JP2021095926A - Looseness detection screw - Google Patents

Abstract

To strike a balance between enhancing accuracy for detecting looseness of a screw and facilitating detecting of looseness of a screw.SOLUTION: A looseness detection screw includes: a male screw including a first electrode of which screwing surface is at least partially formed of an electrical conductor; and a female screw including a second electrode and a third electrode which are electrically connected with the first electrode at being screwed together with the first electrode but electrically insulated each other, and varying the electrical conduction state between the second electrode and the third electrode depending on whether a first state where the female screw is sufficiently screwed together with the male screw or a second state where the female screw is not sufficiently screwed together with the male screw is established.SELECTED DRAWING: Figure 3

Description

The present invention relates to a screw capable of detecting looseness of the screw.

Patent Document 1 discloses an example of a technique for detecting looseness of a screw. The looseness detecting device for the tightening fixing member described in Patent Document 1 includes a pressure sensor. The looseness detection device is tightened and fixed by the tightening and fixing members (bolts and nuts) together with the fixed member. As a result of this configuration, the looseness detecting device described in Patent Document 1 detects looseness of the tightening fixing member based on the output (electrical resistance value) of the pressure-sensitive sensor.

Another example of a technique for detecting looseness of a screw is disclosed in Patent Document 2. The looseness detecting device for a screw member described in Patent Document 2 includes a detecting means for detecting a sound generated from a sliding contact portion between a female screw and a male screw. The looseness detecting device detects the release of the screwed state between the female screw and the male screw by analyzing the signal from the detecting means. As a result of this configuration, the looseness detection device described in Patent Document 2 detects the looseness state based on the output of the detection means.

Yet another example of a technique for detecting looseness of a screw is disclosed in Patent Document 3. The sensor-equipped fastener described in Patent Document 3 includes a posture detection sensor (including a 3-axis acceleration sensor and a 3-axis magnetic sensor). As a result of this configuration, the looseness detection system described in Patent Document 3 determines whether or not the fastener with the sensor is loose based on the time-series change in the output of the posture detection sensor.

Yet another example of a technique for detecting looseness of a screw is disclosed in Patent Document 4. In the automatic screw loosening detection method described in Patent Document 4, a pressure sensor (piezoelectric element) provided between two screwed members is used. As a result of this configuration, in the automatic detection method described in Patent Document 4, looseness of the screw is detected based on the output of the pressure sensor.

Japanese Unexamined Patent Publication No. 2014-228465 Japanese Unexamined Patent Publication No. 02-274441 JP-A-2019-007736 Japanese Unexamined Patent Publication No. 05-052684

In the techniques described in Patent Documents 1 to 4, various sensors are used to detect looseness of screws. Therefore, in order to improve the accuracy of screw loosening detection, it is necessary to improve the accuracy of various sensors. That is, in order to improve the accuracy of screw loosening detection, it is necessary to complicate, increase the size, or increase the cost of the detection means. In particular, when detecting the amount of rotation of a screw, it is necessary to convert the output of various sensors into the amount of rotation of the screw. It is necessary to increase the complexity, size, or cost.

Therefore, in the techniques described in Patent Documents 1 to 4, it is difficult to achieve both high accuracy of screw loosening detection and easy screw loosening detection (simplification, miniaturization, cost reduction, etc.). There was a problem.

The present invention has been made in view of the above problems, and a main object of the present invention is to achieve both high accuracy of screw loosening detection and easy screw loosening detection.

In one aspect of the present invention, the loosening detection screw is electrically connected to a male screw including a first electrode formed of an electric conductor on at least a part of the screwed surface, and to the first electrode when screwed to the first electrode, respectively. A second state, which includes a second electrode and a third electrode, which are insulated from each other, and which is sufficiently screwed with a male screw in a first state or insufficiently screwed with a male screw. It is provided with a female screw that changes the conduction state between the two electrodes and the third electrode.

According to the present invention, there is an effect that high accuracy of screw loosening detection and easy screw loosening detection can be achieved at the same time.

It is a schematic diagram which shows an example of the structure of the loosening detection screw in 1st Embodiment of this invention. It is a schematic diagram which shows an example of the structure of the loosening detection screw in the 2nd Embodiment of this invention. It is a schematic diagram which shows an example of the structure of the loosening detection screw in the 1st modification of 2nd Embodiment of this invention. It is a schematic diagram explaining the operation of the loosening detection screw in the 1st modification of the 2nd Embodiment of this invention. It is a schematic diagram which shows an example of the structure of the loosening detection screw in the 2nd modification of the 2nd Embodiment of this invention. It is a schematic diagram which shows an example of the structure of the loosening detection screw in the 3rd Embodiment of this invention. It is a schematic diagram which shows an example of the structure of the loosening detection screw in the modification of the 3rd Embodiment of this invention. It is a schematic diagram explaining the operation of the loosening detection screw in the modification of the 3rd Embodiment of this invention. It is a schematic diagram which shows an example of the structure of the loosening detection screw in 4th Embodiment of this invention. It is a schematic diagram which shows an example of the structure of the loosening detection screw in the modified example of 4th Embodiment of this invention. It is a schematic diagram explaining the operation of the loosening detection screw in the modified example of 4th Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In all the drawings, the same components are designated by the same reference numerals, and the description thereof will be omitted as appropriate.
(First Embodiment)
The first embodiment which is the basis of each embodiment of the present invention will be described.

The configuration in this embodiment will be described.

FIG. 1 is a schematic view showing an example of the configuration of a loosening detection screw according to the first embodiment of the present invention. In the drawings after FIG. 1 and the following description, the direction in which the looseness detection screw is installed is an example, and the direction in which the looseness detection screw is actually installed may be any direction. In the drawings after FIG. 1 and the following description, when viewed from a certain direction, the width (left and right) direction of the loosening detection screw is indicated by "X", the depth (front and back) direction is indicated by "Y", and the height ( The vertical) direction is indicated by "Z". That is, the X direction, the Y direction, and the Z direction are orthogonal to each other. In each of the X, Y, and Z directions, the right, back, and up directions are referred to as the "positive side," and the left, front, and down directions are referred to as the "negative side." Further, in the following description, the positive side in the X direction is the "X +" side, the negative side in the X direction is the "X-" side, the positive side in the Y direction is the "Y +" side, and the negative side in the Y direction is the negative side. The "Y-" side, the positive side in the Z direction are also referred to as the "Z +" side, and the negative side in the Z direction is also referred to as the "Z-" side. Further, in the drawings after FIG. 1 and the following description, an example in which the looseness detection screw is a right-hand screw is described, but the looseness detection screw may be a left-hand screw. Further, in FIG. 1, the illustration of the screw thread is omitted. Further, in FIG. 1, the part (A) shows the first state (described later), and the part (B) shows the second state (described later).

The loosening detection screw 100 in the present embodiment includes a male screw 200 and a female screw 300.

The male screw 200 includes an electrode 210 (an example of a first electrode).

The electrode 210 is formed of an electric conductor on at least a part of the threaded surface of the male screw 200 with the female screw 300. Here, "screw" means that a male screw and a female screw are fitted together.

The female screw 300 includes an electrode 320 (an example of a second electrode) and an electrode 330 (an example of a third electrode). The electrodes 210 and 320 change the conduction state (including the presence or absence of continuity) between the electrode 320 and the electrode 330 depending on whether the male screw 200 and the female screw 300 are in the first state or the second state. , And 330 are arranged. Here, in the first state, the male screw 200 and the female screw 300 are sufficiently screwed. The second state is a state in which the male screw 200 and the female screw 300 are not sufficiently screwed together. Further, the change in the conduction state may include a change in the resistance value.

The electrode 320 conducts with the electrode 210 when it is screwed into the electrode 210. Here, "screw connection" means that the male screw and the female screw are in contact with each other on at least a part of the surface on which the thread is formed in a state where the male screw and the female screw are fitted. Further, the arrangement of the electrodes 210, 320, and 330 described above will be exemplified in the following description of the embodiment.

The electrode 330 conducts with the electrode 210 when it is screwed into the electrode 210.

The electrode 320 and the electrode 330 are insulated from each other. In FIG. 1, the electrode 320 and the electrode 330 are insulated by an insulating portion 310. The insulating portion 310 may be an insulator or a void.

The operation in this embodiment will be described again with reference to FIG.

The conduction state between the electrode 320 and the electrode 330 changes depending on whether the female screw 300 is in the first state or the second state. For example, FIG. 1 shows an example in which the male screw 200 includes an insulating portion 220 formed of an insulator on a surface that can be screwed with the female screw 300. The state of contact between the electrode 330 and the electrode 210 (including the presence or absence of contact) changes depending on whether the female screw 300 is in the first state or the second state. As a result, the state of conduction (including the presence or absence of conduction) between the electrode 330 and the electrode 210 changes depending on whether the female screw 300 is in the first state or the second state.

As described above, in the looseness detection screw 100 in the present embodiment, the conduction state between the electrode 320 and the electrode 330 changes depending on whether the female screw 300 is in the first state or the second state. The loosening detection screw 100 includes electrodes 210, 320, and 330, but does not include sensors. Then, by appropriately designing the shapes of the electrodes 210, 320, and 330, or the relative positions of the electrodes 210, 320, and 330 in the first state and the second state, the looseness of the screw is not detected. And the range in which loosening of the screw is detected can be determined with high accuracy. Therefore, the looseness detecting screw 100 in the present embodiment has an effect that both high accuracy of screw loosening detection and easy screw loosening detection can be achieved at the same time.

In the loosening detection screw 100 of the present embodiment, in the first state, the electrode 210 conducts between the electrode 320 and the electrode 330, and in the second state, the electrode 210 conducts between the electrode 320 and the electrode 330. You do not have to let it.

Further, in the looseness detection screw 100 of the present embodiment, in the first state, the electrode 210 does not conduct conduction between the electrode 320 and the electrode 330, and in the second state, the electrode 210 moves between the electrode 320 and the electrode 330. It may be made conductive.

Further, in the loosening detection screw 100 in the present embodiment, the electrode 210 is formed of a good conductor, and the change in the conduction state may be a change in the presence or absence of continuity between the electrode 320 and the electrode 330.

Further, in the loosening detection screw 100 in the present embodiment, the electrode 210 is formed of a resistor, and the change in the conduction state may be a change in the resistance value between the electrode 320 and the electrode 330. In this case, there is an effect that the screwed state between the male screw 200 and the female screw 300 can be detected between the first state and the second state. Here, the "resistor" is a member having a relatively large resistance (metal thick film, metal thin film, metal oxide film, carbon film, the above-mentioned member having a limited contact area, an insulator) used for a variable resistor or the like. It is assumed that it is the above-mentioned member or the like in which particles are mixed). Then, as the screwed state of the male screw 200 and the female screw 300 changes, for example, the contact area between the electrode 210 and the electrode 320 or 330 changes, so that the electrode 210 (slider / resistance of the variable resistor) changes. (Corresponding to the body), electrodes 320, 330 (corresponding to the resistor / slider of the variable resistor) are arranged.

Further, in the loosening detection screw 100 in the present embodiment, the male screw 200 may include an insulating portion 220 formed of an insulator on a surface that can be screwed with the female screw 300. In this case, there is an effect that the design of the shape or the relative position of the electrodes 210, 320, and 330 becomes easier.

Further, in the loosening detection screw 100 in the present embodiment, the electrode 320 and the electrode 330 may be urged to maintain contact with the male screw 200. In this case, there is an effect that the contact between the electrode 320 and the electrode 330 and the male screw 200 is more reliable.
(Second Embodiment)
A second embodiment based on the first embodiment of the present invention will be described. In the present embodiment, the rotation of the male screw 201 (male screw 200 of the first embodiment) with respect to the female screw 300 in the first state and the second state is detected. Further, in the first state, the electrode 211 (the electrode 210 of the first embodiment) conducts between the electrode 320 and the electrode 330, and in the second state, the electrode 210 does not conduct between the electrode 320 and the electrode 330. ..

The configuration in this embodiment will be described.

FIG. 2 is a schematic view showing an example of the configuration of the looseness detection screw according to the second embodiment of the present invention. In FIG. 2, the part (A) shows the first state, and the part (B) shows the second state. Further, in FIG. 2, the illustration of the screw thread is omitted.

The loosening detection screw 101 in the present embodiment includes a male screw 201 and a female screw 300.

The male screw 201 includes an insulating portion 221.

The insulating portion 221 is formed of an insulator on the surface of the male screw 201 that can be screwed with the female screw 300.

The male screw 201 includes electrodes 211a and 211b (an example of a fourth electrode and a fifth electrode). Here, in FIG. 1, the electrodes 211a and 211b are the sides of both ends of one electrode plate, respectively.

The electrodes 211a and 211b are formed of an electric conductor on at least a part of the threaded surface of the male screw 201 with the female screw 300.

The electrode 320 conducts with the electrode 211a when it is screwed with the electrode 211a, and conducts with the electrode 211b when it is screwed with the electrode 211b.

The electrode 330 conducts with the electrode 211a when it is screwed with the electrode 211a, and conducts with the electrode 211b when it is screwed with the electrode 211b.

The electrodes 211a and 211b are separated from each other by the insulating portion 221 on the surface that can come into contact with the electrodes 211a or 211b when screwed with the female screw 300, and are electrically connected to each other.

In the first state, the electrodes 211a and 211b are exclusively screwed to either the electrode 320 or the electrode 330, respectively.

In the second state, the electrodes 211a and 211b do not screw into either the electrode 320 or the electrode 330.

Other configurations in this embodiment are the same as those in the first embodiment.

The operation in this embodiment will be described again with reference to FIG.

In the first state, the electrodes 211a and 211b make the electrodes 320 and 330 conductive.

In the second state, the electrodes 211a and 211b do not conduct between the electrodes 320 and 330.

That is, in the loosening detection screw 101, in the first state, the electrodes 211a and 211b conduct between the electrodes 320 and the electrodes 330, and in the second state, the electrodes 211a and 211b conduct between the electrodes 320 and the electrodes 330. I won't let you.

The other operations in this embodiment are the same as the operations in the first embodiment.

As described above, the looseness detection screw 101 in the present embodiment can detect looseness of the screw corresponding to less than one rotation of the male screw 201 (less than one quarter rotation in the example shown in FIG. 2). is there. Therefore, the looseness detection screw 101 in the present embodiment has an effect that the looseness detection of the screw can be made more accurate in addition to the effect in the first embodiment.
(First modification)
A first modification of the present embodiment will be described.

The configuration in this modification will be described.

FIG. 3 is a schematic view showing an example of the configuration of the loosening detection screw in the first modification of the second embodiment of the present invention. In FIG. 3, the screw thread is not shown.

The loosening detection screw 1010 of this modification includes a male screw 2010, a female screw 3010, and a computer 3016.

The male screw 2010 includes a male screw base material 2211, a male screw electrode 2111a, and a male screw electrode 2111b (an example of a fourth electrode and a fifth electrode).

The male screw base material 2211 is a base material constituting the male screw 2010, and is made of an insulator.

The male screw electrodes 2111a and 2111b are electrodes embedded in the male screw 2010, respectively. The male screw electrodes 2111a and 2111b are connected to each other inside the male screw 2010.

The female screw 3010 includes a female screw base material 3101, a female screw electrode 3201, and a female screw electrode 3301 (an example of a second electrode and a third electrode).

The female screw base material 3101 is a base material constituting the female screw 3010 and is made of an insulator.

The female screw electrodes 3201 and 3301 are electrodes embedded in the female screw 3010, respectively.

The communication line 3015 is a communication line for detecting the looseness of the looseness detection screw 1010 as non-conduction between the female screw electrodes 3201 and 3301 and transmitting the looseness to the computer 3016.

The computer 3016 is an information device that receives looseness information (presence or absence of continuity, etc.) detected by the looseness detection screw 1010 via the communication line 3015 and processes it.

Other configurations in this modification are the same as the configurations in this embodiment.

The operation in this modification will be described with reference to FIGS. 3 and 4.

FIG. 4 is a schematic view illustrating the operation of the loosening detection screw in the first modification of the second embodiment of the present invention. In FIG. 4, the part (C) shows the first state, the part (A) shows the second state, and the part (B) shows the intermediate state between the first state and the second state.

(1) The male screw 2010 is inserted into the female screw 3010 (FIG. 3).

(2) It is assumed that the male screw electrode 2111a and the female screw electrode 3201 and the male screw electrode 2111b and the female screw electrode 3301 are arranged in advance at positions facing each other when the loosening detection screw 1010 is closed (FIG. 4 (C)). ..

(3) With the loosening detection screw 1010 closed, the male screw electrode 2111a and the female screw electrode 3201 and the male screw electrode 2111b and the female screw electrode 3301 are connected (FIG. 4 (C)). Since the male screw electrodes 2111a and 2111b are connected to each other inside the male screw 2010, the female screw electrode 3201 and the female screw electrode 3301 are conducted by the male screw electrodes 2111a and 2111b.

(4) After the looseness detection screw 1010 is closed, the looseness detection screw 1010 is started to be monitored for looseness (FIG. 4 (C)). The looseness information is notified to the computer 3016 through the communication line 3015. No monitoring is performed until the looseness detection screw 1010 is closed.

(5) If there is continuity between the female screw electrode 3201 and the female screw electrode 3301, the computer 3016 determines that the loosening detection screw 1010 is not loose (FIGS. 4C and 4B).

(6) When the looseness detection screw 1010 is loosened and the connection between the male screw electrode 2111a and the female screw electrode 3201 and the connection between the male screw electrode 2111b and the female screw electrode 3301 is disconnected, the female screw electrode 3201 and the female screw electrode 3301 The continuity between them is lost (FIG. 4 (A)). Then, the computer 3016 is notified of the looseness information that the continuity between the female screw electrode 3201 and the female screw electrode 3301 is lost through the communication line 3015.

Here, the detected loosening width can be adjusted by changing the size and arrangement of the male screw electrodes 2111a or 2111b or the female screw electrodes 3201 or 3301.

Other operations in this modification are the same as the operations in this embodiment.

As described above, in the loosening detection screw 1010 in the present modification, the detected loosening width can be adjusted by changing the size and arrangement of the male screw electrode 2111a or 2111b or the female screw electrode 3201 or 3301. .. Therefore, the looseness detection screw 1010 in the present modification has the effect that, in addition to the effect in the present embodiment, it is easier to realize the detection condition for the looseness detection of the screw.
(Second modification)
A second modification of the present embodiment will be described.

FIG. 5 is a schematic view showing an example of the configuration of the loosening detection screw in the second modification of the second embodiment of the present invention. Specifically, FIG. 5 shows a modified example of the female screw electrode.

In this modification, the loosening detection screw 1010 has two or more pairs of female screw electrodes and the same number of male screw electrodes (not shown) as the female screw electrodes. Here, the female screw electrodes are insulated from each other. Further, each of the pair of female screw electrodes is installed at a position facing each other on the circumference of the female screw. The number of pairs of female thread electrodes and the width of each female thread electrode on the circumference are determined according to the range and size of the looseness to be detected. The circumferential width of each male screw electrode shall be smaller than the circumferential width of the gap between adjacent female screw electrodes. Then, the conduction state between each pair of female screw electrodes is detected individually or in a plurality of pairs.

In this modification, in addition to the effect in this modification, it is sufficient that any one pair of female screw electrodes are conducting in the first state, so that the positional relationship between the male screw and the female screw in the first state is sufficient. Has the effect of being easier to design and realize.
(Third Embodiment)
A third embodiment based on the first embodiment of the present invention will be described. In the present embodiment, the rotation of the male screw 202 (male screw 200 of the first embodiment) with respect to the female screw 300 in the first state and the second state is detected. Further, in the first state, the electrode 212 (the electrode 210 of the first embodiment) does not conduct between the electrode 320 and the electrode 330, and in the second state, the electrode 210 conducts between the electrode 320 and the electrode 330. Let me. The present embodiment is the same as the second embodiment except that conduction / non-conduction is reversed.

The configuration in this embodiment will be described.

FIG. 6 is a schematic view showing an example of the configuration of the looseness detection screw according to the third embodiment of the present invention. In FIG. 6, the part (A) shows the first state, and the part (B) shows the second state. Further, in FIG. 6, the illustration of the screw thread is omitted.

The loosening detection screw 102 in this embodiment includes a male screw 202 and a female screw 300.

The male screw 202 includes an electrode 212 (an example of a first electrode) and an insulating portion 222.

The electrode 212 is formed of an electric conductor on the surface of the male screw 202 that can be screwed with the female screw 300.

The insulating portion 222 is formed of an insulator on the surface of the male screw 202 that can be screwed with the female screw 300.

In the first state, the electrode 212 (an example of the first electrode) does not screw into the electrode 320 or the electrode 330.

In the second state, the electrode 212 is screwed into the electrode 320 and the electrode 330.

Other configurations in this embodiment are the same as those in the first embodiment.

The operation in this embodiment will be described again with reference to FIG.

In the first state, the electrode 212 does not conduct between the electrode 320 and the electrode 330.

In the second state, the electrode 212 conducts between the electrode 320 and the electrode 330.

That is, in the loosening detection screw 102, in the first state, the electrode 212 does not conduct between the electrode 320 and the electrode 330, and in the second state, the electrode 212 conducts between the electrode 320 and the electrode 330.

The other operations in this embodiment are the same as the operations in the first embodiment.

As described above, the looseness detection screw 102 in the present embodiment can detect looseness of the screw corresponding to less than one rotation of the male screw 202 (less than one quarter rotation in the example shown in FIG. 6). is there. Therefore, the looseness detection screw 102 in the present embodiment has an effect that the looseness detection of the screw can be made more accurate in addition to the effect in the first embodiment.
(Modification example)
A modified example of this embodiment will be described.

The configuration in this modification will be described.

FIG. 7 is a schematic view showing an example of the configuration of the loosening detection screw in the modified example of the third embodiment of the present invention. In FIG. 7, the part (A) shows a front view (cross-sectional view) of the detection screw in the XZ plane, and the part (B) shows a partially enlarged view in the first state, (C). Part shows a partially enlarged view of the second state.

The loosening detection screw 1020 of this modification includes a male screw 2020, a female screw 3020, and a computer 3016.

The male screw 2020 includes a male screw base material 2121 (an example of a first electrode) and a male screw insulating portion 2222 (an example of an insulating portion).

The male screw base material 2121 is a base material constituting the male screw 2020 and is made of a conductor.

The male screw insulating portion 2222 is an insulator embedded in the male screw 2020.

The female screw 3020 includes a female screw base material 3023, a female screw electrode 3202, a female screw electrode 3302 (an example of a second electrode and a third electrode), a female screw insulating portion 3127, and a spring portion 3208.

The female screw base material 3023 is a base material constituting the female screw 3020, and is composed of a conductor. The female thread base material 3023 is usually connected to the ground.

The female screw electrodes 3202 and 3302 are electrodes embedded in the female screw 3020, respectively. The female screw electrode 3302 may have the same shape as the female screw electrode 3202. However, the female screw electrode 3302 may maintain the state of being connected to the male screw base material 2121 when the connection state of the female screw electrode 3202 and the male screw base material 2121 changes.

The communication line 3015 is a communication line for detecting the looseness of the looseness detection screw 1020 as continuity between the female screw electrodes 3202 and 3302 and transmitting the looseness to the computer 3016.

The computer 3016 is an information device that receives looseness information (presence or absence of continuity, etc.) detected by the looseness detection screw 1020 via the communication line 3015 and processes it.

The female screw insulating portion 3127 is a member that prevents the female screw electrode 3202 from coming into contact with the female screw base material 3023.

The spring portion 3208 is a spring or an elastic body for ensuring contact of the female screw electrode 3202 with the male screw 2020 and preventing damage to the female screw electrode 3202.

Other configurations in this modification are the same as the configurations in this embodiment.

The operation in this modification will be described.

FIG. 8 is a schematic view illustrating the operation of the looseness detection screw in the modified example of the third embodiment of the present invention. In FIG. 8, the part (A) shows the first state, the part (C) shows the second state, and the part (B) shows the intermediate state between the first state and the second state.

(1) When the loosening detection screw 1020 is closed, the female screw electrode 3202 and the male screw insulating portion 2222 come into contact with each other (FIG. 8 (A)). Here, the width of the detected looseness can be adjusted by adjusting the size and arrangement of the male screw insulating portion 2222.

(2) After the looseness detection screw 1020 is closed, the looseness detection screw 1020 is started to be monitored for looseness (FIG. 8 (A)). No monitoring is performed until the looseness detection screw 1020 is closed. Normally, the potential of the female screw electrode 3202 is set to a value different from the ground potential after the deadline of the loosening detection screw 1020 is completed.

(3) When the loosening detection screw 1020 is loosened, the female screw electrode 3202 is detached from the male screw insulating portion 2222, and the female screw electrode 3202 is pushed out by the spring portion 3208 and comes into contact with the male screw base material 2121.

(4) Since the male screw base material 2121 is in contact with the female screw base material 3023 at another point (female screw electrode 3302), the female screw base material 2121 and the female screw base material 3023 are passed through the female screw base material 2121. The electrode 3202 is short-circuited to the ground.

(5) The fact that the female screw electrode 3202 is short-circuited to the ground is transmitted to the computer 3016 via the communication line 3015, and it is detected that the loosening detection screw 1020 has loosened (FIG. 8 (C)). ..

Other operations in this modification are the same as the operations in this embodiment.

As described above, in the loosening detection screw 1020 in this modification, the male screw insulating portion 2222 insulates the male screw 2020 and the female screw 3020 in the first state. That is, the detected loosening width can be adjusted by changing the width of the male screw insulating portion 2222 in the rotation direction of the male screw 2020 (in the XY plane). Therefore, the looseness detection screw 1020 in the present modification has the effect that, in addition to the effect in the present embodiment, it is easier to adjust the detection conditions for screw looseness detection.
(Fourth Embodiment)
A fourth embodiment based on the first embodiment of the present invention will be described. In the present embodiment, the vertical movement of the male screw 203 (male screw 200 of the first embodiment) with respect to the female screw 300 in the first state and the second state is detected. Further, in the first state, the electrode 213 (the electrode 210 of the first embodiment) conducts between the electrode 320 and the electrode 330, and in the second state, the electrode 213 does not conduct between the electrode 320 and the electrode 330. ..

The configuration in this embodiment will be described.

FIG. 9 is a schematic view showing an example of the configuration of the looseness detection screw according to the fourth embodiment of the present invention. In FIG. 9, the part (A) shows the first state, and the part (B) shows the second state. Further, in FIG. 9, the illustration of the screw thread is omitted.

The loosening detection screw 103 in the present embodiment includes a male screw 203 and a female screw 300.

The male screw 203 includes an electrode 213 (an example of the first electrode).

The electrode 213 is formed of an electric conductor at least a part of the threading surface of the male screw 203 with the female screw 300 (a predetermined position in the screwing direction of the male screw 203 with respect to the female screw 300; Z + side in FIG. 9). To.

The electrode 320 and the electrode 330 are screwed to the electrode 213 at a position in the screwing direction of the electrode 213 with respect to the female screw 300 in the first state. Here, "screw feeding" means screw feeding in a state where the male screw and the female screw are fitted together.

At least one of the electrode 320 or the electrode 330 does not screw with the electrode 213 at the position of the electrode 213 in the screwing direction with respect to the female screw 300 in the second state.

The male screw 203 may include an insulating portion 223 formed of an insulator on a surface that can be screwed with the female screw 300.

Other configurations in this embodiment are the same as those in the first embodiment.

The operation in this embodiment will be described again with reference to FIG.

In the first state, the electrode 213 conducts between the electrode 320 and the electrode 330.

In the second state, the electrode 213 does not conduct between the electrode 320 and the electrode 330.

That is, in the loosening detection screw 103, in the first state, the electrode 213 conducts between the electrode 320 and the electrode 330, and in the second state, the electrode 213 does not conduct between the electrode 320 and the electrode 330. In this embodiment, the conduction / non-conduction between the electrode 320 and the electrode 330 may be reversed.

The other operations in this embodiment are the same as the operations in the first embodiment.

As described above, in the loosening detection screw 103 of the present embodiment, the electrode 213 of the male screw 203 is formed at a predetermined position in the screwing direction. Therefore, the looseness detection screw 103 in the present embodiment has an effect that the structure can be further simplified in addition to the effect in the first embodiment.
(Modification example)
A modified example of this embodiment will be described.

The configuration in this modification will be described.

FIG. 10 is a schematic view showing an example of the configuration of the loosening detection screw in the modified example of the fourth embodiment of the present invention. In FIG. 10, the part (A) shows the front view (cross-sectional view) of the detection screw in the XY plane, and the part (B) shows the top view (cross-sectional view) in the XY plane.

The loosening detection screw 1030 of this modification includes a male screw 2030, a female screw 3030, and a computer 3016.

The male screw 2030 includes a male screw base material 2031 (an example of a first electrode).

The male screw base material 2031 is a base material constituting the male screw 2030, and is made of a conductor (insulator).

The female screw 3030 includes a female screw base material 3032, a female screw electrode 3203, a female screw electrode 3303 (an example of a second electrode and a third electrode), a female screw insulating portion 3133, and a spring portion 3307.

The female screw base material 3032 is a base material constituting the female screw 3030 and is made of a conductor. The female thread base material 3032 is usually connected to the ground.

The female screw insulating portion 3133 is an insulating portion embedded in the female screw 3030, and prevents conduction between the female screw electrodes 3203 and 3303 and the female screw base material 3032.

The female screw electrodes 3203 and 3303 are electrode portions embedded in the female screw 3030.

The communication line 3015 is a communication line for detecting the looseness of the looseness detection screw 1030 as non-conduction between the female screw electrodes 3203 and 3303 and transmitting the looseness to the computer 3016.

The computer 3016 is an information device that receives looseness information (presence or absence of continuity, etc.) detected by the looseness detection screw 1030 via the communication line 3015 and processes it.

The spring portion 3307 is a spring or an elastic body for ensuring contact of the female screw electrodes 3203 and 3303 with the male screw 2030 and preventing damage to the female screw electrodes 3203 and 3303.

Other configurations in this modification are the same as the configurations in this embodiment.

The operation in this modification will be described.

FIG. 11 is a schematic view illustrating the operation of the loosening detection screw in the modified example of the fourth embodiment of the present invention. In FIG. 11, the part (A) shows the first state, the part (C) shows the second state, and the part (B) shows the intermediate state between the first state and the second state.

(1) After the looseness detection screw 1030 is closed, the female screw electrode 3203 is installed at the highest position (Z + side) on the thread of the male screw 2030 where loosening in the Z direction is allowed (FIG. 10 (A)).

(2) Normally, the potential of the female screw electrode 3203 is set to a value different from the ground potential before the deadline of the loosening detection screw 1030 is completed.

(3) When the looseness detection screw 1030 is closed, the female screw electrode 3203 and the male screw base material 2031 come into contact with each other. The spring portion 3307 prevents damage to the female screw electrodes 3203 and 3303.

(4) After the looseness detection screw 1030 is closed, the looseness detection screw 1030 is started to be monitored for looseness (FIG. 11 (A)). No monitoring is performed until the looseness detection screw 1030 is closed. The potential of the female screw electrode 3203 becomes the ground potential when the deadline of the loosening detection screw 1030 is completed.

(5) When the loosening detection screw 1030 is loosened, the contact of the female screw electrode 3203 with the male screw base material 2031 is released, and the potential of the female screw electrode 3203 becomes a potential different from that of the ground.

(6) The fact that the female screw electrode 3203 is out of contact with the male screw base material 2031 is transmitted to the computer 3016 via the communication line 3015, and it is detected that the loosening detection screw 1030 has loosened (6). FIG. 11 (C).

Other operations in this modification are the same as the operations in this embodiment.

As described above, in the loosening detection screw 1030 in this modification, the male screw 2030 may be a general screw made of a conductor. Therefore, the loosening detection screw 1030 in this modification has an effect that the structure can be further simplified in addition to the effect in the fourth embodiment.

The present invention has been exemplified above by way of each of the above-described embodiments and modifications thereof. However, the technical scope of the present invention is not limited to the scope described in each of the above-described embodiments and modifications thereof. It will be apparent to those skilled in the art that various changes or improvements can be made to such embodiments. In such cases, new embodiments with such modifications or improvements may also be included in the technical scope of the invention. And this is clear from the matters stated in the claims.

INDUSTRIAL APPLICABILITY The present invention can be used in applications for detecting looseness of screws in electrical equipment, buildings, railway equipment, machines, moving objects, and the like.

100, 101, 102, 103, 1010, 1020, 1030 Loosening detection screw 200, 201, 202, 203, 2010, 2020, 2030 Male screw 210, 211, 212, 213 Electrode 220, 221 222, 223 Insulation part 300, 3010, 3011, 3020, 3030 Female thread 310 Insulation part 320, 330 Electrode 2031, 2121, 2211 Male thread base material 2111 Male thread electrode 2222 Male thread insulation part 3015 Communication line 3016 Computer 3101, 3023, 3032 Female thread base material 3127, 3133 Female screw insulation part 3201, 3202, 3203, 3301, 3302, 3303 Female screw electrode 3208, 3307 Spring part

Claims (10)

A male screw containing a first electrode formed of an electric conductor on at least a part of the threaded surface,
Each includes a second electrode and a third electrode, which are electrically connected to the first electrode when screwed to the first electrode and are insulated from each other.
The conduction state between the second electrode and the third electrode depends on whether the screwing with the male screw is sufficient in the first state or the screwing with the male screw is insufficient in the second state. Loosening detection screw with variable female screw. The looseness detection screw according to claim 1, wherein the second electrode and the third electrode are urged to maintain contact with the male screw. The first electrode is made of a good conductor.
The looseness detection screw according to claim 1 or 2, wherein the change in the conduction state is a change in the presence or absence of continuity between the second electrode and the third electrode. The first electrode is formed of a resistor and is formed of a resistor.
The looseness detection screw according to claim 3, wherein the change in the conduction state includes a change in the resistance value between the second electrode and the third electrode. The second electrode and the third electrode are screwed to the first electrode at a position in the screwing direction of the first electrode with respect to the female screw in the first state, and the second electrode or the third electrode The looseness detection screw according to any one of claims 1 to 4, wherein at least one of the above is not screwed with the first electrode at the position of the first electrode in the screwing direction with respect to the female screw in the second state. .. The looseness detection screw according to any one of claims 1 to 4, wherein the male screw includes an insulating portion formed of an insulator on a surface that can be screwed with the female screw. In the first state, the first electrode conducts between the second electrode and the third electrode.
The looseness detection screw according to claim 6, wherein in the second state, the first electrode does not conduct conduction between the second electrode and the third electrode. The first electrode includes a fourth electrode and a fifth electrode that are separated from each other by the insulating portion on a surface that can come into contact with the first electrode when screwed with the female screw and are conductive to each other. ,
In the first state, the fourth electrode and the fifth electrode are exclusively screwed to either the second electrode or the third electrode, respectively.
The looseness detection screw according to claim 7, wherein in the second state, the fourth electrode and the fifth electrode do not screw into either the second electrode or the third electrode. In the first state, the first electrode does not conduct between the second electrode and the third electrode.
The looseness detection screw according to claim 6, wherein in the second state, the first electrode is conductive between the second electrode and the third electrode. In the first state, the first electrode does not screw into the second electrode or the third electrode.
The looseness detection screw according to claim 9, wherein in the second state, the first electrode is screwed into the second electrode and the third electrode.

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