阅读说明：本技术 一种薄膜电容器盖子、薄膜电容器及其制造方法 (Thin film capacitor cover, thin film capacitor and manufacturing method thereof ) 是由 陈建强 于 2019-09-09 设计创作，主要内容包括：一种薄膜电容器盖子,包括：电容器盖子的侧边缘上设置有多个限位块,多个限位块的外边缘形成的图形的中心线与电容器盖子的中心轴线重合,多个限位块可与电容器外壳内壁接触,以确保电容器盖子的中心轴线与电容器外壳的中心轴线重合。本发明的薄膜电容器通过在电容器盖子的四周设置防爆块,增加电容器盖子的固定结构或结构刚性,电容器盖子四周的防爆块与电容器外壳贴合紧密,进而保证电容器盖子与电容器外壳贴合紧密,最终使制造的薄膜电容器具有更优良的电容封口质量。(A thin film capacitor cover comprising: the side edge of the capacitor cover is provided with a plurality of limiting blocks, the central line of a graph formed by the outer edges of the limiting blocks coincides with the central axis of the capacitor cover, and the limiting blocks can be in contact with the inner wall of the capacitor shell to ensure that the central axis of the capacitor cover coincides with the central axis of the capacitor shell. According to the film capacitor, the explosion-proof blocks are arranged on the periphery of the capacitor cover, so that the fixing structure or structural rigidity of the capacitor cover is improved, the explosion-proof blocks on the periphery of the capacitor cover are tightly attached to the capacitor shell, the capacitor cover is further tightly attached to the capacitor shell, and finally the manufactured film capacitor has better capacitor sealing quality.)

1. A thin film capacitor cover, comprising: be provided with a plurality of stoppers on the side edge of condenser lid, the central line of the figure that the outward flange of a plurality of stoppers formed coincides with the central axis of condenser lid, and a plurality of stoppers all contact with the condenser shell inner wall to ensure the central axis of condenser lid and the coincidence of condenser shell's central axis.

2. A film capacitor in accordance with claim 1, wherein the capacitor cover has an explosion-proof block, and a plurality of stopper pieces are provided on side edges of the explosion-proof block.

3. A film capacitor as claimed in claim 1 or 2, wherein the number of the stopper is at least 3.

4. A film capacitor as claimed in claim 1 or 2, wherein the plurality of stoppers are provided in an even number and are disposed at side edges of the explosion-proof block symmetrically with respect to a central axis of the capacitor cover.

5. The film capacitor of claim 2, wherein the stopper is sized to cover the entire thickness of the explosion proof mass.

6. A film capacitor as claimed in claim 1 or 2, wherein the stopper has a curved contact surface including an arc surface and a flat surface and an inclined mounting surface having a thickness smaller than that of the curved contact surface, the curved contact surface being in contact with an inner wall of the capacitor case.

7. The film capacitor of claim 2, wherein the stopper and the explosion-proof piece are made of the same material.

8. A film capacitor as claimed in claim 1 or 2, characterized in that the capacitor cover is round or square.

9. A film capacitor, characterized in that it comprises a capacitor cover according to any one of claims 1-8.

10. The film capacitor of claim 9, wherein the capacitor cap comprises an explosion proof block, a connection cover plate and a copper foil, and the explosion proof block, the connection cover plate and the copper foil are of an integrally formed structure.

11. A method of manufacturing a thin film capacitor, comprising the steps of: a plurality of limiting blocks are arranged on the side edge of the explosion-proof block of the capacitor cover, and the central line of a graph formed by the outer edges of the limiting blocks is superposed with the central axis of the capacitor cover; installing a capacitor cover provided with a plurality of limiting blocks on a capacitor shell which is filled with fillers to perform pressing operation; and sealing the capacitor which is pressed down by using a sealing machine.

Technical Field

The invention belongs to the technical field of capacitors, and particularly relates to a metalized film capacitor and a manufacturing method thereof.

Background

The film capacitor has a structure in which a metal foil is used as an electrode, and a plastic film such as polyethylene, polypropylene, polystyrene, or polycarbonate is stacked from both ends and wound into a cylindrical shape. The plastic film is also called a poly (ethyl ester) capacitor (also called a Mylar) capacitor, a polypropylene capacitor (also called a PP capacitor), a polystyrene capacitor (also called a PS capacitor) and a polycarbonate capacitor, respectively, depending on the type of the plastic film.

The metallized film capacitor is formed by evaporating a layer of metal film on the surface of a polyester film to replace a metal foil as an electrode, and the volume of the metallized film layer after being wound is much smaller than that of a metal foil capacitor because the thickness of the metallized film layer is far smaller than that of the metal foil. The greatest advantage of metallized film capacitors is the "self-healing" characteristic. The self-healing characteristic is that if the film medium has a defect at a certain point and has a breakdown short circuit under the action of overvoltage, the metallized layer of the breakdown point can be instantly melted and evaporated under the action of electric arc to form a small metal-free area, so that two pole pieces of the capacitor are insulated from each other again and can still work, thereby greatly improving the working reliability of the capacitor. Analysis is conducted on the principle that the metallized film capacitor does not have a short-circuit failure mode, and a plurality of short-circuit failures occur in the metal foil capacitor.

The metallized film capacitor is produced by vacuum vapor plating a thin metal layer on a plastic film as an electrode. Thus, the thickness of the electrode foil can be omitted, and the volume of the capacitor per unit capacity can be reduced, so that the thin film capacitor can be easily made into a small-sized capacitor with large capacity. For example, a common MKP Capacitor is a substitute for a metallized Polypropylene Film Capacitor (metallized Polypropylene Capacitor), and MKT is a substitute for a metallized polyethylene Capacitor (metallized Polyester Capacitor).

The film used for the metallized film capacitor includes polyethylene, polypropylene, polycarbonate, and the like, and there are laminated type as well as the wound type. The capacitor with the metallized film has a so-called self-healing Action (self-healing Action), that is, if a short circuit is caused by a weak electrical interface in a tiny part of the electrode, the electrode metal around the short circuit part will be melted and evaporated in a larger area to recover the insulation due to the electrostatic energy or short circuit current carried by the capacitor at that time, so that the capacitor can recover the function of the capacitor again

In the industry, the explosion-proof block of the existing alternating current metallized film capacitor is generally of a circular structure, the capacitor is poor in sealing due to the fact that the capacitor cover is not tightly attached to the shell, the sealing performance of the capacitor is poor, and when the capacitor is inverted or the temperature inside the capacitor rises, filling materials in the capacitor overflow from the sealing part, so that the performance and the stability of the metallized film capacitor are affected.

Disclosure of Invention

The invention provides a film capacitor, which aims to reduce poor sealing of the film capacitor and improve the capacitance sealing performance of the film capacitor.

In order to achieve the above object, the thin film capacitor of the present invention has the following technical solutions:

a thin film capacitor cover comprising: be provided with a plurality of stoppers on the side edge of condenser lid, the central line of the figure that the outward flange of a plurality of stoppers formed coincides with the central axis of condenser lid, and a plurality of stoppers all contact with the condenser shell inner wall to ensure the central axis of condenser lid and the coincidence of condenser shell's central axis.

Further, the capacitor cover has an explosion-proof block, and a plurality of stopper portions are provided on the side edges of the explosion-proof block.

Furthermore, the number of the limiting blocks is at least 3.

Further, the plurality of limiting blocks are even and are symmetrically arranged on the side edge of the explosion-proof block relative to the central axis of the capacitor cover.

Further, the size of the limiting block covers the whole thickness of the explosion-proof block.

Furthermore, the limiting block is provided with a curved surface contact surface and an inclined installation surface, the curved surface contact surface comprises an arc surface and a plane, the thickness of the inclined installation surface is smaller than that of the curved surface contact surface, and the curved surface contact surface is in contact with the inner wall of the capacitor shell.

Furthermore, the limiting block and the explosion-proof block are made of the same material.

Further, the capacitor cover is circular or square.

According to another aspect of the present invention, a film capacitor is disclosed, which comprises the above capacitor cover.

Furthermore, the capacitor cover comprises an explosion-proof block, a connecting cover plate and a copper foil, wherein the explosion-proof block, the connecting cover plate and the copper foil are of an integrally formed structure.

According to still another aspect of the present invention, a method of manufacturing a thin film capacitor is disclosed, comprising the steps of: a plurality of limiting blocks are arranged on the side edge of the explosion-proof block of the capacitor cover, and the central line of a graph formed by the outer edges of the limiting blocks is superposed with the central axis of the capacitor cover; installing a capacitor cover provided with a plurality of limiting blocks on a capacitor shell which is filled with fillers to perform pressing operation; and sealing the capacitor which is pressed down by using a sealing machine.

According to the film capacitor, the explosion-proof blocks are arranged on the periphery of the capacitor cover, so that the fixing structure or structural rigidity of the capacitor cover is improved, the explosion-proof blocks on the periphery of the capacitor cover are tightly attached to the capacitor shell, the capacitor cover is further tightly attached to the capacitor shell, and finally the manufactured film capacitor has better capacitor sealing quality.

Drawings

The invention will be described in more detail hereinafter on the basis of embodiments and with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of a capacitor cover and a capacitor housing without a limiting structure;

FIG. 2 is a schematic structural diagram of a capacitor cover without a limiting structure;

FIG. 3 is a schematic diagram of a capacitor cover and capacitor housing with added retention features;

FIG. 4 is a cross-sectional view of a capacitor cover provided with an explosion proof mass according to the present invention;

FIG. 5 is a top view of a capacitor cover of the present invention with an explosion proof block;

fig. 6 is a schematic structural diagram of the capacitor cover and the capacitor case after sealing.

Detailed Description

The invention will be further explained with reference to the drawings.

As shown in fig. 1-2, when the explosion-proof block 21 of the capacitor cover 20 of the metallized film capacitor is not provided with a limiting block, and the capacitor cover is covered on the capacitor housing 10, the capacitor cover 20 is not tightly matched with the capacitor housing 10 and has low structural strength, after the capacitor is assembled and filled with the filling material, and the capacitor cover 20 and the capacitor housing 10 are displaced from each other due to the loose matching and insufficient structural strength when the tooling presses down the capacitor cover 20, so that the center line of the capacitor cover is not aligned with the center line of the capacitor housing, and finally the sealing performance of the capacitor cover and the capacitor housing is insufficient.

As shown in fig. 3-5, when the capacitor cover 40 of the metallized film capacitor is provided with the stopper 42, when the capacitor cover 40 is covered on the capacitor housing 30, the capacitor cover 40 and the capacitor housing 30 are tightly fitted and have high structural strength, and after the capacitor assembly is filled with the filling material, when the capacitor cover 40 is pressed down by the tool, the capacitor cover 40 and the capacitor housing 30 are tightly fitted and have sufficient structural strength, so that the capacitor cover 40 and the capacitor housing 30 are not displaced from each other, the center line of the capacitor cover 40 and the center line of the capacitor housing 30 are aligned, and finally, the sealing performance of the capacitor cover 40 and the capacitor housing 30 is improved.

As shown in fig. 3 to 5, the capacitor cover 40 includes an explosion-proof block 41, a connection cover plate 45 and a copper foil 44, and the explosion-proof block 41, the connection cover plate 45 and the copper foil 44 are of an integrally formed structure. The capacitor cover 40 may be circular, square, or other shape. A plurality of stoppers 42 are provided on the side edge of the capacitor cover 40, the plurality of stoppers 42 is at least 3 (in the embodiment shown in fig. 5, the number of stoppers 42 is 4), and when the plurality of stoppers 42 is even, it is preferable that the stoppers are symmetrically provided on the side edge of the explosion-proof block 41 with respect to the central axis of the capacitor cover (the odd number may also be centrosymmetrically). When the capacitor cover 40 is mounted on the capacitor housing 30, the limiting block 42 arranged on the explosion-proof block 41 is tightly attached to the capacitor housing 30, so that the joint tightness between the explosion-proof block 41 and the capacitor housing 30 is increased, the explosion-proof block 41 is tightly attached to the capacitor housing 30, the capacitor cover 40 is further tightly attached to the capacitor housing 30, the center line of the capacitor cover 40 is aligned with the center line of the capacitor housing 30 in the sealing process, and the sealing performance between the capacitor cover 40 and the capacitor housing 30 is improved.

Preferably, as shown in fig. 3, the size of the stopper 42 covers the entire thickness of the explosion-proof block 41, so as to increase the contact area between the stopper 42 and the capacitor case 30, and improve the sealing property and the bonding strength at the sealing position. The limiting block 42 has a curved contact surface (the curved contact surface includes an arc surface or a plane) and an inclined mounting surface, and the inclined direction of the inclined mounting surface is: the outer wall of the capacitor inclines towards the center of the capacitor. The thickness of slope installation face is less than the thickness of curved surface contact surface, and the curved surface contact surface of stopper 42 contacts with capacitor case 30's inner wall, forms laminating portion 43, and stopper 42 slope installation face makes things convenient for stopper 42 to pack into in capacitor case 30. The capacitor cover now contacts the top of the capacitor housing forming a seal 50. The stopper 42 is preferably made of the same material as the explosion-proof block 41 or other materials.

As shown in fig. 3 to 5, when the tooling presses down the capacitor cover 40 after the filling material is poured into the capacitor assembly, the capacitor cover 40 is tightly attached to the capacitor housing 30, and the capacitor cover 40 and the capacitor housing 30 keep the central axis alignment without relative displacement. The capacitor semi-finished product in which the capacitor cover 40 is aligned with the capacitor case 30 can be provided while the capacitor is transferred to the next process (sealing process).

When the capacitor is conveyed to the sealing process, after the clamp clamps the capacitor and places the capacitor to the sealing station, under the action of the sealing machine, the capacitor cover 40 and the capacitor shell 30 are curled to form a sealing part, so that the sealing of the capacitor is realized. In the process, the limit block 42 improves the close fitting degree of the capacitor cover 40 and the capacitor shell 30, so that the capacitor cover 40 and the capacitor shell 30 are ensured not to be relatively displaced or separated, the central axes of the capacitor cover 40 and the capacitor shell 30 are always on the same vertical line, and the capacitor cover 40 and the capacitor shell 30 are not dislocated.

The invention also provides a manufacturing method of the metallized film capacitor, which comprises the following steps: a plurality of stopper blocks 42 symmetrically distributed are formed on the side edge of the explosion-proof block 41 of the capacitor cover 40; installing the capacitor cover 40 provided with a plurality of stopper blocks 42 symmetrically distributed on the side edge of the explosion-proof block 41 on the capacitor housing 30 which is filled with the filler to perform a pressing-down operation; and sealing the capacitor which is pressed down by using a sealing machine.

From this, after condenser lid 40 pushes down to the whole in-process that the condenser sealed the end, because a plurality of stopper 42 that the symmetry set up on the explosion-proof piece 41, make explosion-proof piece 41 and capacitor case 30 closely laminate, make condenser lid 40 and capacitor case 30 not take place horizontal dislocation, guarantee that the center pin of condenser lid 40 and capacitor case 30 is on same straight line all the time, and then guarantee that the condenser seals the size and has better uniformity, it has more excellent leakproofness to guarantee the condenser, improve the electric capacity leakproofness, prevent because condenser lid 40 and capacitor case 30 misplace, the separation is mutual central axis not on same straight line, lead to the bad phenomenon of condenser sealing.

As shown in fig. 6, the structure of the capacitor cover 40 and the capacitor case 30 after sealing is schematically illustrated, and a sealing portion 60 is formed at a contact portion between the capacitor cover and the capacitor case 30 after sealing.

While the invention has been described with reference to a preferred embodiment, various modifications may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In particular, the technical features mentioned in the embodiments can be combined in any way as long as there is no structural conflict. It is intended that the invention not be limited to the particular embodiments disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.