JPH01283786A - Spark plug with built-in pressure sensor - Google Patents

Abstract

PURPOSE:To enhance the connection strength by furnishing extendedly connector parts, which is to be provided at the lead end of a pressure sensor to be inserted into a seat surface of the drum of a body metal piece, at the exposed portion of an insulating member. CONSTITUTION:A plurality of connector parts 10 are furnished in the form of a ring at the exposed portion of an insulating member 2 in order to take out output signals from a pressure sensor 6, which is fitted in an retained by a ring-shaped groove 5 in the drum part 4 of a body metal piece 3. Each connector part 10 is coated with metal paste and baked, and at the same time, other glass material is coated to prove insulation from the body metal piece 3. When a plug cap 12 is fitted to hold a lead 11, which is to put the pressure sensor 6 in continuity with a CPU for controlling combustion, easy connection is obtained because the connector part 10 extended from the pressure sensor 6 is provided at the exposed portion of the insulating member 2, which should enhance the reliability of continuity.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a spark plug incorporating a pressure sensor for controlling combustion in an internal combustion engine.

(Prior Art) In recent years, as the performance of internal combustion engines has improved, precise control within the combustion chamber of the internal combustion engine has become necessary. Therefore, the combustion pressure of the fuel generated in the combustion chamber is detected and measured by a pressure sensor built into the body of the spark plug, and the pressure is measured via a connector located on the shoulder or side of the body of the spark plug. , is connected to the CPU (computer) and controls combustion within the combustion chamber.

(Problem to be Solved by the Invention) However, in the above-mentioned conventional device, when the connector portion of the pressure sensor built into the body of the metal shell is disposed on the shoulder or side surface of the body of the metal shell, the pressure sensor is In order to reliably transmit the weak signals that are output to the CPU, the main metal fittings and the connector must be completely insulated, and the necessary work steps increase costs and reduce work efficiency. be. In addition, since the lead wire that connects the connector part and the CPU is inserted and held within the plug cap, it is necessary to cover the shoulder and side surfaces of the metal shell body where the connector part is installed with the plug cap. As a result, the plug cap may easily come off due to incomplete installation or stress during fitting.

Furthermore, due to the design of current internal combustion engines, the area that can be dedicated to the plug hole is quite limited, and there is almost no room for enlarging the size of the plug cap or the like. Therefore, the present invention aims to improve the drawbacks of the above-mentioned conventional devices, and aims to improve the reliability of conduction of the connector part even if it is provided in a limited area with a simple structure. Measures for Solving the Problem) To this end, the connector part of the lead wire of the pressure sensor built in the seating surface of the connecting part of the metal shell or the connecting part is provided on the exposed part of the insulator, or the insulator is exposed. A plurality of connector portions or an annular connector portion are provided in the portion, and the connector portion is further formed by attaching a metal paste.

(Function) Since the above structure is provided, when the plug cap for inserting and holding the lead wire that connects the CPU (computer) that controls combustion and the pressure sensor is inserted, the connector extending from the pressure sensor is inserted. Since the connector part is provided on the exposed part of the insulator, it can be easily connected, and since the connector part is attached with metal paste, it can be made into various shapes.

(Example) This invention will be further explained with reference to an example shown in the drawings. (1)
is a spark plug with a built-in pressure sensor which is an embodiment of the present invention, and this spark plug with a built-in pressure sensor (
1) is an annular groove (
The pressure sensor (6) is inserted into and held by the metal shell (3), which is further attached to the internal combustion engine, and includes a threaded part (7), an outer electrode (8), and a center electrode (9).
). In order to extract output signals from the pressure sensor (6) which is inserted and held in the annular groove (5) of the body (4) of the metal shell (3), a plurality of connector parts (lO) are connected to an insulator. The exposed portion (2) is provided in an annular shape. This connector part (10) is attached after applying a metal paste, and at the same time, insulation from the metal shell (3) is achieved by applying another glass material. For this reason, the signal output from the pressure sensor (6) is transmitted to the connector part (lO) provided on the exposed part of the insulator (2), and then sent to the CPU (computer) that controls combustion. Connect the plug cap (12) containing and holding the conductive lead wire (11) to the plug terminal (15) via the metal fitting (14).
When the terminal portion (13) of the lead wire (11) is fitted into the spark plug (1) and attached to the spark plug (1), the terminal portion (13) of the lead wire (11) is connected to the insulator (2).
) is in contact with the connector part (10) provided on the exposed part of the insulator (2), so the output signal is transmitted to the CPU (computer) (10) is a ring-shaped one (FIG. 3), or it may be provided on a semicircle or at two locations with different heights (FIG. 4).

(Effects of the Invention) As described above, by providing a connector part for a lead wire connected to a CPU (computer) on an exposed part of an insulator, and forming the connector part by applying metal paste and baking, the connector part This has the excellent effect of increasing the degree of freedom in design and thereby making it possible to improve connection strength.

[Brief Description of the Drawings] Fig. 1 is a partial sectional view of a spark plug with a built-in pressure sensor according to an embodiment of the present invention, Fig. 2 is an enlarged sectional view of the spark plug when the plug cap is attached, Figs. The figure is a partial sectional view of the second embodiment and the third embodiment. l... Spark plug with built-in pressure sensor 2... Insulator 3... Metal shell 4... Body 5... Annular groove
6... Pressure sensor 7... Threaded part 8... Outer electrode 9... Center electrode

Claims (4)

[Claims] (1) A spark plug with a built-in pressure sensor, in which a connector part provided at the end of a lead wire of a pressure sensor inserted into the body or seat of the metal shell extends to an exposed part of an insulator. (2) Claim (1) wherein a plurality of said connector parts or at least one or more connector parts are arranged in an annular shape on the insulator exposed part.
) spark plug with built-in pressure sensor. (3) Claim (1) When the plug cap is fitted to the exposed insulator part, the plug cap is electrically connected to the connector part.
) or (2) spark plug with built-in pressure sensor. (4) The spark plug with a built-in pressure sensor according to claim (1), (2) or (3), wherein the connector portion is baked on the exposed insulator portion by applying a metal paste and then firing it.