JP2007187609A - Structure of mounting pressure sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent deposit from a combustion chamber from leaking into a gap between the part of a combustion chamber side and the engine rather than a sealing face in a shell part, in a structure for attaching a pressure sensor detecting the pressure of the combustion chamber of the engine, by attaching the pressure sensor having a cylindrical shell part to the engine. <P>SOLUTION: The pressure sensor 100, having the seal face 33 on the part of the other end rather than one end out of the outer face of the shell part 1 by having a pressure receiving part 10 on one end of the cylindrical shell part 1 is inserted from one end side of the shell part 1 in an attaching hole 201 of the engine, sealed by adhering the seal face 33 on the inner face of the attaching hole 201, and provided with a sealing member 300 for sealing between the part and the inner face of the attaching hole 201 opposite thereto on the part of one end side rather than the sealing face 33 out of the outer face of the shell part 1. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a pressure sensor mounting structure in which a pressure sensor is mounted on an engine and the pressure in a combustion chamber of the engine is detected.

  Conventionally, as a general pressure sensor mounting structure of this type, for example, a structure described in Patent Document 1 has been proposed.

  In this device, the pressure sensor has a diaphragm as a pressure receiving portion that receives pressure at one end portion of the cylindrical body portion, and the body portion is provided in the engine from the one end portion side. It is inserted and installed in the mounting hole leading to.

Here, a seal surface is provided on a portion of the outer surface of the body portion of the pressure sensor that is closer to the other end portion than the one end portion of the body portion, and this seal surface is in close contact with the inner surface of the mounting hole for sealing. Thus, the cylinder pressure, that is, the pressure in the combustion chamber is received by the pressure receiving portion.
JP 2005-43364 A

  However, in the conventional mounting structure described above, the body portion of the pressure sensor is sealed against the mounting hole at the sealing surface, but the mounting hole and the body are located closer to the combustion chamber than the sealing portion by the sealing surface. There is a gap between them.

  That is, since there is a gap between the engine and the part on the one end side of the seal surface in the body part, a deposit made of soot after combustion enters the gap from the combustion chamber.

  Then, this deposit causes the part of the pressure sensor body part on one end side of the pressure sensor to adhere to the engine. Therefore, when the pressure sensor is removed from the engine during adjustment or replacement, the pressure sensor cannot be removed from the engine. Or the pressure sensor is damaged.

  The present invention has been made in view of the above problems, and in a pressure sensor mounting structure in which a pressure sensor having a cylindrical body is mounted on an engine to detect the pressure of the combustion chamber of the engine, the combustion chamber The purpose of this is to prevent the deposits from entering the gap between the engine chamber and the part closer to the combustion chamber than the seal surface in the body.

  In order to achieve the above object, the present invention provides an outer surface of the body part (1) on one end side of the body part (1) with respect to the sealing surface (33), that is, a part on the combustion chamber (202) side. Sealing members (300, 310, 320) are provided for sealing between the portion and the inner surface of the mounting hole (201) facing the portion.

  According to this, the gap between the body part (1) and the mounting hole (201) is sealed at a position closer to the combustion chamber (202) of the body part (1) than the sealing surface (33) of the body part (1). Since the seal member (300) is provided, the deposit from the combustion chamber (202) is a gap between the portion of the fuselage portion (1) closer to the combustion chamber (202) than the seal surface (33) and the engine (200). (204) can be prevented from entering.

  In addition, the code | symbol in the parenthesis of each means described in a claim and this column is an example which shows a corresponding relationship with the specific means as described in embodiment mentioned later.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, parts that are the same or equivalent to each other are given the same reference numerals in the drawings in order to simplify the description.

(First embodiment)
FIG. 1 is a schematic cross-sectional view showing a structure for mounting the pressure sensor 100 to the engine 200 according to the first embodiment of the present invention.

  The pressure sensor 100 generally includes a cylindrical body part 1 and a connector part 2 connected to the body part 1. Further, the engine 200 is provided with a mounting hole 201 that communicates with the combustion chamber 202, and the body portion 1 of the pressure sensor 100 is inserted into the mounting hole 201 from one end (the lower end in FIG. 1), The engine 200 faces the combustion chamber 202.

  In this example, the body portion 1 is welded sequentially from one end thereof to a pressure receiving diaphragm 10 as a pressure receiving portion, a cylindrical metal case 20, a cylindrical metal stem 30, and a cylindrical housing 40. They are connected and integrated by brazing, bonding, etc. The connector portion 2 is connected to the other end portion of the body portion 1, that is, the housing 40.

  First, the housing 40 is made of metal such as stainless steel, and an attachment portion 41 for fixing the pressure sensor 100 to the attachment hole 201 of the engine 200 is formed on the outer surface of the housing 40. .

  In this example, the attachment portion 41 is configured as a screw portion 41 that can be screwed to the attachment hole 201. That is, the pressure sensor 100 of this example is fixed and attached to the engine 200 by screw connection between the screw portion 41 and the attachment hole 201 as a screw hole.

  The metal stem 30 is a member made of metal such as stainless steel processed into a hollow cylindrical shape, and has an opening 31 at the end on the metal case 20 side and a thin distortion portion 32 with the end on the housing 40 side closed. It has become.

  The strained portion 32 of the metal stem 30 is distorted when the pressure P received by the pressure receiving diaphragm 10 is applied by a pressure transmission mechanism described later. The strain portion 32 is provided with a detection element 50 that generates a signal based on strain due to the pressure P of the strain portion 32.

  In addition, a seal surface 33 that protrudes in a direction orthogonal to the peripheral surface is formed on the entire outer periphery of the metal stem 30. The sealing surface 33 is configured as the sealing surface 33 of the body portion 1 and is a tapered surface whose diameter is increased from the combustion chamber 202 side toward the connector portion 2 side as shown in FIG. .

  Further, the inner surface of the mounting hole 201 facing the seal surface 33 is a tapered seat surface corresponding to the seal surface 33. When the pressure sensor 100 is screw-coupled to the engine 200, the axial force of the pressure sensor 100 causes the seal surface 33 of the body portion 1 and the inner surface of the mounting hole 201 of the engine 200 to come into close contact with each other to provide a seal.

  The metal case 20 is made of metal such as stainless steel, and is fitted into and fixed to the opening 31 of the metal stem 30. The pressure receiving diaphragm 10 is joined to one end of the body 1 of the metal case 20, that is, the end of the body 1 on the combustion chamber 202 side.

  The pressure receiving diaphragm 10 is, for example, a metal circular plate shape such as stainless steel. When the pressure sensor 100 is attached to the engine 200, the pressure P in the combustion chamber 202 is a pressure-receiving diaphragm located at one end of the body 1 as indicated by the white arrow in FIG. 10, the pressure receiving diaphragm 10 is deformed and deformed by the application of the pressure P.

  A pressure transmission member 60 is provided in the space formed by the hollow portion of the metal stem 30 and the hollow portion of the metal case 20. The pressure transmission member 60 is made of, for example, a metal such as stainless steel or ceramic, and has a rod shape in this example.

  Each end of the pressure transmitting member 60 is in contact with the strained portion 32 of the metal stem 30 and the pressure receiving diaphragm 10 in a state where a load is applied, and the pressure P is transmitted from the pressure receiving diaphragm 10 to the pressure transmitting member 60. This is applied to the strained portion 32 of the metal stem 30 via the.

  In this example, the pressure P received by the pressure receiving diaphragm 10 is transmitted to the distortion portion 32 of the metal stem 30 by such a pressure detection mechanism, and a signal is output from the detection element 50 based on the distortion of the distortion portion 32. It is output.

  Further, as shown in FIG. 1, a wiring substrate 42 made of a ceramic substrate or the like is provided inside the housing 40. An IC chip 43 is mounted on the wiring board 42 and is electrically connected to the wiring board 42 by a bonding wire (not shown). The IC chip 43 is formed with a circuit for amplifying and adjusting the output from the detection element 50.

  Further, as shown in FIG. 1, in the housing 40, the IC chip 43 and the detection element 50 are electrically connected by a wiring member 44. Here, as the wiring member 44, a lead wire, a flexible printed circuit board (FPC), or the like is employed.

  The connector portion 2 is connected to the housing 40 via an O-ring 45. The connector portion 2 is made of a resin such as PPS (polyphenylene sulfide), and a metal terminal 2a is integrated with the connector member 2 by insert molding or the like.

  The connector part 2 is assembled to the housing 40 in a state where one end side is inserted into the opening part of the housing 40, and the edge part of the opening part of the housing 40 is caulked to the connector part 2. 40 is fixed integrally.

  In the housing 40, the terminal 2 a of the connector portion 2 is electrically connected to the wiring board 42. The terminal 2a can be electrically connected to an automobile ECU or the like, so that the pressure sensor 100 can exchange signals with the outside.

  As described above, in the mounting structure of the present embodiment, the pressure sensor 100 has the pressure-receiving diaphragm 10 as the pressure-receiving portion at one end portion of the cylindrical body portion 1 and the body portion 1 of the outer surface of the body portion 1. A seal surface 33 is provided at a portion on the other end side with respect to the one end portion, and such a pressure sensor 100 is inserted into the mounting hole 201 of the engine 200 from one end portion side of the body portion 1 and sealed. The pressure P in the combustion chamber 202 can be detected by closely sealing the surface 33 with the inner surface of the mounting hole 201.

  In the present embodiment, a portion of the outer surface of the body portion 1 that is closer to the one end portion of the body portion 1 than the seal surface 33, that is, a portion of the body portion 1 that is closer to the combustion chamber 202 is opposed to this portion. A seal member 300 that seals between the inner surface of the mounting hole 201 is provided.

  2A and 2B are diagrams showing a configuration of a single seal member 300 according to the present embodiment, in which FIG. 2A is a top view and FIG. 2B is a partial cross-sectional perspective view. The seal member 300 of the present embodiment has a ring shape, and has elasticity in the double arrow Y1 direction in FIG. 2B, that is, the direction Y1 orthogonal to the radial direction.

  The seal member 300 of the present embodiment may be a ring shape having elasticity in the direction Y1 orthogonal to the radial direction. In this example, as shown in FIG. 2, the seal member 300 has a circular overall shape. It has a ring shape, and its cross-sectional shape is a C shape, and what is called a C ring is adopted.

  By using such a C-ring as the seal member 300, elasticity is exhibited in a direction orthogonal to the radial direction. The material of the seal member 300 is preferably a material that can withstand the high heat of the combustion flame and has a spring property, and a metal such as stainless steel is suitable.

  As shown in FIG. 1, a portion of the inner surface of the mounting hole 201 that is closer to the combustion chamber 202 than the one end portion of the body portion 1 protrudes so as to overlap the end surface of one end portion of the body portion 1. The protrusion 203 is formed. In this example, the protruding portion 203 overlaps the peripheral portion of the pressure receiving diaphragm 10 which is the end surface of one end portion of the body portion 1.

  The seal member 300 of this embodiment is interposed between the protruding portion 203 of the mounting hole 201 and one end portion of the body portion 1 of the pressure sensor 100, and the direction Y1 orthogonal to the radial direction of the seal member 300. A surface 301 on one side (see FIG. 2B) is in contact with the protruding portion 203, and a surface 302 on the other side (see FIG. 2B) is in contact with the end surface of one end of the body portion 1. It has become.

  In this mounting structure, the seal member 300 is brought into such a contact state, so that the seal member 300 is in a direction orthogonal to the radial direction by the axial force when the pressure sensor 100 is screwed to the engine 200. Elastically deforms to Y1.

  Due to the elastic deformation of the seal member 300, the seal member 300 comes into close contact with both the end surface of the one end portion of the body portion 1 and the protruding portion 203 of the mounting hole 201, and thus the seal by the elasticity of the seal member 300 is performed.

  As described above, since the seal member 300 that seals the gap 204 between the body portion 1 and the mounting hole 201 is provided at a position closer to the combustion chamber 202 of the body portion 33 than the seal surface 33 of the body portion 1, the combustion chamber It is possible to prevent the deposit from 202 from entering the gap 204 between the engine 200 and the portion of the body 1 that is closer to the combustion chamber 202 than the seal surface 33.

  Note that the mounting structure of the pressure sensor 100 according to the present embodiment is such that the pressure sensor 100 is mounted from one end side of the body portion 1 with the seal member 300 installed in the protruding portion 203 in the mounting hole 201. It is formed by inserting into the hole 201 and screwing it through the screw part 41.

  Further, in the present embodiment, the seal by the seal member 300 is an auxiliary seal for preventing the deposit from entering, and the pressure of the combustion chamber 202, that is, the in-cylinder pressure (for example, reaches 10 MPa or more in a supercharged engine) The sealing portion 33 in the sealing surface 33 is securely sealed.

  Further, in a state where the seal surface 33 is in close contact with the inner surface of the mounting hole 201, the seal member 300 can be in close contact with both the end surface of one end of the body portion 1 and the protruding portion 203 of the mounting hole 201 in the elastic deformation region. It is necessary to design the clearance between the end surface of the one end portion of the body portion 1 and the protruding portion 203 of the mounting hole 201.

(Second Embodiment)
FIG. 3 is a schematic cross-sectional view showing a main part of a structure for attaching the pressure sensor 100 to the engine 200 according to the second embodiment of the present invention. FIG. 4 is a diagram showing a planar configuration of the seal member 310 according to this embodiment.

  The seal member 310 of the present embodiment has a ring shape, and has elasticity in the double arrow Y2 direction in FIG. 4, that is, the radial direction Y2. In this example, the seal member 310 is a ring having a C-shaped overall shape with a part cut away. As the material of the seal member 310, a material that can withstand the high heat of the combustion flame and has a spring property is preferable, as in the above embodiment, and a metal such as stainless steel is suitable.

  And the seal member 310 of this example is in the state shown by the broken line in FIG. 4 when the elastic force is not acting, and when the joint 313 of the notch portion is narrower than in the free state. Then, it tries to open outward by the elastic force in the radial direction Y2.

  In this example, as shown in FIG. 3, a ring-shaped groove 21 is formed on the outer surface of the body portion 1 of the pressure sensor 100 on the one end side of the body portion 1 with respect to the seal surface 33 over the entire circumference. The inner peripheral portion 311 (see FIG. 4) of the seal member 310 is fitted in the groove 21.

  Here, two grooves 21 are provided on the outer surface of the metal case 20 in the body portion 1, and two seal members 310 are provided accordingly, but the grooves 21 are formed on the outer surface of the body portion 1. Of these, it may be provided at a position closer to one end portion of the body portion 1 than the seal surface 33, and may be provided at the metal stem 30 or the pressure receiving diaphragm 10. Moreover, the groove | channel 21 and the sealing member 310 may be one, and may be three or more.

  In this example, the inner peripheral portion 311 (see FIG. 4) of the seal member 310 is brought into contact with the body portion 1, and the outer peripheral portion 312 (see FIG. 4) of the seal member 310 is brought into contact with the inner surface of the mounting hole 201. It is in a state.

  In the present mounting structure, the sealing member 310 is brought into such a contact state, so that the sealing member 310 has a notch portion 313 narrower than in the free state as shown in FIG. The seal member 310 is subjected to an elastic force to open in the radial direction Y2.

  As a result, the seal member 310 is in close contact with both the body portion 1 and the inner surface of the mounting hole 201, so that the seal by the elasticity of the seal member 310 is performed. As described above, also in the present embodiment, the seal member 310 that seals the gap 204 between the body portion 1 and the mounting hole 201 is provided on the combustion chamber 202 side of the body portion 1 with respect to the seal surface 33 of the body portion 1. Therefore, the intrusion of the deposit from the combustion chamber 202 as described above can be prevented.

  The mounting structure of the pressure sensor 100 according to this embodiment is such that the pressure sensor 100 is mounted from one end side of the body portion 1 in a state where the seal member 310 is installed in the groove 21 of the body portion 1 of the pressure sensor 100. It is formed by inserting into the hole 201 and screwing it through the screw part 41.

  FIG. 5 is a schematic cross-sectional view showing another example of the present embodiment. The seal member 320 of this example is attached to the outer surface of the pressure receiving diaphragm 10 in the body portion 1. As shown in FIG. 5, the seal member 320 of the present embodiment is a ring having a V-shaped cross section, and even if the elastic force is exerted in the radial direction due to the spread of the V-shape. Good.

  Also in this example, sealing is performed by the elasticity of the seal member 320 in a state where the inner peripheral portion 321 of the seal member 320 is in contact with the body portion 1 and the outer peripheral portion 322 of the seal member 320 is in contact with the inner surface of the mounting hole 201. It has been broken.

(Other embodiments)
In addition, as a sealing member, it is not limited to each above-mentioned sealing member 300,310,320, It mounts | wears with the site | part of the one end part side of the trunk | drum 1 rather than the sealing surface 33 among the outer surfaces of the trunk | drum 1. What is necessary is just to be able to seal between the said site | part and the inner surface of the attachment hole 201 facing this.

  Further, the body portion of the pressure sensor is not limited to the above-described embodiment, and is tubular and has a pressure receiving portion at one end portion thereof, and is inserted into the mounting hole of the engine from the one end portion on the outer surface thereof. What is necessary is just to have a sealing surface as the sealing surface which seals occasionally. Further, the pressure receiving portion is not limited to the pressure receiving diaphragm 10 described above.

It is a schematic sectional drawing which shows the attachment structure of the pressure sensor which concerns on 1st Embodiment of this invention. It is a figure which shows the structure of the sealing member single-piece | unit of the said 1st Embodiment, (a) is a top view, (b) is a partial cross section perspective view. It is a schematic sectional drawing which shows the principal part of the attachment structure of the pressure sensor which concerns on 2nd Embodiment of this invention. It is a figure which shows the planar structure of the sealing member single-piece | unit of the said 2nd Embodiment. It is a schematic sectional drawing which shows the other example of the said 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Body part of pressure sensor, 10 ... Diaphragm for pressure receiving as pressure receiving part, 21 ... Groove,
33 ... Sealing surface, 100 ... Pressure sensor, 200 ... Engine, 201 ... Mounting hole,
202 ... Combustion chamber, 203 ... Projection of mounting hole, 300, 310, 320 ... Seal member,
301... One side surface in a direction orthogonal to the radial direction of the seal member;
302 ... the other surface in the direction orthogonal to the radial direction of the seal member,
311, 321... Inner periphery of the seal member, 312, 322.

Claims (4)

It has a cylindrical body part (1), has a pressure receiving part (10) for receiving pressure at one end part of the body part (1), and has an outer surface of the body part (1) of the body part (1). A pressure sensor (100) having a sealing surface (33) at a portion on the other end side of the one end portion;
A hole provided in the engine (200), which is a hole (201) leading to the combustion chamber (202), is inserted from one end side of the body (1), and the sealing surface (33) is inserted into the hole (201). In the pressure sensor mounting structure in which the pressure in the combustion chamber (202) is received by the pressure receiving portion (10) by closely contacting and sealing the inner surface of the mounting hole (201).
Of the outer surface of the body part (1), the part closer to the one end part of the body part (1) than the seal surface (33) is connected to the part and the inner surface of the mounting hole (201) facing the part. A pressure sensor mounting structure, wherein seal members (300, 310, 320) for sealing the gap are provided. The sealing member (300) has a ring shape having elasticity in a direction perpendicular to the radial direction,
A ring projecting so that a portion of the inner surface of the mounting hole (201) closer to the combustion chamber (202) than one end of the body (1) overlaps with an end surface of one end of the body (1). Shaped protrusion (203),
The seal member (300) is interposed between the protruding portion (203) and an end surface of one end of the body portion (1),
One surface (301) of the seal member (300) in a direction orthogonal to the radial direction is brought into contact with the protruding portion (203), and the other surface (302) is contacted with one end of the body portion (1). The pressure sensor mounting structure according to claim 1, wherein sealing is performed by the elasticity of the seal member (300) in a state of being in contact with the end face. The sealing members (310, 320) are ring-shaped having elasticity in the radial direction,
The inner peripheral portions (311 and 321) of the seal members (310 and 320) are brought into contact with the body portion (1), and the outer peripheral portions (312 and 322) of the seal members (310 and 320) are connected to the mounting holes (201). 2. The pressure sensor mounting structure according to claim 1, wherein sealing is performed by the elasticity of the seal member (310, 320) in a state where the seal member is in contact with the inner surface of the pressure sensor. A ring-shaped groove (21) is provided over the entire circumference of the outer surface of the body part (1) on the one end side of the body part (1) with respect to the sealing surface (33).
The pressure sensor mounting structure according to claim 3, wherein an inner peripheral portion (311) of the seal member (310) is fitted in the groove (21).

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