JPS6216541B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a method of covering an electrical device (component) that is housed in an outer shell and that includes at least one row of electrical terminals that protrude outside the outer shell. , the coating is a hermetic coating formed by immersing the electrical device in a liquid coating material.

For mechanical protection purposes, electrical devices are often housed in an envelope from which at least one row of electrical terminals of the electrical device protrudes.
These include in particular electrical and mechanical devices, such as relays. Most such electrical devices are soldered directly into holes in printed circuit boards, which are at least partially immersed in a soldering bath and a cleaning bath, as well as the printed conductor substrate itself. It has individual electrical equipment. In such operations, there is a risk that liquid or gaseous substances may enter the interior of the envelope through holes or gaps, which could damage the electrical equipment housed therein. For example, in the case of an electric relay, there is a risk that its contacts may be contaminated by substances that have entered the relay. Contaminants may enter the housing of the electrical terminal through gaps between individual parts in a housing housing a plurality of parts, or through the point where the electrical terminal is pulled out from the bottom of the housing. Due to the difference in thermal expansion coefficient between the outer cover material and the electrical terminal material, the drawer part from the bottom of the body is
Microscopic gaps are often present.

Attempts have been made to make such electrical devices wash-resistant by various means.

For example, using ultrasound or a heated wand,
Attempts have been made to close non-hermetic points by thermoplastically deforming portions of the envelope. Attempts have also been made to house the envelope in plastic material. However, these conventional methods suffer from considerable consumption of working time and materials used.

It is also known to provide a thermoplastic body made of insulating material in the form of either a foil or a container with recesses that fit snugly into the pins of the electrical terminal (German Patent Publication No. 2129918). reference). However, the foil placed there deforms due to temperature effects and does not provide a sufficient seal.

Finally, an absorbable coating layer is already placed on the electrical terminal, which is known to be impregnated with a thin liquid sealing compound (German Patent Application no.
(See No. 2616299).

However, this conventional method not only requires the use of secondary materials to be separated from the sealing compound, but also the coating layer must be precisely cut to the dimensions of the electrical device. and must be of the same size as the electrical equipment.

In practice, the wash-proof sealing of the housing of the electrical element can be obtained in a simple manner, such as by coating the housing with a thin film of a sealing compound, such as lacquer.
In the simplest way, such a coating is obtained by dipping the envelope in a liquid coating material.
However, this practically simple and effective method has the disadvantage that the coating material also adheres to the terminals of the electrical device and that the deposited coating material has to be removed from the terminals again. Removal of the coating material from the electrical terminal is very expensive since simple dipping methods have not yet reached the point of practical use.

The object of the invention is to provide a coating method of the above-mentioned type, in which it is possible to prevent the electrical terminals from being contaminated by the coating material in a simple manner.

The above object of the present invention is to provide at least one row of electrical terminals housed in an envelope and projecting to the outside of the envelope, the electrical terminals being coated by being immersed in a liquid coating material. A method of coating an electrical device subjected to a hermetic treatment, the following steps being carried out prior to said dipping treatment: each adhesive being applied to the tape and to the opposite sides of the other tape opposite said tape; inserting and arranging the electrical terminal between two facingly disposed covering means having a layer, and pressing the two covering means with a cooperating roller to press the two covering means together; The present invention is achieved by a method of covering an electrical terminal in an electrical device, comprising the step of hermetically covering the electrical terminal in between.

It is particularly advantageous to surround the electrical terminals arranged in a row on both sides by two oppositely arranged adhesive tapes.

In order to obtain a good seal around the electrical terminal, the electrical terminal can be designed either as a circular metal pin or wire, but also with a square or rectangular cross-section, and the adhesive tape should be flexible. is suitably crimped against the electrical terminal by a roller made of a material having a In this way, it is ensured that no gaps remain between the adhesive tape and the electrical terminal and that no coating material can pass through.

In order to ensure that in any case the electrical terminal is completely surrounded by the adhesive tape, it is possible to choose the adhesive layer to have a thickness corresponding to at least half the diameter of the electrical terminal. It's advantageous. In this regard, the adhesive tape does not need to be completely crimped around the electrical terminal, since the electrical terminal is itself embedded within the thick adhesive layer.

It is desirable to use an adhesive tape having a width greater than the length of the electrical terminal of the electrical device, so that the adhesive tape completely surrounds the free end of the electrical terminal.

In the case of electrical devices in which the electrical terminals are partially exposed by a lateral recess in the bottom surface of the envelope, the adhesive tape can be placed in such a way that it approaches the bottom surface of the envelope. This ensures that the electrical terminal is reliably coated on the bottom (supporting surface) of the envelope. The electrical terminal opening is reliably sealed in a wash-resistant manner by means of a lacquer that penetrates into the recess of the envelope.

The invention will be explained in more detail with reference to the accompanying drawings, FIGS. 1-6.

In order to tightly seal the electrical terminals of the electrical device, two adhesive tapes 6 and 9 are preferably used, as shown in FIG. band body 7 or 10,
and an adhesive layer 8 or 11. The base strip may be constructed of paper or plastic material.
The electrical device, for example an electric relay, has an outer shell composed of two halves 2 and 3, and the outer shell has two parallel rows of electrical terminals 5 protruding from the bottom surface thereof. ing. The adhesive tapes 6 and 9 are prestripped by corresponding supply reels (not shown) and, if necessary, guided by suitable pulleys (not shown). The two adhesive tapes 6 and 9 are then introduced between the two rollers 12 and 13, which rollers are made of an elastic material,
For example, it is made of rubber. Furthermore, the shafts 14 and 15 of the two rollers can be supported resiliently by pressing the rollers together.
A row of electrical terminals 5 is introduced between the two adhesive tapes 6 and 9 in the case of FIG. 1 from left to right in the figure. By adopting a suitable driving method, the two rollers 12 and 13 rotate in the direction indicated by the arrow, and the adhesive tape 6
and 9 are crimped together and the adhesive tape is affixed around the electrical terminal 5. At the same time, also in the case of FIG. 1, the electrical device is transported further from left to right. The two adhesive layers 8 and 11 are bonded to rollers 12 and 13 by enclosing the electrical terminals between double tapes 17.
are glued together on the right-hand side.

Similarly, the other row of electrical terminals 5, namely the lower row in the case of FIG. 1, is also enclosed between two adhesive tapes. By dipping, the electrical device is provided with a suitable coating with the lacquer, after which the two adhesive tapes are removed from the electrical terminal by being pulled apart. In this simple method, the electrical device housed in the envelope can be sealed in a completely wash-tight manner without any particular increase in its dimensions. In this way, a sealing compound enters the gap existing between the two halves 2 and 3 of the envelope and may furthermore be formed at a point between the electrical terminal 5 and the envelope. Get into the gap. The viscosity of the dipping lacquer can be easily adjusted to a viscosity that reliably prevents the lacquer from penetrating into the interior of the envelope.

FIG. 2 is a side view of the electrical device with coated electrical terminals. The two-part envelope is covered on top by a cover 4, one half 2 of which is shown in FIG. Also, the gap between the two halves of the envelope and the cover must be sealed. The electrical terminal 5
is completely inserted between the double tapes 17, i.e. the free end of the electrical terminal 5 is inserted between the double tapes 17
completely buried inside. This is accomplished in that the adhesive tape has a width that is greater than the length of the electrical terminal 5.

Of course, it is not only possible to carry out the coating method described above for individual electrical devices, but also to embed the electrical terminals of a number of electrical devices in succession between the adhesive tapes. Thus, not only is the embedding of the terminals of a large number of electrical devices carried out in succession, but also the immersion into the sealing compound and the removal of the adhesive tape after application of the compound is carried out in a continuous process.

FIG. 3 is a side view showing a plurality of electrical elements 1 with electrical terminals 5 surrounded by double tape 17.

FIG. 4 is a bottom view of the same arrangement as shown in FIG.
and 18.

FIG. 5 shows a side view of the electrical component, the housing of which is provided with a lateral recess 19 at the point where the electrical terminal 5 leads out.

FIG. 6 is a cross-sectional view of the electrical device taken along line AB in FIG. 5. In the case of such electrical equipment,
The electrical terminal 5 is completely covered up to the bottom surface (supporting surface) of the envelope because the sealing compound prevents the electrical terminal from leading out of the envelope due to the presence of the recess 19. This is because a tight seal is still maintained at this point. The bottom surface of the electrical device around the electrical terminals 5 is free of lacquer protrusions, which cause difficulties even when the electrical terminals are to be soldered into very thin printed circuit boards. There's nothing to do.

As described above, according to the present invention, a coating capable of preventing contamination of electrical terminals can be obtained by a simple method.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram illustrating the application of a covering adhesive tape to an electrical terminal according to an embodiment of the present invention;
FIG. 3 is a side view of the structure of FIG. 2, and FIG. 4 is a bottom view of the electrical device with covered electrical terminals according to the present invention. , FIG. 5 is a side view of an electrical device having transverse recesses for terminals in the housing according to a modified embodiment of the invention, and FIG. 6 is a sectional view taken along the line AB of FIG. 5. (Explanation of symbols) 1...Electrical device, 2, 3...2 divided body, 4...Cover, 5...Electric terminal, 6, 9...Adhesive tape, 7, 10...Base band, 8, 11...Adhesive layer, 12, 13...roller, 14,15...shaft body,
17, 18...double tape, 19... recessed portion.

Claims (1)

[Scope of Claims] 1. A device comprising at least one row of electrical terminals housed in an outer shell and protruding to the outside of the outer shell, and capable of being coated by being immersed in a liquid coating material. A method for covering electrical equipment subjected to hermetic treatment, the method comprising:
The following steps are performed prior to the soaking process:
inserting and arranging said electrical terminal between two opposingly disposed covering means, each having a tape and an adhesive layer adhered to opposite sides of the other tape opposite said tape; A method for covering an electrical terminal in an electrical device, comprising the steps of: pressing the two covering means with cooperating rollers to hermetically cover the electrical terminal between the crimped covering means. 2. A method as claimed in claim 1, in which the cooperating roller is made of an elastic material and the coating means is pressed by the elastic roller. 3. A method according to claim 1 or 2, characterized in that the thickness of the adhesive layer corresponds to at least half the diameter of the electrical terminal. 4. According to any one of claims 1 to 3, wherein the width of the adhesive layer and the tape is larger than the length of the terminal portion of the electric element that protrudes outside the outer cover. Method described. 5. When the electrical terminal is partially exposed in a lateral recess on the bottom surface of the outer cover,
5. The method according to claim 1, wherein the adhesive layer and tape are placed in close contact with the bottom surface of the envelope.