JPS5859579A - 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 a spark plug used for internal combustion horizontal combustion.

As an electrode material for a spark plug of an automobile engine, an alloy (for example, Ni-2Mn-38i-2Cr) containing nickel with small amounts of manganese, silicon, and chromium is in practical use.

Although this alloy satisfies the characteristics required for the electrodes of spark plugs, there are still some points that need to be improved in order to meet the recent requirements for extending the lifespan of spark plugs that require strong water spraying.

As a result of conducting research from the viewpoint of wear resistance of spark plug electrodes, the inventor discovered that the high voltage electrode (center I
The factors that contribute to the oil content are not uniform between the E electrode and the ground electrode, so when one electrode is made up of a material, the secondary wear resistance is good, but when the other electrode is made of a material with φ diameter, it does not necessarily have good wear resistance. I discovered that it doesn't get better.

The present invention was made based on this knowledge.

By composing the center electrode and the ground electrode with different materials that have good wear resistance when each constitutes a pole, both electrodes are moldy and impurity content. mx with nickel or nickel-based alloy of less than 5 layers, preferably less than 2 layers, and the ground electrode with 1 layer of chromium.
The present invention relates to a spark plug characterized in that it is made of a nickel-based or iron-based alloy containing 0 to 50[31% by weight, preferably 15 to 40% by weight] and a cobalt-based alloy.

Suitable additive elements for the nickel-based alloy constituting the center electrode are those that improve oxidation resistance and heat resistance without reducing the thermal and electrical conductivity of nickel. Chromium, manganese, silicon, yztrium, aluminum, zirconitum. Titanium etc. can be used.

As the material for forming the center electrode, it is possible to use one of these alloys or pure nickel containing only unavoidable impurities.

The reason for limiting the content of additive elements and/or impurities contained in each electrode in the present invention as described above is as follows.

In other words, the center! In general, when the heat and gas conductivity of an electrode deteriorates, the amount of wear increases, but even in the present invention, when the content of additives and/or impurities exceeds 5% by weight, the wear resistance decreases. It becomes like this. - Since the ground electrode is protruded into the cylinder of an internal combustion engine and exposed to severe oxidation conditions, alloys with excellent oxidation resistance have less wear and tear, but the chromium content is less than 10% by weight. Then i
The saponification property becomes insufficient and the abrasion resistance decreases, and conversely, if the chromium content exceeds 50% by weight, the workability deteriorates.

2. When the chromium content is in the range of 10 to 50% by weight,
A nickel-based, iron-based, or cobalt-based base metal also exhibits excellent abrasion resistance and has good processing properties. FIG. 1 is a partial cross-sectional view of one embodiment of the spark plug of the present invention.

In the same figure, pole 1 in the center is composed of pure nickel or nickel with an As content of 4M having an additive element such as pure nickel and/or impurities of less than 5% by weight, and i
The electrode 2 is composed of a nickel-based, iron-based or cobalt-based alloy with a chromium content of 10 to 50% by weight. In the same figure, 3 is an insulator that covers the center electrode 1, 4 is a center terminal, 5 is a resistor, and 6 is a threaded part for mounting on the cylinder head of an internal combustion engine, which is one or more sets of the spark plug of the present invention made by &CII. is an additive element and/or with good thermal and electrical conductivity.
Or, it is made of pure nickel or nickel-based alloy with no impurity content, and the ground electrode is made of high chromium-poor nickel-based, iron-based, or cobalt-based alloy with good oxidation resistance.
Since the ignition plug is heated, the consumability of both electrodes is improved, and the life span of the spark plug as a whole can be significantly improved.

The implementation IP IIrc of the present invention will now be described.

1h Example A spark plug having the structure shown in FIG. 1 was manufactured using pure nickel or an alloy shown in the following table. Sample numbers 1 to 14 are centered;
Both ground electrodes are made of the same material. A loss test with these O plugs attached to the machine and a bench test simulating electrode wear on an actual machine were conducted, and the results are shown in the table. Note that the electrode wear amount and oxide layer thickness among the test items were measured in the following manner.

Wear Resistance Arc discharge was generated at 12,000 times/min between the center and ground electrodes through a Tsutomi ignition system at C5 hours/cIiJ in a high-pressure atmosphere, and the 100-hour test ukO volume loss was measured.

Attach the plug to be evaluated to the i1 oxidizing engine and run it at full speed (6000 rpm).
After operating for 100 hours at a rpm), the oxidation cruise thickness from the ground electrode surface was measured. However, the original ground electrode thickness frame 1.
4Ng'''C, oxide layer thickness 0.7W, the electrode fell off during the test due to oxidized RC.

Figure 2 shows the thickness of the coat and the violet inside the coat, which were made of pure nickel or nickel alloy. Demeru.

As is clear from the above-mentioned damage, the bleaching resistance of the spark plugs is to blame.
stone 1. <It's just a matter of getting started.

4. The 115th year of the 1st century, Figure 1 μ Akira Honji's Kazufuse 1 Tari's fXL minute 'dJf [
311, Fig. 2 shows nickel or nickel marking 5i
tt out fc % 'lIL'te 4'l one,
llr'i JJu 7C book jK '14 M &koi
BI LC, (100 hours Tsuekawa Kyoto's skeleton pigeon thickness and electric grudge fore l /1 < -f class 7.

1　°°°°゛Chumin''1lIIL pocket 2...J1#c earth electric disaster 3...loquat b", dedication ４・・・・・・Middle〕(Shiko 5...Paper enemy 6..

Claims (1)

[Scope of Claims] 1. The center electrode is made of nickel or nickel with a richness of minor elements and/or inorganic substances of 5 weight percent or less.
! The ground electrode is made of gold and contains 10 to 60% chromium by weight.
A spark plug that is made of a nickel-based, iron-based, or cobalt-based metal. 2. The spark plug described in item 5 of the patent-claimed invention, characterized in that the center electrode is made of a nickel-based alloy containing 2% by weight or less of additive elements and/or impurities. 3. The ground electrode is made of chromium. Item 1 or 2 of the claimed scope of the patent is characterized in that the alloy is made of an alloy consisting of 15 to 40% by weight, the balance being nickel, iron, cobalt, and impurities. A spark plug according to any one of claims 1 to 3.