JPS6325337Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an ignition timing control device for an internal combustion engine using a diaphragm, and particularly relates to an improvement of a device using a plurality of diaphragms.

Ignition timing control devices for internal combustion engines that originally used two diaphragms had diaphragm stoppers on the casing and diaphragm sides to regulate the operation of the first diaphragm, and the stoppers came into contact with each other. , which sets the stroke of the diaphragm.

Conventionally, the stopper provided on the diaphragm side is a metal plate, and the stopper provided on the casing side is also metal, which has the drawback of severe wear at the contact part, and it is already known to use a resin material as the stopper on the casing side. .

Below, we will explain the case in which a resin stopper is provided on the casing side using figures. In Fig. 1,
The first casing 1, the second casing 2, and the cover 3 form the entire casing, and the second casing 2 consists of two parts 2a and 2b, and between the first casing 1 and a part 2a of the second casing 2. 1st
A diaphragm 4 is clamped. The second diaphragm 5 is circumferentially sandwiched between a portion 2b of the second casing 2 and the cover 3. The first casing 1 and the first diaphragm 4 form a first negative pressure chamber A, and the first diaphragm 4, the second casing 2, and the second diaphragm 5 form a second negative pressure chamber B. Backing plates 6 and 7 and a stopper 8 on the diaphragm side are fixed to both sides of the first diaphragm 4 together with a rod 9 of the first diaphragm 4. A backing plate 10 and a stopper 11 on the diaphragm side are fixed to the second negative pressure chamber side of the second diaphragm 5 together with a rod 12 of the second diaphragm 5, and the rod 12 protrudes into the atmosphere. 13 is the operating spring of the first diaphragm 4, 14 is the negative pressure intake port of the first negative pressure chamber A, 15 is the operating spring of the second diaphragm 5, and 16 is the second
This is the negative pressure intake port for negative pressure chamber B. Reference numeral 17 denotes a stopper which is integrally formed with an initial setter 17a for determining the setting position of the first diaphragm 4 and a stopper 17b on the casing side for determining the stroke, and its overall shape is as shown in FIG.

To explain below, a hole 17c is made in the center of a circular flat plate, a circular protrusion 17d is provided on one side, and the hole 1
A groove 17e is cut in the longitudinal direction centering on 7c. This method of attaching the stopper 17 involves press-fitting the circular protrusion 17d of the stopper 17 into the bottom hole 2c of the part 2a of the second casing 2 and fixing it. The longitudinal groove 17e is a groove used to assemble the stopper 8 on the first diaphragm 4 side.

The device assembled as described above controls the ignition timing by introducing negative pressure into the first negative pressure chamber A and the second negative pressure chamber B, and operating the first diaphragm 4 and the second diaphragm 5, respectively. However, there is a problem with the shape of this conventional stopper 17. In other words, as mentioned above, when assembling the stopper 17, conventionally the protrusion 17d is inserted into the bottom hole 2 of the casing.
It is simply press-fitted into c, and it may rotate during operation and come off. The present invention attempts to eliminate the above-mentioned drawbacks, and will be explained using the following figures. In Figs. 2, 4, and 5,
A notch 17f of the same width is provided in the circular protrusion 17d of the stopper 17, and the part 2 of the second casing 2
A burring portion 2d is provided in the bottom hole 2c of a, and the burring portion 2d is engaged with the notch 17f. Other aspects are the same as the conventional product.

The structure of the present invention has been explained above, and its effect is that the stopper 17 engages with the notch 17f and the burring portion 2d of the casing, preventing rotation during operation and preventing the stopper 17 from coming off. As explained above, the present invention can fully eliminate the drawbacks of ignition timing control devices having a structure in which the stopper is molded from a different material such as resin.

[Brief explanation of the drawing]

Figure 1 is a sectional view of the conventional product, Figure 2 is a sectional view of the invented product, Figure 3 is a diagram showing the shape of the conventional stopper, and Figure 4 is a diagram showing the shape of the invented stopper. be. FIG. 5 is a detailed perspective view of the main parts of the second casing 2 in FIG. 2.

Claims (1)

[Scope of utility model registration request] A casing, a diaphragm stretched over the casing to define a negative pressure chamber, and a stopper disposed within the casing to regulate the initial position and maximum stroke of the diaphragm, the diaphragm being introduced into the negative pressure chamber. In the device for controlling the ignition timing of an internal combustion engine according to the negative pressure generated, the stopper has a circular protrusion and a notch formed on the outer periphery of the circular protrusion, and the casing has a groove in which the circular protrusion is fitted. 1. An ignition timing control device for an internal combustion engine, characterized in that the ignition timing control device for an internal combustion engine has a bottom hole and a burring portion that engages with the notch.