JP2006132413A - Multi-point ignition plug built-in gasket - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multi-point ignition plug built-in gasket capable of retaining excellent characteristics such as sealing performance as organic material, insulation and mechanical strength for a long period of time. <P>SOLUTION: This gasket includes electric wiring 2 formed in a plane surface, organic material sheet 4 and conductive high heat conductivity sheet 5 laminated on both surfaces in this order, a tip part 3a projecting in a hole part side of a cylinder from the electric wiring 3, and a plurality of electric discharge gap 3 constructed by an edge part of a hole part side of the conductive high heat conductivity sheet 5 or heat resistant metal connected to the same. High voltage can be applied to the electric discharge gap via the electric wiring 2 and the conductive high heat conductivity sheet 5. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a multipoint ignition plug built-in gasket used for a multipoint ignition type internal combustion engine.

  The multipoint ignition engine (Patent Document 1) is said to have excellent features such as high fuel efficiency, high output, and low environmental pollution components in the exhaust gas. Since it is difficult to manufacture a gasket with a spark plug having various characteristics, commercialization has not yet been realized.

  In general, gaskets are exposed to high-temperature combustion gas, and therefore require high-temperature heat resistance of about 400 ° C. In addition to the pressure, temperature, viscosity, and other fluids such as combustion gas, lubricating oil, and cooling water. Sealing is required, and further, the cylinder head and the cylinder block are tightened with a strong force, so that mechanical strength sufficient to withstand this tightening force, that is, sag resistance, is required.

  Conventionally, artificial fibers, graphite, metal, and the like have been used as gasket materials that satisfy such required characteristics.

On the other hand, in the case of a gasket with a built-in spark plug, high voltage electrical wiring is disposed in the gasket, so that high electrical insulation is required in addition to these characteristics.
However, since the conventional gasket material described above is electrically conductive or has low electrical insulation, there is a problem that a necessary discharge voltage cannot be applied when used in a spark plug built-in type gasket.

An organic material such as a synthetic resin is known as a material excellent in electrical insulation and sealing properties, but the organic material can be a high temperature of about 400 ° C. even with the most heat-resistant polyimide resin or fluorine resin. If it is exposed, it will cause thermal degradation and the electrical insulation and sealing properties will be impaired, making it very difficult to design to withstand actual operation.
US Pat. No. 5,046,466

  As described above, conventional gasket materials have low conductivity and electrical insulation properties such as man-made fibers, graphite, and metal, so that when used for a spark plug built-in gasket, a necessary discharge voltage cannot be applied. There was a problem.

  In addition, organic materials such as synthetic resins are known as materials having excellent electrical insulation and sealing properties. However, organic materials such as polyimide resins and fluorine resins having the highest heat resistance may be around 400 ° C. If it is exposed to high temperatures for a long time, thermal degradation will occur, the insulation and sealing properties will be impaired, there is no durability for long-term use, and it is very difficult to design to withstand actual operation. It was.

  The present invention has been made to solve such a conventional problem. As a gasket material, an organic material having excellent electrical insulation and sealing properties is used, and a high thermal conductivity sheet is disposed so as to be in contact with these materials. The purpose is to provide a multi-point spark plug built-in gasket that can maintain excellent characteristics such as sealing performance, insulation and mechanical strength as an organic material over a long period of time by installing and improving heat dissipation To do.

  According to a first aspect of the present invention, there is provided a laminated gasket having a hole corresponding to an inner wall of a cylinder used by being sandwiched between a cylinder block and a cylinder head of an internal combustion engine. And an organic material sheet and a conductive high thermal conductivity sheet, which are sequentially laminated on both surfaces of the electrical wiring, a tip portion projecting from the electrical wiring to the hole side, and the conductive high thermal conductivity sheet. A plurality of discharge gaps composed of an edge on the hole side or a refractory metal connected thereto, and a high voltage is applied to the discharge gap via the electrical wiring and the conductive high thermal conductivity sheet It is configured to be possible.

  The material used for the organic material sheet in the present invention is a synthetic resin having a usable temperature of 300 ° C. or higher such as polyimide resin or fluorine resin, or a filler having good electrical insulation such as mica or silica in thermosetting resin. The curable synthetic resin composition which mix | blended these is mentioned.

  Examples of the material used for the conductive high thermal conductivity sheet in the present invention include conductive metals for electrical conductors such as copper and copper alloys, graphite, and the like.

Since the discharge electrode is particularly exposed to a high temperature, a heat-resistant alloy or other refractory metal used for a normal spark plug is suitable.
As the electrical wiring, a high resistance metal thin plate or the like can be used.

  The gasket with a built-in multipoint spark plug according to the present invention, for example, sandwiches an electrical wiring formed in advance with two organic material sheets molded in a predetermined shape, and further outside with a conductive high thermal conductivity sheet. It is obtained by laminating so as to be sandwiched and integrating by heating and pressing.

  In the present invention, the conductive high thermal conductivity sheet functions as a power feeding path for one of the discharge electrodes constituting the discharge gap. This conductive high thermal conductivity sheet may be only on one side as required.

According to a second aspect of the present invention, there is provided a laminated gasket having a hole corresponding to an inner wall of a cylinder used by being sandwiched between a cylinder block and a cylinder head of an internal combustion engine, wherein the gasket includes an organic material sheet and the organic material. Planarly formed electrical wiring and high thermal conductivity sheet, which are sequentially laminated on both surfaces of the sheet, and a refractory metal projecting on the opposing surface of the tip portion protruding from each electrical wiring to the hole side A plurality of discharge gaps configured,
A high voltage can be applied to the discharge gap via each electrical wiring.

  As the organic material sheet, the high thermal conductivity sheet, the discharge electrode, the electrical wiring, and the like in the second invention, the same materials as in the first invention can be used, but the high thermal conductivity sheet is not necessarily highly conductive. There is no need.

  Also in the present invention, the conductive high thermal conductivity sheet can be only one side as required.

  According to a third aspect of the present invention, there is provided a gasket having a hole corresponding to an inner wall of a cylinder used by being sandwiched between a cylinder block and a cylinder head of an internal combustion engine, wherein the gasket includes a plurality of groove portions extending from a peripheral edge to the hole. A sheet having a high thermal conductivity, at least a pair of electric wires insulated from each other via an organic material in each groove, and a metal conductor protruding from the electric wires toward the hole. And a high voltage can be applied to the discharge gap via the electric wires.

  In the gasket with a built-in multipoint spark plug according to the present invention, for example, a pair of insulated wires are arranged in the groove portion of the high thermal conductivity sheet, and a liquid thermosetting resin containing an inorganic filler is filled around the insulating wire. An organic material sheet is disposed on the substrate and cured by heating.

  The ends of these insulated wires on the hole side are connected to, for example, a discharge electrode made of a refractory metal constituting the discharge gap, and the refractory metal forms a discharge gap.

  According to a fourth aspect of the present invention, there is provided a gasket having a hole corresponding to an inner wall of a cylinder used by being sandwiched between a cylinder block and a cylinder head of an internal combustion engine. The gasket is divided into a plurality from a peripheral edge to the hole. A high thermal conductivity sheet, a joint portion made of an organic material having a substantially constant width that integrally joins the divided portions of the high thermal conductivity sheet, and at least a pair of electrical wirings embedded in the joint portion and insulated from each other. A plurality of discharge gaps constituted by metal conductors projecting from the respective electric wires toward the hole, and configured to be able to apply a high voltage to the discharge gaps through the electric wires. It is characterized by.

  In this invention, the high thermal conductivity sheet is divided into a plurality of pieces in the radial direction from the center, for example, and the divided pieces are arranged in the shape of a gasket at a predetermined interval, and the insulated wires are arranged between the divided pieces, and then divided. The part is formed by, for example, filling a liquid thermosetting resin mixed with an inorganic filler and curing it integrally.

  In each invention, since the vicinity of the discharge gap is exposed to high-temperature combustion gas, the portion exposed to the hole is preferably made of a heat-resistant material. Further, it is desirable to provide a heat shield portion for high-temperature combustion gas by covering a portion facing the hole portion of the organic material with a ceramic or a heat-resistant alloy plate. Further, the edge of the hole side of the high thermal conductivity sheet is bent inward, and the portion other than the discharge gap is covered with the high thermal conductivity sheet or other heat-resistant metal plate to reduce the influence of the combustion gas on the organic material. You may do it. Furthermore, when the organic material is a thermosetting synthetic resin, the portion facing the hole may be highly filled with mica to increase the heat resistance.

  According to the present invention, since the electrical wiring for ignition is configured to be insulated with the organic material, high dielectric strength can be obtained, and the heat transmitted to the organic material is released to the engine block body by the high thermal conductivity sheet. As a result, the temperature of the organic material can be lowered to 300 ° C or lower, and a gasket with a built-in multipoint spark plug that can maintain good electrical insulation and sealing performance over a long period of time and can withstand long-term engine operation. Can be provided.

  Hereinafter, the gasket embodiment with a built-in multipoint spark plug according to the present invention will be described in detail with reference to the drawings. The following embodiment is an example of a multi-point spark plug built-in gasket (applied voltage: 20 to 25 kV) for a 50 cc two-cycle engine, but it is of course applicable to other engines.

Example 1
1-5 is a figure for demonstrating embodiment of 1st invention.
As shown in FIG. 1, the gasket with a built-in multipoint spark plug of this embodiment has a main body portion 1 having a circular hole with an inner diameter of 30 mm in a rectangular central portion 1 a as in the joint surface between a cylinder head and a cylinder block of an internal combustion engine. The connection portion 2a connected to the high voltage circuit protrudes from the four corners of the central portion 1a, and four discharge gaps 3 are formed on the inner peripheral wall of the hole portion 1b. Is formed.

  As shown in an enlarged cross-sectional view in FIG. 2, the main body portion 1 has an electric wiring 2 for applying a high voltage to one discharge electrode 3a of the discharge gap 3, and has a temperature of 300 ° C. or higher such as polyimide on both sides. An organic material sheet 4 having a usable temperature of 0.3 mm and a conductive high thermal conductivity sheet 5 having a thickness of 0.4 mm, such as a copper plate, are sequentially laminated and integrated by heating and pressing to form an overall thickness. Is 1.8 mm.

  Since the inner wall surface of the hole 1b of the main body 1 is exposed to high-temperature combustion gas, a heat-resistant ring 6 having a thickness equal to that of the organic material sheet 4 is provided around the hole 1b as shown in FIG. Alternatively, as shown in FIG. 4, portions other than the discharge gap 3 may be covered with the same material as the high thermal conductivity sheet.

  As shown in FIG. 5, the electrical wiring 2 is formed from a thin plate of an annular high-resistance metal having a thickness of 0.4 mm, and connection terminals 2 a protrude from portions corresponding to the four corners of the outer periphery of the main body portion 1. One discharge electrode 3a that constitutes the discharge gap 3 protrudes from the inner portion that faces the hole.

  The discharge gap 3 is constituted by the inner peripheral edge 5a of the high thermal conductivity sheet 5 on the outer layer of the main body portion 1 and the discharge electrode 3a of the electric wiring 2, but separately discharges to the hole side of the high thermal conductivity sheet 5 as necessary. It is also possible to connect a refractory metal serving as an electrode.

Example 2
6-9 is a figure for demonstrating embodiment of 2nd invention.
As shown in FIG. 6, the gasket with a built-in multipoint spark plug of this embodiment is arranged so that the organic material sheet 4 is sandwiched between two electrical wires 2 and 2 and further is sandwiched between high thermal conductivity sheets 5. And formed integrally by heating and pressing. The discharge gap 3 of the gasket with a built-in multipoint spark plug is formed between the projections 6 and 6 made of a refractory metal projecting on the opposing surfaces of the electric wires 2 and 2.

  Also in the case of this invention, in order to avoid deterioration due to high-temperature combustion gas, a ring 7 made of ceramic is disposed around the hole 1b on the hole part side of the organic material sheet 4 as shown in FIG. Can do. As shown in FIG. 8, the protrusions 6 and 6 made of a refractory metal can be formed by shifting the position in the horizontal direction so that they do not come into contact with each other even if the electric wirings 2 and 2 fall.

  As shown in FIG. 9, the annular electrical wiring 2 in this multi-point spark plug built-in gasket is such that the connection terminal 2 a is led out from one place, and is a high electrode that becomes a discharge electrode at a predetermined position near the hole side of the electrical wirings 2 and 2. A protrusion 6 made of a melting point metal is formed.

Example 3
10-13 is a figure for demonstrating embodiment of 3rd invention.
As shown in FIG. 10, the gasket with a built-in multipoint spark plug according to this embodiment has a substantially rectangular copper plate 11a formed in a predetermined gasket shape, and the copper plate 11a is divided into four substantially at the center of the hole. A groove 11b is formed in an orthogonal direction, an insulated wire 12 having a flat conductor coated with a polyimide insulating coating is disposed in the groove 11b, and filled with a phenolic resin 13 containing an inorganic filler such as mica. The polyimide film 14 is coated and heated and cured.

In this embodiment, in order to protect the phenolic resin on the hole side from deterioration due to combustion gas, as shown in FIG. 11, the amount of mica is increased in order toward the hole side (13a, 13b, 13c and The blending amount of mica increases in order.) As shown in FIG. 12, a ceramic heat shield member 15 may be disposed on the hole side.
FIG. 13 shows a cross section taken along line XIII-XIII in FIG.

Example 4
FIG. 14 is a diagram for explaining an embodiment of the fourth invention.
The multi-point spark plug built-in gasket of this embodiment is the same as that in FIG. 10 when viewed from the top, but the bottom surface is divided into four parts, as shown in FIG. They are joined together by a phenolic resin blended with an agent.

  In this embodiment, the connecting portion of the groove portion of the copper plate 11a is completely removed and divided into four parts, and the four divided copper plates 11a 'are arranged in the shape of the original copper plate 11a with the interval of the groove portions, Insulated electric wires are arranged between them, and the divided portions are filled with, for example, a phenolic resin 13 blended with an inorganic filler and cured integrally.

  Also in this embodiment, in order to protect against deterioration due to combustion gas of the phenolic resin 13 on the hole side, as shown in FIG. 11, the amount of mica is increased sequentially toward the hole side, or as shown in FIG. In addition, a ceramic heat shield 15 can be disposed on the hole side.

The top view of 1st invention. The expanded sectional view which follows the II-II line of FIG. The expanded sectional view which shows the other form of the principal part shown in FIG. The expanded sectional view which shows the other form of the principal part shown in FIG. The top view which shows the electrical wiring of 1st invention. The expanded sectional view of the principal part of 2nd invention. The expanded sectional view of the important section of other embodiments of the 2nd invention. The expanded sectional view of the important section of other embodiments of the 2nd invention. The top view which shows the electrical wiring of 2nd invention. The top view of 3rd invention. The expanded longitudinal cross-sectional view of the principal part of 3rd invention. The expanded longitudinal cross-sectional view of the principal part of other embodiment of 3rd invention. The cross-sectional view of the principal part of 3rd invention. The transverse cross section of the important section of the 4th invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Body part, 1a ... Center part, 1b ... Hole part, 2 ... Electrical wiring, 2a ... Connection terminal, 2b ... Discharge electrode, 3 ... Discharge gap, 3a ... Discharge electrode, 4 ... ... Organic material sheet, 5 ... High thermal conductivity sheet, 6 ... Heat-resistant ring, 6a ... Projection, 11a, 11a '... Copper plate, 11b ... Groove, 12 ... Insulated wire, 13 ... Phenolic resin, 14: Polyimide film, 15: Heat shielding member.

Claims (8)

In a laminated gasket having a hole corresponding to an inner wall of a cylinder used by being sandwiched between a cylinder block and a cylinder head of an internal combustion engine,
The gasket is
Electrical wiring formed in a plane;
An organic material sheet and a conductive high thermal conductivity sheet, which are sequentially laminated on both sides of the electrical wiring,
A plurality of discharge gaps constituted by a tip portion protruding from the electrical wiring to the hole portion side and an edge portion on the hole portion side of the conductive high thermal conductivity sheet or a heat-resistant metal connected thereto;
A gasket with a built-in multipoint spark plug, wherein a high voltage can be applied to the discharge gap via the electrical wiring. In a laminated gasket having a hole corresponding to an inner wall of a cylinder used by being sandwiched between a cylinder block and a cylinder head of an internal combustion engine,
The gasket is
An organic material sheet,
A planarly formed electrical wiring and a high thermal conductivity sheet, which are sequentially laminated on both sides of the organic material sheet,
A plurality of discharge gaps made of a heat-resistant metal projecting on the facing surface of the tip portion projecting from the respective electrical wiring to the hole side,
A multi-point spark plug built-in gasket, characterized in that a high voltage can be applied to the discharge gap via each electrical wiring. In a gasket having a hole corresponding to an inner wall of a cylinder used by being sandwiched between a cylinder block and a cylinder head of an internal combustion engine,
The gasket is
A high thermal conductivity sheet formed with a plurality of grooves from the peripheral edge to the hole,
At least a pair of electrical wires insulated from each other disposed in each groove portion via an organic material;
A plurality of discharge gaps constituted by metal conductors protruding from the respective electric wirings toward the hole,
A multi-point spark plug built-in gasket, characterized in that a high voltage can be applied to the discharge gap via each electrical wiring. In a gasket having a hole corresponding to an inner wall of a cylinder used by being sandwiched between a cylinder block and a cylinder head of an internal combustion engine,
The gasket is
A high thermal conductivity sheet divided into a plurality from the periphery to the hole,
A joint portion made of an organic material having a substantially constant width for integrally joining the divided portions of the high thermal conductivity sheet; and
At least a pair of electrical wires embedded in the joint and insulated from each other;
A plurality of discharge gaps constituted by metal conductors projecting from the respective electrical wirings to the hole side,
A multipoint ignition plug built-in gasket, characterized in that a high voltage can be applied to the discharge gap via each electrical wiring.   5. The multipoint spark plug built-in gasket according to claim 3, wherein the metal conductor protruding toward the hole is made of a refractory metal.   The multi-point spark plug built-in gasket according to claim 3 or 4, wherein the electrical wiring is a flat insulated wire in which a flat conductor is covered with an insulating material having a higher electrical insulation than the organic material sheet.   The multipoint ignition according to any one of claims 1 to 6, wherein a heat shield portion made of a heat-resistant material for protecting the organic material sheet from combustion gas is formed at a base portion of the discharge gap. Plug built-in gasket.   The multi-point spark plug built-in gasket according to claim 7, wherein the heat shield portion is made of a ceramic material.

Images