JPH09260024A - Spark plug with built-in pressure sensor - Google Patents
Spark plug with built-in pressure sensorInfo
- Publication number
- JPH09260024A JPH09260024A JP7074996A JP7074996A JPH09260024A JP H09260024 A JPH09260024 A JP H09260024A JP 7074996 A JP7074996 A JP 7074996A JP 7074996 A JP7074996 A JP 7074996A JP H09260024 A JPH09260024 A JP H09260024A
- Authority
- JP
- Japan
- Prior art keywords
- diaphragm
- spark plug
- metal shell
- pressure
- piezoelectric
- 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.)
- Pending
Links
Landscapes
- Spark Plugs (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】この発明は、エンジンの気筒
内の燃焼圧力を検出するための圧力センサを内蔵したス
パークプラグに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spark plug incorporating a pressure sensor for detecting combustion pressure in a cylinder of an engine.
【０００２】[0002]
【従来の技術】ノッキングの発生を防止するとともにト
ルク変動を一定値以下に抑えるため、気筒内の燃焼圧力
変動を検出する圧力センサを組み込んだ圧力センサ内蔵
スパークプラグが使用され、機関のトルク変動の検出、
ノッキングの検出などが行われている。2. Description of the Related Art In order to prevent the occurrence of knocking and suppress the torque fluctuation to a certain value or less, a spark plug with a built-in pressure sensor incorporating a pressure sensor for detecting the combustion pressure fluctuation in a cylinder is used. detection,
Knocking detection etc. are performed.
【０００３】従来の圧力センサ内蔵スパークプラグは、
圧力センサをスパークプラグの主体金具の径大胴部と、
機関のシリンダーヘッドに設けたスパークプラグ装着用
ネジ穴の周囲のスパークプラグ取付座との間に取り付け
る構成か、または主体金具に圧力導入穴を設け、該圧力
導入穴に臨ませた圧力センサに燃焼ガスの圧力を導く構
成であった。A conventional spark plug with a built-in pressure sensor is
The pressure sensor is connected to the large-diameter body of the metal shell of the spark plug,
The structure is to be installed between the spark plug mounting screw hole provided on the cylinder head of the engine and the spark plug mounting seat, or a pressure introducing hole is provided on the metal shell, and the pressure sensor facing the pressure introducing hole is burned. It was configured to guide the pressure of gas.
【０００４】[0004]
【発明が解決しようとする課題】しかるに、前者におい
ては燃焼圧力以外にバルブの着座ノイズなどエンジンの
種々の振動を検出し易く、後者は、気筒内振動および圧
力の応答遅れがあり、測定誤差が生じ易い欠点がある。
また、かかる欠点を解消するためダイヤフラムを用いる
と、部品形状および主体金具の構造が複雑となり、製造
コストが増大するとともに、スパークプラグの性能を損
なう問題が生じる。In the former case, however, it is easy to detect various engine vibrations such as valve seating noise in addition to the combustion pressure. In the latter case, there are internal cylinder vibrations and pressure response delays, resulting in measurement error. There are drawbacks that are likely to occur.
Further, if a diaphragm is used to solve such a defect, the shape of parts and the structure of the metal shell become complicated, the manufacturing cost increases, and the performance of the spark plug is impaired.
【０００５】この発明の目的は、ノイズの検出および応
答遅れを解消するとともに、主体金具および絶縁体の改
造を最小限にでき、製造コストの増大およびスパークプ
ラグの性能低下を防止できる圧力センサ内蔵スパークプ
ラグの提供にある。An object of the present invention is to eliminate the noise detection and response delay, minimize the modification of the metal shell and the insulator, and prevent the increase of the manufacturing cost and the deterioration of the performance of the spark plug. In the provision of a plug.
【０００６】[0006]
【課題を解決するための手段】この発明の圧力センサ内
蔵スパークプラグは、軸穴を有する絶縁体と、前記軸穴
に貫設した中心電極と、前記絶縁体の先側部分に外嵌め
した筒状の主体金具とを備え、前記主体金具は、先端が
ネジ部、中間が径大の胴部となっているスパークプラグ
と、前記主体金具の先端面から前記ネジ部に形成され、
燃焼室に臨んだ環状開口を有する環状凹所と、該環状凹
所と前記主体金具の外周面とを連結する貫通穴と、前記
環状凹所の奥に配設した圧電セットと、該貫通穴を通じ
て外部に引き出された前記圧電セットのリード線と、前
記環状開口を塞ぐように設けたダイヤフラムと、該ダイ
ヤフラムと前記圧電セットとの間に配した圧力伝達部材
とからなる。A spark plug with a built-in pressure sensor according to the present invention comprises an insulator having a shaft hole, a center electrode penetrating through the shaft hole, and a cylinder externally fitted to a front portion of the insulator. A metal shell, and the metal shell is formed on the threaded portion from the front end surface of the metal shell, and a spark plug having a threaded portion at the tip and a body portion with a large diameter in the middle,
An annular recess having an annular opening facing the combustion chamber, a through hole connecting the annular recess and the outer peripheral surface of the metal shell, a piezoelectric set disposed at the back of the annular recess, and the through hole The lead wire of the piezoelectric set, which is drawn to the outside through the diaphragm, the diaphragm provided so as to close the annular opening, and the pressure transmission member arranged between the diaphragm and the piezoelectric set.
【０００７】[0007]
【発明の作用および効果】この発明では、主体金具の先
端面の内側に配したダイヤフラムにより直接に燃焼室の
圧力変動を受け、これを圧力伝達部材を介して圧電セッ
トに伝達している。このため、ノイズの検出および応答
遅れを解消するとともに、主体金具および絶縁体の改造
を最小限にでき、製造コストの増大およびスパークプラ
グの性能低下を防止できる。According to the present invention, the pressure fluctuation of the combustion chamber is directly received by the diaphragm arranged inside the front end surface of the metallic shell, and this fluctuation is transmitted to the piezoelectric set through the pressure transmission member. Therefore, it is possible to eliminate noise detection and response delay, minimize the modification of the metal shell and the insulator, and prevent an increase in manufacturing cost and a decrease in performance of the spark plug.
【０００８】[0008]
【発明の実施の形態】図１は、この発明の圧電センサ付
スパークプラグを示し、筒状の主体金具１内に、軸穴２
１付き絶縁体２の先側部分を嵌め込んで固定している。
軸穴２１内には中心電極３が貫設されており、絶縁体２
の先端から突き出している中心電極３の先端部３１は発
火部となっており、絶縁体２の後端から突き出している
中心電極３の後端部３２は、点火回路の高電圧コードへ
の接続端子となっている。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a spark plug with a piezoelectric sensor according to the present invention.
The front side portion of the insulator 2 with 1 is fitted and fixed.
A center electrode 3 is provided in the shaft hole 21 so that the insulator 2
The tip 31 of the center electrode 3 protruding from the tip of the center electrode 3 is an ignition part, and the rear end 32 of the center electrode 3 protruding from the rear of the insulator 2 is connected to the high voltage cord of the ignition circuit. It is a terminal.
【０００９】主体金具１は、先端側に外周にエンジンへ
の締結ネジが形成されたネジ部１１を有し、中間に径大
の胴部１２を有し、後側に六角頭部１３を有する。六角
頭部１３の後端には肉薄のかしめ部１４が延設されてお
り、中間胴部１２と六角頭部１３との間は肉薄の圧縮部
１５が設けられている。The metal shell 1 has a threaded portion 11 on the outer periphery on which a fastening screw for an engine is formed, a body portion 12 having a large diameter in the middle, and a hexagonal head 13 on the rear side. . A thin caulking portion 14 is extended at the rear end of the hexagonal head portion 13, and a thin compression portion 15 is provided between the intermediate body portion 12 and the hexagonal head portion 13.
【００１０】ネジ部１１の先端には、内周を内側に突出
して環状接地電極４が形成されており、該接地電極４と
中心電極３の先端部３１の外周との間は火花放電ギャッ
プＧとなっている。接地電極４は、主体金具１の先端部
に溶接した１または複数の略Ｌ字形の接地電極であって
もよい。主体金具１の内腔１０は、胴部１２に傾斜段１
６が設けられ、傾斜段１６の先側１Ａが径小に形成され
るとともに絶縁体２との係合突条１７が周設され、傾斜
段１６の後側１Ｂが径大となっている。An annular ground electrode 4 is formed at the tip of the screw portion 11 so as to project inward from the inner circumference, and a spark discharge gap G is formed between the ground electrode 4 and the outer circumference of the tip 31 of the center electrode 3. Has become. The ground electrode 4 may be one or a plurality of substantially L-shaped ground electrodes welded to the tip of the metal shell 1. The inner cavity 10 of the metallic shell 1 has a slanted step 1 on the body 12.
6 is provided, the front side 1A of the inclined step 16 is formed to have a small diameter, and the engaging protrusion 17 with the insulator 2 is circumferentially provided, and the rear side 1B of the inclined step 16 has a large diameter.
【００１１】ネジ部（Ｍ１４、ピッチ１．２５ｍｍ）１
１は、内径が６．５ｍｍ、肉厚が５〜６ｍｍに形成され
るとともに、ネジ部１１（主体金具１）の先端面１９に
円環状開口５１を有する円環状凹所５が設けられてい
る。円環状凹所５の奥部と、胴部１２の肩面１２１の表
面との間は、主体金具１の壁内に形成した貫通穴５２に
より連通している。円環状凹所５は、内径が８〜９ｍ
ｍ、深さが８〜１２ｍｍの範囲内で形成されており、ス
パークプラグとしての耐久性、装着製および構造強度の
維持が図られている。Screw part (M14, pitch 1.25 mm) 1
1 has an inner diameter of 6.5 mm and a wall thickness of 5 to 6 mm, and is provided with an annular recess 5 having an annular opening 51 on the tip surface 19 of the screw portion 11 (metal shell 1). . The inner portion of the annular recess 5 and the surface of the shoulder surface 121 of the body 12 are communicated with each other by a through hole 52 formed in the wall of the metal shell 1. The annular recess 5 has an inner diameter of 8 to 9 m.
m, and the depth is formed within the range of 8 to 12 mm, and durability as a spark plug, mounting and maintenance of structural strength are achieved.
【００１２】絶縁体２は、先側に主体金具１のネジ部１
１に収容される脚長部２２、中間に胴部１２内に収容さ
れ、後端１Ｂに嵌合する径大のつば部２３を有する。後
側は、大部分が主体金具１の後端から突き出したプラグ
キャップ接続部２４となっている。脚長部２２の中間部
には、主体金具１の内腔１０に設けられた係合突条１７
にパツキン９を介して係合する係合段２５が形成され、
プラグキャップ接続部２４の後部には、コルゲーション
２６が設けられている。The insulator 2 has a screw portion 1 of the metal shell 1 on the front side.
1 has a long leg portion 22 accommodated therein, and a middle portion has a large-diameter collar portion 23 accommodated in the body portion 12 and fitted to the rear end 1B. Most of the rear side is a plug cap connecting portion 24 protruding from the rear end of the metal shell 1. An engaging projection 17 provided in the inner cavity 10 of the metal shell 1 is provided at an intermediate portion of the leg long portion 22.
Is formed with an engagement step 25 that engages via the packing 9.
A corrugation 26 is provided at the rear of the plug cap connecting portion 24.
【００１３】円環状凹所５の円環状開口５１は、円環状
のダイヤフラム６によって塞がれており、円環状凹所５
の奥部には、図２に示す圧電セット７が嵌め込まれてい
る。ダイヤフラム６と圧電セット７との間には、円筒状
の圧力伝達部材８が嵌め込まれている。ダイヤフラム６
は、ニッケル合金製で、外径が１２ｍｍ、内径６ｍｍ、
厚さ０．１５〜０．３０ｍｍに設定されている。The ring-shaped opening 51 of the ring-shaped recess 5 is closed by the ring-shaped diaphragm 6, and the ring-shaped recess 5 is formed.
The piezoelectric set 7 shown in FIG. A cylindrical pressure transmission member 8 is fitted between the diaphragm 6 and the piezoelectric set 7. Diaphragm 6
Is made of nickel alloy and has an outer diameter of 12 mm, an inner diameter of 6 mm,
The thickness is set to 0.15 to 0.30 mm.
【００１４】圧電セット７は、いずれも環状の、絶縁板
７１、電極板７２、圧電素子７３および受圧板としての
板パッキン７４を積層してなる。電極板７２には、絶縁
被覆付きリード線７５が接続されており、絶縁板７１に
設けた切り欠き７６を通じて貫通穴５２から外部に取り
出されている。リード線７５が挿通された貫通穴５２
は、耐熱接着剤でシールされていることが望ましい。The piezoelectric set 7 is formed by laminating an insulating plate 71, an electrode plate 72, a piezoelectric element 73, and a plate packing 74 as a pressure receiving plate, all of which are annular. A lead wire 75 with an insulation coating is connected to the electrode plate 72, and is taken out to the outside from the through hole 52 through a notch 76 provided in the insulation plate 71. Through hole 52 through which the lead wire 75 is inserted
Is preferably sealed with a heat resistant adhesive.
【００１５】ダイヤフラム６は、この実施例では、内周
６２が圧力伝達部材８の先端に設けられた肉薄の括れ部
８１に連続して一体成形されている。ダイヤフラム６
は、外周６１および内周６２が、主体金具１の円環状凹
所５の先端面１９にシーム溶接されている。ダイヤフラ
ム６の外周６１および内周６２をシーム溶接するのは、
接合部の機密性を保つとともに、ダイヤフラム６の材質
の変化を最小限に保ちながら所定位置に保持するためで
ある。In this embodiment, the diaphragm 6 has an inner circumference 62 integrally formed continuously with a thin constricted portion 81 provided at the tip of the pressure transmitting member 8. Diaphragm 6
The outer circumference 61 and the inner circumference 62 are seam-welded to the tip surface 19 of the annular recess 5 of the metal shell 1. Seam welding the outer periphery 61 and the inner periphery 62 of the diaphragm 6 is
This is because the airtightness of the joint is maintained and the diaphragm 6 is held at a predetermined position while keeping the change in the material of the diaphragm 6 to a minimum.
【００１６】圧力伝達部材８は、先端に厚さ０．３〜
０．８ｍｍ、長さ１．５ｍｍの括れ部８１が設けられ、
外径８．５〜９ｍｍ、内径８ｍｍ、長さ６〜７ｍｍの筒
体からなり、後端に設けられ板パッキン７４に当接する
後端鍔部８３が設けられている。The pressure transmitting member 8 has a thickness of 0.3 to
A constricted portion 81 having a length of 0.8 mm and a length of 1.5 mm is provided,
A tubular body having an outer diameter of 8.5 to 9 mm, an inner diameter of 8 mm, and a length of 6 to 7 mm is provided with a rear end flange portion 83 provided at the rear end and abutting the plate packing 74.
【００１７】このスパークプラグは、エンジンに装着さ
れると燃焼室の圧力変動は、ダイヤフラム６により加わ
り、圧力伝達部材８を介して圧電セット７に伝達され
る。すなわち、燃焼室の圧力は、ダイヤフラム６は外周
６１および内周６２が主体金具１の先端面１９に溶接さ
れているため、内周６２に連結した圧力伝達部材８に加
わり、後端鍔部８３が板パッキン７４を加圧する。この
際、括れ部８１は、圧力伝達部材８の微動を円滑に行わ
せる作用を有する。When this spark plug is mounted on the engine, pressure fluctuations in the combustion chamber are added by the diaphragm 6 and transmitted to the piezoelectric set 7 via the pressure transmission member 8. That is, since the outer circumference 61 and the inner circumference 62 of the diaphragm 6 are welded to the front end surface 19 of the metal shell 1, the pressure of the combustion chamber is applied to the pressure transmission member 8 connected to the inner circumference 62, and the rear end collar portion 83. Pressurizes the plate packing 74. At this time, the constricted portion 81 has a function of smoothly performing fine movement of the pressure transmission member 8.
【００１８】このため、燃焼室の圧力変動を直接かつ時
間に遅れずに検出でき、ノイズの検出および応答遅れを
解消できる。また、主体金具および絶縁体の改造を最小
限にでき、製造コストの増大およびスパークプラグの性
能低下を防止できる。Therefore, pressure fluctuations in the combustion chamber can be detected directly and without delay, and noise detection and response delay can be eliminated. Further, it is possible to minimize the modification of the metal shell and the insulator, and it is possible to prevent the manufacturing cost from increasing and the performance of the spark plug from decreasing.
【図１】圧力センサ内蔵スパークプラグの断面図であ
る。FIG. 1 is a sectional view of a spark plug with a built-in pressure sensor.
【図２】圧力センサの斜視図である。FIG. 2 is a perspective view of a pressure sensor.
１ 主体金具 ２ 絶縁体 ３ 中心電極 ４ 接地電極 ５ 円環状凹所 ６ ダイヤフラム ７ 圧電セット ８ 圧力伝達部材 １１ ネジ部 １２ 胴部 １９ 先端面 ２１ 軸穴 ５１ 円環状開口 ５２ 貫通穴 ６１ 外周 ６２ 内周 ７５ リード線 ８１ 肉薄の括れ部 DESCRIPTION OF SYMBOLS 1 Metal shell 2 Insulator 3 Center electrode 4 Ground electrode 5 Circular recess 6 Diaphragm 7 Piezoelectric set 8 Pressure transmission member 11 Screw part 12 Body part 19 Tip surface 21 Shaft hole 51 Circular opening 52 Through hole 61 Outer circumference 62 Inner circumference 75 Lead wire 81 Thin constricted part
Claims (4)
した中心電極と、前記絶縁体の先側部分に外嵌めした筒
状の主体金具とを備え、前記主体金具は、先端がネジ
部、中間が径大の胴部となっているスパークプラグと、
前記主体金具の先端面から前記ネジ部に形成され、燃焼
室に臨んだ環状開口を有する環状凹所と、該環状凹所と
前記主体金具の外周面とを連結する貫通穴と、前記環状
凹所の奥に配設した圧電セットと、該貫通穴を通じて外
部に引き出された前記圧電セットのリード線と、前記環
状開口を塞ぐように設けたダイヤフラムと、該ダイヤフ
ラムと前記圧電セットとの間に配した圧力伝達部材とか
らなる圧力センサ内蔵スパークプラグ。1. An insulator having a shaft hole, a center electrode penetrating the shaft hole, and a tubular metal shell externally fitted to a front side portion of the insulator, the metal shell having a tip end. Is a spark plug, and the middle is a large diameter trunk,
An annular recess formed in the threaded portion from the front end surface of the metal shell and having an annular opening facing the combustion chamber, a through hole connecting the annular recess and the outer peripheral surface of the metal shell, and the annular recess. A piezoelectric set disposed at the back of the place, a lead wire of the piezoelectric set drawn to the outside through the through hole, a diaphragm provided so as to close the annular opening, and between the diaphragm and the piezoelectric set. A spark plug with a built-in pressure sensor that consists of a pressure transmitting member.
は、外周および内周が前記主体金具の先端面にシーム溶
接されていることを特徴とする圧力センサ内蔵スパーク
プラグ。2. The spark plug with a built-in pressure sensor according to claim 1, wherein an outer circumference and an inner circumference of the diaphragm are seam-welded to a front end surface of the metal shell.
達部材は円筒状を呈し、前記ダイヤフラムと一体成形さ
れたことを特徴とする圧力センサ内蔵スパークプラグ。3. The spark plug with a built-in pressure sensor according to claim 1, wherein the pressure transmission member has a cylindrical shape and is integrally formed with the diaphragm.
ダイヤフラムへの連結部は、肉薄の括れ部となっている
ことを特徴とする圧力センサ内蔵スパークプラグ。4. The spark plug with a built-in pressure sensor according to claim 3, wherein the connecting portion of the pressure transmitting member to the diaphragm is a thin constricted portion.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7074996A JPH09260024A (en) | 1996-03-26 | 1996-03-26 | Spark plug with built-in pressure sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7074996A JPH09260024A (en) | 1996-03-26 | 1996-03-26 | Spark plug with built-in pressure sensor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH09260024A true JPH09260024A (en) | 1997-10-03 |
Family
ID=13440480
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7074996A Pending JPH09260024A (en) | 1996-03-26 | 1996-03-26 | Spark plug with built-in pressure sensor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH09260024A (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1999064834A1 (en) * | 1998-06-12 | 1999-12-16 | Federal-Mogul Corporation | Spark plug with pressure sensor |
| WO2002008714A1 (en) * | 2000-07-21 | 2002-01-31 | Robert Bosch Gmbh | Spark plug for receiving a pressure sensor and corresponding spark plug connector |
| US6675785B2 (en) * | 2002-04-01 | 2004-01-13 | Denso Corporation | Ignition device for an internal combustion engine |
| JP2008004266A (en) * | 2006-04-04 | 2008-01-10 | Ngk Spark Plug Co Ltd | Spark plug |
| CH699078A1 (en) * | 2008-07-02 | 2010-01-15 | Kistler Holding Ag | Spark plug in basic structure with pressure sensor. |
| US8237343B2 (en) | 2005-08-22 | 2012-08-07 | Ngk Spark Plug Co., Ltd. | Spark plug having a metal fitting portion for holding an insulator at a portion opposite a tip end |
| CN103956654A (en) * | 2014-05-09 | 2014-07-30 | 张蝶儿 | Sparking plug |
-
1996
- 1996-03-26 JP JP7074996A patent/JPH09260024A/en active Pending
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1999064834A1 (en) * | 1998-06-12 | 1999-12-16 | Federal-Mogul Corporation | Spark plug with pressure sensor |
| WO2002008714A1 (en) * | 2000-07-21 | 2002-01-31 | Robert Bosch Gmbh | Spark plug for receiving a pressure sensor and corresponding spark plug connector |
| DE10035536A1 (en) * | 2000-07-21 | 2002-02-07 | Bosch Gmbh Robert | Spark plug to hold a pressure sensor and associated spark plug connector |
| DE10035536C2 (en) * | 2000-07-21 | 2003-06-05 | Bosch Gmbh Robert | Spark plug to hold a pressure sensor and associated spark plug connector |
| US6952948B2 (en) | 2000-07-21 | 2005-10-11 | Robert Bosch Gmbh | Spark plug for receiving a pressure sensor and corresponding spark plug connector |
| US6675785B2 (en) * | 2002-04-01 | 2004-01-13 | Denso Corporation | Ignition device for an internal combustion engine |
| US8237343B2 (en) | 2005-08-22 | 2012-08-07 | Ngk Spark Plug Co., Ltd. | Spark plug having a metal fitting portion for holding an insulator at a portion opposite a tip end |
| JP2008004266A (en) * | 2006-04-04 | 2008-01-10 | Ngk Spark Plug Co Ltd | Spark plug |
| CH699078A1 (en) * | 2008-07-02 | 2010-01-15 | Kistler Holding Ag | Spark plug in basic structure with pressure sensor. |
| CN103956654A (en) * | 2014-05-09 | 2014-07-30 | 张蝶儿 | Sparking plug |
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