JPWO2020084829A1 - Manufacturing method of electromagnet, electromagnetic switch, electromagnet, and manufacturing method of electromagnetic switch - Google Patents

Abstract

The electromagnet (10) has a movable iron core (20), a fixed iron core (30) arranged to face the movable iron core (20), and a drive coil (70) wound around the fixed iron core (30). One of the electromagnets, the movable core (20) or the fixed core (30), is a single plate of austenitic stainless steel on the surface facing the other core, and is a JIS standard 2B material or a JIS standard. The spacer (22) is provided by processing a thin plate which is a 2D material of the above, and the spacer (22) and the iron core (20, 30) are provided on at least one of the spacer (22) or the iron core (20, 30), and the other On the other hand, they are welded and fixed to each other by a welded portion (Y) having a convex shape.

Description

The present application relates to an electromagnet, an electromagnetic switch, and a method for manufacturing an electromagnet.

In a conventional electromagnet, a movable iron core is attracted to a fixed core by energizing an electric current, and both cores are separated by releasing the energization. In particular, in an electromagnet driven by a direct current drive or an electromagnet driven by a rectified alternating current, residual magnetization may occur in the iron core, and a state may occur in which the two iron cores are not separated even when the energization is released. In order to avoid this, an example is disclosed in which a thin plate of a non-magnetic metal is bonded to at least one contact surface of a movable iron core or a fixed iron core by brazing as a residual magnetic prevention spacer (see, for example, Patent Document 1).

Jitsukaisho 58-46412

In the electromagnet disclosed in Patent Document 1, when the current capacity of the electric circuit to be opened / closed increases, the contact point of the electric circuit also becomes large, and the opening / closing force of the electromagnet also increases. To increase the opening and closing force of the electromagnet, the iron core should be increased, but when brazing the residual magnetism prevention spacer, the iron core needs to be heated until the temperature of the iron core exceeds the melting point of the brazing material. There is a problem that the heating time becomes longer and the productivity deteriorates as the size increases.

Further, if silver wax having a low melting point is used to shorten the heating time, there is a problem that the price of the brazing material itself is high, which contributes to an increase in the manufacturing cost of the product.

The present application discloses a technique for solving the above-mentioned problems, and an object of the present application is to provide an electromagnet, an electromagnetic switch, and a method for manufacturing an electromagnet, which can be produced with high productivity and at low cost. To do.

The electromagnet disclosed in the present application is
Movable iron core and
A fixed iron core arranged to face the movable iron core and
An electromagnet having a drive coil wound around the fixed iron core.
One of the movable core or the fixed core is
A spacer made of a thin plate, which is a single plate of austenitic stainless steel and is a JIS standard 2B material or a JIS standard 2D material, is provided on the surface facing the other iron core.
The spacer and the iron core are provided on at least one of the spacer or the iron core, and are welded and fixed to each other by a welded portion having a convex shape with respect to the other.

Further, the electromagnetic switch disclosed in the present application is:
With the electromagnet
A fixed contact integrally molded with the fixed iron core,
It is provided with a movable contact integrally molded with the movable iron core, which is brought into contact with and separated from the fixed contact in conjunction with the drive of the movable iron core.

Further, the method for manufacturing an electromagnet disclosed in the present application is as follows.
The spacer or the protrusion provided on at least one of the iron cores is brought into contact with the other, and the spacer and the iron core are sandwiched between a pair of electrodes and pressurized, and electricity is applied between the electrodes to form the welded portion. It has a welding process to be performed.

According to the method for manufacturing an electromagnet, an electromagnetic switch, and an electromagnet disclosed in the present application, a non-magnetic thin plate spacer or an iron core that prevents magnetism remaining in the fixed iron core and the movable iron core after the energization of the electromagnet is stopped. Since a plurality of protrusions are provided on at least one of the protrusions and an electric current is passed through the protrusions to weld the spacer and the iron core at one time, a significant reduction in the time required for the joining process between the iron core and the spacer is expected and the productivity is high.

Further, since an auxiliary material for joining such as silver wax is not required, the cost of joining can be reduced.

It is sectional drawing of the electromagnetic switch according to Embodiment 1. FIG. It is sectional drawing of the electromagnet by Embodiment 1. FIG. It is a figure which looked at the movable iron core by Embodiment 1 from the spacer side. It is a top view of the spacer before welding according to Embodiment 1, and is the cross-sectional view of the main part thereof. It is a two-sided view of the fixed iron core according to the second embodiment. It is a figure which looked at the fixed iron core by Embodiment 3 from the spacer side. It is a figure which looked at the fixed iron core by Embodiment 4 from the spacer side. It is a two-sided view which shows the modification of the movable iron core by Embodiment 2. It is a figure which shows the arrangement example of another protrusion by Embodiment 2. FIG. It is a figure which shows the procedure of positioning a movable iron core and a spacer before welding by using the positioning jig according to Embodiment 5. It is a flow chart which shows the process of welding a spacer and a movable iron core by Embodiment 5. It is a figure which shows the dimensional relationship of the positioning jig and a spacer by Embodiment 5, and is the figure which shows the state after the positioning completion and before welding. It is a figure which shows the state which the energization for welding by Embodiment 5 is finished, welding is completed, but the electrode is still pressurizing. It is a figure which shows another example of the positioning jig according to Embodiment 5.

Embodiment 1.
Hereinafter, the method for manufacturing the electromagnet, the electromagnetic switch, and the electromagnet according to the first embodiment will be described with reference to the drawings.

FIG. 1 is a cross-sectional view of the electromagnetic switch 100.
The electromagnetic switch 100 includes an electromagnet 10, a fixed contact 40, and a movable contact 50.
The electromagnetic switch 100 opens and closes the movable contact 50 with respect to the fixed contact 40 by the operation of the electromagnet 10.

FIG. 2 is a cross-sectional view of the electromagnet 10.
The electromagnet 10 is wound around a movable core 20, fixed cores 30a and 30b, and fixed cores 30a and 30b, and drives the movable core 20 so as to be detachable from the fixed cores 30a and 30b. And. In the following description, the term “fixed core 30” refers to both the fixed core 30a and the fixed core 30b, and similarly, the term drive coil 70 refers to both the drive coil 70a and the drive coil 70b.

Spacers 22a and 22b are mounted on the surface of the movable core 20 facing the fixed core 30 to prevent magnetism remaining in the fixed core 30 and the movable core 20 after the energization of the electromagnet 10 is stopped. In the following description, the term spacer 22 simply refers to both the spacer 22a and the spacer 22b. The fixed iron core 30 is a set of two with the drive coil 70 attached, and is fixed to the base plate 33.

When a current is applied to the drive coils 70, magnetic fields in opposite directions are generated in the two drive coils 70. That is, when the drive coil 70a mounted on the left fixed core 30a generates a magnetic field on the fixed core 30a upward on the paper surface, the drive coil 70b mounted on the right fixed core 30b faces downward on the paper surface 30b. Generates a magnetic field of.

Then, the magnetic flux generated upward in the fixed core 30a on the left side passes through the spacer 22a installed on the left side of the movable core 20 and reaches the movable core 20, and the magnetic flux passes through the inside of the movable core 20 from the left side to the right side. It flows toward. The magnetic flux that reaches the right side of the movable iron core 20 passes through the spacer 22b and reaches the fixed iron core 30b on the right side, and the magnetic flux flows from the top to the bottom of the fixed iron core 30b on the right side.

Then, the magnetic flux reaching the lower part of the fixed iron core 30b on the right side flows to the right side of the base plate 33, which is also made of a magnetic material, and the magnetic flux flows from the right side to the left side of the base plate 33. Then, the magnetic flux reaching the left side of the base plate 33 flows to the lower part of the fixed iron core 30a and returns to the original state. When such a magnetic path is formed, the movable iron core 20 is attracted to the fixed iron core 30.
Then, as shown in FIG. 1, the movable contact 50 integrally molded or held via the movable iron core 20 and the resin molded product 25 (insulator) is interlocked with the drive of the movable iron core 20 and the upper housing 55 (insulation). The electric circuit is closed by coming into contact with the fixed contact 40 fixed to the object).

After that, when the current of the drive coil 70 is cut off, the magnetic flux generated from the drive coil 70 disappears. Here, when there is no air gap between the movable core 20 and the fixed core 30, residual magnetism is generated in both cores due to the coercive force of the materials of the movable core 20 and the fixed core 30, and the resin molded product 25 and the resin molded product 25 The repulsive force of the spring 27 provided between the lower housing 34 and the lower housing 34 cannot overcome the magnetic attraction force remaining in the fixed iron core 30 and the movable iron core 20, and the opening operation cannot be performed.

On the other hand, by providing the spacer 22 for preventing the residual magnetism of the non-magnetic material as in the present application, the portion where the spacer 22 exists is regarded as equivalent to the air gap on the magnetic circuit. A reverse magnetic field is applied to both iron cores beyond the above, and the effect that the residual magnetic flux becomes almost zero can be obtained.

Then, the spring 27 integrated with the movable iron core 20 pushes up the movable iron core 20 that has lost the suction force, so that the movable iron core 20 and the movable contact 50 integrated via the resin molded product 25 are transferred from the fixed contact 40. It will be separated and the electric circuit will be opened.

In this way, by turning on / off the current to the drive coil 70, the movable contact 50 is opened and closed through the movement of the movable iron core 20, and the electric circuit is opened and closed.

FIG. 3 is a view of the movable iron core 20 viewed from the spacer 22 side, and shows a state in which the spacer 22 is welded and fixed to the movable iron core 20.
The spacer 22 is made of a non-magnetic metal material and is cut out from, for example, a plate material. A total of two rectangular spacers 22 are welded and fixed to both ends of the movable iron core 20 in the longitudinal direction on the surface of the movable iron core 20 facing the fixed iron core 30.

A thin plate is used as the spacer 22, but more preferably, a thin plate of a non-magnetic stainless steel material having good compatibility with the iron-based material of the movable iron core in welding, particularly an austenitic stainless steel material such as SUS304 (STAINLESS USED STEEL) is used. , It is better to use the one processed into a rectangular shape by press punching.

In press working, burrs generally occur, and if the burrs are large, the burrs will peel off due to the impact of the opening and closing operation after the product is made, and will be caught between the movable iron core and the fixed iron core as foreign matter, and as an electromagnet. It may interfere with the operation. Therefore, the half-pulling flat punching method is used as a press working method that does not generate burrs. Further, as a processing method other than press processing, for example, laser processing or the like can be used.

Here, the following points are important as the functions of the spacer 22. That is, not only is the non-magnetic material necessary for the electromagnet 10 to open normally, but also the impact when the movable iron core 20 and the fixed iron core 30 collide with each other during the closing operation of the electromagnet 10 is repeated. However, it has enough strength to prevent it from peeling off from the movable iron core 20.

As shown in FIG. 3, in order to secure the joint strength, the spacers 22 are formed by welded portions Y having a circular shape having a diameter of about 3 mm to 5 mm and a convex shape in the direction of the movable iron core 20 at six places per sheet. It is welded and fixed to the movable iron core 20. As for the arrangement of the six welds Y, four are arranged near the corners of the spacer 22, and the remaining two are at the midpoints of the two welds Y provided at both ends of the long side of the spacer 22. Have been placed.

When the movable core 20 and the fixed core 30 are closed, the spacer 22 arranged between the movable core 20 and the fixed core 30 receives an impact due to the collision between the movable core 20 and the fixed core 30. However, as described above, by arranging a large number of welded portions Y, the impact is dispersed in the six welded portions Y, and the number of times of opening and closing is increased from 5 million to 10 million by long-term use of the electromagnetic switch 100. Even in such a case, consideration is given so that the spacer 22 does not peel off from the movable iron core 20 due to fatigue fracture in the vicinity of the welded portion Y.

According to our research, regarding the strength of the welded portion Y, when the strength difference between the portion once melted by welding and the original portion is large, the strength changes due to the impact during the closing operation of the electromagnet 10. It has been confirmed that stress is concentrated on the surface and fatigue fracture is likely to occur.

That is, even with the SUS304 material, if the hardness is tempered to JIS (Japanese Industrial Standards) standard 1 / 2H material or the material to be tempered to a hardness higher than that, the opening / closing frequency is 5 million times or less and the welded portion Y Peeling of the spacer 22 due to fatigue failure was confirmed.

On the other hand, it was confirmed that when a JIS standard 2B material whose hardness was not tempered was used, it could withstand an opening / closing test of 5 to 10 million times. That is, a JIS standard 2D material or a hot rolled material having a hardness equal to or lower than that of a 2B material has a high fatigue strength and is equal to or higher than a JIS standard 1 / 4H tempered material. It was found that the material tempered to hardness was inferior in fatigue strength and was not suitable for this application.

On the other hand, regarding the function as a non-magnetic material, austenitic stainless steel materials such as SUS304 material are non-magnetic materials because the crystal structure changes from austenite to martensite due to cold working and the arrangement of impurities changes. It is known that it changes to a magnetic material although it is weak.

If the spacer 22 is magnetic, the effect of suppressing the residual magnetization of the movable iron core 20 and the fixed iron core 30, which is the original purpose, is halved, which may hinder the opening operation of the movable iron core 20. In that sense as well, it should be avoided to use a tempered material that increases the hardness of SUS304.

Similarly, austenitic stainless steel is made from non-magnetic materials because the crystal structure changes from austenite to martensite and the arrangement of impurities changes when the part once melted by welding is cooled and returns to a solid. It is known that although it is weak, it changes to a magnetic material. Therefore, it is desirable that the welded portion is as small as possible, and as in the first embodiment, by providing the small welded portions Y at a plurality of dispersed portions, the welding strength as a whole and the magnetic characteristics of the non-magnetic material can be improved. It is possible to achieve both.

The movable iron core 20 in which the spacer 22 has been welded is subjected to rust-preventive plating because rust is generated as it is. Zn (zinc) plating is desirable if only the movable iron core 20 is in the state, but since the spacer 22 made of SUS is integrated, Zn plating is not well generated on the surface of SUS. On the other hand, first, a method of welding the spacer 22 of SUS to the movable iron core 20 plated with Zn is conceivable, but it is known that the welding strength is lowered due to the influence of plating.

Therefore, after welding the spacer 22 to the movable iron core 20, Ni (nickel) strike plating treatment is performed, and then Zn chromate plating treatment is performed, so that the surface of the spacer 22 made of SUS is utilized while utilizing the rust preventive function of Zn plating. Since plating is also applied to the surface, good plating processing is possible.

FIG. 4A is a plan view of the spacer 22 before welding.
4B is a cross-sectional view of a main part of FIG. 4A. FIG. 4A is a diagram showing an arrangement of protrusions 24 before welding provided on the spacer 22. FIG. 4B is a diagram showing a cross section of the protrusion 24 and the portion AA in the vicinity thereof.
The protrusion 24 is provided at the same position as the arrangement of the welded portion Y. As can be seen from the cross-sectional view taken along the line AA showing the configuration of the protrusion 24, the protrusion 24 has a concave portion formed on the left side portion of the plate and a convex portion formed on the right side portion of the plate by the length H in the range of φD. All of them are formed in a spherical shape having a constant radius.

This spherical shape is formed by, for example, in a pressing device, a punch having a hemispherical protrusion and a die having a hemispherical recess shape sandwich a plate of SUS304 and push the punch into the die. As an example of these shapes, it was confirmed that φD is preferably about 2 mm to 5 mm and H is preferably about 0.3 mm to 1.5 mm in a plate thickness t in the range of 0.3 mm to 1.5 mm.

Here, the welding method between the spacer 22 and the movable iron core 20 is such that the spacer 22 and the movable iron core 20 are sandwiched between a pair of flat plate-shaped electrodes, and the protrusion 24 and the movable iron core 20 are in contact with each other. Pressurize. Further, by applying a large current between the electrodes via the protrusion 24, heat is concentrated on the tip of the protrusion 24, and the tip of the protrusion 24 and a part of the movable iron core 20 in contact with the protrusion 24 are melted. Both are welded and joined.

The number of times of energization can be one regardless of the number of protrusions 24. The pressing force at this time depends on the plate thickness, but is in the range of 0.2 kN to 2 kN per protrusion 24. The energizing current is 2 kA to 5 kA per protrusion. Further, the energizing time is in the range of 15 msec to 60 msec.

It has been confirmed that when a large current is passed in a design in which the distances between the protrusions 24 are short, the melted portions are pulled by each other and move due to the Lorentz force, and a long protrusion-like portion is formed. This part does not affect the welding strength, and in the worst case, it is removed by the impact of opening and closing and becomes a foreign substance. In the configuration of the first embodiment, for example, if this foreign matter is caught between the spacer 22 and the fixed iron core 30, the attractive force between the iron cores at the time of closing the pole is reduced, which hinders the opening / closing operation of the electromagnet 10. There is a fear. Therefore, in order to prevent the above-mentioned long protrusion-like portion from being formed, it is desirable that the distance between the protrusions 24 is 10 mm or more.

Further, in general, a resistance welding method in which welding is performed without providing protrusions is often used, but it is necessary to perform welding by sandwiching welded portions one by one using a thin electrode having a diameter of about several mm. When applied to the case where a plurality of welded portions Y are provided as in this case, the process of first aligning the welded portions and then sandwiching the welded portions and energizing the welded portions is repeated a plurality of times as many times as the number of the welded portions. As a result, it takes a long time to perform all welding, and when welding the second and subsequent welds, the current circulates in the previously welded weld and the current in the part to be welded decreases, resulting in insufficient welding. There is a risk of becoming.

On the other hand, according to the welding method shown in the first embodiment, positioning of the electrodes becomes unnecessary by energizing the spacer 22 and the movable iron core 20 by sandwiching the spacer 22 and the movable iron core 20 by a pair of flat plate-shaped electrodes larger than the spacer 22. .. Further, since a method of pressurizing the protrusion 24 and the movable iron core 20 in contact with each other and energizing a large current between the movable iron core 20 and the spacer 22 main body via the protrusion 24 is adopted, one energization is required. It becomes possible to generate a plurality of welded portions Y, which is advantageous in terms of productivity.

In the first embodiment, a spherical shape is exemplified as the shape of the protrusion 24, but the shape is not limited to this, and for example, a conical shape may be used. Further, although the shape of the back side of the protrusion 24 and the shape of the front side of the protrusion 24 are both spherical, they do not necessarily have to be the same shape. For example, the front surface is spherical and the back surface is conical. There is no problem even if it is a combination.

As a precaution when forming the protrusions 24 on the spacer 22, it is desirable that the shapes and heights of the plurality of protrusions 24 are the same. If the heights of the protrusions 24 are not uniform, one protrusion 24 is in contact with the movable iron core 20, but the other protrusions 24 are not in contact with each other, and the non-contact protrusions 24 cannot be welded. This is because there is a risk.

There are several types of power supplies used for welding, but it is particularly desirable to use a capacitor-type power supply that controls a constant current by inverter control when discharging charges after storing charges in a capacitor. With this power supply, a large current can be passed in a short time, and the energy required for welding can be set to the minimum necessary, so that the generation of spattered foreign matter and the explosion during welding are suppressed. However, stable welding is possible.

Further, in the first embodiment, an example in which the protrusion 24 is provided on the spacer 22 side is shown, but it is not always necessary to provide the protrusion 24 on the spacer 22, and conversely, the protrusion may be provided on the movable iron core 20 side. Even in that case, the welding procedure is as described above and does not change.

According to the method for manufacturing the electromagnet 10, the electromagnetic switch 100, and the electromagnet according to the first embodiment, a non-magnetic thin plate that prevents magnetism remaining in the fixed iron core 30 and the movable iron core 20 after the energization of the electromagnet 10 is stopped. Since a plurality of protrusions 24 are provided on the spacer 22 and the protrusions 24 can be welded to the movable iron core 20 at one time, a significant reduction in the joining process time is expected and the productivity is high.

Further, since an auxiliary material for joining such as silver wax is not required, the cost of joining can be reduced.

Embodiment 2.
Hereinafter, the method for manufacturing the electromagnet, the electromagnetic switch, and the electromagnet according to the second embodiment will be described with reference to the drawings, focusing on the parts different from the first embodiment.
FIG. 5A is a view of the fixed iron core 230 as viewed from the spacer 232 side.
FIG. 5B is a side view of the fixed iron core 230.

In the first embodiment, the spacer 22 is welded to the movable iron core 20, but in the present embodiment, the spacer 232 is welded to the fixed iron core 230. As described above, it goes without saying that the spacer 232 has the same effect as that of the first embodiment even if it is welded and fixed to the fixed iron core 230 side instead of the movable iron core 20. As shown in FIGS. 5A and 5B, when the spacer 232 is welded to the iron core (regardless of whether it is movable or fixed) via a protrusion, a convex shape remains in the welded portion Y, and a convex shape remains between the spacer 232 and the iron core. , It is inevitable that a minute gap d remains. This also applies to the welded portion Y of the first embodiment.

In our experiment, it was found that the thicker the spacer 232, the larger the gap d. It was confirmed that when the gap d becomes large, the spacer 232 tends to be easily peeled off in the opening / closing repeated test of the electromagnet 10. Therefore, it is desirable to make the gap d as small as possible, and it is desirable to make it 0.2 mm or less, more preferably 0.1 mm or less.

In the second embodiment, the number of welded portions Y is five. For the spacer 232 having a rectangular shape and a relatively small difference between the long side and the short side, it is effective to provide the welded portions Y diagonally with the four corners of the spacer 232. Further, for those having a small difference between the long side and the short side, welded portions Y may be provided only at four points at the four corners.

According to the method for manufacturing the electromagnet 10, the electromagnetic switch 100, and the electromagnet according to the second embodiment, a non-magnetic thin plate that prevents magnetism remaining in the fixed iron core 230 and the movable iron core 20 after the energization of the electromagnet 10 is stopped. Since a plurality of protrusions 24 are provided on the spacer 232 and the protrusions 24 can be welded to the fixed iron core 230 at one time, a significant reduction in the joining process time is expected.

8A and 8B are two views showing a modified example of the movable iron core. FIG. 8A is a view of the fixed iron core 230B viewed from the side where the spacer is welded, and FIG. 8B is a side view of the fixed iron core 230B.

Although an example in which the protrusion 24 is provided on the spacer has been shown so far, the protrusion 24B may be provided on the side of the fixed iron core 230B as shown in FIGS. 8A and 8B. Generally, since the spacer is a thin plate, it is easier to process protrusions than an iron core. However, at the time of welding, if the melting condition on the iron core side is poor, it may be advantageous to provide a protrusion on the iron core side. Needless to say, even if a protrusion is provided on the iron core side, welding can be performed by adjusting the welding conditions.

9A, 9B, and 9C are diagrams showing examples of arrangement of other protrusions.
FIG. 9A is a plan view of the spacer 232C.
FIG. 9C is a view of the fixed iron core 230C as viewed from the side where the spacer 232C is welded.
FIG. 9B is a diagram showing a state in which the spacer 232C is welded to the fixed iron core 230C.
As shown in FIGS. 9A, 9B, and 9C, the same welding can be performed even if the protrusions 24C and 24B are provided on both the spacer 232C and the fixed iron core 230C.

In this example, three protrusions 24C1 out of a total of six protrusions are provided on the spacer 232C, and the remaining three protrusions 24C2 are arranged on the fixed iron core 230C side at positions that are the vertices of a triangle, respectively, and after welding. Has a rectangular arrangement in which all the welded portions Y are arranged. By changing the heights of the protrusions 24C1 and 24C2, the heights of the protrusions 24C1 and 24C2 are supported at three points, whichever is higher, and the stability of the spacer 232C before welding can be expected to be improved.

Embodiment 3.
Hereinafter, the method for manufacturing the electromagnet, the electromagnetic switch, and the electromagnet according to the third embodiment will be described with reference to the drawings, focusing on the parts different from the first and second embodiments.
FIG. 6 is a view of the fixed iron core 330 as viewed from the spacer 332 side.
The outer peripheral shape of the contact surface of the fixed iron core 330 is circular, and the spacer 332 is configured to have a slightly smaller circular shape having the same center point O as the outer circumference of the fixed iron core 330.

Further, the welded portions Y are provided at three positions that are the vertices of the equilateral triangles centered on the center point O. If the number of welded portions Y = the number of protrusions before welding is set to three, the contact between the fixed iron core 330 and the spacer 332 is stable even if the height of the protrusions 24 varies, so that each welded portion Y The contact resistance is stable, and stable energization and welding are possible. Even if the outer peripheral shape of the contact surface of the fixed iron core is quadrangular and the shape of the spacer is circular, the same effect is obtained.

Embodiment 4.
Hereinafter, the method for manufacturing the electromagnet, the electromagnetic switch, and the electromagnet according to the fourth embodiment will be described with reference to the parts different from the first to third embodiments.
FIG. 7 is a view of the fixed iron core 430 viewed from the spacer 432 side.
The outer peripheral shape of the contact surface of the fixed iron core 430 is rectangular, and the long side is considerably longer than the short side.
Welded portions Y along the edges of the long sides of each are provided at three locations. Further, two welded portions Y adjacent to the edge of one long side and two welded portions Y on the same side in the longitudinal direction as the two welded portions Y on the other long side edge. Another weld Y is provided, which is arranged on the intersection of diagonal lines of a square having a total of four welds Y as vertices. Therefore, in FIG. 7, the number of welded portions Y arranged on the intersections of the diagonal lines is two, and the total number of welded portions Y is eight.

According to this configuration, even when a rectangular spacer 432 having a large aspect ratio is adopted, the welding strength of the fixed iron core 430 and the spacer 432 is not impaired, and the spacer 432 can be reliably fixed.

Embodiment 5.
Hereinafter, the method for manufacturing an electromagnet according to the fifth embodiment will be described with reference to the drawings.
FIG. 10 is a diagram showing a procedure for positioning the movable iron core 20 and the spacer 22 made of SUS before welding by using the positioning jig 500.
FIG. 11 is a flow chart showing a process of welding the spacer 22 and the movable iron core 20.

First, a positioning jig 500 having an opening 22k in which a portion where the spacer 22 is to be installed is hollowed out is placed on the welded surface 20s of the movable iron core 20 (step S001: positioning jig mounting step). Next, the two spacers 22 are fitted and arranged along the edge of the opening 22k. (Step S002: Spacer placement step). By arranging the spacers in this way, the position of the spacer 22 with respect to the movable iron core 20 can be accurately positioned.

FIG. 12 is a diagram showing the dimensional relationship between the positioning jig 500 and the spacer 22, and shows the state after the positioning is completed and before welding.
The spacer 22 is pressurized by the electrode 600, but is not yet energized.
FIG. 13 is a diagram showing a state in which energization for welding (step S003: welding step) is completed, welding is completed, but the electrode 600 is still pressurizing.

In FIGS. 12 and 13, the thickness of the portion of the spacer 22 excluding the conical protrusion 24B is hs, the height of the protrusion 24B provided on the spacer 22 before welding is ht, and the portion of the spacer 22 in contact with the spacer 22 of the positioning jig 500. Assuming that the thickness is hj, by setting the three dimensional relationships so that ht <hj ≦ hs, welding is performed while leaving a portion where the positioning jig 500 and the spacer 22 are in contact with each other before welding (hj-ht> 0). Later, it is possible to secure a gap (hs + d−hj ≧ 0) in which the positioning jig 500 and the electrode 600 do not come into contact with each other, or are not pressurized even if they come into contact with each other. As a result, the spacer 22 and the movable iron core 20 can be welded (step S003: welding step) with the positioning jig 500 installed, and the accuracy of the welding positions of both can be improved.

FIG. 14 is a diagram showing another example of the positioning jig.
The positioning jig 500B is obtained by cutting and opening both ends of the positioning jig 500 in the longitudinal direction at a portion including a part of the above-mentioned opening 22k. It is possible to improve the workability of installing the spacer 22 while maintaining the positioning accuracy of the spacer 22.

As described above, the protrusions may be provided on the fixed iron core side, or even when the protrusions are provided on both sides, the same effect can be obtained if the height of the protrusions is ht.

It is desirable to use an insulator for the positioning jigs 500 and 500B, and a resin such as glass epoxy or monomer cast nylon, or a material such as ceramic can be applied. In the present embodiment, the spacer is rectangular, but it goes without saying that other shapes such as the above-mentioned circular shape can be applied.

In each of the above embodiments, SUS304 is exemplified as the material of the spacers 22, 232, 332, and 432, but other austenitic stainless steel materials such as SUS300 series, which are not tempered to increase the hardness, are used. Needless to say, if there is, the same effect can be obtained.

Regarding the phenomenon that austenitic stainless steel is magnetized by processing, it is known that magnetization can be suppressed by increasing the nickel content in terms of materials, and although the material price rises, SUS305, which has a high nickel content, , SUS316 and the like can be selected to significantly reduce the magnetization due to processing.

Further, as the material of the iron core, an integral shape is exemplified, but it goes without saying that the same effect can be obtained by using an electromagnetic steel plate or a material obtained by laminating and integrating magnetic steel plates such as cold-rolled steel plates.

Although the present application describes various exemplary embodiments and examples, the various features, embodiments, and functions described in one or more embodiments are applications of a particular embodiment. It is not limited to, but can be applied to embodiments alone or in various combinations. Therefore, innumerable variations not illustrated are envisioned within the scope of the techniques disclosed in the present application. For example, it is assumed that at least one component is modified, added or omitted, and further, at least one component is extracted and combined with the components of other embodiments.

10 electromagnet, 20 movable iron core, 22,232,232C, 332,432 spacer, 22k opening, 24,24B, 24C1,24C2 protrusion, 25 resin molded product, 30,30a, 30b, 230, 230B, 330, 430 fixed Iron core, 33 base plate, 34 lower housing, 40 fixed contacts, 50 movable contacts, 55 upper housing, 70, 70a, 70b drive coil, 100 electromagnetic switch, 500, 500B positioning jig, 600 electrodes, O center point, Y welding Part, d gap.

This application is intended electromagnet, an electromagnetic switch, electrostatic method for producing a magnet, and to a manufacturing method of the electromagnetic switch.

In a conventional electromagnet, a movable iron core is attracted to a fixed core by energizing an electric current, and both cores are separated by releasing the energization. In particular, in an electromagnet driven by a direct current drive or an electromagnet driven by a rectified alternating current, residual magnetization may occur in the iron core, and a state may occur in which the two iron cores are not separated even when the energization is released. In order to avoid this, an example is disclosed in which a thin plate of a non-magnetic metal is bonded to at least one contact surface of a movable iron core or a fixed iron core by brazing as a residual magnetic prevention spacer (see, for example, Patent Document 1).

Jitsukaisho 58-46412

In the electromagnet disclosed in Patent Document 1, when the current capacity of the electric circuit to be opened / closed increases, the contact point of the electric circuit also becomes large, and the opening / closing force of the electromagnet also increases. To increase the opening and closing force of the electromagnet, the iron core should be increased, but when brazing the residual magnetism prevention spacer, the iron core needs to be heated until the temperature of the iron core exceeds the melting point of the brazing material. There is a problem that the heating time becomes longer and the productivity deteriorates as the size increases.

Further, if silver wax having a low melting point is used to shorten the heating time, there is a problem that the price of the brazing material itself is high, which contributes to an increase in the manufacturing cost of the product.

This application, which discloses a technique for solving the above problems, high productivity, and an electromagnet that can be produced at low cost, an electromagnetic switch, electrostatic method for producing a magnet, and the production of electromagnetic switch The purpose is to provide a method.

The electromagnet disclosed in the present application is
Movable iron core and
A fixed iron core arranged to face the movable iron core and
An electromagnet having a drive coil wound around the fixed iron core.
One of the movable core or the fixed core is
The other of the core and the surface facing a single plate austenitic stainless comprises a spacer obtained by processing thin plate having a 2 B material and a hardness of less comparable JIS standards including 2B material JIS standard,
The spacer and the iron core are provided on at least one of the spacer or the iron core, and are welded and fixed to each other by a welded portion having a convex shape with respect to the other.

Further, the electromagnetic switch disclosed in the present application is:
With the electromagnet
A fixed contact integrally molded with the fixed iron core,
It is provided with a movable contact integrally molded with the movable iron core, which is brought into contact with and separated from the fixed contact in conjunction with the drive of the movable iron core.

Further, the method for manufacturing an electromagnet disclosed in the present application is as follows.
The spacer or the convex protrusion provided on at least one of the iron cores is brought into contact with the other, and the spacer and the iron core are sandwiched between a pair of electrodes and pressurized, and electricity is applied between the electrodes. It has a welding process for forming the welded portion.
Further, the method for manufacturing an electromagnetic switch disclosed in the present application is as follows.
An electromagnet manufactured by using the method for manufacturing an electromagnet and
A fixed contact that is insulated and connected to the fixed iron core,
Manufacture an electromagnetic switch including a movable contact that is insulated and connected to the movable iron core that is brought into contact with and separated from the fixed contact in conjunction with the drive of the movable iron core.

Electromagnets disclosed in the present application, electromagnetic switch, electrostatic method for producing a magnet, and according to the manufacturing method of the electromagnetic switch, a non-magnetic to prevent the magnetism remaining in the fixed iron core and the movable core after stopping the energization of the electromagnet A plurality of protrusions are provided on at least one of the thin plate-shaped spacer or the iron core, and an electric current is passed through these protrusions to weld the spacer and the iron core at a time. Highly sexual.

Further, since an auxiliary material for joining such as silver wax is not required, the cost of joining can be reduced.

It is sectional drawing of the electromagnetic switch according to Embodiment 1. FIG. It is sectional drawing of the electromagnet by Embodiment 1. FIG. It is a figure which looked at the movable iron core by Embodiment 1 from the spacer side. It is a top view of the spacer before welding according to Embodiment 1, and is the cross-sectional view of the main part thereof. It is a two-sided view of the fixed iron core according to the second embodiment. It is a figure which looked at the fixed iron core by Embodiment 3 from the spacer side. It is a figure which looked at the fixed iron core by Embodiment 4 from the spacer side. It is a two-sided view which shows the modification of the movable iron core by Embodiment 2. It is a figure which shows the arrangement example of another protrusion by Embodiment 2. FIG. It is a figure which shows the procedure of positioning a movable iron core and a spacer before welding by using the positioning jig according to Embodiment 5. It is a flow chart which shows the process of welding a spacer and a movable iron core by Embodiment 5. It is a figure which shows the dimensional relationship of the positioning jig and a spacer by Embodiment 5, and is the figure which shows the state after the positioning completion and before welding. It is a figure which shows the state which the energization for welding by Embodiment 5 is finished, welding is completed, but the electrode is still pressurizing. It is a figure which shows another example of the positioning jig according to Embodiment 5.

Embodiment 1.
Hereinafter, the electromagnet according to the first embodiment, the electromagnetic switch, electrostatic method for producing a magnet, and a method of manufacturing the electromagnetic switch will be described with reference to FIG.

FIG. 1 is a cross-sectional view of the electromagnetic switch 100.
The electromagnetic switch 100 includes an electromagnet 10, a fixed contact 40, and a movable contact 50.
The electromagnetic switch 100 opens and closes the movable contact 50 with respect to the fixed contact 40 by the operation of the electromagnet 10.

FIG. 2 is a cross-sectional view of the electromagnet 10.
The electromagnet 10 is wound around a movable core 20, fixed cores 30a and 30b, and fixed cores 30a and 30b, and drives the movable core 20 so as to be detachable from the fixed cores 30a and 30b. And. In the following description, the term “fixed core 30” refers to both the fixed core 30a and the fixed core 30b, and similarly, the term drive coil 70 refers to both the drive coil 70a and the drive coil 70b.

Spacers 22a and 22b are mounted on the surface of the movable core 20 facing the fixed core 30 to prevent magnetism remaining in the fixed core 30 and the movable core 20 after the energization of the electromagnet 10 is stopped. In the following description, the term spacer 22 simply refers to both the spacer 22a and the spacer 22b. The fixed iron core 30 is a set of two with the drive coil 70 attached, and is fixed to the base plate 33.

When a current is applied to the drive coils 70, magnetic fields in opposite directions are generated in the two drive coils 70. That is, when the drive coil 70a mounted on the left fixed core 30a generates a magnetic field on the fixed core 30a upward on the paper surface, the drive coil 70b mounted on the right fixed core 30b faces downward on the paper surface 30b. Generates a magnetic field of.

Then, the magnetic flux generated upward in the fixed core 30a on the left side passes through the spacer 22a installed on the left side of the movable core 20 and reaches the movable core 20, and the magnetic flux passes through the inside of the movable core 20 from the left side to the right side. It flows toward. The magnetic flux that reaches the right side of the movable iron core 20 passes through the spacer 22b and reaches the fixed iron core 30b on the right side, and the magnetic flux flows from the top to the bottom of the fixed iron core 30b on the right side.

Then, the magnetic flux reaching the lower part of the fixed iron core 30b on the right side flows to the right side of the base plate 33, which is also made of a magnetic material, and the magnetic flux flows from the right side to the left side of the base plate 33. Then, the magnetic flux reaching the left side of the base plate 33 flows to the lower part of the fixed iron core 30a and returns to the original state. When such a magnetic path is formed, the movable iron core 20 is attracted to the fixed iron core 30.
Then, as shown in FIG. 1, the movable contact 50 integrally molded or held via the movable iron core 20 and the resin molded product 25 (insulator) is interlocked with the drive of the movable iron core 20 and the upper housing 55 (insulation). The electric circuit is closed by coming into contact with the fixed contact 40 fixed to the object).

After that, when the current of the drive coil 70 is cut off, the magnetic flux generated from the drive coil 70 disappears. Here, when there is no air gap between the movable core 20 and the fixed core 30, residual magnetism is generated in both cores due to the coercive force of the materials of the movable core 20 and the fixed core 30, and the resin molded product 25 and the resin molded product 25 The repulsive force of the spring 27 provided between the lower housing 34 and the lower housing 34 cannot overcome the magnetic attraction force remaining in the fixed iron core 30 and the movable iron core 20, and the opening operation cannot be performed.

On the other hand, by providing the spacer 22 for preventing the residual magnetism of the non-magnetic material as in the present application, the portion where the spacer 22 exists is regarded as equivalent to the air gap on the magnetic circuit. A reverse magnetic field is applied to both iron cores beyond the above, and the effect that the residual magnetic flux becomes almost zero can be obtained.

Then, the spring 27 integrated with the movable iron core 20 pushes up the movable iron core 20 that has lost the suction force, so that the movable iron core 20 and the movable contact 50 integrated via the resin molded product 25 are transferred from the fixed contact 40. It will be separated and the electric circuit will be opened.

In this way, by turning on / off the current to the drive coil 70, the movable contact 50 is opened and closed through the movement of the movable iron core 20, and the electric circuit is opened and closed.

FIG. 3 is a view of the movable iron core 20 viewed from the spacer 22 side, and shows a state in which the spacer 22 is welded and fixed to the movable iron core 20.
The spacer 22 is made of a non-magnetic metal material and is cut out from, for example, a plate material. A total of two rectangular spacers 22 are welded and fixed to both ends of the movable iron core 20 in the longitudinal direction on the surface of the movable iron core 20 facing the fixed iron core 30.

A thin plate is used as the spacer 22, but more preferably, a thin plate of a non-magnetic stainless steel material having good compatibility with the iron-based material of the movable iron core in welding, particularly an austenitic stainless steel material such as SUS304 (STAINLESS USED STEEL) is used. , It is better to use the one processed into a rectangular shape by press punching.

In press working, burrs generally occur, and if the burrs are large, the burrs will peel off due to the impact of the opening and closing operation after the product is made, and will be caught between the movable iron core and the fixed iron core as foreign matter, and as an electromagnet. It may interfere with the operation. Therefore, the half-pulling flat punching method is used as a press working method that does not generate burrs. Further, as a processing method other than press processing, for example, laser processing or the like can be used.

Here, the following points are important as the functions of the spacer 22. That is, not only is the non-magnetic material necessary for the electromagnet 10 to open normally, but also the impact when the movable iron core 20 and the fixed iron core 30 collide with each other during the closing operation of the electromagnet 10 is repeated. However, it has enough strength to prevent it from peeling off from the movable iron core 20.

As shown in FIG. 3, in order to secure the joint strength, the spacers 22 are formed by welded portions Y having a circular shape having a diameter of about 3 mm to 5 mm and a convex shape in the direction of the movable iron core 20 at six places per sheet. It is welded and fixed to the movable iron core 20. As for the arrangement of the six welds Y, four are arranged near the corners of the spacer 22, and the remaining two are at the midpoints of the two welds Y provided at both ends of the long side of the spacer 22. Have been placed.

When the movable core 20 and the fixed core 30 are closed, the spacer 22 arranged between the movable core 20 and the fixed core 30 receives an impact due to the collision between the movable core 20 and the fixed core 30. However, as described above, by arranging a large number of welded portions Y, the impact is dispersed in the six welded portions Y, and the number of times of opening and closing is increased from 5 million to 10 million by long-term use of the electromagnetic switch 100. Even in such a case, consideration is given so that the spacer 22 does not peel off from the movable iron core 20 due to fatigue fracture in the vicinity of the welded portion Y.

According to our research, regarding the strength of the welded portion Y, when the strength difference between the portion once melted by welding and the original portion is large, the strength changes due to the impact during the closing operation of the electromagnet 10. It has been confirmed that stress is concentrated on the surface and fatigue fracture is likely to occur.

That is, even with the SUS304 material, if the hardness is tempered to JIS (Japanese Industrial Standards) standard 1 / 2H material or the material to be tempered to a hardness higher than that, the opening / closing frequency is 5 million times or less and the welded portion Y Peeling of the spacer 22 due to fatigue failure was confirmed.

On the other hand, it was confirmed that when a JIS standard 2B material whose hardness was not tempered was used, it could withstand an opening / closing test of 5 to 10 million times. That is, a JIS standard 2D material or a hot rolled material having a hardness equal to or lower than that of a 2B material has a high fatigue strength and is equal to or higher than a JIS standard 1 / 4H tempered material. It was found that the material tempered to hardness was inferior in fatigue strength and was not suitable for this application.

On the other hand, regarding the function as a non-magnetic material, austenitic stainless steel materials such as SUS304 material are non-magnetic materials because the crystal structure changes from austenite to martensite due to cold working and the arrangement of impurities changes. It is known that it changes to a magnetic material although it is weak.

If the spacer 22 is magnetic, the effect of suppressing the residual magnetization of the movable iron core 20 and the fixed iron core 30, which is the original purpose, is halved, which may hinder the opening operation of the movable iron core 20. In that sense as well, it should be avoided to use a tempered material that increases the hardness of SUS304.

Similarly, austenitic stainless steel is made from non-magnetic materials because the crystal structure changes from austenite to martensite and the arrangement of impurities changes when the part once melted by welding is cooled and returns to a solid. It is known that although it is weak, it changes to a magnetic material. Therefore, it is desirable that the welded portion is as small as possible, and as in the first embodiment, by providing the small welded portions Y at a plurality of dispersed portions, the welding strength as a whole and the magnetic characteristics of the non-magnetic material can be improved. It is possible to achieve both.

The movable iron core 20 in which the spacer 22 has been welded is subjected to rust-preventive plating because rust is generated as it is. Zn (zinc) plating is desirable if only the movable iron core 20 is in the state, but since the spacer 22 made of SUS is integrated, Zn plating is not well generated on the surface of SUS. On the other hand, first, a method of welding the spacer 22 of SUS to the movable iron core 20 plated with Zn is conceivable, but it is known that the welding strength is lowered due to the influence of plating.

Therefore, after welding the spacer 22 to the movable iron core 20, Ni (nickel) strike plating treatment is performed, and then Zn chromate plating treatment is performed, so that the surface of the spacer 22 made of SUS is utilized while utilizing the rust preventive function of Zn plating. Since plating is also applied to the surface, good plating processing is possible.

FIG. 4A is a plan view of the spacer 22 before welding.
4B is a cross-sectional view of a main part of FIG. 4A. FIG. 4A is a diagram showing an arrangement of protrusions 24 before welding provided on the spacer 22. FIG. 4B is a diagram showing a cross section of the protrusion 24 and the portion AA in the vicinity thereof.
The protrusion 24 is provided at the same position as the arrangement of the welded portion Y. As can be seen from the cross-sectional view taken along the line AA showing the configuration of the protrusion 24, the protrusion 24 has a concave portion formed on the left side portion of the plate and a convex portion formed on the right side portion of the plate by the length H in the range of φD. All of them are formed in a spherical shape having a constant radius.

This spherical shape is formed by, for example, in a pressing device, a punch having a hemispherical protrusion and a die having a hemispherical recess shape sandwich a plate of SUS304 and push the punch into the die. As an example of these shapes, it was confirmed that φD is preferably about 2 mm to 5 mm and H is preferably about 0.3 mm to 1.5 mm in a plate thickness t in the range of 0.3 mm to 1.5 mm.

Here, the welding method between the spacer 22 and the movable iron core 20 is such that the spacer 22 and the movable iron core 20 are sandwiched between a pair of flat plate-shaped electrodes, and the protrusion 24 and the movable iron core 20 are in contact with each other. Pressurize. Further, by applying a large current between the electrodes via the protrusion 24, heat is concentrated on the tip of the protrusion 24, and the tip of the protrusion 24 and a part of the movable iron core 20 in contact with the protrusion 24 are melted. Both are welded and joined.

The number of times of energization can be one regardless of the number of protrusions 24. The pressing force at this time depends on the plate thickness, but is in the range of 0.2 kN to 2 kN per protrusion 24. The energizing current is 2 kA to 5 kA per protrusion. Further, the energizing time is in the range of 15 msec to 60 msec.

It has been confirmed that when a large current is passed in a design in which the distances between the protrusions 24 are short, the melted portions are pulled by each other and move due to the Lorentz force, and a long protrusion-like portion is formed. This part does not affect the welding strength, and in the worst case, it is removed by the impact of opening and closing and becomes a foreign substance. In the configuration of the first embodiment, for example, if this foreign matter is caught between the spacer 22 and the fixed iron core 30, the attractive force between the iron cores at the time of closing the pole is reduced, which hinders the opening / closing operation of the electromagnet 10. There is a fear. Therefore, in order to prevent the above-mentioned long protrusion-like portion from being formed, it is desirable that the distance between the protrusions 24 is 10 mm or more.

Further, in general, a resistance welding method in which welding is performed without providing protrusions is often used, but it is necessary to perform welding by sandwiching welded portions one by one using a thin electrode having a diameter of about several mm. When applied to the case where a plurality of welded portions Y are provided as in this case, the process of first aligning the welded portions and then sandwiching the welded portions and energizing the welded portions is repeated a plurality of times as many times as the number of the welded portions. As a result, it takes a long time to perform all welding, and when welding the second and subsequent welds, the current circulates in the previously welded weld and the current in the part to be welded decreases, resulting in insufficient welding. There is a risk of becoming.

On the other hand, according to the welding method shown in the first embodiment, positioning of the electrodes becomes unnecessary by energizing the spacer 22 and the movable iron core 20 by sandwiching the spacer 22 and the movable iron core 20 by a pair of flat plate-shaped electrodes larger than the spacer 22. .. Further, since a method of pressurizing the protrusion 24 and the movable iron core 20 in contact with each other and energizing a large current between the movable iron core 20 and the spacer 22 main body via the protrusion 24 is adopted, one energization is required. It becomes possible to generate a plurality of welded portions Y, which is advantageous in terms of productivity.

In the first embodiment, a spherical shape is exemplified as the shape of the protrusion 24, but the shape is not limited to this, and for example, a conical shape may be used. Further, although the shape of the back side of the protrusion 24 and the shape of the front side of the protrusion 24 are both spherical, they do not necessarily have to be the same shape. For example, the front surface is spherical and the back surface is conical. There is no problem even if it is a combination.

As a precaution when forming the protrusions 24 on the spacer 22, it is desirable that the shapes and heights of the plurality of protrusions 24 are the same. If the heights of the protrusions 24 are not uniform, one protrusion 24 is in contact with the movable iron core 20, but the other protrusions 24 are not in contact with each other, and the non-contact protrusions 24 cannot be welded. This is because there is a risk.

There are several types of power supplies used for welding, but it is particularly desirable to use a capacitor-type power supply that controls a constant current by inverter control when discharging charges after storing charges in a capacitor. With this power supply, a large current can be passed in a short time, and the energy required for welding can be set to the minimum necessary, so that the generation of spattered foreign matter and the explosion during welding are suppressed. However, stable welding is possible.

Further, in the first embodiment, an example in which the protrusion 24 is provided on the spacer 22 side is shown, but it is not always necessary to provide the protrusion 24 on the spacer 22, and conversely, the protrusion may be provided on the movable iron core 20 side. Even in that case, the welding procedure is as described above and does not change.

The electromagnet 10 in the first embodiment, a method of manufacturing a magnetic switch 100, electromagnets, and according to the manufacturing method of the electromagnetic switch, magnetism remaining in the fixed iron core 30 and the movable iron core 20 after stopping the energization of the electromagnet 10 Since a plurality of protrusions 24 are provided on the non-magnetic thin plate-shaped spacer 22 and the protrusions 24 can be welded to the movable iron core 20 at a time, the joining process is expected to be significantly shortened and the productivity is high.

Further, since an auxiliary material for joining such as silver wax is not required, the cost of joining can be reduced.

Embodiment 2.
Hereinafter, the electromagnet according to the second embodiment, the electromagnetic switch, electrostatic method for producing a magnet, and a method of manufacturing the electromagnetic switch, with reference to FIG, will be mainly differences from the first exemplary embodiment.
FIG. 5A is a view of the fixed iron core 230 as viewed from the spacer 232 side.
FIG. 5B is a side view of the fixed iron core 230.

In the first embodiment, the spacer 22 is welded to the movable iron core 20, but in the present embodiment, the spacer 232 is welded to the fixed iron core 230. As described above, it goes without saying that the spacer 232 has the same effect as that of the first embodiment even if it is welded and fixed to the fixed iron core 230 side instead of the movable iron core 20. As shown in FIGS. 5A and 5B, when the spacer 232 is welded to the iron core (regardless of whether it is movable or fixed) via a protrusion, a convex shape remains in the welded portion Y, and a convex shape remains between the spacer 232 and the iron core. , It is inevitable that a minute gap d remains. This also applies to the welded portion Y of the first embodiment.

In our experiment, it was found that the thicker the spacer 232, the larger the gap d. It was confirmed that when the gap d becomes large, the spacer 232 tends to be easily peeled off in the opening / closing repeated test of the electromagnet 10. Therefore, it is desirable to make the gap d as small as possible, and it is desirable to make it 0.2 mm or less, more preferably 0.1 mm or less.

In the second embodiment, the number of welded portions Y is five. For the spacer 232 having a rectangular shape and a relatively small difference between the long side and the short side, it is effective to provide the welded portions Y diagonally with the four corners of the spacer 232. Further, for those having a small difference between the long side and the short side, welded portions Y may be provided only at four points at the four corners.

According to the method for manufacturing the electromagnet 10, the electromagnetic switch 100, and the electromagnet according to the second embodiment, a non-magnetic thin plate that prevents magnetism remaining in the fixed iron core 230 and the movable iron core 20 after the energization of the electromagnet 10 is stopped. Since a plurality of protrusions 24 are provided on the spacer 232 and the protrusions 24 can be welded to the fixed iron core 230 at one time, a significant reduction in the joining process time is expected.

8A and 8B are two views showing a modified example of the movable iron core. FIG. 8A is a view of the fixed iron core 230B viewed from the side where the spacer is welded, and FIG. 8B is a side view of the fixed iron core 230B.

Although an example in which the protrusion 24 is provided on the spacer has been shown so far, the protrusion 24B may be provided on the side of the fixed iron core 230B as shown in FIGS. 8A and 8B. Generally, since the spacer is a thin plate, it is easier to process protrusions than an iron core. However, at the time of welding, if the melting condition on the iron core side is poor, it may be advantageous to provide a protrusion on the iron core side. Needless to say, even if a protrusion is provided on the iron core side, welding can be performed by adjusting the welding conditions.

9A, 9B, and 9C are diagrams showing examples of arrangement of other protrusions.
FIG. 9A is a plan view of the spacer 232C.
FIG. 9C is a view of the fixed iron core 230C as viewed from the side where the spacer 232C is welded.
FIG. 9B is a diagram showing a state in which the spacer 232C is welded to the fixed iron core 230C.
As shown in FIGS. 9A, 9B, and 9C, the same welding can be performed even if the protrusions 24C and 24B are provided on both the spacer 232C and the fixed iron core 230C.

In this example, three protrusions 24C1 out of a total of six protrusions are provided on the spacer 232C, and the remaining three protrusions 24C2 are arranged on the fixed iron core 230C side at positions that are the vertices of a triangle, respectively, and after welding. Has a rectangular arrangement in which all the welded portions Y are arranged. By changing the heights of the protrusions 24C1 and 24C2, the heights of the protrusions 24C1 and 24C2 are supported at three points, whichever is higher, and the stability of the spacer 232C before welding can be expected to be improved.

Embodiment 3.
Hereinafter, the electromagnet according to the third embodiment, the electromagnetic switch, a method of manufacturing a conductive magnet, and a method of manufacturing the electromagnetic switch, with reference to FIG, will be described while focusing on the difference relative to the first and second embodiments.
FIG. 6 is a view of the fixed iron core 330 as viewed from the spacer 332 side.
The outer peripheral shape of the contact surface of the fixed iron core 330 is circular, and the spacer 332 is configured to have a slightly smaller circular shape having the same center point O as the outer circumference of the fixed iron core 330.

Further, the welded portions Y are provided at three positions that are the vertices of the equilateral triangles centered on the center point O. If the number of welded portions Y = the number of protrusions before welding is set to three, the contact between the fixed iron core 330 and the spacer 332 is stable even if the height of the protrusions 24 varies, so that each welded portion Y The contact resistance is stable, and stable energization and welding are possible. Even if the outer peripheral shape of the contact surface of the fixed iron core is quadrangular and the shape of the spacer is circular, the same effect is obtained.

Embodiment 4.
Hereinafter, the electromagnet of the fourth embodiment, the electromagnetic switch, electrostatic method for producing a magnet, and a method of manufacturing the electromagnetic switch, with reference to FIG, will be mainly described Embodiments 1 to 3 and different parts of the embodiment.
FIG. 7 is a view of the fixed iron core 430 viewed from the spacer 432 side.
The outer peripheral shape of the contact surface of the fixed iron core 430 is rectangular, and the long side is considerably longer than the short side.
Welded portions Y along the edges of the long sides of each are provided at three locations. Further, two welded portions Y adjacent to the edge of one long side and two welded portions Y on the same side in the longitudinal direction as the two welded portions Y on the other long side edge. Another weld Y is provided, which is arranged on the intersection of diagonal lines of a square having a total of four welds Y as vertices. Therefore, in FIG. 7, the number of welded portions Y arranged on the intersections of the diagonal lines is two, and the total number of welded portions Y is eight.

According to this configuration, even when a rectangular spacer 432 having a large aspect ratio is adopted, the welding strength of the fixed iron core 430 and the spacer 432 is not impaired, and the spacer 432 can be reliably fixed.

Embodiment 5.
Hereinafter, the method for manufacturing an electromagnet according to the fifth embodiment will be described with reference to the drawings.
FIG. 10 is a diagram showing a procedure for positioning the movable iron core 20 and the spacer 22 made of SUS before welding by using the positioning jig 500.
FIG. 11 is a flow chart showing a process of welding the spacer 22 and the movable iron core 20.

First, a positioning jig 500 having an opening 22k in which a portion where the spacer 22 is to be installed is hollowed out is placed on the welded surface 20s of the movable iron core 20 (step S001: positioning jig mounting step). Next, the two spacers 22 are fitted and arranged along the edge of the opening 22k. (Step S002: Spacer placement step). By arranging the spacers in this way, the position of the spacer 22 with respect to the movable iron core 20 can be accurately positioned.

FIG. 12 is a diagram showing the dimensional relationship between the positioning jig 500 and the spacer 22, and shows the state after the positioning is completed and before welding.
The spacer 22 is pressurized by the electrode 600, but is not yet energized.
FIG. 13 is a diagram showing a state in which energization for welding (step S003: welding step) is completed, welding is completed, but the electrode 600 is still pressurizing.

In FIGS. 12 and 13, the thickness of the portion of the spacer 22 excluding the conical protrusion 24B is hs, the height of the protrusion 24B provided on the spacer 22 before welding is ht, and the portion of the spacer 22 in contact with the spacer 22 of the positioning jig 500. Assuming that the thickness is hj, by setting the three dimensional relationships so that ht <hj ≦ hs, welding is performed while leaving a portion where the positioning jig 500 and the spacer 22 are in contact with each other before welding (hj-ht> 0). Later, it is possible to secure a gap (hs + d−hj ≧ 0) in which the positioning jig 500 and the electrode 600 do not come into contact with each other, or are not pressurized even if they come into contact with each other. As a result, the spacer 22 and the movable iron core 20 can be welded (step S003: welding step) with the positioning jig 500 installed, and the accuracy of the welding positions of both can be improved.

FIG. 14 is a diagram showing another example of the positioning jig.
The positioning jig 500B is obtained by cutting and opening both ends of the positioning jig 500 in the longitudinal direction at a portion including a part of the above-mentioned opening 22k. It is possible to improve the workability of installing the spacer 22 while maintaining the positioning accuracy of the spacer 22.

As described above, the protrusions may be provided on the fixed iron core side, or even when the protrusions are provided on both sides, the same effect can be obtained if the height of the protrusions is ht.

It is desirable to use an insulator for the positioning jigs 500 and 500B, and a resin such as glass epoxy or monomer cast nylon, or a material such as ceramic can be applied. In the present embodiment, the spacer is rectangular, but it goes without saying that other shapes such as the above-mentioned circular shape can be applied.

In each of the above embodiments, SUS304 is exemplified as the material of the spacers 22, 232, 332, and 432, but other austenitic stainless steel materials such as SUS300 series, which are not tempered to increase the hardness, are used. Needless to say, if there is, the same effect can be obtained.

Regarding the phenomenon that austenitic stainless steel is magnetized by processing, it is known that magnetization can be suppressed by increasing the nickel content in terms of materials, and although the material price rises, SUS305, which has a high nickel content, , SUS316 and the like can be selected to significantly reduce the magnetization due to processing.

Further, as the material of the iron core, an integral shape is exemplified, but it goes without saying that the same effect can be obtained by using an electromagnetic steel plate or a material obtained by laminating and integrating magnetic steel plates such as cold-rolled steel plates.

Although the present application describes various exemplary embodiments and examples, the various features, embodiments, and functions described in one or more embodiments are applications of a particular embodiment. It is not limited to, but can be applied to embodiments alone or in various combinations. Therefore, innumerable variations not illustrated are envisioned within the scope of the techniques disclosed in the present application. For example, it is assumed that at least one component is modified, added or omitted, and further, at least one component is extracted and combined with the components of other embodiments.

10 electromagnet, 20 movable iron core,
22,232,232C, 332,432 spacer, 22k opening,
24, 24B, 24C1, 24C2 protrusions, 25 resin molded products,
30, 30a, 30b, 230, 230B, 330, 430 Fixed iron core,
33 base plate, 34 lower housing, 40 fixed contacts, 50 movable contacts,
55 Upper housing, 70, 70a, 70b drive coil, 100 electromagnetic switch,
500, 500B positioning jig, 600 electrodes, O center point, Y weld, d gap.

Claims (10)

Movable iron core and
A fixed iron core arranged to face the movable iron core and
An electromagnet having a drive coil wound around the fixed iron core.
One of the movable core or the fixed core is
A spacer made of a thin plate, which is a single plate of austenitic stainless steel and is a JIS standard 2B material or a JIS standard 2D material, is provided on the surface facing the other iron core.
The spacer and the iron core are electromagnets provided on at least one of the spacer or the iron core and fixed to each other by welding by a welded portion having a convex shape with respect to the other. The electromagnet according to claim 1, wherein the spacer is a rectangle, and the welded portions are arranged at four corners of the rectangle and two midpoints on the long side of the rectangle, for a total of six locations. The electromagnet according to claim 1, wherein the spacer has a circular shape, and the welded portion is provided at three positions serving as vertices of a triangle having the same center point as the center point of the spacer. The spacer is rectangular and is the same in the longitudinal direction as the two welded portions adjacent to the edge of one long side of the spacer and the two welded portions provided on the edge of the other long side. The electromagnet according to claim 1, further comprising two welds on the side and another weld arranged on the intersection of diagonal lines of a rectangle having the four welds as vertices. The electromagnet according to any one of claims 1 to 4,
A fixed contact that is insulated and connected to the fixed iron core,
An electromagnetic switch including a movable contact that is insulated and connected to the movable iron core that is brought into contact with and separated from the fixed contact in conjunction with the drive of the movable iron core. The method for manufacturing an electromagnet according to any one of claims 1 to 4.
The spacer or the protrusion provided on at least one of the iron cores is brought into contact with the other, and the spacer and the iron core are sandwiched between a pair of electrodes and pressurized, and electricity is applied between the electrodes to form the welded portion. A method of manufacturing an electromagnet having a welding process. The method for manufacturing an electromagnet according to claim 6, further comprising a spacer arranging step of positioning the spacer on the welded surface of the iron core by a positioning jig. The method for manufacturing an electromagnet according to claim 7, wherein the positioning jig has an opening in which a portion for installing the spacer is hollowed out. Assuming that the thickness of the portion of the spacer excluding the protrusion is hs, the height of the protrusion is ht, and the thickness of the positioning jig is hj, ht <hj ≦ hs.
The method for manufacturing an electromagnet according to claim 8, wherein the welding step is performed with the positioning jig installed. According to any one of claims 6 to 9, three protrusions are arranged on the spacer and the iron core, respectively, and the three protrusions are arranged at positions at which the vertices of the triangle are formed. The method for manufacturing an electromagnet according to the description.

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