JP7374002B2 - Electromagnetic coil device and switch - Google Patents

Description

The present disclosure relates to an electromagnetic coil device and a switch having molded resin.

Some operating mechanisms for closing and opening a switch include a fixed coil and a moving coil. The moving coil is fixed to a moving shaft connected to a moving electrode. The movable coil is capable of reciprocating movement between the direction of being drawn toward the fixed coil and the direction of being pulled away from the fixed coil. In such an operating mechanism, when the moving coil is drawn toward the fixed coil, the moving coil collides with the fixed coil, thereby applying an impact force to the fixed coil and the moving coil. The operating mechanism is required to be able to suppress damage to the movable coil and the fixed coil due to application of impact force.

Patent Document 1 discloses an operating mechanism using an electromagnetic coil device including a resin-molded coil conductor as a movable coil. In the operating mechanism according to Patent Document 1, the rigidity of the electromagnetic coil device is increased by further housing a coil conductor molded with resin in a case.

Japanese Patent Application Publication No. 2002-124162

According to the prior art disclosed in Patent Document 1, in the electromagnetic coil device, the molded coil conductor is further reinforced by a case. Due to the need for a reinforcing structure such as the case, the electromagnetic coil device according to the prior art has a problem in that it takes a long time to manufacture and requires a lot of effort to manufacture. When a molded coil conductor is used in an operating mechanism without being housed in a case, it becomes difficult to prevent separation of the coil conductor from the mold resin and to prevent cracks from forming in the mold resin. As described above, according to the prior art, it has been difficult to suppress the peeling of the mold resin and the occurrence of cracks in the electromagnetic coil device with a configuration that can be easily manufactured.

The present disclosure has been made in view of the above, and an object of the present disclosure is to obtain an electromagnetic coil device that can be easily manufactured and that can suppress peeling of mold resin and generation of cracks.

In order to solve the above-mentioned problems and achieve the objectives, an electromagnetic coil device according to the present disclosure is arranged between a coil conductor, a molded resin that covers the coil conductor, and a coil conductor and the molded resin. and an inner layer portion made of a resin having a low elastic modulus. The inner layer portion has a first surface that is in contact with the coil conductor, and a second surface that is opposite to the first surface and that is in contact with the mold resin. The thickness of the portion of the mold resin that is in contact with the second surface is 10 to 20 times the thickness of the inner layer between the first and second surfaces.

The electromagnetic coil device according to the present disclosure can be easily manufactured, and has the advantage of suppressing mold resin peeling and cracking.

Cross-sectional view of the electromagnetic coil device according to the first embodiment A diagram for explaining the relationship between the elastic modulus and impact resistance of the inner layer of the electromagnetic coil device according to the first embodiment. A diagram for explaining the relationship between the thickness of the inner layer and impact resistance of the electromagnetic coil device according to the first embodiment. A diagram for explaining the relationship between the ratio of the thickness of the mold resin and the inner layer portion and the impact resistance in the electromagnetic coil device according to the first embodiment. A diagram for explaining the relationship between the bending strength and impact resistance of the molded resin of the electromagnetic coil device according to the first embodiment. Cross-sectional view of a switch according to Embodiment 2 Cross-sectional view of an electromagnetic drive unit included in a switch according to a second embodiment

EMBODIMENT OF THE INVENTION Below, the electromagnetic coil apparatus and switch concerning embodiment are demonstrated in detail based on drawing. Note that the present disclosure is not limited to this embodiment.

Embodiment 1.
FIG. 1 is a sectional view of the electromagnetic coil device according to the first embodiment. The electromagnetic coil device 1 according to the first embodiment is used in a switch operating mechanism. The electromagnetic coil device 1 includes a coil conductor 2, a molded resin 3 covering the coil conductor 2, and two inner layer parts 4. Each inner layer portion 4 is arranged between the end surface of the coil conductor 2 and the mold resin 3. Each inner layer portion 4 is made of a resin having a lower elastic modulus than that of the mold resin 3. The electromagnetic coil device 1 also includes a current terminal 5 and a lead wire 6 that connects the current terminal 5 and the coil conductor 2.

The coil conductor 2 is an annularly wound metal wire. Lead wire 6 is connected to the end of the metal wire. The mold resin 3 has an annular appearance. FIG. 1 shows a cross section of the coil conductor 2 in the axial direction, passing through a part other than the center of the annular shape. Each inner layer portion 4 has a first surface 7 that is in contact with the coil conductor 2 and a second surface 8 that is opposite to the first surface 7 and that is in contact with the mold resin 3. The thickness of the portion of the mold resin 3 that is in contact with the second surface 8 is d1. The thickness of the inner layer portion 4 between the first surface 7 and the second surface 8 is d2.

The electromagnetic coil device 1 relieves impact stress when an impact is applied to the electromagnetic coil device 1 by using the double structure of the molded resin 3 and the inner layer portion 4. The electromagnetic coil device 1 can suppress peeling between the mold resin 3 and the inner layer portion 4 and generation of cracks in the mold resin 3 by relaxing the impact stress. In addition, in the following description, the peeling between the mold resin 3 and the inner layer portion 4 may be simply referred to as "peeling". Furthermore, cracks in the mold resin 3 are sometimes simply referred to as "cracks."

In the manufacturing process of the electromagnetic coil device 1, resin, which is the material of the inner layer portion 4, is applied to the coil conductor 2. By curing the applied resin, an inner layer portion 4 bonded to the coil conductor 2 is formed. The electromagnetic coil device 1 including the molded resin 3 is formed by molding the coil conductor 2 and the inner layer portion 4, which are integral with each other, with the material of the molded resin 3. The inner layer portion 4 can be easily formed by applying and curing a resin. Compared to the conventional case in which a molded coil is housed in a case, the electromagnetic coil device 1 can shorten the time required for manufacturing and can reduce manufacturing costs. The electromagnetic coil device 1 can be manufactured more easily than in the conventional case.

Next, the characteristics of the mold resin 3 and the inner layer portion 4 used in the electromagnetic coil device 1 will be described with reference to FIGS. 2 to 5. Here, we prepared a switch in which the electromagnetic coil device 1 is used for the fixed coil and the movable coil, made the switch perform closing and opening operations, and tested the impact resistance of the electromagnetic coil device 1. Based on this, the relationship between the characteristics and impact resistance of the mold resin 3 and the inner layer portion 4 will be explained.

Each of FIGS. 2 to 5 shows the results of determining the presence or absence of impact resistance based on the state of peeling and crack occurrence during 1000 operations using a switch. In each of FIGS. 2 to 5, "fair" indicates that no peeling or cracking occurs in the test, and that the electromagnetic coil device 1 has impact resistance that can withstand use in a switch. "Unacceptable" indicates that peeling or cracking occurred in the test, and that peeling or cracking may occur when the electromagnetic coil device 1 is used in a switch.

FIG. 2 is a diagram for explaining the relationship between the elastic modulus and impact resistance of the inner layer portion of the electromagnetic coil device according to the first embodiment. FIG. 2 shows the results of a test in which the modulus of elasticity of the inner layer portion 4 was changed stepwise from 0.05 GPa to 5.0 GPa, and the impact resistance was determined for each modulus of elasticity. In this test, except for changing the elastic modulus of the inner layer 4, the properties of the mold resin 3 and the inner layer 4 are assumed to be constant.

In FIG. 2, the judgment result when the elastic modulus of the inner layer part 4 is from 0.1 GPa to 4.0 GPa is "fair", and the judgment result when the elastic modulus of the inner layer part 4 is 0.05 GPa and the elastic The determination result when the rate is 5.0 GPa is "impossible". From this, it can be seen that the appropriate elastic modulus is from 0.1 GPa to 4.0 GPa. If the elastic modulus of the inner layer portion 4 is lower than the appropriate elastic modulus, the cushioning properties provided by the inner layer portion 4 will be insufficient, and cracks will likely occur. Furthermore, if the elastic modulus of the inner layer portion 4 is higher than the appropriate elastic modulus, peeling is likely to occur. Therefore, in the electromagnetic coil device 1, since the elastic modulus of the inner layer portion 4 is 0.1 GPa or more and 4.0 GPa or less, peeling of the mold resin 3 and generation of cracks can be suppressed.

FIG. 3 is a diagram for explaining the relationship between the thickness and impact resistance of the inner layer of the electromagnetic coil device according to the first embodiment. FIG. 3 shows the results of a test in which the thickness d2 of the inner layer portion 4 was changed stepwise from 0.4 mm to 1.1 mm, and the impact resistance was determined for each thickness. In this test, except for changing the thickness of the inner layer 4, the properties of the mold resin 3 and the inner layer 4 are assumed to be constant.

In FIG. 3, the judgment result when the thickness of the inner layer part 4 is from 0.5 mm to 1.0 mm is "fair", and the judgment result when the thickness of the inner layer part 4 is 0.4 mm and the inner layer The determination result when the thickness of the portion 4 is 1.1 mm is "not acceptable". From this, it can be seen that the appropriate thickness is 0.5 mm to 1.0 mm. If the thickness of the inner layer portion 4 is thinner than the appropriate thickness, the cushioning properties provided by the inner layer portion 4 will be insufficient, and cracks will likely occur. Further, if the thickness of the inner layer portion 4 is thicker than an appropriate thickness, peeling is likely to occur. Therefore, in the electromagnetic coil device 1, when the thickness of the inner layer portion 4 is 0.5 mm or more and 1.0 mm or less, peeling of the mold resin 3 and generation of cracks can be suppressed.

FIG. 4 is a diagram for explaining the relationship between the ratio of the thickness of the mold resin and the inner layer portion and the impact resistance in the electromagnetic coil device according to the first embodiment. The thickness of the molded resin 3 in this description is d1, which is the thickness of the portion of the molded resin 3 that is in contact with the second surface 8. FIG. 4 shows the results of a test in which the ratio of d1 to d2 was changed stepwise from 8 to 22, and the impact resistance was determined for each ratio. In this test, it is assumed that the properties of the mold resin 3 and the inner layer portion 4 are all constant except that the ratio of d1 to d2 is changed.

In FIG. 4, the judgment result when the ratio of d1 to d2 is 10 to 20 is "fair", and the judgment result when the ratio is 8 and the judgment result when the ratio is 22 are both different. It is "not possible". From this, it can be seen that 10 to 20 is an appropriate ratio. If the ratio of d1 to d2 is smaller than the appropriate ratio, peeling is likely to occur. Furthermore, if the ratio of d1 to d2 is larger than the appropriate ratio, the cushioning properties provided by the inner layer portion 4 will be insufficient, and cracks will likely occur. Therefore, in the electromagnetic coil device 1, the thickness of the portion of the molded resin 3 in contact with the second surface 8 is 10 to 20 times the thickness of the inner layer portion 4 between the first surface 7 and the second surface 8. By doing so, it becomes possible to suppress peeling of the mold resin 3 and generation of cracks.

FIG. 5 is a diagram for explaining the relationship between the bending strength and impact resistance of the molded resin included in the electromagnetic coil device according to the first embodiment. FIG. 5 shows the results of a test in which the bending strength of the mold resin 3 was changed stepwise from 90 MPa to 160 MPa, and the impact resistance was determined for each bending strength. In this test, it is assumed that the properties of the mold resin 3 and the inner layer part 4 are all constant except that the bending strength of the mold resin 3 is changed.

In FIG. 5, the determination result when the bending strength is 100 MPa to 150 MPa is "Acceptable", and the determination result when the bending strength is 90 MPa and the determination result when the bending strength is 160 MPa are both " "Not possible." From this, it can be seen that the appropriate bending strength is 100 MPa to 150 MPa. If the bending strength of the molded resin 3 is lower than the appropriate bending strength, the strength of the molded resin 3 will be insufficient and cracks will easily occur. Furthermore, if the bending strength of the molded resin 3 is greater than the appropriate bending strength, the flexibility of the molded resin 3 will be insufficient and cracks will likely occur. Therefore, the electromagnetic coil device 1 can suppress the occurrence of cracks because the bending strength of the molded resin 3 is 100 MPa or more and 150 MPa or less.

According to Embodiment 1, the electromagnetic coil device 1 is configured such that the inner layer portion 4, which is a resin having a lower elastic modulus than the mold resin 3, is disposed between the coil conductor 2 and the mold resin 3, so that the mold resin 3 The double structure with the inner layer portion 4 relieves impact stress. Further, the electromagnetic coil device 1 can obtain impact resistance due to the easily formed inner layer portion 4. Thereby, the electromagnetic coil device 1 can be manufactured easily, and the peeling of the mold resin 3 and the occurrence of cracks can be suppressed.

Embodiment 2.
In Embodiment 2, an example of a switch having the electromagnetic coil device 1 according to Embodiment 1 will be described. FIG. 6 is a sectional view of the switch according to the second embodiment. In Embodiment 2, the same components as in Embodiment 1 described above are given the same reference numerals, and configurations that are different from Embodiment 1 will be mainly explained.

The switch 10 according to the second embodiment is a vacuum circuit breaker that opens and closes an electric circuit in a vacuum valve that is in a high vacuum. The switch 10 has an opening/closing part 11 having a fixed electrode 13 and a movable electrode 14 as a pair of electrodes, a fixed shaft 15 connected to the fixed electrode 13, and a movable shaft 16 connected to the movable electrode 14. The fixed shaft 15 is fixed within the vacuum valve. Illustration of the vacuum valve is omitted.

The fixed electrode 13 is provided at the end of the fixed shaft 15. The position of the fixed electrode 13 within the vacuum valve is fixed. The movable electrode 14 moves axially within the vacuum valve. The axial direction is the direction of the movable shaft 16. In the following explanation, the state of the switch 10 when the fixed electrode 13 and the movable electrode 14 are in contact with each other is the closed state, and the state of the switch 10 when the fixed electrode 13 and the movable electrode 14 are apart from each other. is sometimes called the open state. FIG. 6 shows the switch 10 in the closed state.

The switch 10 has an operating mechanism 12 that operates the closing and opening of the opening/closing section 11. Putting in refers to moving the movable electrode 14 toward the fixed electrode 13 and bringing the movable electrode 14 into contact with the fixed electrode 13 . Opening refers to separating the movable electrode 14 that is in contact with the fixed electrode 13 from the fixed electrode 13.

The operating mechanism 12 includes an electromagnetic drive section 17 that drives the movable shaft 16 by electromagnetic force. The electromagnetic drive unit 17 includes an open-side fixed coil 21 , a closing-side fixed coil 22 , an opening-side moving coil 23 , and a closing-side moving coil 24 . Each of the open-side fixed coil 21, the closing-side fixed coil 22, the opening-side moving coil 23, and the closing-side moving coil 24 is the electromagnetic coil device 1. The opening side refers to the side in which the movable shaft 16 moves during the opening operation of the switch 10. The closing side refers to the side in which the movable shaft 16 moves during the closing operation of the switch 10. The electromagnetic drive unit 17 includes a drive circuit that allows current to flow through each of the open-side fixed coil 21 , the open-side moving coil 23 , the closing-side fixed coil 22 , and the closing-side moving coil 24 . Illustration of the drive circuit is omitted.

FIG. 7 is a cross-sectional view of the electromagnetic drive section included in the switch according to the second embodiment. The electromagnetic drive unit 17 includes a fixed plate 26 to which the open-side fixed coil 21 is fixed, a fixed plate 27 to which the closing-side fixed coil 22 is fixed, and the opening-side moving coil 23 and the closing-side moving coil 24 are fixed. It has a movable body 25. The open-side moving coil 23 and the closing-side moving coil 24 are fixed to a movable body 25 and are thus integrated with each other. The movable shaft 16 passes through the centers of the open-side fixed coil 21 , the open-side moving coil 23 , the closing-side fixed coil 22 , and the closing-side moving coil 24 . Furthermore, the movable shaft 16 passes through each of the movable body 25, the fixed plate 26, and the fixed plate 27.

The fixed plate 26 and the fixed plate 27 are not fixed to the movable shaft 16. The movable body 25 is fixed to the movable shaft 16. The open-side fixed coil 21 and the closing-side fixed coil 22 are fixed coils whose positions are fixed in the operating mechanism 12. The opening side moving coil 23 and the closing side moving coil 24 are moving coils that are fixed to the movable shaft 16 and movable in the operating mechanism 12.

The magnetic latch 18 is arranged on the closing side of the electromagnetic drive section 17. The magnetic latch 18 is a latch mechanism that utilizes the magnetic attraction force of a permanent magnet. The magnetic latch 18 includes a movable body 30 and a fixed plate 31, each of which has a permanent magnet attached thereto. The movable body 30 is fixed to the movable shaft 16 and is movable in the operating mechanism 12. The fixed plate 31 is not fixed to the movable shaft 16. The position of the fixed plate 31 in the operating mechanism 12 is fixed.

The contact pressure spring 32 is arranged between the magnetic latch 18 and the opening/closing part 11. The contact pressure spring 32 is a coil spring for pressing the movable electrode 14 against the fixed electrode 13. The contact pressure spring 32 is housed in the housing portion 33 . A fixing plate 34 is provided on the input side of the accommodating portion 33. The open end of the contact pressure spring 32 is in contact with the housing portion 33 . The end of the contact pressure spring 32 on the input side is in contact with the fixed plate 34 . The housing portion 33 is fixed to the movable shaft 16 and is movable in the operating mechanism 12 . The fixed plate 34 is not fixed to the movable shaft 16. The position of the fixed plate 34 in the operating mechanism 12 is fixed.

The release spring 28 is arranged on the open side of the electromagnetic drive section 17. The open end of the open spring 28 is in contact with the spring receiving plate 29 . The end of the release spring 28 on the input side is in contact with the fixed plate 26 . The elastic force of the opening spring 28 moves the movable shaft 16 toward the opening side. The spring receiving plate 29 is fixed to the movable shaft 16 and is movable in the operating mechanism 12.

When the switch 10 is in the closing state, the movable body 25 is in contact with the closing-side fixed coil 22. The release spring 28 is compressed between the fixed plate 26 and the spring receiving plate 29. The contact pressure spring 32 is compressed between the housing portion 33 and the fixed plate 34. When a current flows from the drive circuit to the closing fixed coil 22 and the closing moving coil 24 in the closing state, the closing fixed coil 22 and the closing moving coil 24 generate a magnetic field. The closing-side fixed coil 22 and the closing-side moving coil 24 generate electromagnetic forces that repel each other. The repulsive force between the closing-side fixed coil 22 and the closing-side moving coil 24 and the restoring force of the opening spring 28 become stronger than the magnetic attraction force of the magnetic latch 18, so that the opening spring 28 returns to its natural length from the contracted state. Restore to the state of. In this manner, the operating mechanism 12 moves the movable shaft 16 toward the opening side, thereby causing the switch 10 to perform an opening operation.

When the switch 10 is in the open state, the movable body 25 is in contact with the open-side fixed coil 21. When a current flows from the drive circuit to the open-side fixed coil 21 and the open-side moving coil 23 in the open state, the open-side fixed coil 21 and the open-side moving coil 23 generate a magnetic field. The open-side fixed coil 21 and the open-side moving coil 23 generate electromagnetic forces that repel each other. The opening spring 28 is compressed by the repulsive force between the opening-side fixed coil 21 and the opening-side moving coil 23 and the magnetic attraction force of the magnetic latch 18. In this manner, the operating mechanism 12 moves the movable shaft 16 to the closing side, thereby causing the switch 10 to perform a closing operation.

Each of the open-side fixed coil 21, the closing-side fixed coil 22, the opening-side moving coil 23, and the closing-side moving coil 24 has a double structure of a molded resin 3 and an inner layer portion 4. The switch 10 can alleviate impact stress caused by the collision of the open-side moving coil 23 with the open-side fixed coil 21 during the opening operation. In addition, the switch 10 can alleviate the impact stress caused by the collision of the closing-side moving coil 24 with the closing-side fixed coil 22 during the closing operation.

According to the second embodiment, the switch 10 can reduce the impact stress in the open side fixed coil 21, the closing side fixed coil 22, the opening side moving coil 23, and the closing side moving coil 24, Damage to the coil 21, the closing-side fixed coil 22, the opening-side moving coil 23, and the closing-side moving coil 24 can be reduced. Thereby, it is possible to obtain a highly reliable switch 10 with less damage.

The configurations shown in the embodiments above are examples of the contents of the present disclosure. The configuration of each embodiment can be combined with other known techniques. The configurations of each embodiment may be combined as appropriate. It is possible to omit or change a part of the configuration of each embodiment without departing from the gist of the present disclosure.

1 Electromagnetic coil device, 2 Coil conductor, 3 Molded resin, 4 Inner layer, 5 Current terminal, 6 Lead wire, 7 First surface, 8 Second surface, 10 Switch, 11 Opening/closing part, 12 Operating mechanism, 13 Fixed electrode , 14 movable electrode, 15 fixed axis, 16 movable axis, 17 electromagnetic drive unit, 18 magnetic latch, 21 open side fixed coil, 22 closing side fixed coil, 23 opening side moving coil, 24 closing side moving coil, 25, 30 movable body, 26, 27, 31, 34 fixing plate, 28 opening spring, 29 spring receiving plate, 32 contact pressure spring, 33 housing section.

Claims (5)

a coil conductor;
a molded resin covering the coil conductor;
an inner layer portion that is disposed between the coil conductor and the mold resin and is a resin having a lower elastic modulus than the mold resin ;
The inner layer portion has a first surface in contact with the coil conductor, and a second surface that is opposite to the first surface and in contact with the mold resin,
The thickness of the portion of the mold resin that is in contact with the second surface is 10 to 20 times the thickness of the inner layer between the first surface and the second surface. Electromagnetic coil device. The electromagnetic coil device according to claim 1, wherein the inner layer has an elastic modulus of 0.1 GPa or more and 4.0 GPa or less. The electromagnetic coil device according to claim 1, wherein the inner layer has a thickness of 0.5 mm or more and 1.0 mm or less. The electromagnetic coil device according to claim 1, wherein the bending strength of the mold resin is 100 MPa or more and 150 MPa or less. An opening/closing part having a pair of electrodes, a fixed electrode and a movable electrode;
a movable shaft connected to the movable electrode;
an operating mechanism that has a fixed coil and a movable coil fixed to the movable shaft, and operates to close and open the opening/closing part,
Each of the fixed coil and the movable coil is
a coil conductor;
a molded resin covering the coil conductor;
an inner layer portion that is disposed between the coil conductor and the mold resin and is a resin having a lower elastic modulus than the mold resin ;
The inner layer portion has a first surface in contact with the coil conductor, and a second surface that is opposite to the first surface and in contact with the mold resin,
The thickness of the portion of the mold resin that is in contact with the second surface is 10 to 20 times the thickness of the inner layer between the first surface and the second surface. switch.

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