JPS618912A - Trimmer capacitor - 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 [Industrial Field of Application] The present invention relates to a trimmer capacitor used as an electronic circuit component.

[Prior Art] As a conventional trimmer capacitor, a cylindrical type shown in FIG. 5 is known. In the figure, 1 is an insulating cylinder made of a dielectric material such as ceramic, and 2 is one end of the insulating cylinder 1. A cylindrical fixed electrode 3 fitted on the outer periphery of the insulating cylinder 1 is arranged on the other end side of the insulating cylinder 1, and an adhesive 4 is attached to the insulating cylinder 1.
fixed by r: I! M (7)
m "6"'. Groove 5
The movable electrode 5 is a columnar movable electrode integrally having a head 5C having a diameter c1, and the threaded portion 5b of the movable electrode 5 is screwed into the female threaded portion 3b provided on the inner periphery of the terminal electrode 3. In order to set the required operating torque for rotating the movable electrode to a predetermined value, the end portion 3 of the portion of the terminal electrode 3 where the female screw 3b is provided.
A plurality of slots 3a extending in the axial direction are provided in the peripheral wall of b1, and the peripheral wall divided by the slots is narrowed inward in the radial direction, and the threaded portion 5b of the movable electrode 5 is connected to the slots 3a.
The terminal electrode 3 is screwed into the female threaded portion 3b of the terminal electrode 3 against the elasticity of the divided peripheral wall portion.

[Problems to be Solved by the Invention] As mentioned above, in conventional capacitors of this type, slots 3a were provided in the terminal electrodes in order to obtain the required operating torque of the movable electrodes, which made machining troublesome. Yes, also
Since it is necessary to secure a slot at the end of the terminal electrode in the axial direction, the end □m (D@HA Ka.11..,5
□, 1,7 There was a problem in that it became an obstacle to downsizing of the 1.7-gram capacitor.

Furthermore, in the conventional trimmer capacitor, after the terminal electrode 3 was positioned concentrically with respect to the insulating cylinder 1, the terminal electrode was fixed to the insulating cylinder 1 with adhesive 4, making it difficult to automate assembly.

As a result, manufacturing efficiency cannot be improved and costs are high.

In addition, in order to obtain linearity of capacitance in this type of trimmer capacitor, it is necessary to maintain a minute gap between the electrode part of the movable electrode and the insulating cylinder so that the electrode part does not come into contact with the inner surface of the insulating cylinder. However, in the conventional structure, it is extremely difficult to form a minute gap between the electrode part of the movable electrode and the insulating cylinder, and due to assembly variations, the electrode part of the movable electrode comes into contact with the insulating cylinder, resulting in poor linearity of capacitance. was often not available.

The object of the present invention is to be able to obtain a predetermined operating torque without providing slots in the terminal electrodes, and to easily assemble the terminal electrodes without positioning or gluing them. Our purpose is to provide trimmer capacitors.

[Means for Solving the Problems] The present invention provides an insulating cylinder made of a dielectric material, a cylindrical fixed electrode fitted on the outer periphery of the - end side of the insulating cylinder, and the other end of the insulating cylinder. a terminal electrode arranged on the side and fixed to the insulating cylinder; an electrode part inserted into the insulating cylinder and facing the fixed electrode through the insulating cylinder; and a screw having a male thread carved on the outer periphery. This trimmer capacitor is an improved trimmer capacitor including a columnar movable electrode screwed onto a female screw portion, the screw portion of which is electrically connected to the terminal electrode.

In the invention of Box 1, the terminal electrode is formed in the shape of a cylindrical body having an inner flange facing the other end surface of the insulating cylinder. and 2. of the movable electrode. A coiled member is provided which is wound with an inner diameter and a pitch that allows the threaded portion to be screwed into the coiled member, and the coiled member is fitted at a position adjacent to the inner flange portion on the inner periphery of the terminal electrode. The female screw portion is constituted by a shaped member. The insulating cylinder is press-fitted inside the terminal electrode and fixed to the terminal electrode, and the threaded portion of the movable electrode is screwed into the coiled member.

Further, in the invention of Box 2, in addition to the above configuration, the outer diameter of the electrode part of the movable electrode is set smaller than the inner diameter of the insulating cylinder, and the space between the electrode part and the threaded part is An enlarged diameter portion that contacts the inner circumference of the insulating cylinder is provided, and the electrode portion of the movable electrode is positioned concentrically with respect to the insulating cylinder by contact between the enlarged diameter portion of the movable electrode and the insulating cylinder. .

[Function of the Invention] With the above structure, the movable electrode is threadedly supported by the coiled member and electrically connected to the terminal electrode via the coiled member. Therefore, when the movable electrode is rotated, its electrode portion is displaced in the axial direction, and the opposing area between the electrode portion and the fixed electrode changes, resulting in a change in capacitance. In this case, by appropriately setting the inner diameter of the coiled member, the movable electrode can be easily provided with a predetermined required operating torque.

Therefore, there is no need to provide a slot in the terminal electrode, and the manufacturing of the terminal electrode can be simplified. Furthermore, since it is not necessary to provide a portion for forming a slot in the terminal electrode, the axial dimension of the terminal electrode can be reduced, and the trimmer capacitor can be made smaller.

In particular, according to the second invention, the enlarged diameter portion formed between the electrode portion and the screw portion of the movable electrode contacts the inner circumference of the insulating cylinder to position the electrode portion concentrically with respect to the insulating cylinder. So,
A minute gap can be maintained between the electrode part and the insulating cylinder so that the electrode part does not come into contact with the insulating cylinder, and linearity of capacitance can be easily obtained.

[Example] The present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows an embodiment of the present invention, in which 10 is a CK 6 i made of a dielectric material such as ceramic.
RRH, A8. f61iP] fm10(7)-$11
117)% A cylindrical fixed electrode 11 having a required axial dimension is fitted around the periphery. Fixed electrode 1
1 has an inner flange portion 11a at one end and a flange portion 11b at the other end, and is attached to the insulating cylinder 10 with the inner flange portion 11a in contact with the end surface on the one end side of the insulating cylinder 10. If the fixed electrode is formed into such a shape, the fixed electrode can be positioned at a predetermined position simply by press-fitting the insulating cylinder 10 into the inner periphery of the fixed electrode 11 and bringing its end surface into contact with the inner flange 11a of the fixed electrode. Since the fixed electrodes can be attached with a fixed electrode, the work of attaching the fixed electrodes becomes simple and automation of the attaching work becomes easy.

Reference numeral 12 denotes a terminal electrode formed in a cylindrical shape that tightly fits on the outer periphery of the other end of the insulating cylinder 10. In this embodiment, like the fixed electrode 11, this terminal electrode has an inner flange portion 12a and a flange portion 12b. It is formed in a shape having the following. A coiled member 13 formed by bending a conductive wire is fitted inside the terminal electrode 12, and this coiled member has a female threaded portion into which a threaded portion of a movable electrode (to be described later) is screwed. It is configured. This coiled member 13 is wound at least one turn or more so that its outline shape is similar to that of the terminal electrode 13.
It is desirable to form a polygon (a polygon larger than a quadrangle) or a circular shape inscribed in the cylindrical part, and the inner diameter and pitch P of the movable electrode can be screwed together with a predetermined tightness with the threaded part of the movable electrode described later. set to size. In this embodiment, as shown in FIG. 2, the coiled member 13 is formed to have a square outline. The coiled member 13 is inserted into the terminal electrode 12 to a position where it contacts the flange 12a, and the vertices of the four corners thereof touch the terminal electrode 12.
The terminal electrode is electrically connected to the inner periphery of the terminal electrode.

Reference numeral 14 denotes a substantially cylindrical movable type i inserted inside the insulating cylinder 10, and the movable electrode 14 has an outer diameter equal to the inner diameter of the insulating cylinder 10 so as to face the inner periphery of the insulating cylinder 10 with a minute gap Q therebetween. A cylindrical electrode portion 14 that is set smaller and faces the fixed electrode 11 via the insulating cylinder 10. a, a threaded part 14b with a male thread carved on the outer periphery, and a head 14c connected to the threaded part 14b, and a bit of an adjustment tool such as a screwdriver is inserted into the head 14c. A groove 14C1 is provided. Further, an enlarged diameter portion 14d having an outer diameter that slidably contacts the inner periphery of the insulating cylinder 10 is formed at the boundary between the electrode portion 14a and the threaded portion 14b of the movable electrode 14. When the portion 1/Id comes into contact with the inner periphery of the insulating cylinder 10, the electrode portion 14a is automatically positioned concentrically with respect to the insulating cylinder 10. Then, with the enlarged diameter portion 14d in contact with the inner periphery of the insulating cylinder 10, the inner periphery of the insulating cylinder 10 and the electrode portion 14
A predetermined minute gap q is formed between the electrode part 14a and the outer periphery of the insulating cylinder 10, so that the electrode part 14a does not come into contact with the inner periphery of the insulating cylinder 10.

The movable electrode 14 is inserted into the insulating cylinder 10 from one end side of the insulating cylinder 10, and its screw portion 14b is screwed into the coiled member 13. In this case, as shown in FIG. 3, the coiled member 13 comes into contact with the flank f of the threaded portion of the movable electrode 14, and as the movable electrode 14 rotates, it moves in the axial direction of the insulating cylinder 10. To spiral forward or backward.

In this case, the operating torque required to rotate the movable electrode can be arbitrarily set simply by appropriately setting the inner diameter of the coiled member 13. Therefore, it is necessary to provide a slot in the terminal electrode as in the conventional case.

The structure of the terminal electrode can be simplified and its manufacture can be facilitated. Further, the coiled member 13 can be attached by simply inserting it into the terminal electrode 12 to a position where it abuts the inner flange 12a. Furthermore, when connecting the terminal electrode and the insulating cylinder 10, it is sufficient to perform a simple operation of press-fitting the insulating cylinder 10 into the inner circumference of the terminal electrode 12. In this case, the depth of press-fitting is such that the end of the insulating cylinder 10 It is automatically regulated by coming into contact with the coiled member 13, and the coiled member 13 can be fixed at the same time by press-fitting the insulating cylinder 10 into the inner circumference of the terminal electrode 12, making it easy to automate the assembly work. It can be done.

The movable electrode 14 can be assembled by simply inserting it into an insulating cylinder and screwing its threaded part onto the coiled member 13, so the assembly can be automated. This is possible, and ultimately the structure of the present invention allows automation of the entire assembly process. Moreover, the movable electrode is formed by screwing the threaded portion 14b with the coil-shaped member, and by connecting the enlarged diameter portion 14d with the insulating cylinder 1.
Since the movable electrode is automatically positioned concentrically with respect to the insulating cylinder by contact with the inner circumference of the insulating cylinder, there is no need to align the movable electrode with the insulating cylinder, and the trimmer capacitor is free from center runout of the movable electrode. can be easily obtained.

In addition, as a result of being able to always reliably position the movable electrode 14 concentrically with respect to the insulating cylinder 10, a gap is reliably maintained between the electrode part 14a and the inner periphery of the insulating cylinder 10, and the electrode part can be moved into the insulating cylinder 10. Since it is possible to prevent the movable electrode from coming into contact with the peripheral wall portion of the trimmer capacitor 10, it is possible to prevent the center runout of the movable electrode and to ensure the linearity of the capacitance, thereby improving the quality of the trimmer capacitor.

In the above embodiment, the terminal electrode 12 and the fixed electrode 11
The same parts can be used for , and in this way,
The above-mentioned trimmer capacitor, which can reduce the number of types of parts and facilitate management of the manufacturing process, is, for example, as shown in FIG. The fixed electrode section 11 is connected to an electrode section provided on a printed circuit board by soldering. In this case, the flange portion 11b of the fixed electrode 11 comes into contact with the substrate 15 and the trimmer capacitor is automatically positioned, making it easy to automate the mounting of components onto the substrate. It is of course possible to attach the trimmer capacitor to the substrate or the like on the terminal electrode 12 side.

In the above embodiment, the outline shape of the coiled member 13 is square, but the coiled member may have any shape as long as it is inscribed in the terminal electrode.
As shown in the figure, a coiled member 13 having a regular hexagonal outline may be used. In order to ensure the electrical connection between the coiled member and the terminal electrode, it is recommended that the outline of the coiled member be formed into a polygonal shape that is inscribed in the terminal and child electrodes (the apex is always in contact with the terminal electrode). It's advantageous.

In order to obtain linearity of capacitance, it is necessary to provide the enlarged diameter portion 14d in the movable electrode 14 as in the above embodiment to maintain a minute gap between the electrode portion 14a and the inner periphery of the insulating cylinder 10. However, if linearity of capacity is not required, the enlarged diameter portion 14. d is omitted and the electrode part 14a is replaced by the insulating cylinder 1.
It is also possible to make it contact with the inner circumferential surface of 0.

[Effects of the Invention] As described above, according to the present invention, since the female threaded portion into which the threaded portion of the movable electrode is screwed is formed by the coiled member fitted inside the terminal electrode, the inner diameter of the coiled member is The required operating torque of the movable electrode can be arbitrarily set by simply setting .

Therefore, there is no need to provide a slot in the terminal electrode, and the axial dimension of the terminal electrode can be reduced, thereby making it possible to downsize the trimmer capacitor. Further, since the insulating cylinder is fixed by being press-fitted into the terminal electrode, assembly can be facilitated, and there is an advantage that the assembly of the trimmer capacitor can be automated and manufacturing efficiency can be improved.

In particular, according to the second invention of the present application, the movable electrode is positioned concentrically with respect to the insulating cylinder by the screwing of the threaded part of the movable electrode and the coiled member and the contact between the enlarged diameter part of the movable electrode and the insulating cylinder. This eliminates curling of the movable electrode, and the enlarged diameter portion of the movable electrode allows the electrode portion of the movable electrode to be positioned so as not to come into contact with the insulating cylinder. This has the advantage that linearity of capacitance can be obtained with respect to the capacitance, and that a trimmer capacitor of excellent quality can be easily obtained.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention, FIG. 2 is a sectional view taken along the line ■-■ in FIG. FIG. 4 is a sectional view similar to FIG. 2 showing a modified example of the coiled member used in the present invention, and FIG. 5 is an example of a conventional trimmer capacitor. FIG. 10... Insulated cylinder, 11... Fixed electrode, 12...
Terminal electrode, 13... Coiled member, 14... Movable electrode, 1F 4a... Electrode part, 14b... Screw part, 14d...
Expanded diameter section.

Claims (2)

[Claims] (1) An insulating cylinder made of a dielectric material, a cylindrical fixed electrode fitted on the outer periphery of one end of the insulating cylinder, and a fixed electrode arranged on the other end of the insulating cylinder and fixed to the insulating cylinder. A terminal electrode, an electrode part that is inserted into the insulating cylinder and faces the fixed electrode through the insulating cylinder, and a threaded part with a male thread carved on the outer periphery are integrally formed. In the trimmer capacitor, the trimmer capacitor includes a columnar movable electrode that is screwed onto a female screw portion that is electrically connected to a terminal electrode, and the terminal electrode has an inner flange portion that faces the other end side end surface of the insulating cylinder. A coiled member formed in the shape of a cylindrical body and wound with an inner diameter and pitch that allows the threaded portion of the movable electrode to be screwed is located at a position adjacent to the inner flange portion on the inner periphery of the terminal electrode. When fitted, the coiled member constitutes the female screw portion, the insulating cylinder is press-fitted and fixed inside the terminal electrode, and the threaded portion of the movable electrode is screwed into the coiled member. A trimmer capacitor characterized by: (2) an insulating cylinder made of a dielectric material, a cylindrical fixed electrode fitted on the outer periphery of one end of the insulating cylinder, and a fixed electrode arranged on the other end of the insulating cylinder and fixed to the insulating cylinder. A terminal electrode, an electrode part that is inserted into the insulating cylinder and faces the fixed electrode through the insulating cylinder, and a threaded part with a male thread carved on the outer periphery are integrally formed. In the trimmer capacitor, the trimmer capacitor includes a columnar movable electrode that is screwed onto a female screw portion that is electrically connected to a terminal electrode, and the terminal electrode has an inner flange portion that faces the other end side end surface of the insulating cylinder. A coiled member formed in the shape of a cylindrical body and wound with an inner diameter and pitch that allows the screw portion of the movable electrode to be screwed into the coil member is fitted into a position adjacent to the inner flange portion on the inner periphery of the terminal electrode. The coiled member constitutes the female threaded portion, the insulating cylinder is press-fitted and fixed inside the terminal electrode, the threaded portion of the movable electrode is screwed into the coiled member, and the movable The outer diameter of the electrode part of the electrode is set smaller than the inner diameter of the insulating cylinder, and an enlarged diameter part that contacts the inner circumference of the insulating cylinder is provided between the electrode part and the threaded part, and the movable electrode is enlarged. A trimmer capacitor characterized in that the electrode portion of the movable electrode is positioned concentrically with respect to the insulating cylinder by contact between the diameter portion and the insulating cylinder.