JPS6111503Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to the shape of a power distribution rotor for engine ignition.

Conventional power distribution rotors for engine ignition have been manufactured by fitting electrodes made of brass or the like into a mold, melting an insulating material such as polypropylene at high temperature and pressure, and then injection molding the melted material into the mold.

As a result, the adhesion between the electrode and the insulating material can be strongly maintained, but in order to fit the electrode into the mold, it must be manually set (the molding machine takes 200 seconds to melt and flow the resin). a temperature of ℃ or higher,
A pressure of 800 kg/cm ³ or more is generally required, and automatic assembly machines that automatically load electrodes into molding machines under this condition require very complicated protection devices and are expensive, so they must be set manually. It is unsuitable for mass production and has the disadvantage of being expensive.In addition, during injection molding, the flow of molten insulating material is disturbed by the cooled electrode, and
The insulating material in contact with the electrode is cooled, making it easier to form a joint with the molten part (called a weld mark), and creating bubbles under the electrode (the insulating material is melted by the air in the mold and the gas generated from the insulating material). When the high voltage of about 30KV is applied to the distribution rotor, these bubbles cause corona discharge, which deteriorates the surrounding insulation material and causes dielectric breakdown.

This idea was made to eliminate the above-mentioned drawbacks of the conventional ones, and the electrodes are fixed to the power distribution rotor by injection molding of an insulating material using heat such as ultrasonic waves.

An embodiment of this invention will be described below with reference to the drawings. In FIG. 1, numeral 1 indicates a power distribution rotor made of thermoplastic resin such as polypropylene, and numerals 2 and 3 indicate protrusions. FIG. 2 is a cross-sectional view taken from FIG. 1, and FIG. 3 shows a detailed view of the protrusions 2 and 3. The protrusion 2 has a guide portion 2'' at its base and a tapered portion 2' at its tip, with the outer diameter of the guide portion 2'' being Y and the tip diameter of the tapered portion 2' being X (X<Y). FIG. 4 shows the electrode 4, which has holes 4a and 4b. this hole 4
The inner diameters of a and 4b are slightly larger than Y. FIG. 5 shows this electrode 4 fixed to the power distribution rotor 1. After injection molding the power distribution rotor 1 and removing it from the mold, holes 4 for electrodes 4 are formed in the protrusions 2 and 3.
Attach the protrusions 2, 4b so that they engage with each other, and
The taper portion 2' of No. 3 is heated by vibration using, for example, an ultrasonic caulking machine, melted, and deformed by pressure.
The crushed portions 5 and 6 are formed to fix the electrode 4 to the power distribution rotor 1. A cross-sectional view of the compressed portions 5 and 6 is shown in FIG. The hole 4b of the electrode 4 engages with the guide portion 2'', and only the tapered portion 2' is crushed.
The corner portion 5' is rounded as shown.

Since the tip of the protrusion 2 (the protrusion 3 is also the same) is tapered, it is easy to attach the electrode 4 to the power distribution rotor 1, and it acts as a guide for the holes 4a and 4b of the electrode 4. Since the diameter is reduced from a slightly smaller position to the taper part, the protrusion 2,
After the melting and deformation in step 3, the corners are not square but rounded, which increases the strength of the protrusion and increases the fixing force of the electrode 4.

In the above embodiment, the material is melted by vibration heating using ultrasonic waves and deformed and fixed by pressure, but it may be applied heat by other methods, melted, and deformed and fixed by pressure. Also, although two protrusions 2 and 3 are provided, it goes without saying that the same effect can be obtained with just one protrusion. Furthermore, although a case has been described in which the power distribution rotor is molded with thermoplastic resin such as polypropylene, thermosetting resin such as epoxy may be press-molded.

As described above, according to this invention, after the power distribution rotor is molded with an insulating material, the electrodes are engaged with the projections provided on the power distribution rotor, and the projections are deformed to fix the electrodes and the power distribution rotor. As a result, the molding of the power distribution rotor can be done unmanned, and the fixing of the electrodes to the power distribution rotor can be done automatically.In addition, since there are no electrodes during molding, the molten resin flows smoothly and cooling occurs stably. Therefore, it has the effect of producing a power distribution rotor that is less likely to produce weld marks or bubbles inside and has excellent electrical insulation properties. Furthermore, since the protrusion is tapered and heated and pressed, the base of the deformation becomes rounded and the crimping strength can be increased.

[Brief explanation of the drawing]

FIG. 1 shows a plan view of an embodiment of the present invention. 2 is a cross-sectional view of FIG. 1, FIG. 3 is a detailed view of the projection 2, FIG. 4 is a plan view of the electrode 4, and FIG. 5 is a cross-section of the electrode 4 and the distribution rotor 1 fixed together. Figure, 6th
The figure shows a detailed view of the crushing part 5. In the figure, 1 is a power distribution rotor, 2 and 3 are projections, 4 is an electrode, 4a and 4b are holes, and 5 and 6 are crushed portions. Note that the same reference numerals in each figure indicate the same parts.

Claims (1)

[Scope of utility model registration request] A power distribution rotor made of an insulating material, at least one protrusion provided on the power distribution rotor, and an electrode made of a metal material having a hole that engages with the protrusion, the protrusion having a diameter smaller than the hole of the electrode. a guide part having a diameter of A power distribution rotor for engine ignition, in which the protrusions are deformed to fix the electrodes and the power distribution rotor.