JPS5821111B2 - ignition distributor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ignition power distribution device used in an ignition system of an automobile engine, and more particularly to the configuration of an electric circuit of the ignition power distribution device.

In this type of ignition distributor, a large-capacity capacitor is inserted between the power supply circuit and the ground for the purpose of suppressing sparks that occur between the contacts of the interrupter built into the distributor. As is known, with the opening and closing of the interrupter contacts,
A noise potential in a high frequency range that cannot be absorbed by the capacitor is generated in the power supply circuit, and as a result, noise radio waves are radiated from the ignition power distribution device to the outside. It is also a cause of radio interference.

The present invention has been made in order to suppress the generation of the above-mentioned radio noise, and an object of the present invention is to suppress the generation of radio noise by using a very simple structure when attaching a small-capacity capacitor. An object of the present invention is to provide an ignition power distribution device that reduces the level of radio wave interference.

The present invention will be described below based on the illustrated embodiments. As shown in FIGS. 1 to 3, a board 2 is attached to a step formed on the upper inner circumferential wall of the power distributor housing 1. At the same time, a support plate 4 in the form of a circular disc is loosely fitted and supported on the camshaft 3 that passes through the shaft center hole of the base plate 2, and the support plate 4 is rotated at a slight arc angle with respect to the base plate 2. is movably supported by a base plate 2, and a interrupter 5 is mounted on the base plate 4.

One part of the upper edge of the casing 1 is formed thin and cut into a rectangular shape to form a mounting step 1a for the small capacity capacitor 6. A snap plate 7 holding the capacitor 6 is fitted by insertion.

As shown in FIG. 4, this snap plate 7 is made by folding an elastic conductive plate into a waveform to form a double plate with a front plate 7a and a back plate 7b spaced apart. Plate 7a
, the hem of 7b is rounded in the opening direction, and is it a drawing board?
A step portion 1a is sandwiched between a and 7b, so that the snap plate 7 is fixed to the housing 1 by the self-retaining property of the spring force simply by inserting the snap plate 7.

Therefore, each plate 7a, 7b has circular window holes 7 facing each other.
A grounding flange 6a fixed to the intermediate portion of the capacitor 6 is fixed to the outer peripheral surface of the window hole 7c of the top plate by welding or the like.

This capacitor 6 has a through terminal 6b at its axis,
In addition, the terminal 6b also serves as a power supply terminal that penetrates the peripheral wall of the housing 1, and therefore, the outer end of the terminal 6b is connected to a primary power supply wire for ignition (not shown), and The inner end is electrically connected to a connecting terminal 9 fixed to the support plate 4 via a conductive wire 8.

Thus, the movable contact 10 of the interrupter 5 is electrically connected to the terminal 9 via the leaf spring 11 for biasing the contact piece, and the fixed contact 12 is directly fixed to the rising piece of the support plate 4. ing.

In addition, the outer end of the capacitor terminal 6b is connected via a conductive wire 13 to an ordinary large-capacity capacitor 14 for spark suppression, which is directly attached to the outer wall of the casing 1 and It is grounded to the housing 1 via the mounting portion 14a.

Note that the above-mentioned substrate 2 and support plate 4 are in contact with the housing 1 and are grounded, so that in the circuit system of the embodiment power distributor,
As shown in FIG. 5, the ignition power supply circuit is grounded in parallel through both capacitors 6.14.

By the way, the small capacity capacitor 6 can be attached to the step part 1a of the case by not only using the above-mentioned snap plate 7 but also by providing slits on both sides of the step part 1a for attaching one person to the case, as shown in FIGS. 6 and 7. 1b, a snap plate 7A is formed using a plate spring having a corrugated cross section, and the ground terminal 6a of the capacitor 6 is fixed to the snap plate 7A.
Alternatively, as shown in FIGS. 8 and 9, the snap plate 7B may be formed by folding the leaf spring into a bulge shape, and the snap plate 7B may be inserted into the slit 1b. It may be inserted into 1b.

Next, the electrical operation of this power distributor will be explained with reference to FIG.

In this power distribution device, like the conventional power distribution device, the interrupter contact 1
The primary current is interrupted by switching between 0 and 12, but during its operation, the high frequency voltage generated in the power supply circuit at the time the contact is opened is blocked by the high impedance due to the inductance of the conductor 13, and the large capacitor 14 Therefore, the conductors 8 and 13 in the power supply circuit cannot be absorbed.
Then, noise radio waves are radiated to the outside from an external primary circuit connected thereto.

However, in this embodiment of the power distribution device, a low-pass filter, that is, a high-pass filter, is formed by coupling the inductance components of the conductors 8 and 13 with the capacitor 6, which has almost no inductance and has a small capacity. Therefore, a low impedance shunt is created, which absorbs noise voltage in the high frequency range and effectively suppresses harmful radio noise.

Here, according to the test results of the example power distribution device conducted by the inventor of the present application, as shown in the graph of FIG. Confirmed, especially 200
In the range of MH2 to 400 Mn2, a significant level reduction was confirmed compared to conventional power distributors.

As described above, according to the ignition power distribution device of the present invention, when the ignition current carrying circuit in the power distribution device is grounded via the small capacitance capacitor, thereby forming a low impedance shunt, the above-mentioned capacitor The capacitor can be fixed to the conductive part by the extremely simple process of inserting the snap plate that is the mounting member, and this effectively eliminates the radio noise generated in the primary circuit for ignition via the capacitor. 0, which has the effect of significantly reducing the level of interference radio waves radiated to the outside.

[Brief explanation of drawings]

FIG. 1 is a schematic plan view of an ignition distributor showing an embodiment of the present invention, FIG. 2 is a side sectional view taken along line T in FIG. 1, and FIG. 4 is a perspective view of the snap plate, FIG. 5 is a diagram of the electric circuit of the power distributor shown in FIG. 1, and FIG. 6 is an exploded perspective view of the power distributor section showing another embodiment. FIG. 7 is a side sectional view of FIG. 6, FIG. 8 is a perspective view of a snap plate showing another embodiment, and FIG. 9 is a perspective view corresponding to FIG. FIG. 10, which is a diagram showing how the snap plate shown in FIG. 8 is attached, and which corresponds to FIG. 7, is a characteristic graph of the noise level showing the test results of the power distributor of the example. 1.1 person...Distributor housing, 5...Interrupter, 6...Small capacity capacitor as power supply terminal, 6A. 6B...Small capacity capacitor, 9...Connection terminal, 14...Normal capacitor.

Claims (1)

[Claims] 1. Ground the ignition current carrying circuit between the ignition power supply terminal penetrating the peripheral wall of the power distribution device housing and the connection terminal leading to the interrupter built into the power distribution device via a small capacity capacitor,
In parallel with a normal capacitor for spark suppression, this
In an ignition power distribution device characterized in that a circuit for absorbing high frequency voltage is formed, the small capacity capacitor is inserted into a mounting portion provided in a power distribution device case using a snap plate having a spring force. An ignition distributor featuring: