JP2017181469A - Functional component, and removal method of functional component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a functional component 5 capable of extracting a seal member 72 without leaving the seal member 72 in an attachment hole 4a when the functional component is removed from the attachment hole 4a of a cylinder head 4 and without damaging the inside of the attachment hole 4a even when it is left in the attachment hole 4a, and provide a removal method of the functional component.SOLUTION: A functional component 5 includes a housing 30 capable of being inserted into an attachment hole 4a. A step portion 31bt as a first lock portion for locking a seal member 72 is disposed on an outside surface of the housing 30. On the outside surface of the housing 30, a step portion 315at as a second lock portion for locking the seal member 72 is disposed at a position other than that of the step portion 31bt along the attachment axial direction.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a functional component for an internal combustion engine that can be inserted into a mounting hole that communicates with a combustion chamber of the internal combustion engine, and a method for removing the functional component.

  Conventionally, functional parts including a housing that can be inserted into a mounting hole provided in a cylinder head of an internal combustion engine, such as a fuel injection device, a spark plug, and a glow plug, are generally known. In recent years, a pressure detection device that detects a pressure acting on a combustion chamber of an internal combustion engine is also one of functional components.

  The above-mentioned functional parts are provided with a columnar housing, and are used by being inserted into a mounting hole of a cylinder head where the combustion chamber of the internal combustion engine communicates with the outside. As a pressure detection device exemplified as one of such functional components, for example, Patent Document 1 discloses the structure thereof. The pressure detection device includes a cylindrical housing and a diaphragm head at the front end of the housing on the combustion chamber side of the internal combustion engine, and a detection unit made of a piezoelectric element is disposed behind the diaphragm head and inside the housing. Has been. The detection unit detects the pressure in the combustion chamber acting via the diaphragm head, and the combustion pressure is measured. The pressure detection device is attached and functions along an attachment hole provided in the cylinder head.

  Moreover, in the cited document 2, the structure provided with the two sealing members which seal between the outer surface of the housing of a pressure detection apparatus and the attachment hole which is provided in an internal combustion engine and the exterior communicates is disclosed. The seal member disposed on the combustion chamber side of the seal member is locked to the step portion by being fitted into the step portion formed by a groove provided on the outer surface of the housing, and the pressure detection device and the mounting hole of the cylinder head are Combustion gas is prevented from flowing into the gaps between them.

Japanese Patent Laid-Open No. 2008-191059 JP 2013-194573 A

  The functional parts used for mounting on the cylinder head of the internal combustion engine are not limited to the pressure detection device, and include a seal member between the functional part and the cylinder head, and this seal member provides a gap between the functional part and the mounting hole. The inflow of combustion gas is suppressed. The seal member disposed between the functional component and the cylinder head may remain in the mounting hole without being taken out simultaneously with the functional component when the functional component is removed.

  In particular, in the pressure detection device exemplified as one of the functional parts, a seal member is disposed in the vicinity of the combustion chamber. Therefore, deposits are accumulated around the seal member, and the mounting hole and the seal member are easily fixed. . Therefore, for example, even if a step portion for locking the seal member is provided in the housing portion of the functional component, the seal member cannot be sufficiently locked when the functional component is removed. The seal member often comes off from the part.

  In order to take out the seal member left in the mounting hole, it is necessary to perform a complicated take-out operation using a special tool or jig for taking out the seal member. A particularly problematic point is that the inner surface of the mounting hole is damaged during the removal operation, and further, the sealing surface on the inner surface side of the mounting hole with which the seal member is in contact is damaged. In such a case, it is not possible to sufficiently maintain the sealing performance between the newly installed functional component, the sealing material, and the mounting hole, which may lead to combustion gas leakage.

  The present invention has been made in view of the above problems, and when removing a functional component from the mounting hole of the cylinder head, the sealing member is not left in the mounting hole or is attached even if it remains in the mounting hole. It is an object of the present invention to provide a functional component capable of taking out a seal member without damaging the inside of the hole and a method for removing the functional component.

(1) According to one aspect of the present invention,
A functional component attached to a mounting hole that communicates with a combustion chamber of an internal combustion engine, the functional component including a housing that can be inserted into the mounting hole, and a seal member that seals between the mounting hole and an outer surface of the housing. A first locking portion for stopping is provided on an outer surface of the housing, and a second locking portion different from the first locking portion for locking the seal member is provided on the outer surface of the housing. It shall be a functional component.

(2) The second locking portion is a functional component having a locking force of the seal member larger than that of the first locking portion.

(3) The first locking part and the second locking part are functional parts provided at least partially continuously.

(4) When the functional component is attached to the internal combustion engine, when the functional chamber side of the functional component is the front end side and the direction opposite to the front end side is the rear end side, the second locking portion is the first It is assumed that the functional component is provided on the tip side from the one locking portion.

(5) The second locking portion is a functional component provided on the rear end side from the first locking portion.

(6) A plurality of the second locking portions are provided as functional parts.

(7) The second locking portion is a functional component provided on the front end side and the rear end side across the first locking portion.

(8) The second locking portion is a functional component including a stepped portion.

(9) The second locking portion is a functional component having a surface rougher than the outer side surface of the housing excluding the second locking portion.

(10) A method of removing a functional component attached to a mounting hole that communicates with a combustion chamber of an internal combustion engine, wherein the functional component is a housing that can be inserted into the mounting hole, and between the mounting hole and an outer surface of the housing. A first locking portion for locking a seal member for sealing the seal member and a second locking portion different from the first locking portion for locking the seal member are provided on the outer surface of the housing, The sealing member is locked to the second locking part, and the functional component and the sealing member are removed from the mounting hole.

(11) When the functional component is attached to the internal combustion engine, when the functional chamber side of the functional component is the front end side and the direction opposite to the front end side is the rear end side, the second locking portion is the first A functional component that is provided on the front end side from one locking portion, and when the functional component is pulled out to the rear end side, the sealing member is locked to the second locking portion, and the functional component is removed from the mounting hole. The removal method.

(12) When the functional component is attached to the internal combustion engine, the second locking portion is the first locking portion when the combustion chamber side of the functional component is the front end side and the direction opposite to the front end side is the rear end side. It is provided on the rear end side from one locking portion, and the functional component is pushed to the front end side to lock the seal member on the second locking portion, and then the functional component is pulled out to the rear end side. Thus, the functional component is removed from the mounting hole.

  According to the present invention, apart from the first locking portion for locking the seal member, the second locking portion for locking the seal member detached from the first locking portion is provided on the outer surface of the functional component. As a result, the seal member can be taken out without leaving it in the mounting hole of the cylinder head, or can be easily taken out without damaging the mounting hole.

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 II 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 IV-IV part which expanded the V part of FIG. It is a figure for demonstrating the pressure detection apparatus concerning Example 2 of this invention, and is an enlarged view of the front-end | tip part of the pressure detection apparatus with which the cylinder head was mounted | worn. It is a figure for demonstrating the pressure detection apparatus which concerns on Example 3 of this invention, and is an enlarged view of the pressure detection apparatus front-end | tip part with which the cylinder head was mounted | worn. It is a figure for demonstrating the pressure detection apparatus which concerns on Example 4 of this invention, and is an enlarged view of the pressure detection apparatus front-end | tip part with which the cylinder head was mounted | worn. The figure for demonstrating the removal method of a pressure detection apparatus in case there exists a 2nd latching | locking part in a rear-end side. The figure for demonstrating the removal method of a pressure detection apparatus in case a 2nd latching | locking part exists in the front end side.

Here, a pressure detection device is taken as an example of the functional component, and the functional component and the method for removing the functional component of the present invention will be described with reference to the drawings.
Example 1
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. Further, the cylinder head 4 forming the combustion chamber C is provided with a mounting hole 4a formed on the wall surface of the cylinder head 4 constituting the combustion chamber and communicating the combustion chamber C with the outside. The internal combustion engine 1 is mounted in the mounting hole 4 a of the cylinder head 4 to detect a pressure in the combustion chamber C and is interposed between the pressure detection device 5 and the cylinder head 4. And a sealing portion for maintaining the airtightness in the combustion chamber C. Hereinafter, the center line direction of the substantially cylindrical pressure detection device 5 is simply referred to as a center line direction. In the following description, the combustion chamber C side 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 seal portion includes a first seal member 71 attached to the rear end side of the pressure detection device 5 and a second seal member 72 attached to the front 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 II in FIG. 1. 2, the mounting hole 4a of the cylinder head 4 includes, from the combustion chamber C side, a first hole part 4b, and an inclined part 4c whose diameter gradually increases from the hole diameter of the first hole part 4b, A second hole portion 4d having a hole diameter larger than that of the first hole portion 4b. A female screw 4e into which a male screw 332a of the housing 30 (described later) formed in the pressure detection device 5 is screwed is formed on the surrounding wall forming the second hole 4d.

  The pressure detection device 5 includes a piezoelectric element (not shown) that converts the pressure in the combustion chamber C into an electrical signal, and a cylindrical housing 30 in which a cylindrical hole that accommodates the piezoelectric element and the like is formed. And. 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.

  A diaphragm head 40 for receiving the pressure in the combustion chamber C is provided on the end surface on the front end side of the first housing 31. The pressure received by the diaphragm head 40 is transmitted to the piezoelectric element inside the housing 30. The first housing 31 and the diaphragm head 40 are joined by a joining method such as laser welding over the entire circumferential direction.

  The first housing 31 includes a front end side surface 31b and a rear end side surface 315 having an outer diameter larger than that of the front end side surface 31b. The connection portion between the front end side surface 31b and the rear end side surface 315 includes a front end side. The inclined surface 315a as an example of the shoulder part formed in the taper shape from which an outer diameter becomes large gradually toward the rear end side.

  Further, on the inclined surface 315a side of the tip side surface 31b, a step portion 31bt made of a groove formed over the entire circumferential direction is formed. The second seal member 72 is fitted into the step portion 31bt. The step portion 31bt functions as a first locking portion that locks the second seal member 72 to the first housing.

  Furthermore, a stepped portion 315at made of a groove formed over the entire circumferential direction is formed on the inclined surface of the first housing 31. The step portion 315at functions as, for example, a second locking portion that locks and takes out the second seal member 72 detached from the step portion 31bt when the pressure detection device 5 is removed from the mounting hole 4a.

  The outer peripheral surface 330 of the second housing 32 includes a first outer peripheral surface 331, a second outer peripheral surface 332 having an outer diameter larger than the outer diameter of the first outer peripheral surface 331, and a second outer peripheral surface from the front end side to the rear end side. The third outer peripheral surface 333 has an outer diameter larger than the outer diameter of 332, and the fourth outer peripheral surface 334 has an outer diameter larger than the outer diameter of the third outer peripheral surface 333. A male screw 332 a that is screwed into the female screw 4 e of the cylinder head 4 is formed at the tip of the second outer peripheral surface 332. The first seal member 71 is fitted into the third outer peripheral surface 333 with a clearance fit. The rear end portion of the fourth outer peripheral surface 334 is formed as a regular hexagonal column having six chamfers at equal intervals in the circumferential direction. This part is a part into which a tightening tool is fitted and the rotational force applied to the tool is transmitted when the pressure detecting device 5 is attached to and detached from the cylinder head 4.

  In the state where the pressure detecting device 5 is inserted into the mounting hole 4a of the cylinder head 4, the female screw 4e of the mounting hole 4a and the male screw 332a are screwed together, and the inclined portion 4c of the mounting hole 4a and the inclined portion 315a of the first housing 31 are engaged. A second seal member 72 is sandwiched between them, and an end surface 4f in the tightening direction of the pressure detection device 5 on the surrounding wall forming the mounting hole 4a and a fourth outer peripheral surface 334 of the housing 30 of the pressure detection device 5 are provided. The first seal member 71 is sandwiched between the end surface 334a on the distal end side of the formed cylindrical portion, and the cylinder head 4 and the pressure detection device 5 are sealed to be mounted in the mounting hole 4a.

  The first seal member 71 has a ring shape with a rectangular cross section, and the first seal member 71 is sandwiched between the end surface 4f of the cylinder head 4 and the end surface 334a of the pressure detection device 5, whereby the combustion gas is burned into the combustion engine. 1 has a function of preventing leakage to the outside. The first seal member 71 has a function of determining a position in the central axis direction when the pressure detection device 5 is mounted in the mounting hole 4a.

  Below, the internal structure and seal part of the pressure detection apparatus 5 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 IV-IV part in which the V part of FIG. 2 is enlarged. As shown in FIG. 3, the pressure detection device 5 is formed with a piezoelectric element 10 that converts received pressure into an electrical signal, and a cylindrical hole that is cylindrical and that accommodates the piezoelectric element 10 and the like therein. And a housing 30. The pressure detection device 5 is provided so as to close the opening on the front end side of the housing 30, and is provided between the diaphragm head 40 on which the pressure in the combustion chamber C acts, and between the diaphragm head 40 and the piezoelectric element 10. A first electrode unit 50 and a second electrode unit 55 disposed on the opposite side of the piezoelectric element 10 from the first electrode unit 50 are provided.

  In addition, the pressure detection device 5 is provided on the rear end side of the insulating ring 60 that electrically insulates the second electrode portion 55 and the insulating ring 60, and the pressure acting on the diaphragm is passed through a member such as a piezoelectric element. A supporting member 65 for receiving, a conductive member 22 electrically connected to the second electrode portion 55, a covering member 23 for electrically insulating the conductive member 22 through the housing 30 and supporting the conductive member 22; It is equipped with.

    Next, the seal portion on the tip side of the pressure detection device 5 will be specifically described. The second seal member 72 has a substantially C-shaped ring shape with an opening on the inside, and is fitted into a step portion 31bt which is a groove on the outer peripheral surface 31b on the tip side. The inner diameter of the second seal member 72 is set to be slightly smaller than the outer shape of the side surface 31b of the first housing of the pressure detection device 5 (in this embodiment, the outer diameter of the step portion 31bt) before being attached. ing. Therefore, the second seal member 72 is not easily displaced during the operation of the internal combustion engine 1, and the workability when the pressure detection device 5 is attached to and detached from the attachment hole 4 a of the cylinder head 4 is improved. The second seal member 72 is disposed in a space H formed between the inclined surface 315a and the side surface 31b of the pressure detection device 5 and the inclined portion 4c of the cylinder head 4 and the inner wall of the second hole portion 4d. By being sandwiched between the inclined portion 4 c and the inclined portion 315 a, the combustion gas is prevented from flowing into the gap between the pressure detection device 5 and the cylinder head 4 on the rear end side from the second seal member 72.

  Next, specific shapes of the step portion 31bt which is the first locking portion of the second seal member 72 and the step portion 315at which is the second locking portion will be described. The step portion 31bt which is the first locking portion is a groove formed over the entire circumferential direction of the first housing 31, and the groove cross section is rectangular. Further, the step portion 315at, which is the second locking portion, is a groove formed over the entire area in the circumferential direction of the inclined surface 315a of the first housing 31, and the groove cross section is trapezoidal. The groove width of the step portion 315at is the same as the groove width of the step portion 31bt, and the minimum groove depth of the step portion 315at is deeper than the groove depth of the step portion 31bt. Furthermore, the diameter of the first housing 31 at the groove bottom surface of the step portion 315at is larger than the diameter of the first housing 31 at the groove bottom surface of the step portion 31bt.

  Here, the locking force when the second seal member 72 is locked to the step portion 31bt and the step portion 315at will be compared. The step portion 315at has a deeper groove depth than the step portion 31bt, so that when the force in the central axis direction is applied to the second seal member 72, the second seal member 72 is easily caught on the step. 2 The force to stop the seal member 72 in the groove is large.

  Since the step portion 315at has a larger groove bottom diameter than the step portion 31bt, when the second seal member 72 is locked to the step portion 315at, the inner diameter of the second seal member 72 should be increased. Therefore, a radial restraining force that is a reaction force of the force is generated. In this way, the step portion 315at has a large force to stop the second seal member 72 in the groove by the binding force even when a force in the central axis direction is applied to the second seal member 72. From the above, the second locking portion has a higher locking force with respect to the second seal member 72 than the first locking portion. In addition, although the step part 315at in the present embodiment has been described as a trapezoidal groove, it is not limited to this shape. For example, even if the cross section of the groove is U-shaped, V-shaped, or a convex shape instead of a groove, any shape that can lock the second seal member 72 may be used.

(Example 2)
FIG. 4 is a diagram for explaining the pressure detection device according to the second embodiment of the present invention, and is an enlarged view of a tip portion of the pressure detection device mounted on the cylinder head. In addition, about the structure similar to the front end side seal part of the pressure detection apparatus 5 concerning Example 1, the same code | symbol is attached | subjected and the description is abbreviate | omitted. Further, the mounting hole 4a of the cylinder head 4 of the second embodiment has the same structure as the mounting hole 4a described in the first embodiment.

  A configuration related to the pressure detection device 5 mounted in the mounting hole 4a of the cylinder head 4 will be described with reference to FIG. The pressure detection device 5 includes a cylindrical housing 30 that houses a piezoelectric element 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.

  A diaphragm head 40 for receiving the pressure of the combustion chamber C is provided on the end surface on the front end side of the first housing 31.

  The first housing 31 includes a front end side surface 31b and a rear end side surface 315 having an outer diameter larger than that of the front end side surface 31b. The connection portion between the front end side surface 31b and the rear end side surface 315 includes a front end side. The inclined surface 315a as an example of the shoulder part formed in the taper shape from which an outer diameter becomes large gradually toward the rear end side.

  Further, on the inclined surface 315a side of the tip side surface 31b, a step portion 31bt made of a groove formed over the entire circumferential direction is formed. The second seal member 72 is fitted into the step portion 31bt. The step portion 31bt functions as a first locking portion for locking the second seal member 72 to the first housing.

  Furthermore, on the side of the first housing 31 and on the tip side of the stepped portion 31bt, two stepped portions 31ct and 31dt formed of grooves formed over the entire circumferential direction are formed. The step portions 31ct and 31dt function as a second locking portion that locks and takes out the second seal member 72 detached from the step portion 31bt when, for example, the pressure detection device 5 is removed from the mounting hole 4a.

  By providing the second locking portion on the distal end side, it is possible to lock the detached second seal member 72 at the same time as removing the pressure detection device 5. Furthermore, by providing the two step portions 31ct and 31dt, even if the second seal member 72 cannot be locked by one step portion, it can be locked by the other step portion, and the first step portion can be more reliably secured. 2 The seal member 72 can be taken out. Here, in the present embodiment, the second locking portion has been described as two examples. However, the present invention is not limited to this, and the number of the second locking portions may be three or more.

  Next, specific shapes of the stepped portion 31bt that is the first locking portion and the stepped portions 31ct and 31dt that are the second locking portions will be described. The step portion 31bt which is the first locking portion is a groove formed over the entire circumferential direction of the first housing 31, and the groove cross section is rectangular. Further, the step portions 31ct and 31dt, which are the second locking portions, are grooves formed over the entire area in the circumferential direction of the first housing 31, and the groove cross section is rectangular. The groove widths of the step portions 31ct and 31dt are the same as the groove width of the step portion 31bt. The groove depth of the step portion 31ct is shallower than the groove depth of the step portion 31bt, and the diameter of the first housing 31 at the groove bottom surface is larger than the diameter of the first housing 31 at the groove bottom surface of the step portion 31bt. On the other hand, the groove depth of 31 dt is deeper than the groove depth of stepped portion 31bt, and the diameter of first housing 31 at the groove bottom surface is smaller than the diameter of first housing 31 at the groove bottom surface of stepped portion 31bt.

  The difference in the groove depths of the stepped portions 31ct and 31dt as the second locking portions is adapted to the state of the second seal member 72 when the stepped portions 31bt as the first locking portions have come off. It is. It is presumed that the state of the second seal member 72 is different in the mounting hole 4a depending on the usage situation. By setting the second locking portion as two types of stepped portions 31ct and 31bt, even if the second seal member 72 cannot be locked by one stepped portion, it can be locked by the other stepped portion. I am doing so. By setting it as such a structure, the 2nd seal member 72 can be taken out more reliably.

Example 3
The third embodiment is a modification of the second locking portion in the first embodiment. FIG. 5 is a diagram for explaining the pressure detection device according to the third embodiment of the present invention, and is an enlarged view of the front end portion of the pressure detection device 5 attached to the cylinder head 4. In the first embodiment, the step portion 31bt which is the first locking portion is a groove formed over the entire area in the circumferential direction of the first housing 31, and the groove cross section is rectangular. The first stepped portion 31bt is connected to the outer side surface 315 of the first housing 31 with the groove side surface on the rear end side as an inclined surface 315c. The inclined surface 315c surface is provided with a rough surface that is rougher than the surface roughness of the groove bottom surface of the first locking portion over the entire circumferential direction, and is continuous with the step portion 31bt that is the first locking portion. The provided inclined surface 315c is the second locking portion in the present embodiment. Since the second locking portion in this embodiment is an inclined surface 315c whose outer diameter gradually increases from the groove bottom surface of the first locking portion, the radial restraining force acting on the second seal member 72 is the first. It is larger than one locking part. Moreover, since the inclined surface 315c which is a 2nd latching | locking part is a rough surface, friction resistance is larger than a 1st latching | locking part. Therefore, the 2nd latching | locking part becomes a structure where the latching force with respect to the 2nd seal member 72 is larger than the 1st latching | locking part. In addition, although the cross section of the inclined surface 315c in a present Example was demonstrated as a linear shape, it is not limited to this shape. For example, even if the cross section has a convex curve shape, a concave curve shape, a wavy uneven curve shape, or the like, any shape that can lock the second seal member 72 may be used.

Example 4
The fourth embodiment is a modification of the second locking portion in the second embodiment having the second locking portion provided on the distal end side with respect to the first locking portion. FIG. 6 is a view for explaining the pressure detection device 5 according to the fourth embodiment of the present invention, and is an enlarged view of a tip portion of the pressure detection device 5 attached to the cylinder head. In Example 2, the step portions 31ct and 31dt, which are the second locking portions, are grooves formed over the entire area in the circumferential direction, and their groove cross sections are rectangular. On the other hand, the 2nd latching | locking part in a present Example is the level | step-difference part 31et which is intermittently arrange | positioned over the circumferential direction and is a some protrusion. The cross section of the step portion 31et is rectangular. In the present embodiment, the second locking portion is the step portion 31et whose outer diameter is larger than the groove bottom surface of the step portion 31bt which is the first locking portion, and therefore the second seal separated from the first locking portion. The member 72 can be effectively locked.

  Next, the method for removing the functional component of the present invention will be described in detail by taking as an example the removal of the pressure detection device of the first and fourth embodiments.

  First, a method for removing the pressure detection device 5 when the pressure detection device 5 of the first embodiment is used and the second locking portion is provided on the rear end side will be described. FIG. 7 is a view for explaining a method of detaching the pressure detection device 5 when the second locking portion is on the rear end side. The pressure detection device 5 is removed in the next step.

[Step 0]
In this state, the pressure detection device 5 is mounted in the mounting hole 4 a of the cylinder head 4. The second seal member 72 is fitted into the step portion 31bt which is the first locking portion.
[Step 1]
The pressure detection device 5 is pulled out to the rear end side. At this time, the second seal member 72 may come off from the step portion 31bt which is the first locking portion, and may remain in the mounting hole 4a.
[Step2]
The pressure detection device 5 is pushed into the mounting hole 4a, and the second seal member 72 is locked to the step portion 315at that is the second locking portion. If the locking force of the second locking part is made larger than that of the first locking part, the second seal member 72 can be effectively locked to the second locking part.
[Step3]
The pressure detection device 5 is pulled out to the rear end side and removed. At this time, the second seal member 72 is locked and taken out by the step portion 315at which is the second locking portion. If the locking force of the second locking portion is larger than that of the first locking portion, the second seal member 72 can be reliably removed without leaving it in the mounting hole. Even if the second seal member 72 cannot be removed at once, it can be taken out by repeating Step 1 to Step 3.

  Next, a method for removing the pressure detection device 5 in the case where the pressure detection device 5 of the fourth embodiment is used and the second locking portion is provided on the distal end side will be described. FIG. 8 is a view for explaining a method of detaching the pressure detection device 5 when the second locking portion is on the tip side. The pressure detection device 5 is removed in the next step.

[Step 0]
In this state, the pressure detection device 5 is mounted in the mounting hole 4 a of the cylinder head 4. The second seal member 72 is fitted into the step portion 31bt which is the first locking portion.
[Step 1]
The pressure detection device 5 is pulled out to the rear end side. At this time, the second seal member 72 may come off from the stepped portion 31bt which is the first locking portion.
[Step2]
The pressure detection device 5 is continuously pulled out from Step 1, and the second seal member 72 is locked to the step portion 31et that is the second locking portion. If the locking force of the second locking part is made larger than that of the first locking part, the second seal member 72 can be effectively locked to the second locking part.
[Step3]
The pressure detection device 5 is completely pulled out from the mounting hole 4a on the rear end side and removed. At this time, the second seal member 72 is locked and taken out by the step portion 31et which is the second locking portion.

  By removing the pressure detection device 5 by one of the above two steps, the second seal member 72 can be easily taken out without using a special tool or jig. As a result, it is possible to prevent the inner surface of the mounting hole, in particular, the sealing surface with which the second seal member 72 is in contact from being damaged.

  The functional component and the method for removing the functional component of the present invention have been described above based on the embodiments. However, the present invention is not limited to this embodiment. For example, the second seal member 72 in the embodiment has been described as a substantially C-shaped ring shape with a cross section having an opening on the inside, but is not limited to this shape, and the cross section is a solid circle, ellipse, rectangle, or the like. The shape can be selected as appropriate. The material of the second seal member 72 may be any material that can be locked to the locking portion, such as PTFE resin or metal.

  Moreover, about the structure of a functional component demonstrated in the Example, and the removal method, you may combine each Example or may remove and change a one part structure. For example, you may provide a 2nd latching | locking part in the both sides of the front end side and the rear end side of the 1st latching | locking part of a functional component, and make the 2nd latching part the rough surface intermittent in the circumferential direction of a functional component. It is also possible. According to the functional component and the method for removing the functional component of the present invention, the second locking portion for locking the seal member is provided on the outer surface of the housing of the functional component separately from the first locking portion. Any structure and removal method can be used as long as the seal member detached from the locking portion can be locked by the second locking portion.

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 2 Cylinder block 2a Cylinder 3 Piston 4 Cylinder head 4a Mounting hole 4b 1st hole part 4c Inclined part 4d 2nd hole part 4e Female thread 4f End surface 5 Pressure detection apparatus 10 Piezoelectric element 22 Conductive member 23 Cover member 30 Housing 31 1st 1 housing 31b front end side surface 31bt stepped portion 31ct stepped portion 31dt stepped portion 31et stepped portion 315at stepped portion 315 rear end side surface 315a inclined surface 32 second housing 330 outer peripheral surface 331 first outer peripheral surface 332 second outer peripheral surface 332a male screw 333 first 3 outer peripheral surface 334 fourth outer peripheral surface 334a end surface 40 diaphragm head 50 first electrode portion 55 second electrode portion 60 insulating ring 65 support member 71 first seal member 72 second seal member

Claims (12)

A functional component attached to a mounting hole leading to a combustion chamber of an internal combustion engine,
The functional component includes a housing that can be inserted into the mounting hole, and a first locking portion for locking a seal member that seals between the mounting hole and the outer surface of the housing on the outer surface of the housing,
The outer surface of the housing includes a second locking portion different from the first locking portion for locking the seal member.
Functional parts characterized by that. The second locking portion has a larger locking force of the seal member than the first locking portion.
The functional component according to claim 1.   The functional component according to claim 1, wherein at least a part of the first locking portion and the second locking portion is continuously provided. When the functional component is attached to the internal combustion engine, the second locking portion is the first locking when the combustion chamber side of the functional component is the front end side and the direction opposite to the front end side is the rear end side. Provided on the tip side from the part,
The functional component according to claim 1, wherein the functional component is a component. The second locking portion is provided on the rear end side from the first locking portion,
The functional component according to claim 1, wherein the functional component is a component. A plurality of the second locking portions are provided,
The functional component according to claim 1, wherein the functional component is a component. The second locking part is provided on the front end side and the rear end side across the first locking part,
The functional component according to claim 6. The second locking portion is composed of a stepped portion.
The functional component according to claim 1, wherein the functional component is a component. The second locking portion is formed of a surface rougher than the outer surface of the housing excluding the second locking portion.
The functional component according to claim 1, wherein the functional component is a component. A method of removing a functional component attached to a mounting hole that leads to a combustion chamber of an internal combustion engine,
The functional component locks the housing that can be inserted into the mounting hole, a first locking portion for locking a seal member that seals between the mounting hole and the outer surface of the housing, and the sealing member. A second locking portion different from the first locking portion is provided on the outer surface of the housing;
The seal member is locked to the second locking portion, and the functional component and the seal member are removed from the mounting hole.
A method of removing a functional component characterized by the above. When the functional component is attached to the internal combustion engine, the second locking portion is the first locking when the combustion chamber side of the functional component is the front end side and the direction opposite to the front end side is the rear end side. It is provided on the tip side from the part,
The removal of the functional component according to claim 10, wherein when the functional component is pulled out to the rear end side, the sealing member is locked to the second locking portion, and the functional component is removed from the mounting hole. Method. When the functional component is attached to the internal combustion engine, the second locking portion is the first locking when the combustion chamber side of the functional component is the front end side and the direction opposite to the front end side is the rear end side. It is provided on the rear end side from the part,
The said functional component is pushed to the front end side, the said sealing member is latched by the said 2nd latching | locking part, Then, it removes from the said attachment hole by pulling out the said functional component to the rear end side. The method for removing the functional component according to 10.

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