Aluminum pipe expanding device, head unit for aluminum pipe expanding device, head body for aluminum pipe expanding device, aluminum pipe expanding method, and aluminum pipe for refrigerant

Abstract

To enable expansion of an aluminum pipe for refrigerant to a predetermined size easily and highly accurately.SOLUTION: An aluminum pipe expanding device for expanding an aluminum pipe for refrigerant, comprises: a body portion which has a movable lever on which a lever operation is performed; and a head unit which is attached to the body portion and has a pipe expanding portion that expands the aluminum pipe by expanding in a cylinder of the aluminum pipe according to a lever operation. The aluminum pipe has an outer diameter dimension before pipe expansion equal to a standard outer diameter dimension before expansion of a copper pipe for refrigerant, and an inner diameter dimension before expansion smaller than an inner diameter dimension before expansion of the copper pipe for refrigerant. The pipe expanding portion has an outer diameter dimension before pipe expansion smaller than an inner diameter of the aluminum pipe before pipe expansion, and has an outer diameter dimension after the pipe expansion larger than the outer diameter of the aluminum pipe before the pipe expansion.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an aluminum tube expanding device, a head unit for an aluminum tube expanding device, a head body for an aluminum tube expanding device, an aluminum tube expanding method, and an aluminum tube for a refrigerant.

Background Art

[0002] Conventionally, in order to connect refrigerant pipes used in air conditioners and the like, a technique of expanding one pipe using an expanding device is known. For example, Patent Document 1 below discloses a device including a tube expander and a sleeve attached to the tube expander, and by operating a press handle of the tube expander to expand the outer diameter of a head provided on the sleeve, the tube can be expanded by the head.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, conventionally, copper tubes have generally been used as refrigerant pipes. For this reason, the head of the expanding device is manufactured in accordance with the size standard of copper tubes.

[0005] On the other hand, in recent years, from the viewpoints of weight reduction and cost reduction, using aluminum tubes as refrigerant pipes has been considered. The strength of aluminum is about 1 / 3 of the strength of copper. In order to make the yield strength of the aluminum tube equivalent to that of the copper tube, it is necessary to make the wall thickness of the aluminum tube thicker than that of the copper tube. Therefore, when the outer diameter dimension of the aluminum tube is the same as the outer diameter dimension of the copper tube, it is necessary to make the inner diameter dimension of the aluminum tube smaller than the inner diameter dimension of the copper tube. Note that in Japanese piping standards, it is common to unify the outer dimensions.

[0006] However, in the conventional pipe expanding device, since the outer diameter dimension of the pipe expanding portion of the head is manufactured in accordance with the inner diameter dimension of the copper pipe, the pipe expanding portion of the head cannot be inserted into the opening of the aluminum pipe. Therefore, when expanding an aluminum pipe using the conventional pipe expanding device, it is necessary to use a head that is slightly smaller in size. In this case, play may occur between the head and the aluminum pipe, or the expansion of the aluminum pipe may be insufficient, so the expansion of the aluminum pipe to a predetermined size cannot be performed easily and with high precision.

Means for Solving the Problems

[0007] An aluminum pipe expanding device according to an embodiment is an aluminum pipe expanding device for expanding an aluminum pipe for a refrigerant, and includes a main body portion having a movable lever for which a lever operation is performed, and a head unit that is attached to the main body portion and has an expanding portion for expanding the aluminum pipe by expanding within the cylinder of the aluminum pipe in accordance with the lever operation. The aluminum pipe has an outer diameter dimension before expansion that is the same as the standard outer diameter dimension of a copper pipe for a refrigerant before expansion, and an inner diameter dimension before expansion that is smaller than the inner diameter dimension of a copper pipe for a refrigerant before expansion. The expanding portion has an outer diameter dimension before expansion that is smaller than the inner diameter of the aluminum pipe before expansion and an outer diameter dimension after expansion that is larger than the outer diameter of the aluminum pipe before expansion.

Advantages of the Invention

[0008] According to an embodiment, the expansion of the aluminum pipe for a refrigerant to a predetermined size can be performed easily and with high precision.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Mode for Carrying Out the Invention

[0010] Hereinafter, an embodiment will be described with reference to the drawings. In each of the embodiments described below, for convenience, the direction in which the fixed lever 120 extends is defined as the X-axis direction. Also, the direction in which the taper pin 135 reciprocates (the axial direction of the central axis AX) is defined as the Y-axis direction. Further, the direction orthogonal to the X-axis direction and the Y-axis direction (the axial direction of the rotation axis 132 of the movable lever 130) is defined as the Z-axis direction.

[0011] (Schematic Configuration of Aluminum Tube Expanding Device 100) FIG. 1 is an external perspective view of an aluminum tube expanding device 100 according to an embodiment. FIG. 2 is a five-sided view of the aluminum tube expanding device 100 according to an embodiment. FIG. 3 is an enlarged view of a head unit 140 included in the aluminum tube expanding device 100 according to an embodiment.

[0012] The aluminum tube expanding device 100 shown in FIGS. 1 and 2 is for expanding an aluminum tube in order to enable joining (brazing connection) of aluminum tubes for a refrigerant used in an air conditioner or the like.

[0013] As shown in FIGS. 1 and 2, the aluminum tube expanding device 100 includes a main body part 100A and a head unit 140. The main body part 100A has a base part 110, a fixed lever 120, a movable lever 130, and a taper pin 135.

[0014] The base 110 is a metal block-shaped member that supports each component (fixed lever 120, movable lever 130, taper pin 135, and head unit 140). The base 110 generally has a rectangular parallelepiped shape. On the side surface of the base 110 on the positive X-axis side, a pair of fixing portions 111 for fixing the fixed lever 120 are provided protruding. Each of the pair of fixing portions 111 is a flat plate-shaped portion having a constant width in the Y-axis direction and extending linearly in the X-axis direction. The pair of fixing portions 111 are parallel to each other with a constant interval in the Y-axis direction. Further, the base 110 has a space portion 110A between the wall portion on the positive Z-axis side and the wall portion on the negative Z-axis side. Inside the space portion 110A, a pair of rotating members 131 of the movable lever 130 and a rotating shaft 132 of the movable lever 130 are provided. On the side surface of the base 110 on the positive Y-axis side, a columnar convex portion 110B for attaching the head unit 140 is provided protruding.

[0015] The fixed lever 120 is a metal rod-shaped member that extends linearly from the base 110 in the positive X-axis direction. One end portion (the end portion on the negative X-axis side) of the fixed lever 120 is fixed to the pair of fixing portions 111 while being sandwiched between the pair of fixing portions 111 provided on the base 110.

[0016] The movable lever 130 is a metal rod-shaped member that extends linearly from the base 110 in the positive X-axis direction. The movable lever 130 has a pair of rotating members 131 at one end portion (the end portion on the negative X-axis side). The pair of rotating members 131 are fixed to one end portion of the movable lever 130 while sandwiching one end portion of the movable lever 130. Further, the pair of rotating members 131 are pivotally supported rotatably inside the space portion 110A by a round bar-shaped rotating shaft 132 that penetrates the pair of rotating members 131 inside the space portion 110A of the base 110. Thereby, the movable lever 130 is rotatable (that is, lever-operable) in a direction approaching the fixed lever 120 (direction A shown in FIG. 2) and a direction separating from the fixed lever 120 (direction B shown in FIG. 2) with the rotating shaft 132 as the rotation center.

[0017] The tapered pin 135 is a metal and conical member. The tapered pin 135 protrudes from the central opening (not shown) of the convex portion 110B provided in the base portion 110 on the positive Y-axis side on the central axis AX. The tapered pin 135 is provided so as to be movable in the axial direction (Y-axis direction) of the central axis AX within the central opening of the convex portion 110B on the central axis AX. The tapered pin 135 is connected to the rotating member 131 of the movable lever 130 inside the base portion 110. As a result, the tapered pin 135 moves in the Y-axis direction on the central axis AX (inside the central opening of the convex portion 110B) according to the lever operation of the movable lever 130.

[0018] The head unit 140 has a head body 141 and an expansion tube portion 143. The head body 141 is a metal and columnar member that operably supports the expansion tube portion 143. The center of the head body 141 is located on the central axis AX. The head body 141 has a circular recess 141A (see FIG. 2) on the surface on the base portion 110 side (negative Y-axis side) in a plan view. A screw thread (not shown) is formed on the inner peripheral surface of the recess 141A.

[0019] The expansion tube portion 143 is provided so as to protrude from the head body 141 on the positive Y-axis side coaxially with the central axis AX. It is a metal and generally columnar member. As shown in FIG. 3, the expansion tube portion 143 is divided into six fan-shaped blocks 143A around the central axis AX. Each of the six blocks 143A is provided so as to be movable in the radial direction of the circle centered on the central axis AX. Each of the six blocks 143A is biased radially inward by an annular coil spring 144 disposed so as to surround the expansion tube portion 143 inside the head body 141. A central gap 143B that penetrates the expansion tube portion 143 in the Y-axis direction is formed at the center (on the central axis AX) of the expansion tube portion 143. As a result, the tapered pin 135 can enter the central gap 143B of the expansion tube portion 143. The expansion tube portion 143 is configured such that the outer diameter dimension of the expansion tube portion 143 changes when each of the six blocks 143A moves radially as the tapered pin 135 moves within the central gap 143B.

[0020] The head unit 140 is detachable from the base 110 of the main body 100A. Specifically, in the head unit 140, a concave portion 141A (see FIG. 2) is formed on the surface (the surface on the negative Y-axis side) of the head main body 141 facing the base 110, and the thread formed on the inner peripheral surface of the concave portion 141A is screwed onto the thread formed on the outer peripheral surface of a columnar convex portion 110B (see FIG. 2) protruding from the surface on the positive Y-axis side of the base 110, so that it is fixed to the surface on the positive Y-axis side of the base 110. By being fixed to the surface on the positive Y-axis side of the base 110, the center of the head main body 141 is positioned on the central axis AX.

[0021] As shown in FIGS. 1 and 2, the aluminum tube expanding device 100 according to one embodiment has identification information 101A and 101B that can identify that each of the main body 100A and the head unit 140 is for expanding an aluminum tube. Thereby, the aluminum tube expanding device 100 according to one embodiment can prevent each of the main body 100A and the head unit 140 from being erroneously used for expanding a copper tube, that is, can suppress the adhesion of copper powder, which causes dissimilar metal potential difference corrosion.

[0022] In the example shown in FIGS. 1 and 2, in the main body 100A, identification information 101A consisting of the character string "for aluminum tube" is provided on the movable lever 130. Also, in the example shown in FIGS. 1 and 2, in the head unit 140, identification information 101B consisting of the character string "for aluminum tube" is provided on the head main body 141. As an example, the identification information 101A and 101B are markings. However, it is not limited to this, and the identification information 101A and 101B may be a tape or the like. Also, the identification information 101A and 101B are not limited to those consisting of character strings, and may consist of symbols, figures, etc. that can identify that they are for aluminum tubes.

[0023] (Operation of the aluminum tube expanding device 100) When an opening operation of the movable lever 130 (operation in a direction away from the fixed lever 120) is performed in the aluminum tube expanding device 100 according to an embodiment, the taper pin 135 moves rearward (in the negative Y-axis direction) on the central axis AX. As a result, the taper pin 135 gradually exits rearward (in the negative Y-axis direction) from within the central gap 143B of the expanding portion 143 of the head unit 140. As a result, each of the six blocks 143A of the expanding portion 143 of the head unit 140 gradually moves radially inward by the biasing force of the coil spring 144, and thus the outer diameter of the expanding portion 143 gradually becomes smaller.

[0024] Conversely, in the aluminum tube expanding device 100 according to an embodiment, when a closing operation of the movable lever 130 (operation in a direction approaching the fixed lever 120) is performed, the taper pin 135 moves forward (in the positive Y-axis direction) on the central axis AX. As a result, the taper pin 135 gradually enters forward (in the positive Y-axis direction) into the central gap 143B of the expanding portion 143 of the head unit 140. As a result, each of the six blocks 143A of the expanding portion 143 of the head unit 140 is pushed outward by the taper pin 135 and gradually moves radially outward while resisting the biasing force of the coil spring 144, and thus the outer diameter of the expanding portion 143 gradually becomes larger.

[0025] (Dimension example of the head unit 140) FIG. 4 is a diagram showing an example of the dimensions of the head unit 140 included in the aluminum tube expanding device 100 according to an embodiment. As shown in FIG. 4, the aluminum tube expanding device 100 according to an embodiment includes, as an example, three head units 140 corresponding to the sizes of three aluminum tubes (3 / 8 inch, 4 / 8 inch, and 5 / 8 inch). That is, the sizes of the expanding portions 143 of the three head units 140 are different from each other. The aluminum tube expanding device 100 according to an embodiment can selectively replace the head unit 140 attached to the head unit 140 among these three head units 140 according to the size of the aluminum tube to be expanded. Note that the aluminum tube expanding device 100 according to an embodiment may include four or more head units 140 corresponding to the sizes of four or more aluminum tubes.

[0026] <The first head unit 140> The first head unit 140 corresponds to a 3 / 8-inch aluminum tube. The inner diameter of the 3 / 8-inch aluminum tube before expansion is 7.22 mm. The outer diameter of the 3 / 8-inch aluminum tube before expansion is 9.52 mm, which is the same as the outer diameter of the 3 / 8-inch copper tube before expansion in terms of specifications. That is, the wall thickness of the 3 / 8-inch aluminum tube is 1.15 mm. Thus, the 3 / 8-inch aluminum tube can sufficiently withstand the pressure of the refrigerant. Pipe thickness On the other hand, the outer diameter of the expanding portion 143 of the first head unit 140 before expansion is 6.4 mm, which is slightly smaller than the inner diameter of the 3 / 8-inch aluminum tube before expansion. For this reason, the first head unit 140 can easily insert the expanding portion 143 before expansion into the 3 / 8-inch aluminum tube. Note that the outer diameter of the expanding portion 143 of the first head unit 140 before expansion is preferably 6.2 to 6.6 mm, more preferably 6.3 to 6.5 mm, and still more preferably 6.35 to 6.45 mm.

[0027] Incidentally, the inner diameter of a 3 / 8-inch copper tube is 7.92 mm, and the outer diameter of the flared portion of a conventional head unit for a 3 / 8-inch copper tube is slightly smaller than 7.92 mm. Therefore, the flared portion of a conventional head unit for a 3 / 8-inch copper tube cannot be inserted into a 3 / 8-inch aluminum tube (inner diameter: 7.22 mm) before flaring.

[0028] Further, the outer diameter of the flared portion 143 of the first head unit 140 after flaring is 9.6 mm. Thus, the first head unit 140 can flare the inner diameter of a 3 / 8-inch aluminum tube after flaring to an inner diameter of 9.6 mm, which is larger than the outer diameter (9.52 mm) of the 3 / 8-inch aluminum tube before flaring. As a result, it becomes possible to insert another aluminum tube before flaring into one aluminum tube after flaring.

[0029] In particular, the flared portion 143 of the first head unit 140 has an outer diameter dimension (9.6 mm) after flaring when the operation amount of the lever operation is maximum (that is, when the movable lever 130 is lever-operated in the direction approaching the fixed lever 120 until it abuts). Thereby, the aluminum tube flaring device 100 according to one embodiment can flare a 3 / 8-inch aluminum tube to have a predetermined inner diameter dimension (9.6 mm) with a single lever operation regardless of the skill level of the operator.

[0030] Also, the gap dimension between the outer diameter (9.52 mm) of another aluminum tube before flaring and the inner diameter (9.6 mm) of one aluminum tube after flaring is only 0.08 mm. Therefore, the first head unit 140 can suppress the other aluminum tube before flaring from rattling inside one aluminum tube after flaring. Incidentally, from the viewpoints of suppressing rattling, ease of insertion, workability and certainty of brazing joint, etc., the gap dimension between the outer diameter of the 3 / 8-inch aluminum tube before flaring and the inner diameter of the 3 / 8-inch aluminum tube after flaring is preferably 0.08 to 0. 3 It is preferably 14 mm. That is, it is preferable that the inner diameter of the aluminum tube after flaring is 9.6 to 9.82 mm, and it is preferable that the outer diameter dimension of the flared portion 143 after flaring is 9.6 to 9.82 mm.

[0031] <Second head unit 140> The second head unit 140 corresponds to a 4 / 8-inch aluminum tube. The inner diameter of the 4 / 8-inch aluminum tube before expansion is 9.7 mm. The outer diameter of the 4 / 8-inch aluminum tube before expansion is 12.7 mm, which is the same as the outer diameter of the 4 / 8-inch copper tube before expansion according to the standard. That is, the wall thickness of the 4 / 8-inch aluminum tube is 1.5 mm. Thus, the 4 / 8-inch aluminum tube can sufficiently withstand the pressure of the refrigerant. On the other hand, for the second head unit 140, the outer diameter of the expansion part 143 before expansion is 9.0 mm, which is slightly smaller than the inner diameter of the 4 / 8-inch aluminum tube before expansion. Therefore, the second head unit 140 can easily insert the expansion part 143 before expansion into the 4 / 8-inch aluminum tube. Note that the outer diameter of the expansion part 143 before expansion of the second head unit 140 is preferably 8.8 - 9.2 mm, more preferably 8.9 - 9.1 mm, and even more preferably 8.95 - 9.05 mm.

[0032] Note that the inner diameter of the 4 / 8-inch copper tube is 11.1 mm, and the outer diameter of the expansion part of the conventional head unit for the 4 / 8-inch copper tube is slightly smaller than 11.1 mm. Therefore, the expansion part of the conventional head unit for the 4 / 8-inch copper tube cannot be inserted into the 4 / 8-inch aluminum tube (inner diameter: 9.7 mm) before expansion.

[0033] Also, for the second head unit 140, the outer diameter of the expansion part 143 after expansion is 12.8 mm. Thus, the second head unit 140 can expand the inner diameter of the 4 / 8-inch aluminum tube after expansion to 12.8 mm, which is larger than the outer diameter (12.7 mm) of the 4 / 8-inch aluminum tube before expansion. As a result, it becomes possible to insert the other aluminum tube before expansion into one aluminum tube after expansion.

[0034] In particular, when the operation amount of the lever operation reaches the maximum (that is, when the movable lever 130 is lever-operated in the direction approaching the fixed lever 120 until it hits), the expanded pipe portion 143 of the second head unit 140 has an outer diameter dimension (12.8 mm) after expansion. Thereby, the aluminum pipe expanding device 100 according to one embodiment can expand a 4 / 8-inch aluminum pipe into one having a predetermined inner diameter dimension (12.8 mm) with a single lever operation regardless of the skill level of the operator.

[0035] Also, the gap dimension between the outer diameter (12.7 mm) of another aluminum pipe before expansion and the inner diameter (12.8 mm) of one aluminum pipe after expansion is only 0.1 mm. For this reason, the second head unit 140 can suppress the other aluminum pipe before expansion from rattling inside one aluminum pipe after expansion. From the viewpoints of suppressing rattling, ease of insertion, workability and certainty of brazing joint, etc., the gap dimension between the outer diameter of the 4 / 8-inch aluminum pipe before expansion and the inner diameter of the 4 / 8-inch aluminum pipe after expansion is preferably 0.1 to 0. 4 mm. That is, it is preferable that the inner diameter of the aluminum pipe after expansion is 12.8 to 13.1 mm, and it is preferable that the outer diameter dimension of the expanded pipe portion 143 after expansion is 12.8 to 13.1 mm.

[0036] <The third head unit 140> The third head unit 140 corresponds to a 5 / 8-inch aluminum tube. The inner diameter of the 5 / 8-inch aluminum tube before expansion is 12.28 mm. The outer diameter of the 5 / 8-inch aluminum tube before expansion is 15.88 mm, which is the same as the outer diameter of the 5 / 8-inch copper tube before expansion according to the standard. That is, the wall thickness of the 5 / 8-inch aluminum tube is 1.8 mm. Thus, the 5 / 8-inch aluminum tube can sufficiently withstand the pressure of the refrigerant. On the other hand, for the third head unit 140, the outer diameter of the expansion part 143 before expansion is 11.8 mm, which is slightly smaller than the inner diameter of the 5 / 8-inch aluminum tube before expansion. Therefore, the third head unit 140 can easily insert the expansion part 143 before expansion into the 5 / 8-inch aluminum tube. Note that the outer diameter of the expansion part 143 before expansion of the third head unit 140 is preferably 11.6 - 12.0 mm, more preferably 11.7 - 11.9 mm, and even more preferably 11.75 - 11.85 mm.

[0037] Note that the inner diameter of the 5 / 8-inch copper tube is 13.88 mm, and the outer diameter of the expansion part of the conventional head unit for the 5 / 8-inch copper tube is slightly smaller than 13.88 mm. Therefore, the expansion part of the conventional head unit for the 5 / 8-inch copper tube cannot be inserted into the 5 / 8-inch aluminum tube (inner diameter: 12.28 mm) before expansion.

[0038] Also, for the third head unit 140, the outer diameter of the expansion part 143 after expansion is 16.0 mm. Thus, the third head unit 140 can expand the inner diameter of the 5 / 8-inch aluminum tube after expansion to 16.0 mm, which is larger than the outer diameter (15.88 mm) of the 5 / 8-inch aluminum tube before expansion. As a result, it becomes possible to insert the other aluminum tube before expansion into one aluminum tube after expansion.

[0039] In particular, when the operation amount of the lever operation reaches the maximum (that is, when the movable lever 130 is lever-operated in the direction approaching the fixed lever 120 until it hits), the expanded pipe portion 143 of the third head unit 140 has an outer diameter dimension (12.8 mm) after expansion. Thereby, the aluminum pipe expanding device 100 according to one embodiment can expand a 5 / 8-inch aluminum pipe into a pipe having a predetermined inner diameter dimension (12.8 mm) with a single lever operation regardless of the skill level of the operator.

[0040] Also, the gap dimension between the outer diameter (15.88 mm) of another aluminum pipe before expansion and the inner diameter (16.0 mm) of one aluminum pipe after expansion is only 0.12 mm. Therefore, the third head unit 140 can suppress the other aluminum pipe before expansion from rattling inside one aluminum pipe after expansion. From the viewpoints of suppressing rattling, ease of insertion, workability and reliability of brazing joint, etc., the gap dimension between the outer diameter of the 5 / 8-inch aluminum pipe before expansion and the inner diameter of the 5 / 8-inch aluminum pipe after expansion is preferably 0.1 to 0.4 mm. That is, it is preferable that the inner diameter of the aluminum pipe after expansion is 15.98 to 16.28 mm, and it is preferable that the outer diameter dimension of the expanded pipe portion 143 after expansion is 15.98 to 16.28 mm.

[0041] (A suitable example of the material of each component) FIG. 5 is a diagram showing a suitable example of the material of each component included in the aluminum pipe expanding device 100 according to one embodiment. However, the materials of the components shown in FIG. 5 are just examples, and other materials may be used for each component.

[0042] As shown in FIG. 5, in the aluminum pipe expanding device 100 according to one embodiment, it is preferable to use SUS303, which has relatively high strength and a high rust prevention effect, as the material of the base portion 110 of the main body portion 100A.

[0043] Also, as shown in FIG. 5, in the aluminum tube expanding device 100 according to one embodiment, it is preferable to use A2017 (so-called duralumin), which is a relatively high-strength aluminum alloy, as the material of the fixed lever 120 and the movable lever 130 of the main body portion 100A. Thereby, the aluminum tube expanding device 100 according to one embodiment can achieve sufficient weight reduction while ensuring sufficient strength for the fixed lever 120 and the movable lever 130.

[0044] Also, as shown in FIG. 5, in the aluminum tube expanding device 100 according to one embodiment, it is preferable to use a material having a higher hardness than the tube expanding portion 143 of the head unit 140 as the material of the taper pin 135 of the main body portion 100A. For example, it is preferable to use SKD11 (hardness: HRC58), which is an alloy tool steel with excellent wear resistance. Thereby, the aluminum tube expanding device 100 according to one embodiment can suppress the wear of the taper pin 135 due to the sliding of the taper pin 135 against the tube expanding portion 143 of the head unit 140.

[0045] As shown in FIG. 5, in the aluminum tube expanding device 100 according to one embodiment, it is preferable to use SUS303, which has relatively high strength and a high rust prevention effect, as the material of the head body 141 of the head unit 140.

[0046] Also, as shown in FIG. 5, in the aluminum tube expanding device 100 according to one embodiment, it is preferable to use NAK55 (hardness: HRC40), which is an alloy tool steel with excellent wear resistance, as the material of the tube expanding portion 143 of the head unit 140. Thereby, the aluminum tube expanding device 100 according to one embodiment can suppress the wear of the tube expanding portion 143 due to the sliding of the taper pin 135 against the tube expanding portion 143 of the head unit 140.

[0047] (Method for expanding an aluminum tube by the aluminum tube expanding device 100) FIG. 6 is a flowchart showing the procedure of the aluminum tube expanding method according to one embodiment. FIGS. 7 and 8 are diagrams schematically showing the aluminum tube expanding method according to one embodiment.

[0048] First, as shown in FIG. 7(a), a head unit 140 corresponding to the size of the aluminum tube 10 to be expanded is attached to the base 110 of the main body 100A of the aluminum tube expanding device 100 (step S601: attachment step).

[0049] Next, as shown in FIG. 7(b), with the movable lever 130 of the aluminum tube expanding device 100 open (i.e., in a state where the outer diameter of the expanding portion 143 is the smallest), the expanding portion 143 of the head unit 140 of the aluminum tube expanding device 100 is inserted into the opening of the aluminum tube 10 (step S602: expanding portion insertion step). Here, in the aluminum tube expanding device 100 according to an embodiment, the outer diameter of the expanding portion 143 before expansion is smaller than the inner diameter of the aluminum tube 10 before expansion. Therefore, in the aluminum tube expanding device 100 according to an embodiment, the expanding portion 143 of the head unit 140 can be easily inserted into the opening of the aluminum tube 10.

[0050] Next, as shown in FIG. 7(c), the movable lever 130 of the aluminum tube expanding device 100 is lever-operated in a direction approaching the fixed lever 120 until the operation amount reaches the maximum (i.e., until the movable lever 130 abuts) (step S603: expanding step). As a result, the taper pin 135 moves forward (in the positive Y-axis direction) within the central gap 143B of the expanding portion 143, thereby expanding the outer diameter of the expanding portion 143. As a result, as shown in FIG. 7(c), the opening of the aluminum tube 10 is expanded by the expanding portion 143 to have a predetermined outer diameter. In the expanding step, the expanding portion 143 may be rotated within the opening of the aluminum tube 10 and the expanding operation may be performed multiple times. Thereby, it is possible to suppress the occurrence of steps in the opening of the aluminum tube 10 or the expansion of the opening of the aluminum tube 10 into a distorted circular shape.

[0051] Next, the expanded tube portion 143 of the head unit 140 is pulled out from the opening of the expanded aluminum tube 10 (step S604: pulling-out step). Then, as shown in FIG. 8(a), another aluminum tube 12 is inserted into the opening of the expanded aluminum tube 10 (step S605: aluminum tube insertion step). At this time, it is preferable to remove burrs, cuttings, etc. of the aluminum tubes 10 and 12 and clean the joint portion of the aluminum tubes 10 and 12 for subsequent brazing. Also, at this time, it is preferable to remove the oxide film on the joint portion of the aluminum tubes 10 and 12 using a non-woven fabric or the like.

[0052] Finally, as shown in FIG. 8(b), the aluminum brazing filler metal 14 is melted into the gap between the inner peripheral surface of the expanded aluminum tube 10 and the outer peripheral surface of the other aluminum tube 12 using the aluminum brazing filler metal 14 and the burner 16, thereby brazing and joining the other aluminum tube 12 to the expanded aluminum tube 10 (step S606: joining step).

[0053] Note that the joining step of step S606 is performed, for example, according to the following procedure.

[0054] (Procedure 1) Preheating step The joint portion between the aluminum tube 10 and the aluminum tube 12 is preheated using the burner 16. At this time, since the melting point of the aluminum tube for refrigerant is relatively low at about 640°C, attention is paid to the preheating time, heating temperature, etc. so as not to overheat the joint portion.

[0055] (Procedure 2) Charging step Utilizing the preheating of the joint portion, the aluminum brazing filler metal 14 is melted into the joint portion (the gap between the aluminum tube 10 and the aluminum tube 12). At this time, it is preferable to set the usage amount of the aluminum brazing filler metal 14 to a predetermined suitable usage amount.

[0056] (Procedure 3) Cooling step The joint portion is cooled using the outside air to solidify the aluminum brazing filler metal melted into the joint portion.

[0057] Note that for the joining step in step S606, for example, by using an application as disclosed in Japanese Patent Application Laid-Open No. 2019-141905, brazing joining (working procedure, preheating time, heating temperature, amount of aluminum brazing material 14 used, etc.) may be performed according to voice guidance. Thereby, the operator can accurately perform the brazing joining of the aluminum tube 12 without melting the aluminum tube 12.

[0058] As described above, although one embodiment of the present invention has been described in detail, the present invention is not limited to these embodiments, and various modifications or changes are possible within the scope of the gist of the present invention described in the claims.

Explanation of Reference Numerals

[0059] 100 Aluminum tube expanding device 100A Main body part 101A, 101B Identification information 110 Base part 110A Space part 110B Convex part 111 Fixing part 120 Fixed lever 130 Movable lever 131 Rotating member 132 Rotating shaft 135 Taper pin 140 Head unit 141 Head body 141A Concave part 143 Expanding part 143A Block 143B Central gap 144 Coil spring AX Central axis

Claims

1. An aluminum tube expanding device for expanding an aluminum tube for a refrigerant, comprising: a main body having a movable lever for lever operation; a head unit attached to the main body and having an expanding portion for expanding the aluminum tube by expanding inside the cylinder of the aluminum tube in accordance with the lever operation and comprising: wherein the aluminum tube has an outer diameter dimension before expansion that is the same as the standard outer diameter dimension of a copper tube for a refrigerant before expansion, and has an inner diameter dimension before expansion that is smaller than the inner diameter dimension of the copper tube for the refrigerant before expansion, wherein the expanding portion has an outer diameter dimension before expansion that is smaller than the inner diameter of the aluminum tube before expansion, and has an outer diameter dimension after expansion that is larger than the outer diameter of the aluminum tube before expansion Characterized by an aluminum tube expanding device.

2. Comprising the first head unit for expanding the 3 / 8-inch aluminum tube, wherein the expanding portion of the first head unit has an outer diameter dimension before expansion of 6.2 to 6.6 mm, and has an outer diameter dimension after expansion that is 0.08 to 0.2 mm larger than the outer diameter of the 3 / 8-inch aluminum tube before expansion Characterized by the aluminum tube expanding device according to Claim 1.

3. Comprising the first head unit for expanding the 3 / 8-inch aluminum tube, wherein the expanding portion of the first head unit has an outer diameter dimension before expansion of 6.2 to 6.6 mm, and has an outer diameter dimension after expansion of 9.6 to 9.82 mm Characterized by the aluminum tube expanding device according to Claim 1.

4. Comprising the second head unit for expanding the 4 / 8-inch aluminum tube, wherein the expanding portion of the second head unit has an outer diameter dimension before expansion of 8.8 to 9.2 mm, and has an outer diameter dimension after expansion that is 0.1 to 0.3 mm larger than the outer diameter of the 4 / 8-inch aluminum tube before expansion Characterized by the aluminum tube expanding device according to any one of Claims 1 to 3.

5. Comprising the second head unit for expanding the 4 / 8-inch aluminum tube, wherein the expanding portion of the second head unit has an outer diameter dimension before expansion of 8.8 to 9.2 mm, and has an outer diameter dimension after expansion of 12.8 to 13.1 mm Characterized by the aluminum tube expanding device according to any one of Claims 1 to 3.

6. Comprising the third head unit for expanding the 5 / 8-inch aluminum tube, wherein the expanding portion of the third head unit has an outer diameter dimension before expansion of 11.6 to 12.0 mm, The outer diameter dimension after tube expansion is 0.1 to 0.4 mm larger than the outer diameter of the 5 / 8-inch aluminum tube before tube expansion. The aluminum tube expanding device according to any one of claims 1 to 5, characterized in that.

7. Comprising the third head unit for expanding the 5 / 8-inch aluminum tube, The tube expanding part of the third head unit, The outer diameter dimension before tube expansion is 11.6 to 12.0 mm, The outer diameter dimension after tube expansion is 15.98 to 16.28 mm The aluminum tube expanding device according to any one of claims 1 to 5, characterized in that.

8. The tube expanding part, When the operation amount of the lever operation is maximum, it has the outer diameter dimension after tube expansion. The aluminum tube expanding device according to any one of claims 1 to 7, characterized in that.

9. At least on the head unit, Having identification information that can identify that it is for expanding the aluminum tube. The aluminum tube expanding device according to any one of claims 1 to 8, characterized in that.

10. A head unit for an aluminum tube expanding device for expanding an aluminum tube for a refrigerant, A head body mounted on the main body of the aluminum tube expanding device having a movable lever for lever operation, A tube expanding part provided protruding from the head body, and expanding within the cylinder of the aluminum tube along with the lever operation to expand the aluminum tube. Comprising, The aluminum tube, The outer diameter dimension before tube expansion is the same as the outer diameter dimension in the standard before tube expansion of a copper tube for a refrigerant, The inner diameter dimension before tube expansion is smaller than the inner diameter dimension before tube expansion of the copper tube for a refrigerant, The tube expanding part, Having an outer diameter dimension before tube expansion that is smaller than the inner diameter of the aluminum tube before tube expansion, Having an outer diameter dimension after tube expansion that is larger than the outer diameter of the aluminum tube before tube expansion. A head unit for an aluminum tube expanding device, characterized in that.

11. A head body for an aluminum tube expanding device for expanding an aluminum tube for a refrigerant, Mounted on the main body of the aluminum tube expanding device having a movable lever for lever operation, Holding a tube expanding part for expanding the aluminum tube, Expanding the tube expanding part within the cylinder of the aluminum tube along with the lever operation to expand the aluminum tube, The aluminum tube, The outer diameter dimension before tube expansion is the same as the outer diameter dimension in the standard before tube expansion of a copper tube for a refrigerant, The inner diameter dimension before tube expansion is smaller than the inner diameter dimension before tube expansion of the copper tube for a refrigerant, The tube expanding part, having an outer diameter dimension before tube expansion that is smaller than the inner diameter of the aluminum tube before tube expansion, having an outer diameter dimension after tube expansion that is larger than the outer diameter of the aluminum tube before tube expansion The head body for an aluminum tube expanding device, characterized by the above.

12. An aluminum tube expanding method for expanding an aluminum tube for refrigerant, comprising: a tube expanding part insertion step of inserting a tube expanding part provided in the aluminum tube expanding device into the cylinder of the aluminum tube; a tube expanding step of expanding the aluminum tube by expanding the tube expanding part within the cylinder of the aluminum tube in accordance with a lever operation of a movable lever provided in the aluminum tube expanding device including The aluminum tube has an outer diameter dimension before tube expansion that is the same as the standard outer diameter dimension of a copper tube for refrigerant before tube expansion, has an inner diameter dimension before tube expansion that is smaller than the inner diameter dimension of the copper tube for refrigerant before tube expansion, The tube expanding part has an outer diameter dimension before tube expansion that is smaller than the inner diameter of the aluminum tube before tube expansion, has an outer diameter dimension after tube expansion that is larger than the outer diameter of the aluminum tube before tube expansion The aluminum tube expanding method, characterized by the above.

13. An aluminum tube for refrigerant expanded by the aluminum tube expanding method according to Claim 12.

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