JPS5880282A - Noise preventing device for ignition plug connector - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a noise prevention device that improves the noise prevention effect of spark plugs used in internal combustion engines.

Radio noise generated from the ignition system related to tPIm in spark ignition has become a social problem in recent years, and various measures have been taken to reduce it. As a typical example, a spark plug noise prevention device that combines a resistor-containing spark plug and a resistor-containing cord is generally used, but its noise prevention effect is not fully satisfactory.

Therefore, for spark ignition engines that are not equipped with a power distribution device, such as motorcycles, a wire-wound resistor cord is combined with a shield around the spark plug, as already disclosed by the present applicant in Japanese Patent Laid-Open No. 56-66455. It has been found that an extremely excellent noise prevention effect can be obtained by doing so. When applied to an actual two-wheeled vehicle, a synthetic resin type sleeve with good removability is generally used, so a method of firmly connecting the resistance-containing cord and this resin sleeve is required. In addition, in the case of four-wheeled vehicles, there are cases where a resistance-containing cord is used via a resin sleeve in DOHO engines with deep spark plugs, but in such cases, a connector crimped to the cord is used. Since the metal fitting is held inside the sleeve body, the connection part of the spark plug is limited to one with a screwed terminal nut or an integrated terminal, and the so-called screw type male terminal without a terminal nut is used. It was unsuitable for things like this.

Further, by adding waterproof rubber caps to both sides of the resin sleeve, waterproofness can be provided to some extent, but especially for vehicles without bonnets such as two-wheeled vehicles, something with further improved waterproofness is required.

The present invention has been made in view of the above points, and the connection part of the spark plug can be used not only for the terminal nut type of a four-wheeled vehicle, but also for a spark plug with a screw type terminal male thread used for a two-wheeled vehicle. A noise prevention device for a spark plug connector that has the total length of the metal fittings as short as possible, less than 7r4011@, has a connection means that can further demonstrate the noise prevention effect of a wire-wound resistor cord, and has improved waterproofness. The purpose is to provide.

The present invention will be explained below based on embodiments shown in the drawings.

Fig. 1 is a cross section of the spark plug connector of the present invention. In the figure, 1 is a wire-wound resistance cord, for example, a glass fiber surrounding tube is coated with a ferrite magnetic material mixture, and a resistance wire is wound around the outer tube. At the same time, an insulating coating is applied. The synthetic resin sleeve 2 is made of 7-enol resin or the like, and the inner diameter of one half on the plug terminal insertion side is large, and the outer diameter of the other part from the crotch seat 2b is made equal to the outer diameter y of the cord l. 8#i @1 Connector fitting for holding and electrically connecting the wire-wound resistor-containing cord lt-w! As shown in Fig. J2, the crimping part 8aKF is composed of a crimping part 8 having a U-shaped cross section that connects to the cord, and a projection plate abt that comes into contact with a spring to be described later.
i The terminal portions of the cords are joined by stripping the core portion or by crimping via the Fi welding piece 4t in a known manner. Due to the crimping of the $1 connector fitting, the end portion of the cord L cannot be inserted into the other half of the sleeve. The length of this connector fitting 8 is the overall length t-4011
In order to keep it below 1, it is desirable to keep it below 20 MII.

Reference numeral 5 designates a second connector metal fitting that grips the terminal of the spark plug, and as shown in FIG. A stopper spring 6 that grips the male screw or terminal nut shape is secured by providing a groove 5b across the outer periphery of the metal fitting so that it is exposed in a part of the fitting hole, and a threaded portion is provided on the outer periphery of the middle body of the metal fitting. 5
c is provided, and a step portion 5d with a small diameter is provided on the connection side with the first connector metal fitting, and a spring 7 is disposed on the step portion 5d, which is pressed against the protruding plate 8b of the connector metal fitting 8 for electrical connection. Reference numeral 8 denotes a rubber boot disposed on the outer periphery of the resin sleeve, with extensions on both sides in the axial direction of the rubber boot.
8 b is the resistance-containing cord and the insulator head of the spark plug (
(not shown).

Although the fitting hole 51 of the connector fitting 5 has a bottom, it may be a through hole.

Next, the assembly of the spark plug connector of the present invention will be described. The wire-wound resistance cord I K11l, 1 connector metal fitting 8t, which has been crimped and joined in advance, is attached to the free end side fitting 8.
Lock the end face of the After that, the stepped portion 5 of the second connector fitting 5
The spring 7t is fitted into the spring 7t, and the threaded portion 5ct of the second connector fitting is screwed into the screw thread 2c provided in the shaft hole of the resin sleeve 2. At this time, the sedge ring 7 comes into contact with the protrusion plate 8b of the first connector metal fitting 8 to establish an electrical connection, and both connector metal fittings are fixed within the resin sleeve. This resin sleeve is inserted and fixed into the rubber boot 8.

In addition, in order to keep the total length (j) of the connector metal fittings to 40 mm or less in terms of the noise prevention effect of the uninvented spark plug connector, the length of the second connector metal fitting 5 is regulated by the length of the plug terminal. Therefore, it is important to keep the length of the first connector fitting 8 as short as possible to 20 mm or less, and to keep the overall length to 4011 mm or less. And by making the total length less than 401W,
The fins can be effectively used as a noise prevention device for large two-wheeled vehicles that fulfills the role of a shield, and since the radiation medium used as the connector fitting can be shortened, it can work advantageously in terms of noise prevention effects.

As described above, the spark plug connector of the present invention has a structure in which the connector fittings are separated on the plug side and the cord side. (1) The total length of the two connector fittings is shortened to 40 mm or less, which prevents noise and reduces the (2) The resin sleeve prevents the cord from easily falling off, and (8) The plug terminal can be easily replaced with either a screw type or integral terminal nut type, reducing costs due to common parts. (4) The insulator head of the plug is 12Hφ
, 10aI can be used by simply replacing the rubber boots 8, and can be completely waterproof.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional view of the spark plug connector of the present invention, Fig.
The figure shows the first connector fitting, Fig. 2c&) is its side view, Fig. 2(b) is its front view, and Fig. 8 shows the second connector fitting. The figure (-) is a sectional view thereof, and FIG. 8(b) is a sectional view taken along the line A. 1... Wire-wound resistor cord 2... Synthetic resin sleeve 8... First connector fitting 5... Second connector fitting 7... Sgeling 8... Rubber boots patent applicant
Nippon Special Ceramics Co., Ltd.

Claims (1)

[Claims] In a noise prevention device for an ignition glove, which is formed by inserting a wire-wound resistance-containing cord into a synthetic resin sleeve and assembling the cord integrally, the first connector fitting having a protruding plate protruding from the front end is crimped in advance to the outer edge of the terminal portion. The synthetic resin sleeve is inserted and fixed from the other end of the wire-wound resistor cord through the lug side opening, and a plug terminal is housed inside the front end, and the other end is electrically connected to the protruding plate on the outer periphery. A second connector fitting provided with a spring is inserted into the sleeve from the plug-side opening and screwed onto the inside of the synthetic resin sleeve, and the total length of both connector fittings is regulated to be t40W or less, and the entire sleeve is A noise prevention device for a spark plug connector characterized by being covered with a tubular rubber boot.