JP2009063256A - Glow plug with combustion pressure sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a glow plug with a combustion pressure sensor capable of carrying out miniaturization and improving durability. <P>SOLUTION: A pressure detecting mechanism 10 is housed in an interior of a housing 1 of the glow plug 100 with a combustion pressure sensor. The pressure detecting mechanism 10 is provided with a pressure detecting element 11. The pressure detecting element 11 is fixed to a tip side of a wiring board 12 arranged in a rear end side than the pressure detecting element 11. A signal conductor 120 for transmitting a signal or the like outputted from the pressure detecting element 11, and an electric power supply conductor 121 for energizing a heater 23 and carrying out heating are formed on the wiring board 12. A pressure transmitting mechanism 20 for transmitting the combustion pressure of the engine to the pressure detecting element 11 is provided in a tip side more than the pressure detecting element 11. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a glow plug with a combustion pressure sensor used for an internal combustion engine such as an automobile engine.

Conventionally, as a glow plug with a combustion pressure sensor, for example, a structure in which a pressure detection element is attached to a metal diaphragm is known (see, for example, Patent Document 1). However, since the glow plug with a combustion pressure sensor having such a structure has a metal diaphragm, the size of the pressure detection unit increases, and the number of parts increases, which makes it difficult to reduce the size. is there. Further, a glow plug with a combustion pressure sensor in which a pressure sensor is pressed by a pressure transmission member including a heater is known (for example, see Patent Document 2). However, the glow plug with a combustion pressure sensor has a configuration in which an element electrode extraction portion and a heater electrode extraction lead wire are provided. For this reason, there is a possibility that damage to the lead wire part or element may occur due to the problem that it is difficult to reduce the size, the slack of the lead wire during production, the influence of vibration, etc. There is a problem that it is difficult to improve the performance.
JP 2005-90954 A WO2006 / 027280

  As described above, the prior art has a problem that it cannot be reduced in size and a problem that it is difficult to improve durability.

  The present invention has been made to solve the above problems. An object of the present invention is to provide a glow plug with a combustion pressure sensor that can be reduced in size and can improve durability.

  A glow plug with a combustion pressure sensor according to the present invention includes a housing formed in a cylindrical shape, a heating element having its tip end protruded from the tip of the housing, and its rear end housed in the housing, A pressure detection element that is provided in the housing on the rear end side of the heating element, is directly or indirectly joined to the heating element, and detects the pressure in the combustion chamber transmitted through the heating element. A glow plug with a combustion pressure sensor, provided in the housing on the rear end side of the pressure detection element, and a signal conductor for transmitting an electrical signal of the pressure detection element, and the heating element It has a wiring board on which a power supply conductor for energizing to heat the heating element is formed.

  In the above glow plug with a combustion pressure sensor of the present invention, the wiring board on which the signal conductor for transmitting the signal of the pressure detection element and the power supply conductor for energizing the heating element to generate heat are formed. In addition, electrical extraction to the rear end side of the pressure detection element and the heating element is performed. As a result, as in the case where electrical lead out to the rear end side is performed by the lead wire, the lead wire portion and the element are damaged due to slack, vibration, etc. of the lead wire during manufacturing. There is no possibility, and durability can be improved. In addition, the signal conductor and the power supply conductor can be integrated and arranged on one wiring board, thereby reducing the size.

  The wiring board is preferably made of a ceramic that easily obtains heat resistance and corrosion resistance from the viewpoint of heat resistance and corrosion resistance. The wiring board is preferably a multilayer wiring board in which a plurality of conductor layers are formed. As a result, it is possible to further reduce the size and improve the corrosion resistance of the wiring portion.

  When the wiring board is a multilayer wiring board, the signal conductor and the power supply conductor are preferably formed in different layers of the wiring board. Thereby, it is possible to suppress the generation of noise in the signal conductor due to a large current flowing through the power supply conductor.

  In order to reduce the influence of such noise, it is preferable to form a first shield conductor made of a conductor layer having a ground potential between the signal conductor and the power supply conductor. A second shield conductor composed of a conductor layer having a ground potential is formed on a layer opposite to the first shield conductor with respect to the signal conductor, and the signal conductor is formed by the second shield conductor and the first shield conductor. It is preferable to adopt a configuration in which the is sandwiched.

  It is preferable that the pressure detection element is fixedly disposed on the end portion of the wiring board with an adhesive or the like. In this way, it is not necessary to separately provide a pedestal for supporting the pressure detection element, and the size can be reduced, and the terminal of the pressure detection element and the signal conductor of the wiring board can be easily connected.

  Further, in the glow plug with the combustion pressure sensor, the heating element holding member, an inner ring part for holding the heating element, an outer ring part joined to the housing, the inner ring part and the outer ring part, A heating element holding member consisting of a flexible connecting portion, and an intermediate connecting member, which is a cylindrical body having a flange projecting radially outward at its distal end side, And an intermediate connection member to which the wiring board holding member is joined to the rear end side of the heating element holding member, and the wiring board is connected to the wiring board holding member. It can be set as the structure currently hold | maintained. In this case, the wiring board is formed with a wide central portion with respect to its front and rear ends, and the widened portion of the central portion is locked in the axial direction and held by the wiring board holding member. Preferably, the conductor is not formed in the widened portion of the central portion of the wiring board. Or when forming a conductor in the widened site | part, it is good to form insulating films, such as glass, on the outermost surface. Furthermore, in this case, the pressure detection element can be configured to be fixed to the housing in a mechanically rigid state on the rear end side on the axis of the heating element via the intermediate holding member. .

  In the glow plug with the combustion pressure sensor configured as described above, since the heating element is held by the heating element holding member having a flexible connecting portion, when the combustion pressure is applied to the leading end of the heating element, the rear end in the axial direction And the combustion pressure is efficiently transmitted to the pressure detection element. In addition, when the glow plug with the combustion pressure sensor is attached to the engine and the seat surface of the housing is in pressure contact with the engine, the pressure sensitive part is Therefore, it is possible to prevent the pressure due to the deformation of the housing from being applied to the pressure detecting element without being affected by the deformation of the housing. Thereby, the pressure detection accuracy can be improved. Further, since the wiring board is held with respect to the housing by the intermediate connection member and the wiring board holding member joined to the intermediate member, the pressure detection element is provided at the end on the front end side of the wiring board. The detection element can be fixed to the housing in a mechanically rigid state on the rear end side on the axis of the heating element via the intermediate holding member. With this configuration, the pressure detection element can be pressed by the displacement of the heating element without using a metal diaphragm or the like. As a result, the number of components can be reduced, the size can be reduced, the pressure can be directly detected, and a good combustion pressure detection sensitivity can be obtained.

  ADVANTAGE OF THE INVENTION According to this invention, while being able to achieve size reduction, the glow plug with a combustion pressure sensor which can aim at the improvement of durability can be provided.

  Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show a configuration of a glow plug 100 with a combustion pressure sensor according to an embodiment of the present invention. FIG. 1 is a cross-sectional view showing an overall configuration in a direction including an axis, and FIG. 2 shows an axis. FIG. 2 is an enlarged cross-sectional view of a main part in a direction different from 90 ° (direction perpendicular to the paper surface of FIG. 1).

  As shown in FIG. 1, a glow plug 100 with a combustion pressure sensor includes a housing 1 made of a metal such as carbon steel and formed in a substantially cylindrical shape. On the outer peripheral surface of the housing 1, there is formed a screw portion 2 for attaching the glow plug 100 with a combustion pressure sensor to an engine (engine) not shown. A tool engaging portion 3 that engages a tool such as a spanner or a wrench when the glow plug 100 with the combustion pressure sensor is attached to the engine is provided on the outer peripheral portion on the rear end side of the screw portion 2.

  A pressure detection mechanism 10 is accommodated in the housing 1. The pressure detection mechanism 10 includes a pressure detection element 11. The pressure detection element 11 is disposed on the rear end side of the pressure detection element 11 and is fixed to the front end side of the wiring substrate 12 also serving as a pedestal with glass paste or an adhesive. The wiring board 12 is made of an insulating ceramic such as alumina, and is held from the outer periphery by a board holding member 40. The board holding member 40 is formed in a substantially cylindrical shape, and holds both side ends of the wiring board 12 in a state in which the wiring board 12 is accommodated therein. A connecting member 30 formed in a substantially cylindrical shape is connected to the distal end side of the substrate holding member 40. A pressure transmission mechanism 20 for transmitting the combustion pressure of the engine to the pressure detection element 11 is provided on the tip side of the pressure detection element 11. In the pressure transmission mechanism 20, the front end surface is a pressure receiving surface 21, and the rear end surface is a pressing surface 22 that presses the pressure detecting element 11. The pressure detection mechanism 11 is configured by integrating the pressure detection element 11, the wiring substrate 12, the pressure transmission mechanism 20, the connection member 30, and the substrate holding member 40.

  As shown in FIG. 2, the pressure transmission mechanism 20 includes a rod-like (substantially cylindrical) heater 23 that functions as a heating element, a metal annular member 24, an element pressing member 25, and an intermediate member 26. . The metal annular member 24, the element pressing member 25, and the intermediate member 26 are all made of metal (conductor), and are made of SUS430, Ni alloy or Kovar, and SUS430, respectively. A metal annular member 24 is connected to the rear end side of the heater 23 provided on the front end side, and an element pressing member 25 is connected to the rear end side of the metal annular member 24, and the element pressing member 25 and the pressure detection element 11 are connected. An intermediate member 26 is disposed between the two. With these configurations, the combustion pressure of the engine can be transmitted to the pressure detecting element 11.

  In the present embodiment, the heater 23 is configured as a heating element in which a heating resistor (not shown) made of conductive ceramic and lead members 231 and 232 are embedded in an insulating ceramic base 230. Yes. Both of the lead members 231 and 232 are partly exposed at the rear end side of the heater 23 from the side peripheral surface of the heater 23 to form electrode extraction portions 233 and 234. One electrode extraction portion 233 is grounded to the engine via the connection member 30 and the housing 1 by contacting an inner ring portion 152 of the cap member 150 described later. The other electrode extraction part 234 is connected to a power supply conductor 121 of the wiring board 12 described later via the metal annular member 24, the element pressing member 25, and the intermediate member 26 by contacting the metal annular member 24, and generates heat. Power is supplied to the resistor.

  As shown in FIGS. 3 and 4, the wiring board 12 has a plurality of signal conductors 120 for transmitting a signal output from the pressure detection element 11 and power supply for energizing the heater 23 to generate heat. A conductor 121 is formed. As shown in FIG. 4, the signal conductor 120 is formed on both surfaces of the wiring board 12, and the power supply conductor 121 is formed only on one surface. Since the current flowing through the power supply conductor 121 is larger than the current flowing through the signal conductor 120, the power supply conductor 121 is thicker and wider than the signal conductor 120. The power supply conductor 121 is electrically connected to the intermediate member 26 via a conductive plate 130 made of, for example, Al or Ni. The power supply conductor 121 is electrically connected to the heater 23 via the plate 130, the intermediate member 26, the element pressing member 25, and the metal annular member 24. On the other hand, the signal conductor 120 is electrically connected to the pressure detection element 11 by a wire or the like.

  The plate 130 is fixed to the power supply conductor 121 and the intermediate member 26 by conductive adhesive or welding. However, instead of the plate 130, a wire or the like is joined to the power supply conductor 121. The intermediate member 26 may be connected. Further, the intermediate member 26 and the plate 130 may be integrally formed. Since a current of, for example, about 7 A flows through the electrical path for energizing the heater, the power supply conductor 121 and the like are preferably made of a metal having a low electrical resistance, such as gold, silver, copper, or the like. As shown in FIGS. 1 and 2, the wiring board 12 is accommodated in the housing 1 via the board holding member 40 from the outer periphery. The wiring board 12 is prepared by mixing raw material powders, producing a green sheet, and firing it in the same manner as in producing a general ceramic mechanical part. Next, the wiring substrate 12 can be obtained by forming a conductive path on the substrate with the above-described conductive paste using the metal and baking the conductive path. Further, as shown in FIG. 3, the wiring board 12 has a widened portion 125 formed wide at the center portion with respect to its front and rear ends. The widened portion 125 is not formed with the above-described conductor, and is locked by the substrate holding member 40 at this portion.

  The connecting member 30 is a metal member made of SUS430 and has a substantially cylindrical shape. The flange fixing portion 14 is formed so that the front end side is thick and swells in the radial direction, and the rear end side from the flange fixing portion 14 is configured as a thin cylindrical portion 301. In the present embodiment, the inner diameter of the cylindrical portion 301 is fitted to be approximately the same as the outer diameter of the front end portion of the substrate holding member 40 so as to hold the substrate holding member 40 and is held by press fitting and welding.

  In addition, the substrate holding member 40 is made of a plurality of members having a substantially cylindrical shape made of metal such as SUS430 (in the example shown in FIG. 2, three of the front end side member 401, the intermediate member 402, and the rear end side member 403). It is configured to be connected in the axial direction. Among these members, the front end side member 401 and the rear end side member 403 are configured to be thicker than the intermediate member 402. The front end side member 401 and the rear end side member 403 are shown in FIG. The front end portion and the rear end portion of the widened portion 125 at the center portion of the wiring substrate 12 are supported.

  Thus, in this embodiment, the pressure detection element 11 and the heater 23 are electrically drawn out to the rear end side of the housing 1 by the wiring board 12 on which the signal conductor 120 and the power supply conductor 121 are formed. As a result, the lead wire is not slackened at the time of manufacture unlike the case where the lead wire is electrically pulled out to the rear end side. For this reason, since the breakage of the lead wire due to vibration does not occur, the reliability can be improved. In the glow plug 100 with the combustion pressure sensor, the part where the wiring board 12 is disposed is the tip side from the screw part 2, and is a part exposed to high temperature when used in the engine. . For this reason, it is preferable to comprise the wiring board 12 with the ceramic which has heat resistance and corrosion resistance.

  In the wiring board 12 shown in FIGS. 3 and 4, the signal conductor 120 and the power supply conductor 121 are formed on the same surface. However, like the wiring board 112 shown in FIGS. 120 is formed on one surface (see FIG. 5), the power supply conductor 121 is formed on the other surface (see FIG. 7), and the signal conductor 120 and the power supply conductor 121 are connected to the wiring board 112. (See FIG. 6). In this case, the occurrence of noise in the signal conductor 120 due to the current flowing in the power supply conductor 121 can be reduced.

  Further, from the viewpoint of preventing deterioration such as oxidation and corrosion of the wiring portion, the signal conductor 120 and the power supply conductor 121 are provided on the inner layer of the multilayer wiring board as in the wiring board 212 shown in FIG. It is preferable to form. Furthermore, in order to reduce the influence of noise on the signal conductor 120 due to the current flowing in the power supply conductor 121, the signal conductor 120 and the power supply conductor 121 can be connected as shown in a wiring board 312 shown in FIG. 9. It is preferable to provide a shield conductor 122 having a ground potential on substantially the entire surface of the wiring board 312 so as to be interposed therebetween.

  Further, in the wiring substrate 412 shown in FIG. 10, a shield conductor 122 is interposed between the signal conductor 120 and the power supply conductor 121, and the power supply conductor 121 is provided on the surface layer of the substrate.

  In the wiring board 512 shown in FIG. 11, a shield conductor 122 is provided between the signal conductor 120 and the power supply conductor 121, and a second shield is provided on the opposite side of the signal conductor 120 from the shield conductor 122. A shield conductor 123 is provided as a conductor, and shield conductors 122 and 123 are provided on both sides of the signal conductor 120. Further, in the wiring substrate 612 shown in FIG. 12, the shield conductor 123 of the wiring substrate 512 in FIG. 11 is provided so as to be exposed on one substrate surface. The wiring boards 112, 212, 312, 412, 512, and 612 configured as described above can also be used. In order to fabricate the wiring boards 212, 312, 412, 512, and 612 as shown in FIGS. 8 to 12, the conductive paths of the signal conductor 120 and the power supply conductor 121 are formed on a plurality of individually produced ceramic substrates. It may be formed in the same manner as a general ceramic multilayer substrate in which a via is formed, a via (hole) is filled, a conductor is filled in the via, and coating is performed to achieve conduction between layers.

  As shown in FIGS. 1 and 2, a flange fixing portion 14 is formed at the tip of the connection member 30 to which the substrate holding member 40 for holding the wiring substrate 12 is connected. On the other hand, a cap member 150 for sealing the tip portion is provided at the tip portion of the housing 1. The flange fixing portion 14 is integrated by welding or the like so as to be sandwiched between the rear end side of the cap member 150 and the front end side of the housing 1. A taper-shaped sheet surface 151 is formed on the front end side of the cap member 150 so as to be in close contact with the engine. In addition, the cap member 150 has an electrical continuity function with the heater 23 and also has a function of holding the heater 23 displaceably with respect to the housing 1. That is, the cap member 150 that also serves as the heater holding member includes an inner ring portion 152 that holds the heater 23, an outer ring portion 153 that is joined to the housing 1, and a thin wall that connects the inner ring portion 152 and the outer ring portion 153. And a connecting portion 154 having flexibility. Thus, since the connection part 154 made thin is provided in the inner peripheral part of the seat surface 51 of the cap member 50, the heater 23 is provided with respect to the seat surface 51 and the housing 1 due to fluctuations in combustion pressure of the engine. It is relatively displaceable.

  As described above, the pressure detection element 11, the wiring board 12, the pressure transmission mechanism 20, the connection member 30, and the board holding member 40 are integrated to form the pressure detection mechanism 10, and the flange fixing portion 14 of the pressure detection mechanism 10. Is held in the housing 1 so as to be sandwiched between the rear end side of the cap member 50 and the front end side of the housing 1. Thus, since the integrated pressure detection mechanism 10 is fixed to the housing 1 at only one location of the flange fixing portion 14, even when the housing 1 is deformed so as to bend, the pressure due to the deformation is detected by the pressure detection. The structure does not add to the element 11.

  On the rear end side of the wiring board 12, a flexible board 50 for drawing out an output signal from the pressure detection element 12, and a power supply wiring 51 for supplying power to the heater 23 are the signal conductor 120 and the power supply described above. It is arranged in a state of being electrically connected to the conductor 121 and is electrically drawn out to the rear end of the housing 1. The flexible substrate 50 can be provided with a signal processing circuit for processing an output signal from the pressure detection element 11. This signal is input to a control device such as an ECU, and a change in combustion pressure in the engine (engine) is detected.

  The glow plug 100 with the combustion pressure sensor configured as described above is attached to the internal combustion engine so that the tip side is located in the combustion chamber, and assists the start of the internal combustion engine by energizing the heater 23 to generate heat. Further, when the pressure in the combustion chamber is applied to the pressure receiving surface 21 at the front end of the heater 23, the heater 23, the pressing member 25, and the intermediate member 26 are slightly displaced toward the rear end side, and thus via the pressure transmission mechanism 20. The pressure is efficiently transmitted to the pressure detection element 11.

  The pressure detection element 11 is composed of, for example, an Si element or an SOI element, and is configured to output an electrical signal corresponding to strain when pressure is applied. When the pressure detection element 11 is configured, as shown in FIG. 13, a structure in which an element 61 such as an Si element or an SOI element is bonded to a substrate 60 made of glass, metal, or the like can be employed. A piezoresistor is formed on the surface of the element 61, and pressure is detected from a change in resistance value when the element 61 is pressed.

  In the glow plug 100 with the combustion pressure sensor of the present embodiment, the pressure detection element 11 formed as described above is arranged on the wiring board 12 also serving as a base and is directly pressed by the pressure transmission mechanism 10. Therefore, the number of components can be reduced, and the size can be reduced as compared with the conventional case. In addition, since the pressure is directly detected, good combustion pressure detection sensitivity can be obtained.

  Further, since the pressure detection mechanism 10 is supported by the housing 1 at only one portion of the flange fixing portion 14, it is not affected by the distortion of the housing 1 due to the cylinder head deformation, and noise caused by vibrations or the like is generated. Can be reduced. Furthermore, in the glow plug 100 with the combustion pressure sensor, the length of the pressure transmission mechanism 20 is shorter than that of the housing 1, and the structure is supported by the housing 1 on the front end side of the glow plug 100 with the burning pressure sensor. Therefore, the resonance frequency in the pressure transmission mechanism 20 is high. For this reason, it is a structure which is hard to resonate with the periodic noise of the axial direction added to a pressure transmission mechanism by a combustion cycle. Therefore, it is possible to prevent a decrease in detection accuracy due to resonance with noise.

  In the above, the present invention has been described with reference to the embodiment. However, the present invention is not limited to the above-described embodiment and the like, and it is needless to say that the present invention can be appropriately modified and applied without departing from the gist thereof.

Sectional drawing which shows the whole structure of the glow plug with a combustion pressure sensor which concerns on embodiment of this invention. Sectional drawing which expands and shows the principal part of the glow plug with a combustion pressure sensor of FIG. The upper side figure which expands and shows the wiring board of the glow plug with a combustion pressure sensor of FIG. The side view of the wiring board of FIG. The top view which shows the example of another wiring board. The side view of the wiring board of FIG. The bottom view of the wiring board of FIG. The longitudinal cross-sectional view which shows the example of another wiring board. The longitudinal cross-sectional view which shows the example of another wiring board. The longitudinal cross-sectional view which shows the example of another wiring board. The longitudinal cross-sectional view which shows the example of another wiring board. The longitudinal cross-sectional view which shows the example of another wiring board. The figure for demonstrating the structure of a pressure detection element.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Housing, 2 ... Screw part, 3 ... Tool engaging part, 10 ... Pressure detection mechanism, 11 ... Pressure detection element, 12 ... Wiring board, 20 ... Pressure transmission mechanism, 21 ... Pressure receiving Surface, 22 ... Pressing surface, 23 ... Heater, 30 ... Connecting member, 100 ... Glow plug with combustion pressure sensor.

Claims (11)

A housing formed in a cylindrical shape;
A heating element having its own tip protruded from the tip of the housing, and its rear end housed in the housing;
A pressure detection element that is provided in the housing on the rear end side of the heating element, is directly or indirectly joined to the heating element, and detects the pressure in the combustion chamber transmitted through the heating element. When,
Glow plug with combustion pressure sensor equipped with
A signal conductor provided in the housing on the rear end side of the pressure detection element for transmitting an electric signal of the pressure detection element, and a power supply for energizing the heating element to cause the heating element to generate heat A glow plug with a combustion pressure sensor, characterized by comprising a wiring board on which a conductor is formed. The glow plug with a combustion pressure sensor according to claim 1,
A glow plug with a combustion pressure sensor, wherein the wiring board is made of ceramic. The glow plug with a combustion pressure sensor according to claim 1 or 2,
A glow plug with a combustion pressure sensor, wherein the wiring board is a multilayer wiring board having a plurality of conductor layers. The glow plug with a combustion pressure sensor according to claim 3,
A glow plug with a combustion pressure sensor, wherein the signal conductor and the power supply conductor are formed in different layers of the wiring board. The glow plug with a combustion pressure sensor according to claim 4,
A glow plug with a combustion pressure sensor, wherein a first shield conductor made of a conductor layer having a ground potential is formed between the signal conductor and the power supply conductor. The glow plug with a combustion pressure sensor according to claim 5,
A second shield conductor made of a conductor layer having a ground potential is formed on a layer opposite to the first shield conductor with respect to the signal conductor, and the second shield conductor and the first shield conductor A glow plug with a combustion pressure sensor, wherein the signal conductor is sandwiched. The glow plug with a combustion pressure sensor according to any one of claims 1 to 6,
A glow plug with a combustion pressure sensor, wherein the pressure detection element is disposed at an end of the wiring board. The glow plug with a combustion pressure sensor according to any one of claims 1 to 7,
A heating element holding member,
A heating element holding member comprising an inner ring part that holds the heating element, an outer ring part that is joined to the housing, and a flexible connection part that connects the inner ring part and the outer ring part;
An intermediate connecting member,
It consists of a cylindrical body having a flange projecting radially outward on its front end side, and the flange is joined to the outer ring of the heating element holding member, while holding the wiring board on its rear end An intermediate connecting member to which the members are joined;
Have
A glow plug with a combustion pressure sensor, wherein the wiring board is held by the wiring board holding member. The glow plug with a combustion pressure sensor according to claim 8,
The wiring board has a wide central portion with respect to its front and rear ends, and the widened portion of the central portion is axially locked and held by the wiring board holding member. Glow plug with combustion pressure sensor. The glow plug with a combustion pressure sensor according to claim 9,
A glow plug with a combustion pressure sensor, wherein the conductor is not formed in the widened portion of the central portion of the wiring board. In the glow plug with a combustion pressure sensor according to any one of claims 8 to 10,
The glow with a combustion pressure sensor, wherein the pressure detecting element is fixed to the housing in a mechanically rigid state on the rear end side on the axis of the heating element via the intermediate holding member. plug.

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