JP6835406B2 - Displacement sensor and displacement measuring device - Google Patents

Description

The present invention relates to a displacement sensor and a displacement measuring device, for example, a displacement sensor and a displacement measuring device used for measuring a displacement amount of a bridge or the like.

In recent years, aging infrastructure such as road and railroad bridges has become a social problem, and a large amount of money is spent on regular inspections to confirm the soundness of these. In addition, when an earthquake occurs, it is necessary for the investigator to go to check the condition of the bridges, etc. in order to check the soundness of the bridges, etc., but it is difficult to check all the bridges, etc. at the same time. For this reason, there is a demand for a sensor that can constantly monitor the state of infrastructure remotely and can measure the presence or absence of a displacement exceeding the structural design value of a bridge or the like due to an earthquake.

For example, it is conceivable to measure the amount of displacement of a bridge or the like using a flat antenna. However, when a planar antenna is used, when measuring the amount of displacement in the vertical direction (Z-axis), the measurement target is unstable and the measurement target is unstable, causing blurring or tilting in the X-axis direction and the Y-axis direction. It becomes impossible to measure the amount of displacement accurately.

Further, Patent Document 1 discloses a displacement sensor that detects the displacement amount of an object by using a coil, a conical magnetic probe, an inductance meter, and a displacement amount conversion unit. In the displacement sensor of Patent Document 1, when the magnetic probe moves in the air core portion of the coil, the inductance of the coil changes. Then, the inductance meter detects the change in the inductance of the coil, and the displacement amount conversion unit converts the detected value into the displacement amount.

However, in the displacement sensor of Patent Document 1, friction between the coil and the magnetic probe may occur, so that there is a problem in the durability of the coil.

Patent Document 2 discloses an example of a sensor in which the coil and the shaft do not rub against each other. In the position sensor of Patent Document 2, in the sensor coil portion, a space for inserting the shaft is provided in the center of the resin case, a coil storage portion is formed so as to sandwich this space, and the coil is stored in the coil storage portion. doing.

Japanese Unexamined Patent Publication No. 2003-139562 Japanese Unexamined Patent Publication No. 2000-161985

In the sensor coil portion of Patent Document 2, the material is different between the coil and the portion other than the coil. Therefore, the coefficient of thermal expansion differs between the coil in the sensor coil portion and the portion other than the coil. As a result, when the position sensor of Patent Document 2 is used in an environment where the temperature change is large, there is a problem that the coil may be broken due to the difference in the coefficient of thermal expansion between the coil of the sensor coil portion and the portion other than the coil. there were.

The present invention has been made to solve such a problem, and provides a displacement sensor and a displacement measuring device capable of preventing a decrease in measurement accuracy and a disconnection of a coil due to a temperature change. The purpose is to do.

The displacement sensor according to the first aspect of the present invention is a coil base which is hollow and has a shaft cap which is a portion in contact with an object to be measured, a metal shaft connected to the shaft cap, and the metal shaft is inserted. By measuring the changes in the inductance and resistance of the coil as the metal shaft moves in the coil base with the coil wound around the outer peripheral surface of the coil base and the current flowing through the coil. A displacement amount measuring unit for measuring the displacement amount of the metal shaft is provided, and a spiral auxiliary groove is provided on the outer peripheral surface of the coil base, and the coil is wound around the auxiliary groove.

The displacement measuring device according to the second aspect of the present invention includes a plurality of displacement sensors that measure the amount of displacement of the object to be measured in different directions, and a slave station that receives the measurement results of the amount of displacement in the plurality of displacement sensors. Each of the plurality of displacement sensors is hollow, has a shaft cap which is a portion in contact with the object to be measured, a metal shaft connected to the shaft cap, and a coil into which the metal shaft is inserted. Measuring changes in the inductance and resistance of the coil due to the movement of the metal shaft in the coil base with a base, a coil wound around the outer peripheral surface of the coil base, and a current flowing through the coil. A displacement amount measuring unit for measuring the displacement amount of the metal shaft, a first connector for receiving the measurement result of the displacement amount of the metal shaft in another displacement sensor, and the metal shaft in the displacement amount measuring unit. A second connector for transmitting at least one of the measurement result of the displacement amount of the metal shaft and the measurement result of the displacement amount of the metal shaft in the other displacement sensor, and the reception of the measurement result of the displacement amount via the first connector. A transmission / reception unit for transmitting at least one of the measurement results of the displacement amount via the second connector is provided, and a spiral auxiliary groove is provided on the outer peripheral surface of the coil base, and the coil is provided with the auxiliary groove. The plurality of displacement sensors and the slave station are connected in a string.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a displacement sensor and a displacement measuring device capable of preventing a decrease in measurement accuracy and preventing disconnection of a coil due to a temperature change.

It is a figure which shows the structural example of the displacement sensor which concerns on Embodiment 1 of this invention. It is a figure which shows that the metal shaft of FIG. 1 moves in the coil base in conjunction with the movement of the object to be measured. It is a figure which shows that the metal shaft of FIG. 1 moves in the coil base in conjunction with the movement of the object to be measured. It is a figure which shows an example of the state in which the coil of FIG. 1 is wound in an auxiliary groove. It is a figure which shows an example of the state which the coil in the displacement sensor which concerns on Embodiment 2 of this invention is wound around a coil base. It is a figure which shows the structure which the shaft cap, the metal shaft, and the slider in the displacement sensor which concerns on Embodiment 3 of this invention are connected. It is a side sectional view of the shaft cap, the metal shaft, the slider, and the coil base in the displacement sensor which concerns on Embodiment 3 of this invention. It is a figure which shows the structural example of the displacement sensor which concerns on Embodiment 4 of this invention. It is a figure which shows the structural example of the displacement sensor which concerns on Embodiment 5 of this invention. It is a block diagram which shows the structural example of the displacement measuring apparatus which concerns on Embodiment 5 of this invention. It is a block diagram which shows the structural example of the network sensor system which concerns on Embodiment 5 of this invention. It is a figure which shows the example of the cover which stores the displacement sensor which concerns on embodiment of this invention. It is a figure which shows the example of the cover which stores the displacement sensor which concerns on embodiment of this invention. It is a side sectional view which shows the modification of the shaft cap and the metal shaft in the displacement sensor which concerns on embodiment of this invention. FIG. 5 is a side sectional view showing an example in which a shaft cap or a second case in the displacement sensor according to the embodiment of the present invention includes a first air hole. FIG. 5 is a side sectional view showing an example in which a shaft cap or a second case in the displacement sensor according to the embodiment of the present invention includes a first air hole. FIG. 5 is a side sectional view showing an example in which a shaft cap or a second case in the displacement sensor according to the embodiment of the present invention includes a first air hole.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each drawing, the same or corresponding elements are designated by the same reference numerals, and duplicate explanations are omitted as necessary for the sake of clarity of explanation.

Embodiment 1
First, a configuration example of the displacement sensor 100 according to the first embodiment of the present invention will be described with reference to FIG. The displacement sensor 100 according to the first embodiment includes a shaft cap 11, a metal shaft 12, a coil base 21, a coil 22, and a displacement amount measuring unit 23.

The shaft cap 11 is a portion that comes into contact with the object to be measured 600. The material used for the shaft cap 11 is, for example, resin.

The metal shaft 12 is used in a state of being connected to the shaft cap 11. The metal shaft 12 moves in a state where the object to be measured 600 and the shaft cap 11 are in contact with each other, so that the metal shaft 12 is linked to the movement of the object to be measured 600. The material used for the metal shaft 12 is, for example, stainless steel. Further, the metal shaft 12 may be hollow. By making the metal shaft 12 hollow, a magnetic field that passes through the inside of the metal shaft 12 in the longitudinal direction can be formed.

The coil base 21 is hollow, and the metal shaft 12 is inserted into the coil base 21. That is, the metal shaft 12 moves in the coil base 21 in conjunction with the movement of the object to be measured 600. The movement of the metal shaft 12 in the coil base 21 in conjunction with the movement of the object to be measured 600 means that the displacement sensor 100 transitions from, for example, the state of FIG. 2A to the state of FIG. 2B. The material used for the coil base 21 is, for example, resin.

The coil 22 is wound around the outer peripheral surface of the coil base 21. Specifically, a spiral auxiliary groove 24 is provided on the outer peripheral surface of the coil base 21, and the coil 22 is wound around the auxiliary groove 24. The material used for the coil 22 is, for example, copper.

The displacement amount measuring unit 23 measures changes in the inductance and resistance of the coil 22 as the metal shaft 12 moves in the coil base 21 while a current is flowing through the coil 22. As a result, the displacement amount measuring unit 23 measures the displacement amount of the metal shaft 12.

Subsequently, the winding of the coil 22 around the auxiliary groove 24 will be described with reference to FIG. In the example of FIG. 3, a gap (gap) is provided between the coil base 21 and the coil 22. Here, it is assumed that the example of FIG. 3 shows a state in a temperature condition of 20 ° C.

The reason for providing a gap between the coil base 21 and the coil 22 will be described. When the coil base 21 is made of, for example, a polycarbonate resin, the coefficient of thermal expansion of the coil base 21 is 70 to 80. When the coil 22 is made of copper, for example, the coefficient of thermal expansion of the coil 22 is 16.6. In such a case, the coefficient of thermal expansion associated with the increase in temperature of the coil base 21 is larger than that of the coil 22. Therefore, for example, in a temperature condition of 20 ° C., when there is no gap between the coil base 21 and the coil 22, the coil 22 is extended by the swelling due to thermal expansion of the coil base 21 when the temperature rises. There is a possibility of disconnection. By providing a gap between the coil base 21 and the coil 22, such disconnection of the coil 22 can be prevented.

The amount of change in the coil base 21 due to thermal expansion can be calculated by α × ΔT × 2r. Here, α is the coefficient of thermal expansion (unit [× 10 ^-6 / ° C]), ΔT is the amount of temperature change (unit [° C]), and r is the radius of the coil base 21 (unit [mm]). is there. For example, when the diameter of the coil base 21 is 26 mm and there is a temperature rise of 50 ° C., the diameter of the coil base 21 becomes 0.091 to 0.104 mm larger. Therefore, when the diameter of the coil base 21 is 26 mm, a gap of 0.104 mm or more may be provided between the coil base 21 and the coil 22.

If a gap is provided between the coil base 21 and the coil 22 without providing the auxiliary groove 24, the winding of the coil 22 may be displaced in the longitudinal direction of the coil base 21. The misalignment of the winding of the coil 22 reduces the measurement accuracy of the displacement amount of the metal shaft 12. Therefore, if a gap is provided between the coil base 21 and the coil 22 without providing the auxiliary groove 24, the measurement accuracy of the displacement amount of the metal shaft 12 can be lowered.

On the other hand, by providing the auxiliary groove 24, the wall surface of the auxiliary groove 24 suppresses the misalignment of the winding of the coil 22. Therefore, by providing the auxiliary groove 24, even if a gap is provided between the coil base 21 and the coil 22, the winding of the coil 22 is prevented from being displaced in the longitudinal direction of the coil base 21. can do.

That is, by providing the auxiliary groove 24 and winding the coil 22 around the auxiliary groove 24, it is possible to prevent a decrease in the measurement accuracy of the displacement amount of the metal shaft 12 and prevent the coil 22 from being disconnected due to a temperature change.

The auxiliary groove 24 is provided in a V shape, for example, as in the example of FIG. 3, but the shape of the auxiliary groove 24 is not limited to the V shape. For example, the auxiliary groove 24 may be U-shaped or the like. When the auxiliary groove 24 is V-shaped, the force of the coil base 21 on the coil 22 during expansion is dispersed as compared with the case where the auxiliary groove 24 is U-shaped, so that the disconnection of the coil 22 can be further prevented. it can.

As described above, the displacement sensor 100 according to the first embodiment of the present invention has a configuration in which a spiral auxiliary groove 24 is provided on the outer peripheral surface of the coil base 21. Further, in the displacement sensor 100, the coil 22 is configured to be wound around the auxiliary groove 24. As a result, the displacement sensor 100 can prevent a decrease in the measurement accuracy of the displacement amount of the metal shaft 12 and prevent a disconnection of the coil 22 due to a temperature change.

Embodiment 2
Subsequently, a configuration example of the displacement sensor 200 according to the second embodiment of the present invention will be described. The displacement sensor 200 according to the second embodiment includes a shaft cap 11, a metal shaft 12, a coil base 21, a coil 22, a displacement amount measuring unit 23, and a lid 25. The configuration of the displacement sensor 200 other than the lid 25 is the same as the configuration of the displacement sensor 100 of the first embodiment, and the description thereof will be omitted. The material used for the lid 25 is, for example, polyimide tape.

FIG. 4 is a diagram showing an example of a state in which the coil 22 of the displacement sensor 200 is wound around the coil base 21. As shown in FIG. 4, the displacement sensor 200 has a configuration in which the auxiliary groove 24 is covered with the lid 25. As a result, in the displacement sensor 200, the coil 22 can be kept in the space formed by the auxiliary groove 24 and the lid 25. That is, the misalignment of the winding of the coil 22 can be further suppressed.

As described above, the displacement sensor 200 according to the second embodiment of the present invention has a configuration in which the auxiliary groove 24 is covered with the lid 25. As a result, the displacement sensor 200 can further suppress the misalignment of the winding of the coil 22.

Embodiment 3
Subsequently, a configuration example of the displacement sensor 300 according to the third embodiment of the present invention will be described. The displacement sensor 300 according to the third embodiment includes a shaft cap 11, a metal shaft 12, a slider 13, a coil base 21, a coil 22, and a displacement amount measuring unit 23. The configuration of the displacement sensor 300 other than the slider 13 is the same as the configuration of the displacement sensor 100 of the first embodiment, and the description thereof will be omitted. The displacement sensor 300 may further include a lid 25.

FIG. 5 is a diagram showing a configuration in which the shaft cap 11, the metal shaft 12, and the slider 13 are connected. The slider 13 has a columnar shape. The material used for the slider 13 is preferably a material having good slidability, such as polyacetal resin. Further, the slider 13 may be hollow. When the slider 13 is hollow, the connection between the metal shaft 12 and the slider 13 is performed, for example, by press-fitting the metal shaft 12 into the hollow of the slider 13.

Subsequently, a state in which the outer peripheral surface of the slider 13 is in close contact with the inner peripheral surface of the coil base 21 will be described with reference to FIG. FIG. 6 is a side sectional view of the shaft cap 11, the metal shaft 12, the slider 13, and the coil base 21. In the example of FIG. 6, the metal shaft 12 and the slider 13 are hollow.

The hollow portion of the coil base 21 is columnar. Further, the circumferential dimension of the outer peripheral side surface of the slider 13 is the same as the circumferential dimension of the inner peripheral side surface of the coil base 21. That is, the outer peripheral surface of the slider 13 is in close contact with the inner peripheral surface of the coil base 21. Further, by using a material having good slidability as the material of the slider 13, the slider 13 can move in the longitudinal direction of the coil base 21. That is, the metal shaft 12 can move in the longitudinal direction of the coil base 21 while the outer peripheral surface of the slider 13 is in close contact with the inner peripheral surface of the coil base 21.

Since the outer peripheral surface of the slider 13 is in close contact with the inner peripheral surface of the coil base 21, the metal shaft 12 moves only in the longitudinal direction of the coil base 21. Therefore, in the displacement sensor 300, even if the object to be measured 600 moves in a direction other than the measurement direction (longitudinal direction of the coil base 21), the metal shaft 12 is prevented from moving in a direction other than the longitudinal direction of the coil base 21. be able to. That is, the displacement sensor 300 can accurately measure the amount of displacement of the object to be measured 600 in the measurement direction.

As described above, in the displacement sensor 300 according to the third embodiment of the present invention, the slider 13 is connected to the metal shaft 12. Further, in the displacement sensor 300, the outer peripheral surface of the slider 13 is in close contact with the inner peripheral surface of the coil base 21. Further, the displacement sensor 300 is configured to use a material having good slidability as the material of the slider 13. As a result, in the displacement sensor 300, the metal shaft 12 can be prevented from moving except in the longitudinal direction of the coil base 21. That is, the displacement sensor 300 can accurately measure the amount of displacement of the object to be measured 600 in the measurement direction.

Embodiment 4
Subsequently, a configuration example of the displacement sensor 400 according to the fourth embodiment of the present invention will be described with reference to FIG. 7. The displacement sensor 400 according to the fourth embodiment of the present invention includes a shaft cap 11, a metal shaft 12, a coil base 21, a coil 22, a displacement amount measuring unit 23, a first case 26, and a second case. It is provided with a case 27. The configuration of the displacement sensor 400 other than the first case 26 and the second case 27 is the same as the configuration of the displacement sensor 100 of the first embodiment, and the description thereof will be omitted. The displacement sensor 400 may further include a lid 25. Further, the displacement sensor 400 may further include a slider 13.

The first case 26 is a case for storing the coil base 21 in a state where the coil 22 is wound. The material used in the first case 26 is a metal such as aluminum. By storing the coil base 21 in which the coil 22 is wound in the first case 26, it is possible to prevent the influence of external noise in measuring the displacement amount of the metal shaft 12.

A magnetic sheet (not shown) may be arranged between the first case 26 and the coil base 21. The type of magnetic material used for the magnetic material sheet is, for example, ferrite. By arranging the magnetic material sheet between the first case 26 and the coil base 21, it is possible to reduce the influence of the metal of the first case 26 on the measurement of the displacement amount of the metal shaft 12.

The second case 27 is a case for storing the displacement amount measuring unit 23. The material used in the second case 27 is, for example, resin. By storing the displacement amount measuring unit 23 in the second case 27, it is possible to prevent water from entering the displacement amount measuring unit 23 due to rainfall or the like.

As described above, the displacement sensor 400 according to the fourth embodiment of the present invention includes a first case 26 for storing the coil base 21 in which the coil 22 is wound. As a result, the displacement sensor 400 can prevent the influence of external noise in measuring the displacement amount of the metal shaft 12.

Further, the displacement sensor 400 is configured to include a second case 27 for storing the displacement amount measuring unit 23. As a result, the displacement sensor 400 can prevent water from entering the displacement amount measuring unit 23 due to rainfall or the like.

Embodiment 5
Subsequently, a configuration example of the displacement sensor 500 according to the fifth embodiment of the present invention will be described with reference to FIG. The displacement sensor 500 according to the fifth embodiment of the present invention includes a shaft cap 11, a metal shaft 12, a coil base 21, a coil 22, a displacement amount measuring unit 23, a first connector 28, and a second connector. It includes a connector 29 and a transmission / reception unit 30. The configuration of the displacement sensor 500 other than the first connector 28, the second connector 29, and the transmission / reception unit 30 is the same as the configuration of the displacement sensor 100 of the first embodiment, and the description thereof will be omitted. The displacement sensor 500 may further include a lid 25. Further, the displacement sensor 500 may further include a slider 13. Further, the displacement sensor 500 may further include a first case 26 and a second case 27.

The first connector 28 is a connector for receiving the measurement result of the displacement amount of the metal shaft in another displacement sensor.

The second connector 29 is a connector for transmitting at least one of the measurement result of the displacement amount of the metal shaft 12 by the displacement amount measuring unit 23 and the measurement result of the displacement amount of the metal shaft by another displacement sensor.

The transmission / reception unit 30 is a transmission / reception unit that receives at least one of the measurement result of the displacement amount via the first connector 28 and the transmission of the measurement result of the displacement amount via the second connector 29.

Specifically, the transmission / reception unit 30 receives the measurement result of the displacement amount of the metal shaft 12 in the displacement amount measurement unit 23 from the displacement amount measurement unit 23. Further, when the transmission / reception unit 30 receives the measurement result of the displacement amount of the metal shaft in another displacement sensor via the first connector 28, the transmission / reception unit 30 and the measurement result of the displacement amount of the metal shaft 12 in the displacement amount measurement unit 23 , The measurement result of the displacement amount of the metal shaft in another displacement sensor is transmitted via the second connector 29. Further, when the transmission / reception unit 30 does not receive the measurement result of the displacement amount of the metal shaft in the other displacement sensor via the first connector 28, only the measurement result of the displacement amount of the metal shaft 12 in the displacement amount measurement unit 23 Is transmitted via the second connector 29.

Subsequently, a configuration example of the displacement measuring device 1 according to the fifth embodiment will be described with reference to the block diagram of FIG. The displacement measuring device 1 includes a first displacement sensor 500A, a second displacement sensor 500B, a third displacement sensor 500C, and a slave station 700. Further, the first displacement sensor 500A, the second displacement sensor 500B, the third displacement sensor 500C, and the slave station 700 are connected in a string.

The first displacement sensor 500A, the second displacement sensor 500B, and the third displacement sensor 500C are three displacement sensors that measure the amount of displacement of the object to be measured 600 in different directions. In the example of FIG. 9, the number of displacement sensors is three, but the number of displacement sensors may be a plurality, that is, any number as long as it is two or more. In this example, the first displacement sensor 500A measures the amount of displacement of the object to be measured 600 in the X direction, the second displacement sensor 500B measures the amount of displacement of the object to be measured 600 in the Y direction, and the third displacement. A case where the sensor 500C measures the displacement amount of the object to be measured 600 in the Z direction will be described.

Further, the first displacement sensor 500A, the second displacement sensor 500B, and the third displacement sensor 500C are each composed of the displacement sensor 500 described with reference to FIG. The connectors indicated by the reference numerals 28A, 28B, and 28C in FIG. 9 are the first connectors in the first displacement sensor 500A, the second displacement sensor 500B, and the third displacement sensor 500C, respectively. Further, the connectors indicated by the reference numerals 29A, 29B, and 29C in FIG. 9 are the second connectors in the first displacement sensor 500A, the second displacement sensor 500B, and the third displacement sensor 500C, respectively.

The first displacement sensor 500A measures the displacement amount of the object to be measured 600 in the X direction by the displacement amount measuring unit 23A provided by the first displacement sensor 500A. Further, the displacement amount measuring unit 23A outputs the measurement result of the displacement amount of the object to be measured 600 in the X direction to the transmission / reception unit 30A. Then, the transmission / reception unit 30A transmits the measurement result of the displacement amount of the object to be measured 600 in the X direction to the second displacement sensor 500B via the second connector 29A.

The second displacement sensor 500B measures the displacement amount of the object to be measured 600 in the Y direction by the displacement amount measuring unit 23B provided by the second displacement sensor 500B. Further, the displacement amount measuring unit 23B outputs the measurement result of the displacement amount of the object to be measured 600 in the Y direction to the transmission / reception unit 30B. Further, the transmission / reception unit 30B receives the measurement result of the displacement amount of the object to be measured 600 in the X direction via the first connector 28B. Then, the transmission / reception unit 30B transmits the measurement result of the displacement amount in the X direction and the measurement result of the displacement amount in the Y direction of the object to be measured 600 to the third displacement sensor 500C via the second connector 29B.

The third displacement sensor 500C measures the displacement amount of the object to be measured 600 in the Z direction by the displacement amount measuring unit 23C provided by the third displacement sensor 500C. Further, the displacement amount measuring unit 23C outputs the measurement result of the displacement amount of the object to be measured 600 in the Z direction to the transmission / reception unit 30C. Further, the transmission / reception unit 30C receives the measurement result of the displacement amount in the X direction and the measurement result of the displacement amount in the Y direction of the object to be measured 600 via the first connector 28C. Then, the transmission / reception unit 30C transfers the measurement result of the displacement amount in the X direction, the measurement result of the displacement amount in the Y direction, and the measurement result of the displacement amount in the Z direction of the object to be measured 600 via the second connector 29C. Send to station 700.

The slave station 700 receives the measurement result of the displacement amount in the X direction of the object to be measured 600, the measurement result of the displacement amount in the Y direction, and the measurement result of the displacement amount in the Z direction.

As described above, in the displacement measuring device 1 according to the fifth embodiment, the first displacement sensor 500A, the second displacement sensor 500B, the third displacement sensor 500C, and the slave station 700 are connected in a string. It is configured to be connected. Further, in the displacement measuring device 1, the first displacement sensor 500A measures the amount of displacement of the object to be measured 600 in the X direction, and the second displacement sensor 500B measures the amount of displacement of the object to be measured 600 in the Y direction. The third displacement sensor 500C is configured to measure the amount of displacement of the object to be measured 600 in the Z direction. As a result, in the displacement measuring device 1, the slave station 700 receives the measurement result of the displacement amount in the X direction, the measurement result of the displacement amount in the Y direction, and the measurement result of the displacement amount in the Z direction of the object to be measured 600. Can be done.

Subsequently, the network sensor system 10 according to the fifth embodiment will be described with reference to the block diagram of FIG. The network sensor system 10 includes a displacement measuring device 1, a master station 2, a network 3, and a server 4.

The displacement measuring device 1 transmits the measurement result of the displacement amount in the X direction of the object to be measured 600, the measurement result of the displacement amount in the Y direction, and the measurement result of the displacement amount in the Z direction to the master station 2.

The master station 2 is, for example, an edge computer. The master station 2 transmits the measurement result of the displacement amount in the X direction, the measurement result of the displacement amount in the Y direction, and the measurement result of the displacement amount in the Z direction of the object to be measured 600 to the server 4 via the network 3. The network 3 is, for example, a network of a third-generation mobile phone, but is not limited to this.

As described above, in the network sensor system 10 according to the fifth embodiment, the displacement measuring device 1 measures the displacement amount of the object 600 in the X direction, the displacement amount in the Y direction, and the Z direction. The displacement measurement result is transmitted to the server 4 via the master station 2 and the network 3. As a result, in the network sensor system 10, the displacement measuring device 1 transmits the measurement result of the displacement amount in the X direction, the measurement result of the displacement amount in the Y direction, and the measurement result of the displacement amount in the Z direction of the object to be measured 600 to the server. Can be provided to 4. That is, when an infrastructure such as a bridge is used as the object to be measured 600, the state of the infrastructure can be constantly monitored remotely.

Although the present invention has been described above with reference to the embodiments, the present invention is not limited to the above embodiments. Various changes that can be understood by those skilled in the art can be made within the scope of the invention in the configuration and details of the invention of the present application.

For example, the displacement sensors 100 to 500 may be housed in the cover 40 shown in FIGS. 11A and 11B. By being stored in the cover 40, the displacement sensor 100 to the displacement sensor 500 can have a dustproof effect and a waterproof effect. The cover 40 has a bellows structure, and can transition between the state shown in FIG. 11A and the state shown in FIG. 11B according to the displacement of the object to be measured 600 in the measurement direction.

Further, when the displacement sensor is housed in the cover 40, the shaft cap 11 and the metal shaft 12 may be replaced with the shaft cap 11A and the metal shaft 12A shown in FIG. The shaft cap 11A includes a vent 14 and a first air hole 15. Further, the metal shaft 12A is hollow and includes a second air hole 16.

The vent 14 allows air to pass through but does not allow water to pass through. In the example of FIG. 12, the first air hole 15 is provided at a position adjacent to the vent 14. Further, the second air hole 16 is provided in the vicinity of the connecting portion of the metal shaft 12A with the slider 13. The shaft cap 11A and the metal shaft 12A form a path through which air passes, which is composed of a second air hole 16, a hollow portion of the metal shaft 12A, a vent 14, and a first air hole 15. In addition, water is not allowed to pass through the vent 14. As a result, in the displacement sensor provided with the shaft cap 11A and the metal shaft 12A, when the bellows of the cover 40 contracts or expands, air can be taken in and out by this path. Further, in the displacement sensor provided with the shaft cap 11A and the metal shaft 12A, water can be prevented from passing through this path.

Further, when the displacement sensor is housed in the cover 40, the shaft cap 11 or the second case 27 may be provided with the first air hole. An example in which the shaft cap 11 or the second case 27 includes the first air hole is shown in FIGS. 13A to 13C. Assuming an environment in which the displacement sensor is installed, it is preferable to arrange the first air hole so as to be in the ground direction (Z-axis minus direction).

In the example of FIG. 13A, the shaft cap 11B has a configuration including a first air hole 15B. Further, the first air hole 15B is arranged so as to face the ground. Further, the metal shaft 12A is hollow and includes a second air hole 16. The shaft cap 11B and the metal shaft 12A form a path through which air passes, which is composed of a second air hole 16, a hollow portion of the metal shaft 12A, and a first air hole 15B. Further, since the first air hole 15B is arranged so as to face the ground, it is difficult for water due to rainfall to enter. As a result, in the displacement sensor provided with the shaft cap 11A and the metal shaft 12B, when the bellows of the cover 40 contracts or expands, air can be taken in and out by this path. Further, in the displacement sensor provided with the shaft cap 11A and the metal shaft 12B, it is possible to make it difficult for water to pass through this path. Assuming an environment in which the displacement sensor is installed, the arrangement of the first air hole 15B may be the position shown in FIG. 13B.

In the example of FIG. 13C, the second case 27B is configured to include the first air hole 31. Further, the first air hole 31 is arranged so as to face the ground. Further, the metal shaft 12A is hollow and includes a second air hole 16. In the metal shaft 12A and the second case 27B, a path through which air passes is formed by the second air hole 16, the hollow portion of the metal shaft 12A, the hollow portion of the coil base 21, and the first air hole 31. .. Further, since the first air hole 31 is arranged so as to face the ground, it is difficult for water due to rainfall to enter. As a result, in the displacement sensor provided with the metal shaft 12A and the second case 27B, when the bellows of the cover 40 contracts or expands, air can be taken in and out by this path. Further, in the displacement sensor provided with the metal shaft 12A and the second case 27B, it is possible to make it difficult for water to pass through this path.

In addition, a configuration may be configured in which both the first air hole 15B and the first air hole 31 are provided, and a lid is further provided to cover the first air hole 15B and the first air hole 31. In this case, by covering one of the unused air holes of the first air hole 15B and the first air hole 31 with a lid, the same effect as that of the examples of FIGS. 13A to 13C can be obtained.

In addition, some or all of the above embodiments may be described as in the following appendix, but are not limited to the following.

(Appendix 1)
The shaft cap, which is the part that comes into contact with the object to be measured,
With the metal shaft connected to the shaft cap,
A coil base that is hollow and into which the metal shaft is inserted,
The coil wound around the outer peripheral surface of the coil base and
With a displacement amount measuring unit that measures the displacement amount of the metal shaft by measuring changes in the inductance and resistance of the coil as the metal shaft moves in the coil base while a current is flowing through the coil. With,
A spiral auxiliary groove is provided on the outer peripheral surface of the coil base.
The coil is wound in the auxiliary groove,
Displacement sensor.

(Appendix 2)
The displacement sensor according to Appendix 1, wherein the auxiliary groove is provided in a V shape.

(Appendix 3)
The displacement sensor according to Appendix 1 or 2, further comprising a lid that covers the auxiliary groove.

(Appendix 4)
The displacement sensor according to any one of Appendix 1 to 3, wherein the metal shaft is hollow.

(Appendix 5)
Further provided with a slider connected to the metal shaft
The material of the slider is a material having good slidability.
The outer peripheral surface of the slider is in close contact with the inner peripheral surface of the coil base.
The displacement sensor according to any one of Appendix 1 to 4.

(Appendix 6)
Further provided with a first case for accommodating the coil base with the coil wound.
The first case is a metal case,
The displacement sensor according to any one of Appendix 1 to 5.

(Appendix 7)
With a magnetic sheet,
The magnetic sheet is arranged between the first case and the coil base.
The displacement sensor according to Appendix 6.

(Appendix 8)
The displacement sensor according to any one of Appendix 1 to 7, further comprising a second case for storing the displacement amount measuring unit.

(Appendix 9)
With more covers
The displacement sensor is housed in the cover.
The displacement sensor according to Appendix 1.

(Appendix 10)
The displacement sensor according to Appendix 9, wherein the cover has a bellows structure.

(Appendix 11)
The shaft cap comprises a vent and a first air hole.
The metal shaft is hollow and comprises a second air hole.
The displacement sensor according to Appendix 10.

(Appendix 12)
A second case for storing the displacement amount measuring unit is further provided.
The shaft cap or the second case comprises a first air hole.
The metal shaft is hollow and comprises a second air hole.
The displacement sensor according to Appendix 10.

(Appendix 13)
A second case for storing the displacement amount measuring unit and
Further equipped with a lid to cover the first air hole,
The shaft cap and the second case include the first air hole.
The metal shaft is hollow and comprises a second air hole.
The displacement sensor according to Appendix 10.

(Appendix 14)
Multiple displacement sensors that measure the amount of displacement in different directions on the object to be measured,
A slave station that receives the measurement result of the displacement amount in the plurality of displacement sensors is provided.
Each of the plurality of displacement sensors
The shaft cap, which is the part that comes into contact with the object to be measured,
With the metal shaft connected to the shaft cap,
A coil base that is hollow and into which the metal shaft is inserted,
The coil wound around the outer peripheral surface of the coil base and
With a displacement amount measuring unit that measures the displacement amount of the metal shaft by measuring changes in the inductance and resistance of the coil as the metal shaft moves in the coil base while a current is flowing through the coil. ,
A first connector for receiving the measurement result of the displacement amount of the metal shaft in another displacement sensor, and
A second connector for transmitting at least one of the measurement result of the displacement amount of the metal shaft in the displacement amount measuring unit and the measurement result of the displacement amount of the metal shaft in the other displacement sensor.
A transmission / reception unit for receiving at least one of a displacement measurement result via the first connector and a displacement measurement result transmission via the second connector is provided.
A spiral auxiliary groove is provided on the outer peripheral surface of the coil base.
The coil is wound in the auxiliary groove and
The plurality of displacement sensors and the slave station are connected in a string of beads.
Displacement measuring device.

(Appendix 15)
The plurality of displacement sensors are a first displacement sensor, a second displacement sensor, and a third displacement sensor.
The first displacement sensor measures the amount of displacement of the object to be measured in the X direction.
The second displacement sensor measures the amount of displacement of the object to be measured in the Y direction.
The third displacement sensor measures the amount of displacement of the object to be measured in the Z direction.
The displacement measuring device according to Appendix 14.

1 Displacement measuring device 11, 11A, 11B Shaft cap 12, 12A Metal shaft 13 Slider 14 Vent 15, 15B, 31 First air hole 16 Second air hole 21 Coil base 22 Coil 23 Displacement amount measuring unit 24 Auxiliary groove 25 Lid 26 1st case 27, 27B 2nd case 28 1st connector 29 2nd connector 30 Transmitter / receiver 40 Cover 100, 200, 300, 400, 500 Displacement sensor 600 Measured object 700 Slave station

Claims (10)

The shaft cap, which is the part that comes into contact with the object to be measured,
With the metal shaft connected to the shaft cap,
A coil base that is hollow and into which the metal shaft is inserted,
The coil wound around the outer peripheral surface of the coil base and
With a displacement amount measuring unit that measures the displacement amount of the metal shaft by measuring changes in the inductance and resistance of the coil as the metal shaft moves in the coil base while a current is flowing through the coil. With,
A spiral auxiliary groove is provided on the outer peripheral surface of the coil base.
The coil is wound in the auxiliary groove with a gap provided between the coil and the coil base.
Displacement sensor. The displacement sensor according to claim 1, wherein the auxiliary groove is provided in a V shape. The displacement sensor according to claim 1 or 2, further comprising a lid that covers the auxiliary groove. The displacement sensor according to any one of claims 1 to 3, wherein the metal shaft is hollow. Further provided with a slider connected to the metal shaft
The material of the slider is a material having good slidability.
The outer peripheral surface of the slider is in close contact with the inner peripheral surface of the coil base.
The displacement sensor according to any one of claims 1 to 4. Further provided with a first case for accommodating the coil base with the coil wound.
The first case is a metal case,
The displacement sensor according to any one of claims 1 to 5. With a magnetic sheet,
The magnetic sheet is arranged between the first case and the coil base.
The displacement sensor according to claim 6. The displacement sensor according to any one of claims 1 to 7, further comprising a second case for storing the displacement amount measuring unit. A first connector for receiving the measurement result of the displacement amount of the metal shaft in another displacement sensor, and
A second connector for transmitting at least one of the measurement result of the displacement amount of the metal shaft in the displacement amount measuring unit and the measurement result of the displacement amount of the metal shaft in the other displacement sensor.
A transmission / reception unit that receives at least one of the displacement measurement result via the first connector and the displacement measurement result via the second connector is further provided.
The displacement sensor according to any one of claims 1 to 8. Multiple displacement sensors that measure the amount of displacement in different directions on the object to be measured,
A slave station that receives the measurement result of the displacement amount in the plurality of displacement sensors is provided.
Each of the plurality of displacement sensors
The shaft cap, which is the part that comes into contact with the object to be measured,
With the metal shaft connected to the shaft cap,
A coil base that is hollow and into which the metal shaft is inserted,
The coil wound around the outer peripheral surface of the coil base and
With a displacement amount measuring unit that measures the displacement amount of the metal shaft by measuring changes in the inductance and resistance of the coil as the metal shaft moves in the coil base while a current is flowing through the coil. ,
A first connector for receiving the measurement result of the displacement amount of the metal shaft in another displacement sensor, and
A second connector for transmitting at least one of the measurement result of the displacement amount of the metal shaft in the displacement amount measuring unit and the measurement result of the displacement amount of the metal shaft in the other displacement sensor.
A transmission / reception unit for receiving at least one of a displacement measurement result via the first connector and a displacement measurement result transmission via the second connector is provided.
A spiral auxiliary groove is provided on the outer peripheral surface of the coil base.
The coil is wound around the auxiliary groove with a gap provided between the coil and the coil base.
The plurality of displacement sensors and the slave station are connected in a string of beads.
Displacement measuring device.

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