JP5741607B2 - Manufacturing method of screw fastening parts - Google Patents

Description

  The present invention relates to a method of manufacturing a component that is screwed and fastened.

  As an injector that injects fuel into an internal combustion engine, an injector integrated with a sensor device that detects fuel pressure has been proposed (see, for example, Patent Document 1). Specifically, a screw is formed in the sensor housing, a female screw is formed in the injector body, and these screws are screwed together to fasten the sensor device to the injector body.

JP 2012-215507 A

  However, when the two parts are fastened by screwing the screws, the position where the sensor housing stops in the rotational direction with respect to the injector body after fastening is not fixed at a specific position.

  In view of the above points, an object of the present invention is to position a specific part of one part in a specific direction of the other part when the two parts are fastened by screwing.

  In order to achieve the above object, according to the first aspect of the present invention, the first machining step for forming the female screw (11) and the first seating surface (12) on the first member (1), and the female screw are screwed together. And a second machining step of forming a second seating surface (212) in contact with the first seating surface and a second seating surface (212) on the second member (21), When the predetermined specific direction among the radial directions of the female screw is set as the female screw reference radial direction, and the predetermined specific direction among the radial directions of the male screw is set as the male screw reference radial direction, the first processing step The first member is set in a female screw processing machine (5) for processing a female screw, a pilot hole machining step for machining a pilot hole (11a) and a first seating surface of the female screw, and a female screw on the first seating surface A first seating surface position measuring step for measuring the position in the axial direction, and from the first seating surface to the female screw axial direction. It has a female thread machining process for machining the female thread so that the female thread valley or crest is located at a constant distance and in the female thread reference radial direction, and the second machining process is a male thread processing machine that processes the male thread (6) A second member holding step of holding the second member on the first chuck (61), a second seating surface processing step of processing the second seating surface, and measuring the position of the second seating surface in the screw axis direction. A second seating surface position measuring step, and a male threading step of machining the screw so that a thread crest or trough is located in the male screw reference radial direction at a predetermined distance from the second seating surface in the male screw axial direction. It is characterized by providing.

  According to this, when screwing together and fastening the first member and the second member, a specific part of the second member can be positioned in a specific direction of the first member.

  In addition, the code | symbol in the bracket | parenthesis of each means described in this column and the claim shows the correspondence with the specific means as described in embodiment mentioned later.

It is a figure which shows the principal part of the injector to which the method which concerns on 1st Embodiment of this invention is applied. It is A arrow directional view of FIG. It is a figure which shows the sensor apparatus of FIG. It is a figure with which it uses for description of the pilot hole manufacturing process in the injector body of FIG. It is a figure where it uses for description of the 1st seating surface position measurement process in the injector body of FIG. It is a figure where it uses for description of the internal thread machining process in the injector body of FIG. It is sectional drawing with which it uses for description of the 2nd seating surface processing process in the sensor apparatus of FIG. It is sectional drawing with which it uses for description of the 2nd seating surface position measurement process in the sensor apparatus of FIG. It is sectional drawing with which it uses for description of the external thread processing process in the sensor apparatus of FIG. It is sectional drawing with which it uses for description of the 2nd seating surface process process in the sensor apparatus manufactured by the method which concerns on 2nd Embodiment of this invention. It is sectional drawing with which it uses for description of the 2nd seating surface position measurement process in the sensor apparatus manufactured by the method which concerns on 2nd Embodiment of this invention. It is sectional drawing with which it uses for description of the external thread processing process in the sensor apparatus manufactured by the method which concerns on 2nd Embodiment of this invention. It is sectional drawing with which it uses for description of the marking process in the sensor apparatus manufactured by the method which concerns on 2nd Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, the same or equivalent parts are denoted by the same reference numerals in the drawings.

(First embodiment)
A first embodiment of the present invention will be described.

  As shown in FIGS. 1 to 3, the injector injects high-pressure fuel supplied from a common rail (not shown) into a cylinder of a diesel internal combustion engine from a nozzle (not shown), and is made of metal as a first member. A sensor device 2 that detects the pressure of the high-pressure fuel is screwed to the injector body 1.

  The injector body 1 is formed with a female screw 11 into which the sensor device 2 is screwed. A first seating surface 12 with which the end of the sensor device 2 abuts is formed at the bottom of the hole in which the female thread 11 is formed in the injector body 1. The first seating surface 12 is a plane perpendicular to the axis of the female screw 11 (hereinafter referred to as the female screw axis).

  The sensor device 2 includes a housing 21 as a second member, and the housing 21 includes a metal cylindrical stem portion 21A and a metal disc-shaped flange portion 21B, and the stem portion 21A and the flange portion 21B. Are welded and integrated. In addition, the housing 21 may be formed by forging the stem portion 21A and the flange portion 21B, for example.

  A male screw 211 is formed on the outer peripheral surface of the stem portion 21 </ b> A so as to be screwed into the female screw 11 of the injector body 1.

  A second seating surface 212 that abuts on the first seating surface 12 of the injector body 1 is formed at the end of the stem portion 21A in the direction of the axis of the male screw 211 (hereinafter referred to as the male screw axis). The second seating surface 212 is a plane perpendicular to the male screw axis.

  A thin-walled portion 213 that is deformed according to the pressure of the fuel guided through the branch passage 14 is formed at the end of the stem portion 21A in the male screw axial direction (the end opposite to the second seating surface 212). Yes. A sensor chip 22 whose resistance value changes according to the deformation of the thin portion 213 (in other words, according to the fuel pressure in the high pressure passage 13) is attached to the thin portion 213.

  An engagement portion 214 is formed on the outer peripheral side surface of the flange portion 21B to engage with a jig (not shown) that rotates the sensor device 2 during assembly. The flange portion 21B is viewed in the male screw axial direction. Sometimes it is polygonal.

  A mold IC 23 is disposed at the end of the flange portion 21B in the male screw axial direction so as to surround the thin portion 213 and the sensor chip 22. The mold IC 23 is joined to the flange portion 21B with an adhesive.

  The mold IC 23 is a signal processing circuit IC (not shown) that outputs an electrical signal corresponding to pressure based on a change in the resistance value of the sensor chip 22, and a lead frame 231 that is electrically connected to the signal processing circuit IC. Etc.

  The signal processing circuit IC and the lead frame 231 are sealed with a mold resin layer 232 made of a resin having high electrical insulation. A sensor terminal 233 which is a part of the lead frame 231 protrudes from the outer peripheral side surface of the mold resin layer 232.

  A cover 24 made of a metal plate that covers the space in which the sensor chip 22 is disposed is disposed on the opposite side of the mold IC 23 from the housing. The cover 24 is joined to the mold IC 23 with an adhesive.

  When the sensor device 2 is screwed onto the injector body 1, a specific part of the sensor device 2 is positioned in a specific direction of the injector body 1. Specifically, when the sensor device 2 is screwed into the injector body 1, the sensor terminal 233 of the sensor device 2 is positioned on the nozzle mounting side (in the injector body 1) with reference to the positions of the female screw axis and the male screw axis ( That is, it is located on the left side of the drawing in FIG.

  In addition, the predetermined specific direction among the radial directions of the female screw 11 is hereinafter referred to as a female screw reference radial direction. Specifically, the female screw reference radial direction is a direction on the nozzle mounting side of the injector body 1 with respect to the position of the female screw axis.

  Next, the processing method of the internal thread 11 in the injector body 1 is demonstrated based on FIGS.

  A female thread processing machine 5 for processing the internal thread 11 is a machining center, a processing machine base 51 for setting an injector body 1 as a work, a processing head 52 for driving a cutting tool or a measuring instrument, and a processing head based on a program. The control part 53 etc. which control the action | operation of 52 are provided.

  First, as shown in FIG. 4, in the prepared hole machining step, the injector body 1 is set on the machine table 51 and then the end mill 54 mounted on the machining head 52 is used to prepare the prepared holes 11 a and the first seats of the female screw 11. The surface 12 is processed.

  At this time, a position that is a first predetermined distance L1 away from the surface of the machining head 52 on which the injector body 1 is set in the direction of the female screw axis (that is, the vertical direction on the paper surface) As the first seating surface target processing position P1, the internal hole 11a of the female screw 11 and the first seating surface 12 are processed. The first seating surface target machining position P1 is stored in the control unit 53 in advance.

  Subsequently, as shown in FIG. 5, in the first seating surface position measuring step, an actual machining position P2 (hereinafter referred to as a first machining position P2) of the first seating surface 12 in the direction of the female screw axis is measured by a measuring instrument 55 attached to the machining head 52. 1 seating surface actual machining position P2) is measured.

  Subsequently, in the female thread machining condition calculation step, a machining condition in which a valley of the female thread 11 is formed at a portion that is separated from the first seating surface 12 by the second predetermined distance L2 in the female thread axial direction and in the female thread reference radial direction is controlled. Calculated by the unit 53. A detailed calculation method of the machining conditions will be described later. Note that the position away from the first seating surface 12 in the direction of the female screw axis by the second predetermined distance L2 is an arbitrary position within the region where the female screw 11 is formed.

  Subsequently, in the internal thread machining step, as shown in FIG. 6, the internal thread 11 is formed by the planet tap 56 based on the machining conditions calculated in the internal thread machining condition calculation step.

  Specifically, the planet tap 56 moves to the predetermined position along the female screw axis toward the first seating surface 12 (that is, descends), then moves in the female screw reference radial direction while rotating, and the pilot hole 11a. The processing of the female screw 11 is started in contact with the wall surface surrounding. Further, the planet tap 56 revolves around the female screw axis and moves (that is, rises) away from the first seating surface 12 to form the female screw 11 up to the opening position of the lower hole 11a.

  Here, a calculation method of the machining condition in the female thread machining condition calculation step will be described.

  When the lower end position of the planet tap 56 when starting the machining of the internal thread 11 is defined as the tap insertion depth, in the following description, the set value of the tap insertion depth stored in the control unit 53 in advance is used as the reference tap. It is called insertion depth P3, and the target value of tap insertion depth when actual machining is performed is called target tap insertion depth P4.

  Further, when the machining is actually performed at the reference tap insertion depth P3, the female screw 11 is provided at the second predetermined distance L2 away from the first seating surface target machining position P1 in the female screw axial direction and in the female screw reference radial direction. A valley is formed.

  First, an error ΔL1 (hereinafter, referred to as a first seating surface machining position error ΔL1) between the first seating surface target machining position P1 and the first seating surface actual machining position P2 is calculated. Subsequently, the reference tap insertion depth P3 is corrected, in other words, the target tap insertion depth P4 is calculated by adding or subtracting the first seating surface machining position error ΔL1 to the reference tap insertion depth P3. This target tap insertion depth P4 is a machining condition calculated in the female thread machining condition calculation step.

  Then, by executing the screw machining step described above based on the target tap insertion depth P4 calculated in this way, the second predetermined distance L2 away from the first seating surface 12 in the female screw axial direction and the female screw reference diameter. A trough of the female screw 11 is formed at a site in the direction.

  Next, a method for processing the male screw 211 in the sensor device 2 will be described with reference to FIGS.

  The external thread processing machine 6 that processes the external thread 211 includes a first chuck 61 that holds the housing 21, a first cutting tool 62 that processes the second seating surface 212, a second cutting tool 63 that processes the external thread 211, and a second. A measuring device 64 that measures an actual machining position P5 in the male screw axis direction of the seating surface 212 (hereinafter referred to as a second seating surface actual machining position P5), and a controller 65 that controls the operation of the first chuck 61 and the like based on a program. Etc.

  First, in the second member holding step, as shown in FIG. 7, positioning is performed such that a specific engagement portion 214 of the engagement portion 214 of the flange portion 21 </ b> B is positioned at a specific portion in the rotation direction of the first chuck 61. Then, the flange portion 21 </ b> B is held by the first chuck 61.

  In addition, the predetermined specific direction among the radial directions of the external thread 211 is hereinafter referred to as an external thread reference radial direction. Specifically, the male screw reference radial direction is a direction on the specific engaging portion 214 side of the engaging portion 214 of the flange portion 21B with reference to the position of the male screw axis. Hereinafter, the engagement portion on the male screw reference radial direction side of the engagement portion 214 of the flange portion 21B is referred to as a reference radial direction engagement portion 214a.

  Subsequently, in the second seating surface machining step, a predetermined position in the male screw axis direction is set as a target machining position P6 of the second seating surface 212 (hereinafter referred to as a second seating surface target machining position P6). Is processed by the first cutting tool 62. The second seating surface target machining position P6 is stored in the control unit 65 in advance.

  Subsequently, in the second seating surface position measuring step, as shown in FIG. 8, the second seating surface actual machining position P <b> 5 is measured by the measuring device 64.

  Subsequently, in the male thread machining condition calculation step, a machining condition in which a thread 211 of the screw 211 is formed in a part in the male screw reference radial direction and a second predetermined distance L2 away from the second seating surface 212 in the male screw axial direction. Calculated by the control unit 65.

  A method for calculating the machining conditions will be described with reference to FIG.

  In addition, about the feed direction stop position of the 2nd cutting tool 63 before processing the external thread 211, the feed direction reference stop position of the 2nd cutting tool 63 previously memorize | stored in the control part 65 is set with the 2nd cutting tool reference stop position P7. The actual feed direction stop position of the second cutting tool 63 is referred to as a second cutting tool actual stop position P8.

  Further, before processing the male screw 211, the rotation stop position of the first chuck 61 is set so that the reference radial direction engaging portion 214a is at a specific position (for example, the lower side).

  Further, after the second cutting tool 63 is stopped at the second cutting tool reference stop position P7, when the rotation of the first chuck 61 and the feeding of the second cutting tool 63 are performed to process the screw 211, the second seating surface is obtained. A thread 211 of the screw 211 is formed at a part of the male thread reference radial direction and a second predetermined distance L2 away from the target machining position P6.

  First, an error ΔL2 (hereinafter referred to as a second seating surface machining position error ΔL2) between the second seating surface target machining position P6 and the second seating surface actual machining position P5 is calculated.

  Subsequently, the second cutting tool reference stop position P7 is corrected, in other words, the second cutting tool actual stop position P8 is calculated by adding or subtracting the second seating surface machining position error ΔL2 to the second cutting tool reference stop position P7. To do. This second cutting tool actual stop position P8 is a machining condition calculated in the male thread machining condition calculation step.

  Subsequently, in the male thread machining step, the screw 211 is formed by the second cutting tool 63 based on the machining conditions calculated in the male screw machining condition calculation step.

  Specifically, after the second cutting tool 63 is stopped at the second cutting tool actual stop position P8, the screw 211 is processed by synchronizing the rotation of the first chuck 61 and the feeding of the second cutting tool 63, A crest of the screw 211 is formed at a portion that is separated from the second seating surface 212 by a second predetermined distance L2 in the male screw axial direction and in the male screw reference radial direction.

  Thereafter, other components of the sensor device 2 are assembled to the stem portion 21A in the joining step. Specifically, the sensor terminal 233 is positioned so as to be positioned on the reference radial direction engaging portion 214a side with respect to the position of the male screw axis, and the components of the sensor device 2 are joined.

  Here, since the female thread 11 of the injector body 1 is a trough at a position away from the first seating surface 12 of the injector body 1 by the second predetermined distance L2 in the axial direction of the female screw, the second seating surface 212 of the sensor device 2 may In the state of being brought into contact with one seating surface 12, the external thread 211 of the sensor device 2 is a mountain at a position away from the second seating surface 212 by a second predetermined distance L2 in the male screw axial direction.

  Therefore, the male screw reference radial direction coincides with the female screw reference radial direction. As described above, the female screw reference radial direction is the direction on the nozzle mounting side of the injector body 1 with respect to the position of the female screw axis.

  Therefore, when the sensor device 2 manufactured as described above is screwed and fastened to the injector body 1, the sensor terminal 233 of the sensor device 2 is based on the positions of the female screw axis and the male screw axis. It is located on the nozzle mounting side.

  In the above embodiment, the injector body 1 is mounted on the processing machine base 51 and the internal thread 11 is processed. However, the cylindrical portion of the injector body 1 is held by the chuck and the internal thread 11 is processed. You may do it. In this case, a position that is a first predetermined distance L1 away from the center position of the chuck (that is, the center position of the injector body 1) in the female screw axial direction is defined as a first seating surface target processing position P1.

(Second Embodiment)
A second embodiment of the present invention will be described. In this embodiment, the processing method of the sensor device 2 is changed, and the other parts are the same as those in the first embodiment, and therefore only different parts will be described.

  In this embodiment, a screw is formed in the stem portion 21A before integrating the stem portion 21A as the main member and the flange portion 21B as the sub member.

  As shown in FIG. 13, the external thread processing machine 6 includes a second chuck 66 that holds the outer peripheral portion of the external thread 211 in the stem portion 21A, and a cylinder on the opposite side of the second seating surface 212 in the stem portion 21A. A marker 67 for giving a screw reference radial direction mark to the part is provided. Further, the rotation stop position of the first chuck 61 is always controlled to a fixed position.

  First, in the second member holding step, as shown in FIG. 10, the cylindrical portion of the stem portion 21 </ b> A opposite to the second seating surface 212 is held by the first chuck 61. In the present embodiment, the lower side of the stem portion 21A is the male screw reference radial direction in a state where the stem portion 21A is held by the first chuck 61.

  Subsequently, in the second seating surface processing step, the second seating surface 212 is processed by the first cutting tool 62.

  Subsequently, in the second seating surface position measuring step, as shown in FIG. 11, the measuring device 64 measures the second seating surface actual machining position P5.

  Subsequently, in the male thread machining condition calculation step, a machining condition in which a thread 211 of the screw 211 is formed in a part in the male screw reference radial direction and a second predetermined distance L2 away from the second seating surface 212 in the male screw axial direction. Calculated by the control unit 65.

  A method for calculating the machining conditions will be described with reference to FIG.

  First, the second seating surface machining position error ΔL2 is calculated. Subsequently, the second cutting tool reference stop position P7 is corrected, in other words, the second cutting tool actual stop position P8 is calculated by adding or subtracting the second seating surface machining position error ΔL2 to the second cutting tool reference stop position P7. To do. This second cutting tool actual stop position P8 is a machining condition calculated in the male thread machining condition calculation step.

  Subsequently, in the male thread machining step, the screw 211 is formed by the second cutting tool 63 based on the machining conditions calculated in the male screw machining condition calculation step.

  Specifically, after the second cutting tool 63 is stopped at the second cutting tool actual stop position P8, the screw 211 is processed by synchronizing the rotation of the first chuck 61 and the feeding of the second cutting tool 63, A crest of the screw 211 is formed at a portion that is separated from the second seating surface 212 by a second predetermined distance L2 in the male screw axial direction and in the male screw reference radial direction.

  Then, in a marking process, as shown in FIG. 13, the mark which shows a male screw reference | standard radial direction is provided to 21 A of stem parts.

  That is, in the marking step, the outer peripheral portion of the external thread 211 in the stem portion 21A is held by the second chuck 66 while the stem portion 21A is held by the first chuck 61 so that the stem portion 21A does not rotate. The holding by the first chuck 61 is released. Then, the male screw reference radial direction indicating the male screw reference radial direction on the portion of the stem portion 21A held by the first chuck 61, in other words, the cylindrical portion on the opposite side of the second seating surface 212 in the stem portion 21A. A mark is given by a marker 67 to clearly indicate the male screw reference radial direction.

  Thereafter, other components of the sensor device 2 are assembled to the stem portion 21A in the joining step. Specifically, the sensor terminal 233 is positioned so as to be positioned on the screw reference radial direction mark side with respect to the position of the male screw axis, and the components of the sensor device 2 are joined.

  As a result, when the sensor device 2 manufactured as described above is screwed into the injector body 1 and fastened, the sensor terminal 233 of the sensor device 2 is positioned on the basis of the positions of the female screw axis and the male screw axis. 1 on the nozzle mounting side.

(Other embodiments)
In each of the above embodiments, the present invention is applied to an injector, but the present invention can also be applied to other than the injector.

  In each of the above embodiments, a sensor device that detects pressure is shown. However, the present invention can also be applied to a sensor device that detects a physical quantity other than pressure.

  Further, in each of the above-described embodiments, the direction of the male screw 211 that passes through the second predetermined distance L2 from the second seating surface 212 in the male screw axial direction and passes through the portion where the thread of the male screw 211 is located is the male screw 211. The valley of the female screw 11 is positioned at the second radial distance L2 from the first seating surface 12 in the direction of the female screw axis in the reference radial direction, but these can be changed as follows. .

  That is, among the radial directions of the external thread 211, the direction passing through the portion where the trough of the external thread 211 is located at the second predetermined distance L2 from the second seating surface 212 in the external thread axial direction is defined as the external thread reference radial direction. The threads of the female screw 11 may be located at a position away from the first seating surface 12 by the second predetermined distance L2 in the female screw axial direction.

  In each of the above embodiments, the female screw reference radial direction is set to the nozzle mounting side direction of the injector body 1 with respect to the position of the female screw axis, but the female screw reference radial direction is the position of the female screw axis. You may make it the direction of the non-nozzle mounting side (namely, the paper surface right side of FIG. 1) in the injector body 1 on the basis. In this case, when the sensor device 2 is screwed onto the injector body 1, the sensor terminal 233 of the sensor device 2 is positioned on the side opposite to the nozzle mounting on the injector body 1 with reference to the positions of the female screw axis and the male screw axis. Will do.

  Further, the present invention is not limited to the above-described embodiment, and can be appropriately changed within the scope described in the claims.

  Further, the above embodiments are not irrelevant to each other, and can be combined as appropriate unless the combination is clearly impossible.

  In each of the above-described embodiments, it is needless to say that elements constituting the embodiment are not necessarily essential unless explicitly stated as essential and clearly considered essential in principle. Yes.

  Further, in each of the above embodiments, when numerical values such as the number, numerical value, quantity, range, etc. of the constituent elements of the embodiment are mentioned, it is clearly limited to a specific number when clearly indicated as essential and in principle. The number is not limited to the specific number except for the case.

  Further, in each of the above embodiments, when referring to the shape, positional relationship, etc. of the component, etc., the shape, unless otherwise specified and in principle limited to a specific shape, positional relationship, etc. It is not limited to the positional relationship or the like.

1 Injector body (first member)
5 Female thread processing machine 6 Male thread processing machine 11 Female thread 12 First seating surface 21 Housing (second member)
61 First chuck 211 Male thread 212 Second seating surface 11a Pilot hole

Claims (3)

The first machining step for forming the female screw (11) and the first seating surface (12) on the first member (1), the male screw (211) screwed to the female screw, and the first seating surface A second fastening step of forming a second seating surface (212) in contact with the second member (21),
Among the radial directions of the female screw, a predetermined specific direction is a female screw reference radial direction,
Of the radial direction of the male screw, when a predetermined specific direction is the male screw reference radial direction,
In the first machining step, the first member is set in a female screw processing machine (5) for processing the female screw, and a pilot hole machining step for machining the pilot hole (11a) and the first seating surface of the female screw. A first seating surface position measuring step for measuring a position of the first seating surface in the female screw axial direction; and a predetermined distance away from the first seating surface in the female screw axial direction and the female screw in the female screw reference radial direction. Comprising a female thread machining step for machining the female thread so that a valley or a mountain is located;
In the second processing step, a second member holding step of holding the second member on a first chuck (61) of a male screw processing machine (6) for processing the male screw, and processing the second seating surface. A second seating surface machining step, a second seating surface position measuring step for measuring a position of the second seating surface in the male screw axial direction, and the distance from the second seating surface in the male screw axial direction to the predetermined distance And a male screw machining step for machining the male screw so that a crest or trough of the male screw is positioned in a screw reference radial direction.   2. The screw fastening component according to claim 1, wherein the second member holding step holds the second member by positioning the second member so that the male screw reference radial direction of the second member faces a predetermined direction. Manufacturing method. The male thread processing machine includes a second chuck (66) for holding the second member,
In the second machining step, after the male screw machining step, the second member is held by the second chuck, and the male screw is placed on the portion of the second member held by the first chuck. The manufacturing method of the screw fastening component of Claim 1 provided with the marking process which provides the mark which shows a reference | standard radial direction.

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