JP2021150024A - Manufacturing method of internal combustion engine member and manufacturing method of spark plug - Google Patents

Abstract

To provide a manufacturing method of a member for an internal combustion engine member and a manufacturing method of a spark plug, which can easily detect chips adhering to a step on the inner peripheral surface of a housing.SOLUTION: A manufacturing method of an internal combustion engine member including a cylindrical housing having at least one first surface facing the front end side or the rear end side on the inner peripheral surface forming a shaft hole includes a cutting step of obtaining the housing by cutting at least a part of a metal workpiece, an insertion step of inserting a rod having a second surface on the outer peripheral surface into the shaft hole such that the first surface and the second surface face each other, and a detection step of detecting an axial distance between the first surface and the second surface with the rod in the shaft hole after the insertion step.SELECTED DRAWING: Figure 4

Description

The present invention relates to a method for manufacturing a member for an internal combustion engine including a cylindrical housing and a method for manufacturing a spark plug.

Examples of internal combustion engine members having a tubular housing include spark plugs, glow plugs, heaters, pressure sensors, and the like. Patent Document 1 discloses a technique of cutting a metal work in a cutting process to obtain a main metal fitting (housing) and then assembling the main metal fitting to an insulator to obtain a spark plug.

Japanese Unexamined Patent Publication No. 9-27379

However, in the above technique, if chips generated by cutting adhere to the housing, it may cause trouble in a process after the cutting process. In particular, if there is a step on the inner peripheral surface of the housing, chips tend to adhere to it, which may cause troubles such as the chips hindering assembly with accurate dimensions when assembling other members to the housing. easy.

The present invention has been made to solve this problem, and provides a method for manufacturing a member for an internal combustion engine and a method for manufacturing a spark plug capable of detecting chips adhering to a step on the inner peripheral surface of a housing. I am aiming.

In order to achieve this object, the method for manufacturing an internal combustion engine member of the present invention has a shaft hole extending in the axial direction, and a first surface facing the front end side or the rear end side is provided on the inner peripheral surface forming the shaft hole. A method for manufacturing an internal combustion engine member having at least one tubular housing, wherein a cutting step of obtaining a housing by cutting at least a part of a metal workpiece and a rod having a second surface on an outer peripheral surface are used. An axial direction between the first surface and the second surface with a rod inserted in the shaft hole after the insertion step of inserting the first surface and the second surface into the shaft hole so as to face each other. It is provided with a detection step of detecting the distance between the two.

According to the method for manufacturing an internal combustion engine member of the present invention, after obtaining a housing having a first surface facing the front end side or the rear end side on the inner peripheral surface in the cutting process, a second surface on the outer peripheral surface in the insertion process. Insert the rod having the above into the shaft hole so that the first surface and the second surface face each other. In the detection step, since the distance in the axial direction between the first surface and the second surface is detected with the rod in the shaft hole, it is detected that chips are attached to the first surface of the housing. can. As a result, troubles caused by chips can be reduced in the process after the cutting process.

According to the method for manufacturing a spark plug of the present invention, after the main metal fitting is obtained through the detection step, the main metal fitting is assembled to the insulator in the assembling process, so that troubles in the assembling process caused by chips can be reduced. ..

It is one side sectional view of the spark plug in one Embodiment. It is sectional drawing of the main metal fitting. It is a side view of the bar in 1st Embodiment. It is sectional drawing of the main metal fitting which put the rod in the shaft hole. (A) and (b) are cross-sectional views of the main metal fittings in which the portion shown by V in FIG. 4 is enlarged. (A) and (b) are schematic views of the detection device. It is sectional drawing of the main metal fitting which put the rod in the shaft hole in 2nd Embodiment. It is sectional drawing of the main metal fitting which put the rod in the shaft hole in 3rd Embodiment.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a one-sided cross-sectional view of the spark plug 10 with the axis O as a boundary in one embodiment. The lower side of the paper surface in FIG. 1 is referred to as the front end side of the spark plug 10, and the upper side of the paper surface is referred to as the rear end side of the spark plug 10. The spark plug 10 includes a main metal fitting 20. The spark plug 10 is a kind of member for an internal combustion engine.

The insulator 11 is a cylindrical member in which a shaft hole 12 extending along the axis O is formed, and is formed of alumina or the like having excellent insulating properties and mechanical properties at high temperatures. The insulator 11 is provided with a first portion 13, a second portion 14, a third portion 15, and a fourth portion 16 in this order from the front end side to the rear end side. The first part 13 is thinner than the second part 14, and the second part 14 is thinner than the third part 15. Part 3 15 is thicker than Part 4 16.

The center electrode 17 is arranged on the tip end side of the shaft hole 12 of the insulator 11. The center electrode 17 is a rod-shaped electrode held by the insulator 11 along the axis O. In the center electrode 17, a core material having excellent thermal conductivity is embedded in the base material. The base material is formed of an alloy mainly composed of Ni or a metal material composed of Ni. The core material is formed of copper or an alloy containing copper as a main component. The core material can be omitted. The center electrode 17 is electrically connected to the terminal fitting 18 in the shaft hole 12 of the insulator 11. The terminal fitting 18 is a rod-shaped member to which a high-voltage cable (not shown) is connected, and is made of a conductive metal material (for example, low carbon steel or the like).

The main metal fitting 20 is a substantially cylindrical member formed of a conductive metal material (for example, low carbon steel or the like). The main metal fitting 20 is arranged on the outer periphery of the insulator 11. The main metal fitting 20 is provided with a body portion 21, a seat portion 23, a connecting portion 24, a tool engaging portion 25, and a rear end portion 26 in this order from the front end side to the rear end side.

The body portion 21 surrounds the first portion 13 and the second portion 14 of the insulator 11. A male screw 22 is formed on the outer peripheral surface of the body portion 21. The spark plug 10 is attached to a screw hole of an internal combustion engine (not shown) by a male screw 22.

The body portion 21 is provided with a shelf portion 27 that projects inward in the radial direction. The shelf portion 27 is continuous over the entire circumference of the body portion 21. The shelf portion 27 is located on the tip side of the step between the first portion 13 and the second portion 14 of the insulator 11. A packing (not shown) is interposed between the second portion 14 of the insulator 11 and the shelf portion 27. The packing is an annular plate material formed of a metal material such as iron or steel, which is softer than the metal material constituting the main metal fitting 20.

The seat portion 23 surrounds the rear end portion of the second portion 14 and the tip portion of the third portion 15 of the insulator 11. The thickness of the seat portion 23 is larger than the outer diameter of the male screw 22. The seat portion 23 regulates the amount of screwing of the male screw 22 into the internal combustion engine. The connecting portion 24 surrounds the third portion 15 of the insulator 11. The center of the connecting portion 24 in the axial direction is bent outward over the entire circumference.

The tool engaging portion 25 surrounds the rear end portion of the third portion 15 and the tip portion of the fourth portion 16 of the insulator 11. The tool engaging portion 25 is a portion for engaging a tool such as a wrench when the screw 22 is screwed into the screw hole of the internal combustion engine. The rear end portion 26 surrounds the tip end portion of the fourth portion 16 of the insulator 11 and is located closer to the rear end portion than the third portion 15 of the insulator 11. The rear end portion of the rear end portion 26 is bent inward over the entire circumference.

A seal portion 30 filled with powder such as talc is provided between the third portion 15 of the insulator 11 and the rear end portion 26 of the main metal fitting 20 over the entire circumference. The ground electrode 31 is a rod-shaped metal (for example, nickel-based alloy) member connected to the body 21 of the main metal fitting 20. The ground electrode 31 forms a spark gap with the center electrode 17.

The spark plug 10 is manufactured by, for example, the following method. First, the center electrode 17 is inserted into the shaft hole 12 of the insulator 11, and then the center electrode 17 and the terminal fitting 18 are electrically connected in the shaft hole 12. Next, after assembling the main metal fitting 20 to which the ground electrode 31 is connected in advance to the insulator 11, the ground electrode 31 is bent to obtain the spark plug 10.

In the process of manufacturing the spark plug 10, the connecting portion 24 and the rear end portion 26 are connected with the packing (not shown) arranged between the shelf portion 27 of the main metal fitting 20 and the second portion 14 of the insulator 11. The main metal fitting 20 is assembled to the insulator 11 by bending. In the portion of the main metal fitting 20 from the shelf portion 27 to the rear end portion 26, a compressive load in the axial direction is applied to the second portion 14 and the third portion 15 of the insulator 11 via the packing and the seal portion 30. As a result, the main metal fitting 20 holds the insulator 11.

FIG. 2 is a cross-sectional view including the axis O of the main metal fitting 40. The main metal fitting 40 is a kind of housing, and is an intermediate product of the main metal fitting 20 (see FIG. 1). The main metal fitting 40 is before the ground electrode 31 (see FIG. 1) is connected to the body 21, and before the screw 22 (see FIG. 1) is formed on the body 21. The connecting portion 24 and the rear end portion 26 of the main metal fitting 40 are not bent and have a cylindrical shape. In FIG. 2, the upper side of the paper surface is the front end side of the main metal fitting 40, and the lower side of the paper surface is the rear end side of the main metal fitting 40.

The main metal fitting 40 is a cylindrical member having a shaft hole 41 extending in the axial direction. First surfaces 43, 44, 45 are formed on the inner peripheral surface 42 of the main metal fitting 40. The first surface 43 is a surface located inside the seat portion 23 and faces the rear end side. The first surface 44 is a surface formed at the rear end of the shelf portion 27 and faces the rear end side. The first surface 45 is a surface formed at the tip of the shelf portion 27 and faces the tip side.

In this embodiment, the first surfaces 43, 44, and 45 are all conical surfaces. The diameter of the first surface 43 has a maximum value at the rear end of the first surface 43 and a minimum value at the tip of the first surface 43. The diameter of the first surface 44 has a maximum value at the rear end of the first surface 44 and a minimum value at the tip end of the first surface 44. The diameter of the first surface 45 has a maximum value at the tip of the first surface 45 and a minimum value at the rear end of the first surface 45.

The maximum value of the diameter of the first surface 43 is larger than the maximum value of the diameter of the first surface 44 and the maximum value of the diameter of the first surface 45. The minimum value of the diameter of the first surface 43 is substantially the same as the maximum value of the diameter of the first surface 44. The maximum value of the diameter of the first surface 44 is larger than the maximum value of the diameter of the first surface 45. The minimum value of the diameter of the first surface 44 is substantially the same as the minimum value of the diameter of the first surface 45.

The main metal fitting 40 is formed by cutting at least a part of a metal work (not shown). For example, after a work is obtained by performing a process other than cutting such as cold forging, a part of the inner peripheral surface 42 and the outer peripheral surface 46 is formed by cutting in the cutting process, and the main metal fitting 40 is obtained. The entire inner peripheral surface 42 and outer peripheral surface 46 of the main metal fitting 40 may be formed by cutting the work.

In the cutting process, the workpiece is cut while applying a cutting agent for lubrication and cooling. The cutting agent also has the effect of washing away the chips generated by cutting. However, since the chips that have entered the shaft hole 41 of the main metal fitting 40 do not easily flow, the chips tend to adhere to the inner peripheral surface 42. In particular, chips are likely to adhere to the first surfaces 43, 44, 45, which are steps on the inner peripheral surface 42. If chips adhere to the main metal fitting 40, it may cause troubles such as the chips hindering the assembly with accurate dimensions when the main metal fitting 40 is assembled to the insulator 11 in the process after the cutting process. There is a risk of becoming.

FIG. 3 is a side view of the rod 50 in the first embodiment. The rod 50 is a columnar member for removing chips adhering to the inner peripheral surface 42 of the main metal fitting 40 and detecting chips adhering to the first surface 45. In this embodiment, the rod 50 is made of synthetic resin. Examples of the synthetic resin constituting the rod 50 include polyacetal, polyamide, phenol resin, polyphenylene sulfide, and polyetheretherketone. The rod 50 may be made of metal as long as it has a hardness lower than that of the main metal fitting 40, and may be made of copper, for example.

The rod 50 includes a columnar first portion 51 and a columnar second portion 52 connected to the rear end side of the first portion 51. The diameter of the second part 52 is larger than the diameter of the first part 51. A second surface 53 connected to the outer peripheral surface of the first portion 51 is formed on the outer peripheral surface of the tip of the second portion 52. In this embodiment, the second surface 53 is a conical surface. The diameter of the second surface 53 has a minimum value at the tip of the second surface 53 and a maximum value at the rear end of the second surface 53.

FIG. 4 is a cross-sectional view of the main metal fitting 40 in which the rod 50 is inserted in the shaft hole 41. 5 (a) and 5 (b) are cross-sectional views of the main metal fitting 40 in which the portion shown by V in FIG. 4 is enlarged. As shown in FIG. 4, the main metal fitting 40 is arranged so that the body portion 21 (front end side) is located above the rear end portion 26 (rear end side).

In the insertion step, the rod 50 enters the shaft hole 41 so that the second surface 53 of the rod 50 faces the first surface 45 of the main metal fitting 40. From the tip end side of the main metal fitting 40, the first portion 51 of the rod 50 first enters the shaft hole 41, and then the second portion 52 enters the shaft hole 41. The diameter of the first part 51 is slightly smaller than the minimum value of the diameters of the first surfaces 44 and 45 of the main metal fitting 40. Therefore, the first portion 51 passes through the shelf portion 27 and enters the inside of the seat portion 23, the connecting portion 24, the tool engaging portion 25, and the rear end portion 26.

As a result, even if chips are attached to the inner peripheral surface of the shelf portion 27, the chips are pushed by the first portion 51 and fall when the first portion 51 passes through the shelf portion 27. The chips are made of metal, but the rod 50 is made of synthetic resin. Therefore, even if the first part 51 of the rod 50 pushes the chips adhering to the shelf part 27 and the chips rub against the shelf part 27 or the first part 51, even if the first part 51 is damaged, the shelf part 27 is damaged. It can be difficult.

As shown in FIG. 5A, the maximum value of the diameter of the second surface 53 of the rod 50 is larger than the minimum value of the diameter of the first surface 45 of the main metal fitting 40. Therefore, the movement of the rod 50 inserted into the shaft hole 41 of the main metal fitting 40 in the axial direction stops when the first surface 45 of the main metal fitting 40 regulates the second surface 53 of the rod 50. In the detection step, the distance between the first surface 45 of the main metal fitting 40 and the second surface 53 of the rod 50 in the axial direction is detected with the rod 50 inserted in the shaft hole 41 of the main metal fitting 40.

As shown in FIG. 5B, when chips 47 are attached to the first surface 45 of the main metal fitting 40, the chips 47 are cut between the first surface 45 of the main metal fitting 40 and the second surface 53 of the rod 50. Waste 47 intervenes. In this case, as shown in FIG. 5A, the second surface of the rod 50 is equal to the amount of chips 47, as compared with the case where the first surface 45 of the main metal fitting 40 and the second surface 53 of the rod 50 are in contact with each other. 53 floats in the axial direction with respect to the first surface 45 of the main metal fitting 40.

6 (a) and 6 (b) are schematic views of an insertion machine 54 for inserting the rod 50 into the shaft hole 41 of the main metal fitting 40. FIG. 6A is a schematic view of the insertion machine 54 before the rod 50 is inserted into the main metal fitting 40, and FIG. 6B is a schematic view of the insertion machine 54 after the rod 50 is inserted into the main metal fitting 40. It is a figure. The inserter 54 includes a coupling portion 55 that couples the rod 50 and the detector 56. The insertion machine 54 is a device that moves the rod 50 and the detector 56 integrated by the coupling portion 55 in the axial direction of the rod 50. The joint portion 55 has a rigidity that does not elastically deform even when a force due to movement when the rod 50 is taken in and out of the main metal fitting 40 is applied. In this embodiment, the detector 56 is a dial gauge. The detector 56 detects the magnitude of the movement of the stylus 57 that is pushed by the base 58 and moves linearly.

In the detection process, the machined main metal fitting 40 is arranged at the same position in the axial direction with respect to the base 58 of the insertion machine 54. The rod 50 is inserted into the main metal fitting 40 with a slight force that does not crush the chips 47. When chips 47 are attached to the first surface 45 of the main metal fitting 40 as shown in FIG. 5 (b), the first surface 45 of the main metal fitting 40 and the rod 50 are attached as shown in FIG. 5 (a). The movement of the stylus 57 of the detector 56 is smaller than that in contact with the second surface 53. As a result, the axial distance between the first surface 45 of the main metal fitting 40 and the second surface 53 of the rod 50 is detected. As a result, the presence or absence of chips 47 between the first surface 45 of the main metal fitting 40 and the second surface 53 of the rod 50 can be determined.

The inclination angle (angle with respect to the axis O) of the second surface 53 of the rod 50 (see FIG. 5A) is set to be substantially the same as the inclination angle of the first surface 45 of the main metal fitting 40. More specifically, the inclination angle of the second surface 53 of the rod 50 is set within ± 3 ° of the inclination angle of the first surface 45 of the main metal fitting 40. As a result, the first surface 45 and the second surface 53 can be brought into close contact with each other in a wide range, so that the chips 47 (see FIG. 5B) interposed between the first surface 45 and the second surface 53 can be brought into close contact with each other. Chips 47 can be detected even if the size is small.

The second embodiment will be described with reference to FIG. 7. In the first embodiment, a case of determining whether or not chips 47 are attached to the first surface 45 of the main metal fitting 40 has been described. On the other hand, in the second embodiment, a case of determining whether or not chips (not shown) are attached to the first surface 43 of the main metal fitting 40 will be described. The same parts as those described in the first embodiment are designated by the same reference numerals, and the following description will be omitted.

FIG. 7 is a cross-sectional view of the main metal fitting 40 in which the rod 60 in the second embodiment is inserted in the shaft hole 41. As shown in FIG. 7, the main metal fitting 40 is arranged so that the body portion 21 (front end side) is located below the rear end portion 26 (rear end side).

The rod 60 includes a columnar first portion 61 and a columnar second portion 62 connected to the rear end side of the first portion 61. The diameter of the second part 62 is larger than the diameter of the first part 61. A second surface 63 connected to the outer peripheral surface of the first portion 61 is formed on the outer peripheral surface of the tip of the second portion 62. In this embodiment, the second surface 63 is a conical surface. The diameter of the second surface 63 has a minimum value at the tip of the second surface 63 and a maximum value at the rear end of the second surface 63.

In the insertion step, the rod 60 enters the shaft hole 41 so that the second surface 63 of the rod 60 faces the first surface 43 of the main metal fitting 40. From the rear end side of the main metal fitting 40, the first portion 61 of the rod 60 first enters the shaft hole 41, and then the second portion 62 enters the shaft hole 41. The diameter of the first portion 61 is slightly smaller than the inner diameter of the shelf portion 27 of the main metal fitting 40. The diameter of the second portion 62 is slightly smaller than the inner diameter of the seat portion 23, the connecting portion 24, the tool engaging portion 25, and the rear end portion 26 of the main metal fitting 40. Therefore, the first portion 61 passes through the shelf portion 27, and the second portion 62 enters the inside of the seat portion 23, the connecting portion 24, the tool engaging portion 25, and the rear end portion 26.

As a result, even if chips are attached to the inner peripheral surface of the shelf portion 27, the chips are pushed by the first portion 61 and fall when the first portion 61 passes through the shelf portion 27. The maximum value of the diameter of the second surface 63 of the rod 60 is larger than the minimum value of the diameter of the first surface 43 of the main metal fitting 40. Therefore, the movement of the rod 60 inserted into the shaft hole 41 of the main metal fitting 40 in the axial direction stops when the first surface 43 of the main metal fitting 40 regulates the second surface 63 of the rod 60.

In the detection step, the distance between the first surface 43 of the main metal fitting 40 and the second surface 63 of the rod 60 in the axial direction is detected with the rod 60 inserted in the shaft hole 41 of the main metal fitting 40. Thereby, it can be determined whether or not chips are attached to the first surface 43 of the main metal fitting 40.

The inclination angle (angle with respect to the axis O) of the second surface 63 of the rod 60 is set within ± 3 ° of the inclination angle of the first surface 43 of the main metal fitting 40. As a result, the first surface 43 and the second surface 63 can be brought into close contact with each other in a wide range, so that chips can be detected even if the size of the chips interposed between the first surface 43 and the second surface 63 is small. can.

The third embodiment will be described with reference to FIG. In the second embodiment, a case of determining whether or not chips are attached to the first surface 43 of the main metal fitting 40 has been described. On the other hand, in the third embodiment, a case of determining whether or not chips are attached to the first surface 44 of the main metal fitting 40 will be described. The same parts as those described in the first embodiment are designated by the same reference numerals, and the following description will be omitted.

FIG. 8 is a cross-sectional view of the main metal fitting 40 in which the rod 70 according to the third embodiment is inserted into the shaft hole 41. As shown in FIG. 8, the main metal fitting 40 is arranged so that the body portion 21 (front end side) is located below the rear end portion 26 (rear end side).

The rod 70 includes a columnar first portion 71 and a columnar second portion 72 connected to the rear end side of the first portion 71. The diameter of the second part 72 is larger than the diameter of the first part 71. A second surface 73 connected to the outer peripheral surface of the first portion 71 is formed on the outer peripheral surface of the tip of the second portion 72. In this embodiment, the second surface 73 is a conical surface. The diameter of the second surface 73 has a minimum value at the tip of the second surface 73 and a maximum value at the rear end of the second surface 73.

In the insertion step, the rod 70 enters the shaft hole 41 so that the second surface 73 of the rod 70 faces the first surface 44 of the main metal fitting 40. From the rear end side of the main metal fitting 40, the first portion 71 of the rod 70 first enters the shaft hole 41, and then the second portion 72 enters the shaft hole 41. The diameter of the first portion 71 is slightly smaller than the inner diameter of the shelf portion 27 of the main metal fitting 40. The diameter of the second portion 72 is slightly smaller than the inner diameter of the portion of the body portion 21 of the main metal fitting 40 on the rear end side of the shelf portion 27. Therefore, the first part 71 passes through the shelf part 27, and the second part 72 enters the inside of the body part 21.

As a result, even if chips are attached to the inner peripheral surface of the shelf portion 27, the chips are pushed by the first portion 71 and fall when the first portion 71 passes through the shelf portion 27. The maximum value of the diameter of the second surface 73 of the rod 70 is larger than the minimum value of the diameter of the first surface 44 of the main metal fitting 40. Therefore, the movement of the rod 70 inserted into the shaft hole 41 of the main metal fitting 40 in the axial direction stops when the first surface 44 of the main metal fitting 40 regulates the second surface 73 of the rod 70.

In the detection step, the distance between the first surface 44 of the main metal fitting 40 and the second surface 73 of the rod 70 in the axial direction is detected with the rod 70 inserted in the shaft hole 41 of the main metal fitting 40. Thereby, it can be determined whether or not chips are attached to the first surface 44 of the main metal fitting 40.

The inclination angle (angle with respect to the axis O) of the second surface 73 of the rod 70 is set within ± 3 ° of the inclination angle of the first surface 44 of the main metal fitting 40. As a result, the first surface 44 and the second surface 73 can be brought into close contact with each other in a wide range, so that chips can be detected even if the size of the chips interposed between the first surface 44 and the second surface 73 is small. can.

Although the present invention has been described above based on the embodiments, the present invention is not limited to the above embodiments, and various improvements and modifications can be made without departing from the spirit of the present invention. It can be easily inferred.

In the embodiment, it is determined whether or not chips are attached to the main metal fitting 40 before the ground electrode 31 is connected to the body 21 and before the screw 22 is formed on the body 21. As explained, it is not necessarily limited to this. Of course, it is possible to determine whether or not chips are attached to the main metal fitting after the ground electrode 31 is connected to the body 21 and the main metal fitting after the screw 22 is formed on the body 21. be.

In the embodiment, the case where the first surfaces 43, 44, and 45 of the main metal fitting 40 are all conical surfaces has been described, but the present invention is not necessarily limited to this. Of course, it is possible to make at least one of the first surfaces 43, 44, 45 of the main metal fitting 40 a surface perpendicular to the axis O. In this case, a second surface perpendicular to the axis O is provided on the outer peripheral surface of the rod inserted into the main metal fitting. Of course, it is also possible to make at least one of the first surfaces 43, 44, and 45 into a ball band. In this case, a second surface made of a ball band is provided on the outer peripheral surface of the rod inserted into the main metal fitting.

In the embodiment, the case where the detector 56 for detecting the axial distance between the first surface 45 of the main metal fitting 40 and the second surface 53 of the rod 50 is a dial gauge has been described, but the present invention is not necessarily limited to this. .. For example, as a detector, it is naturally possible to use a light transmission type or light reflection type range finder or a contact type measuring device that detects the distance between the base 58 and the stylus.

In the embodiment, a case has been described in which it is determined whether or not chips are attached to the main metal fitting 40 by using rods 50, 60, 70 provided with one second surface 53, 63, 73 respectively. , Not necessarily limited to this. Of course, it is possible to provide a plurality of second surfaces on the rod. For example, the second surface 63 of the rod 60 in the second embodiment and the second surface 73 of the rod 70 in the third embodiment can be provided on one rod.

In the embodiment, a case where it is determined only once whether or not chips are attached to the first surfaces 43, 44, 45 of the main metal fitting 40 by using the rods 50, 60, 70 has been described, but this is not necessarily the case. It is not limited. It is of course possible to use two or more rods 50, 60, 70 to determine whether or not chips are attached to two or more surfaces of the first surfaces 43, 44, 45 of the main metal fitting 40.

In the embodiment, the spark plug 10 is exemplified as a member for an internal combustion engine, and the main metal fitting 40 of the spark plug 10 is exemplified as a housing, but the description is not limited to this. It is of course possible to apply the methods described in the embodiments to housings of other internal combustion engine members such as glow plugs, heaters, pressure sensors and the like.

In the embodiment, the case where the rods 50, 60, and 70 are inserted from above the main metal fitting 40 with the main metal fitting 40 upright and the chips adhering to the main metal fitting 40 are dropped has been described, but the present invention is not necessarily limited to this. It's not a thing. Insert the rods 50, 60, 70 into the main metal fitting 40 with the main metal fitting 40 lying down, or insert the rods 50, 60, 70 from under the main metal fitting 40 with the main metal fitting 40 upright. Of course, it is possible to remove the chips adhering to the metal fitting 40. In these cases, it is naturally possible to introduce a gas such as compressed air into the main metal fitting 40 so that the chips removed by the rods 50, 60, and 70 can be easily discharged to the outside of the main metal fitting 40.

10 Spark plug (member for internal combustion engine)
11 Insulator 40 Main metal fitting (housing)
41 Shaft hole 42 Inner peripheral surface 43,44,45 First surface 50,60,70 Rod 53,63,73 Second surface O Axis line

Claims (4)

A method for manufacturing an internal combustion engine member having a cylindrical housing having a shaft hole extending in the axial direction and having at least one first surface facing the front end side or the rear end side on the inner peripheral surface forming the shaft hole. There,
The cutting process of obtaining the housing by cutting at least a part of the metal workpiece,
An insertion step of inserting a rod having a second surface on the outer peripheral surface into the shaft hole so that the first surface and the second surface face each other.
Manufacture of a member for an internal combustion engine including a detection step of detecting a distance in the axial direction between the first surface and the second surface with the rod inserted in the shaft hole after the insertion step. Method. The method for manufacturing an internal combustion engine member according to claim 1, wherein the rod is made of a synthetic resin. The method for manufacturing an internal combustion engine member according to claim 1 or 2, wherein the housing is a main metal fitting of a spark plug. A method for manufacturing a spark plug, comprising an assembling step of assembling the main metal fitting to an insulator after obtaining the main metal fitting through the detection step according to the method for manufacturing an internal combustion engine member according to claim 3.

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