JPH0122472B2 - - Google Patents
Info
- Publication number
- JPH0122472B2 JPH0122472B2 JP56025408A JP2540881A JPH0122472B2 JP H0122472 B2 JPH0122472 B2 JP H0122472B2 JP 56025408 A JP56025408 A JP 56025408A JP 2540881 A JP2540881 A JP 2540881A JP H0122472 B2 JPH0122472 B2 JP H0122472B2
- Authority
- JP
- Japan
- Prior art keywords
- electrode
- discharge
- ignition
- rotor
- rotor electrode
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 25
- 239000000919 ceramic Substances 0.000 claims description 18
- 238000002485 combustion reaction Methods 0.000 claims description 14
- 229910010413 TiO 2 Inorganic materials 0.000 claims description 8
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 3
- 229910052739 hydrogen Inorganic materials 0.000 claims description 3
- 239000001257 hydrogen Substances 0.000 claims description 3
- 239000011224 oxide ceramic Substances 0.000 claims description 2
- 229910052574 oxide ceramic Inorganic materials 0.000 claims description 2
- 230000000694 effects Effects 0.000 description 18
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 14
- OKTJSMMVPCPJKN-YPZZEJLDSA-N carbon-10 atom Chemical compound [10C] OKTJSMMVPCPJKN-YPZZEJLDSA-N 0.000 description 5
- 230000005684 electric field Effects 0.000 description 5
- 239000000463 material Substances 0.000 description 5
- 230000015556 catabolic process Effects 0.000 description 4
- 229910052751 metal Inorganic materials 0.000 description 4
- 239000002184 metal Substances 0.000 description 4
- 229910001369 Brass Inorganic materials 0.000 description 3
- 239000010951 brass Substances 0.000 description 3
- 239000000843 powder Substances 0.000 description 3
- AZDRQVAHHNSJOQ-UHFFFAOYSA-N alumane Chemical class [AlH3] AZDRQVAHHNSJOQ-UHFFFAOYSA-N 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000010892 electric spark Methods 0.000 description 2
- 239000000446 fuel Substances 0.000 description 2
- 230000001939 inductive effect Effects 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 230000002265 prevention Effects 0.000 description 2
- 239000004065 semiconductor Substances 0.000 description 2
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 1
- ODINCKMPIJJUCX-UHFFFAOYSA-N Calcium oxide Chemical compound [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- CPLXHLVBOLITMK-UHFFFAOYSA-N Magnesium oxide Chemical compound [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- WNROFYMDJYEPJX-UHFFFAOYSA-K aluminium hydroxide Chemical compound [OH-].[OH-].[OH-].[Al+3] WNROFYMDJYEPJX-UHFFFAOYSA-K 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 238000001354 calcination Methods 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 238000006386 neutralization reaction Methods 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- -1 oxygen ions Chemical class 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 230000001629 suppression Effects 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02P—IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES
- F02P7/00—Arrangements of distributors, circuit-makers or -breakers, e.g. of distributor and circuit-breaker combinations or pick-up devices
- F02P7/02—Arrangements of distributors, circuit-makers or -breakers, e.g. of distributor and circuit-breaker combinations or pick-up devices of distributors
- F02P7/021—Mechanical distributors
- F02P7/025—Mechanical distributors with noise suppression means specially adapted for the distributor
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Ignition Installations For Internal Combustion Engines (AREA)
Description
【発明の詳細な説明】
本発明は電気火花点火式の内燃機関用点火配電
器に関し、特に、所定周期で対向するロータ電極
と側電極との間の放電に起因する雑音電波の波生
を抑制するようにしたものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electric spark ignition type ignition power distribution device for an internal combustion engine, and in particular, suppresses the generation of noise radio waves caused by discharge between a rotor electrode and a side electrode that face each other at a predetermined period. It was designed to do so.
電気火花点火式の内燃機関、例えば、自動車用
内燃機関の点火装置は、点火コイル、点火配電
器、点火プラグ等を有し、点火配電器あるいは点
火プラグにおける火花放電時に、立上り時間の急
峻な大電流が流れる。この火花放電に起因する雑
音電波は、テレビジヨン、ラジオ等の通信関係に
妨害を与える惧れがあり、一部の国においては、
この種の自動車から発生する雑音電波を法律で規
制している。 An ignition system for an electric spark ignition internal combustion engine, such as an automobile internal combustion engine, has an ignition coil, an ignition distributor, a spark plug, etc. Current flows. Noise radio waves caused by this spark discharge may interfere with communications such as television and radio, and in some countries,
The noise radio waves generated by this type of vehicle are regulated by law.
また、この種雑音電波は、通信関係に影響をお
よぼすばかりでなく、自動車等に搭載した電子機
器、例えば、電子制御燃料噴射装置、電子式アン
チスキツド装置、電子制御自動変速機に影響を与
え、自動車等の安全走行に支障をきたす惧れもあ
る。 In addition, this type of noise radio waves not only affect communications, but also affect electronic devices installed in automobiles, such as electronically controlled fuel injection devices, electronic anti-skid devices, and electronically controlled automatic transmissions. There is also a risk that this may impede safe driving.
このようなことから、火花点火装置から発生す
る雑音電波を低減することが要望されており、従
来種々の装置、機器が研究開発あるいは実用化さ
れている。 For this reason, there is a demand for reducing the noise radio waves generated from spark ignition devices, and various devices and devices have been researched and developed or put into practical use.
第１図は、火花点火装置に用いられる従来の点
火配電器の一例を示し、ここで、１はハウジング
であり、ハウジング１は、その内部に収容したカ
ム軸２とともに、内燃機関（図示せず）に装着さ
れている。カム軸２は内燃機関のクランク軸と連
動して回転し、ロータ３を駆動する。ロータ３は
カム軸２と連結した絶縁部材４と、絶縁部材４の
上面に固着した黄銅等から成るロータ電極５とを
有している。６はハウジング１に装着したキヤツ
プであり、その中央部に中央端子７を有し、周縁
部には内燃機関の気筒数に対応した数量の側電極
８を有している。中央端子７とロータ電極５との
間には、ばね９を介してセンターカーボン１０が
配設されており、センターカーボン１０は、ばね
９により、常時、ロータ電極５と圧接している。 FIG. 1 shows an example of a conventional ignition power distribution device used in a spark ignition device, where 1 is a housing, and the housing 1 is connected to an internal combustion engine (not shown) together with a camshaft 2 housed inside the housing. ). The camshaft 2 rotates in conjunction with the crankshaft of the internal combustion engine and drives the rotor 3. The rotor 3 has an insulating member 4 connected to the camshaft 2, and a rotor electrode 5 made of brass or the like fixed to the upper surface of the insulating member 4. Reference numeral 6 denotes a cap attached to the housing 1, which has a central terminal 7 at its center and side electrodes 8 at its periphery in a number corresponding to the number of cylinders of the internal combustion engine. A center carbon 10 is disposed between the center terminal 7 and the rotor electrode 5 via a spring 9, and the center carbon 10 is always in pressure contact with the rotor electrode 5 due to the spring 9.
このように構成した点火配電器において、点火
コイル（図示せず）で発生した高電圧は、高圧ケ
ーブル（図示せず）を介して中央端子７に供給さ
れる。この高電圧が、ばね９およびセンターカー
ボン１０を経てロータ電極５に導かれ、更に、ロ
ータ電極５と側電極８とが対向する度毎に、ロー
タ電極５に導かれた高電圧がロータ電極５の先端
部１１と側電極８との間の放電ギヤツプＧの空気
を絶縁破壊し、これにより側電極８に高電圧が配
電される。次いで、高圧ケーブル（図示せず）を
介して点火プラグに高電圧が供給される。 In the ignition distributor configured in this way, high voltage generated in the ignition coil (not shown) is supplied to the central terminal 7 via a high voltage cable (not shown). This high voltage is guided to the rotor electrode 5 via the spring 9 and the center carbon 10, and each time the rotor electrode 5 and the side electrode 8 face each other, the high voltage introduced to the rotor electrode 5 is introduced to the rotor electrode 5. The dielectric breakdown occurs in the air in the discharge gap G between the tip 11 and the side electrode 8, and as a result, a high voltage is distributed to the side electrode 8. High voltage is then supplied to the spark plug via a high voltage cable (not shown).
ロータ電極５と側電極８との間の点火放電現象
を更に詳述する。すなわち、点火コイルから供給
される高電圧はステツプ状に最高値に達するので
はなく、点火コイルや高圧ケーブル等の回路定数
によつて定まる時定数で上昇する。そして、高電
圧値が放電ギヤツプＧに火花放電を生ずるに十分
な値まで上昇したとき、放電ギヤツプＧの空気に
絶縁破壊が生じて火花放電が生ずる。 The ignition discharge phenomenon between the rotor electrode 5 and the side electrode 8 will be explained in more detail. That is, the high voltage supplied from the ignition coil does not reach its maximum value in steps, but increases with a time constant determined by circuit constants of the ignition coil, high voltage cable, etc. Then, when the high voltage value rises to a value sufficient to cause a spark discharge in the discharge gap G, dielectric breakdown occurs in the air in the discharge gap G, causing a spark discharge.
この場合、高電圧が上述した値に達したときに
急激な絶縁破壊が生ずるため、放電電流は短かい
パルス幅で急激に流れ、かつ尖頭値の高い不安定
な電流となるので、有害な高周波成分が多量に発
生し、これが高圧ケーブル等をアンテナとして外
部に放射されて雑音電波となる。 In this case, when the high voltage reaches the above-mentioned value, rapid dielectric breakdown occurs, and the discharge current flows rapidly with a short pulse width and becomes an unstable current with a high peak value, which is harmful. A large amount of high-frequency components are generated, which are radiated to the outside using high-voltage cables as antennas and become radio noise.
一般に、この種火花放電に起因して雑音源から
放射される雑音電界は、雑音電流に比例すると考
えられている。このため雑音電波の発生を抑制す
るには、ロータ電極と側電極との間の放電ギヤツ
プを流れる容量放電電流を減少させる必要があ
る。ここで、容量放電電流とは、放電ギヤツプ近
傍の電極等と接地との間の浮遊容量等に蓄積され
た電荷が、絶縁破壊時に高速（数ナノ秒程度）で
かつ急激な立上りで流れるものをいう。 It is generally believed that the noise electric field radiated from the noise source due to this seed spark discharge is proportional to the noise current. Therefore, in order to suppress the generation of noise radio waves, it is necessary to reduce the capacitive discharge current flowing through the discharge gap between the rotor electrode and the side electrode. Here, the capacitive discharge current refers to the charge accumulated in the stray capacitance between the electrode, etc. near the discharge gap and the ground, which flows at high speed (about a few nanoseconds) and with a sudden rise at the time of dielectric breakdown. say.
そこで、点火配電器における雑音電波の発生を
抑制するため、以下(A)〜(C)に述べる対策が提案さ
れている。 Therefore, in order to suppress the generation of noise radio waves in the ignition distributor, the measures described in (A) to (C) below have been proposed.
(A) ロータ電極に抵抗を配設したもの
これは、センターカーボン１０とロータ電極
５の先端部１１との間のロータ電極５に抵抗体
を埋め込んだものである。(A) A resistor is provided in the rotor electrode This is a resistor embedded in the rotor electrode 5 between the center carbon 10 and the tip 11 of the rotor electrode 5.
(B) 放電ギヤツプを大きしたもの
これは、ロータ電極５と側電極８との間の放
電ギヤツプＧを大きくしたもので、例えば従来
0.75mm程度の放電ギヤツプＧを1.524〜6.35mm程
度としたものである。(B) Larger discharge gap This is a larger discharge gap G between the rotor electrode 5 and the side electrode 8.
The discharge gap G, which is about 0.75 mm, is set to about 1.524 to 6.35 mm.
(C) ロータ電極の近傍に第３電極を配設したもの
ロータ電極５に誘電体を介して第３電極をと
りつけ、ロータ電極５が側電極８に接近したと
きに、まず第３電極と側電極８との間で火花放
電させ、その先駆放電によつて、ロータ電極５
と側電極８との間で放電させるようにしたもの
である。(C) A third electrode arranged near the rotor electrode The third electrode is attached to the rotor electrode 5 through a dielectric, and when the rotor electrode 5 approaches the side electrode 8, the third electrode and the side A spark discharge is caused between the electrode 8 and the rotor electrode 5 due to the pioneer discharge.
The electric discharge is caused between the side electrode 8 and the side electrode 8.
しかしながら、(A)〜(C)の従来の提案は次のよう
な欠点をそれぞれ有している。 However, the conventional proposals (A) to (C) each have the following drawbacks.
(A)については、抵抗体と並列をなす浮遊容量の
ため、300MHz程度以上の高周波帯域に対する雑
音抑制効果が小さい。 Regarding (A), due to the stray capacitance in parallel with the resistor, the noise suppression effect for high frequency bands of about 300 MHz or higher is small.
(B)については、雑音防止効果（基準とする雑音
電界強度に比べてどの程度雑音電界強度を低域で
きるかという効果）は10dB以上と優れているが、
点火エネルギー損失が極めて大きくなつてしま
う。そのため、近年の排気浄化や燃費向上にとつ
て不可欠な確実な着火が損なわれる惧れもある。
また、着火を確実にするために従来より高い電圧
を用いると、高電圧のリーク対策が難しくなる。 Regarding (B), the noise prevention effect (the effect of how low the noise field strength can be compared to the reference noise field strength) is excellent at 10 dB or more.
Ignition energy loss becomes extremely large. Therefore, there is a risk that reliable ignition, which is essential for exhaust purification and improved fuel efficiency in recent years, may be impaired.
Furthermore, if a higher voltage than conventional ones is used to ensure ignition, it becomes difficult to take measures against high voltage leaks.
(C)については、構造が複雑となり、かつ長期的
な信頼性に問題がある。 Regarding (C), the structure is complicated and there are problems with long-term reliability.
本発明の目的は、このような従来の欠点を除去
し、十分な雑音防止効果を発揮して、雑音電波の
発生を抑制した内燃機関用点火配電器を提供する
ことにある。 SUMMARY OF THE INVENTION An object of the present invention is to provide an ignition power distribution device for an internal combustion engine that eliminates such conventional drawbacks, exhibits a sufficient noise prevention effect, and suppresses the generation of noise radio waves.
すなわち、本発明点火配電器は、ロータ電極お
よび側電極の一方または双方の少なくとも先端の
放電部をアルミナを主体とする酸化物セラミツク
スにTiO2を添加し、水素を含む還元雰囲気中で
還元処理をおこなつて得られる半導電性のアルミ
ナ・セラミツクスで形成したことを特徴とするも
のである。 That is, in the ignition distributor of the present invention, the discharge portion at least at the tip of one or both of the rotor electrode and the side electrode is made of alumina-based oxide ceramics with TiO 2 added and subjected to reduction treatment in a reducing atmosphere containing hydrogen. It is characterized by being made of semiconductive alumina ceramics obtained by this process.
以下に図面に基づいて本発明を詳細に説明す
る。 The present invention will be explained in detail below based on the drawings.
第２図Ａ，ＢおよびＣは本発明内燃機関用点火
配電器に用いるロータ電極の諸例を示し、第２図
Ｄはその側電極の一例を示す。第２図Ａにおい
て、２１はロータ電極である。ロータ電極２１は
その全体を半導電性アルミナ・セラミツクスで形
成した例である。また、第２図Ｂにおいて、３１
はロータ電極であり、ロータ電極３１の場合は、
その先端放電部３１Ａのみを半導電性アルミナ・
セラミツクスで形成し、放電部３１Ａに連接する
残余の部分３１Ｂを金属材料で形成する。更にま
た、第２図Ｃにおいて、４１はロータ電極であ
り、ロータ電極４１の場合は、全体を半導電性ア
ルミナ・セラミツクスで形成した上、センターカ
ーボン１０に接触する部分に金属板４１Ａを固着
する。第２図Ｄにおいて、５１は側電極である。
この側電極５１は、その先端の放電部５１Ａのみ
を半導電性アルミナ・セラミツクスで形成したも
のである。 2A, B and C show various examples of rotor electrodes used in the ignition distributor for internal combustion engines of the present invention, and FIG. 2D shows an example of the side electrodes. In FIG. 2A, 21 is a rotor electrode. The rotor electrode 21 is an example in which the entirety is made of semiconductive alumina ceramics. Also, in Figure 2B, 31
is the rotor electrode, and in the case of the rotor electrode 31,
Only the tip discharge part 31A is made of semiconductive alumina.
The remaining portion 31B connected to the discharge portion 31A is formed from a metal material. Furthermore, in FIG. 2C, 41 is a rotor electrode, and in the case of the rotor electrode 41, the whole is made of semiconductive alumina ceramics, and a metal plate 41A is fixed to the part that contacts the center carbon 10. . In FIG. 2D, 51 is a side electrode.
In this side electrode 51, only the discharging portion 51A at the tip thereof is formed of semiconductive alumina ceramics.
次に、半導電性アルミナ・セラミツクスの製造
方法例について説明する。 Next, an example of a method for manufacturing semiconductive alumina ceramics will be described.
まず、水酸化アルミニウム等のアルミニウム塩
を熱分解して得られる粉末もしくはアルミニウム
塩を〓焼して得られるアルミナ粉末に、結合材と
してのマグネシア（MgO）、シリカ（SiO2）もし
くはカルシア（CaO）等を混入し、更に導電性を
持たせるためにチタニア（TiO2）を少量添加し
たものをよく混合練り合せた後、2000℃以上の高
温の酸化雰囲気中で焼結を行つた。ただし、この
状態のままでは未だ導電性は付与されない。そこ
で得られた焼結体を、水素を含む窒素還元性の
1500〜2000℃の雰囲気中に置いて10時間から48時
間程度の還元処理をしたところ半導電性を有する
アルミナ・セラミツクスが得られた。 First, magnesia (MgO), silica (SiO 2 ), or calcia (CaO) as a binder is added to powder obtained by thermally decomposing aluminum salt such as aluminum hydroxide or alumina powder obtained by calcining aluminum salt. A small amount of titania (TiO 2 ) was added to make the material conductive, and the mixture was thoroughly mixed and kneaded, and then sintered in an oxidizing atmosphere at a high temperature of 2000° C. or higher. However, in this state, conductivity is not yet imparted. The resulting sintered body is treated with a nitrogen-reducing solution containing hydrogen.
When the material was placed in an atmosphere of 1,500 to 2,000°C and subjected to reduction treatment for about 10 to 48 hours, semiconductive alumina ceramics were obtained.
このようなアルミナ・セラミツクスにおける導
電性は、TiO2が還元されて半導体となつたため
であり、その導電率は雰囲気温度と処理時間によ
る還元の度合によつてある程度調整することが可
能であつた。チタニア（TiO2）は化学量論的な
組成がずれ易く、従つて還元され易いことが知ら
れている。TiO2が還元されて半導体となつたの
は、TiO2が還元されるときに酸素イオンが失わ
れるので、残された余剰の電子が移動性を持ち、
金属結晶内における電子伝導と同様な現象を呈す
るためと考えられる。また、上述した原因の外
に、例えばSb5+のような４価よりも大きい原子
価を持つイオンがセラミツクス中に不純物として
介在している場合には、Ti4+のイオンが格子内
の電気的中和を維持するために強制的に３価の状
態Ti3+に変化させられ、その結果として還元し
たと同様な効果をセラミツクスの電気的性質に与
えるものと考えることもできる。 Such conductivity in alumina ceramics is due to the reduction of TiO 2 to become a semiconductor, and the conductivity could be adjusted to some extent by the degree of reduction depending on the ambient temperature and treatment time. It is known that titania (TiO 2 ) tends to have a stoichiometric composition and is therefore easily reduced. TiO 2 is reduced and becomes a semiconductor because oxygen ions are lost when TiO 2 is reduced, and the remaining surplus electrons become mobile.
This is thought to be due to a phenomenon similar to that of electron conduction within a metal crystal. In addition to the above-mentioned causes, if ions with a valence higher than 4, such as Sb 5+ , are present as impurities in the ceramic, Ti 4+ ions may be affected by the electricity in the lattice. In order to maintain target neutralization, Ti 3+ is forcibly changed to the trivalent state, and as a result, it can be considered that the same effect as reduction is given to the electrical properties of ceramics.
すなわち、得られた半導電性アルミナ・セラミ
ツクスにおいては、アルミナの高抵抗部分と、ア
ルミナとチタニアとの半導電性の固溶体部分と、
チタニアの半導電性部分とが入り混つて分散した
構造を有していると考えられる。このようなこと
から、チタニアの添加量および還元処理条件を変
えて所望の電気的性質を有する半導電性のアルミ
ナ・セラミツクスを得ることができる。 That is, in the obtained semiconductive alumina ceramics, a high resistance part of alumina, a semiconductive solid solution part of alumina and titania,
It is thought that it has a structure in which semiconductive parts of titania are mixed and dispersed. For this reason, semiconductive alumina ceramics having desired electrical properties can be obtained by changing the amount of titania added and the reduction treatment conditions.
このようにして得た半導電性のアルミナ・セラ
ミツクスを上述した例のように用いてロータ電極
２１〜４１や側電極５１を形成することにより、
電極の放電端面がミクロ的には細分化された導電
性要素と高抵抗性要素とで構成されることとな
り、またマクロ的に見れば電極母材が電気抵抗性
を有することとなつて、配電器における雑音電波
の発生を従来より著しく抑制することができる。 By forming the rotor electrodes 21 to 41 and the side electrodes 51 using the semiconductive alumina ceramics thus obtained as in the example described above,
Microscopically, the discharge end face of the electrode is composed of finely divided conductive elements and high-resistance elements, and macroscopically, the electrode base material has electrical resistance. The generation of noise radio waves in electrical appliances can be significantly suppressed compared to conventional methods.
ここで、放電電極に半導電性のアルミナ・セラ
ミツクスを用いることによつて雑音電波の発生が
抑制される理由について詳述する。 Here, the reason why the generation of noise radio waves is suppressed by using semiconductive alumina ceramics for the discharge electrode will be explained in detail.
この理由としては、次の２つの作用によるもの
と考えられる。すなわち、
(1) 放電電極の材料が半導電性すなわち電気抵抗
を有するために、対地浮遊静電容量と電極抵抗
とによりＲ−Ｃフイルタが形成されるので急峻
な変化をする容量放電電流の立上りがなまつて
くることによる。 This is thought to be due to the following two effects. That is, (1) Since the material of the discharge electrode is semiconductive, that is, has electrical resistance, an R-C filter is formed by the ground floating capacitance and the electrode resistance, so the rise of the capacitive discharge current changes sharply. It depends on how long it takes.
(2) 電極の放電端面におけるマクロ的構成要素が
導電性を有するチタニア（TiO2）と高抵抗性
を有するアルミナ（Al2O3）とに細分化されて
いるために先駆放電効果（Pre Ignition
effect）もしくはマルター効果（Malter
effect）が得られることによる。(2) The macroscopic constituent elements on the discharge end surface of the electrode are subdivided into titania (TiO 2 ), which has conductivity, and alumina (Al 2 O 3 ), which has high resistance, resulting in a pre-ignition effect.
effect) or Malter effect (Malter effect)
effect).
なお、ここで先駆放電効果とは、ロータ電極や
側電極においてこれら表面の局部的な高抵抗層に
電極の極性とは逆の電荷が静電力のために捕捉さ
れ、この捕捉された空間電荷によつて電極面に高
電界が発生し、ロータ電極と側電極の間に主放電
に先行して放電が行われ、この先駆放電によつて
放電開始電圧が低下することをいう。 Note that the pioneer discharge effect here refers to the fact that charges opposite to the polarity of the electrodes are captured by electrostatic force in the local high-resistance layers on the surfaces of the rotor electrodes and side electrodes, and this captured space charge Therefore, a high electric field is generated on the electrode surface, and a discharge occurs between the rotor electrode and the side electrode prior to the main discharge, and the discharge starting voltage is lowered by this pioneer discharge.
また、マルター効果とは、一般に、非導電性の
薄膜で表面を被覆した金属導体における電子放出
がおこりやすい現象をいい、負電極から直接電子
が放出されやすくなると、放電開始電圧が低下す
る。 Furthermore, the Malter effect generally refers to a phenomenon in which electron emission tends to occur in a metal conductor whose surface is coated with a non-conductive thin film, and when electrons are easily emitted directly from the negative electrode, the firing voltage decreases.
第３図は従来例の点火配電器および本発明点火
配電器をそれぞれ使用したときの電極における放
電電流の時間的変化波形を測定したものである。
ここでは横軸を時間とし、縦軸を放電電流とす
る。また、従来例の点火配電器としては、ロータ
電極５を黄銅板で形成し、側電極とアルミニウム
で形成したものを用いた。更にまた、本発明点火
配電器にはロータ電極のみを半導電性アルミナ・
セラミツクスで形成したものと側電極のみを半導
電性アルミナ・セラミツクスで形成したものの双
方について測定したが両者間に殆んど差異が認め
られなかつたので一本の線で示すこととした。破
線で示す波形Ａは従来例の点火配電器によるもの
であり、実線で示す波形Ｂは本発明点火配電器に
よるものである。 FIG. 3 shows the measured waveforms of the discharge current over time in the electrodes when using the conventional ignition distributor and the ignition distributor of the present invention.
Here, the horizontal axis is time and the vertical axis is discharge current. Further, as a conventional ignition distributor, one in which the rotor electrode 5 was formed of a brass plate and the side electrodes were formed of aluminum was used. Furthermore, in the ignition distributor of the present invention, only the rotor electrode is made of semiconductive alumina.
Measurements were made for both the electrode made of ceramics and the electrode made of semiconductive alumina ceramics, but almost no difference was observed between the two, so it was decided to show it as a single line. A waveform A shown by a broken line is obtained by the conventional ignition distributor, and a waveform B shown by a solid line is obtained by the ignition distributor of the present invention.
このように、従来例の点火配電器では、破線Ａ
に示すように、火花放電電流の波形が鋭いピーク
を有し短時間に大電流の流れたことを示している
のに対して、本発明実施例の点火配電器では、実
線Ｂに示すように、放電電流の立上りが緩やかで
あり尖頭値も低く、以て、有害な高周波成分に起
因する雑音電波の発生が有効に抑制されているこ
とが示されている。 In this way, in the conventional ignition distributor, the broken line A
As shown in , the waveform of the spark discharge current has a sharp peak, indicating that a large current flows in a short period of time. It has been shown that the rise of the discharge current is gradual and the peak value is low, thereby effectively suppressing the generation of radio noise caused by harmful high frequency components.
第４図は上述の測定に用いた従来例の点火配電
器および本発明実施例の点火配電器をそれぞれ一
般の車輌に実装して各周波数における雑音電波の
電界強度を測定した結果を示すものである。本図
において、横軸は周波数を示し、縦軸は雑音低域
効果を示す。 Figure 4 shows the results of measuring the electric field strength of noise radio waves at each frequency by mounting the conventional ignition distributor used in the above measurements and the ignition distributor according to the embodiment of the present invention in a general vehicle. be. In this figure, the horizontal axis shows the frequency, and the vertical axis shows the noise low-frequency effect.
ここで、従来の点火配電器を実装した場合の電
界強度を基準値0dBとして破線Ａで示し、実線Ｂ
は本発明点火配電器による電界強度を基準値と比
較して示したものである。この周波数スペクトラ
ム図に示される如く、本発明実施例の点火配電器
を実装した場合においては、30MHzから1000MHz
にわたり、おおよそ10dBから15dB程度の雑音低
減効果のあることが分る。また、図示してはいな
いが、放電電圧を測定したところ、従来例による
場合は放電開始電圧が約12kVであつたのに対し
て、本発明実施例による場合は放電開始電圧を５
〜8kV程度にまで低下させることができ、しかも
誘導放電時におけるロータ電極と側電極間の電圧
（電極抵抗分による電圧降下と誘導放電電圧の和）
や誘導放電継続時間については両者間に大きい差
異のないことが確認された。 Here, the electric field strength when a conventional ignition power distribution device is installed is shown as a reference value of 0 dB by a broken line A, and a solid line B
1 shows the electric field strength produced by the ignition distributor of the present invention in comparison with a reference value. As shown in this frequency spectrum diagram, when the ignition power distributor according to the embodiment of the present invention is implemented, the frequency range is from 30MHz to 1000MHz.
It can be seen that there is a noise reduction effect of about 10dB to 15dB across the range. Although not shown in the figure, when the discharge voltage was measured, it was found that the discharge starting voltage was approximately 12 kV in the case of the conventional example, whereas the discharge starting voltage was approximately 5 kV in the case of the embodiment of the present invention.
The voltage between the rotor electrode and the side electrode during inductive discharge can be reduced to ~8kV (sum of the voltage drop due to electrode resistance and the induced discharge voltage).
It was confirmed that there was no large difference between the two in terms of the duration of the induced discharge and the duration of the induced discharge.
すなわち、本願人は種々の実験により、半導電
性アルミナ・セラミツクス電極を用いた本発明内
燃機関用点火配電器が、優れた雑音低減効果を有
し、しかも点火エネルギーの損失は従来の黄銅製
電極を用いた点火配電器に比しても問題とするに
足りない程度であることを確認した。更にまた、
本発明点火配電器を用いると、従来例による場
合、誘導放電中に現われて殊にFMラジオに妨害
を与えていたような間欠放電も認められなくなつ
た。このこともまた、電極を半導電性アルミナ・
セラミツクスとしたことによる電極表面のミクロ
的構造や材料における抵抗性によるものと考えら
れる。 In other words, through various experiments, the applicant has found that the ignition distributor for internal combustion engines of the present invention using semiconductive alumina ceramic electrodes has an excellent noise reduction effect, and that the loss of ignition energy is lower than that of conventional brass electrodes. It was confirmed that this was not enough to cause a problem compared to an ignition distributor using Furthermore,
When the ignition distributor of the present invention is used, intermittent discharges, which appeared during inductive discharges and caused interference especially to FM radio in the conventional case, were no longer observed. This also means that the electrodes are made of semiconducting alumina.
This is thought to be due to the microstructure of the electrode surface and the resistance of the material due to the use of ceramics.
以上説明してきたように、本発明によれば、ア
ルミナ粉末に少なくともチタニアを添加し熱処理
して得られた半導電性のアルミナ・セラミツクス
を用いてロータ電極や側電極を形成することによ
り、放電電極における電気抵抗性や先駆放電効果
もしくはマルター効果が得られ、以て、放電電流
の立上りの尖頭を低下させることができ、雑音電
波の発生を抑制することができる。 As explained above, according to the present invention, the rotor electrode and the side electrodes are formed using semiconductive alumina ceramics obtained by adding at least titania to alumina powder and heat treating the discharge electrode. The electrical resistance and the pioneer discharge effect or Malter effect can be obtained, thereby making it possible to reduce the peak of the rise of the discharge current and suppress the generation of noise radio waves.
第１図は従来の内燃機関用点火配電器の構成の
一例を示す断面図、第２図Ａ，ＢおよびＣは本発
明内燃機関用点火配電器に用いるロータ電極のそ
れぞれ実施例を示す斜視図、第２図Ｄはその側電
極の実施例を示す斜視図、第３図は従来例の配電
器および本発明点火配電器を用いて放電電極にお
ける放電電流の時間に対する変化波形を測定した
結果を比較して示す波形図、第４図は本発明点火
配電器を用いた場合の電波雑音低域効果を従来例
の点火配電器を用いた場合に比較して示す周波数
線図である。
１……ハウジング、２……カム軸、３……ロー
タ、４……絶縁部材、５……ロータ電極、６……
キヤツプ、７……中央端子、８……側電極、９…
…ばね、１０……センターカーボン、１１……先
端部、Ｇ……ギヤツプ、２１，３１，４１……ロ
ータ電極、３１Ａ……先端放電部、３１Ｂ……残
余の部分、４１Ａ……金属板、５１……側電極、
５１Ａ……放電部。
FIG. 1 is a sectional view showing an example of the configuration of a conventional ignition power distribution device for an internal combustion engine, and FIGS. 2A, B, and C are perspective views showing respective examples of rotor electrodes used in the ignition power distribution device for an internal combustion engine of the present invention. , FIG. 2D is a perspective view showing an embodiment of the side electrode, and FIG. 3 shows the results of measuring the change waveform of the discharge current with respect to time in the discharge electrode using the conventional distributor and the ignition distributor of the present invention. FIG. 4 is a frequency diagram showing the radio noise low frequency effect when using the ignition power distribution device of the present invention in comparison with the case where the conventional ignition power distribution device is used. DESCRIPTION OF SYMBOLS 1... Housing, 2... Camshaft, 3... Rotor, 4... Insulating member, 5... Rotor electrode, 6...
Cap, 7...center terminal, 8...side electrode, 9...
...Spring, 10...Center carbon, 11...Tip, G...Gap, 21, 31, 41...Rotor electrode, 31A...Tip discharge section, 31B...Remaining part, 41A...Metal plate, 51...side electrode,
51A...discharge section.
Claims (1)
極と、該ロータ電極と所定のギヤツプを介して対
向する複数個の側電極とを有し、点火コイルから
発生した高電圧を前記ロータ電極と前記側電極間
の放電を介して該側電極に接続された点火プラグ
に給配電するように構成した内燃機関用点火配電
器において、前記ロータ電極および側電極のうち
少なくとも一方の少なくとも先端部を、アルミナ
を主体とする酸化物セラミツクスにTiO2を添加
し、水素を含む還元雰囲気中で還元処理をおこな
つて得られる半導電性アルミナ・セラミツクスで
形成したことを特徴とする内燃機関用点火配電
器。1. It has a rotor electrode that rotates in conjunction with the rotation of the internal combustion engine, and a plurality of side electrodes that face the rotor electrode through a predetermined gap, and the high voltage generated from the ignition coil is transferred between the rotor electrode and the side electrode. In an ignition distributor for an internal combustion engine configured to supply and distribute power to a spark plug connected to a side electrode via discharge between the side electrodes, at least the tip of at least one of the rotor electrode and the side electrode is made of alumina. An ignition power distribution device for an internal combustion engine, characterized in that it is formed from semiconductive alumina ceramics obtained by adding TiO 2 to oxide ceramics mainly composed of oxides and performing a reduction treatment in a reducing atmosphere containing hydrogen.
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2540881A JPS57140563A (en) | 1981-02-25 | 1981-02-25 | Ignition distributor for internal combustion engine |
| US06/346,744 US4419547A (en) | 1981-02-25 | 1982-02-08 | Ignition distributor for internal combustion engine |
| DE3206790A DE3206790C2 (en) | 1981-02-25 | 1982-02-25 | Ignition distributor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2540881A JPS57140563A (en) | 1981-02-25 | 1981-02-25 | Ignition distributor for internal combustion engine |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS57140563A JPS57140563A (en) | 1982-08-31 |
| JPH0122472B2 true JPH0122472B2 (en) | 1989-04-26 |
Family
ID=12165083
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2540881A Granted JPS57140563A (en) | 1981-02-25 | 1981-02-25 | Ignition distributor for internal combustion engine |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS57140563A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0635637A1 (en) * | 1993-07-22 | 1995-01-25 | Toyota Jidosha Kabushiki Kaisha | Electrode for preventing noise electric wave and method thereof |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6030476A (en) * | 1983-07-27 | 1985-02-16 | Hitachi Ltd | Distributor for internal-combustion engine |
| JPS6030475A (en) * | 1983-07-27 | 1985-02-16 | Hitachi Ltd | Distributor for internal-combustion engine |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5390534A (en) * | 1977-01-18 | 1978-08-09 | Toyota Central Res & Dev Lab Inc | Noisy wave eliminating discharge electrode |
-
1981
- 1981-02-25 JP JP2540881A patent/JPS57140563A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5390534A (en) * | 1977-01-18 | 1978-08-09 | Toyota Central Res & Dev Lab Inc | Noisy wave eliminating discharge electrode |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0635637A1 (en) * | 1993-07-22 | 1995-01-25 | Toyota Jidosha Kabushiki Kaisha | Electrode for preventing noise electric wave and method thereof |
| EP0793016A3 (en) * | 1993-07-22 | 1998-08-19 | Toyota Jidosha Kabushiki Kaisha | Electrode for preventing noise electric wave and method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS57140563A (en) | 1982-08-31 |
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