JP6593188B2 - Method of joining base plate and pipe of magnetic contactor, and method of manufacturing magnetic contactor - Google Patents

Description

  The present invention relates to a method for joining a pipe to a base plate constituting a sealed container of an electromagnetic contactor, and a method for manufacturing an electromagnetic contactor.

For example, in the electromagnetic contactor described in Patent Document 1, the gas inside the sealing container is evacuated to a metal base plate constituting a sealing container in which the stationary contact and the movable contact are housed in an airtight manner. Alternatively, a metal pipe for sealing gas inside the sealed container is joined by brazing.
That is, a pipe insertion hole communicating with the inner and outer walls of the sealing container is formed in the base plate. After inserting the pipe insertion hole from the outer wall of the base plate, the opening peripheral edge of the pipe insertion hole on the outer wall side and the pipe The outer periphery is joined by brazing.

JP 2012-134121 A (see FIG. 8)

By the way, the pipe is inserted with a predetermined gap between the inner peripheral surfaces of the pipe insertion holes, and when the base plate and the pipe are brazed, the molten brazing material is And between the pipe insertion holes. Since the brazing material that has flowed between the pipe outer peripheral surface and the pipe insertion hole in this manner is easily vaporized of organic substances adhering to the base plate and the pipe and metal vapor, voids are likely to be generated inside the brazing material.
As described above, the void generated inside the brazing material between the pipe insertion hole of the base plate and the outer peripheral surface of the pipe easily deteriorates the brazed portion over time, and the airtightness of the joint portion of the base plate and the pipe is reduced. May decrease.

  Accordingly, an object of the present invention is to provide a method for joining a base plate and a pipe of an electromagnetic contactor and a method for manufacturing an electromagnetic contactor that can improve the airtightness of the joint between the base plate and the pipe.

  In order to achieve the above object, a method for joining a base plate and a pipe of an electromagnetic contactor according to an aspect of the present invention includes a first step of inserting a pipe into a pipe through hole formed in the base plate, and a pipe through hole. A pipe extending from the base plate, and a second step of expanding the pipe by inserting a pipe expansion member into the pipe inserted into the pipe to form an expanded portion in which the inner peripheral surface of the pipe through-hole and the outer peripheral surface of the pipe are in close contact with each other And a third step of brazing the outer peripheral surface of the base plate and the surface of the base plate on the extending direction side of the pipe.

  According to the method of joining the base plate and the pipe of the magnetic contactor according to the present invention, the inner peripheral surface of the pipe insertion hole of the base plate and the outer peripheral surface on one end side of the pipe inserted into the pipe insertion hole are in close contact. Since voids due to brazing do not occur, the airtightness of the joint between the base plate and the pipe can be improved.

It is sectional drawing which shows the gas sealing type structure of the magnetic contactor of 1st Embodiment which concerns on this invention. It is an external appearance perspective view of the gas sealed type structure of the electromagnetic contactor of 1st Embodiment. It is a figure which shows the structure of the die | dye and punch used when joining a pipe to the base board which comprises the sealing container of the electromagnetic contactor of 1st Embodiment. It is the figure which showed the state which plastically deformed the pipe inserted in the base board in 1st Embodiment. It is a figure which shows the state which has arrange | positioned the annular | circular brazing material around the pipe integrated with the base plate in 1st Embodiment. It is a figure which shows the state which melt | dissolved the annular | circular brazing material around the pipe in the heating furnace in the first embodiment. It is the graph which compared the drawing strength of the pipe joined to the base board with the past and this invention.

Next, a first embodiment of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between the thickness and the planar dimensions, the ratio of the thickness of each layer, and the like are different from the actual ones. Therefore, specific thicknesses and dimensions should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.
The first embodiment described below exemplifies an apparatus and method for embodying the technical idea of the present invention, and the technical idea of the present invention is the material, shape, and structure of component parts. The arrangement is not specified below. The technical idea of the present invention can be variously modified within the technical scope defined by the claims described in the claims.

[About capsule structure of electromagnetic contactor]
FIG. 1 is a cross-sectional view showing a gas-sealed structure (hereinafter referred to as a capsule structure 13) of a first embodiment of an electromagnetic contactor according to the present invention, and FIG. 2 is a diagram of the capsule structure 13 shown in FIG. It is an external perspective view.
In the first embodiment shown in FIG. 1, a bowl-shaped arc extinguishing chamber 1 integrally formed by firing, for example, ceramic with an open lower end surface, and a pair of, for example, copper fixed contacts on the upper side wall surface of the arc extinguishing chamber 1 The child 2 penetrates at a predetermined interval and is joined by brazing.

An arc extinguishing chamber is formed by joining a cylindrical portion 4a of the first connecting member 4 which is formed in a protruding shape to the open end 1a of the arc extinguishing chamber 1 to which the fixed contact 2 is brazed. The joint 6 is assembled. The joining of the stationary contact 2 and the cylindrical portion 4a of the first connecting member 4 to the arc extinguishing chamber 1 can be integrated by brazing at the same time. At this time, in the arc extinguishing chamber 1, a metal layer or a metal film is formed by performing a metallization process at the brazing position of the cylindrical portion 4a of the fixed contact 2 and the first connecting member 4, and the metal layer or metal The film is Ni plated.
The assembled arc-extinguishing chamber joint 6 has a flange portion 4b integrally connected to the cylindrical portion 4a of the first connecting member 4 adhered to the iron base plate 7 and joined by seal welding.
Further, the copper pipe 3 is joined to the iron base plate 7 in a state of penetrating the base plate 7.

The bottomed cylindrical cap 8 whose one end is sealed is obtained by joining a cylindrical portion 5a having an extended convex shape of the second connecting member 5 to the opening end portion 8a of the cap 8 by seal welding. The joint 12 is assembled. In order to attach the cap joint portion 12 to the base plate 7, the flange portion 5 b provided on the second connecting member 5 is brought into close contact with the base plate 7 and is sealed.
At this time, the arc-extinguishing chamber joint 6 and the cap joint 12 are attached so as to communicate with each other through an insertion hole 7 a provided in the base plate 7. Thereby, the capsule structure part 13 of an electromagnetic contactor is assembled.

The method of joining the arc extinguishing chamber 1, the stationary contact 2 and the first connecting member 4 of the arc extinguishing chamber joint 6 can be performed simultaneously by brazing in the furnace. The first and second connecting members 4 and 5 are preferably formed using a low expansion coefficient material, the base plate 7 using a magnetic material, and the cap 8 using a nonmagnetic material.
When assembling the capsule structure 13, the components shown in FIG. 5 of Patent Document 1, for example, are arranged, although not shown in FIG. That is, a movable contact having a movable contact disposed in the arc extinguishing chamber 1 on the first surface (surface facing the arc extinguishing chamber 1) 7b of the base plate 7, a movable shaft for supporting the movable contact, and the movable A contact spring for pressing the movable contact disposed around the shaft against the fixed contact of the fixed contact 2 is disposed, and an insertion hole is formed in the second surface (surface to which the cap joint 12 is connected) 7c of the base plate 7. A movable iron core and a return spring connected to a movable shaft extending through 7a are arranged.

The arc extinguishing chamber joint 6 is disposed on the base plate 7 so as to cover the movable contact, the movable shaft, and the contact spring, and the cap joint 12 is disposed so as to cover the movable shaft, the movable iron core, and the return spring. The arc extinguishing chamber joint 6 and the cap joint 12 are welded to the base plate 7 by seal welding.
When the capsule structure part 13 of the magnetic contactor is assembled, a gas exhaust device (not shown) is connected to the pipe 3 joined to the base plate 7 to evacuate the gas inside the capsule structure part 13, and the gas supply part ( A sealed gas (hydrogen gas, nitrogen gas, a mixed gas of hydrogen and nitrogen, or air) is sealed inside the capsule structure portion 13 via the pipe 3 (not shown). When the gas filling into the capsule structure 13 is completed, the pipe 3 is crushed and welded to seal the pipe 3.

[Pipe expansion member for plastic deformation of the pipe of the first embodiment]
Next, a pipe expansion member used when the pipe 3 is joined to the base plate 7 will be described.
As shown in FIG. 3, the iron base plate 7 is formed with a pipe through hole 7d having an inner diameter d1 penetrating from the first surface 7b facing the arc extinguishing chamber 1 to the second surface 7c to which the cap joint portion 12 is connected. And is supported by a base support (not shown).
A tapered inner surface 15 is formed on the first surface 7b side of the pipe through hole 7d of the base plate 7 so that the diameter gradually increases toward the opening end surface and the opening has an inner diameter d2 (d2> d1). The tapered inner surface 15 is a conical surface that is inclined at an angle of 45 ° with respect to the central axis of the pipe through-hole 7d.

The copper pipe 3 is a cylindrical hollow tube having an outer diameter d3 (d3> d1) and an inner diameter d4 that is slightly smaller than the inner diameter d1 of the pipe through-hole 7d, and the base plate is held while the lower end of the pipe is held on the die 16 7 is inserted into the pipe through hole 7d, and the upper end of the pipe is flush with the first surface 7b of the base plate 7.
The pipe expansion member is a solid cylindrical member that plastically deforms the pipe 3 from the inner tube, and uses, for example, a punch 17.
This punch 17 is integrally formed with the punch body 18 and the lower part of the punch body 18, has an outer diameter d 5 larger than the inner diameter d 4 of the pipe 3 by a predetermined amount, and is a cylindrical enlarged diameter portion longer than the pipe through-hole 7 d. 19, an insertion guide portion 20 formed by gradually reducing the diameter toward the distal end side of the enlarged diameter portion 19, and formed continuously from the proximal end of the enlarged diameter portion 19, and as being separated from the enlarged diameter portion 19. And a crimped portion 21 formed by gradually expanding the diameter. The caulking portion 21 is a conical surface that is inclined at an angle of 45 ° with respect to the central axis of the punch 17.

[Method for joining pipe to base plate of first embodiment]
Next, a method for joining the pipe 3 to the base plate 7 will be described with reference to FIGS.
First, as shown in FIG. 4, when the punch 17 is lowered from the first surface 7 b side of the base plate 7, the enlarged diameter portion 19 comes into contact with the inner peripheral surface of the pipe 3, and the pipe 3 is plasticized into an expanded state. By deforming, the expanded portion 22a is formed in which the outer peripheral surface of the pipe 3 and the inner peripheral surface of the pipe through hole 7d of the base plate 7 are in close contact with each other without any gap.
Further, the punch 17 is further inserted, and the opening end of the expanded tube portion 22a is further plastically deformed radially outward by the caulking portion 21 formed integrally with the expanded diameter portion 19, and the outer peripheral surface of the expanded end portion of the expanded tube portion 22a. A tube expansion end 22b is formed in which the taper inner surface 15 of the base plate 17 is completely adhered.

Next, as shown in FIG. 5, the first surface 7 b and the second surface 7 c of the base plate 7 are turned upside down so that the pipe 3 rises from the pipe through hole 7 d of the base plate 7.
Then, an annular brazing material 23 is disposed on the second surface 7 c around the pipe 3.
Next, as shown in FIG. 6, the base plate 7 in which the annular brazing material 23 is arranged around the pipe 3 is arranged inside the heating furnace 24, and the brazing material 23 is melted by the heat of the heating furnace 24. The opening peripheral edge of the pipe through hole 7d on the second surface 7c side of the base plate 7 and the outer periphery of the pipe 3 are joined by brazing.

Next, the effect of the first embodiment described above will be described.
By forming the expanded portion 22a in which the inner peripheral surface of the pipe through hole 7d and the outer peripheral surface of the pipe 3 are in close contact with each other, the brazing material 23 does not flow between the pipe through hole 7d and the pipe 3, so that the pipe 7 and the pipe 3 The joint portion can improve the hermeticity of the joint portion without being affected by voids generated inside the brazing material 23, and can also have a joining strength by brazing.
Further, since the punch 17 has the enlarged diameter portion 19 and the caulking portion 21 formed integrally, the step of forming the expanded portion 22 a in the pipe 2 and the expanded end portion 22 b in which one end of the pipe 3 is brought into close contact with the tapered inner surface 15. The process of forming can be performed continuously, and the operation of plastically deforming the pipe 3 can be easily performed.

Further, since the pipe 3 fixed to the base plate 7 can be arranged alone in the heating furnace 24 without being supported by other members, the heating operation for melting the brazing material 23 can be simplified. Can be planned.
Further, in the first embodiment, as shown in FIG. 1, in addition to the brazing of the base plate 7 and the pipe 3 with the brazing material 23, the pipe 3 is brought into close contact with the pipe through hole 7d, and the pipe is expanded toward the first surface 7b. Since the end 22b is formed, the pulling strength of the pipe 3 that can sufficiently withstand the pulling force in the direction indicated by the arrow in FIG. 1 can be increased.

In the first embodiment described above, the outer diameter d3 of the pipe 3 is set to 4 mm, the inner diameter d4 of the pipe 3 is set to 2 mm, and the outer diameter d5 of the expanded portion 19 of the punch 17 is set to 2.2 mm. Set.
The caulking portion 21 of the punch 17 is inclined at an angle of 45 ° with respect to the central axis of the punch 17, and the tapered inner surface 15 corresponding to the caulking portion 21 is also 45 ° with respect to the central axis of the pipe through hole 7d. However, the caulking portion 21 and the tapered inner surface 15 may be formed so as to be inclined within a range of 15 ° to 60 °.

Here, FIG. 7 is a graph comparing the pull-out strength of the pipe joined to the base plate between the prior art and the present invention.
In Comparative Example 1 shown on the horizontal axis of FIG. 7, the melted brazing material described in the column of the problem to be solved by the above-described invention flows into the gap between the pipe outer peripheral surface of the base plate and the pipe insertion hole. This is a base plate-to-pipe joining member that tends to occur.
In Comparative Examples 2 to 4, the pipe 3 inserted into the pipe through hole 7d of the base plate 7 is a member that is plastically deformed in the expanded state, but the base plate 7 and the pipe 3 are joined by brazing. There is no member. Here, in Comparative Example 2, the size of the outer diameter d5 of the enlarged diameter portion 19 of the punch 17 is set to 2.22 mm, and in Comparative Example 3, the outer diameter d5 of the enlarged diameter portion 19 of the punch 17 is set to 2.26 mm. In Comparative Example 4, the dimension of the outer diameter d5 of the enlarged diameter portion 19 of the punch 17 is set to 2.30 mm.

The invention 1 is a member in which the outer diameter d5 of the enlarged diameter portion 19 of the punch 17 is set to 2.22 mm, and the base plate 7 and the pipe 3 are joined by the brazing material 23.
The invention 2 is a member in which the outer diameter d5 of the enlarged diameter portion 19 of the punch 17 is set to 2.26 mm, and the base plate 7 and the pipe 3 are joined by the brazing material 23.
Further, the invention 3 is a member in which the outer diameter d5 of the enlarged diameter portion 19 of the punch 17 is set to 2.30 mm, and the base plate 7 and the pipe 3 are joined by the brazing material 23.

As is apparent from FIG. 7, when the pipe 3 inserted into the pipe through-hole 7d of the base plate 7 shown in Comparative Examples 2 to 4 is brought into close contact, a larger pulling strength than that of Comparative Example 1 having a conventional structure is generated. Can not do it.
On the other hand, as shown in the inventions 1 to 3, the pipe 3 inserted into the pipe through hole 7d of the base plate 7 is brought into close contact, and the base plate 7 and the pipe 3 are joined by the brazing material 23, It can be seen that the pulling strength is greater than that of Comparative Example 1 having the conventional structure.

DESCRIPTION OF SYMBOLS 1 Arc-extinguishing chamber 1a Open end 2 Fixed contact 3 Pipe 4 1st connection member 4a Tube part 4b Flange part 5 2nd connection member 5a Tube part 5b Flange part 6 Arc-extinguishing chamber joint part 7 Base plate 7a Insertion hole 7b First surface 7c Second surface 7d Pipe through hole 8 Cap 8a Open end 12 Cap joint 13 Capsule structure 15 Tapered inner surface 16 Die 17 Punch 18 Punch body 19 Expanding portion 20 Inserting guide portion 21 Caulking portion 22a Expanding portion 22b Expanded end 23 Brazing material 24 Heating furnace d1 Inner diameter d2 of pipe insertion hole Taper inner diameter d3 Pipe outer diameter d4 Pipe inner diameter d5 Outer diameter of expanded section

Claims (5)

A method of joining a base plate constituting a sealed container of an electromagnetic contactor and a pipe communicating with the inside of the sealed container,
A first step of inserting the pipe into a pipe through hole formed in the base plate;
A second step of performing pipe expansion by inserting a pipe expansion member into the pipe inserted into the pipe through hole, and forming an expanded portion in which the inner peripheral surface of the pipe through hole and the outer peripheral surface of the pipe are in close contact with each other; ,
A method of joining a base plate and a pipe of an electromagnetic contactor, comprising: a third step of brazing the outer peripheral surface of the pipe extended from the base plate and the surface of the base plate on the extending direction side of the pipe. A tapered inner surface is formed on the opposite side of the pipe through-hole to the extending direction of the pipe, and the diameter of the taper increases toward the opening end surface of the base plate.
2. The method for joining a base plate and a pipe of an electromagnetic contactor according to claim 1, wherein in the second step, the outer peripheral surface of the open end of the pipe expansion portion forms a pipe expansion end portion in close contact with the tapered inner surface. . The pipe expanding member has a cylindrical outer diameter portion that is larger than the inner diameter of the pipe by a predetermined amount and is longer than the pipe through-hole,
The base plate and pipe of an electromagnetic contactor according to claim 1 or 2, wherein, in the second step, the expanded portion is formed by inserting the entire enlarged diameter portion into the pipe through hole. Joining method. The pipe expanding member includes a cylindrical enlarged diameter portion that is larger than the inner diameter of the pipe by a predetermined amount and is longer than the pipe through-hole, and a crimped portion integrally formed with the enlarged diameter portion,
In the second step, the pipe expanding member is formed by inserting the entire expanded diameter portion into the pipe through-hole to form the expanded tube portion, and until the expanded end portion is in close contact with the caulking portion and the tapered inner surface. The base plate of an electromagnetic contactor and the joining method of a pipe of Claim 2 characterized by the above-mentioned.   The manufacturing method of the electromagnetic contactor which comprised the sealing container with the base plate and pipe which were joined by the joining method of the base plate and pipe of the electromagnetic contactor of any one of Claim 1 to 4.

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