JPH0576165B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing a capacitor applied to a noise radio wave leakage prevention filter for a magnetron for a microwave oven, and particularly relates to a method for manufacturing a capacitor that is applied to a filter for preventing leakage of noise radio waves in a magnetron for a microwave oven, and particularly relates to a method for manufacturing a capacitor that is applied to a filter for preventing leakage of noise radio waves in a magnetron for a microwave oven, and in particular, to improve dielectric strength, insulation resistance, humidification withstand voltage, This invention relates to a method for manufacturing capacitors that can improve quality by imparting characteristics required for capacitors, such as heat cycle and capacitance.

[Background technology]

Generally, a magnetron generates high frequency energy from its oscillating unit body, and outputs the energy to a high frequency utilizing device, such as a microwave oven, through its output unit. However, the above-mentioned high frequency energy is high frequency energy other than the basic oscillation frequency including the basic oscillation frequency of the magnetron, such as UHF,
This includes TV band waves such as VHF, and some of these high-frequency energies propagate through the cathode terminal and are led to the outside, causing so-called unnecessary radiation to other communication equipment,
It has a negative effect on radio, television, etc.

Therefore, a noise leakage prevention filter consisting of a chiyoke coil, which is an inductor element, and a capacitor, which is a capacitive element, is connected between the cathode terminal of the magnetron and the ground to attenuate or eliminate the high frequency energy radiated from the cathode circuit. This prevents the effects on TVs, etc.

As a conventional technology for capacitors used in this noise leakage prevention filter, for example,
There are those shown in No. 134362 and Utility Model Application Publication No. 63-19743.

The capacitive element shown in Utility Model Application Publication No. 59-134362 surrounds a plate-shaped electrode having a through terminal with a dielectric sheet, and is tightly fixed and integrated with the inner surface of the wall of a filter box. It is constructed by protruding a dielectric sheet to the outside in a cylindrical shape. However, according to this capacitive element,
Since the capacitance formed between the plate electrode and the filter box is provided by welding a dielectric sheet to the through terminal, the capacitance formed between the plate electrode and the dielectric sheet or between the filter box and the dielectric There is a possibility that a gap may be generated between the body sheets, and there is a disadvantage that the capacitance is not formed uniformly. In addition, there are many manufacturing steps, which limits the ability to improve productivity and reduce costs.

On the other hand, the feedthrough capacitor shown in Utility Model Application No. 63-19743 has one end electrically connected to the input conductor of the cathode stem via an inductor element, and the other end connected to the center conductor connected to the magnetron drive power supply. , a cylindrical ground electrode disposed around the center conductor and in contact with the shield box; It consists of a bottomed through electrode electrically connected to the conductor, and a single resin insulator molded to cover the center conductor, cylindrical ground electrode, and bottomed through electrode. Specifically, the center diameter between the two electrodes is 12 mm, the interval is 1 mm, and the opposing length is 20 mm. (hereinafter referred to as "PBT resin") is used.
According to this feedthrough capacitor, the capacitance between both electrodes is formed by molding, so the above-mentioned problem can be solved.

In general, capacitors used in noise radio wave leakage prevention filters must have a dielectric strength that can withstand AC 10KV/1 minute, an insulation resistance of ¹⁰⁴ MΩ or more, and be kept at room temperature and 100% humidity.
AC8KV/2 minutes + AC10KV/2 minutes + under the conditions of
It has a humidification withstand voltage that can withstand 12KV/2 minutes, and after 10 cycles of -30° x 1h to 120° x 1h, there is no abnormality when applying AC 10KV for 1 minute at room temperature.
It is required that the capacitance individually exhibits a uniform value and that there is no variation, and for this purpose, the following items must be satisfied.

(1) The thickness of the molded insulator between the ground electrode and the capacitor electrode is uniform, there are no air bubbles in the insulator, and there is no molding distortion in the insulator.

(2) The insulator to which the ground electrode and capacitor electrode are fixed is in close contact with both electrodes, and there are no gaps.

(3) When molding the insulating part between the ground electrode and capacitor electrode, both electrodes should not be displaced or deformed within the mold cavity due to molding pressure.

[Problem to be solved by the invention]

However, the feedthrough capacitor shown in Utility Model Application No. 63-19743 mentioned above has the following problems and cannot satisfy the above requirements, and it is difficult to obtain the characteristics required for a capacitor. I can't.

(1) When molding glass fiber-filled PBT resin, the resin has poor fluidity and is difficult to mold.
Between the ground electrode and the penetration electrode, that is, the interval 1 mm,
It is difficult to mold the resin to a uniform thickness within a length of 20 mm, causing sinkage and bubbles in the molded area.

(2) In order to eliminate sink marks and bubbles in the molded part, the only way is to increase the molding pressure.Increasing the pressure improves the flow of the resin, but the center conductor and ground electrode inside the cavity of the molding die. This may cause the placement position of the through electrode to change. Furthermore, if the molded product is cylindrical, even if the variation is slight at one end, the variation at the other end becomes large. Furthermore, the thickness of both electrodes is 1.0mm.
Since it is around ~0.8mm, there is a risk of deformation due to molding pressure.

Therefore, an object of the present invention is to provide a method for manufacturing a capacitor that can mold a capacitor insulator to a uniform thickness without causing molding distortion or bubbles between a ground electrode and a capacitor electrode. .

A second object of the present invention is to provide a method for manufacturing a capacitor that allows a capacitor insulator to be firmly attached to a ground electrode and a capacitor electrode without any gaps.

A third object of the present invention is to provide a method for manufacturing a capacitor in which both electrodes are not displaced or deformed within a mold cavity due to the molding pressure during molding.

[Means to solve the problem]

In order to achieve the above-mentioned objects, the present invention molds a primary molded body on at least one surface of a flat ground plate to provide a flat plate electrode and a capacitor electrode for use in a capacitor having capacitor terminals protruding from both sides of the flat plate electrode. One side of the terminal is penetrated perpendicularly to the primary molded body, and a flat plate electrode is brought into close contact with the primary molded body, and secondary molding is performed from the flat plate electrode side to the ground plate and the capacitor terminal on the penetrating side. The present invention provides a method for manufacturing a capacitor in which the body is molded into a predetermined shape.

That is, the method for manufacturing a capacitor of the present invention is carried out as follows.

(1) Formation of primary molded body This is a process of forming a primary molded body on at least one surface of a flat ground plate by primary molding,
For example, a flat plate electrode accommodating body is formed on one side of the ground plate, and includes a bottom portion that can accommodate a flat plate electrode of a capacitor electrode, which will be described later, and a peripheral wall, and the other side of the ground plate holds a terminal for a capacitor that protrudes from the ground plate. form a holding part. The ground plate is formed with, for example, an insertion hole through which one side of the capacitor terminal is inserted, a resin outflow hole that connects the secondary molded body (described later) on both sides of the ground plate, and a fixing hole that connects the primary molded body on both sides. The flat electrode accommodating body and the holding part of the primary molded body are integrated through the insertion hole and the resin outflow hole, leaving a part of the insertion hole and the resin outflow hole, and , the primary molding forms a fixing protrusion that integrates the flat electrode housing through the fixing hole.

(2) Arrangement of capacitor electrode A flat plate electrode, and one side of the capacitor terminal of the capacitor electrode with capacitor terminals protruding from both sides of the flat plate electrode, is penetrated perpendicularly to the primary molding, and the flat plate electrode is primary molded. This is a step of bringing the capacitor terminal into close contact with the body, for example, by inserting one side of the capacitor terminal into an insertion hole formed in the ground plate and the primary molded body.

(4) Formation of secondary molded body A secondary molded body is formed by secondary molding from the opposite side of the capacitor terminal that has passed through the ground plate, that is, from the flat plate electrode side to the ground plate and the capacitor terminal that has passed through the ground plate. In this process, the capacitor terminals protruding from the holding part constituting the above-mentioned primary molded body are covered, and the surface of the flat electrode is flushed through the resin outflow hole formed in the primary molded body. Formed to cover the area.

[Effect]

Since the primary molded body is formed in advance along the ground plate, the primary molded body can be formed to have a uniform thickness without forming molding distortion, bubbles, etc., and furthermore,
Since the primary molded body is connected on both sides through the insertion hole and the resin outflow hole formed in the ground plate, the ground plate and the primary molded body can be brought into close contact with each other. Next, since the capacitor electrode is disposed in close contact with the primary molded body, movement of the ground plate and the capacitor electrode within the mold can be prevented. By preventing this movement, the above-mentioned purpose can be achieved.

〔Example〕

Hereinafter, the capacitor manufacturing method of the present invention will be explained in detail with reference to the accompanying drawings.

Figures 1a, b, and 2 show an example of the method for manufacturing a capacitor according to the present invention, and the thickness
Press-form a galvanized iron plate with a thickness of 0.6 mm.
Grounding mounting hole 11, fixing hole 12, vertical 10.3
A pair of insertion holes 13 with a width of 4.5 mm and a diameter of 3.6 mm
A vertical 36 having a pair of resin outflow holes 14 having a
A ground plate 10 with a width of 63 mm and a width of 63 mm is formed. Next, the ground plate 10 is placed in a mold cavity (not shown) for mold forming, and the temperature at the front part of the cylinder (not shown) of the injection molding machine is set to 259-263°C, and the temperature at the rear part is set to 244°C. ~248℃, nozzle temperature 258~260℃, injection molding time 3~7 seconds, injection pressure 48~55Kg/ ^cm2 , molding (cooling) time 6~10 seconds, mold temperature 50~55℃, A primary molded body 30 made of PBT resin mixed with glass fiber at a weight ratio of 20 to 30% on both sides of the ground plate 10
is formed by molding. That is, on one surface of the grounding plate 10, there is a flat plate electrode housing comprising a bottom part 31 having a thickness of 1.2±0.01 mm and having protrusions 35 arranged above and below approximately the center, and a peripheral wall part 32 rising from the bottom part 31 by a predetermined dimension. As shown in FIG.
The oval body 38 is integrated with the flat plate electrode housing 40 through the pair of insertion holes 13 of 0 and part of the two resin outflow holes 14, and further through the fixing hole 12 of the ground plate 10. A fixing protrusion 36 that integrates the flat electrode housing 40 is formed. At the same time, the insertion hole 13 of the ground plate 10 and the resin outflow hole 14 extend from the oblong body 38 to the flat electrode housing 40.
a pair of insertion holes 3 so that the remaining parts of the
3, and a resin outflow hole 34 is formed. and,
Terminals 21 for the power supply side capacitor with a width of 6mm and length of 30mm, and terminals 23 for the power supply side capacitor with a width of 3.0mm and a length of 14mm, both vertically and horizontally, are made by press-forming a nickel plated iron plate with a thickness of 0.8mm. The power supply side capacitor terminal 21 of the capacitor electrode 20, which is formed to protrude from the flat plate electrode 22 having a length of approximately 25 mm, is inserted into the insertion hole 33, and the protrusions 24 and 25 of the flat plate electrode 22 are inserted into the bottom of the flat electrode housing 40. The flat plate electrode 22 is brought into contact with the bottom part 31 so as to be engaged with both sides of the arrangement protrusion 35 formed on the bottom part 31. Next, the flat electrode 22 of the capacitor electrode 20 is placed in the flat electrode housing 40, and placed in the cavity of a molding die, and the elliptical body 38 and the elongated body 38 are molded at an injection pressure of 30 to 35 kg/cm ^{2 .} A secondary molded body 50 made of the same material as the primary molded body 30 is molded to cover the protruding power supply side capacitor terminal 21 and to fix the flat electrode 22 arranged in the flat electrode housing 40. (Fig. 4 a, b). That is, it has an oval insulating part 52 and a peripheral wall part 55 rising from the outer periphery of the oval insulating part 52 so as to cover the oval body 38 and a part of the power supply side capacitor terminal 21 protruding from the oval body 38. Resin outflow holes 3 formed in the primary molded body 30 to form the mold body 60
An electrode fixing portion 51 is formed on a part of the surface of the flat electrode 22 so as to be integrated with the mold body 60 via the electrode 4, thereby fixing the flat electrode 22. In this way, all the steps are completed, and a capacitor that can be applied to, for example, a noise radio wave leakage prevention filter of a magnetron for a microwave oven can be obtained. Note that a groove 37 is formed in the oval body 38 in order to improve the engagement of the secondary molded body 50.

3a, b, and c show a capacitor obtained by the manufacturing method described above, in which a ground plate 10 made of a flat galvanized iron plate having mounting holes 11 has peripheral walls of a secondary molded body 50 on both sides. 55 and the primary molded body 3
0 peripheral wall portions 32 are formed, and the peripheral wall portion 5
5, and a pair of power supply side capacitor terminals 21 and a pair of chiyoke coil side capacitor terminals 23 protrude from the peripheral wall portion 32, respectively, and the power supply side capacitor terminals 31 are connected to a driving power source (not shown) of the magnetron, The capacitor terminal 23 on the side of the chiyoke coil is connected to the cathode terminal of the magnetron via the chiyoke coil (not shown). A pair of flat plate electrodes 22 are arranged inside the peripheral wall 32 and are integrally formed with the power supply side capacitor terminal 21 and the chiyoke coil side capacitor terminal 32. 23 and the flat plate electrode 22 constitute the capacitor electrode 20 described above. The pair of flat electrodes 22 have protrusions 24 and 25.
(Accurate visual recognition is not possible due to the electrode fixing part 51)
is formed, and a protrusion 3 disposed between the protrusions 24 and 25
5 is formed, and together with the peripheral wall portion 32, the flat plate electrode 22
The movement of people is regulated. An electrode fixing part 51 of the secondary molded body 50 is provided on a part of the surface of the pair of flat plate electrodes 22, thereby fixing the capacitor electrode 20. A recess 54 is provided between the capacitor terminals 23 on the side of the electrode fixing part 51.
is formed from the electrode fixing part 51 to a part of the capacitor terminal 23 on the side of the capacitor coil, and together with the raised part 53, the creepage distance between the capacitor terminals 23 on the capacitor coil side is increased to prevent short circuits. An insulating part 52 of the secondary molded body 50 is formed inside the peripheral wall part 55 so as to insulate between the power supply side capacitor terminals 21.
A raised portion 56 is formed so as to partially cover the power supply side capacitor terminal 21. 36 is a fixing protrusion formed by the primary molded body 30, and is attached to the peripheral wall 3 through the fixing hole 12 formed in the ground plate 10.
2 to firmly fix the ground plate 10 and the primary molded body 30.

4a and 4b show cross-sectional views of the capacitor described above, and the ground plate 10 has a pair of insertion holes 13 through which a pair of power supply side capacitor terminals 21 are inserted, and a pair of insertion holes 13 located between the pair of insertion holes 13. , primary molded body 3
0, two resin outflow holes 14 are formed to connect the secondary molded body 50 on both sides of the ground plate 10, and the ground plate 1
A primary molded body 30 is formed by molding so as to be integrated on both sides of the body 0 through the insertion holes 13 and the resin outflow holes 14. The primary molded body 30 includes a bottom portion 3 formed on one surface of the ground plate 10.
1, and a flat plate electrode accommodating body 40 constituted by the peripheral wall portion 32, and formed on the other surface of the ground plate 10,
The flat electrode housing 40 is inserted through the fixing hole of the ground plate 10.
A fixing protrusion 36 that is formed on the other surface of the ground plate 10 and connects the through hole 13 and a part of the resin outflow hole through the insertion hole 13 and the resin outflow hole 14 of the ground plate 10. The insertion hole 33,
A pair of flat electrodes 22 are disposed inside the flat electrode housing 40, and a pair of flat electrodes 22 are arranged inside the flat electrode housing 40. The side capacitor terminal 21 is inserted through the insertion hole 33 of the primary molded body 30 and protrudes from the oval body 38. Further, the secondary molded body 50 is made of the same material as the primary molded body 30 and covers the oval body 38 and the power supply side capacitor terminal 21 protruding therefrom, and also covers the flat plate electrode arranged in the flat plate electrode housing 40. 22, and covers the oval body 38 and a part of the power supply side capacitor terminal 21 of the capacitor electrode 20, and a peripheral wall portion rising from the outer periphery of the insulating portion 52. 55, a raised portion 56 that covers a part of the protruding power supply side capacitor terminal 21, and a raised part 56 that is formed on the surface of a part of the flat electrode 22 arranged in the flat electrode housing 40, and Formed resin outflow hole 34
It is constituted by an electrode fixing part 51 that is integrated through the electrode fixing part 51. The electrode fixing portion 51 forms a raised portion 53 extending over the capacitor terminal 23 on the side of the York coil.

A capacitor obtained by such a manufacturing method has the following effects.

(1) Stable capacitance can be obtained because the ground plate and flat plate electrode can be placed close to each other at a small distance while maintaining good insulation.

(2) The primary molded body 3 is applied to both sides of the ground plate 10 through the resin outflow hole 14 and the insertion hole 13 of the ground plate 10.
0, molding pressure is applied to both surfaces of the ground plate 10, and the molding pressure can prevent the ground plate 10 from being deformed and from moving or misaligning within the mold.

(3) Since the primary molded body is molded on both sides of the ground plate 10, the bottom portion 31 of the primary molded body 30 can be molded to have a uniform thickness, and no air bubbles or the like are contained inside the primary molded body 30.

(4) Since the fixing protrusion 36 is formed on the other surface of the flat electrode housing 40 and the ground plate 10 through the fixing hole 12 formed in the ground plate 10, there is no gap between the fixing surfaces of the ground plate 10 and the bottom part 31. There is no need for close contact.

(5) Since the bottom portion 31 can be formed to have a uniform thickness, the flat electrode 22 can be in close contact with the bottom portion 31 without any gaps.

(6) Since the secondary molded body 50 is formed through the resin outflow hole 34 formed in the primary molded body,
Molding pressure during secondary molding is not applied locally, and an insulator without molding distortion, sink marks, or bubbles can be obtained, and each capacitor terminal of the capacitor electrode is not deformed.

The capacitor manufactured according to the present invention is preferably applied to a noise radio wave leakage prevention filter for a magnetron, but is not limited to this and can be applied to various uses.

〔Effect of the invention〕

As explained above, according to the capacitor manufacturing method of the present invention, a primary molded body is molded on at least one surface of a flat ground plate, and a flat plate electrode and capacitor terminals protrude from both sides of the flat plate electrode. One side of the capacitor terminal of the capacitor electrode is penetrated perpendicularly to the primary molded body, and the flat plate electrode is brought into close contact with the primary molded body, and from the flat electrode side to the ground plate and the capacitor on the penetrating side. Since the secondary molded body is molded into a predetermined shape over the terminal, the capacitor insulator can be provided with a uniform thickness without forming distortion or bubbles between the ground plate and the flat electrode. . Therefore, stable capacitance can be obtained. Further, since the primary molded body is connected on both sides through the fixing hole formed in the ground plate, the ground plate and the primary molded body can be brought into close contact with each other. Furthermore, it is possible to prevent displacement, deformation, etc. of the ground plate and the capacitor electrode within the mold.

[Brief explanation of the drawing]

Figures 1a, b and 2 are explanatory diagrams showing the method for manufacturing a capacitor of the present invention; Figures 3a, b,
FIG. 4c is an explanatory diagram showing a capacitor obtained by the manufacturing method of the present invention, and FIGS. 4a and 4b are a front sectional view and a side sectional view thereof. Explanation of symbols, 10...Ground plate, 11...Mounting hole, 12...Fixing hole, 13...Insertion hole, 14...
Resin outflow hole, 20... Capacitor electrode, 21...
...power supply side capacitor terminal, 22...flat plate electrode, 23...chiyoke coil side capacitor terminal, 24, 25...protrusion, 30...primary molded body, 31...bottom, 32...peripheral wall, 33... ...Insertion hole, 34...Resin outflow hole, 35...Arrangement projection,
36... Fixed protrusion, 37... Groove, 38... Oblong body, 40... Flat electrode housing, 50... Secondary molded body, 51... Electrode fixing part, 52... Oval shaped insulating part, 53 ... Protuberance, 54 ... Recess, 55 ... Peripheral wall, 56 ... Protrusion.

Claims (1)

[Scope of Claims] 1. A capacitor insulator is placed on one side of a flat ground plate having a capacitor terminal insertion hole and a resin outflow hole, and a terminal holding portion is placed on the other side of the ground plate. The capacitor terminal of the capacitor electrode is formed by integrally molding a part of the outflow hole to form a primary molded body, and is formed by a flat plate electrode and capacitor terminals protruding on both sides of the flat plate electrode. one side of the plate is passed through the remaining part of the insertion hole perpendicularly to the primary molded body, and the flat electrode is brought into close contact with the capacitor insulator, and the ground plate is connected from the flat electrode side, and the ground plate is connected to the holding part from the flat electrode side. A method for manufacturing a capacitor, which comprises integrally molding the projecting capacitor terminal through the resin outflow hole to form a secondary molded body in a predetermined shape. 2. The capacitor according to claim 1, wherein in forming the primary molded body, a flat plate electrode accommodating body consisting of a bottom portion in which the flat plate electrode can be accommodated and a peripheral wall portion is formed on one surface of the ground plate as the capacitor insulator. manufacturing method.