JPS6233409A - Ignition coil for internal combustion engine - Google Patents

Abstract

PURPOSE:To effectively reduce the amount of casting resin used as well as to contrive accomplishment of lightweightedness and low cost by a method wherein casting resin, which is poured and hardened in a case wherein the connected part of a high voltage terminal and a primary coil and a secondary coil are sealed and having an inclined liquid level becoming higher on the side of a high voltage terminal and becoming lower gradually toward the side of the other end, is provided. CONSTITUTION:The liquid level 5a of the casting resin 5 poured and hardened in a case 1 is inclined along the edge of the aperture of the case 1, and a primary coil 2, a secondary coil 3, a connected part 4a, and the high voltage tower 4 located on the side of the connected part 4a are sealed using said casting resin 5. The aperture end of the case 1 used as the container of the casting resin 5 is extended so that the connected part 4a can be sufficiently covered by the casting resin 5 on the side where the high pressure tower 4 is attached, and pertaining to the opposite side (side of core 6), it has an inclined surface which is becoming lower gradually in order to reduce the excessive space as much as possible. When resin is going to be cast, the case 1 is incliningly set so that its aperture end is turned to a horizontal state, and the casting resin 5 is poured in the mold.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an ignition coil for an internal combustion engine.

[Conventional technology]

In the conventional case, as shown in Fig. 7, the primary and secondary coils 2 and 3 are housed in a case 1 having an open end at one end, and the secondary coil 3 is connected to the inner side of the open end of the case 1. The connecting portion 4a of the high-pressure tower 4 is placed, and by injecting a casting resin 5 into the case l from the first end of the case and hardening it, the connecting portion 4a of the high-pressure tower 4 is formed by the casting resin 5.

The primary and secondary coils 2 and 3 are enclosed (for example, Nippon Denso Public Technical Department, serial number 34-147゜3, 1984).
(Published on the 15th of the month).

[Problem that the invention seeks to solve]

However, in the conventional device described above, the opening end of the case 1 is horizontal to the bottom of the case 1, and when pouring resin into the case 1, the bottom of the case must be in contact with a horizontal jig. By doing so, the opening end of the case 1 is kept horizontal and the liquid level of the casting resin 5 is formed along this opening end to harden the casting resin 5.
There is a problem that the amount of casting resin 5 on the inner side of the opening end of the case 1 on the opposite side becomes larger than necessary, making it heavy and expensive.

Therefore, the present invention aims to reduce weight and cost by effectively reducing the amount of casting resin used.

[Means for solving problems]

Therefore, the present invention provides a case having an open end at one end, primary and secondary coils housed in the case, cores forming magnetic paths of the primary and secondary coils, and an open end of the case. A high-voltage terminal having a connecting portion with the secondary coil disposed on the inner side thereof, and a high-voltage terminal that is injected and hardened into the case to encapsulate the connecting portion of the high-voltage terminal and the primary and secondary coils; The present invention provides an ignition coil for an internal combustion engine, which includes a cast resin having an inclined liquid level that is high on the terminal side and gradually lowered toward the other end.

[For production]

As a result, the amount of casting resin on the inner side of the opening end of the case opposite to the high-voltage terminal is reduced by the amount that the liquid level of the casting resin is inclined.

〔Example〕

The present invention will be described below with reference to embodiments shown in the drawings.

In the first embodiment shown in FIGS. 1 to 3, 1 is a cup-shaped case made of synthetic resin, and one end thereof has an inclined opening end, and the higher side of this opening end has an opening facing toward the outer periphery. A bulging portion 1a that swells is formed.

2.3 is the primary and secondary coils housed in the case, 4 is a high voltage tower forming a high voltage terminal, and has a connecting part 4a to be connected to the secondary coil 3, and this connecting part 4a and the high voltage The end of the tower 4 on the side of the connecting portion 4a is disposed within the bulge la on the inner side of the open end of the case 1. 5 is a casting resin that is injected and hardened into the case 1, and its liquid level 5a is the same as that of the case 1.
It is inclined along the opening end, and the primary and secondary coils 2 and 3, the connecting portion 4a, and the end of the high voltage tower 4 on the side of the connecting portion 4a are sealed with this casting resin 5.

6 is a closed magnetic circuit core that forms the magnetic path of the primary and secondary coils 2 and 3, and is constructed by combining two core-shaped core parts in a square shape, one leg of which is connected to the primary coil. It is arranged at the center of the coil 2, and the other leg is arranged along the outside of the side wall of the short casing of the length opposite to the bulging part 1a of the case 1, and one leg is the primary one.

It is enclosed in casting resin 5 together with the secondary coil 2.3. Reference numeral 7 denotes a primary terminal connected to the primary coil 2, which is arranged and fixed inside the open end side of the case 1.

In the above configuration, as shown in FIG. 1, the open end of the case 1, which serves as a container for casting the casting resin 5, is fully connected to the connecting portion 4a on the side where the high-pressure hoe 4 is attached.
The opposite side (core 6 side) has a slope that gradually becomes lower in order to reduce excess space as much as possible, and when resin casting, case 1 is made so that the opening end is horizontal. It is set at an angle and the casting resin 5 is cast.

Here, the resin 5 to be cast is subject to a drop in the liquid level during curing and variations during manufacturing, and if a high-pressure part were to be exposed, reliability would be extremely impaired. For this reason, when resin is poured into a case with a flat open end as shown in FIG. Casting is required, and the length of the leg of the core 6 is also required to be longer by the height of the extra resin 5 injected, but this example does not solve this problem. There is no. In addition, in this embodiment, if the high-voltage tower 4 is installed so as to face upward as shown in FIG. It never gets boring and your trustworthiness improves.

In addition, as in the second embodiment shown in FIGS. 4 and 5, E
In the case of the mold core as well, the amount of casting resin can be reduced by making the opening of the case 1 a sloped surface. In this case, the length of the legs of the core 6 can be shortened only slightly, so if you only want to reduce the amount of casting resin, as in the third embodiment shown in FIG. It is possible to tilt only the liquid level 5a of the casting resin by setting the casting resin obliquely at a predetermined angle and casting.

In the above-described embodiment, one leg of the core 6 was sealed in the casting resin, but after the casting resin was injected into the hollow case and hardened, the core was fitted and fixed in the hollow part of the case. Alternatively, a part of the core may be integrally molded into the case in advance, and the core is not limited to a closed magnetic circuit core, but may be a single-shaped open magnetic circuit core.

〔Effect of the invention〕

As described above, in the present invention, since the casting resin liquid level is tilted, the amount of casting resin on the inner side of the case opening end opposite to the high voltage terminal is reduced, so the insulation of the high voltage terminal part is improved. It has the excellent effect of being able to reduce the overall weight and cost without any loss.

[Brief explanation of drawings]

1 to 3 are longitudinal cross-sectional views, plan views, and back views showing a first embodiment of the coil of the present invention, and FIGS. 4 and 5 are front views and side views showing a second embodiment of the coil of the present invention. Figure, 6th
The figure is a front view showing a third embodiment of the coil of the present invention. 1...Case, 2...Primary coil, 3...Secondary coil. 4... High voltage tower forming a high voltage terminal, 4a... Connection part. 5... Casting resin, 5a... Liquid level, 6... Core. Representative Patent Attorney Takashi Okabe Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Procedural amendment November g, 1985 Patent Application No. 173843 2 Invention Name: Ignition Coil for Internal Combustion Engine 3 Relationship with the Case of Person Who Amends Patent Applicant: Ai Absence 1. %lJ 1-1 Showa-cho, Tani-shi (426) Nippondenso Co., Ltd. Representative Kengo Toda 4th 1-5 Showa-cho 448 1-5 Showa-cho, Kariya-shi, Aichi Prefecture Date of amendment Old dispatch date October 29, 1985 Day 7 Roku Koyama in Kei (11 Specification, page 8, line 7, "Front view" and "is".
Insert ``Figure 7 is a vertical cross-sectional view of a conventional coil'' between.

Claims (2)

[Claims] (1) A case having an open end at one end, primary and secondary coils housed within the case, a core forming a magnetic path for the primary and secondary coils, and an inner side of the open end of the case. a high voltage terminal in which a connection part with the secondary coil is arranged;
A cast mold is injected and hardened into the case to enclose the connecting portion of the high voltage terminal and the primary and secondary coils, and has an inclined liquid level that is high on the high voltage terminal side and gradually lowers toward the other end. An ignition coil for an internal combustion engine comprising a resin. (2) The ignition coil for an internal combustion engine according to claim 1, wherein the opening end of the case is also inclined along the liquid level of the casting resin.