JPS60121690A - Pressure detector containing ignition plug - 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 spark plugs used in automobile internal combustion engines, and more specifically to spark plugs with built-in pressure detectors, and in particular to improvements in the connection part for extracting signals from the pressure detector. Conventionally, the connection part of a spark plug with a built-in pressure sensor has been designed to take out a signal from the pressure sensor directly to the outside of the spark plug housing through a lead wire, as described in Japanese Patent Laid-Open No. 13057-40887, for example. A terminal is installed at the tip.

[ ) or a groove in the housing,
There are some that take out a thin plate-like terminal through the groove. However, if the lead wire is directly taken out of the housing of the spark plug as in the former case, the lead wire and the terminated portion will get in the way when the spark plug with built-in pressure sensor is installed in the cylinder part of the internal combustion engine. In addition, by making a groove in the ignition housing as shown on the rear right and taking out the terminal through the groove, a part of the connector connected to the terminal can be installed in the rubber jacket of the high voltage cord key (7 tabs). However, when installing a spark plug with a built-in pressure detector into an internal combustion engine, accidents such as disconnection due to vibration during use can be prevented, but when installing the rubber jacket of the plug cap, make sure to align it with the terminal. In addition, since the hexagonal part of the housing is larger, the outer diameter of the cap rubber jacket is also larger than that for general spark plugs, and there is the inconvenience that additional machining is required, such as widening the spark plug insertion recess in the cylinder part. The present invention solves the above-mentioned inconveniences!The present invention has been made to solve the above-mentioned problems, and therefore, we provide a spark plug with a built-in pressure sensor that is small in size, easy to install in an internal combustion engine, and has the same tilt angle as a general spark plug. In order to achieve the above object, the ignition plug with a built-in pressure sensor of the present invention has a built-in pressure detector which has a built-in center electrode. ηt
1. A fixed annular terminal is provided on the head of the insulator to transmit the output horn signal of the pressure detector.
The connecting portion of the terminal is characterized in that it is installed in a rubber cap that integrally covers the area from the spark plug high-voltage cord to the upper surface of the hexagonal part of the spark plug housing so as to be in contact with the terminal. Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the spark plug 1 includes a metal housing 3 having a threaded portion 33 to be screwed into the cylinder head of an internal combustion engine, an insulator 2 such as an insulator housed within the housing 3, 1 = center electrode 15 insulated from the housing 3 by the insulator 2; a ground electrode 16 provided at the lower end of the housing 3 and facing the center electrode 15; and the housing 3
and an airtight packing 14 for airtightly fixing the insulator 2 and the insulator 2.
, and a crimping ring 13. Further, the housing 3 is provided with a hexagonal part 11 that serves as a plug wrench fitting part when screwed onto the cylinder head of an internal combustion engine, and a housing seat surface 35 that contacts the cylinder head when screwed is provided with a hexagonal part 11. , an annular groove 34 is provided, and a pressure sensor 4 formed into an annular shape and made of, for example, a piezoelectric element is installed in the annular groove 34 and fixed by welding a diaphragm 41 made of an annular thin metal plate. ing. A pressure introduction hole 31 is provided in the threaded portion 33 of the housing 3 to guide the combustion chamber pressure of the internal combustion engine (not shown) to the pressure detector 4.
A pressure introduction groove 32 is formed following the pressure introduction groove. The combustion chamber pressure of the internal combustion engine is determined by the pressure introduction hole 31 and the pressure introduction groove 32.
The electric signal is transmitted to the diaphragm 41 through the pressure sensor 4, which causes the pressure detector 4 to emit an electric signal. The connection part for taking out the signal from the pressure detector 4 consists of an output lead wire 5 from the pressure detector 4 and a terminal 6 fixed to the outer periphery of the head of the insulator 2. The output lead wire 5 is covered with a heat-resistant insulating material such as Teflon, and is connected to a lead hole 36, J3, and the insulator 2, which are provided in an annular groove 34 provided in the housing 3, facing the inner diameter hole in which the insulator 2 is housed. Connect the solder (
d, etc. (Terminal 6 is connected as shown in Fig. 2 (
As shown in (a) and (b), the ring is formed into an Iζ ring shape with one end open, and is fixed by being fitted into the S groove 22 provided on the outer periphery of the head of the insulator 2. The connection part of the terminal 6 is a metal n7 installed in a rubber cap 7 that integrally covers the high voltage cord 17 to the hexagonal part 1 of the housing 3 and the upper surface of the housing 3. It consists of: The high-voltage cord 17 is provided in the rubber cap 9 so as to be in close contact with a metal tube 10 that is fitted into a spark plug terminal portion 16 that protrudes from the end of the insulator 2 . Further, a lead wire 8 is connected to a metal tube 7 provided inside the rubber ring A7 knob 9 so that a signal can be taken out to the outside. Rubber cap 9
As shown above, the connection part of terminal 6, lead wire 5,
This prevents water and dust from entering the groove 21 for the lead wire 5 in the insulator 2. In the pressure detector built-in spark plug 1 of the above embodiment,
Central type t! i15 and has an insulator 2, and a pressure detector 4 is provided in an annular shape on a seat surface 35 of a metal spark plug housing holding the insulator 2. A fixed annular terminal 6 is provided so as to transmit the output signal of 4, and the connection part of the terminal 6 integrally covers the area from the spark plug high voltage cord 17 to the top surface of the hexagonal part 11 of the spark plug housing 3. Since it is installed in the rubber break 9 so as to be in contact with the terminal 6, the following effects can be obtained. (1) When installing the spark plug 1 at the head of the cylinder of an internal combustion engine, the lead wire J3 and the terminal are not installed outside, unlike conventional spark plugs with a built-in pressure detector, which can get in the way. There is nothing wrong with it, and it can be easily and quickly unscrewed just like a regular spark plug. (2) The terminal 6 is made of a thin metal plate formed into a ring shape, and the connecting part is also a metal tube 7 installed inside the rubber ring 11 knob 9, so the rubber ring A7 knob 9 must be installed in a special place. There is no need for cross-purchasing, and 1] can be easily and reliably done. (3) Rubber pad (up 9 is terminal 6, connection part,
Since it covers all the exposed parts of the spark plug 1, such as the lead wire 5 and the lead 21 provided on the insulator 2, it completely prevents water, dust, etc. from entering the main parts of the pressure detector 4.
can be done. In the above embodiment, the terminal 6 was shaped to be inserted into the groove 22 of the insulator 2, but as shown in FIG. It may be fitted there. In the above embodiment, the pressure saw detector 4 is of a type that operates by directly receiving the cylinder pressure, but the pressure sensor is of a type that operates by detecting changes in pressure applied to component parts. The same effect can also be obtained by installing it in a ring shape in the spark plug gasket or in the annular space between the insulator and the housing.As described above, the present invention Spark plugs with a built-in pressure detector can be made smaller by having a connection part for taking out the signal from the pressure detector installed in the rubber cap to make contact with the terminal installed in the head of the insulator. This has the advantage of being easy to install in an internal combustion engine and being compatible with general spark plugs.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a spark plug with a built-in pressure sensor which is an embodiment of the present invention, Fig. 2 shows a terminal used in the spark plug of Fig. 1, and Fig. 2 (a) is a plan view of the terminal. , FIG. 2(b) is a sectional view, and FIG. 3 is a sectional view of a main part showing another embodiment of the terminal. DESCRIPTION OF SYMBOLS 1... Spark plug, 2... Insulator, 3... Housing, 4... Pressure detector, 6... Terminal, 8...
...Rubber ring X7 knob, 11...Hexagonal part, 15...
Center electrode, 35...housing seating surface. Dai l! 11 people Asari Hiroshi 1 2 3: 3゜

Claims (1)

[Claims] An insulator with a built-in center electrode is placed on the right side, and a pressure detector is provided to detect the force in the combustion chamber of the internal combustion engine, and the nQ recording insulator is fixed to the head of the insulator so as to transmit the output signal of the pressure detector. An annular terminal is installed, and the connection part of the terminal is inside a rubber cap that integrally covers from the spark plug high voltage cord to the top of the hexagonal part of the spark plug housing.
A spark plug with a built-in pressure detector, characterized by the fact that it is installed in a contact hole with the terminal.