Method of manufacturing a measuring device

Abstract

To simplify manufacturing of a measuring device.SOLUTION: A manufacturing method for measuring device includes: a step which prepares a structure provided with a cylindrical housing where a first end and a second end are opened in one direction, a thermo couple extending in one direction in the housing, and a columnar piece provided in the housing, exposed from the first end and holding the thermo couple; a step which fixes the piece to the housing by first welding on an end surface of the structure including the first end; and a step which polishes a welding part and an apical surface formed by first welding. The piece has a side surface facing an inner surface of the housing. A pair of grooves which respectively go through the piece in one direction are provided on the side surface. In the step preparing the structure, the thermo couple is housed between the pair of grooves and the inner surface of the housing by inserting the piece in the housing.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a method for manufacturing a measuring device. In the law

Background Art

[0002] A method for manufacturing a measuring device for measuring the temperature of a mold wall for injection molding is known (see, for example, Patent Document 1). In this manufacturing method, a measuring element is inserted into a hole provided in a sensor body for each measuring element, and the front surface of the measuring element and the sensor body is polished with the measuring element protruding slightly from the front surface of the sensor body.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the manufacturing method described in Patent Document 1, since the inner diameter of the hole provided in the sensor body is approximately the same as the outer diameter of the measuring element, it may not be possible to easily insert the measuring element into the hole. In this technical field, it is required to easily manufacture the measuring device.

Means for Solving the Problems

[0005] A method for manufacturing a measuring device according to one aspect of the present disclosure includes the steps of: preparing a structure comprising a cylindrical housing having a first and second end open in one direction; a thermocouple extending in one direction within the housing; and a columnar piece provided within the housing, exposed from the first end, and holding the thermocouple; fixing the piece to the housing by first welding at the tip surface of the structure including the first end; and polishing the welded portion and tip surface formed by the first welding. The piece has a side facing the inner surface of the housing. The side is provided with a pair of grooves, each penetrating the piece in one direction. In the step of preparing the structure, the thermocouple is housed between the pair of grooves and the inner surface of the housing by inserting the piece into the housing.

[0006] In this method of manufacturing the measuring device, a piece is inserted into the housing, and a thermocouple is housed between a pair of grooves provided on the side of the piece and the inner surface of the housing. That is, a hole is formed by the inner surface of the housing and each groove, but the thermocouple is already housed in the hole at the time the hole is formed. Therefore, the work of passing the thermocouple through the hole is unnecessary. As a result, the manufacturing of the measuring device can be simplified.

[0007] In the process of preparing the structure, after the thermocouple is inserted into the housing, a piece may be inserted into the housing so that the thermocouple is housed between a pair of grooves and the inner surface of the housing. In this case, after aligning the thermocouple with the pair of grooves in the width direction of the grooves, the piece is inserted into the housing, and as the piece is inserted, the thermocouple is fitted into the grooves along the grooves. Then, a hole is formed by the inner surface of the housing and each groove, and the thermocouple is housed in the hole at the time the hole is formed. For example, in order to insert a thermocouple into a hole with an inner diameter about the same as the outer diameter of the thermocouple, it is necessary to align the thermocouple with the hole in two axes. In contrast, in the above manufacturing method, the alignment in two axes (the width direction of the groove and the length direction of the groove) is performed individually. Therefore, compared to inserting a thermocouple into a hole provided in the housing, the manufacturing of the measuring device can be simplified.

[0008] In the process of preparing the structure, with the thermocouples housed in a pair of grooves, the thermocouples may be fixed to the front surface of the component by auxiliary welding, and then the component and thermocouples may be inserted into the housing so that the front surface is exposed from the first end, thereby housing the thermocouples between the pair of grooves and the inner surface of the housing. In this case, the thermocouples and the pair of grooves can be aligned in the width direction of the grooves, and then the component and thermocouples can be aligned along the grooves. Therefore, since the alignment in two axes (the width direction of the grooves and the length direction of the grooves) can be performed individually, the manufacturing of the measuring device can be simplified compared to the case where the thermocouples are inserted into holes provided in the housing.

[0009] The first welding may be performed inside the outer edge of the first end. This prevents deformation such as sagging of the outer edge caused by welding. As a result, the flatness of the polished tip surface can be improved.

[0010] The first welding may be performed along the boundary between the housing and the component at the tip surface. In this case, since the boundary between the housing and the component at the tip surface is welded without any gaps, the joint strength between the housing and the component is improved. As a result, the pressure resistance performance of the measuring device is improved.

[0011] The above-described method for manufacturing the measuring device may further include a step of fixing the piece to the housing by a second welding on the outer surface of the housing. In this case, since the piece is fixed to the housing not only on the tip surface but also on the outer surface, the joint strength between the housing and the piece is further improved. As a result, the pressure resistance performance of the measuring device is further improved.

[0012] A groove may be provided on the outer surface of the housing. The second welding may be performed in the groove. In this case, even if deformation such as bulging occurs in the housing due to the second welding, such deformation will occur within the groove. Therefore, the possibility of the deformed portion protruding from the outer surface can be reduced. For example, when a measuring device is used by being inserted into a hole provided in a mold, the possibility of problems such as being unable to insert it into the hole can be reduced.

[0013] In the process of polishing the weld and tip surface, the weld and tip surface may be polished so that the tip of the thermocouple is exposed. This process shortens the time it takes for heat to reach the pair of wires when the measuring device is used. This makes it possible to improve the responsiveness of the measuring device.

[0014] A measuring device according to another aspect of the present disclosure comprises a cylindrical housing having a first end and a second end in one direction, with the first and second ends open; a thermocouple extending in one direction within the housing; and a columnar piece provided within the housing, exposed from the first end, and holding the thermocouple. The piece has a side facing the inner surface of the housing and a front surface exposed from the first end. The side surface is provided with a pair of grooves that penetrate the piece in one direction. The thermocouple is housed in the pair of grooves and extends to the front surface.

[0015] In this measuring device, a thermocouple is housed between a pair of grooves on the side of a component and the inner surface of the housing. Because the component and the housing are separate parts, inserting the component into the housing allows the thermocouple to be housed in the pair of grooves. In other words, holes are formed by the inner surface of the housing and each groove, but the thermocouple is housed in these holes at the time the holes are formed. Therefore, the process of threading the thermocouple through the holes is unnecessary. As a result, the manufacturing of the measuring device can be simplified. [Effects of the Invention]

[0016] According to this disclosure, the manufacturing of measuring devices can be facilitated. [Brief explanation of the drawing]

[0017] [Figure 1] Figure 1 is a cross-sectional view showing the configuration of the measuring device. [Figure 2] Figure 2 is a cross-sectional view showing an enlarged view of area P in Figure 1. [Figure 3] Figure 3 is a process diagram showing an example of a method for manufacturing a measuring device according to the first embodiment. [Figure 4](a) of FIG. 4 is a plan view for explaining the insertion step S11 of FIG. 3. (b) of FIG. 4 is a cross-sectional view showing a cross-section along the line A1-A1 of (a) of FIG. 4. [Figure 5] (a) of FIG. 5 is a plan view for explaining the insertion step S12 of FIG. 3. (b) of FIG. 5 is a cross-sectional view showing a cross-section along the line A2-A2 of (a) of FIG. 5. [Figure 6] (a) of FIG. 6 is a plan view for explaining the fixing step S2 of FIG. 3. (b) of FIG. 6 is a cross-sectional view showing a cross-section along the line A3-A3 of (a) of FIG. 6. [Figure 7] (a) of FIG. 7 is a plan view for explaining the fixing step S3 of FIG. 3. (b) of FIG. 7 is a cross-sectional view showing a cross-section along the line A4-A4 of (a) of FIG. 7. [Figure 8] (a) of FIG. 8 is a plan view for explaining the polishing step S4 of FIG. 3. (b) of FIG. 8 is a cross-sectional view showing a cross-section along the line A5-A5 of (a) of FIG. 8. [Figure 9] FIG. 9 is a process diagram showing an example of a method for manufacturing a measuring device according to the second embodiment. [Figure 10] (a) of FIG. 10 is a plan view for explaining the insertion step S51 of FIG. 9. (b) of FIG. 10 is a cross-sectional view showing a cross-section along the line B1-B1 of (a) of FIG. 10. [Figure 11] (a) of FIG. 11 is a plan view for explaining the fixing step S52 of FIG. 9. (b) of FIG. 11 is a cross-sectional view showing a cross-section along the line B2-B2 of (a) of FIG. 11. [Figure 12] (a) of FIG. 12 is a plan view for explaining the insertion step S53 of FIG. 9. (b) of FIG. 12 is a cross-sectional view showing a cross-section along the line B3-B3 of (a) of FIG. 12.

Embodiments for Carrying Out the Invention

[0018] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In each figure, the same parts or corresponding parts are denoted by the same reference numerals, and redundant descriptions are omitted.

[0019] [Measuring device] Referring to Figures 1 and 2, a measuring device manufactured by the manufacturing method of the measuring device according to the embodiment will be described. Figure 1 is a cross-sectional view showing the configuration of the measuring device. Figure 2 is a cross-sectional view showing an enlarged view of area P in Figure 1. The measuring device 1 shown in Figure 1 is a temperature sensor that measures the temperature of the surface of a mold for injection molding. The measuring device 1 has a rod-like shape extending in the Z direction (one direction). The measuring device 1 is inserted into a hole provided in the mold along the central axis CL. The tip surface 1a of the measuring device 1 in the Z direction is in contact with the resin that has flowed into the mold to be measured. At this time, the tip surface 1a forms part of the mold.

[0020] The measuring device 1 comprises a tube 2, a crimping ring 3, a housing 4, a thermocouple 5, and a piece 6. The tube 2 is a tubular member made of, for example, fluororesin. The tube 2 covers the thermocouple 5. The tip of the thermocouple 5 is not covered by the tube 2 and protrudes from the tip of the tube 2. The crimping ring 3 is a cylindrical member having a notch extending from one end to the other. In other words, the cross-section of the crimping ring 3 perpendicular to the central axis CL has a C-shape. At the tip of the tube 2, the crimping ring 3 restrains the thermocouple 5 from the outer circumferential surface of the tube 2.

[0021] The housing 4 is a cylindrical member with a first end 4a and a second end 4b open in the Z direction. In one example, the housing 4 has a cylindrical shape. The housing 4 is made of stainless steel (e.g., SUS630). The housing 4 is provided with a hole H that penetrates the housing 4 from the first end 4a to the second end 4b. The housing 4 comprises a base end 41, a flange 42, a cylindrical part 43, a cylindrical part 44, and a tip end 45. The base end 41, flange 42, cylindrical part 43, cylindrical part 44, and tip end 45 are arranged in this order from the second end 4b to the first end 4a.

[0022] The base portion 41 includes the second end 4b. The tip of the tube 2 is press-fitted into the base portion 41 from the second end 4b together with the crimping ring 3. The flange portion 42 protrudes outward around the entire circumference of the housing 4 around the central axis CL. The flange portion 42 is for positioning the tip surface 1a. For example, when the measuring device 1 is inserted into a hole provided in the mold, the flange portion 42 abuts against a part of the mold. This determines the position of the tip surface 1a. The cylindrical portion 43, cylindrical portion 44, and tip portion 45 house the tip of the thermocouple 5 that is not covered by the tube 2. The inner diameter of the cylindrical portion 43 is larger than the inner diameters of the cylindrical portion 44 and tip portion 45.

[0023] As shown in Figure 2, the tip portion 45 is the portion that includes the first end 4a. The outer edge 46 of the first end 4a is furthest from the central axis CL at the first end 4a. The housing 4 has an outer circumferential surface 4c and an inner surface 4d. A groove 47 is provided on the outer circumferential surface 4c of the tip portion 45. The groove 47 is, for example, a portion of the outer circumferential surface 4c that is concavely recessed toward the central axis CL. The groove 47 is provided, for example, around the entire circumference of the outer circumferential surface 4c with respect to the central axis CL. The groove 47 is provided, for example, in a position that surrounds the outer circumference of the back surface 6b, which will be described later.

[0024] The thermocouple 5 extends in the Z direction within the housing 4. The thermocouple 5 measures the temperature difference based on the thermoelectric power at the junction between two different types of metal wires (a pair of strands 53) and the object to be measured. Each strand 53 is individually covered by a coating 52, and the pair of strands 53 covered by the coating 52 are further covered together by a coating 51. The tips of the pair of strands 53 are not covered (exposed). The portion of the thermocouple 5 covered by the coating 51 is housed in the cylindrical portion 43. The portion of the thermocouple 5 covered by the coating 52 is housed in the cylindrical portion 44. Hereinafter, the direction in which the pair of strands 53 are aligned will be referred to as the X direction. The direction perpendicular to the X and Z directions will be referred to as the Y direction.

[0025] The component 6 is a columnar member that holds the thermocouple 5. In one example, the component 6 has a cylindrical shape. The component 6 is made of stainless steel (e.g., SUS630). The component 6 is provided inside the housing 4 and is exposed from the first end 4a. Specifically, the component 6 is housed in the tip portion 45 of the housing 4. The outer diameter of the component 6 is approximately the same as the inner diameter of the housing 4 (tip portion 45). The component 6 has a front surface 6a and a back surface 6b, which are both end surfaces in the Z direction, and a side surface 6c. The front surface 6a is exposed from the first end 4a. The side surface 6c faces the inner surface 4d of the housing 4 (tip portion 45).

[0026] A pair of grooves 61 are provided on the side surface 6c, penetrating the piece 6 in the Z direction. Each groove 61 extends from the front surface 6a to the back surface 6b. In this embodiment, the pair of grooves 61 are provided symmetrically with respect to the central axis CL. Each groove 61 is recessed toward the central axis CL. The cross section of each groove 61 perpendicular to the central axis CL has, for example, a U-shape. The groove width and groove depth of each groove 61 are greater than the diameter of the wire 53. Each groove 61 houses the wire 53 of the thermocouple 5 (the portion not covered by the coating 52) along its entire length, and the tip 53c of the wire 53 is exposed at the tip surface 1a.

[0027] The measuring device 1 further comprises a welded section 7 and a welded section 8. The welded section 7 is provided on the tip surface 1a. In this embodiment, the welded section 7 is provided in a circular shape along the boundary line between the housing 4 and the piece 6 on the tip surface 1a. The housing 4 (tip section 45), the piece 6, and the thermocouple 5 are fixed together on the tip surface 1a by the welded section 7. The welded section 8 is provided in the groove section 47. The welded section 8 is provided around the entire circumference of the groove section 47. The housing 4 and the piece 6 (bottom section) are fixed together by the welded section 8.

[0028] [First Embodiment] Next, with reference to Figure 3, a method for manufacturing the measuring device 1 according to the first embodiment will be described. Figure 3 is a process diagram showing an example of a method for manufacturing the measuring device 1 according to the first embodiment. As shown in Figure 3, manufacturing method M1 is a method for manufacturing the measuring device 1 and includes a preparation step S1, a fixing step S2, a fixing step S3, and a polishing step S4.

[0029] <Preparation process S1> First, preparation step S1 is performed. Preparation step S1 is the process of preparing the structure 10. The structure 10 comprises a housing 14, a thermocouple 15, and a piece 16 (see Figure 5(b)). The housing 14 is the basic component of the housing 4 of the measuring device 1, and differs from the housing 4 mainly in that it includes a tip 145 instead of a tip 45. The tip 145 is the basic component of the tip 45, and differs from the tip 45 mainly in that it includes a first end 14a, an outer surface 14c, and an inner surface 14d instead of a first end 4a, an outer surface 4c, and an inner surface 4d. The first end 14a, the outer surface 14c, and the inner surface 14d are the basic components of the first end 4a, the outer surface 4c, and the inner surface 4d, respectively. In other words, the housing 14 is a cylindrical member with the first end 14a and the second end 4b open in the Z direction. The outer surface 4c is provided with the groove 47 described above.

[0030] Thermocouple 15 is the component that forms thermocouple 5 of measuring device 1, and differs from thermocouple 5 mainly in that it includes a pair of strands 153 instead of a pair of strands 53. The pair of strands 153 is the component that forms the pair of strands 53, and differs from the pair of strands 53 mainly in that it further includes a tip portion 153a. The tip portion 153a is the part that includes the tip of the strand 153. Thermocouple 15 extends in the Z direction within the housing 14.

[0031] The component 16 is the basis for the component 6 of the measuring device 1, and differs from the component 6 mainly in that it includes a front surface 16a instead of a front surface 6a. The front surface 16a is the basis for the front surface 6a. The component 16 is a columnar component that holds the thermocouple 15. Specifically, the component 16 holds a pair of strands 153 spaced apart from each other in the X direction. The component 16 is provided inside the housing 14 (tip portion 145) and is exposed from the first end 14a. The component 16 has a side surface 16c facing the inner surface 14d of the housing 14. A pair of grooves 161 are provided on the side surface 16c. Each of the pair of grooves 161 penetrates the component 16 in the Z direction. A strand 153 is held in each groove 161. The structure 10 has a tip surface 10a including the first end 14a.

[0032] In preparation step S1, the thermocouple 15 is housed between the pair of grooves 161 and the inner surface 14d of the housing 14 by inserting the piece 16 into the housing 14. Preparation step S1 includes insertion step S11 and insertion step S12.

[0033] <Insertion process S11> The insertion process S11 will be described in detail with reference to Figures 4(a) and 4(b). Figure 4(a) is a plan view illustrating the insertion process S11 in Figure 3. Figure 4(b) is a cross-sectional view showing a section along the line A1-A1 in Figure 4(a). As shown in Figures 4(a) and 4(b), the insertion process S11 is the process of inserting the thermocouple 15 into the housing 14. In the insertion process S11, for example, the tip of the thermocouple 15 is inserted into the housing 14 from the second end 4b. At this time, the thermocouple 15 is inserted into the housing 14 such that the respective tip 153a of the pair of strands 153 protrude from the first end 14a to the outside of the housing 14.

[0034] Then, the pair of wires 153 are bent at approximately a right angle so that their tips 153a are spaced apart from each other in the X direction. The tip 53a of each wire 153 may be spaced further apart from the central axis CL than the outer edge 146 of the first end 14a. Each wire 153 is positioned in the Z direction by the bent tip 153a contacting the first end 14a. The pair of wires 153 are arranged symmetrically with respect to a virtual line L. The virtual line L is a virtual line that intersects the central axis CL and lies along the Y direction.

[0035] <Insertion process S12> Insertion step S12 is performed following insertion step S11. Insertion step S12 will be described in detail with reference to Figures 5(a) and 5(b). Figure 5(a) is a plan view illustrating insertion step S12 in Figure 3. Figure 5(b) is a cross-sectional view showing a section along the line A2-A2 in Figure 5(a). As shown in Figures 5(a) and 5(b), insertion step S12 is the step of inserting the piece 16 into the housing 14.

[0036] In insertion step S12, for example, the tips 153a of a pair of strands 153 are aligned and housed in a pair of grooves 161 on the back surface 16b of the compositing 16. In this state, the compositing 16 is inserted into the housing 14 from the first end 14a of the housing 14. At this time, as the compositing 16 is inserted, each strand 153 is fitted into the grooves 161 along the grooves 161. The compositing 16 is inserted into the housing 14 until the front surface 16a is flush with the first end 14a. As a result, the thermocouple 15 (a pair of strands 153) is housed between the pair of grooves 161 and the inner surface 14d of the housing 14. At this time, the front surface 16a is exposed from the first end 14a.

[0037] As described above, in preparation step S1, the thermocouple 15 is inserted into the housing 14 (insertion step S11). Subsequently, the piece 16 is inserted into the housing 14, thereby housing the thermocouple 15 between the pair of grooves 161 and the inner surface 14d of the housing 14 (insertion step S12), and the structure 10 is manufactured.

[0038] <Fixed process S2> Following the preparation step S1, the fixing step S2 is performed. The fixing step S2 will be described in detail with reference to Figures 6(a) and 6(b). Figure 6(a) is a plan view illustrating the fixing step S2 in Figure 3. Figure 6(b) is a cross-sectional view showing a section along the line A3-A3 in Figure 6(a). As shown in Figures 6(a) and 6(b), the fixing step S2 is a step of fixing the piece 16 to the housing 14 by first welding at the tip surface 10a. The tip surface 10a includes the first end 14a, the tip portions 153a of the pair of wires 153, and the front surface 16a. The housing 14, the piece 16, and the thermocouple 15 (the pair of wires 153) are joined at the tip surface 10a by first welding. For example, a YAG laser is used for the first welding.

[0039] The first welding is performed on the tip surface 10a, inside the outer edge 146 of the first end 14a. Specifically, the first welding is performed along the boundary between the housing 14 and the piece 16 on the tip surface 10a. Since this boundary is circular in shape with respect to the central axis CL, the first welding is performed circumferentially. The first welding forms a welded portion 17. Specifically, the first end 14a, the pair of wires 153, and the front surface 16a on the tip surface 10a melt and become one, thereby forming the welded portion 17. At this time, the tip portion 153a melts away due to the first welding.

[0040] <Fixed process S3> Following the fixing process S2, the fixing process S3 is performed. The fixing process S3 will be described in detail with reference to Figures 7(a) and 7(b). Figure 7(a) is a plan view illustrating the fixing process S3 in Figure 3. Figure 7(b) is a cross-sectional view showing a section along the line A4-A4 in Figure 7(a). As shown in Figures 7(a) and 7(b), the fixing process S3 is a process of fixing the piece 16 to the housing 14 by second welding on the outer circumferential surface 4c of the housing 14. The second welding is performed in a groove 47 provided on the outer circumferential surface 14c of the housing 14. Therefore, the groove 47 and the bottom of the piece 16 are joined by the second welding. For example, a YAG laser is used for the second welding.

[0041] The welded portion 8 is formed by the second welding. Specifically, the groove portion 47 and the piece 16 melt and become one, thereby forming the welded portion 8. The welded portion 8 may include a pair of wires 153 that have melted in the second welding. That is, the welded portion 8 may reach the pair of wires 153.

[0042] <Polishing process S4> Following the fixing process S3, the polishing process S4 is performed. The polishing process S4 will be described in detail with reference to Figures 8(a) and 8(b). Figure 8(a) is a plan view illustrating the polishing process S4 in Figure 3. Figure 8(b) is a cross-sectional view showing a section along the line A5-A5 in Figure 8(a). As shown in Figures 8(a) and 8(b), the polishing process S4 is a process of polishing the welded portion 17 and the tip surface 10a. For polishing, sandpaper, for example, is used.

[0043] In polishing step S4, the tip surface 1a is formed by polishing the welded portion 17 and the tip surface 10a. Specifically, the tip surface 1a is formed by polishing the welded portion 17 and the tip surface 10a so that they become flat and the pair of strands 153 are exposed. In other words, the welded portion 7, the housing 14 (first end 14a), the thermocouple 15, and the piece 16 (front surface 16a) are polished, respectively, to form the welded portion 7, the housing 4 (first end 4a), the thermocouple 5, and the piece 6 (front surface 6a). The tip 53c of the thermocouple 5 is exposed on the tip surface 1a.

[0044] Based on the above, measuring device 1 is manufactured.

[0045] As described above, in manufacturing method M1 and measuring device 1, when the piece 16 is inserted into the housing 14, the thermocouple 15 is housed between a pair of grooves 161 provided on the side surface 16c of the piece 16 and the inner surface 14d of the housing 14. That is, a hole is formed by the inner surface 14d of the housing 14 and each groove 161, but the thermocouple 15 is housed in the hole at the time the hole is formed. Therefore, the work of passing the thermocouple 15 through a hole having an inner diameter about the same as the outer diameter of the thermocouple 15 is unnecessary. As a result, the manufacturing of the measuring device 1 can be simplified.

[0046] In preparation step S1, after the thermocouple 15 is inserted into the housing 14, a piece 16 is inserted into the housing 14, thereby housing the thermocouple 15 between the pair of grooves 161 and the inner surface 14d of the housing 14. According to preparation step S1, the thermocouple 15 is aligned with the pair of grooves 161 in the width direction of the grooves 161, and then the piece 16 is inserted into the housing 14. As the piece 16 is inserted, the thermocouple 15 is fitted into the grooves 161 along the grooves 161. Then, a hole is formed by the inner surface 14d of the housing 14 and each groove 161, and the thermocouple 15 is housed in the hole at the time the hole is formed. For example, in order to insert the thermocouple 15 into a hole having an inner diameter about the same as the outer diameter of the thermocouple 15, it is necessary to align the thermocouple 15 with the hole in two axes. In contrast, in the above preparation step S1, the alignment in two axes (the width direction of the grooves 161 and the length direction of the grooves 161) is performed individually. Therefore, compared to the case where the thermocouple 15 is inserted into a hole provided in the housing, the manufacturing of the measuring device 1 can be simplified.

[0047] Since the tip surface 1a forms part of the mold, the resin molded product will have a shape corresponding to the shape of the tip surface 1a. Therefore, if deformation such as sagging occurs on the tip surface 1a, the shape of the resin molded product may not be as designed. For this reason, flatness is required of the tip surface 1a. In response to this, in the fixing process S2, the first welding is performed inside the outer edge 146 of the first end 14a. This prevents deformation such as sagging of the outer edge 146 caused by welding. As a result, the flatness of the tip surface 1a formed by polishing can be improved.

[0048] In fixing process S2, the first welding is performed along the boundary between the housing 14 and the piece 16 at the tip surface 10a. As a result, the boundary between the housing 14 and the piece 16 at the tip surface 10a is welded without any gaps, improving the joint strength between the housing 14 and the piece 16. Consequently, the pressure resistance performance of the measuring device 1 is improved.

[0049] In fixing step S3, the piece 16 is fixed to the housing 14 by a second weld on the outer surface 14c of the housing 14. Therefore, since the piece 16 is fixed to the housing 14 not only on the tip surface 10a but also on the outer surface 14c, the joint strength between the housing 14 and the piece 16 is further improved. As a result, the pressure resistance performance of the measuring device 1 is further improved.

[0050] For example, when the measuring device 1 is used by being inserted into a hole provided in a mold, if the outer circumferential surface 4c of the housing 4 is raised, there is a risk that it may not be possible to insert it into the hole. In contrast, the second welding is performed in a groove 47 provided on the outer circumferential surface 14c of the housing 14. As a result, even if deformation such as bulging occurs in the housing 14 due to the second welding, the deformation occurs within the groove 47. Therefore, the possibility of the deformed portion protruding from the outer circumferential surface 4c can be reduced. This reduces the possibility of problems such as the measuring device 1 not being able to be inserted into a hole provided in the mold.

[0051] In polishing step S4, the welded portion 17 and the tip surface 10a are polished so that the tips of the thermocouple 15 (wires 153) are exposed. As a result, when the measuring device 1 is used, the time it takes for heat to reach the pair of wires 53 is shortened. This makes it possible to improve the responsiveness of the measuring device 1.

[0052] In the measuring device 1, a pair of strands 53 are housed in a pair of grooves 61. This stabilizes the position of each strand 53 within the housing 4. Multiple measuring devices 1 manufactured by manufacturing method M1 include pieces 6 having substantially the same volume. Therefore, the heat capacity of the tip portion 45 is stabilized, and the time it takes for heat to reach the pair of strands 53 becomes approximately constant. As a result, individual differences in the responsiveness of the measuring device 1 can be reduced.

[0053] [Second Embodiment] Referring to Figure 9, the manufacturing method of the measuring device 1 according to the second embodiment will be described. Figure 9 is a process diagram showing an example of the manufacturing method of the measuring device 1 according to the second embodiment. As shown in Figure 9, manufacturing method M2 mainly differs from manufacturing method M1 in that it includes preparation step S5 and fixing step S6 instead of preparation step S1 and fixing step S2.

[0054] <Preparation process S5> First, preparation step S5 is performed. Preparation step S5 is the process of preparing the structure 20. Structure 20 differs from structure 10 mainly in that it has a tip surface 20a instead of a tip surface 10a, and further has a welded part 9 (see Figure 12(b)). The welded part 9 is provided so as to cover the groove 161 formation area on the front surface 16a of the piece 16. The welded part 9 fixes the piece 16 and the thermocouple 15 (wire 153) on the front surface 16a. The tip surface 20a is the surface that includes the first end 14a. Note that in structure 20, each wire 153 does not have a tip portion 153a. In preparation step S5, the thermocouple 15 is housed between the pair of grooves 161 and the inner surface 14d of the housing 14 by inserting the piece 16 into the housing 14. Preparation step S5 includes insertion step S51, fixing step S52, and insertion step S53.

[0055] <Insertion process S51> The insertion process S51 will be described in detail with reference to Figures 10(a) and 10(b). Figure 10(a) is a plan view illustrating the insertion process S51 in Figure 9. Figure 10(b) is a cross-sectional view showing a section along the line B1-B1 in Figure 10(a). As shown in Figures 10(a) and 10(b), the insertion process S51 is the process of inserting the thermocouple 15 into the piece 16. In the insertion process S51, for example, the tip of the thermocouple 15 is inserted into a pair of grooves 161 from the back surface 16b or the side surface 16c. At this time, the thermocouple 15 is inserted into the piece 16 such that the respective tip 153a of the pair of strands 153 protrudes from the front surface 16a to the outside of the piece 16.

[0056] <Fixed process S52> Following the insertion step S51, the fixing step S52 is performed. The fixing step S52 will be described in detail with reference to Figures 11(a) and 11(b). Figure 11(a) is a plan view illustrating the fixing step S52 in Figure 9. Figure 11(b) is a cross-sectional view showing a section along the line B2-B2 in Figure 11(a). As shown in Figures 11(a) and 11(b), the fixing step S52 is a step in which the thermocouple 15 is fixed to the piece 16 by auxiliary welding at the front surface 16a.

[0057] Auxiliary welding is performed in the portion of the front surface 16a where a pair of grooves 161 are formed. The auxiliary welding joins the spool 16 and the thermocouple 15 at the front surface 16a. For example, a YAG laser is used for auxiliary welding. The auxiliary welding forms a welded joint 9. Specifically, the pair of wires 153 and the front surface 16a melt and become one, thereby forming the welded joint 9. At this time, the tip portion 153a melts away due to the auxiliary welding.

[0058] <Insertion process S53> Following the fixing process S52, the insertion process S53 is performed. The insertion process S53 will be described in detail with reference to Figures 12(a) and 12(b). Figure 12(a) is a plan view illustrating the insertion process S53 in Figure 9. Figure 12(b) is a cross-sectional view showing a section along the line B3-B3 in Figure 12(a). As shown in Figures 12(a) and 12(b), the insertion process S53 is the process of inserting the integrated piece 16 and thermocouple 15 into the housing 14.

[0059] In insertion step S53, for example, the integrated piece 16 and thermocouple 15 are inserted into the housing 14 from the second end 4b of the housing 14. At this time, the thermocouple 15 is housed in the pair of grooves 161. The piece 16 is then inserted into the housing 14 until its front surface 16a is flush with the first end 14a. This houses the thermocouple 15 (a pair of wires 153) between the pair of grooves 161 and the inner surface 14d of the housing 14. At this time, the front surface 16a is exposed from the first end 14a. Alternatively, the piece 16 may be inserted into the housing 14 such that the front surface 16a is positioned slightly inside the housing 14 relative to the first end 14a. In other words, the piece 16 may be inserted into the housing 14 such that the tips of the pair of wires 153 do not protrude from the first end 14a to the outside of the housing 14.

[0060] As described above, in the preparation step S5, the thermocouple 15 is inserted into the piece 16 (insertion step S51), and the thermocouple 15 is fixed to the piece 16 (fixing step S52). Subsequently, the integrated piece 16 and thermocouple 15 are inserted into the housing 14, so that the thermocouple 15 is housed between the pair of grooves 161 and the inner surface 14d of the housing 14 (insertion step S12), and the structure 20 is manufactured.

[0061] <Fixed process S6> Following the preparation step S5, the fixing step S6 is performed. The fixing step S6 is a step in which the piece 16 is fixed to the housing 14 by first welding at the tip surface 20a, similar to the fixing step S2. The tip surface 20a includes the first end 14a, the front surface 16a, and the welded part 9. The housing 14 and the piece 16 are joined at the tip surface 20a by first welding. Note that the piece 16 and the thermocouple 15 are already joined at the front surface 16a, so after the first welding is performed, the housing 14, the piece 16, and the thermocouple 15 (a pair of strands 153) are joined at the tip surface 20a.

[0062] The first welding is performed on the tip surface 20a, inside the outer edge 146 of the first end 14a. Specifically, the first welding is performed along the boundary between the housing 14 and the piece 16 on the tip surface 20a. Since this boundary is circular in shape with respect to the central axis CL, the first welding is performed circumferentially. The first welding forms a welded portion 17. Specifically, the welded portion 17 is formed when the first end 14a, the front surface 16a, and the welded portion 9 on the tip surface 20a melt and become one.

[0063] The fixing process S3 and the polishing process S4 are the same as in the manufacturing method M1, so their explanation is omitted. Thus, the measuring device 1 is manufactured.

[0064] In preparation step S5, with the thermocouple 15 housed in the pair of grooves 161, the thermocouple 15 is fixed to the piece 16 by auxiliary welding at the front surface 16a of the piece 16. Then, the piece 16 and thermocouple 15 are inserted into the housing 14 so that the front surface 16a is exposed from the first end 14a, thereby housing the thermocouple 15 between the pair of grooves 161 and the inner surface 14d of the housing 14. According to preparation step S5, the thermocouple 15 and the pair of grooves 161 are aligned in the width direction of the grooves 161, and then the piece 16 and thermocouple 15 are aligned along the grooves 161. Therefore, since the alignment in two axes (the width direction of the grooves 161 and the length direction of the grooves 161) is performed individually, the manufacturing of the measuring device 1 can be simplified compared to the case where the thermocouple 15 is inserted into a hole provided in the housing.

[0065] [Differentiation] Embodiments of the present disclosure have been described in detail above. However, the manufacturing method of the measuring device and the measuring device according to the present disclosure are not limited to the embodiments described above. Various modifications are possible to the manufacturing method of the measuring device and the measuring device according to the present disclosure without departing from the spirit thereof.

[0066] For example, if sufficient bonding strength is obtained between the housing 14 and the piece 16 in fixing step S2 or fixing step S6, fixing step S3 may be omitted.

[0067] In the fixing process S3, the second welding may be performed on the outer surface 14c of the housing 14 other than the groove portion 47. In this case, the outer surface 14c of the housing 14 does not need to have a groove portion 47.

[0068] [Note] (Clause 1) A step of preparing a structure comprising: a cylindrical housing having a first and second end open in one direction; a thermocouple extending in the one direction within the housing; and a columnar piece provided within the housing, exposed from the first end, and holding the thermocouple; A step of fixing the piece to the housing by first welding at the tip surface of the structure including the first end, A step of polishing the welded portion and the tip surface formed by the first welding, Includes, The aforementioned piece has a side facing the inner surface of the housing, Each of the aforementioned side surfaces is provided with a pair of grooves that penetrate the piece in one direction, A method for manufacturing a measuring device, wherein in the step of preparing the structure, the thermocouple is housed between the pair of grooves and the inner surface of the housing by inserting the piece into the housing.

[0069] (Article 2) The method for manufacturing a measuring device according to Clause 1, wherein in the step of preparing the structure, the thermocouple is inserted into the housing, and then the piece is inserted into the housing so that the thermocouple is housed between the pair of grooves and the inner surface of the housing.

[0070] (Article 3) The method for manufacturing a measuring device according to Clause 1, wherein in the step of preparing the structure, the thermocouple is housed in the pair of grooves, and after the thermocouple is fixed to the front surface of the piece by auxiliary welding, the piece and the thermocouple are inserted into the housing such that the front surface is exposed from the first end, thereby housing the thermocouple between the pair of grooves and the inner surface of the housing.

[0071] (Article 4) A method for manufacturing a measuring device according to any one of Clauses 1 to 3, wherein the first welding is performed inside the outer edge of the first end.

[0072] (Article 5) The method for manufacturing a measuring device according to Clause 4, wherein the first welding is performed along the boundary between the housing and the piece on the tip surface.

[0073] (Article 6) A method for manufacturing a measuring device according to any one of Clauses 1 to 5, further comprising the step of fixing the piece to the housing by a second welding on the outer surface of the housing.

[0074] (Article 7) The outer circumferential surface of the housing is provided with grooves, The method for manufacturing the measuring device according to Clause 6, wherein the second welding is performed in the groove.

[0075] (Clause 8) A method for manufacturing a measuring device according to any one of Clauses 1 to 7, wherein in the step of polishing the welded portion and the tip surface, the welded portion and the tip surface are polished so that the tip of the thermocouple is exposed. [Explanation of symbols]

[0076] 1... Measuring device, 2... Tube, 3... Crimping ring, 4... Housing, 5... Thermocouple, 6... Piece, 7... Welded part, 8... Welded part, 9... Welded part, 10... Structure, 14... Housing, 15... Thermocouple, 16... Piece, 17... Welded part, 20... Structure, 41... Base end, 42... Flange, 43... Cylinder part, 44... Cylinder part, 45... Tip, 46... Outer edge, 47... Groove, 51... Covering, 52... Covering, 53... Strand, 61... Groove 145...tip, 146...outer edge, 153...strand, 161...groove, 1a...tip surface, 4a...first end, 4b...second end, 4c...outer surface, 4d...inner surface, 6a...front, 6b...back, 6c...side, 1 0a...tip surface, 14a...first end, 14c...outer surface, 14d...inner surface, 16a...front surface, 16b...back surface, 16c...side surface, 20a...tip surface, 53c...tip, M1...manufacturing method, M2...manufacturing method.

Claims

1. A step of preparing a structure comprising: a cylindrical housing having a first and second end open in one direction; a thermocouple extending in the one direction within the housing; and a columnar piece provided within the housing, exposed from the first end, and holding the thermocouple; A step of fixing the piece to the housing by first welding at the tip surface of the structure including the first end, A step of polishing the welded portion and the tip surface formed by the first welding, Includes, The aforementioned piece has a side facing the inner surface of the housing, Each of the aforementioned side surfaces is provided with a pair of grooves that penetrate the piece in one direction, A method for manufacturing a measuring device, wherein in the step of preparing the structure, the thermocouple is housed between the pair of grooves and the inner surface of the housing by inserting the piece into the housing.

2. The method for manufacturing a measuring device according to claim 1, wherein in the step of preparing the structure, after the thermocouple is inserted into the housing, the piece is inserted into the housing so that the thermocouple is housed between the pair of grooves and the inner surface of the housing.

3. The method for manufacturing a measuring device according to claim 1, wherein in the step of preparing the structure, the thermocouple is housed in the pair of grooves, and after the thermocouple is fixed to the front surface of the piece by auxiliary welding, the piece and the thermocouple are inserted into the housing such that the front surface is exposed from the first end, thereby housing the thermocouple between the pair of grooves and the inner surface of the housing.

4. The method for manufacturing a measuring device according to any one of claims 1 to 3, wherein the first welding is performed inside the outer edge of the first end.

5. The method for manufacturing a measuring device according to claim 4, wherein the first welding is performed along the boundary between the housing and the piece on the tip surface.

6. A method for manufacturing a measuring device according to any one of claims 1 to 3, further comprising the step of fixing the piece to the housing by a second welding on the outer surface of the housing.

7. The outer circumferential surface of the housing is provided with grooves, The method for manufacturing a measuring device according to claim 6, wherein the second welding is performed in the groove portion.

8. A method for manufacturing a measuring device according to any one of claims 1 to 3, wherein in the step of polishing the welded portion and the tip surface, the welded portion and the tip surface are polished so that the tip of the thermocouple is exposed.

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