JP2015194469A - Method and apparatus for manufacturing gas sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a gas sensor, capable of manufacturing the gas sensor at a low cost.SOLUTION: A metal holder 29 inserted into the ceramic sensor element of a gas sensor is aligned in a predetermined posture while moving a transfer passage 62 from a part feeder 61, and is aligned and transferred at a vertical posture in the alignment step. A guide rail 63 provided in the transfer passage 62 is contacted with a circumferential direction slit 39 or flange part provided in the holder 29 and is inserted in circumferential direction slit 39. Thereby, the holder 29 is aligned on the guide rail 63. And also a position in the rotational direction of the holder 29 is positioned by the circumferential direction slit 39. The holder 29 and a columnar heater are positioned at a press-fitting start position by dropping either of them.

Description

  The invention disclosed herein relates to a gas sensor manufacturing method and a gas sensor manufacturing apparatus.

  Patent Document 1 discloses a structure of a gas sensor that can be used as an oxygen sensor for an internal combustion engine, and a manufacturing method thereof. In this gas sensor, a holder, which is a metal spring having a C-shaped cross section, is mounted on a ceramic rod-shaped heater. The holder has not only a function of holding the heater but also a function as a terminal for contacting the inner electrode of the cup-shaped sensor element. For this reason, the holder has a complicated shape.

JP 2007-278806 A

  In the gas sensor, it is necessary to suppress breakage of the ceramic heater, and it is necessary to accurately assemble the heater and the metal holder in a predetermined positional relationship. For this reason, efficient mass production is difficult.

  In one aspect, the prior art has one problem in the stage of aligning holders having complicated shapes and supplying them to subsequent assembly processes. In order to realize mass production at a low cost, it is necessary to align the holders efficiently. Specifically, it is necessary to align the posture suitable for the next step. Further, it is necessary to carry the sheet while maintaining a predetermined posture. From this point of view, further improvements are required in the holder alignment process.

  Further, from another viewpoint, the conventional technique has one problem in the stage of connecting the heater and the holder. At this stage, it is necessary to position both in a posture suitable for the subsequent press-fitting process. In addition, in the process of connecting the heater and the holder, it is necessary to take care to prevent the heater from being damaged. From such a viewpoint, further improvement is required for the process of connecting the heater and the holder.

  In the above-mentioned viewpoints or other aspects not mentioned, further improvements are required for the gas sensor manufacturing method and manufacturing apparatus.

  One of the objects of the invention is to provide a gas sensor manufacturing method and a gas sensor manufacturing apparatus that enable low-cost production.

  Another object of the invention is to provide a gas sensor manufacturing method and a gas sensor manufacturing apparatus that enables low-cost production by aligning a holder in a predetermined posture suitable for conveyance.

  Another object of the present invention is to provide a gas sensor manufacturing method and a gas sensor manufacturing apparatus that enable low-cost production by suppressing damage to the heater when the holder contacts the heater. .

  Another object of the invention is to provide a gas sensor manufacturing method and a gas sensor manufacturing apparatus suitable for a process of press-fitting a heater into a holder in a vertical posture.

  The invention disclosed herein employs the following technical means to achieve the above object. Note that the reference numerals in parentheses described in the claims and in this section indicate a corresponding relationship with specific means described in the embodiments described later as one aspect, and limit the technical scope of the invention. Not what you want.

  The invention according to claim 1 is a rod-like sensor element having a cup-shaped sensor element (13), a base end portion provided with a lead (34) for energization, and a tip end portion disposed inside the sensor element. A heater (32), a heater contact portion (35) that is disposed inside the sensor element, contacts the outer peripheral surface of the heater and holds the heater, and a sensor contact portion (37) that contacts an electrode provided on the inner surface of the sensor element And a holder (29) for supporting the heater inside the sensor element, a circumferential slit or flange portion extending along a plane (HP) orthogonal to the central axis (AX) of the holder (39, 929b) is brought into contact with guide rails (63, 867, 868) extending along the conveyance direction of the holder to align the holder and maintain the posture of the holder. A step (142), characterized in that it comprises a gas sensor assembly process (148) to be placed in the sensor element holder.

  In the present invention, the holder is aligned and maintained in a predetermined posture by utilizing a circumferential slit or a flange portion extending along a plane orthogonal to the central axis of the holder. By using the circumferential slit or the flange portion, the holder can be aligned at a predetermined position in a predetermined posture with respect to the axial direction of the holder, and the posture can be maintained. Thereby, a holder can be aligned in the attitude | position suitable for a subsequent process. As a result, efficient heater unit production is possible, and low-cost production is possible.

  The invention according to claim 2 is characterized in that in the aligning step, the holder is aligned in the vertical posture by bringing the circumferential slit or the flange portion into contact with the guide rail. According to the present invention, in the alignment step, the holder can be aligned in a vertical posture suitable for the subsequent steps.

  According to a third aspect of the present invention, the heater contact portion is formed in a C-shaped cross section by the first vertical slit (36) extending along the axial direction, and the sensor contact portion extends along the axial direction. The second longitudinal slit (38) is formed in a C-shaped cross section, and the circumferential slit (39) leaves a connecting portion for connecting the heater contact portion (35) and the sensor contact portion (37). It is provided over an angular range that does not reach 360 degrees along the circumferential direction, and the alignment step is performed by bringing the guide rail into contact with the circumferential slit and / or the first longitudinal slit or the second longitudinal slit. The guide member (65, 365, 466) is brought into contact with the holder to restrict the rotation around the axis of the holder. In this invention, rotation of a holder is controlled using a circumferential slit or a vertical slit. Accordingly, the position around the axis of the holder can be defined based on the circumferential slit or the longitudinal slit in the alignment step, and the holder can be aligned at such a circumferential position.

  The invention according to claim 4 is characterized in that the guide rail (63) is a plate-like member that can be inserted into the circumferential slit, and the guide rail is inserted into the circumferential slit in the alignment step. And In this invention, the guide rail is inserted into the circumferential slit, so that the axial position of the holder is aligned by the guide rail.

  In the invention according to claim 5, the flange portion is formed so as to extend radially outward from the end portion of the holder, and the guide rail (867, 868) has a gap into which the flange portion can be inserted. It is a member to be formed, and in the alignment step, the flange portion is inserted into the gap. In this invention, the axial position of the holder is aligned by the guide rail by inserting the flange portion into the gap formed by the guide rail.

  According to the sixth aspect of the present invention, the holder (29) has a terminal portion (29a) extending in an axial direction to provide an electrical connection, and the guide rail (867, 868) is connected to the sensor contact of the holder. A pair of first guide rails (867) disposed on both sides of the terminal portion and a pair of second guide rails disposed on both sides of the terminal portion and preventing rotation around the axis of the holder by interfering with the terminal portion ( 868), and in the aligning step, the holder is positioned between the pair of first guide rails and the pair of second guide rails. In this invention, rotation of a holder is controlled using the terminal part extended from a holder.

  In the invention according to claim 7, the heater contact portion is formed in a C-shaped cross section by the first vertical slit (36) extending along the axial direction, and the sensor contact portion extends along the axial direction. The second vertical slit (38) is formed into a C-shaped cross section, and the first vertical slit and the second vertical slit are provided apart from each other around the axis of the holder. To do. In the present invention, the rotation of the holder can be suppressed even in a holder that easily generates a rotational force during press-fitting due to the positions of the two vertical slits being separated in the circumferential direction.

  The invention described in claim 8 further includes a dropping step (154) of covering one end of the heater by dropping one of the heater and the holder, and pressing the heater into the holder as a heater unit. And a press-fitting step (156) for assembling. According to the present invention, since the heater and the holder are combined while being held firmly and are combined by one free fall, damage to the heater is suppressed.

  The invention according to claim 9 is characterized in that the dropping step is executed with the heater and the holder positioned in a vertical posture.

  The invention according to claim 10 is a rod-like sensor element having a cup-shaped sensor element (13), a proximal end portion provided with a lead (34) for energization, and a distal end portion disposed inside the sensor element. A heater (32), a heater holding part (35) disposed inside the sensor element, contacting the outer peripheral surface of the heater and holding the heater, and a contact part (37) contacting the electrode provided on the inner surface of the sensor element And a holder (29) for supporting the heater inside the sensor element, the step of holding the heater and the holder in a vertical position (151, 152), and one of the heater and the holder being the other Positioning the top and dropping one of the heater and the holder by its own weight, a dropping step (154) for inserting the leading end of the heater into the holder, and a heating in the holder The press-fit step of assembling a heater unit (156) by press-fitting, characterized in that it comprises a gas sensor assembly process of placing the heater unit in the sensor element (148). According to the present invention, since the heater and the holder are combined while being held firmly and are combined by one free fall, damage to the heater is suppressed.

  In the invention according to claim 11, in the dropping step, one of the heater and the holder separated from the holding device (76, 79) for conveying by holding one of the heater and the holder is suppressed by the guide member, It is characterized by being dropped in the axial direction.

  The invention according to claim 12 is characterized in that one of the heater and the holder falls while being guided by the guide member so as to avoid a collision between the slit edge (39a) of the circumferential slit and the heater.

  The invention according to claim 13 further includes a positioning step in which one of the heater and the holder is positioned by the holding device until the contact portion of the holder covers the tip, although the holder is separated from the heater before the dropping step. (152).

  According to the fourteenth aspect of the present invention, before the dropping step, the holding step (151) for holding the heater in the vertical posture with the base end portion facing down and the tip portion facing up, and in the dropping step, the vertical posture is maintained. By dropping the holder by its own weight from above the held heater, the holder is brought into contact with the tip of the heater by its own weight, and the holder is held in a state of covering the heater.

  The invention according to claim 15 is a rod-like sensor element having a cup-shaped sensor element (13), a base end portion provided with a lead (34) for energization, and a tip end portion disposed inside the sensor element. A heater (32), a heater contact portion (35) that is disposed inside the sensor element, contacts the outer peripheral surface of the heater and holds the heater, and a sensor contact portion (37) that contacts an electrode provided on the inner surface of the sensor element And a holder (29) for supporting the heater inside the sensor element in a gas sensor manufacturing apparatus, the guide rail extending along the carrying direction of the holder and orthogonal to the central axis (AX) of the holder A guide rail (63) which aligns the holder by contacting a circumferential slit or flange (39, 829b) extending along the plane (HP) and maintains the posture of the holder Characterized in that it comprises a 867,868). In this invention, the guide rail which aligns a holder and maintains an attitude | position is provided. The guide rail uses a circumferential slit or a flange portion extending along a plane orthogonal to the central axis of the holder to align the holder and maintain it in a predetermined posture.

  The invention described in claim 16 is characterized in that the guide rail (63) is a plate-like member that can be inserted into the circumferential slit. In this invention, the guide rail is inserted into the circumferential slit, so that the axial position of the holder is aligned by the guide rail.

  In the invention described in claim 17, the flange portion is formed so as to extend radially outward from the end portion of the holder, and the guide rail (867, 868) has a gap into which the flange portion can be inserted. It is a member to be formed. In this invention, the axial position of the holder is aligned by the guide rail by inserting the flange portion into the gap formed by the guide rail.

  According to the present invention, the holder (29) has a terminal portion (29a) extending in an axial direction to provide an electrical connection, and the guide rail (867, 868) is connected to the sensor contact of the holder. A pair of first guide rails (867) disposed on both sides of the terminal portion and a pair of second guide rails disposed on both sides of the terminal portion and preventing rotation around the axis of the holder by interfering with the terminal portion ( 868). In this invention, rotation of a holder is controlled using the terminal part extended from a holder.

  The invention according to claim 19 is a rod-like sensor element having a cup-shaped sensor element (13), a proximal end portion provided with a lead (34) for energization, and a distal end portion disposed inside the sensor element. A heater (32), a heater holding part (35) disposed inside the sensor element, contacting the outer peripheral surface of the heater and holding the heater, and a contact part (37) contacting the electrode provided on the inner surface of the sensor element And a holder (29) for supporting the heater inside the sensor element, the heater and the holder are held in a vertical posture in which the tip of the heater can be inserted into the holder, and the heater and An upper holding device (76, 79) and a lower holding device (71, 72, 73, 74, 77) for positioning one of the holders on the other, and a heater tip inside the holder After marked location, characterized in that it comprises a control device for opening the upper holding device so as to fall by its own weight while the heater and the holder (70). According to the present invention, since the heater and the holder are combined while being held firmly and are combined by one free fall, damage to the heater is suppressed.

  The invention according to claim 20 is characterized in that the control device causes the guide member to drop one of the heater and the holder separated from the upper holding device in the axial direction. According to this invention, the collision between the heater and the holder is suppressed.

It is sectional drawing of the gas sensor which concerns on 1st Embodiment of invention. It is a flowchart which shows the manufacturing method of a gas sensor. It is sectional drawing which shows the feeder in the alignment process of 1st Embodiment. It is a side view which shows the alignment process of 1st Embodiment. It is sectional drawing which shows the alignment process of 1st Embodiment. It is sectional drawing which shows the alignment process of 1st Embodiment. It is sectional drawing which shows the alignment process of 1st Embodiment. It is a bottom view which shows the alignment process of 1st Embodiment. It is sectional drawing which shows the alignment process of 2nd Embodiment of invention. It is a bottom view which shows the alignment process of 2nd Embodiment. It is sectional drawing which shows the alignment process of 2nd Embodiment. It is sectional drawing which shows the alignment process of 3rd Embodiment of invention. It is sectional drawing which shows the alignment process of 4th Embodiment of invention. It is sectional drawing which shows the alignment process of 5th Embodiment of invention. It is sectional drawing which shows the alignment process of 6th Embodiment of invention. It is sectional drawing which shows the alignment process of 7th Embodiment of invention. It is a side view which shows the alignment process of 8th Embodiment of invention. It is a bottom view which shows the alignment process of 8th Embodiment. It is a side view which shows the alignment process of 9th Embodiment of invention. It is sectional drawing which shows the alignment process of 10th Embodiment of invention. It is a flowchart which shows the manufacturing method of the gas sensor of 11th Embodiment of invention. It is a transition diagram which shows the holder mounting process of 11th Embodiment. It is a transition diagram which shows the holder mounting process of 11th Embodiment. It is sectional drawing which shows the chuck | zipper for holders of 11th Embodiment. It is sectional drawing which shows the chuck | zipper for holders of 11th Embodiment. It is sectional drawing which shows the relationship between the holder and heater of 11th Embodiment. It is sectional drawing which shows the relationship between the holder and heater of 11th Embodiment. It is a transition diagram which shows the holder mounting process of 12th Embodiment of invention.

  A plurality of modes for carrying out the invention disclosed herein will be described with reference to the drawings. In each embodiment, portions corresponding to the matters described in the preceding embodiment may be denoted by the same reference numerals and redundant description may be omitted. Further, in the following embodiments, the correspondence corresponding to the matters corresponding to the matters described in the preceding embodiments is indicated by adding reference numerals that differ only by one hundred or more, and redundant description may be omitted. . In each embodiment, when only a part of the structure is described, the other parts of the structure can be applied with reference to the description of the other forms.

(First embodiment)
(Configuration of gas sensor)
In FIG. 1, a longitudinal section of a gas sensor 10 of this embodiment is shown. The gas sensor 10 is attached to an exhaust passage of an internal combustion engine or the like, and can be used as an oxygen sensor that measures the oxygen concentration in the exhaust gas. The gas sensor 10 includes a sensor unit 11 and a wiring unit 12. The sensor unit 11 outputs an electrical signal resulting from an electrochemical reaction caused by a specific gas component. The wiring unit 12 provides power supply for causing the sensor unit 11 to function and electrical connection for extracting an electrical signal output from the sensor unit 11.

  The sensor unit 11 includes a sensor element 13. The sensor element 13 is a cup-shaped member made of a solid electrolyte. As the solid electrolyte, zirconia ceramics can be used. The sensor element 13 has a porous electrode on each of an inner surface and an outer surface. The sensor element 13 generates an electromotive force according to the difference in oxygen concentration between the inside and the outside, and this electromotive force is detected from the porous electrode.

  The housing body 14 holds the sensor element 13 and has a shape suitable for mounting in a passage through which a gas to be measured flows. The housing body 14 is made of stainless steel. In the following description, members not specifically mentioned are made of metal such as stainless steel and iron. The sensor element 13 is inserted and held in the housing body 14. A fireproof sealing material 15 is disposed between the sensor element 13 and the housing body 14. Further, a retainer ring 16 and a spacer ring 17 are accommodated between the sensor element 13 and the housing body 14.

  The sensor element 13 is disposed so as to protrude from the distal end portion of the housing body 14 into a cylindrical shape with the distal end closed. An inner cover 18 and an outer cover 19 for protecting the sensor element 13 are fixed to the housing body 14. The inner cover 18 and the outer cover 19 are provided with a large number of communication holes so that the gas reaches the outside of the sensor element 13.

  The open end of the sensor element 13 is positioned at the rear end of the housing body 14. A wiring portion 12 is connected to the rear end of the housing body 14. The wiring part 12 has a cylindrical rear cover 21. One end of the rear cover 21 is connected to the housing body 14. An insulator 22 for holding electric wiring is disposed in the rear cover 21. The insulator 22 is made of an electrically insulating ceramic. A rubber grommet 23 is disposed at the rear end of the rear cover 21. The grommet 23 holds a plurality of wires 24, 25, and 26 coated with resin.

  A first sensor terminal 28 is disposed inside the rear cover 21. The first sensor terminal 28 is a metal terminal that contacts a porous electrode formed on the outer peripheral surface of the sensor element 13. The first sensor terminal 28 has a C-shaped contact portion that is press-fitted into the outer peripheral surface of the sensor element 13, and a terminal portion that extends from the contact portion. The terminal portion extends into the insulator 22. The first sensor terminal 28 is connected to the wire 24 by a relay terminal in the insulator 22.

  A second sensor terminal 29 is disposed inside the rear cover 21. The second sensor terminal 29 is a metal terminal that comes into contact with the porous electrode formed on the inner peripheral surface of the sensor element 13. The second sensor terminal 29 includes a C-shaped contact portion that is press-fitted into the inner peripheral surface of the sensor element 13, and a terminal portion that extends from the contact portion. The terminal portion extends into the insulator 22. The second sensor terminal 29 is connected to the wire 25 by a relay terminal in the insulator 22. The second sensor terminal 29 is also called a holder 29 because it has a function of holding a heater 32 described later.

  The gas sensor 10 has a heater unit 31. The heater unit 31 is disposed in the sensor element 13 in order to heat the sensor element 13 to a predetermined activation temperature. The heater unit 31 includes a heater 32 and the holder 29. The holder 29 positions the heater 32 at a predetermined position in the sensor element 13 and holds it at that position.

  The heater 32 is made of an elongated rod-shaped alumina. The heater 32 has a central axis AX extending in the longitudinal direction. The axial direction refers to a direction parallel to the central axis AX of the heater 32. Further, the circumferential direction indicates a circumferential direction around the central axis AX of the heater 32. The heater 32 functions as a positive temperature characteristic (PTC) heater element. The tip of the heater 32 is inserted into the sensor element 13. The rear end portion of the heater 32 is disposed so as to protrude from the opening end of the sensor element 13 by a predetermined length. A pair of heater terminals 33 for supplying power are provided at the rear end of the heater 32. The heater terminals 33 are arranged on the outer peripheral surface of the columnar heater 32 so as to be separated from each other. The pair of heater terminals 33 are arranged apart from each other on the diameter of the outer peripheral surface of the heater 32. Only one heater terminal 33 is shown in the figure.

  A lead 34 made of nickel alloy is brazed to the heater terminal 33. The heater 32 is provided with a pair of leads 34. The two leads 34 are arranged on a diameter passing through the central axis AX of the heater 32. The lead 34 protrudes from the heater 32 and extends along the longitudinal direction of the heater 32. The lead 34 is in contact with the outer peripheral surface of the heater 32 on the heater terminal 33. The lead 34 extends from the outer peripheral surface of the heater 32 slightly outward in the radial direction while extending along the axial direction of the heater 32 and a portion extending obliquely along the axial direction of the heater 32. And have. The two leads 34 extend into the insulator 22. The two leads 34 are respectively connected to different relay terminals in the insulator 22. These relay terminals are connected to wires. In the figure, only one wire 26 of the two wires is shown. As a result, the heater 32 has a proximal end portion provided with a lead 34 for energization and a distal end portion disposed inside the sensor element.

  The holder 29 is made of metal such as spring steel. The holder 29 is substantially cylindrical. The holder 29 has a central axis AX that coincides with the central axis AX of the heater 32. The axial direction refers to the direction of the central axis AX of the holder 29. The circumferential direction refers to the circumferential direction around the center axis AX of the holder 29. The holder 29 is disposed inside the sensor element 13. The holder 29 has a heater contact portion 35 that holds the heater 32 by contacting the outer peripheral surface of the heater 32. In the following description, the heater contact portion 35 is also referred to as a heater holding portion 35. The holder 29 has a sensor contact portion 37 that is press-fitted into the inner peripheral surface of the sensor element 13, contacts the inner surface of the sensor element 13, and is fixed in the sensor element 13. The sensor contact portion 37 is also a contact portion 37 that provides an electrical connection by contacting an electrode provided on the inner surface of the sensor element 13. In the following description, the sensor contact portion 37 is referred to as a contact portion 37. The holder 29 supports the heater 32 inside the sensor element 13.

  The heater holding part 35 is a cylindrical part having a C-shaped cross section. The heater holding part 35 has a slit 36 which is an opening extending elongated along the axial direction. The slit 36 is also referred to as a first vertical slit 36. The heater holding portion 35 is elastically deformed and extends radially outward, and is in strong contact with the outer peripheral surface of the heater 32.

  The contact portion 37 is a cylindrical portion having a C-shaped cross section. The contact portion 37 has a slit 38 that is an opening extending elongated along the axial direction. The slit 38 is also referred to as a second vertical slit 38. The contact portion 37 is elastically deformed and contracts radially inward, and is in strong contact with the inner peripheral surface of the sensor element 13.

  The outer diameter of the contact part 37 is larger than the outer diameter of the heater holding part 35. The inner diameter of the heater holding part 35 is smaller than the inner diameter of the contact part 37. The heater holding portion 35 and the contact portion 37 are connected by a tapered cone portion. The heater holding part 35 is provided on the tip side from the contact part 37. As a result, the holder 29 is held on the inner peripheral surface of the sensor element 13 at the opening end of the sensor element 13, and the holder 29 holds the heater 32 on the back side from the opening end of the sensor element 13.

  A circumferential slit 39 extending along the circumferential direction of the holder 29 is provided between the heater holding portion 35 and the contact portion 37. The circumferential slit 39 is formed so as to leave a connecting portion for connecting the heater holding portion 35 and the contact portion 37 without completely making a round of the holder 29. The circumferential slit 39 is provided over an angular range that exceeds 180 degrees but does not reach 360 degrees along the circumferential direction so as to leave a connecting portion that connects the heater holding portion 35 and the contact portion 37. The width of the circumferential slit 39, that is, the width in the axial direction is substantially equal to the width of the slits 36, 38, that is, the width in the circumferential direction. The width of the circumferential slit 39 may be set larger than the width of the slits 36 and 38. The width of the circumferential slit 39 may be set smaller than the width of the slits 36 and 38.

  The circumferential slit 39 provides a C-shaped edge extending along a plane HP orthogonal to the central axis AX of the holder 29. This edge is used to define the axial position of the holder 29. Both ends of the circumferential slit 39, that is, the two innermost ends along the circumferential direction of the circumferential slit 39 define a straight line passing through a plane orthogonal to the central axis AX but positioned away from the central axis AX. Both ends of the circumferential slit 39 are used to restrict the rotation of the holder 29 around the central axis AX of the holder 29.

  The holder 29 has a terminal portion 29 a that extends from the rear end of the contact portion 37. The terminal portion 29a extends in the axial direction to provide an electrical connection. The terminal portion 29a has a narrow plate shape corresponding to only a part of the contact portion 37 having a C-shaped cross section. The terminal portion 29 a extends slightly outward in the radial direction from the contact portion 37, and then extends away from the contact portion 37 in the axial direction.

  At the rear end of the contact portion 37, a flare-shaped flange portion 29b that extends outward in the radial direction is provided. The flange portion 29 b functions as a stopper that restricts the amount of insertion of the holder 29 into the sensor element 13. The flange portion 29 b also functions as an operation portion for press-fitting the holder 29 into the heater 32.

  In the illustrated example, the slit 38 and the terminal portion 29 a are located on the opposite sides with respect to the circumferential direction of the holder 29. In other words, the slit 38 and the terminal portion 29a are located on the opposite sides in diameter. The slit 36 and the slit 38 are provided at different angular positions with respect to the circumferential direction of the holder 29. In the example shown in the figure, the slit 36 and the slit 38 are arranged so as to be shifted by approximately 90 degrees. The circumferential slit 39 extends from the slit 38 for the contact portion 37 over substantially the same angular range toward both sides in the circumferential direction. Due to the difference between the slit 36 and the slit 38, the circumferential slit 39 extends over an asymmetrical angular range with respect to the slit 36.

(Gas sensor manufacturing method)
In FIG. 2, a plurality of steps showing a method for manufacturing the gas sensor 10 are illustrated. The gas sensor manufacturing method includes steps 141 to 143 for supplying the holder 29 and steps 145 to 146 for supplying the heater 32. Further, the gas sensor manufacturing method includes a gas sensor assembly step 148 for assembling the gas sensor 10 using the holder 29 and the heater 32 as parts of the gas sensor 10. In the assembly process 148, the heater 32 is press-fitted into the holder 29, and the heater unit 31 is assembled.

  Step 141 is a supply process. Here, a plurality of holders 29 preliminarily molded into a predetermined shape are supplied. The holder 29 is supplied to, for example, a vibration type part feeder.

  Step 142 is an alignment process. In the following description, the operation of moving the holder 29 to a predetermined posture and maintaining the posture is referred to as alignment. The alignment process can include movement of the holder 29. Here, the holders 29 are aligned by selecting the holders 29 in a predetermined posture from the many holders 29. Here, the holder 29 in a predetermined posture is taken out by the parts feeder and held in that posture. Here, the holder 29 is positioned in a vertical posture in which the axial direction is vertical, that is, the axial direction is parallel to the direction of gravity. The holder 29 in the vertical posture makes it easy to chuck the holder 29 in the vertical posture in the subsequent transport process. Furthermore, the holder 29 is aligned so that the terminal portion 29a is located at a predetermined position in the circumferential direction. This circumferential position also facilitates positioning of the holder 29 in subsequent steps.

  In the aligning step, only the holder 29 in a predetermined posture is selected by the parts feeder from the plurality of holders 29 supplied to the parts feeder in a disordered posture. The alignment step includes a step of moving the holder 29 to a predetermined posture while moving the holder 29.

  The aligning step may include a step of aligning the holder 29 along the longitudinal direction of the passage by a narrow groove-like passage provided along the outer periphery of the parts feeder. The step in the passage may include a step of positioning the holder 29 with respect to the circumferential direction by utilizing the engagement between the longitudinal slit 38 of the holder 29 and the guide rail. In this step, the holder 29 is positioned so that the slit 38 is oriented in any one of up, down, left and right directions. In this step, the holder 29 is aligned and the posture of the holder 29 is maintained by bringing the vertical slit 38 and the guide rail 62a into contact with each other and fitting together. The step in the passage may include a step of dropping the holder 29 into a narrow and deep groove and fitting the holder 29 into the groove after the step of using the slit 38. The groove used here is a narrow, deep groove in which the holder 29 is fitted in a vertical posture with the contact portion 37 positioned upward and the heater holding portion 35 positioned downward, and the holder 29 is caught by the thick portion. is there.

  The alignment step can include a step of positioning the holder 29 with respect to the circumferential direction by rotating the holder 29 positioned in the vertical posture in the circumferential direction. This step can include the step of utilizing an edge of the holder 29 that defines a line that is perpendicular to the central axis AX of the holder 29 but does not intersect the central axis AX. The edge is provided by any one or more of the slits 36, 38, 39. In a typical example, the alignment step includes a step of rotating the holder 29 in the circumferential direction by using the circumferential slit 39. In this step, a guide rail 63 that fits in the circumferential slit 39 is used. The fitting of the circumferential slit 39 and the guide rail 63 also provides a step for positioning the holder 29 in the axial direction. In this step, the circumferential slit 39 and the guide rail 63 are brought into contact with each other and fitted to each other, whereby the holder 29 is aligned and the posture of the holder 29 is maintained.

  Step 143 is a transport process. Here, the holder 29 aligned in a predetermined posture is transported to the subsequent process by the transport device. Various devices such as an articulated robot and a SCARA robot can be used as the transfer device. Further, the transport device positions the terminal portion 29a at a predetermined position in the circumferential direction.

  Step 145 is a process for supplying the heater 32. Here, the heater 32 is supplied in a state of being arranged in a predetermined posture on a dedicated pallet.

  Step 146 is a transfer process of the heater 32. Here, the heater 32 is transported to the subsequent process by the transport device. Various devices such as an articulated robot and a SCARA robot can be used as the transfer device.

  Step 148 is an assembly process of the gas sensor 10. This assembly process includes a process of arranging the holder 29 and the heater 32 in the sensor element 13. In one form, after the heater 32 is press-fitted into the holder 29 and the heater unit 31 is assembled, the heater unit 31 is press-fitted into the sensor element 13 and fixed. Alternatively, the heater unit 31 may be assembled in the sensor element 13 by pressing the holder 29 into the sensor element 13 and then pressing the heater 32 into the holder 29. The gas sensor 10 is manufactured by the manufacturing method described above.

(Holder alignment process)
FIG. 3 is a schematic cross-sectional view showing an alignment process for aligning the holder 29. In the figure, a vibration-type parts feeder 61, a large number of holders 29 supplied into the bowl, and a large number of holders 29 that come out of alignment from the parts feeder 61 are schematically shown. The parts feeder 61 arranges the holders 29 in a horizontal posture. The conveyance path 62 of the parts feeder 61 moves the holder 29 in the conveyance direction TD. The conveyance path 62 is a path for carrying the holder 29 out of the parts feeder 61.

  The parts feeder 61 selects only the holder 29 in a predetermined attitude from the plurality of holders 29 supplied to the parts feeder 61 in a disordered attitude. The parts feeder 61 includes a selection unit that sifts out the holder 29 that is not in a predetermined posture, and a correction unit that moves the holder 29 to a predetermined posture while moving the holder 29. The parts feeder 61 is provided along the outer periphery thereof, and has a thin groove-shaped conveyance passage 62 extending from a predetermined position in a tangential direction or a radial direction. The conveyance path 62 provides a selection unit and a correction unit.

  As shown in FIG. 3, in the initial portion of the transport passage 62, only the holder 29 that is in the posture along the longitudinal direction of the transport passage 62 is placed on the transport passage 62, and the holder 29 that is not in that posture is sieved off. The starting end portion provides a first sorting portion.

  As shown in FIG. 3, the middle part of the transport passage 62 has a guide rail 62 a provided on the wall surface of the transport passage 62. The guide rail 62 a is a plate-like member that extends along the longitudinal direction of the transport passage 62 and extends upward from the bottom surface of the transport passage 62. The guide rail 62a can also be referred to as a vertical guide rail 62a. The guide rail 62 a is provided so as to gradually increase from the wall surface of the transport passage 62 from the start end to the end of the transport passage 62. The guide rail 62 a is a plate-like member having a thickness that fits with the longitudinal slit 38 of the holder 29. As illustrated, the guide rail 62 a can be provided on the bottom surface of the transport passage 62. The holder 29 in such a posture that the slit 38 does not fit into the guide rail 62 a rides on the guide rail 62 a and is sieved off from the transport passage 62. The holder 29 in a posture in which the slit 38 is fitted in the guide rail 62a moves while meshing with the guide rail 62a. Therefore, the middle portion having the guide rail 62a provides a second sorting section. Further, some of the holders 29 rotate so as to shift from an incomplete fitting state between the slit 38 and the guide rail 62a to a complete fitting state. Therefore, it can be said that the middle part having the guide rail 62a provides the first correction part. FIG. 4 shows a fitted state between the slit 38 and the guide rail 62a.

  Returning to FIG. 3, the guide rail 62 a is interrupted in the middle of the conveyance path 62. A transition portion where the shape of the conveyance path 62 changes from a shallow groove to a deep groove is provided in the middle part of the conveyance path 62 where the end of the guide rail 62a is positioned. The conveyance path 62 has a guide rail 62b that defines a narrow and deep groove. The thin and deep groove provided after the conversion portion is fitted in a vertical posture in which the holder 29 positions the contact portion 37 on the upper side and the heater holding portion 35 on the lower side, and the holder 29 has a thick portion or a flange portion 29b. It has a width that can be caught by and suspended.

  The shallow groove to the turning portion positions the holder 29 in the horizontal posture and moves it in the horizontal posture. In the conversion portion, the holder 29 is dropped from the guide rail 62a toward the narrow and deep groove. The holder 29 is fitted in this groove and is suspended by the corner portion of the guide rail 62b that defines the groove. The deep groove after the turning portion positions the holder 29 in the vertical position and moves it in the vertical position. In the turning portion, the holder 29 in a posture in which the heater holding portion 35 thinner than the contact portion 37 is positioned forward in the traveling direction falls from the heater holding portion 35 into a narrow and deep groove and fits into the groove. The holder 29 in a posture not to fit in the groove at the conversion portion is sieved off from the transport passage 62. Thus, the conversion part provides a third sorting part.

  As shown in FIG. 3, the final portion of the transport passage 62 has a guide rail 63 provided on the wall surface of the transport passage 62. The guide rail 63 extends along the conveyance direction of the holder 29. The guide rail 63 is a plate-like member that extends along the longitudinal direction of the transport passage 62 and extends from the side surface of the transport passage 62 in the lateral direction, more specifically, slightly inclined with respect to the horizontal direction. The guide rail 63 can also be referred to as a lateral guide rail 63. As illustrated, the guide rail 63 can be provided on the side surface of the transport passage 62. The guide rail 63 is provided so as to gradually increase from the wall surface of the transport passage 62 from the start end to the end of the transport passage 62. The guide rail 63 is a metal elongated plate extending along the length direction of the transport passage 62. The guide rail 63 is a plate-like member that can be inserted into the circumferential slit 39.

  In the alignment step, the guide rail 63 is inserted into the circumferential slit 39. The guide rail 63 is provided in the conveyance path so as to enter the circumferential slit 39 of the holder 29 aligned with the conveyance path 62. The guide rail 63 is disposed so as to gradually rise from the wall of the conveyance path as the conveyance path advances. As a result, the guide rail 63 gradually enters the circumferential slit 39 as the holder 29 moves through the conveyance path. Some of the holders 29 rotate so as to shift from an incompletely fitted state to a completely fitted state due to interference between the circumferential slit 39 and the guide rail 63. Therefore, the final part having the guide rail 63 provides a second correction part. As a result, the holder 29 moves while being engaged with the guide rail 63. The guide rail 63 is engaged with the circumferential slit 39 to restrict the rotation of the holder 29 in the circumferential direction.

  The terminal portion 29 a and the circumferential slit 39 are provided so as to be positioned at a predetermined angular position with respect to the circumferential direction of the holder 29. Therefore, the holder 29 on the guide rail 63 is aligned by positioning the terminal portion 29a at a predetermined position. As a result, the holder 29 is positioned so that both the vertical posture and the circumferential posture are in a prescribed posture.

  5, 6, and 7 show cross sections orthogonal to the longitudinal direction of the conveyance passage 62. From the middle part to the end part of the conveyance path 62, the conveyance path 62 holds the holder 29 in a slightly inclined vertical posture.

  The conveyance path 62 has a guide member 64 positioned on the upper side of the holder 29. The guide member 64 defines the position of the holder 29 in the axial direction by coming into contact with a step portion provided in the holder 29. In the illustrated example, the guide member 64 is positioned below the step provided in the terminal portion 29a and supports the step from below. The guide member 64 maintains the posture of the holder 29 in the axial direction. The guide member 64 is also a part of the guide rail 62b.

  The conveyance path 62 has a guide member 65 positioned on the lower side of the holder 29. The guide member 65 contacts an opening provided by the slit 38. Two edges that are spaced apart in the circumferential direction so as to define the slit 38 are located on one plane. The guide member 65 controls the rotation of the holder 29 by contacting these two edges, and maintains the posture of the holder 29 in the circumferential direction. The guide member 65 is also a part of the guide rail 62b.

  As shown in FIG. 5, in the initial stage of the conveyance path 62, the guide rail 63 hardly enters or slightly enters the circumferential slit 39. As shown in FIG. 6, when the holder 29 advances through the conveyance path 62, the guide rail 63 enters deeply into the circumferential slit 39. In this manner, the guide rail 63 gradually enters the circumferential slit 39 as the holder 29 advances in the conveyance path 62.

  At this time, the guide rail 63 lifts and supports the holder 29 by the circumferential slit 39. In other words, the holder 29 is on the guide rail 63. The holder 29 is stocked until it is conveyed to the subsequent process while maintaining the vertical posture. The holder 29 may be held in a complete vertical posture as shown in FIG.

  FIG. 8 is a bottom view of FIG. 7 viewed from below. As shown in the figure, the guide rail 63 enters the circumferential slit 39 beyond half of the holder 29 in the radial direction. The holder 29 is maintained in a vertical posture by the guide rail 63, the guide member 64, and the guide member 65. Furthermore, the holder 29 is maintained in a predetermined posture with respect to the circumferential direction by the guide rail 63 and the guide member 65. The guide rail 63 provides a regulating member that regulates rotation of the holder 29 in the circumferential direction by meshing with the circumferential slit 39.

  The guide member 65 provides a regulating member that regulates rotation of the holder 29 in the circumferential direction by meshing with the slit 38. The guide member 65 prevents the holder 29 from rotating in the circumferential direction even when the engagement between the circumferential slit 39 and the guide rail 63 is eliminated. Thereby, even after the guide rail 63 is extracted from the circumferential slit 39, the holder 29 is positioned at a predetermined position in the circumferential direction.

  According to this embodiment, a gas sensor manufacturing method and a gas sensor manufacturing apparatus capable of low-cost production are provided. In addition, stable quality can be provided. In this embodiment, in the step of aligning the holder 29, the holder 29 can be aligned in a vertical posture suitable for conveyance. Further, the holder 29 can be aligned in a vertical posture suitable for the subsequent process. For example, the vertical posture may be suitable for gripping (chuck operation) for conveyance to a subsequent process. Further, the vertical posture may be transferred to the subsequent process as it is.

  Moreover, the holder 29 can be aligned in the circumferential direction so that the position of the terminal portion 29a of the holder 29 is a predetermined position. As a result, low-cost production is possible. Specifically, the holder 29 can be stably aligned in the vertical posture by the guide rail 63 that meshes with the circumferential slit 39. In addition, the guide rail 63 aligns the holder 29 in the circumferential direction. Circumferential alignment is also provided by the guide member 65.

(Second Embodiment)
This embodiment is a modification based on the preceding embodiment. In the holder 29 of the above-described embodiment, the slit 36 and the slit 38 are provided at angular positions different by 90 degrees. The positions of the slit 36 and the slit 38 can be positioned in various combinations.

  In this embodiment illustrated in FIGS. 9, 10, and 11, the slit 236 that forms the heater holding portion 35 and the slit 38 that forms the contact portion 37 are formed at the same position in the circumferential direction. . Also in this embodiment, the guide member 65 prevents the holder 29 from rotating in the circumferential direction by contacting the edge of the slit 38.

(Third embodiment)
This embodiment is a modification based on the preceding embodiment. In the above embodiment, the rotation of the holder 29 in the circumferential direction is prevented by the slit 38 and the guide member 65. Instead of this, rotation of the holder 29 in the circumferential direction may be prevented by the slit 236 forming the heater holding portion 35.

  In the embodiment illustrated in FIG. 12, the rotation of the holder 29 is prevented by the slit 236 that forms the heater holding portion 35 and the guide member 365 of the transport passage 62. In this way, the rotation prevention of the holder 29 in the transport process can be realized by using the slits 38 and 236 that spread along a plane parallel to the transport direction TD.

(Fourth embodiment)
This embodiment is a modification based on the preceding embodiment. In the above embodiment, the circumferential rotation of the holder 29 is prevented by the slits 38 and 236 that define a plane parallel to the transport direction TD. Alternatively, rotation of the holder 29 in the circumferential direction may be prevented by a slit that divides a plane orthogonal to the transport direction TD.

  In the embodiment illustrated in FIG. 13, the rotation of the holder 29 in the circumferential direction is prevented by applying the slit 36 to the end wall 466 at the end of the transport direction TD. According to this embodiment, the circumferential position of the holder 29 can be positioned at a predetermined position at the end of the alignment process, that is, immediately before being transported by the transport device.

(Fifth embodiment)
This embodiment is a modification based on the preceding embodiment. In the above-described embodiment, the holder 29 is transported in an upright vertical posture along the direction of gravity in the alignment step. Instead of this, the holder 29 may be transported in a slightly inclined vertical posture.

  In the embodiment illustrated in FIG. 14, the holder 29 is conveyed in a slightly inclined vertical posture. The holder 29 is inclined so that the circumferential slit 39 faces downward. In other words, the holder 29 is tilted so that the terminal portion 29a is positioned on the upper side.

(Sixth embodiment)
This embodiment is a modification based on the preceding embodiment. In the embodiment illustrated in FIG. 15, the guide member 64 positioned on the upper side of the holder 29 that is conveyed while being inclined is removed. The holder 29 is transported while riding on the guide rail 63 and the guide member 65 by its own weight. Therefore, the guide member 64 located on the upper side can be eliminated.

(Seventh embodiment)
This embodiment is a modification based on the preceding embodiment. In the embodiment illustrated in FIG. 16, both guide members 64, 65 have been removed. The holder 29 is transported while riding on the guide rail 63 by its own weight. The guide rail 63 alone can maintain the posture of the holder 29.

(Eighth embodiment)
This embodiment is a modification based on the preceding embodiment. The holder 29 of the above embodiment has a flange portion 29b having a relatively narrow width. The holder 29 can have variously shaped flange portions.

  In the embodiment shown in FIGS. 17 and 18, the holder 29 has a flange portion 829 b formed so as to extend long from the end portion thereof toward the radially outer side. The flange portion 829b includes plate pieces that can be called four tab shapes. The flange portion 829b is provided at the end portion of the contact portion 37 so as to extend outward in the radial direction. The flange portion 829 b extends along a plane HP orthogonal to the center axis AX of the holder 29.

  In this embodiment, the conveyance path 62 of the parts feeder 61 includes a pair of left and right guide rails 867 and a pair of left and right guide rails 868. These guide rails 867 and 868 extend in a plate shape.

  As illustrated in FIG. 17, the holder 29 is introduced between the guide rails 867 and 868. The guide rails 867 and 868 are members that form gaps or grooves into which the flange portion 829b can be inserted. The gap can also be called a slot. In the alignment step, the flange portion 829b is inserted into the gap. The holder 29 is conveyed between the guide rails 867 and 868 while maintaining a vertical posture. A gap in which the flange portion 829b can be disposed is formed between the guide rail 867 and the guide rail 868 in the vertical direction. It is desirable that the vertical gap L between the guide rail 867 and the guide rail 868 and the thickness T of the flange portion 829b be set so as to satisfy L <2T. The flange portion 829b can slide between the guide rail 867 and the guide rail 868 and move.

  As shown in FIG. 18, the pair of lower guide rails 867 are located on both sides of the contact portion 37 of the holder 29. The pair of lower guide rails 867 form a groove-like gap that can receive the contact portion 37 of the holder 29 therebetween. The pair of upper guide rails 868 are located on both sides of the holder 29. The pair of upper guide rails 868 form a groove-like gap that can receive the terminal portion 29a of the holder 29 therebetween. This gap is a narrow gap that restricts movement of the terminal portion 29a and restricts rotation of the holder 29 in the circumferential direction. The pair of upper guide rails 868 are disposed on both sides of the terminal portion 29a. In the alignment process, the holder 29 is positioned between the pair of first guide rails 867 and between the pair of second guide rails 868.

  In this embodiment, instead of the circumferential slit 39 of the above embodiment, a relatively large flange portion 829b is used as a surface for positioning the holder 29 in a vertical posture. In the alignment step 142, the holder 29 is aligned in the vertical posture by bringing the flange portion 829b into contact with the guide rails 867 and 868. Also in this embodiment, the rotation of the holder 29 in the circumferential direction can be prevented in the alignment step.

(Ninth embodiment)
This embodiment is a modification based on the preceding embodiment. Instead of the above-described embodiment, slits 236 and 38 extending in the vertical direction may be used at any stage of the alignment process.

  The embodiment illustrated in FIG. 19 utilizes the slits 236, 38 of the holder 29 illustrated in FIG. The guide rail 962 a meshes with both the slit 236 and the slit 38 of the holder 29.

(10th Embodiment)
This embodiment is a modification based on the preceding embodiment. Instead of the above embodiment, a holder without the terminal portion 29a may be adopted. FIG. 20 illustrates a holder 29 having no terminal portion. The holder 29 is connected to an electric wire or bus bar corresponding to the terminal portion 29a.

(Eleventh embodiment)
This embodiment is a modification based on the preceding embodiment. In addition to the above embodiment, a new process for combining the heater 32 and the holder 29 can be employed. FIG. 21 is a flowchart showing a method for manufacturing the gas sensor of this embodiment. In this embodiment, a mounting process 150 for forming the heater unit 31 by combining the holder 29 and the heater 32 is employed. In the mounting step 150, the holder 29 is positioned at the tip of the heater 32 by dropping the holder 29 from above the heater 32.

  In this embodiment, steps 141-146 of the preceding embodiment are employed. Step 151 is a heater installation process in which the heater 32 is installed in a predetermined posture. Here, the heater 32 is positioned on the work table so as to assume a predetermined posture by the transfer device. Here, the heater 32 is positioned in an upside-down vertical posture with the tip end up and the lead 34 down. The heater 32 is positioned so that its central axis AX is parallel to the direction of gravity. Step 151 provides a holding step of holding the heater 32 in a vertical posture with the base end facing down and the tip end facing up. Here, the central part of the heater 32 is slightly tightened by a holding device provided on the work table. The holding device includes a chuck device capable of holding or releasing the member. The chuck device can hold a member by a movable claw portion. Thereby, the heater 32 is adjusted to an inverted vertical posture.

  Step 152 is a positioning process. Here, the holder 29 is positioned on the heater 32 by the transport device. The holder 29 is positioned in an inverted vertical posture with the contact portion 37 positioned downward and the heater holding portion 35 positioned upward on the heater 32 held with the tip positioned upward. That is, the holder 29 is positioned so as to cover the top of the heater 32. In this positioning step, the holder 29 is separated from the heater 32, but the holder 29 can be positioned by the holding device to a position where the contact portion 37 of the holder 29 covers the tip of the heater 32.

  The transport device transports the holder 29 while detecting the interference with other articles while transporting the holder 29. For example, when a torque equal to or greater than a predetermined threshold is generated, the transfer device detects interference and notifies the operator.

  Step 153 is a gap chucking process for loosening the chuck device included in the holding device of the transport device. The chuck device is slightly loosened so as to drop the holder 29 straight down while maintaining the posture of the holder 29 without shifting to the fully open state. The chuck device forms a small gap with the holder 29. The chuck device is opened to an opening degree that prevents the holder 29 from tilting obliquely from an inverted vertical posture. Such an opening of the chuck device is also called an intermediate opening. In this step, the chuck device provides a guide member that drops in the axial direction while suppressing the holder 29 from falling down.

  Step 154 is a free fall process. Here, the holder 29 naturally falls on the heater 32 only by its own weight. By dropping the holder 29 with its own weight from above the heater 32 held in the vertical posture, a dropping step is provided in which the holder 29 is brought into contact with the tip of the heater 32 by its own weight.

  Since the holder 29 is covered with the heater 32 with the large-diameter contact portion 37 facing down, and has a cone portion between the contact portion 37 and the heater holding portion 35, the holder 29 has its own weight. Thus, the center axis AX of the holder 29 is made to coincide with the center axis AX of the heater 32. That is, alignment is automatically realized only by the weight of the holder 29. Thereby, damage to the heater 32 and excessive deformation of the holder 29 are suppressed. For example, a corner or surface chip of the heater 32 is suppressed.

  Step 155 is a combination process of placing the holder 29 on the tip of the heater 32. Here, the holder 29 dropped in step 154 is put on the heater 32 installed in steps 145-151. The holder 29 falls on the heater 32 with its own weight alone and comes into contact with the holder 29 to be put on the tip.

  FIG. 22 shows the movement of the holder 29 from step 152 to step 154. In the figure, a control device 70 for controlling a gas sensor manufacturing apparatus is shown. The control device 70 controls the manufacturing apparatus in a plurality of steps illustrated in FIG. The control device 70 controls the plurality of holding devices in the dropping process and the combining process. These holding devices include a chuck device that can be opened and closed so as to be in contact with or separated from the holder 29 or the heater 32, and a stationary base or guide member. The holding device has a shape in contact with the holder 29 or the heater 32 so as to restrict the movement of the holder 29 or the heater 32. For example, at least a portion of the holding device can be provided by a U-shaped cavity that can receive the holder 29 or heater 32 radially or axially, or a member that forms a round hole.

  The control device is an electronic control unit. The control device has at least one arithmetic processing unit (CPU) and at least one memory device as a storage medium for storing programs and data. The control device is provided by a microcomputer including a computer-readable storage medium. The storage medium stores a computer-readable program non-temporarily. The storage medium can be provided by a semiconductor memory or a magnetic disk. The controller can be provided by a computer or a set of computer resources linked by a data communication device. The program is executed by the control device to cause the control device to function as the device described in this specification and to cause the control device to perform the method described in this specification. The control device provides various elements. At least some of those elements can be referred to as means for performing the function, and in another aspect, at least some of those elements are blocks that are interpreted as a configuration, or modules that are interpreted as a configuration. Can be called.

  The means and / or functions provided by the control device can be provided by software recorded in a substantial memory device and a computer that executes the software, software only, hardware only, or a combination thereof. For example, if the controller is provided by an electronic circuit that is hardware, it can be provided by a digital circuit including a number of logic circuits, or an analog circuit.

  Stage (a) is the initial stage of step 152. The heater 32 is held by a holding device. The heater 32 is held by a chuck device 71 and a chuck device 72 that can be opened and closed, a pedestal 73, and a lead support 74. The pedestal 73 and the lead support 74 can be provided by a stationary member or a movable member. The holder 29 is held and conveyed by a holding device. The holding device includes a chuck device 76 that can be opened and closed by a drive mechanism 75. The holder 29 is conveyed onto the heater 32.

  Stage (b) is the latter stage of step 152. The holder 29 is positioned such that the tip of the heater 32 is positioned in the contact portion 37. In other words, the holder 29 is positioned such that the tip of the heater 32 is located in a large diameter portion having a diameter larger than the circumferential slit 39 of the holder 29. Thereby, suppression of the collision with the slit edge 39a and the corner | angular part 32a is achieved, suppressing the fall distance in a subsequent dropping process. The holder 29 is positioned so as to avoid a collision with the slit edge 39a in the radial direction. The holder 29 may reach the conical surface portion 35 a between the contact portion 37 and the heater holding portion 35. However, in this step, in order to avoid a collision between the slit edge 39a and the heater 32, the heater 32 is not inserted beyond the slit edge 39a.

  Step (c) is immediately after the chuck device 76 is opened in step 153. The holder 29 is released from the chuck device 76 and falls free only by its own weight. Since the holder 29 is placed on the tip of the heater 32, the holder 29 falls onto the tip of the heater 32. Moreover, the holder 29 is brought close to the vicinity of the heater 32 in the carrying-in process. For this reason, the drop distance of the holder 29 is a slight distance. The holder 29 falls freely while being guided by the chuck device 76. The chuck device 76 provides a guide member. At this time, the chuck device 76 continues to guide the holder 29 so as to avoid a collision between the slit edge 39a and the corner 32a of the heater 32.

  Stage (d) is the final stage of step 154. The diameter of the heater 32 is smaller than the inner diameter of the holder 29 at the position of the slit edge 39a. For this reason, the tip of the heater 32 is inserted into the holder 29 beyond the slit edge 39a. The diameter of the heater 32 is larger than the inner diameter of the heater holding portion 35. For this reason, although the front-end | tip part of the heater 32 reaches | attains the cone surface part 35a, the corner | angular part 32a contacts the inner surface of the cone surface part 35a. Thereby, the insertion amount by freely dropping the holder 29 is defined. After the dropping process, the holder 29 is stably positioned on the tip of the heater 32 during the combination process. Step (d) shows the press-fitting start position of the holder 29 and the heater 32. The heater 32 is press-fitted into the heater holding portion 35 from the illustrated position.

  FIG. 23 shows the movement of the holder 29 in step 153. Stage (a) is an initial stage. As the holder 29 falls, the tip of the heater 32 gradually enters the back of the holder 29. Stage (b) is an intermediate stage. At this time, the tip of the heater 32 passes through the slit edge 39a. At this time, the corner portion 32a passes through the radially inner side of the slit edge 39a without colliding with the slit edge 39a. The heater 32 of this embodiment has a stepped shape at the tip, and a corner portion 32a is formed by the stepped portion. Such a shape is formed by providing a heating element around the ceramic core. By avoiding the collision between the slit edge 39a and the corner portion 32a, breakage at the corner portion 32a is suppressed. Stage (c) is a late stage. The corner portion 32a contacts the inner surface of the conical surface portion 35a.

  24 and 25 show a cross section of the chuck device 76 in a cross section orthogonal to the central axis AX of the holder 29. The chuck device 76 has a recess 76 a that houses at least a part of the holder 29. The recess 76 a can surround the holder 29 even when the chuck device 76 is not in contact with the holder 29. The space formed by the recess 76a accommodates the holder 29 and can prevent the holder 29 from coming out from between the chuck devices 76 in the radial direction. In other words, the recess 76a makes it possible to prevent the holder 29 from falling from the vertical posture toward the horizontal posture. FIG. 24 shows a state where the holder 29 and the chuck device 76 are in contact with each other. FIG. 25 shows the gap chuck state (intermediate chuck state) of the chuck device 76. The gap chuck state allows the holder 29 to move in the vertical direction while preventing the holder 29 from falling down.

  As shown in FIGS. 24 and 25, the dropping step is provided by slightly opening the chuck device 76 that conveys the holder 29 by contacting the outer peripheral surface of the holder 29. In the dropping process, the holder 29 is dropped in the axial direction while suppressing the falling of the holder 29 by the chuck device 76. The chuck device 76 preferably has a recess 76a in order to prevent the holder 29 from falling in all directions.

  FIG. 26 shows an example in which the slit edge 39a collides with the corner portion 32a. When the holder 29 is translated or inclined in the dropping process, the slit edge 39a may collide with the corner portion 32a. In the drawing, the case where the center axis AX29 of the holder 29 is tilted by the collision angle RD1 with respect to the center axis AX32 of the heater 32 is illustrated. The parallel movement amount and / or inclination angle of the holder 29 is regulated by the contact between the heater 32 and the holder 29. Therefore, the condition that the slit edge 39a and the corner portion 32a collide can be mathematically shown based on the diameter and length of the heater 32 and the holder 29. In this embodiment, the chuck device 76 regulates the amount of translation and / or the tilt angle between the central axis AX29 and the central axis AX32 so that the slit edge 39a and the corner 32a do not collide.

  FIG. 27 shows an example in which the collision between the slit edge 39a and the corner 32a is avoided by the chuck device 76 suppressing the holder 29 from falling. As shown in the drawing, the chuck device 76 does not come into contact as strongly as the holder 29 is held, but is positioned so as to regulate the inclination angle of the holder 29. The chuck device 76 restricts the inclination angle of the holder 29 to a suppression angle RD2 that is less than the collision angle RD1. Thereby, when the heater 32 reaches the position of the slit edge 39a, a gap GP is formed between the slit edge 39a and the corner portion 32a.

  Returning to FIG. 21, step 156 is a press-fitting process for press-fitting the heater 32 into the holder 29. Here, the heater 32 is press-fitted into the holder 29 so that the heater unit 31 is assembled. In the press-fitting step, the holder 29 is pushed down from top to bottom while the heater 32 is fixed in an inverted vertical position. In the press-fitting process, a press-fitting tool that contacts the flange portion 29b, for example, an annular punch tool is used. The holder 29 is pushed down to a specified position.

  The combination process 155 and the press-fitting process 156 are performed with the heater 32 and the holder 29 positioned in a vertical posture. In the alignment step 142, the holder 29 is aligned in a vertical posture by bringing the circumferential slit 39 into contact with the guide rail 63. Therefore, in the aligning step 142, the holder 29 can be aligned in a vertical posture suitable for the subsequent combining step 155 and the press-fitting step 156.

  Step 157 is a discharge process in which the heater unit 31 manufactured by the manufacturing method of Steps 141-156 is taken out from the work table. Here, the heater unit 31 is taken out of the work table by the transfer device and transferred to the next step. Various devices such as an articulated robot and a SCARA robot can be used as the transfer device.

  Step 148 is an assembly process of the gas sensor 10. In this assembly process, the heater unit 31 is press-fitted into the sensor element 13 and fixed. In this step, the holder 29, the heater 32, and the sensor element 13 are positioned in a predetermined positional relationship.

  In this embodiment, a gas sensor manufacturing method and a manufacturing apparatus are provided. The holding devices 71, 72, 73, 74, 76 hold the heater 32 and the holder 29 in a vertical posture in which the tip of the heater 32 can be inserted into the holder 29. The holding devices 71, 72, 73, and 74 provide a lower holding device. The holding devices 71, 72, 73, 74 position the heater 32 below the holder 29. The chuck device 76 provides an upper holding device. The chuck device 76 positions the holder 29 on the heater 32. The chuck device 76 can be opened so that the holder 29 positioned on the upper side is dropped by its own weight. Moreover, the chuck device 76 is dropped slightly in the axial direction while suppressing the falling of the holder 29 by being slightly opened. After positioning the tip of the heater 32 inside the holder 29, the control device 70 opens the upper chuck device 76 so that the holder 29 is dropped by its own weight.

  According to this embodiment, the holder 29 and the heater 32 are positioned at the press-fitting start position by dropping the holder 29. In other words, the holder 29 and the heater 32 are brought into contact with each other when the holder 29 falls from above the heater 32 only by its own weight. For this reason, it is avoided that an excessive stress acts on the corner portion 32a at the time of the first contact, and damage to the heater 32 is avoided. Compared with the case where the upper chuck device 76 firmly holds the holder 29 and the heater 32 is inserted into the holder 29 to the press-fitting start position, the force when the corner portion 32a contacts the holder 29 is suppressed, and the heater The damage of 32 is suppressed.

  In addition, the chuck device 76 suppresses the tilt of the holder 29 in the dropping process. Thereby, the collision with the slit edge 39a and the corner | angular part 32a is suppressed. As a result, since the chipping of the corner portion 32a is suppressed, low-cost production is possible. In addition, stable quality can be provided.

  According to this embodiment, the vertical holder 29 and the vertical heater 32 are combined. Other processes suitable for the process in such a vertical posture are combined. One of them is an alignment process for aligning the holder 29 in a vertical posture. Thereby, the holder 29 is easily supplied to the subsequent mounting process and press-fitting process. According to this embodiment, a series of steps for connecting the holder 29 and the heater 32 can be performed efficiently.

(Twelfth embodiment)
This embodiment is a modification based on the preceding embodiment. Instead of the above embodiment, the holder 29 and the heater 32 may be combined by dropping the heater 32 into the holder 29 from the top to the bottom.

  FIG. 28 is a transition diagram corresponding to FIG. In this embodiment, the holder 29 is held in a vertical posture in which the contact portion 37 is positioned up and the heater holding portion 35 is positioned down. The holder 29 is held by a holding device 77. The heater 32 is held in a vertical posture with its leading end positioned downward and the lead 34 positioned upward. The heater 32 is held and conveyed by a chuck device 79 that can be opened and closed by a drive mechanism 78.

  Stage (a) is provided in step 152. The heater 32 is positioned on the holder 29. Step (b) is provided in step 153. The tip of the heater 32 is inserted into the holder 29. This provides a state that is upside down from step (b) of FIG. Step (c) is provided in step 154. When the chuck device 79 is opened, the heater 32 freely falls into the holder 29. At this time, the chuck device 79 suppresses the falling of the heater 32. Paragraph (d) is provided in step 155. When the heater 32 freely falls, the tip of the heater 32 reaches the conical surface portion 35 a without colliding with the edge of the circumferential slit 39 of the holder 29. As a result, by dropping the heater 32, a combination process is provided in which the holder 29 is put on the tip of the heater 32.

  In this embodiment, a gas sensor manufacturing method and a manufacturing apparatus are provided. The holding devices 77 and 79 hold the heater 32 and the holder 29 in a vertical posture in which the tip of the heater 32 can be inserted into the holder 29. The holding device 77 provides a lower holding device. The holding device 77 positions the holder 29 below the heater 32. The chuck device 79 provides an upper holding device. The chuck device 79 positions the heater 32 on the holder 29. The chuck device 79 can be opened so that the heater 32 positioned on the upper side is dropped by its own weight. Moreover, the chuck device 79 is slightly opened to drop in the axial direction while preventing the heater 32 from falling. In this embodiment as well, damage to the heater 32 is suppressed.

(Other embodiments)
The invention disclosed herein is not limited to the embodiments for carrying out the invention, and can be implemented with various modifications. The disclosed invention is not limited to the combinations shown in the embodiments, and can be implemented in various combinations. Embodiments can have additional parts. The portion of the embodiment may be omitted. The parts of the embodiments can be replaced or combined with the parts of the other embodiments. The structure, operation, and effect of the embodiment are merely examples. The technical scope of the disclosed invention is not limited to the description of the embodiments. Some technical scope of the disclosed invention is indicated by the description of the claims, and should be understood to include all modifications within the meaning and scope equivalent to the description of the claims. It is.

  For example, the holder 29 can have various shapes without being limited to the illustrated shape. For example, an additional slit can be provided to obtain good electrical contact at the contact portion 37. Further, the terminal portion 29a can have various shapes. For example, the terminal portion 29a may have a shorter shape than the illustrated form. Further, the contact portion 37 provided in the holders 29 and 329 may adopt a configuration in which the contact portion 37 is not in electrical contact with the electrode on the inner surface of the sensor element 13. In this case, the contact portion 37 functions only as a portion for fixing the holders 29 and 329 inside the sensor element 13. In this case, a configuration is adopted in which an electric wire corresponding to the terminal portion 29a is not connected to the holders 29 and 329.

  In the above embodiment, the circumferential slit 39 or the flange portion 829b is used. However, in the alignment step, the holder 29 is aligned at a predetermined position and in a predetermined posture using both the circumferential slit 39 and the flange portion 829b. You may let them. Further, rotation around the axis of the holder 29 may be restricted by contact at one or a plurality of parts. For example, by bringing the guide rail 63 into contact with the circumferential slit 39 and / or by bringing the guide members 65, 365, 466 into contact with the first vertical slit 36, 236 or the second vertical slit 38, the holder 29 Can be controlled.

  Moreover, in the said embodiment, the holder 29 is aligned so that the contact part 37 may be located up and the heater holding | maintenance part 35 may be located down as FIG. 7 shows. Instead of this, the holder 29 may be aligned so that the heater holding portion 35 is positioned upward and the contact portion 37 is positioned downward.

  In the said embodiment, a guide member is provided by the chuck apparatus which is a holding | maintenance apparatus. Alternatively, the guide member may be provided by a member provided separately from the chuck device. For example, the holder 29 released from the chuck device 76 may be guided by a static member arranged in the vicinity of the chuck device 76. In this case, the chuck device 76 can be opened without stopping at the intermediate chuck opening. Similarly, a guide member for guiding the heater 32 may be provided in the vicinity of the chuck device 79. These guide members can be provided by a U-shaped cavity that can receive the holder 29 or the heater 32 in the radial direction or the axial direction, or a member that forms a round hole.

10 gas sensor, 13 sensor element, 28 first sensor terminal,
29 Second sensor terminal, holder,
29a terminal part, 29b, 829b flange part,
31 heater unit, 32 heater, 32a corner, 34 lead,
35 heater holding part, 35a conical surface part, 36, 236 slit,
37 contact parts, 38 slits,
39 circumferential slits, 39a slit edges,
61 parts feeder, 62 transport path,
63, 867, 868, 62a, 962a guide rails,
71, 72, 73, 74, 76, 77, 79 holding device,
75, 78 Drive mechanism.

Claims (20)

A cup-shaped sensor element (13);
A rod-like heater (32) having a base end portion provided with a lead (34) for energization and a tip end portion disposed inside the sensor element;
A heater contact portion (35) that is disposed inside the sensor element, contacts the outer peripheral surface of the heater and holds the heater, and a sensor contact portion that contacts the inner surface of the sensor element and is fixed in the sensor element ( 37) and a holder (29) for supporting the heater inside the sensor element,
Guide rails (63, 867, 868) extending along circumferential direction slits or flanges (39, 829b) extending along a plane (HP) orthogonal to the central axis (AX) of the holder, along the conveying direction of the holder Aligning the holder by contacting the holder and maintaining the posture of the holder (142);
A gas sensor manufacturing method comprising: a gas sensor assembly step (148) for disposing the holder in the sensor element.   The gas sensor manufacturing method according to claim 1, wherein the aligning step aligns the holder in a vertical posture by bringing the circumferential slit or the flange portion into contact with the guide rail. The heater contact portion is formed in a C-shaped cross section by a first vertical slit (36) extending along the axial direction,
The sensor contact portion is formed in a C-shaped cross section by a second vertical slit (38) extending along the axial direction.
The circumferential slit (39) is provided over an angular range that does not reach 360 degrees along the circumferential direction so as to leave a connecting portion that connects the heater contact portion (35) and the sensor contact portion (37). And
In the alignment step, the guide rail is brought into contact with the circumferential slit and / or the guide member (65, 365, 466) is brought into contact with the first vertical slit or the second vertical slit. The method for manufacturing a gas sensor according to claim 1, wherein rotation around the axis of the holder is restricted. The guide rail (63) is a plate-like member that can be inserted into the circumferential slit,
The gas sensor manufacturing method according to any one of claims 1 to 3, wherein, in the alignment step, the guide rail is inserted into the circumferential slit. The flange portion is formed so as to extend radially outward from an end portion of the holder,
The guide rails (867, 868) are members that form a gap into which the flange portion can be inserted,
The method for manufacturing a gas sensor according to any one of claims 1 to 3, wherein in the alignment step, the flange portion is inserted into the gap. The holder (29) has a terminal portion (29a) extending axially to provide an electrical connection;
The guide rails (867, 868) are
A pair of first guide rails (867) disposed on both sides of the sensor contact portion of the holder;
A pair of second guide rails (868) disposed on both sides of the terminal portion and preventing rotation around the axis of the holder by interfering with the terminal portion;
6. The method of manufacturing a gas sensor according to claim 5, wherein, in the alignment step, the holder is positioned between the pair of first guide rails and between the pair of second guide rails. The heater contact portion is formed in a C-shaped cross section by a first vertical slit (36) extending along the axial direction,
The sensor contact portion is formed in a C-shaped cross section by a second vertical slit (38) extending along the axial direction.
The gas sensor according to any one of claims 1 to 6, wherein the first vertical slit and the second vertical slit are provided apart from each other around the axis of the holder. Production method. Further, a dropping step (154) of covering the tip of the heater with the holder by dropping one of the heater and the holder;
The method for manufacturing a gas sensor according to any one of claims 1 to 7, further comprising a press-fitting step (156) for assembling a heater unit by press-fitting the heater into the holder.   The method of manufacturing a gas sensor according to claim 8, wherein the dropping step is performed with the heater and the holder positioned in a vertical posture. A cup-shaped sensor element (13);
A rod-like heater (32) having a base end portion provided with a lead (34) for energization and a tip end portion disposed inside the sensor element;
A heater holding portion (35) disposed inside the sensor element and contacting the outer peripheral surface of the heater to hold the heater, and a contact portion (37) contacting the electrode provided on the inner surface of the sensor element. And a gas sensor manufacturing method comprising a holder (29) for supporting the heater inside the sensor element,
Holding the heater and the holder in a vertical position (151, 152);
Positioning one of the heater and the holder on the other and dropping one of the heater and the holder under its own weight to insert the tip of the heater into the holder (154);
A press-fitting step (156) for assembling a heater unit by press-fitting the heater into the holder;
A gas sensor manufacturing method comprising: a gas sensor assembly step (148) for disposing the heater unit in the sensor element.   The dropping step is performed in the axial direction while suppressing the fall of one of the heater and the holder away from the holding device (76, 79) that conveys by holding one of the heater and the holder by a guide member. The method of manufacturing a gas sensor according to any one of claims 8 to 10, wherein the gas sensor is dropped.   One of the heater and the holder falls while being guided by the guide member so as to avoid a collision between a slit edge (39a) of a circumferential slit provided in the holder and the heater. Item 12. A method for manufacturing a gas sensor according to Item 11.   Further, before the dropping step, the holder is separated from the heater, but the holding device positions one of the heater and the holder to a position where the contact portion of the holder covers the tip portion ( 152). The method of manufacturing a gas sensor according to claim 11 or claim 12, further comprising: Before the dropping step, a holding step (151) for holding the heater in a vertical posture with the base end portion facing down and the tip end portion facing up,
In the dropping step, the holder is caused to fall by its own weight from above the heater held in a vertical posture, so that the holder is brought into contact with the tip of the heater by its own weight, and the holder covers the heater. The method of manufacturing a gas sensor according to claim 8, wherein the gas sensor is held by the gas sensor. A cup-shaped sensor element (13);
A rod-like heater (32) having a base end portion provided with a lead (34) for energization and a tip end portion disposed inside the sensor element;
A heater contact portion (35) that is disposed inside the sensor element, contacts the outer peripheral surface of the heater and holds the heater, and a sensor contact portion that contacts the inner surface of the sensor element and is fixed in the sensor element ( 37) and a gas sensor manufacturing apparatus comprising a holder (29) for supporting the heater inside the sensor element,
A guide rail that extends along the conveyance direction of the holder, and is brought into contact with a circumferential slit or flange portion (39, 829b) that extends along a plane (HP) orthogonal to the central axis (AX) of the holder. An apparatus for manufacturing a gas sensor, comprising guide rails (63, 867, 868) for aligning the holder and maintaining the posture of the holder.   The gas sensor manufacturing apparatus according to claim 15, wherein the guide rail (63) is a plate-like member that can be inserted into the circumferential slit. The flange portion is formed so as to extend radially outward from an end portion of the holder,
The gas sensor manufacturing apparatus according to claim 15, wherein the guide rail (867, 868) is a member that forms a gap into which the flange portion can be inserted. The holder (29) has a terminal portion (29a) extending axially to provide an electrical connection;
The guide rails (867, 868) are
A pair of first guide rails (867) disposed on both sides of the sensor contact portion of the holder;
18. A pair of second guide rails (868) disposed on both sides of the terminal portion and preventing rotation around the axis of the holder by interfering with the terminal portion. Gas sensor manufacturing equipment. A cup-shaped sensor element (13);
A rod-like heater (32) having a base end portion provided with a lead (34) for energization and a tip end portion disposed inside the sensor element;
A heater holding portion (35) disposed inside the sensor element and contacting the outer peripheral surface of the heater to hold the heater, and a contact portion (37) contacting the electrode provided on the inner surface of the sensor element. And a gas sensor manufacturing apparatus comprising a holder (29) for supporting the heater inside the sensor element,
An upper holding device (76, 79) for holding the heater and the holder in a vertical posture in which the tip of the heater can be inserted into the holder, and positioning one of the heater and the holder on the other and the lower Holding device (71, 72, 73, 74, 77);
A gas sensor comprising: a control device (70) for opening the upper holding device so as to drop one of the heater and the holder by its own weight after positioning the tip of the heater inside the holder. Manufacturing equipment.   The apparatus for manufacturing a gas sensor according to claim 19, wherein the control device causes the guide member to drop one of the heater and the holder that are separated from the upper holding device while being axially suppressed.

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