JPH0576166B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a capacitor and a method for manufacturing the same, and particularly to a capacitor applied to a filter for preventing noise leakage and a method for manufacturing the same.

[Background technology]

In general, a magnetron generates high-frequency energy from its oscillating unit body, and outputs it to a high-frequency 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 impact on

The capacitor used in this noise leakage prevention filter was also disclosed in Utility Application No. 1-67140.
The manufacturing method was proposed in Japanese Patent Application No. 1-136684.

Figures 5a and 5b, 6 and 7 show the capacitor and its manufacturing method. In its manufacturing method, a galvanized iron plate with a thickness of 0.6 to 1.0 mm is press-formed, and a grounding hole 11 is formed.
Then, a ground plate 10 having a length of 36 mm and a width of 63 mm is formed, which has a fixing hole 12, a pair of insertion holes 13 having a length of 10.3 mm and a width of 4.5 mm, and a pair of resin outflow holes 14 having an inner diameter of 3.6 mm. 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
20 to 30% glass fiber was applied to both sides of the ground plate 10 under conditions of injection pressure of 48 to 55 Kg/cm ² , molding (cooling) time of 6 to 10 seconds, and mold temperature of 50 to 55°C. Primary molded body 30 made of PBT resin mixed in weight ratio
is formed by molding. That is, on one surface of the ground plate 10, there is a bottom part 31 having a thickness of 1.2±0.01 mm and having projections 35 arranged above and below the center thereof, and a peripheral wall part 3 rising from the bottom part 31 by a predetermined dimension.
2, and as shown in FIG. Further, a fixing protrusion 36 is formed to integrate the flat electrode housing 40 through the fixing hole 12 of the ground plate 10. 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 33 and a resin outflow hole 34 are formed in a state where the two are communicated through a portion of the hole.
Then, a nickel-plated iron plate with a thickness of 0.8 mm was press-formed in advance to form a terminal 21 for the power supply side capacitor with a width of 6 mm and a length of 30 mm, with an intersection of 3.0 mm and a length of 14 mm.
The terminal 23 for the capacitor on the side of the yoke coil is
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 about 25 mm both horizontally and horizontally, is inserted into the insertion hole 33, and the protruding bodies 24 and 25 of the flat plate electrode 22 are inserted into the flat plate electrode housing. The flat electrodes 22 are brought into contact with the bottom 31 of the body 40 so as to be engaged with both sides of the placement protrusions 35 formed on the bottom 31 of the body 40 . Next, the flat electrode housing 40
The flat plate electrode 22 of the capacitor electrode 20 is placed inside the cavity of the molding die, and the injection pressure is 30 to 35 kg/cm ² to form the oval body 38 and the power supply side capacitor terminal 21 protruding from it. A secondary molded body 50 made of the same material as the primary molded body 30 is formed by molding so as to cover the plate electrode 22 disposed in the flat electrode housing 40 and to fix the flat plate electrode 22 disposed in the flat electrode housing 40 (FIG. 7a, b). That is,
A mold body having 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 an oval body 38 and a part of the power supply side capacitor terminal 21 protruding from the oval body 38. 60, and an electrode fixing part 51 is formed on a part of the surface of the flat plate electrode 22 so as to be integrated with the mold body 60 through the resin outflow hole 34 formed in the primary molded body 30. Fix it. 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. A groove 37 is formed in the oval body 38 in order to improve the engagement of the secondary molded body 50.

[Problem to be solved by the invention]

However, this capacitor has the following problems.

(1) If force is applied to the ground plate or the ground plate is deformed during installation and fixation, the ground plate may be damaged even though the capacitor insulator, oval body, fixing protrusion, etc. are provided to sandwich the ground plate. Because the adhesion to the capacitor insulator is weak, the capacitor insulator may separate from the ground plate around its peripheral wall.
This separation causes variations in capacitance and degrades quality.

(2) When molding the electrode fixing part that fixes the capacitor terminal on the chiyoke coil side, the molding material may flow between the capacitor insulator and the flat plate electrode, so the distance between the ground plate and the flat plate electrode changes. This variation also causes variations in capacitance.

Furthermore, the method for manufacturing a capacitor described above has the following problems.

(1) In order to mold the capacitor insulator to a uniform thickness without leaving molding distortion inside, the capacitor insulator is removed from the mold after it has completely cooled. Therefore, molding time becomes longer and productivity decreases.

(2) Since there are primary and secondary molding processes, productivity is further reduced.

(3) Since primary and secondary molds are required, equipment costs are high, leading to higher product costs.

Therefore, an object of the present invention is to provide a capacitor with stable quality and less variation in capacitance.

Another object of the present invention is to provide a method for manufacturing a capacitor that has high productivity and can reduce equipment costs.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a capacitor and a method for manufacturing the same as described below.

That is, the capacitor of the present invention has the following means.

(1) Metal grounding plate This is made of galvanized iron plate, etc., and serves as the grounding electrode for a pair of capacitor electrodes. An insertion hole through which the first capacitor terminal, which becomes a terminal on the power supply side or the load side, is inserted, an outflow hole through which molding resin flows out, and an insulator for the capacitor are strengthened, and the plate itself It has multiple recesses to strengthen it.

(2) Molded body Contains a capacitor insulator and a capacitor terminal holding part. A capacitor insulator is molded to a predetermined thickness on the first surface of the metal ground plate, and a through hole is formed through which the first capacitor terminal passes. The capacitor terminal holding portion is provided on the second surface of the metal grounding plate, and is integrally molded with the capacitor insulator through a portion of the insertion hole and the outflow hole.

(3) Capacitor electrode A capacitor electrode forms a predetermined capacitance between the capacitor electrode and the ground plate, and has an electrode portion and a terminal portion. The electrode part faces the metal grounding plate through the capacitor insulator, and the terminal part, which is made of a flat metal plate having a fixing opening in a part thereof, extends from the electrode part to both sides. The first capacitor terminal and the second capacitor terminal are protruded, and the first capacitor terminal is passed through the capacitor insulator and the through hole of the capacitor terminal holding portion.

(4) Electrode fixing piece Formed as a separate member from the capacitor insulator. It has a through hole that abuts a part of the capacitor insulator and the capacitor electrode, through which the second capacitor terminal passes, and is made of a material that can be joined to the molded body. The second capacitor terminal is passed through the through hole and connected to the capacitor insulator through the fixing opening of the capacitor electrode.

(5) Terminal fixing piece Like the electrode fixing piece, it is formed as a separate member from the capacitor insulator. It has a through hole through which the first capacitor terminal passes, and is made of a material that can be joined to the molded body. The first capacitor terminal is passed through the through hole and joined to the capacitor terminal holding portion.

Further, the method for manufacturing a capacitor of the present invention includes the following means.

(1) Formation of capacitor terminal holding part A capacitor insulator having a through hole through which the first capacitor terminal passes is molded to a predetermined thickness on the first surface of the grounding plate, and
By this molding, a through hole is formed on the second surface of the ground plate, which is integrated with the capacitor insulator through the through hole and a part of the outflow hole, and through which the first capacitor terminal passes. form a capacitor terminal holding part.

(2) Arrangement of capacitor electrode The first capacitor terminal of the capacitor electrode is passed through the capacitor insulator and the through hole of the capacitor terminal holding portion, so that the electrode portion is brought into close contact with the capacitor insulator. Place the capacitor electrodes.

(3) Formation of electrode fixing piece An electrode fixing piece having a through hole through which the second capacitor terminal passes is formed from a material that can be bonded to the capacitor insulator.

(4) Joining the electrode fixing piece Fix the electrode to the capacitor insulator through the fixing opening of the capacitor electrode with the second capacitor terminal passing through the electrode fixing piece's through hole. Join the pieces.

(5) Formation of terminal fixing piece A terminal fixing piece having a through hole through which the first capacitor terminal passes is formed from a material that can be joined to the capacitor terminal holding portion.

(6) Joining the terminal fixing piece The terminal fixing piece is joined to the capacitor terminal holding portion with the first capacitor terminal passing through the through hole thereof.

The means (1) to (6) described above do not restrict the order of the steps in the capacitor manufacturing method of the present invention. For example, the formation of the electrode fixing piece and the terminal fixing piece is Although it is preferable to use the same mold during molding, it may be performed in a separate process before that, and furthermore, the electrode fixing piece and the terminal fixing piece may be joined at the same time.

[Effect]

The capacitor insulator formed on the first surface of the metal ground plate is sandwiched between the electrode portion of the capacitor electrode and the metal ground plate, and these three form a one-end grounded capacitor. The capacitance of a capacitor is determined by the area and spacing of the opposing electrodes, and the dielectric constant of the insulator. To provide a capacitor with little variation in capacitance. Even if the thickness of the capacitor insulator is uniform, variations in the spacing between the electrodes will cause the capacitance to vary. To prevent this, secondary molding, which could cause molding material to flow between the electrode and the capacitor insulator, is omitted. This omission is made possible by joining the electrode fixing piece and the terminal fixing piece. The electrode fixing piece and the terminal fixing piece can be made at the same time as the molding of the capacitor insulator.
Capacitors can be manufactured without multiple molding operations. Since there is no secondary molding work, there is more time available for molding the capacitor insulator. This facilitates the molding of a capacitor insulator without internal distortion. Omitting the secondary molding operation not only prevents the above-mentioned variation in the distance between the electrodes, but also shortens manufacturing time and reduces the number of molds.

〔Example〕

Hereinafter, the capacitor of the present invention and its manufacturing method will be explained in detail.

1a, b, c and 2 a, b show a capacitor of the present invention, in which a plurality of linear recesses 115
Terminal fixing piece 1 sandwiching the ground plate 110 formed with
60 and a peripheral wall portion 132 are provided. An oblong body 138 molded integrally with the peripheral wall 132 is located inside the terminal fixing piece 160, and a protrusion 1 that fits into the recess 115 is provided at the base of the peripheral wall 132.
43 is formed. A capacitor electrode 120 is in surface contact with the base of the oval body 138, and a first capacitor terminal 121 and a second capacitor terminal 123 integrally formed with the capacitor electrode 120 protrude from both sides of the ground plate 110. . The ground plate 110 has a mounting hole 111, and
A fixing projection 136 integrally formed with the peripheral wall portion 132 projects from the opposite side thereof. The base of the second capacitor terminal 123 is fixed with an electrode fixing piece 150.

The structure of the capacitor of the present invention has been briefly described above, and will be described in more detail below by explaining its constituent parts with reference to FIG. 3 and then explaining its manufacturing method.

The ground plate 110 has a resin outflow hole 114 between the insertion holes 113 and fixing holes 1 with an inner diameter of about 5 mm on both sides.
12, with a width of approximately 1.5 mm and a depth of approximately 0.5 mm on one side.
A plurality of front and rear recesses 115 are formed. A capacitor insulator 131 is formed on one surface of the grounding plate 110, an insertion hole 133 for a capacitor terminal is provided at the bottom of the insulator 131, and a substantially square electrode fixing piece joint 141 protrudes from the bottom between the capacitor and the capacitor. form. This joint 141 has flat electrode arrangement protrusions 135 on the top and bottom thereof, and grooves 142 on the surface of the joint.
Furthermore, a recess 11 of the ground plate 110 is formed at the bottom of the peripheral wall 132 of the capacitor insulator 131.
Insulating protrusions 143 filled with 5 are formed, respectively. The other surface of the grounding plate 110 is integrated with a capacitor insulator to form an oval body 138, and the oval body 138 has an insertion wall 144 formed with an insertion hole 133 through which a capacitor terminal is inserted, and a pair of insertion walls 144. A joining protrusion 145 is erected with a predetermined length from the bottom surface of the oval body, and a groove 137 is further formed. Electrode fixing piece 15 joined to electrode fixing piece joining part 141
0 is a substantially rectangular flat plate, which has a fitting through hole 151 into which a pair of capacitor terminals 123 are fitted, and a fitting through hole peripheral wall 152 configured by making the fitting through hole 151 protrude from the flat plate, and has a fitting through hole 152 on the other side. is the electrode fixing piece joint 14
1 has a protrusion 153 that increases the bonding area to increase the bonding strength. The terminal fixing piece 160 is the oval body 138 of the molded body described above.
An oblong body 1 that is fitted, covered and joined to
It is formed into an elliptical shape having recesses (not shown) that fit into the insertion wall 144 and the joint protrusion 145 of 38, and a protrusion (not shown) that fits into the elliptical body 138 and the groove 137. ing. The other surface of the terminal fixing piece 160 has a protrusion 163 and a peripheral wall 164 having a fitting hole 162 into which a pair of capacitor terminals are fitted from the bottom 161 .

In manufacturing capacitors, the first step is to reduce the thickness to 0.6
A ground plate 110 having a plurality of recesses 115 is prepared by press-forming a galvanized iron plate having a diameter of 1 mm. The electrode fixing piece 150 and the terminal fixing piece 160 are simultaneously molded as separate bodies using a single molding die when molding a molded body (oblong body 138, etc.). In order to strengthen the bond between this molded body and both fixing pieces 150, 160, the glass fiber mixing ratio of the molding resin is changed. At this time, they may be molded separately. However, simultaneous molding is preferable from the viewpoint of reducing the number of molds, molding steps, etc. Through this molding, the recess 115 of the ground plate 110 is filled with the insulating protrusion 143 of the molded body, and the electrode fixing piece joint 141 is formed. Next, the flat electrode 120 is inserted. That is, the ground plate 1
The capacitor terminals 121 of the pair of capacitor flat plate electrodes 120 are inserted into the insertion holes 133 from the capacitor insulator 131 side of the molded body molded on both sides of the molded body 10, and the flat plate electrodes 120 are brought into contact with the insulator 131. The flat electrode 120 is held by the peripheral wall portion 132, the electrode fixing piece joint portion 141, and the flat electrode arrangement protrusion 135. At this time, the capacitor terminal 121 protrudes from the insertion hole 133 of the oval body 138 formed on the back surface of the ground plate.
When the flat electrode 120 comes into contact with the insulator 131, the electrode fixing piece joint 141 contacts the protrusion 12 of the electrode 120.
4,125, and its surface slightly protrudes from the electrode 120 surface. After this, the electrode fixing piece 15
0. Join the terminal fixing piece 160. That is, after inserting the capacitor electrode 120 into the molded body, the electrode fixing piece 150 is fitted into the capacitor terminal 123, and the terminal fixing piece 160 is fitted into the capacitor terminal 121 protruding from the oblong body 138, respectively. At this time, the electrode fixing piece joint part 1 of the molded body
41, one side of the electrode fixing piece 150 is brought into contact with the terminal fixing piece 160, and the oval body 138 is covered with the terminal fixing piece 160. In this state, ultrasonic waves adapted to the respective shapes are applied from both sides of the electrode fixing piece 150 side and the terminal fixing piece 160 side. A horn (not shown) can be brought into contact with it. Ultrasonic horn is 20~
At a vibration frequency of 40KHz, vibrations with a vibration width of 30 to 40μm can be applied. Due to the mechanical vibration, both pieces 15
0,160, the joint part 141 of the molded body, and the surface of the oval body 138 generate heat, and the pressure applied by the horn causes the electrode fixing piece 150 to join the joint part 141.
First, the terminal fixing pieces 160 are respectively joined to the oval bodies 138, and the electrodes 120 are fixed. In this example, the output is as an ultrasonic plastic welder.
Use 1200W, application time 2-3 seconds, pressure 5
It was made to join by ~6Kg/ ^mm2 .

On the other hand, FIGS. 4a and 4b show an example in which the electrode fixing piece 150 and the terminal fixing piece 160 are joined in separate steps. The oval shaped body 138 and the capacitor terminal 121 protruding through it are inserted into a metal pedestal 180 having an inner shape corresponding to their outer shape, and this pedestal 180 and the capacitor terminal It has 123 relief holes 171 and an electrode fixing piece 180.
The electrode fixing piece 150 is held between the ultrasonic horns 170A having a shape suitable for the above, and the electrode fixing piece 150 is welded to the electrode fixing piece joining part 141 by the heat generated by ultrasonic vibration of the horn 170A. The protrusion 153 of the electrode fixing piece 150 and the groove 142 of the electrode fixing piece joining part 141 serve to increase heat generation due to vibration and to increase the bonding strength by increasing the bonding area. After that, a terminal fixing piece 160 is attached to the capacitor terminal 121 and the oval body 138 through which this terminal 121 is inserted and protrudes.
The horn 170B is brought into contact with the outer periphery of the electrode, and one side of the fixed electrode that was joined earlier is inserted into the pedestal 181, and ultrasonic vibration is applied to weld the electrode. In the above ultrasonic welding, glass fiber is mixed into the molded object, etc., but if the amount of glass fiber mixed exceeds 30% by weight, the welding force will decrease by 30% compared to when it is not included. Data is available.
To prevent this, a hot melt adhesive can also be used.

〔Effect of the invention〕

According to the capacitor and manufacturing method thereof of the present invention described above, the following effects can be obtained.

(1) Since multiple recesses are provided in the ground plate, the strength can be increased without increasing the thickness of the ground plate.

(2) Since the ground plate is provided with a recess to increase its strength, it will not be deformed by the molding pressure of the compact.

(3) Since the concave part of the ground plate is filled with the molded resin of the molded body, the adhesion between the ground plate and the capacitor insulator of the molded body is strengthened.

(4) Since the molded body is molded while filling the molded resin into the concave portion of the ground plate, molding distortion and deformation of the capacitor insulator are eliminated.

(5) Since the electrode fixing piece on the flat plate electrode is welded to the molded body by ultrasonic vibration, the capacitor insulator and the flat plate electrode are in close contact, the distance between the ground plate and the flat plate is uniform, and the thickness of the capacitor insulator is can be made uniform.

(6) Molded object, electrode fixing piece,
Since the terminal fixing pieces can be individually molded, the number of molding steps is reduced.

(7) Since secondary molding is not required, molding man-hours are shortened.

the result, (1) The mechanical strength of the capacitor increases.

(2) Electrical characteristics such as capacitance of the capacitor are stabilized.

(3) Capacitor productivity improves.

(4) The cost of capacitors is reduced.

[Brief explanation of the drawing]

Figures 1a, b, and c are a front view, a top view, and a back view showing one embodiment of the capacitor of the present invention, and Figures 1 and 2 are
Figures a, b are sectional views taken along lines A-A and B-B in Figures 1 a, b, and c; Figures 3 a, b, and c are exploded views showing each member in the manufacturing process of the capacitor of the present invention; Figures 4a and 4b are cross-sectional views showing the ultrasonic welding method in the manufacturing process of the capacitor of the present invention;
Figures a and b are exploded views showing each component in the manufacturing process of the previously proposed capacitor, Figure 6 is a perspective view of the previously proposed capacitor, and Figures 7 a and b are the previously proposed capacitors. A cross-sectional view showing a capacitor. Explanation of symbols, 110...Ground plate, 112...Fixing hole, 113...Insertion hole, 114...Resin outflow hole, 115...Recess, 120...Flat electrode, 12
1...First capacitor terminal, 123...Second
capacitor terminal, 124, 125... protruding body, 131... insulator for capacitor, 132...
... Peripheral wall portion, 133 ... Insertion hole, 136 ... Projection, 137 ... Groove, 138 ... Oval body, 141
...Electrode fixing piece joint, 142...Groove, 143...
... Insulating projection, 144 ... Insertion groove, 145 ... Connection projection, 150 ... Electrode fixing piece, 152 ... Insertion hole peripheral wall, 153 ... Protrusion, 160 ... Terminal fixing piece,
161...bottom, 162...fitting hole, 163...protrusion, 164...peripheral wall, 170A, 170B...
Ultrasonic welding horn, 180, 181...cradle.

Claims (1)

[Scope of Claims] 1. A flat metal grounding plate having an insertion hole through which a first capacitor terminal is inserted and an outflow hole through which molding resin flows out; a capacitor insulator having a thickness that includes a through hole through which the first capacitor terminal passes; and a capacitor insulator that is provided on the second surface of the metal plate through a portion of the through hole and the outflow hole. a molded body integrally formed with a capacitor terminal holding portion having a through hole through which the first capacitor terminal passes; and a molded body that faces the metal ground plate via the capacitor insulator and is fixed to a part thereof a flat electrode portion having an opening for the capacitor, and a terminal portion protruding from the electrode portion to both sides and consisting of the first capacitor terminal and the second capacitor terminal, and the first capacitor terminal is connected to the capacitor terminal. a capacitor electrode that penetrates through the through hole of the capacitor insulator and the capacitor terminal holding part; and a through hole that abuts a part of the capacitor insulator and the capacitor electrode and that the second capacitor terminal passes through. , an electrode fixing piece that has the second capacitor terminal passed through the through hole and is joined to the capacitor insulator through the fixing opening of the capacitor electrode; and a through hole that the first capacitor terminal passes through. A capacitor comprising a terminal fixing piece having a through hole through which the first capacitor terminal passes and is joined to the capacitor terminal holding portion. 2. The capacitor according to claim 1, wherein the molded body, the electrode fixing piece, and the terminal fixing piece are made of the same molding material containing a predetermined amount of glass fiber. 3. The metal ground plate has a fixing hole that strengthens integration with the capacitor insulator, and a recess that strengthens the strength of the ground plate itself, and the fixing hole and the recess have an insulating resin that constitutes the capacitor insulator. The capacitor according to claim 1, wherein the capacitor is filled with. 4 A capacitor insulator having a through hole through which a capacitor terminal passes through a first surface of a flat ground plate having a capacitor terminal insertion hole and a resin outflow hole, and a capacitor insulator having a through hole through which a capacitor terminal passes through the second surface of the ground plate. A capacitor terminal holding part which is integrated with the capacitor insulator through the outflow hole and has a through hole through which the capacitor terminal passes is molded at the same time, and a flat plate electrode and a first part protruding to both sides of the flat plate electrode are molded together.
A first capacitor terminal of a capacitor electrode having a capacitor terminal and a second capacitor terminal is penetrated through the through hole of the capacitor insulator and the capacitor terminal holding part, and the flat plate electrode is brought into contact with the capacitor insulator, forming an electrode fixing piece having a through hole through which the second capacitor terminal passes, and a terminal fixing piece having a through hole through which the first capacitor terminal passes, from a material that can be joined to an insulator and a holding part; A method for manufacturing a capacitor, characterized in that first and second capacitor terminals are passed through each of the through holes, the electrode fixing piece is joined to a capacitor insulator, and the terminal fixing piece is joined to a capacitor terminal holding part. . 5. The method of manufacturing a capacitor according to claim 4, wherein the capacitor insulator, the capacitor terminal holder, the electrode fixing piece, and the terminal fixing piece are molded at the same time using the same mold. 6. The method of manufacturing a capacitor according to claim 4, wherein the electrode fixing piece and the terminal fixing piece are joined by ultrasonic welding.