -40 ℃ to 72 ℃

9. Relative humidity: no condensation at maximum 95%;

10. and (3) climate adaptation: is not affected by wind, rain, ice, hail, snow, dust, temperature change, ultraviolet irradiation and the like. The ice and snow cover can be normally used in desert areas, strong storms, tropical climates and ice and snow covered areas below zero without excessive maintenance.

Claims

1. A passive tension fence intrusion detection system is characterized by comprising a passive detector, a tension barbed wire and a signal wire;

2. The passive tension fence intrusion detection system of claim 1, further comprising: the device comprises an anchor post, a detector post, a spiral post and a tensioner, wherein the anchor post is arranged at two ends of a defense area, and two ends of a plurality of tension barbed steel wires are fixed on a bronze easy-to-fold piece of the anchor post through the tensioner; a plurality of spiral columns are arranged between the two anchor columns at intervals and in parallel, and the middle parts of the tensile barbed wires are supported and positioned on the spiral columns; and the central positions of the two anchor posts are provided with detector posts, and the passive detectors are arranged in the detector posts.

3. The passive tension fence intrusion detection system of claim 1 wherein the passive detector comprises an upper housing and a lower housing, the upper housing being made of an elastomeric material and the lower housing being made of a rigid material, the sensing spindle being secured to the upper housing, the elastomeric material of the upper housing not impeding the relative movement of the sensing spindle.

4. The passive tension fence intrusion detection system of claim 3, wherein the upper housing comprises an upper main body and a downwardly extending annular wall, the lower housing is of a concave structure, a fixing unit is disposed between an outer wall of the lower housing and an inner wall of the annular wall, and the upper housing and the lower housing are fixed by the fixing unit after the lower housing is inserted upwards into the annular wall.

5. The passive tension fence intrusion detection system of claim 4 wherein the sensing spindle is fixed to the upper body, the lower end of the sensing spindle being configured as a small diameter probe; the viscoelastic inverter material body is arranged at the bottom of the concave structure of the lower shell, the static contact body comprises a conical base and a cup body, the conical base is wrapped by the viscoelastic inverter material body, the probe is inserted into the cup body, and a safety gap is formed between the probe and the inner wall of the cup body.

6. The passive tension fence intrusion detection system of claim 5 wherein when tension between the tension barbed wires is unbalanced, the viscoelastic-to-inverse material body is forced to become a temporary solid body to fix the position of the conical base relatively, the upper housing is deformed, and when the sensing spindle moves relatively, the probe is triggered by the inner wall of the cup body, so that the signal wire is closed to generate an alarm signal.

7. The passive tension fence intrusion detection system of claim 5, wherein a plurality of said passive detectors are connected in parallel to said signal lines by lead wires, respectively; the upper portion of sensing main shaft through first lead wire with the signal line intercommunication, the cup through the second lead wire with the signal line intercommunication, be provided with the lead wire groove between the outer wall of lower casing and the inner wall of rampart, the second lead wire is drawn forth through the lead wire groove outwards.

8. The passive tension fence intrusion detection system of claim 1 wherein the outer end of the sensing spindle is provided with an upper clamp, the tension barbed wire being fixedly connected to the sensing spindle by the upper clamp.

9. The passive tension fence intrusion detection system of claim 3, wherein the bottom of the lower housing is provided with a stud, the stud is provided with a lower clamp, and the tension barbed wire is fixedly connected with the lower housing through the lower clamp.

10. The passive tension fence intrusion detection system of claim 1, wherein the distance between two adjacent tension barbed wires is 90-200m, wherein the distance between the tension barbed wires below 1m from the ground is less than or equal to 100mm, the distance between the tension barbed wires 1m-2m from the ground is 100mm-200mm, and the distance between the tension barbed wires at the bracing position above 2m is 200 mm.

11. The passive tension fence intrusion detection system of claim 2 wherein the tension barbed wires are secured by the anchor posts, tensioned by tensioners, each tension barbed wire securing a tension value of 35-55 kgf.

12. The passive tension fence intrusion detection system of claim 1, wherein the viscoelastic-to-elastic inverter material body maintains fluidity and plasticity when the tension barbed wire moves horizontally at a speed of less than 1 mm/min along the fence direction, the sensing spindle and the static contact body synchronously generate deformation displacement, and the sensing spindle and the static contact body do not trigger to generate closure and do not generate an alarm signal; when the external force applied by an intruder by the tension barbed wire exceeds 10kgf, the tension barbed wire drives a part of the passive detector to rapidly move, the speed exceeds 1 mm/min, the property of the viscoelastic inversion material body is inverted and changed into a temporary solid body, so that the static contact body is fixed, the sensing main shaft and the static contact body are closed, and an alarm signal is generated.