JP2019174392A - Pressure detection device - Google Patents

Abstract

To provide a pressure detection device with high measurement performance which can suppress an influence on the pressure detection unit caused by heat and pressure received from the pressure medium.SOLUTION: A pressure detection device 5 is attached to a mounting hole 4H of the container containing the pressure medium, detects the pressure of the pressure medium, and includes casings 30, 40a, and 40b that constitute the outer periphery of the pressure detection device 5, a pressure receiving unit 40r that receives pressure of the pressure medium, a pressure detection unit 10 that is provided inside the housing and detects the pressure received by the pressure receiving unit 40r, an attachment portion 31k which is a part of the housing for attaching the pressure detection device 5 to the attachment hole, and a deforming portion 30d that is a part of the housing, is provided at a position different from the pressure receiving portion 40r and deforms toward the attachment portion 31k.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a pressure detection device that is attached to a mounting hole of a container containing a pressure medium and detects the pressure of the pressure medium in the container.

  Conventionally, as one of pressure detection devices that are attached to a mounting hole of a container containing a pressure medium and detect the pressure of the pressure medium in the container, for example, attached to a cylinder head of an internal combustion engine, combustion in a combustion chamber of the internal combustion engine A pressure detection device that measures pressure is known.

  For example, Patent Document 1 discloses the structure of such a pressure detection device. The pressure detection device includes a housing formed in a cylindrical shape, and a diaphragm head at the front end of the housing corresponding to the combustion chamber side of the internal combustion engine. The pressure detection device is located behind the diaphragm head and includes a piezoelectric element inside the housing. Is arranged. The pressure detection unit is connected or supported to the housing directly or indirectly. This pressure detection unit detects the pressure in the combustion chamber acting via the diaphragm head, and the combustion pressure is measured.

  Patent Document 2 discloses a configuration in which a seal member is provided between an outer peripheral surface of a housing of a pressure detection device and a mounting hole that communicates with a combustion chamber provided in an internal combustion engine. The seal member is fitted to the housing by being fitted into an annular groove provided on the outer peripheral surface of the housing of the pressure detecting device, and the combustion gas is prevented from flowing into the gap between the pressure detecting device and the mounting hole of the cylinder head. is doing. The annular groove provided on the outer peripheral surface of the housing includes two side wall surfaces and a bottom surface connecting the two side wall surfaces, and the outer diameter gradually increases toward the center position of the annular groove in the housing axial direction on the bottom surface. The protruding portion that becomes large is formed in an annular shape. By providing the protrusion on the bottom surface of the annular groove, the seal member can be firmly sandwiched between the pressure detection device and the mounting hole of the cylinder head at the protrusion, and the seal between the pressure detection device and the cylinder head can be secured. Can be sure.

Japanese Patent Laid-Open No. 2008-191059 Japanese Patent No. 6054862

  Conventional pressure detection devices transmit pressure acting on a diaphragm head, which is a pressure receiving unit for receiving pressure of a pressure medium, to the pressure detection unit, and measure the pressure of the pressure medium transmitted by the pressure detection unit. In addition, not only the diaphragm head which is the pressure receiving part, but also a part of the housing is exposed to the pressure medium. When the housing is exposed to the pressure medium, the housing expands and contracts due to the pressure and heat received from the pressure medium, and the detection performance of the pressure detection device is received by the pressure detector housed inside the housing. Fluctuates. The fluctuation in detection performance of this pressure detection device is a major problem especially in the measurement of high-pressure and high-temperature pressure media such as the combustion pressure of internal combustion engines, and is designed on the assumption that it will be exposed to the pressure media in advance. It is more likely that not only a part of the pressure detection device that has been used but also a part that was not sufficiently assumed to be exposed to the pressure medium or a part that is susceptible to heat and pressure is exposed to the pressure medium. It is a problem.

  For example, the following problems occur in the pressure detection device described in Patent Document 2. The pressure detection device described in Patent Document 2 is provided with an annular groove in the housing of the pressure detection device and a protrusion on the bottom surface of the annular groove in order to securely seal between the pressure detection device and the cylinder head. . The seal between the pressure detection device and the cylinder head is mainly formed in this protrusion, and the end of the bottom surface of the annular groove in the axial direction of the housing (annular groove) into which the seal member is fitted is the protrusion on the bottom surface of the annular groove. The outer periphery of the annular groove (the outer diameter of the housing) becomes smaller as the distance from the position in the axial direction of the housing decreases. Therefore, the end of the annular groove has a weaker force that the seal member is pressed between the pressure detection device and the cylinder head than the protrusion, and the pressure detection device and the seal member cannot be sufficiently contacted, There may be a gap between the pressure detection device and the seal member.

  Further, since the seal member is press-fitted into the mounting hole when the pressure detecting device is attached to the mounting hole of the cylinder head, the seal member is moved from the front end side of the pressure detecting device due to frictional resistance generated between the seal member and the mounting hole. It may shift to the rear end side.

  Due to the gap formed between the pressure detection device and the seal member, or due to the displacement of the seal member that occurs when the pressure detection device is installed, a part of the housing that would otherwise be covered with the seal member is into the mounting hole that communicates with the combustion chamber. When exposed, the exposed portion is directly exposed to combustion gas having a high temperature and a high pressure. As a result, the exposed portion is distorted by receiving heat and pressure higher than expected, and the distortion of the exposed portion acts as a force transmitted to the pressure detecting portion that is directly or indirectly connected to the housing. Affects the detected value.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a pressure detection device having high measurement performance by suppressing the influence on the pressure detection unit caused by heat and pressure received by the pressure detection device. And

  A pressure detection device that is attached to a mounting hole of a container containing a pressure medium and detects the pressure of the pressure medium, and is provided in a casing that constitutes an outer peripheral portion of the pressure detection device, and a part of the casing A pressure receiving portion that receives the pressure of the pressure medium, a pressure detection portion that is provided inside the housing and detects the pressure received by the pressure receiving portion, and a part of the housing, the pressure A pressure provided with an attachment portion for attaching the detection device to the attachment hole, and a deforming portion which is a part of the housing and is provided at a position different from the pressure receiving portion and which is deformed toward the attachment portion. A detection device is used.

Here, the deforming portion may be deformed by the pressure of the pressure medium.
The casing is a cylindrical body having a cylindrical portion, the pressure receiving portion is provided at one end of the cylindrical portion of the casing, and the deforming portion is disposed around the pressure receiving portion. It is good that it is the protrusion part which protruded from the cylindrical part of the body to radial direction.
Moreover, the said deformation | transformation part has a return shape in the other end side of the said housing | casing, and it is good to bend | bend using the junction part of the said cylindrical part and the said protrusion part as a fulcrum.
The deforming portion may be formed so as to cover a peripheral edge portion of the pressure receiving portion.
Moreover, the heat radiating member is attached to the said housing | casing, and the said deformation | transformation part is good to contact the said heat radiating member by deform | transforming.
Furthermore, the heat radiating member may be a sealing member that seals between the housing and the mounting hole.

  According to the pressure detection device of the present invention, it is possible to suppress the influence on the pressure detection unit caused by heat and pressure received from the pressure medium by the pressure detection device, and it is possible to provide pressure detection with high measurement performance.

1 is a schematic configuration diagram of an internal combustion engine according to Embodiment 1 of the present invention. It is a figure for demonstrating the pressure detection apparatus which concerns on Example 1 of this invention, and the X section enlarged view of FIG. It is a figure for demonstrating the pressure detection apparatus which concerns on Example 1 of this invention, and sectional drawing of the YY part which expanded the Z part of FIG. It is a figure for demonstrating the pressure detection apparatus which concerns on Example 1 of this invention, and is the A section enlarged view of FIG. It is a figure for demonstrating the pressure detection apparatus which concerns on Example 2 of this invention, and sectional drawing to which the front-end | tip part of the pressure detection apparatus was expanded.

  Here, the pressure detection device of the present invention will be described by taking as an example a pressure detection device that is attached to a cylinder head of an internal combustion engine and measures the combustion pressure in the combustion chamber of the internal combustion engine.

  FIG. 1 is a schematic configuration diagram of an internal combustion engine according to Embodiment 1 of the present invention. As shown in FIG. 1, the internal combustion engine 1 includes a cylinder block 2 having a cylinder 2a, a piston 3 that reciprocates in the cylinder 2a, and a combustion chamber C that is fastened to the cylinder block 2 together with the cylinder 2a, the piston 3, and the like. And a cylinder head 4 to be formed. Furthermore, the cylinder head 4 that forms the combustion chamber C is provided with a mounting hole 4H that is formed on the wall surface of the cylinder head 4 that constitutes the combustion chamber C and that connects the combustion chamber C and the outside. The internal combustion engine 1 is mounted in the mounting hole 4H of the cylinder head 4 to detect the pressure in the combustion chamber C, and is interposed between the pressure detection device 5 and the cylinder head 4. Thus, a seal portion composed of a first seal member 71 and a second seal member 72 for maintaining airtightness in the combustion chamber C is provided. In the following description, the center line direction of the substantially cylindrical pressure detection device 5 is simply referred to as an axial direction. Further, the combustion chamber C side in the axial direction of the pressure detection device 5 is the front end side, and the opposite direction is the rear end side of the pressure detection device 5. The first seal member 71 is attached to the front end side of the pressure detection device 5, and the second seal member 72 is attached to the rear end side.

  FIG. 2 is a diagram for explaining the pressure detection device according to the first embodiment of the present invention, and is an enlarged view of a portion X in FIG. 1. As shown in FIG. 2, the mounting holes 4H of the cylinder head 4 are gradually formed from the combustion chamber C side toward the first hole 4a and from the hole diameter of the first hole 4a toward the combustion chamber C opposite to the axial direction. It has the inclination part 4b in which the hole diameter is expanding, and the 2nd hole part 4c whose hole diameter is larger than the hole diameter of the 1st hole part 4a. On the surrounding wall forming the second hole 4c, a female screw 4d into which a male screw 33 of the housing 30 (described later) formed in the pressure detection device 5 is screwed, and a diameter slightly larger than the outermost diameter of the male screw 33 of the housing 30 are provided. Three holes 4e are formed.

  The pressure detection device 5 includes a piezoelectric element 10 (see FIG. 3) that is a pressure detection unit that converts the pressure in the combustion chamber C into an electric signal, and a cylindrical shape that accommodates the piezoelectric element 10 and the like inside the cylinder. And a housing 30 having a hole formed therein. The housing 30 includes a first housing 31 provided on the front end side and a second housing 32 provided on the rear end side. The first housing 31 and the second housing 32 are joined by a joining method such as laser welding.

  A diaphragm head 40 including a pressure receiving portion 40r that is a portion for receiving the pressure of the combustion chamber C and transmitting the pressure to the piezoelectric element 10 that is a pressure detection portion is provided on the end surface on the distal end side of the first housing 31. The pressure received by the pressure receiving portion 40 r of the diaphragm head 40 is transmitted to the piezoelectric element 10 that is a pressure detection portion inside the housing 30. The first housing 31 and the diaphragm head 40 are joined by a joining method such as laser welding.

  The first housing 31 includes a front end side outer peripheral surface 31a and a rear end side outer peripheral surface 31c having a larger outer diameter than the front end side outer peripheral surface 31a, and a connecting portion between the front end side outer peripheral surface 31a and the rear end side outer peripheral surface 31c. Has an inclined surface 31b formed in a tapered shape whose outer diameter gradually increases from the front end side toward the rear end side.

  Further, a stepped portion 31k formed of an annular groove formed over the entire circumferential direction is formed on the distal end side outer peripheral surface 31a. The first seal member 71 is fitted into the step portion 31k.

  The first seal member 71 has a substantially trapezoidal cross section, and the first seal member 71 is sandwiched between the mounting hole 4H of the cylinder head 4 and the stepped portion 31k of the pressure detection device 5, so that the combustion gas detects the pressure. It has a function of preventing leakage to the rear end side of the device 5.

  The second housing 32 has a first outer peripheral surface 32a, a second outer peripheral surface 32b having an outer diameter larger than the outer diameter of the first outer peripheral surface 32a, and an outer diameter of the second outer peripheral surface 32b from the front end side to the rear end side. A third outer peripheral surface 32c having a larger outer diameter and a fourth outer peripheral surface 32d having an outer diameter larger than the outer diameter of the third outer peripheral surface 32c. A male screw 33 that is screwed into the female screw 4d of the cylinder head 4 is formed on the distal end side of the second outer peripheral surface 32b. The fourth outer peripheral surface 32d is formed in a regular hexagonal column shape having six surfaces that are equally spaced in the circumferential direction, and the third outer peripheral surface 32c is interposed between the third outer peripheral surface 32c and the fourth outer peripheral surface 32d. And an end face 32e that connects the fourth outer peripheral face 32d. The fourth outer peripheral surface 32d is a part to which a tightening tool is fitted when the pressure detecting device 5 is attached to and detached from the cylinder head 4, and a rotational force applied to the tool is transmitted. Further, the second seal member 72 is fitted into the rear end side of the third outer peripheral surface 32 c with a gap fit, and when the pressure detection device 5 is attached to the cylinder head 4, the end surface 4 f of the cylinder head 4 and the pressure detection device 5. The second seal member 72 is sandwiched between the end face 32e and the cylinder head 4 and the pressure detection device 5 are sealed.

  The second seal member 72 has an annular shape with a rectangular cross section, and the second seal member 72 is sandwiched between the end surface 4 f of the cylinder head 4 and the end surface 32 e of the pressure detection device 5, so that the combustion gas flows into the combustion engine 1. Has a function to prevent leakage to the outside.

  Here, attachment of the pressure detection device 5 to the cylinder head 4 will be described. The pressure detection device 5 is attached to the cylinder head 4 at three locations: a step portion 31k via the first seal member 71, a male screw 33, and an end face 32e via the second seal member 72. These three locations function as attachment portions for attaching and fixing the pressure detection device 5 to the cylinder head 4 respectively.

  Next, the structure of the distal end portion of the pressure detection device 5 and the seal portion on the distal end side will be described. FIG. 3 is a diagram for explaining the pressure detection device according to the first embodiment of the present invention, and is a cross-sectional view of the YY portion in which the Z portion of FIG. 2 is enlarged. The pressure detection device 5 includes a diaphragm head 40, a piezoelectric element 10 as a pressure detection unit that converts the pressure received by the pressure receiving unit 40r of the diaphragm head 40 into an electric signal, and a cylindrical element inside the piezoelectric element 10 and the like. And a housing 30 in which a cylindrical hole is formed.

  The diaphragm head 40 has a cylindrical tubular portion 40a, a plate-shaped pressure receiving portion 40r that closes the distal end side of the tubular portion 40a, and protrudes from the distal end side of the tubular portion 40a toward the outer periphery of the pressure receiving portion 40r. The flange portion 40b is provided.

  Between the diaphragm head 40 and the piezoelectric element 10, there is provided a first electrode portion 9 that transmits the pressure received by the pressure receiving portion 40 r of the diaphragm head 40 to the piezoelectric element 10 and is electrically connected to the piezoelectric element 10. On the rear end side of the piezoelectric element 10, a second electrode portion 11 that supports the piezoelectric element 10 and is electrically connected to the piezoelectric element 10 is provided.

  The pressure detection device 5 is provided with an insulating ring 12 that electrically insulates the second electrode portion 11 and a pressure applied to the pressure receiving portion 40r of the diaphragm head 40 provided on the rear end side of the insulating ring 12. A support member 13 that is received via a member such as the piezoelectric element 10 that is a portion, and a conductive member 14 that is electrically connected to the second electrode portion 11.

Next, the seal portion on the distal end side of the pressure detection device 5 will be specifically described.
The first seal member 71 has an annular shape with a substantially trapezoidal cross section, and is fitted into and attached to a stepped portion 31k which is a groove on the outer peripheral surface 31a on the front end side of the first housing 31. The front end surface 71f of the first seal member 71 is inclined with respect to the center line of the pressure detection device 5, and has a tapered shape in which the outer diameter gradually increases from the front end side to the rear end side. Yes.

  Next, a specific shape of the stepped portion 31k that is an attachment portion of the first seal member 71 will be described. The step portion 31 k that is an attachment portion of the first seal member 71 is a groove formed over the entire circumferential direction of the first housing 31. A groove bottom surface 31kb, which is the bottom surface of the stepped portion 31k, is formed with a protruding portion 31p having an annular protruding shape over the entire circumferential direction. In the present embodiment, the outer diameter of the annular protrusion 31p formed on the groove bottom surface 31kb of the step portion 31k is smaller than the outer diameter of the distal end side outer peripheral surface 31a.

  Further, the protruding portion 31p is disposed on the distal end side of the pressure detecting device 5 with respect to the axial center position of the groove bottom surface 31kb. Further, the groove bottom surface 31kb has two substantially conical surfaces in which the outer diameter of the first housing 31 gradually decreases from the protrusion 31p toward the front end side and the rear end side of the pressure detection device 5 along the axial direction. The front end side conical surface 31pf is provided with a front end side conical surface 31pf and the rear end side conical surface is provided with a rear end conical surface 31pr.

Furthermore, it is a side wall surface of the step portion 31k, a front end side side wall surface 31kf that connects the front end side conical surface 31pf and the front end side outer peripheral surface 31a, a side wall surface of the step portion 31k, and a rear end side conical surface. The rear end side wall surface 31kr, which is a surface connecting 31pr and the front end side outer peripheral surface 31a, is provided. The angle formed by the connecting portion connecting the tip side wall surface 31kf and the groove bottom surface 31kb is an acute angle, and the angle formed by the connecting portion between the tip side outer peripheral surface 31a and the tip side wall surface 31kf on the tip side from the stepped portion 31k is also an acute angle. It is. Therefore, the part comprised by the front end side outer peripheral surface 31a and the front end side wall surface 31kf on the front end side with respect to the stepped portion 31k has a return shape protruding toward the rear end side with respect to the surface orthogonal to the axial direction. The front end side end surface of the first housing 31 is a surface parallel to a plane orthogonal to the axial direction. The first housing 31 includes a front end side end surface of the first housing 31, a front end side wall surface 31kf of the step portion 31k, and a step portion 31k. A return portion 31d, which is a portion formed by the distal end side outer peripheral surface 31a on the more distal end side, is provided.
The angle formed by the connecting portion connecting the rear end side wall surface 31kr and the groove bottom surface 31kb is an obtuse angle, and the rear end side wall surface 31kr has a tapered shape in which the outer diameter increases from the front end side toward the rear end side. Is formed.

  The first housing 31 and the diaphragm head 40 are connected by connecting the front end side end surface of the first housing 31 and the rear end side end surface of the flange portion 40b of the diaphragm head 40, and the return portion 31d of the first housing 31 and the diaphragm head are connected. A deformed portion 30d is formed in which the flange portion 40b of the head 40 is integrated. The deformed portion 30d is exposed to the combustion gas, which is a pressure medium, with its distal end exposed to the combustion chamber C. When the pressure from the combustion gas is received, the deformed portion 30d faces the step portion 31k, which is the mounting portion of the pressure detection device 5. And deform.

  FIG. 4 is a view for explaining the pressure detection device according to the first embodiment of the present invention, and is an enlarged view of a portion A in FIG. 3. FIG. 4 is a view showing a state where the pressure of the combustion gas acts on the pressure detecting device 5 and the deforming portion 30d is deformed. When the deformation portion 30d receives pressure from the combustion gas, the deformation portion 30d bends toward the stepped portion 31k with a connection portion where the tip side wall surface 31kf and the groove bottom surface 31kb of the first housing 31 are connected as a fulcrum. In the deformed portion 30d thus deformed, the distal end side wall surface 31kf of the stepped portion 31k, which is the rear end side end portion of the deformed portion 30d, comes into contact with the distal end side end surface 71f of the first seal member 71. The front end side wall surface 31kf and the front end side end surface 71f are in contact with each other so that a part of the front end side wall surface 31kf and a part of the front end side end surface 71f are in line contact over the outer periphery of the cylindrical pressure detection device 5. ing.

In the state where the pressure detection device 5 is attached to the attachment hole 4H of the cylinder head 4, the step portion 31k is not completely covered by the first seal member 71, and an exposed portion exposed to the combustion gas may be formed. The deformed portion 30d receives pressure and deforms to prevent the exposed portion from being directly exposed to the combustion gas. The reason why the exposed portion is formed is that the first due to the frictional resistance between the first hole portion 4a and the first seal member 71 when the pressure detecting device 5 is inserted into the first hole portion 4a of the mounting hole 4H by press fitting or the like. The displacement and deformation of the seal member 71, the dimensional tolerance of at least one of the step portion 31k and the first seal member 71, and the like can be considered. As the exposed portion in the pressure detection device 5 of this embodiment, for example, the tip side of the step portion 31k A part of the conical surface 31pf and the tip side wall surface 31kf may be mentioned. The exposed portion thus formed is a portion that should originally be covered with the first seal member 71, and therefore is not assumed to receive heat or pressure directly from the combustion gas. Since the tip end side conical surface 31pf is a thin portion of the first housing 31, it has a small heat capacity and rigidity, and is a part that is greatly influenced by external heat and external force. In the present embodiment, the deformed portion 30d is deformed toward the stepped portion 31k that is the mounting portion of the pressure detecting device 5 by receiving the pressure of the combustion gas, and the deformed portion 30d contacts the first seal member 71 so that the exposed portion is It was set as the structure which is not directly exposed to combustion gas. Thereby, the pressure detection apparatus 5 can suppress the distortion which arises when the said exposed part receives the heat and pressure of combustion gas, and a measurement performance becomes high.

  In addition, although the deformation | transformation part 30d and the 1st seal member 71 are demonstrated as a structure contact | abutted over the outer periphery of the pressure detection apparatus 5 in a present Example, the deformation | transformation part 30d has the 1st seal member 71 partially. It is good also as a structure which adjoins without contacting or contact | abutting. Even if the deformed portion 30d is in contact with the first seal member 71 and the exposed portion is not directly exposed to the combustion gas, the deformable portion 30d is deformed toward the mounting portion, so that the deformed portion 30d is combusted with the combustion gas. Since it functions as a barrier to heat and pressure transmitted to the part (for example, the exposed portion of this embodiment) that is easily affected by pressure and heat of the (pressure medium), it is easily affected by pressure and heat. The distortion of the part can be suppressed.

  In the present embodiment, the deformable portion 30d and the first seal member 71 are in line contact over the outer periphery of the pressure detection device 5. However, the deformable portion 30d and the first seal member 71 are in pressure contact with each other. It is good also as a structure which carries out surface contact over the outer periphery. When the deformable portion 30d and the first seal member 71 are in surface contact, the heat received by the deformable portion 30d can be efficiently released to the cylinder head 4 by the first seal member 71, and when the deformed portion 30d is in line contact, the deformable portion 30d. In addition, the deformable portion 30d can be reliably brought into contact with the first seal member 71 regardless of the surface roughness of the first seal member 71 or the like.

  Further, in this embodiment, the example in which the protrusion 31p is provided on the groove bottom surface 31kb of the stepped portion 31k has been described. However, the present invention is not limited to this, and the groove bottom surface 31kb of the stepped portion 31k is not provided with the protrusion 31p. May be a cylindrical shape that is uniform in the axial direction.

  Further, when the deforming portion 30d receives pressure from the combustion gas, the deforming portion 30d is configured to bend toward the stepped portion 31k with the connecting portion connecting the tip side wall surface 31kf and the groove bottom surface 31kb of the first housing 31 as a fulcrum. As long as the structure is deformed toward the attachment part, for example, the deformation part 30d itself may be bent and deformed. In addition, the shape of the deformable portion 30d is not limited to the present embodiment. For example, the tip side wall surface 31kf constituting the deformable portion 30d is a curved surface (bow shape) having a single or a plurality of curvature radii. It may be a stepped shape having a step. Furthermore, the tip side wall surface 31kf may be formed by a plane perpendicular to the axial direction from the groove bottom surface 31kb.

  Furthermore, although the present embodiment is configured to include one deformation portion 30d, a plurality of deformation portions corresponding to the deformation portion 30d may exist. Moreover, the deformation | transformation part 30d is not only the structure which deform | transforms toward the level | step-difference part 31k, The site | part between the deformation | transformation part 30d and the attachment part should just be protected from the influence of a heat | fever or a pressure by the deformation | transformation part 30d. Or the end face 32e, and the deformation part 30d may be provided on the tip side of the attachment part.

  FIG. 5 is a view for explaining the pressure detection device according to the second embodiment of the present invention, and is an enlarged cross-sectional view of the tip portion of the pressure detection device. The pressure detection device according to the second embodiment is a modification of the pressure detection device 5 according to the first embodiment, and the description of the same members as those of the pressure detection device 5 described in the first embodiment is omitted, and the same reference numerals are used. It explains using.

  The pressure detection device 50 according to the second embodiment of the present invention is different from the pressure detection device 5 according to the first embodiment in the tip side portion of the pressure detection device 5. Specifically, the outer diameter of the outer peripheral surface 31a on the distal end side from the stepped portion 31k of the diaphragm head 40 and the first housing 31 is smaller, and the outer periphery on the distal end side from the stepped portion 31k of the first housing 31 to the distal end side. An L-shaped annular member 32L is mounted on the surface 31a. The L-shaped annular portion 32L has an inner diameter slightly larger than the tip end outer peripheral surface 31a on the tip end side from the step portion 31k of the first housing 31, and is welded to the tip end outer peripheral surface 31a on the tip end side from the step portion 31k. The portion 32LP includes a deformed portion 32f having a thin annular shape on the surface orthogonal to the axial direction from the tip of the tubular portion 32LP and extending toward the central axis of the tubular portion 32LP. The L-shaped annular member 32L is attached to the first housing 31 so as to have a slight gap between the L-shaped annular member 32L and the deformable portion 32f is formed so as not to cover the pressure receiving portion 40r of the diaphragm head 40. Has been. The rear end side of the L-shaped annular member 32L is formed so as to be flush with the front end side wall surface 31kf of the stepped portion 31k when mounted on the first housing 31.

  The pressure detection device 50 according to the second embodiment of the present invention includes the deformable portion 30d as in the first embodiment, and includes the deformable portion 32f as another deformable portion. When the deformation portion 32f receives pressure from the combustion gas, the deformation portion 32f bends toward the stepped portion 31k, which is one of the attachment portions, with the connection portion between the cylindrical portion 32LP and the deformation portion 32f as a fulcrum. This deformation is elastic deformation. By deforming the deforming portion 32f toward the mounting portion, it is possible to suppress or prevent the influence of heat and pressure from the combustion gas on the flange portion 40b of the diaphragm head 40. Therefore, the measurement performance of the pressure detection device 50 can be further improved.

  Here, the deforming portion 32f is elastically deformed by the pressure from the combustion gas, but is not limited to elastic deformation, and it is obvious that the effect of the present invention can be obtained even when the deforming portion is plastically deformed.

  As described above, the pressure detection device of the present invention has been described based on the embodiments. However, the pressure detection device is not limited to the pressure devices described in the embodiments, and includes a deformation portion and an attachment portion. Any form may be used as long as it is possible to prevent a problem with the pressure detection device caused by heat or pressure from the pressure medium by deforming.

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 2a Cylinder 2 Cylinder block 3 Piston 4 Cylinder head 4H Mounting hole 4a 1st hole part 4b Inclined part 4c 2nd hole part 4d Female screw 4e 3rd hole part 4f End surface 5 Pressure detection device 9 1st electrode part 10 Piezoelectric element 11 Second electrode portion 12 Insulating ring 13 Support member 14 Conductive member 30 Housing 30d Deformed portion 31 First housing 31a Front end side outer peripheral surface 31b Inclined surface 31c Rear end side outer peripheral surface 31k Stepped portion 31kb Groove bottom surface 31p Projection portion 31pf Front end side cone Surface 31pr Rear end side conical surface 31kf Front end side wall surface 31kr Rear end side wall surface 31d Return portion 32 Second housing 32a First outer peripheral surface 32b Second outer peripheral surface 32c Third outer peripheral surface 32d Fourth outer peripheral surface 32e End surface 32f Deformed portion 32L L-shaped annular member 32LP cylindrical portion 33 male screw 40 diaphragm head 40a cylinder Shaped part 40b flange part 40r pressure receiving part 50 pressure detecting device 71 first seal member 71f front end side end surface 72 second seal member C combustion chamber

Claims (7)

A pressure detection device that is attached to a mounting hole of a container containing a pressure medium and detects the pressure of the pressure medium,
A housing constituting the outer periphery of the pressure detection device;
A pressure receiving portion that is provided in a part of the housing and receives the pressure of the pressure medium;
A pressure detection unit that is provided inside the housing and detects the pressure received by the pressure receiving unit;
A part of the housing, and an attachment part for attaching the pressure detection device to the attachment hole;
A deformation part that is a part of the housing, is provided at a position different from the pressure receiving part, and is deformed toward the attachment part;
A pressure detection device comprising:   The pressure detecting device according to claim 1, wherein the deforming portion is deformed by a pressure of the pressure medium. The housing is a tubular body having a tubular portion,
The pressure receiving portion is provided at one end of the cylindrical portion of the housing,
The pressure detecting device according to claim 2, wherein the deforming portion is a protruding portion that is disposed around the pressure receiving portion and protrudes in a radial direction from a cylindrical portion of the housing.   The pressure detecting device according to claim 3, wherein the deforming portion has a return shape on the other end side of the housing and bends with a joint portion of the cylindrical portion and the protruding portion as a fulcrum.   The pressure detecting device according to claim 1, wherein the deforming portion is formed so as to cover a peripheral portion of the pressure receiving portion. A heat dissipation member is attached to the housing,
The pressure detecting device according to claim 1, wherein the deforming portion is deformed to come into contact with the heat radiating member.   The pressure detection device according to claim 6, wherein the heat radiating member is a seal member that seals between the housing and the mounting hole.

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