JPS587103Y2 - ignition distributor - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an ignition power distribution device mounted on an engine, and more particularly to an improved structure for ventilation within the power distribution device.

This type of ignition power distribution device, which has been well known in the past, has a cylindrical ventilation tower with a ventilation passage as a ventilation port protruding from a synthetic resin power distribution cap, and a rubber ventilation plug is press-fitted into the cylindrical ventilation tower. I was wearing it.

However, as mentioned above, in a structure in which a rubber ventilation plug is fitted into a cylindrical ventilation tower, the ventilation plug sometimes loosens or sometimes falls off from the ventilation tower due to large vibrations of the engine and deterioration of the rubber.

In particular, ventilation towers have straight ventilation passages, so if the ventilation plug falls off, dust, water droplets, etc. can easily enter the distributor from outside, leading to an engine stoppage in the worst case scenario. There were drawbacks.

In order to solve the above-mentioned drawbacks, this invention makes the ventilation plug made of synthetic resin and welds this ventilation plug to the power distribution cap, so that the ventilation plug will not fall off from the power distribution cap even under harsh usage conditions. In this way, it is an object of the present invention to provide an ignition power distribution device that exhibits stable ventilation performance over time.

Another purpose of the present invention is to provide flexibility in the design of the ventilation passage structure from the inside of the power distribution device to the outside air, thereby further improving ventilation performance.

Embodiments of the present invention shown in the drawings will be described below.

In FIGS. 1 and 2, reference numeral 1 denotes a synthetic resin power distribution cap that is attached to a power distribution device housing (not shown), and has a cap-like body with an inverted U-shape in vertical section as a whole, and usually has 4 cylinders. In this case, a center electrode 2 is provided at the center top, and four side electrodes 3 are provided at equal intervals on the same cylinder surrounding the center electrode.

Furthermore, the power distribution cap 1 is provided with a cylindrical ventilation tower 4 having a ventilation passage 4a located between appropriate side electrodes 3.
is integrally protruded, and the ventilation tower 4 is covered with a plastic ventilation plug 5.

Moreover, the bottom surface of the ventilation plug 5 is welded to the upper surface of the cap 1 near the base of the ventilation tower 4.

The assembly structure of the above-described power distribution cap 1 and ventilation plug 5 will be further explained in a supplementary manner.

In the power distribution cap 1, an annular recess 7 surrounded by the ventilation tower 4 and the annular protrusion 6 is provided around the base of the ventilation tower 4, and an annular groove 7a is further provided within the recess 7.

On the other hand, the ventilation plug 5 has a cap-like body having an inverted U-shape in vertical section with a brim 5a around the open end, and has a depth that is sufficiently larger than the protruding length of the ventilation tower 4.

Moreover, the bag-like portion 5b has a deformed cylindrical shape that is approximately water droplet-shaped, so that only a part of the inner circumferential surface contacts the outer circumferential surface of the ventilation tower 4, and the inner wall surface of the bag-like portion 5b contacts the outer circumferential surface of the ventilation tower 4. A space 8 is provided between the ventilation tower 4 and the passage 4a to form an inverted U-shaped passage.

Furthermore, an opening 5c for opening the space 8 to the atmosphere is provided at the lower end of the bag-shaped portion 5b.

On the other hand, the lower surface of the brim 5a (i.e., the bottom surface of the ventilation plug 5)
includes an annular protrusion 9 that fits into the annular recess 7 of the power distribution cap 1.
The convex portion 9 is further provided with an annular protrusion 9a having a triangular cross section that fits into the annular groove 7a of the power distribution cap 1.

However, the annular convex portion 9 and the annular protrusion 9a are missing at the opening 5c and are substantially C-shaped.

After the power distribution cap 1 and the ventilation plug 5 are combined as shown in FIG.
By applying a high-frequency current under pressure between them, heat generation and melting start from the contact area between the annular groove 7a and the annular protrusion 9a, and the entire bottom surface of the ventilation plug 5 is uniformly coated with the upper surface of the annular protrusion 6 of the power distribution cap 1 and the annular recess. 7 Weld to the bottom.

In this way, the ventilation plug 5 can be firmly and integrally joined to the power distribution cap 1.

According to experiments, good results were obtained when both the power distribution cap 1 and the ventilation plug 5 were made of polypropylene resin, but it was found that good welding was possible not only with the same type of resin material but also with a combination of different types of resin materials. Of course, various resin materials can be selected.

Welding the ventilation plug 5 to the power distribution cap 1 as described above not only increases the mounting strength of the ventilation plug 5, but also
It is notable for its ability to improve the original ventilation function.

That is, the ventilation plug 5 is made of rubber as in the past, and the ventilation tower 4
In the case of the press-fitting method, the shape of the bag-shaped portion 5b of the ventilation plug 5 is made into a cylindrical shape in order to make the crimping area between the ventilation plug 5 and the ventilation tower 4 as large as possible (in terms of installation strength). However, according to the present invention, the ventilation tower 4 and the ventilation plug 5
It is not necessary to make contact with the
As is clear from the figure, by making the bag-like portion 5b into a water drop shape, a space 8 having a dog-like volume and a flexible shape can be formed between the outer periphery of the ventilation tower 4 and the inner wall surface of the ventilation plug 5.

As a result, this space 8 cooperates with the ventilation passage 4a of the ventilation tower 4 to improve the discharge of harmful gases such as ozone generated in the power distribution cap 1, and also to prevent harmful gases such as ozone from entering from the outside through the opening 5c. It is possible to prevent impurities such as dust and moisture as much as possible.

Note that the outer peripheral surface of the ventilation tower 4 and the bag-shaped portion 5b of the ventilation plug 5
If unevenness extending in the axial direction is formed on the inner peripheral surface of the
The cross-sectional shape of the space 8 becomes more complicated, and the intrusion of the impurities can be further prevented.

As described above, in the present invention, a synthetic resin ventilation plug 5 is provided at the lower end of the brim 5a around the open end of the ventilation hole (periphery of the ventilation tower 4) formed in the synthetic resin power distribution cap 1. Since welding is performed by the annular convex portion 9a, the brim 5a
The electrode 10 for welding can be easily arranged, and the annular protrusion 9a protruding from the lower end of the collar 5a can be welded to the cap recess 7a, thereby making it possible to firmly connect the welding electrode 10 as one piece.
Even under severe usage conditions, the ventilation plug 5 does not fall off the power distribution cap 1, and there is an effect that stable ventilation performance can be obtained over time.

In addition, since the bag-like portion 5b of the ventilation plug 5 has a deformed cylindrical shape that is approximately a droplet shape, and only a part of its inner peripheral surface is in contact with the outer peripheral surface of the ventilation tower 4, the ventilation plug 5 and the ventilation tower 4 are Because it is possible to create a space of any shape with a large volume between the two,
This has the great effect of not only improving the discharge of harmful gases within the power distribution cap 1, but also being able to better prevent impurities from entering from the outside.

[Brief explanation of the drawing]

Figure 1 is a top view of the power distribution cap showing an embodiment of the ignition power distributor according to the present invention, and Figure 2 is a cross-sectional view taken along line A-A shown in Figure 1, showing the assembly before welding of the ventilation plug. Indicates the condition. 1...Synthetic resin power distribution cap, 4...
・Ventilation tower, 4a...Ventilation passage, 5...
-Synthetic resin ventilation plug.

Claims (1)

[Scope of utility model registration request] A ventilation tower having a ventilation passage is integrally formed, a synthetic resin power distribution cap having a recess formed around the base of the ventilation tower, a flange around the open end side, and a depth greater than the protruding length of the ventilation tower. a synthetic resin ventilation plug made of a cap-like body having a bag-like part with an inverted U-shaped longitudinal section; Only a part of the surface is in contact with the outer circumferential surface of the ventilation tower, and a space is formed between the ventilation tower and the inner wall surface of the bag-shaped portion to form an inverted U-shaped passage in combination with the ventilation passage. an opening for opening the space to the atmosphere is provided at the lower end of the bag-shaped portion, and an annular protrusion that fits into the recess of the cap protrudes from the lower end of the brim, and the protrusion The ignition distributor has a portion missing at the opening, and further has an annular convex portion of the ventilation plug welded to a concave portion of the cap.