JP6460590B2

JP6460590B2 - Combustion pressure sensor

Info

Publication number: JP6460590B2
Application number: JP2014141893A
Authority: JP
Inventors: 篤史本田; 翔一竹本; 昭彦亀島
Original assignee: Denso Corp
Current assignee: Denso Corp
Priority date: 2014-07-10
Filing date: 2014-07-10
Publication date: 2019-01-30
Anticipated expiration: 2034-07-10
Also published as: JP2016017490A

Description

本発明は、内燃機関の燃焼室内における燃焼圧を検出するための燃焼圧センサに関する。 The present invention relates to a combustion pressure sensor for detecting a combustion pressure in a combustion chamber of an internal combustion engine.

車両等の内燃機関に取付けられ、内燃機関の燃焼室内における燃焼圧を検出するための燃焼圧センサとして、例えば特許文献１に記載された燃焼圧センサがある。特許文献１に記載の燃焼圧センサでは、燃焼室を構成するシリンダヘッドに設けられた貫通孔を介して伝達部材の先端に形成された受圧部が燃焼室内に露出しており、伝達部材の後端には圧電素子からなる検出部が接続されている。受圧部が燃焼室の燃焼圧を受けると、伝達部材に伝達されて伝達部材に負荷される荷重が変化する。そして、伝達部材に生じた荷重の変化を検出部が検知することにより燃焼圧を検出する。 As a combustion pressure sensor that is attached to an internal combustion engine such as a vehicle and detects a combustion pressure in a combustion chamber of the internal combustion engine, there is a combustion pressure sensor described in Patent Document 1, for example. In the combustion pressure sensor described in Patent Document 1, a pressure receiving portion formed at the tip of the transmission member is exposed in the combustion chamber through a through hole provided in a cylinder head constituting the combustion chamber, and the rear of the transmission member A detection unit made of a piezoelectric element is connected to the end. When the pressure receiving portion receives the combustion pressure in the combustion chamber, the load transmitted to the transmission member and applied to the transmission member changes. And a combustion pressure is detected when a detection part detects the change of the load which arose to the transmission member.

特開２００９−１４４７０２号公報JP 2009-144702 A

しかしながら、特許文献１に開示の構成では、伝達部材が燃焼室内に露出しているため、燃焼室内の燃料や潤滑油の残渣に由来するデポジット等が伝達部材とシリンダヘッドとの間に堆積する場合がある。そして、デポジット等が伝達部材に堆積すると伝達部材における燃焼圧の伝達精度が低下して燃焼圧の検出精度が低下する。そして、内燃機関の使用期間が長くなるほど、上記デポジットが堆積しやすくなるため、経時的に燃焼圧の検出精度が低下するという問題がある。 However, in the configuration disclosed in Patent Document 1, since the transmission member is exposed in the combustion chamber, deposits or the like derived from fuel or lubricant residue in the combustion chamber accumulate between the transmission member and the cylinder head. There is. When deposits or the like are accumulated on the transmission member, the transmission accuracy of the combustion pressure in the transmission member is lowered and the detection accuracy of the combustion pressure is lowered. And, as the period of use of the internal combustion engine becomes longer, the deposit tends to accumulate, and there is a problem that the detection accuracy of the combustion pressure decreases with time.

本発明は、かかる背景に鑑みてなされたもので、経時的に燃焼圧の検出精度が低下することが防止される燃焼圧センサを提供しようとするものである。 The present invention has been made in view of such a background, and an object of the present invention is to provide a combustion pressure sensor that prevents the detection accuracy of combustion pressure from decreasing with time.

本発明の一態様は、内燃機関の燃焼室内における燃焼圧を検出するための燃焼圧センサであって、
上記燃焼室を構成するシリンダヘッドの外側に開口するように該シリンダヘッドに形成された有底孔の底部に当接して上記燃焼室内における燃焼圧を受けるように構成された受圧部と、
該受圧部が受けた燃焼圧を検出する検出部と、
上記受圧部が受けた燃焼圧を上記検出部に伝達する伝達部と、
上記シリンダヘッドに固定可能な固定部と、
上記検出部及び上記伝達部を保持するハウジングと、
を備え、
上記伝達部は、軸方向に延びる棒状部材からなり、
上記検出部は、圧電素子を含む荷重検出器からなり、
上記検出部における軸方向の先端側に位置する下面は、上記伝達部の軸方向の後端に軸方向に当接しており、
上記検出部における軸方向の後端側に位置する上面は、上記ハウジングに固定された固定部材に軸方向に当接していることを特徴とする燃焼圧センサにある。 One aspect of the present invention is a combustion pressure sensor for detecting a combustion pressure in a combustion chamber of an internal combustion engine,
A pressure receiving portion configured to contact a bottom portion of a bottomed hole formed in the cylinder head so as to open to the outside of the cylinder head constituting the combustion chamber and to receive a combustion pressure in the combustion chamber;
A detection unit for detecting the combustion pressure received by the pressure receiving unit;
A transmission unit that transmits the combustion pressure received by the pressure receiving unit to the detection unit;
A fixing part that can be fixed to the cylinder head;
A housing for holding the detection unit and the transmission unit;
Equipped with a,
The transmission part is composed of a rod-shaped member extending in the axial direction,
The detection unit includes a load detector including a piezoelectric element,
The lower surface located on the front end side in the axial direction of the detection unit is in axial contact with the rear end of the transmission unit in the axial direction,
Upper surface located on the rear end side in the axial direction of the detection unit is in the combustion pressure sensor characterized that you have contact with the axially stationary member fixed to the housing.

上記燃焼圧センサにおいては、受圧部はシリンダヘッドの外側に開口する有底孔の底部に当接しており、当該底部から燃焼圧を受けるように構成されている。すなわち、燃焼室内で燃焼圧の変化に伴ってシリンダヘッドに弾性変形（歪み）が生じると有底孔の底部にも弾性変形（歪み）が生じる。当該底部に当接する受圧部はこれに伴って変位することとなる。そして、受圧部の変位が伝達部を介して検出部に伝達されて燃焼圧が検出されることとなる。そのため、受圧部が燃焼室内に露出することがないことから、受圧部とシリンダヘッドとの間に燃焼室内の燃料や潤滑油の残渣に由来するデポジット等が堆積することがない。その結果、経時的に燃焼圧の検出精度が低下することが防止される。また、上記燃焼圧センサにおいては、シリンダヘッドの外側に開口するよう形成された有底孔の底部の弾性変形（歪み）を検知して燃焼圧を検出している。そのため、上記燃焼圧センサは、有底孔が形成されていないシリンダヘッドの外表面の弾性変形を検知する場合に比べて、当該弾性変形に基づく受圧部の変位量を確保しやすいことから検出精度に優れる。 In the combustion pressure sensor, the pressure receiving portion is in contact with the bottom portion of the bottomed hole that opens to the outside of the cylinder head, and is configured to receive the combustion pressure from the bottom portion. That is, when an elastic deformation (strain) occurs in the cylinder head as the combustion pressure changes in the combustion chamber, an elastic deformation (strain) also occurs at the bottom of the bottomed hole. The pressure receiving portion that comes into contact with the bottom portion is displaced accordingly. Then, the displacement of the pressure receiving part is transmitted to the detection part via the transmission part, and the combustion pressure is detected. For this reason, since the pressure receiving portion is not exposed in the combustion chamber, deposits or the like derived from fuel or lubricant residue in the combustion chamber are not deposited between the pressure receiving portion and the cylinder head. As a result, the detection accuracy of the combustion pressure is prevented from decreasing with time. Further, in the combustion pressure sensor, the combustion pressure is detected by detecting the elastic deformation (distortion) of the bottom of the bottomed hole formed to open to the outside of the cylinder head. For this reason, the combustion pressure sensor can easily detect the displacement of the pressure receiving portion based on the elastic deformation as compared with the case of detecting the elastic deformation of the outer surface of the cylinder head in which the bottomed hole is not formed. Excellent.

以上のごとく、本発明によれば、経時的に燃焼圧の検出精度が低下することが防止される燃焼圧センサを提供することができる。 As described above, according to the present invention, it is possible to provide a combustion pressure sensor that prevents the detection accuracy of the combustion pressure from decreasing with time.

実施例１における、燃焼圧センサの断面図。2 is a cross-sectional view of a combustion pressure sensor in Embodiment 1. FIG. 実施例２における、燃焼圧センサの断面図。Sectional drawing of the combustion pressure sensor in Example 2. FIG. 実施例３における、燃焼圧センサの断面図。Sectional drawing of the combustion pressure sensor in Example 3. FIG.

本発明の燃焼圧センサは、自動車等の内燃機関に使用することができる。 The combustion pressure sensor of the present invention can be used for an internal combustion engine such as an automobile.

（実施例１）
本例の実施例に係る燃焼圧センサにつき、図１を用いて説明する。
本例の燃焼圧センサ１は、図１に示すように、内燃機関１００の燃焼室１０１内における燃焼圧を検出するためのものである。燃焼圧センサ１は、受圧部１０、検出部２０、伝達部３０、固定部４０を備える。 Example 1
A combustion pressure sensor according to this embodiment will be described with reference to FIG.
The combustion pressure sensor 1 of this example is for detecting the combustion pressure in the combustion chamber 101 of the internal combustion engine 100 as shown in FIG. The combustion pressure sensor 1 includes a pressure receiving unit 10, a detection unit 20, a transmission unit 30, and a fixing unit 40.

受圧部１０は、燃焼室１０１を構成するシリンダヘッド１０２の外側に開口するようにシリンダヘッド１０２に形成された有底孔１０３の底部１０４に当接して燃焼室１０１内における燃焼圧を受けるように構成されている。
検出部２０は、受圧部１０が受けた燃焼圧を検出するものである。
伝達部３０は、受圧部１０が受けた燃焼圧を検出部２０に伝達するためのものである。
そして、固定部４０は、シリンダヘッド１０２に固定可能になっている。 The pressure receiving unit 10 is in contact with the bottom 104 of the bottomed hole 103 formed in the cylinder head 102 so as to open to the outside of the cylinder head 102 constituting the combustion chamber 101 so as to receive the combustion pressure in the combustion chamber 101. It is configured.
The detector 20 detects the combustion pressure received by the pressure receiver 10.
The transmission unit 30 is for transmitting the combustion pressure received by the pressure receiving unit 10 to the detection unit 20.
The fixing unit 40 can be fixed to the cylinder head 102.

以下、本例の燃焼圧センサ１について、詳述する。
図１に示すように、燃焼圧センサ１において、伝達部３０は棒状部材３０ａからなる。伝達部３０の軸方向をＹとし、先端３１側の方向をＹ１方向、後端３２側の方向をＹ２方向とする。伝達部３０の先端３１はその角部が面取りされている。伝達部３０の後端３２は拡径されて鍔状を成している。伝達部３０は、軸方向Ｙに変位可能なように、ハウジング６０内に保持されている。伝達部３０の後端３２には、検出部２０が接続されている。 Hereinafter, the combustion pressure sensor 1 of this example will be described in detail.
As shown in FIG. 1, in the combustion pressure sensor 1, the transmission part 30 consists of the rod-shaped member 30a. The axial direction of the transmission part 30 is Y, the direction on the tip 31 side is the Y1 direction, and the direction on the rear end 32 side is the Y2 direction. The tip 31 of the transmission part 30 has a chamfered corner. The rear end 32 of the transmission part 30 is expanded in diameter to form a bowl shape. The transmission unit 30 is held in the housing 60 so as to be displaceable in the axial direction Y. The detection unit 20 is connected to the rear end 32 of the transmission unit 30.

伝達部３０の後端３２に接続された検出部２０は、圧電素子を備える荷重検出器２０ａからなる。図１に示すように、検出部２０のＹ２方向に位置する下面２１は、伝達部３０の後端３２に当接している。検出部２０のＹ１方向に位置する上面２２は、ハウジング６０内に固定された固定部材５０に当接している。検出部２０は燃焼圧を検出して出力端子２３を介して検出信号を発する。出力端子２３は、固定部材５０のＹ１方向に配設されてハウジング６０内に保持された回路部７０に接続されている。 The detection unit 20 connected to the rear end 32 of the transmission unit 30 includes a load detector 20a including a piezoelectric element. As illustrated in FIG. 1, the lower surface 21 of the detection unit 20 located in the Y2 direction is in contact with the rear end 32 of the transmission unit 30. An upper surface 22 located in the Y1 direction of the detection unit 20 is in contact with a fixing member 50 fixed in the housing 60. The detection unit 20 detects the combustion pressure and issues a detection signal via the output terminal 23. The output terminal 23 is connected to the circuit unit 70 that is disposed in the Y1 direction of the fixing member 50 and is held in the housing 60.

検出部２０及び伝達部３０はハウジング６０内に保持されている。ハウジング６０は、有底の円筒状に形成されている。ハウジング６０は弾性変形可能な材料で形成されている。ハウジング６０のＹ１方向の端部は伝達部３０の先端３１を覆う先端被覆部６１を形成している。そして、先端被覆部６１の内側底面６１ａに伝達部３０の先端３１が当接している。先端被覆部６１は有底孔１０３の底部１０４に当接して受圧部１０を形成している。 The detection unit 20 and the transmission unit 30 are held in the housing 60. The housing 60 is formed in a bottomed cylindrical shape. The housing 60 is made of an elastically deformable material. An end portion in the Y1 direction of the housing 60 forms a tip covering portion 61 that covers the tip 31 of the transmission portion 30. And the front-end | tip 31 of the transmission part 30 is in contact with the inner bottom face 61a of the front-end | tip covering part 61. FIG. The tip covering portion 61 is in contact with the bottom portion 104 of the bottomed hole 103 to form the pressure receiving portion 10.

ハウジング６０内に保持された検出部２０のＹ２方向側には、固定部材５０が設けられている。固定部材５０は略円盤状を成しており、ハウジング６０の内周面に固定されている。固定部材５０は検出部２０の上面２２に当接している。上述の如く、検出部２０の下面２１は伝達部３０の後端３２が検出部２０に当接している。これにより、検出部２０は、固定部材５０によってＹ２方向への変位が規制されている。そして、検出部２０は伝達部３０の後端３２と固定部材５０とによって挟まれて、伝達部３０からの軸方向Ｙの荷重が検出部２０に伝達されるように構成されている。なお、ハウジング６０のＹ２方向端部は開口しており、回路部７０の信号端子５１を保持するコネクタ８０が取り付けられている。コネクタ８０は図示しないハーネスを介してＥＣＵに接続されている。 A fixing member 50 is provided on the Y2 direction side of the detection unit 20 held in the housing 60. The fixing member 50 has a substantially disk shape and is fixed to the inner peripheral surface of the housing 60. The fixing member 50 is in contact with the upper surface 22 of the detection unit 20. As described above, the rear surface 32 of the transmission unit 30 is in contact with the detection unit 20 on the lower surface 21 of the detection unit 20. Thus, the displacement of the detection unit 20 in the Y2 direction is restricted by the fixing member 50. The detection unit 20 is sandwiched between the rear end 32 of the transmission unit 30 and the fixing member 50 so that the load in the axial direction Y from the transmission unit 30 is transmitted to the detection unit 20. Note that the end of the housing 60 in the Y2 direction is open, and a connector 80 that holds the signal terminal 51 of the circuit unit 70 is attached. The connector 80 is connected to the ECU via a harness (not shown).

ハウジング６０の外周部には、シリンダヘッド１０２に固定される固定部４０が備えられている。固定部４０は、ハウジング６０の軸方向Ｙの略中央に設けられている。固定部４０にはらせん状の溝が形成されている。一方、シリンダヘッド１０２に形成された有底孔１０３の内壁面において開口部１０５側には、らせん状の溝からなる被固定部１０６が形成されている。そして、固定部４０は被固定部１０６に螺合するように構成されている。さらに、ハウジング６０の先端被覆部６１の外側面６１ｂは有底孔１０３の底部１０４に当接している。底部１０４はすり鉢状に形成されており、外側面６１ｂが確実に底部１０４に当接するように構成されている。そして、先端被覆部６１は、燃焼圧による有底孔１０３の底部１０４の弾性変形（歪み）に追従して弾性変形可能となっている。そして、当該弾性変形に基づいて、伝達部３０が軸方向Ｙに変位可能となっている。 A fixed portion 40 that is fixed to the cylinder head 102 is provided on the outer peripheral portion of the housing 60. The fixed portion 40 is provided at the approximate center in the axial direction Y of the housing 60. A spiral groove is formed in the fixed portion 40. On the other hand, on the inner wall surface of the bottomed hole 103 formed in the cylinder head 102, a fixed portion 106 formed of a spiral groove is formed on the opening 105 side. The fixing portion 40 is configured to be screwed to the fixed portion 106. Further, the outer side surface 61 b of the tip covering portion 61 of the housing 60 is in contact with the bottom portion 104 of the bottomed hole 103. The bottom portion 104 is formed in a mortar shape, and is configured so that the outer side surface 61b is in contact with the bottom portion 104 with certainty. And the front-end | tip coating | coated part 61 can be elastically deformed following the elastic deformation (distortion) of the bottom part 104 of the bottomed hole 103 by a combustion pressure. And the transmission part 30 can be displaced to the axial direction Y based on the said elastic deformation.

燃焼圧センサ１の取り付け態様は以下の通りである。まず、燃焼圧センサ１の先端、すなわち、受圧部１０から有底孔１０３に挿入される。そして、受圧部１０が底部１０４に当接するまで、固定部４０を被固定部１０６に螺合させて燃焼圧センサ１を螺入する。これにより、燃焼圧センサ１は有底孔１０３の所定位置に配設されてシリンダヘッド１０２に取り付けられることとなる。 The attachment mode of the combustion pressure sensor 1 is as follows. First, the tip of the combustion pressure sensor 1, that is, the pressure receiving part 10 is inserted into the bottomed hole 103. Then, until the pressure receiving part 10 comes into contact with the bottom part 104, the fixing part 40 is screwed into the fixed part 106 and the combustion pressure sensor 1 is screwed. As a result, the combustion pressure sensor 1 is disposed at a predetermined position of the bottomed hole 103 and attached to the cylinder head 102.

有底孔１０３は、底部１０４の反対側の面１０４ａが燃焼室１０１内に面することとなる位置に形成されている。有底孔１０３の深さ（すなわち、シリンダヘッド１０２の外側表面１０２ａと底部１０４との軸方向Ｙにおける距離）は、シリンダヘッド１０２の厚さ、燃焼室１０１の形状、有底孔１０３の形成容易性などを考慮して適宜決定することができる。固定部４０のＹ１側端部（下端）４０ａから底部１０４までの距離ｈは、伝達部３０の変位量を確保できる大きさであればよい。有底孔１０３の内径は、固定部４０よりも先端側（Ｙ１方向）におけるハウジング６０の外径よりも若干大きくなっている。 The bottomed hole 103 is formed at a position where the surface 104 a opposite to the bottom 104 faces the inside of the combustion chamber 101. The depth of the bottomed hole 103 (that is, the distance in the axial direction Y between the outer surface 102a of the cylinder head 102 and the bottom 104) is the thickness of the cylinder head 102, the shape of the combustion chamber 101, and the ease of forming the bottomed hole 103. It can be appropriately determined in consideration of the characteristics. The distance h from the Y1-side end (lower end) 40a of the fixed portion 40 to the bottom portion 104 may be a size that can secure the amount of displacement of the transmitting portion 30. The inner diameter of the bottomed hole 103 is slightly larger than the outer diameter of the housing 60 on the distal end side (Y1 direction) from the fixed portion 40.

本例の燃焼圧センサ１による燃焼圧の検出態様は以下の通りである。
まず、燃焼室１０１内の燃焼圧が変化すると、シリンダヘッド１０２に弾性変形（歪み）が生じる。これに伴って、有底孔１０３の底部１０４にも弾性変形（歪み）が生じる。そして、受圧部１０は底部１０４に当接しているため、底部１０４の弾性変形に基づいて、受圧部１０が変位することとなる。これにより、受圧部１０に当接している伝達部３０が軸方向Ｙに変位し、検出部２０に負荷されている荷重が変化する。検出部２０は、当該荷重の変化を検知し、検知した荷重の変化量に基づいて燃焼圧を検出する。 The detection mode of the combustion pressure by the combustion pressure sensor 1 of this example is as follows.
First, when the combustion pressure in the combustion chamber 101 changes, the cylinder head 102 undergoes elastic deformation (distortion). Along with this, elastic deformation (strain) also occurs at the bottom 104 of the bottomed hole 103. Since the pressure receiving portion 10 is in contact with the bottom portion 104, the pressure receiving portion 10 is displaced based on the elastic deformation of the bottom portion 104. Thereby, the transmission part 30 in contact with the pressure receiving part 10 is displaced in the axial direction Y, and the load applied to the detection part 20 changes. The detection unit 20 detects the change in the load, and detects the combustion pressure based on the detected change in the load.

次に、本例の燃焼圧センサ１における作用効果について、詳述する。
燃焼圧センサ１によれば、受圧部１０はシリンダヘッド１０２の外側に開口する有底孔１０３の底部１０４に当接しており、底部１０４から燃焼圧を受けるように構成されている。そのため、受圧部１０が燃焼室１０１内に露出することがない。これにより、受圧部１０とシリンダヘッド１０２との間に燃焼室１０１内の燃料や潤滑油の残渣に由来するデポジット等が堆積することがない。その結果、燃焼圧センサ１において、経時的に燃焼圧の検出精度が低下することが防止される。また、燃焼圧センサ１では、有底孔１０３の底部１０４の弾性変形（歪み）を検知して燃焼圧を検出しているため、有底孔１０３が形成されていないシリンダヘッドの外表面の弾性変形を検知する場合に比べて、受圧部１０の変位量を確保しやすいことから検出精度に優れる。 Next, the effect of the combustion pressure sensor 1 of this example will be described in detail.
According to the combustion pressure sensor 1, the pressure receiving portion 10 is in contact with the bottom portion 104 of the bottomed hole 103 that opens to the outside of the cylinder head 102, and is configured to receive the combustion pressure from the bottom portion 104. Therefore, the pressure receiving unit 10 is not exposed in the combustion chamber 101. As a result, deposits or the like derived from fuel or lubricant residue in the combustion chamber 101 do not accumulate between the pressure receiving unit 10 and the cylinder head 102. As a result, in the combustion pressure sensor 1, the detection accuracy of the combustion pressure is prevented from decreasing with time. Further, since the combustion pressure sensor 1 detects the combustion pressure by detecting the elastic deformation (distortion) of the bottom 104 of the bottomed hole 103, the elasticity of the outer surface of the cylinder head in which the bottomed hole 103 is not formed. Compared with the case where deformation is detected, the amount of displacement of the pressure receiving unit 10 can be easily secured, so that the detection accuracy is excellent.

また、本例では、燃焼圧センサ１は、検出部２０を形成する荷重検出器２０ａと、伝達部３０を形成する棒状部材３０ａと、荷重検出器２０ａと棒状部材３０ａとを保持するハウジング６０とを備える。そして、受圧部１０はハウジング６０に形成された伝達部３０（棒状部材３０ａ）の先端３１を覆う先端被覆部６１からなり、伝達部３０（棒状部材３０ａ）の先端３１は受圧部１０（先端被覆部６１）の内側面６１ａに当接しており、伝達部３０（棒状部材３０ａ）の後端３２には検出部２０（荷重検出器２０ａ）が接続されている。荷重検出器２０ａは燃焼圧により受圧部１０を介して伝達部３０（棒状部材３０ａ）に生じた荷重の変化を検知して燃焼圧を検出するように構成されている。これにより、伝達部３０（棒状部材３０ａ）全体がハウジング６０に内包されるため、燃焼圧センサ１の取扱いが容易となり、組み付け作業性が向上する。 Further, in this example, the combustion pressure sensor 1 includes a load detector 20a that forms the detection unit 20, a rod-shaped member 30a that forms the transmission unit 30, and a housing 60 that holds the load detector 20a and the rod-shaped member 30a. Is provided. The pressure receiving part 10 is composed of a tip covering part 61 that covers the tip 31 of the transmission part 30 (bar-shaped member 30a) formed in the housing 60. The tip 31 of the transmission part 30 (bar-shaped member 30a) is The detecting portion 20 (load detector 20a) is connected to the rear end 32 of the transmitting portion 30 (bar-shaped member 30a). The load detector 20a is configured to detect a combustion pressure by detecting a change in load generated in the transmission unit 30 (rod-like member 30a) via the pressure receiving unit 10 due to the combustion pressure. Thereby, since the whole transmission part 30 (bar-shaped member 30a) is included in the housing 60, handling of the combustion pressure sensor 1 becomes easy and assembly workability | operativity improves.

本例では、検出部２０として圧電素子からなる荷重検出器２０ａを採用したが、荷重を電気的信号に変換できる構成の荷重検出器であれば良く、例えば、歪みゲージからなる荷重検出器を採用することもできる。 In this example, the load detector 20a made of a piezoelectric element is employed as the detection unit 20, but any load detector having a configuration capable of converting the load into an electrical signal may be used. For example, a load detector made of a strain gauge is adopted. You can also

なお、本例では、固定部４０は、有底孔１０３の内壁面に形成された被固定部１０６に固定されるように構成されていることとした。これにより、シリンダヘッド１０２に固定用の孔等の機構を別途設けることなく、燃焼圧センサ１を固定することができるため、燃焼圧センサ１の設置スペースを小さくすることができる。また、燃焼圧センサ１に別途固定用の部材を設ける必要がないため、燃焼圧センサ１の小型化に寄与する。なお、固定部４０による固定方法は、本例の方法に限定されず、公知の方法を適宜適用することができる。 In this example, the fixing portion 40 is configured to be fixed to the fixed portion 106 formed on the inner wall surface of the bottomed hole 103. As a result, the combustion pressure sensor 1 can be fixed without separately providing a mechanism such as a fixing hole in the cylinder head 102, so that the installation space for the combustion pressure sensor 1 can be reduced. Further, since it is not necessary to provide a separate fixing member for the combustion pressure sensor 1, it contributes to downsizing of the combustion pressure sensor 1. In addition, the fixing method by the fixing | fixed part 40 is not limited to the method of this example, A well-known method can be applied suitably.

以上のごとく、本例によれば、経時的に燃焼圧の検出精度が低下することが防止される燃焼圧センサ１を提供することができる。 As described above, according to this example, it is possible to provide the combustion pressure sensor 1 in which the detection accuracy of the combustion pressure is prevented from decreasing with time.

（実施例２）
本例の燃焼圧センサ１は、図２に示すように、ハウジング６０が伝達部３０の側面２３の少なくとも一部（本例では、側面１３の全部）を覆うとともに、ハウジング６０と伝達部３０の側面２３との間には緩衝部材２５が設けられている。伝達部３０の側面２３における軸方向Ｙの略中央には環状に形成された環状凹部２４が設けられている。緩衝部材２５としての樹脂製のＯリングが環状凹部２４に嵌装されている。本例では、緩衝部材２５は環状凹部２４に嵌装された状態で、ハウジング６０の内面６２に接している。 (Example 2)
In the combustion pressure sensor 1 of this example, as shown in FIG. 2, the housing 60 covers at least a part of the side surface 23 of the transmission portion 30 (in this example, the entire side surface 13), and the housing 60 and the transmission portion 30. A buffer member 25 is provided between the side surface 23. An annular recess 24 formed in an annular shape is provided at the approximate center in the axial direction Y on the side surface 23 of the transmission portion 30. A resin O-ring as the buffer member 25 is fitted in the annular recess 24. In this example, the buffer member 25 is in contact with the inner surface 62 of the housing 60 in a state of being fitted in the annular recess 24.

本例の燃焼圧センサ１によれば、ハウジング６０と伝達部３０の側面２３との間に設けられた緩衝部材２５により、伝達部３０の軸方向Ｙの変位を規制することなく軸方向Ｙに交差する方向への伝達部３０のブレが抑制される。これにより、内燃機関の振動に基づくノイズを低減して、伝達部３０による燃焼圧の伝達精度を一層向上することができ、燃焼圧の検出精度の一層の向上を図ることができる。なお、本例においても、実施例１の場合の作用効果と同等の作用効果を奏する。 According to the combustion pressure sensor 1 of the present example, the buffer member 25 provided between the housing 60 and the side surface 23 of the transmission unit 30 causes the displacement in the axial direction Y of the transmission unit 30 to be restricted in the axial direction Y without being restricted. The blurring of the transmission unit 30 in the intersecting direction is suppressed. Thereby, the noise based on the vibration of the internal combustion engine can be reduced, the transmission accuracy of the combustion pressure by the transmission unit 30 can be further improved, and the detection accuracy of the combustion pressure can be further improved. In addition, also in this example, there exists an effect equivalent to the effect in the case of Example 1.

なお、緩衝部材２５は、Ｏリングに限らず、伝達部３０の側面２３とハウジング６０の内面６２との間に設けられて、伝達部３０の軸方向Ｙの変位を規制することなく軸方向Ｙに交差する方向への伝達部３０のブレを抑制するものであればよい。また、緩衝部材２５を設ける位置は、伝達部３０の軸方向Ｙの変位を規制することなく軸方向Ｙに交差する方向への伝達部３０のブレを抑制することができる位置であればよい。また、複数の緩衝部材２５を軸方向Ｙに異なる位置に設けることとしてもよい。 The buffer member 25 is not limited to the O-ring, and is provided between the side surface 23 of the transmission unit 30 and the inner surface 62 of the housing 60, and the axial direction Y without restricting the displacement in the axial direction Y of the transmission unit 30. What is necessary is just to suppress the blurring of the transmission unit 30 in the direction intersecting with. Further, the position where the buffer member 25 is provided may be a position that can suppress the shaking of the transmission unit 30 in the direction intersecting the axial direction Y without restricting the displacement of the transmission unit 30 in the axial direction Y. Further, the plurality of buffer members 25 may be provided at different positions in the axial direction Y.

（実施例３）
本例の燃焼圧センサ１は、図３に示すように、検出部２０を形成する荷重検出器２０ａと、伝達部３０を形成する棒状部材３０ａと、荷重検出器２０ａと棒状部材３０ａとを保持するハウジング６０とを備える。そして、受圧部１０はハウジング６０から露出された棒状部材３０ａの先端３１０からなり、棒状部材３０ａの後端３２には荷重検出器２０ａが接続されている。荷重検出器２０ａは燃焼圧により受圧部１０を介して棒状部材３０ａに生じた荷重の変化を検知して燃焼圧を検出するように構成されている。 (Example 3)
As shown in FIG. 3, the combustion pressure sensor 1 of this example holds a load detector 20 a that forms a detection unit 20, a rod-shaped member 30 a that forms a transmission unit 30, and a load detector 20 a and a rod-shaped member 30 a. Housing 60. The pressure receiving unit 10 includes a tip 310 of the rod-shaped member 30a exposed from the housing 60, and a load detector 20a is connected to the rear end 32 of the rod-shaped member 30a. The load detector 20a is configured to detect a combustion pressure by detecting a change in the load generated in the rod-shaped member 30a via the pressure receiving portion 10 due to the combustion pressure.

すなわち、本例の燃焼圧センサ１では、実施例１における先端被覆部６１（図１参照）が形成されておらず、ハウジング６０のＹ１方向の端部に開口するよう形成された端部開口部６３を介して、伝達部３０（棒状部材３０ａ）の先端３１０がハウジング６０の外側に露出して底部１０４に当接している。なお、実施例１の場合と同等の構成要素には、同一の符号を付してその説明を省略する。本例の燃焼圧センサ１によれば、実施例１において先端被覆部６１が形成されていることによる作用効果を除いて、実施例１の場合と同等の作用効果を奏する。 That is, in the combustion pressure sensor 1 of the present example, the end covering portion 61 (see FIG. 1) in the first embodiment is not formed, and the end opening portion formed to open at the end portion in the Y1 direction of the housing 60. The tip 310 of the transmission part 30 (bar-shaped member 30 a) is exposed to the outside of the housing 60 and contacts the bottom part 104 through 63. In addition, the same code | symbol is attached | subjected to the component equivalent to the case of Example 1, and the description is abbreviate | omitted. According to the combustion pressure sensor 1 of this example, the same operational effects as in the case of the first embodiment are obtained except for the operational effects due to the formation of the tip covering portion 61 in the first embodiment.

１燃焼圧センサ
１０受圧部
１５緩衝部材
２０検出部
３０伝達部
４０固定部
６０ハウジング
６１先端被覆部
１０３有底孔
１０４底部
１０６被固定部 DESCRIPTION OF SYMBOLS 1 Combustion pressure sensor 10 Pressure receiving part 15 Buffer member 20 Detection part 30 Transmission part 40 Fixing part 60 Housing 61 Tip covering part 103 Bottomed hole 104 Bottom part 106 Fixed part

Claims

A combustion pressure sensor (1) for detecting a combustion pressure in a combustion chamber (101) of an internal combustion engine (100),
The combustion chamber (101) is in contact with the bottom (104) of a bottomed hole (103) formed in the cylinder head (102) so as to open to the outside of the cylinder head (102) constituting the combustion chamber (101). 101) a pressure receiving part (10) configured to receive the combustion pressure in
A detection unit (20) for detecting the combustion pressure received by the pressure receiving unit (10);
A transmission section (30) for transmitting the combustion pressure received by the pressure receiving section (10) to the detection section (20);
A fixing part (40) fixable to the cylinder head (102);
A housing (60) for holding the detection unit (20) and the transmission unit (30);
Equipped with a,
The transmission part (30) is composed of a rod-shaped member (30a) extending in the axial direction,
The detection unit (20) includes a load detector (20a) including a piezoelectric element,
The lower surface (21) located on the front end side in the axial direction of the detection unit (20) is in axial contact with the rear end (32) in the axial direction of the transmission unit (30),
The detector upper surface located on the rear end side in the axial direction in the (20) (22), combustion characterized that you have contact with the fixing member fixed to the housing (60) (50) in the axial direction Pressure sensor (1).

Upper Symbol pressure receiving portion (10), the tip of the rodlike member said housing (60) which is formed in the distal end covering portion covers the front end (31) of (30a) consists of (61), said rod member (30a) ( 31) is in contact with the inner side surface (61a) of the pressure receiving portion (10), and the load detector (20a) is connected to the rear end (32) of the rod-like member (30a) to detect the load. The vessel (20a) is configured to detect the combustion pressure by detecting a change in load generated in the rod-like member (30a) via the pressure receiving portion (10) by the combustion pressure. The combustion pressure sensor (1) according to claim 1.

Upper Symbol pressure receiving portion (10) is made from the tip (310) of said rod-like member that is exposed from the housing (60) (30a), the load detector in the rear end (32) of said rod member (30a) ( 20a) is connected, and the load detector (20a) detects the change in the load generated in the rod-shaped member (30a) via the pressure receiving part (10) by the combustion pressure to detect the combustion pressure. The combustion pressure sensor (1) according to claim 1, wherein the combustion pressure sensor (1) is configured as described above.

The housing (60) covers at least a part of the side surface (33) of the transmission part (30), and a buffer member (between the housing (60) and the side surface (33) of the transmission part (30)). 35) A combustion pressure sensor (1) according to claim 2 or 3, characterized in that 35) is provided.

The said pressure receiving part (10) has a shape where the corner | angular part inclined so that the said bottom part (104) of the said bottomed hole (103) formed in the shape of a mortar could be followed. Combustion pressure sensor (1) given in any 1 paragraph.