JPS6095915A - Variable porcelain condenser - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a small, high-quality chip-type variable ceramic capacitor used in various electronic devices.

Conventional structure and its problems A conventional variable magnetic capacitor of this type was constructed as shown in FIG.

That is, a stator electrode 6 is placed on the top surface of a stator substrate 4 made of a semicircular rotor electrode 2 or a vertical rotor electrode 2 on the top surface of a ceramic dielectric material 1 on a disk, and a bottom surface electrode 7 is placed on the bottom surface of a stator substrate 4 made of lumina or the like. . The adjusting shaft 11 is inserted through an insulating wire, and the lower end 12 of the adjusting shaft 11, which protrudes from the lower surface of the stator 9, is attached to a leaf spring 13, which connects the rotor 3. The head 1o of the adjustment shaft 11 was configured to be in pressure contact with the stator 9, and the head 1o of the adjustment shaft 11 was connected to the rotor electrode 2 with solder 14.

Conventionally, this type of variable magnetic capacitor was soldered to a printed circuit board by hand through the side electrode 6 and bottom electrode 7.8, but in recent years, it has been soldered to the printed circuit board using an automatic mounting machine. Therefore, chip-type variable ceramic capacitors that can be soldered using reflow ovens, hot air, and solder dips are required.
The variable ceramic capacitor shown in the figure had the following problems.

(1) Leaf spring 13 and upper end housing portion 12 of adjustment shaft 11
are arranged on the plane of the stator board 4, so when mounting and soldering to the printed circuit board, it was necessary to make a hole in the printed circuit board so that the leaf spring 13 and the like would not be hit.

(2) When the side electrodes 6 and the bottom electrodes 7 and 8 are soldered to the printed circuit board by solder dipping by direct immersion in a solder bath, the solder and fusix are attached to the head 1o of the adjustment shaft 11, the rotor electrode 2, and the stator electrode. It adheres to the surface of variable ceramic capacitors such as No. 5, impairing the appearance and performance, and making it impossible to satisfy the functions of variable ceramic capacitors.

OBJECTS OF THE INVENTION The present invention obviates these conventional drawbacks,
The purpose is to provide a variable ceramic capacitor that is excellent in terms of printed circuit board mounting and characteristics.

Structure of the Invention In order to achieve this object, the variable porcelain cocidenser of the present invention has a rotor terminal with a shaft and a stator terminal with a contact formed by bending the end, and a case made of a bottomed cylindrical insulator. The tips of the rotor terminal and stator terminal are drawn out from the outside of the case by insert molding at regular intervals, and bent along the side and bottom surfaces of the case to provide side electrodes and bottom electrodes. A stator having a stator electrode formed therein, a metal rotor having a rotor electrode formed therein, and a spring are disposed so as to pass through the shaft, and the contacts between the stator electrode and the stator terminal are electrically connected, and the metal rotor is rotatably arranged, the metal rotor and the dielectric are pressed into contact with each other by the sedge ring with the upper end of the shaft pressed, and a retainer is attached to the upper opening of the case in a sealed manner. be.

DESCRIPTION OF EMBODIMENTS The present invention will be explained below with reference to FIGS. 2 to 7 of one embodiment. First, in Fig. 2, 15 is shown in Fig. 3 ta+~(
The case is made of synthetic resin with excellent heat resistance and is formed into a bottomed cylindrical shape with a horseshoe-shaped hole, as shown in Fig. 4(a) and (b). Stator terminals 16 and rotor terminals 17 made of metal plates are insert-molded on the bottom side with a constant spacing between them. Contacts 18 and 19 are provided on both sides of one end of the stator terminal 16, and grooves 20 and 21 are provided at the bent ends of the stator terminal 16 and the rotor terminal 17 so that the bending process can be performed to a capacity. and 22゜2
3 is provided.

Further, a shaft 24 that is integral with the rotor terminal 17 is provided at the other end of the rotor terminal 17 by a drawing 9 process.

This shaft 24 has a rectangular outer shape and a hollow interior, and the upper end receiving portion 25 is closed.

That is, the stator terminal 16 and the rotor terminal 17 are the contact point 1.
8.19 and the shaft 24 are insert-molded into the case 15, and the hollow hole 26 of the shaft 24 is simultaneously filled with synthetic resin.

Further, the case 16 has an open top, and a step 2 lower than the height of the contacts 18 and 19 is formed on the bottom surface of the case 16.
7 is provided on the bottom surface, and grooves 28 and depressions 29, 30, 31 for orientation and positioning of the case 16 are provided on the bottom surface.
．． 32 are provided.

Here, the recesses 29 and 30 are recesses for positioning the stator terminal 16 and the rotor terminal 1 during insert molding.

Further, the recesses 31 and 32 are the contact points 18 of the stator terminals 16.
．． The recesses 31 and 32 are provided to prevent the insert portion at the lower part of the case 19 from being deformed, and the recesses 31 and 32 are for receiving the mold from the lower surface of the case 16.

At the tip portions 33, 34.35 of the stator terminal 16 and the tip portions 36, 37.38 of the rotor terminal 17, the tip portion 34.37 is bent upward to form a side electrode along the outside of the case 15, and the remaining portions are bent upward. Tip part 33,3
5, 36, and 38 are bent downward and further bent along the bottom surface of the case 16 to form a lower surface electrode.

Next, as shown in FIG. 5, the stator 39 is constructed by having a through hole 41 in the center of a horseshoe-shaped porcelain dielectric 40 and forming a stator electrode 42 on the lower surface by silver baking or the like.

In addition, the metal opening 43 has a circular through hole 44 in the center as shown in FIGS. ing.

A step 47 is provided on the lower surface of the metal rotor 43, and an adjustment groove 48 for rotating the metal rotor 43 and a recess 50 for inserting a spring 49, which will be described later, are provided on the upper surface.

As shown in FIGS. 7a and 7b, the spring is a plate spring in the shape of a round diaphragm 9, and has a rectangular through hole 51 in its center.

Next, the assembly structure will be explained with reference to FIG. 2. A rotor terminal 17 made of a synthetic resin material and having a shaft 24 drawn and stamped, and a stator terminal 16 having integrally provided contacts 18 and 19 are assembled by insert molding. Through the horseshoe-shaped upper opening of the case 15 made of 43 are rotatably fitted and stacked, and a spring 49 is further stacked in the recess 5o on the upper surface of the metal rotor 43.

The central through holes 41 and 44 of the stator 39 and the metal rotor 43 and the through hole 61 of the spring 49 are penetrated by a shaft 24 that is integrally formed with the rotor terminal 17 that is insert-molded in the case 15. The rectangular through hole 51 of 49 is fitted into the shaft 24, which has a rectangular outer shape, so as not to rotate.

Next, the upper end portion 26 of the shaft 24 is pinched, and the metal rotor 43 is
The stator 39 is held in place by the pressure of a spring 49.

As a result, the contacts 18 and 19 of the stator terminal (6) provided on the bottom of the case 16 are connected to the stator 39.

Here, when tightening the upper end portion 26 of the shaft 24, case 1
6. Use a jig or the like to make the inside of the depression 29.30 on the bottom surface of 6. Next, the upper surface 52 of the upper surface opening portion of the case 16 assembled as described above and the metal rotor 4 that is substantially flush with the upper surface 52 of the upper surface opening portion of the case 16 assembled as described above.
3, attach the protective sheet 64 to the top surface 53 of the case 16.
Close the top opening. This protective sheet 64 has a thickness of 60 mm.
A film 5 consisting of a plastic film + paper, etc. with a thickness of about 10 μm on a film-like double-sided adhesive 66 with a thickness of about μm
The adhesive 55 and film 56 have excellent heat resistance and do not cause problems such as melting even when directly immersed in a solder bath during soldering to a printed circuit board.

After soldering the side electrodes 34° 37 and the bottom electrodes 33, 36, 36.38 of the case 16 to the printed circuit board in this configuration, the protective sheet 54 affixed to the top surface of the case 16 and the metal rotor 43 is attached using an adjustment screwdriver. The adjustment screwdriver is inserted into the adjustment groove 48 of the metal rotor 43, and the metal rotor 43 is rotated to change the facing area of the rotor electrode 46 and the stator electrode 42 of the stator 39, thereby adjusting the capacitance. Do this. Since the spring 49 is fitted onto the shaft 24 so as not to rotate, the spring 49 does not rotate when the metal rotor 43 rotates.

For this reason, when the metal rotor 43 rotates, the lower surface flat part 57 of the spring 49 rubs against the lower surface of the insertion recess 6o of the spring 49 of the metal rotor 43, resulting in a large frictional surface and less wear due to rotation, making it possible to increase the rotational torque. , deterioration due to rotation is also reduced.

Effects of the Invention As described above, according to the variable magnetic capacitor of the present invention, the rotor terminal integrated with the shaft and the stator terminal integrated with the contact are insert-molded on the bottom of the case, and the shaft is inserted into the case. Assembly is easy because the tip of the rear shaft housing the stator, metal rotor, and spring is held in place by the spring pressure and clamped.

Further, since the spring is fitted to the shaft and the structure is such that the spring does not rotate when the metal rotor rotates, there is no wear due to rotation of the housing portion of the shaft, and mechanical characteristics such as rotational torque are stabilized.

The bottom and top of the case are completely sealed, and a heat-resistant protective sheet is attached to the case and the top of the case. Therefore, it is possible to perform dip soldering by directly immersing the device in a solder bath, and there is no problem such as deterioration of characteristics due to flux during soldering.

Since side electrodes are formed by bending part of the terminals of the rotor terminals and stator terminals in the case external drawer portion upward, the length of the side electrodes can be increased by three times the thickness of the case. Therefore, it is possible to reliably solder the printed circuit board, and it is possible to increase the mounting density of components on the printed circuit board.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing an example of a conventional variable magnetic capacitor, Fig. 2 is a cross-sectional view showing an embodiment of the variable magnetic capacitor of the present invention, and Fig. 3 (a), (b), and (C) are Figures 4(a) and (bl are a top view, cross-sectional view, and bottom view of the case part of the same capacitor, respectively, and (bl) are a plan view and cross-sectional view of the stator terminal and rotor terminal parts of the same capacitor, respectively, and Figure 5 is a top view of the case part of the same capacitor. A top view of the stator, Figures 6(a) and (b) are respectively a top view and a sectional view of the metal rotor of the same capacitor, and Figure 7(a) is a top view of the same capacitor. The figure is: 16... Case, 16... River/stator terminal, 1
7... Rotor terminal, 1B, 19... Contact, 24... Shaft, 26... Upper end scissors, 34.37...・Side electrode, 33.35,36
．． 38... Bottom electrode, 39... Stator, 4
2. Old... Stator electrode, 43. Mountain... Metal rotor, 4
5...Curved rotor electrode, 49...Spring, 6
4...Protection sheet. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 @3V4 #14 Figure 8 Figure 5

Claims (3)

[Claims] (1) A rotor terminal with an integrated shaft and a stator terminal with a contact formed by bending the end are insert-molded at regular intervals in a bottomed cylindrical insulator case. A stator and a rotor in which the tips of the rotor terminal and stator terminal are pulled out outside the case and bent along the side and bottom surfaces of the case to provide side electrodes and bottom electrodes, and four stay electrodes are formed inside the case. A metal rotor and a spring formed with electrodes are passed through the shaft, the stator and the spring are arranged so as not to be rotatable, and the contacts between the stator electrode and the stator terminal are electrically connected, and the metal rotor is rotatably provided. the upper end of the shaft is caulked to press the metal rotor and the dielectric body into pressure contact with each other by the spring; (2) Grooves are provided at the tips of the stator terminals and rotor terminals that are pulled out of the case, and a part is bent upward along the side of the case to serve as a side electrode, and the remaining part is bent downward to form a groove. The variable ceramic capacitor according to claim 1, which serves as a side electrode. (3) The variable ceramic capacitor according to claim 1, wherein the outer shape of the shaft provided integrally with the rotor terminal and the through hole of the spring are each formed into a rectangular shape and are fitted together so as not to rotate freely.