JP2011016140A - Method of joining pipe to member to be joined - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of joining a pipe to a member to be joined by which the joining strength between the pipe and the member to be joined is increased and joining is facilitated.SOLUTION: The pipe 1 and the member 6 to be joined are each made from aluminum. The method of joining the pipe 1 to the member 6 to be joined includes a pipe-expansion joining step where the member 6 to be joined is pipe-expansion joined to the pipe 1 by expanding the pipe 1 in a cooled state using a pipe-expansion joining tool 10 arranged in a hollow part 2 of the pipe 1 which is inserted into a through-hole 7 provided in the member 6 to be joined. In the pipe-expansion joining step, the member 6 to be joined is cooled-fit to the pipe 1 by raising the temperature of the pipe 1 on the way of expansion of the pipe 1 or after the expansion.

Description

  The present invention relates to a method for joining a pipe and a member to be joined, which is used when manufacturing automotive parts, piping materials, and the like, a joining device for a pipe and a member to be joined, and a joint structure of a pipe and a member to be joined. .

  In the present specification and claims, the term “aluminum” is used to include both pure aluminum and aluminum alloys unless otherwise specified.

  As a method of manufacturing a double pipe composed of an inner pipe and an outer pipe which are laminated and joined to each other, JP-A-58-25819 (Patent Document 1), JP-A-58-107225 (Patent Document 2). ) Is known. This method is briefly described as follows.

  In the state where the inner pipe and the outer pipe are overlapped with each other, the temperature of the inner pipe is controlled by flowing water filled in the cooled inner pipe. Further, the outer pipe is heated and expanded. Next, when the temperature difference between the inner and outer pipes reaches a predetermined temperature difference, the water flow is stopped. Then, by applying water pressure in the inner pipe, the inner pipe is expanded, and thereby the outer pipe is mechanically joined to the inner pipe to produce a double pipe.

  Further, as a method for joining a member to be joined such as a flange to a pipe, for example, a pipe expansion joining method using a pipe expansion joining tool is known (see, for example, Patent Documents 3 to 9). This pipe expansion joining method will be briefly described as follows.

  The pipe is inserted into an insertion hole provided in the member to be joined, and a pipe expansion joining tool is disposed in the hollow portion of the pipe. The tube expansion joining tool includes a die having a wedge hole portion at the center and divided into a plurality of die segments in the circumferential direction around the wedge hole portion, and a wedge portion for moving each die segment of the die radially outward. And a mandrel having. Next, the mandrel wedge portion is inserted into the die wedge hole portion to move each die segment of the die radially outward of the pipe, and each die segment presses the pipe radially outward. At this time, the pressure on the pipe by each die segment is performed until the pipe is plastically deformed. Thereby, the pipe is expanded. As a result, the member to be joined is expanded and joined to the pipe in a mechanically fixed state.

JP 58-25819 A JP 58-107225 A Japanese Patent Laid-Open No. 4-8818 JP 2007-296569 A JP 2007-283323 A JP 2009-50875 A JP 2009-72825 A JP 2009-90313 A JP 2009-107005 A

  However, the above two joining methods have the following difficulties.

  In the method of joining by expanding the inner pipe with water pressure, the part must be restrained so that the part other than the planned joining part of the inner pipe is not expanded, and the joining work is troublesome. Furthermore, in this method, there is a possibility that the joint strength between the inner pipe and the outer pipe is insufficient.

  In the method of joining using the pipe expansion joining tool, there is a possibility that the joining strength between the pipe and the member to be joined is insufficient.

  The present invention has been made in view of the above-described technical background, and an object of the present invention is to increase the bonding strength between the pipe and the member to be bonded, and further to connect the pipe that can be easily bonded to the member to be bonded. A joining method of a pipe and a member to be joined used in the method, and a joining structure of a pipe and a member to be joined.

  The present invention provides the following means.

[1] An aluminum pipe in a cooled state inserted through an insertion hole provided in the aluminum member to be joined is expanded by a tube expansion joining tool arranged in the hollow portion thereof, whereby the member to be joined to the pipe is obtained. It has a pipe expansion joining process for pipe expansion joining,
In the pipe expansion joining step, the pipe and the member to be joined are characterized by cooling and fitting the member to be joined to the pipe by raising the temperature of the pipe during or after the pipe expanding process. Joining method.

  [2] In the pipe expansion joining step, the pipe is in an uncooled state before the pipe is expanded, and the pipe expansion joining tool in a cooled state comes into contact with the inner peripheral surface of the pipe while the pipe is expanded. The method for joining a pipe and a member to be joined according to claim 1, wherein the pipe is cooled.

  [3] In the pipe expansion joining step, the member to be joined is in a heated state before the pipe is expanded, and the pipe temperature is increased while the pipe is expanded or after the pipe is expanded. The joining method of the pipe and to-be-joined member of Claim 1 or 2 which cool-fit and shrink-fit the to-be-joined member to a pipe by lowering | hanging temperature.

[4] An aluminum pipe inserted into an insertion hole provided in a heated aluminum member to be joined is expanded by a tube expansion joining tool disposed in the hollow portion, whereby the member to be joined to the pipe is processed. It has a pipe expansion joining process for pipe expansion joining,
In the pipe expansion joining step, the pipe to be joined and the pipe to be joined are characterized by shrink-fitting the member to be joined to the pipe by lowering the temperature of the member to be joined during or after the pipe expansion process. Joining method with member.

[5] A tube expansion joining tool that is disposed in a hollow portion of an aluminum pipe inserted into an insertion hole provided in an aluminum member to be bonded, and expands and joins the member to be bonded to the pipe by expanding the pipe. When,
And a cooling means for cooling the pipe. A joining apparatus for joining a pipe and a member to be joined.

  [6] The cooling means has a tool cooling part for cooling the pipe expansion joining tool, and the pipe expansion joining tool cooled by the tool cooling part comes into contact with the inner peripheral surface of the pipe in the course of pipe expansion processing. The apparatus for joining a pipe and a member to be joined according to claim 5, wherein the pipe is cooled.

  [7] The apparatus for joining a pipe and a member to be joined according to claim 5 or 6, further comprising heating means for heating the member to be joined.

[8] A tube expansion joining tool that is disposed in a hollow portion of an aluminum pipe that is inserted into an insertion hole provided in the aluminum member to be joined and that expands and joins the member to be joined to the pipe by expanding the pipe. When,
And a heating means for heating the member to be joined.

  [9] A pipe and a to-be-coated member characterized in that the to-be-joined member is expanded and joined to the pipe while being cooled and fitted into the through-hole provided in the to-be-joined member made of aluminum. Bonding structure with bonding member.

  [10] The joined structure of a pipe and a member to be joined according to claim 9, wherein the member to be joined is further shrink-fitted to the pipe.

  [11] A pipe and a piece to be welded, in which the member to be joined is expanded and joined to the pipe in a state where the aluminum pipe is inserted into the insertion hole provided in the member to be joined made of aluminum. Bonding structure with bonding member.

  The present invention has the following effects.

  According to the invention of [1], since the member to be joined is expanded and joined to the pipe in the pipe expanding and joining process, and the member to be joined is further cooled and fitted to the pipe, the pipe and the member to be joined are expanded. It is joined by the pressure contact force due to and the pressure contact force due to the cooling fit. Thereby, the joint strength of a pipe and a to-be-joined member can be raised.

  In addition, since the pipe and the member to be joined are both made of aluminum, embrittlement due to cooling does not occur. Therefore, the bonding strength between the pipe and the member to be bonded can be maintained firmly.

  Of course, since it is not necessary to constrain the part other than the part to be joined of the pipe so that the pipe is not expanded, joining can be easily performed.

  Furthermore, in the conventional joining method using water pressure, the pipe cannot be expanded until the pipe is filled with water. However, in the present invention, such time is not necessary, so that the joining time can be shortened. .

  In the invention of [2], since the pipe expansion joining tool in the cooled state is brought into contact with the inner peripheral surface of the pipe while the pipe is being expanded, the pipe is brought into the cooled state. Can be cooled down. Therefore, it is not necessary to cool the entire pipe, and the cost and time required for cooling can be reduced.

  In the invention of [3], since the member to be joined is cooled and shrink-fitted on the pipe, the pipe and the member to be joined are pressed by a pipe expanding process, pressed by a cooling fit, and further pressed by a shrink fit. Are joined together. Thereby, the joint strength of a pipe and a to-be-joined member can further be raised.

  According to the invention of [4], since the member to be joined is expanded and joined to the pipe in the pipe expansion joining step, and further, the member to be joined is shrink-fitted to the pipe, the pipe and the member to be joined are expanded. It is joined by the pressure contact force due to and the pressure contact force due to shrink fitting. Here, in the pipe expansion joining process, the pipe expansion joining tool abuts on the inner peripheral surface of the pipe and the outer peripheral surface of the pipe abuts on the inner peripheral surface of the insertion hole of the member to be joined during pipe expansion processing. The heat of the joining member is conducted from the member to be joined through the pipe and escapes to the tube expansion joining tool. Therefore, it is difficult for the pipe to become hot. Therefore, the member to be joined can be firmly shrink-fitted into the pipe.

  Of course, since it is not necessary to constrain the part other than the part to be joined of the pipe so that the pipe is not expanded, joining can be easily performed.

  Furthermore, in the conventional joining method using water pressure, the pipe cannot be expanded until the pipe is filled with water. However, in the present invention, such time is not necessary, so that the joining time can be shortened. .

  According to the inventions [5] to [8], there is provided a joining device for a pipe and a member to be joined that is preferably used in the joining method of the pipe and the member to be joined according to the inventions [1] to [4]. Can be provided.

  According to the invention of [9], it is possible to provide a joined structure of a pipe having a high joining strength and a member to be joined.

  According to the invention of [10], it is possible to provide a joined structure of a pipe and a member to be joined having extremely high joining strength.

  According to the invention of [11], it is possible to provide a joined structure of a pipe having a high joining strength and a member to be joined.

FIG. 1 is a perspective view of a joint structure of a pipe and a member to be joined that are manufactured by the joining method according to the first embodiment of the present invention. FIG. 2 is a longitudinal sectional view of the joint structure. FIG. 3 is a longitudinal sectional view of a state before joining a member to be joined to a pipe using the joining device according to the first embodiment of the present invention. 4 is a cross-sectional view taken along line XX in FIG. FIG. 5 is a half-longitudinal sectional view showing a state in which the pipe expansion joining tool of the joining apparatus is in contact with the pipe during the pipe expansion processing. FIG. 6 is a semi-longitudinal sectional view showing a state when the pipe is expanded. FIG. 7 is a semi-longitudinal sectional view of the state when the pipe expansion process is finished. FIG. 8 is a longitudinal sectional view of a state before a member to be joined is joined to a pipe using the joining device according to the second embodiment of the present invention. FIG. 9 is a semi-longitudinal sectional view showing a state when the pipe expansion process is finished.

  Next, several embodiments of the present invention will be described below with reference to the drawings.

  1-7 is a figure explaining 1st Embodiment of this invention. In FIG. 3, 40 is a joining apparatus according to the first embodiment.

  1 and 2, reference numeral 50 denotes a joining structure manufactured by joining a member 6 to be joined to the pipe 1 using the joining device 40 of the first embodiment.

  The pipe 1 is used for, for example, an automobile steering support beam, a steering column holder, a muffler, a frame, a propeller shaft, a suspension arm, other automobile parts, or a piping material.

  The pipe 1 is straight, and the outer peripheral surface 1a and the inner peripheral surface 1b have a circular cross section. Further, the pipe 1 has a hollow portion 2 having a circular cross section extending in the axial direction (that is, the length direction). The inner diameter, outer diameter, and wall thickness of the pipe 1 are all set constant in the axial direction of the pipe 1.

  The pipe 1 is made of aluminum. In the present invention, aluminum may be either a heat-treatable alloy or a non-heat-treatable alloy. In this embodiment, for example, it is assumed that aluminum is a heat-treatable alloy. Further, in the present invention, the pipe 1 may be made of an extruded material, a drawn material, or a rolled material, or may be manufactured by other methods.

  The member 6 to be joined is used, for example, as a flange attached to another member (not shown) or as a bracket. The member 6 to be joined has a relatively thick plate shape, and more specifically, an annular plate shape. A fastener insertion hole 9 such as a bolt insertion hole is provided on the outer peripheral portion of the joined member 6 as an attachment portion attached to another member. However, in this invention, the to-be-joined member 6 is not limited to what is used as a flange or a bracket, In addition, you may have a stay, for example.

  The member 6 to be joined is made of aluminum. In the present invention, aluminum may be either a heat-treatable alloy or a non-heat-treatable alloy. In this embodiment, for example, it is assumed that aluminum is a heat-treatable alloy. Furthermore, in this invention, the to-be-joined member 6 may consist of an extruded material, a drawing material, or a rolled material, and may be manufactured by the other method.

  An insertion hole 7 through which the pipe 1 is inserted is provided through the center of the member 6 to be joined. The cross-sectional shape of the insertion hole 7 is a shape corresponding to the cross-sectional shape of the outer peripheral surface 1a of the pipe 1, that is, a circular shape.

  The length of the pipe 1 is set within a range of 50 to 2000 mm, for example, the inner diameter thereof is set within a range of 20 to 400 mm, and the wall thickness thereof is set within a range of 0.5 to 15 mm, for example.

  However, in the present invention, the dimensions of the pipe 1 are not limited to being within the above-described range, and are variously set according to the purpose of use of the pipe 1.

  The outer diameter of the member 6 to be joined is set within a range of 30 to 500 mm, for example. The diameter of the insertion hole 7 of the member to be joined 6 is set to be, for example, 0.1 to 3 mm larger than the outer diameter of the pipe 1 in a state before being expanded. Thereby, the pipe 1 can be inserted into the insertion hole 7 in a loose insertion manner. When the length along the pipe axis direction of the inner peripheral surface 8 of the insertion hole 7 of the joined member 6 is defined as the width of the inner peripheral surface 8, the width of the inner peripheral surface 8 is set within a range of 2 to 50 mm, for example. Has been.

  However, in this invention, each dimension of each site | part of the to-be-joined member 6 is not limited to being in said range, but is set variously according to the intended purpose of the to-be-joined member 6. .

  In this joined structure 50, the member to be joined 6 is expanded and joined to the pipe 1 and cooled with the pipe 1 inserted into the insertion hole 7 of the member to be joined 6.

  The configuration of the joint structure 50 will be described in detail as follows.

  As shown in FIG. 2, the insertion portion 3 into the insertion hole 7 of the pipe 1 is expanded so that the outer peripheral surface of the insertion portion 3 is in pressure contact with the inner peripheral surface 8 of the insertion hole 7 of the member 6 to be joined. Thus, the pipe 1 is plastically deformed so as to bulge outward in the radial direction. And the force in the radial direction of the pipe 1 is always acting on the to-be-joined member 6 by the elastic restoring force of the to-be-joined member 6 accumulate | stored at the time of this pipe expansion process. Furthermore, the member 6 to be joined is cooled and fitted to the pipe 1. Therefore, the member 6 to be joined is joined to the pipe 1 very firmly.

  Furthermore, the axially both sides vicinity parts 4 and 4 of the insertion part 3 of the pipe 1 among the full length area | regions of the pipe 1 are each the state which each bulged locally in the radial outward direction of the pipe 1 by pipe expansion processing. It is plastically deformed. Therefore, a bulging portion S for retaining with a circular arc shape is formed in each neighboring portion 4 so as to extend in the circumferential direction of the pipe 1. The member 6 to be joined is joined to the pipe 1 while being sandwiched between the bulging portions S and S in the axial direction of the pipe 1. Therefore, the detachment strength of the joined member 6 with respect to the pipe 1 is enhanced by the bulging portions S and S. The bulging amount of the bulging portion S is, for example, 0.5 to 10 mm. The width of the bulging portion S is, for example, 1 to 30 mm.

  In the present invention, the cross-sectional shape of the bulging portion S is not limited to an arc shape, but may be a triangular shape, a quadrangular shape, or the like. Furthermore, the bulging amount and the width of the bulging portion S are not limited to being within the above range.

  Next, the structure of the joining apparatus 40 of 1st Embodiment is demonstrated below.

  As shown in FIG. 3, the joining device 40 includes a tube expansion joining tool 10, a cooling unit 20, and the like.

  The pipe expansion joining tool 10 includes a die 11, a mandrel 16, and the like.

  As shown in FIGS. 3 and 4, the die 11 is substantially cylindrical. Therefore, the cross-sectional shape of the die 11 is a substantially circular shape. Furthermore, the die 11 is made of, for example, tool steel or cemented carbide.

  A wedge hole 15 is provided in the center of the die 11 so as to be coaxial with the center axis of the die 11 and penetrate in the axial direction of the die 11. The wedge hole portion 15 has a conical shape or a polygonal pyramid shape. In the first embodiment, the wedge hole portion 15 has a polygonal pyramid shape. Therefore, the cross-sectional shape of the wedge hole portion 15 is a regular square shape (see FIG. 4).

  Further, as shown in FIG. 4, the die 11 is divided into a plurality of die segments 12 equally in the circumferential direction around the wedge hole portion 15. In the first embodiment, the number of divisions of the die 11 is four. The die segments 12 of the die 11 have the same configuration.

  As shown in FIG. 3, the mandrel 16 has a wedge portion 17 corresponding to the wedge hole portion 15 of the die 11. The wedge portion 17 is made of, for example, tool steel or cemented carbide, and is integrally formed in a tapered shape at the tip portion of the mandrel 16. The wedge portion 17 has a conical shape or a polygonal pyramid shape. In the first embodiment, the wedge portion 17 has a polygonal pyramid shape. Therefore, the cross-sectional shape of the wedge portion 17 is a regular square shape. The taper angle of the wedge part 17 is set equal to the taper angle of the wedge hole part 15 of the die 11 and is set within a range of 1 to 30 °, for example. However, in the present invention, the taper angles of the wedge part 17 and the wedge hole part 15 are not limited to being within the above-mentioned range.

  Connected to the base end of the mandrel 16 is a mandrel driving unit 19 that moves the mandrel 16 in a direction in which the wedge 17 is inserted into the wedge hole 15 of the die 11. In the first embodiment, the mandrel drive unit 19 moves the wedge part 17 in the insertion direction with respect to the wedge hole part 15 by pressing the mandrel 16 in the axial direction, and a hydraulic cylinder ( (Not shown).

  The mandrel 16 is configured to move each die segment 12 of the die 11 radially outward of the pipe 1 by inserting the wedge portion 17 into the wedge hole portion 15 of the die 11 disposed in the hollow portion 2 of the pipe 1. It is.

  The mandrel drive unit 19 has a control unit (not shown) for controlling the amount of insertion of the wedge portion 17 into the wedge hole portion 15, that is, the amount of pressing stroke of the drive rod of the hydraulic cylinder. The movement amount of the die segment 12 in the radially outward direction of the pipe 1 is adjusted by controlling the pressing stroke amount of the driving rod by the control unit of the mandrel driving unit 19.

  Each die segment 12 of the die 11 is moved in the radially outward direction of the pipe 1 by the wedge portion 17 of the mandrel 16, thereby pressing the insertion portion 3 and both neighboring portions 4 and 4 of the pipe 1 in the radially outward direction, Thereby, these portions 3, 4, and 4 are plastically deformed and expanded.

  As shown in FIG. 3, two pressing protrusions 13 extending in the circumferential direction of the die 11 are formed on the pressing surface of the die segment 12 (that is, the outer surface facing the pipe inner peripheral surface 1 b side of each die segment 12). , 13 are formed apart from each other in the axial direction of the die 11. The cross-sectional shape of the pressing convex portion 13 is an arc shape. Further, a pressing portion 14 is formed between the first pressing convex portions 13 and 13 on the pressing surface of the die segment 12.

  Both pressing convex parts 13 and 13 press both side neighboring parts 4 and 4 of the insertion part 3 of the pipe 1 in the radially outward direction of the pipe 1 during tube expansion processing, and their shapes and dimensions are set to be equal to each other. .

  The pressing part 14 presses the insertion portion 3 of the pipe 1 in the radially outward direction of the pipe 1 during tube expansion processing.

  The cooling means 20 includes a tool cooling unit 21 that cools each die segment 12 of the die 11 of the pipe expansion joining tool 10. And the cooling means 20 cools each die segment 12 beforehand by the tool cooling part 21, and each die segment 12 cooled in the middle of pipe expansion processing of the pipe 1 contacts the inner peripheral surface 1b of the pipe 1. Thus, the heat of the pipe 1 is conducted and absorbed by each die segment 12, thereby cooling the pipe 1. That is, the cooling means 20 is not a system that directly cools the pipe 1 but a system that cools the pipe 1 via each die segment 12 of the pipe expansion joining tool 10. However, in the present invention, the cooling means 20 does not exclude the type of cooling the pipe 1 directly.

  Inside each die segment 12, a cooling medium flow path through which a cooling medium for cooling the die segment 12 circulates is provided extending in a U shape. Arrows Y in FIGS. 3 to 6 indicate the flow direction of the cooling medium.

  The tool cooling unit 21 includes a cooling medium supply tank 22 and a cooling medium recovery tank 23. The cooling medium supply tank 22 and the inlet portion 28 a of the cooling medium flow path 28 of each die segment 12 are connected via a cooling medium supply pipe 24. The cooling medium recovery tank 23 and the outlet portion 28 b of the cooling medium flow path 28 of each die segment 12 are connected via a cooling medium discharge pipe 25. In the tool cooling section 21, the cooling medium from the cooling medium supply tank 22 is supplied into the cooling medium flow path 28 from the inlet section 28a of the cooling medium flow path 28 through the supply pipe 24, and then the cooling medium flow. It is configured to be recovered from the outlet portion 28 b of the passage 28 through the discharge pipe 25 to the cooling medium recovery tank 23. In this way, the die segment 12 is cooled by causing the cooling medium to flow through the cooling medium flow passage 28. An opening / closing valve 26 is interposed in the cooling medium supply pipe 24. Further, the valve 26 also has a function of adjusting the supply amount of the cooling medium, that is, functions as a flow rate adjusting valve.

  As the cooling medium, a cooling liquid, a cooling gas, or the like is used. Specifically, a cooling medium made of liquid air, liquid nitrogen, or cooling air is used.

  In the present invention, each die segment 12 may be cooled by blowing cooling air from the nozzle to each die segment 12 of the die 11 of the pipe expansion joining tool 10.

  Next, the joining method of the pipe 1 and the to-be-joined member 6 using the said joining apparatus 40 is demonstrated below. In addition, joining shall be performed in the normal temperature atmosphere.

  As shown in FIG. 3, the pipe 1 is inserted into the insertion hole 7 of the member 6 to be joined. At this time, the temperature of the pipe 1 and the temperature of the bonded member 6 are both normal. Further, by opening the opening / closing valve 26 of the tool cooling unit 21 of the cooling means 20, the cooling medium is supplied from the cooling medium supply tank 22 to each die segment 12 of the die 11 of the tube expansion joining tool 10 (that is, the cooling medium is supplied to the cooling medium). This causes each die segment 12 to cool. A desirable cooling temperature of the die segment 12 by the cooling medium will be described later.

  And the die | dye 11 of the pipe expansion joining tool 10 is arrange | positioned in the position corresponding to the to-be-joined member 6 in the hollow part 2 of the pipe 1. FIG. In this state, the die 11 is arranged so that the central axis thereof coincides with the central axis Z of the pipe 1. Further, the mandrel 16 of the pipe expansion joining tool 10 is arranged so that the central axis of the wedge portion 17 coincides with the central axis Z of the pipe 1.

  Subsequently, the wedge part 17 of the mandrel 16 is inserted into the wedge hole part 15 of the die 11 by operating the mandrel driving part 19. As a result, as shown in FIG. 5, each die segment 12 of the die 11 is moved radially outward of the pipe 1 and abuts against the inner peripheral surface 1 b of the pipe 1. Then, the heat of the pipe 1 is conductively absorbed by each die segment 12 from the contact portion between each die segment 12 (more specifically, the pressing convex portion 13 of each die segment 12) and the inner peripheral surface 1 b of the pipe 1. As a result, the pipe 1 is locally cooled at the contact portion with each die segment 12 and in the vicinity thereof. The portion where the pipe 1 is locally cooled substantially coincides with the pipe expansion scheduled portion of the pipe 1, that is, the insertion portion 3 and the adjacent portions 4 and 4. The pipe 1 is cooled to substantially the same temperature as that of the die segment 12. A desirable cooling temperature of the pipe 1 will be described later. By cooling the pipe 1 in this way, the outer diameter of the pipe 1 is reduced.

  With the pipe 1 cooled as described above, the wedge portion 17 of the mandrel 16 is continuously inserted into the wedge hole portion 15 so that the outer peripheral surface of the insertion portion 3 of the pipe 1 becomes the inner periphery of the insertion hole 7 of the member 6 to be joined. The pipe 1 is pressed radially outward by each die segment 12 of the die 11 so as to be pressed against the surface 8. The pressing is performed until the insertion portion 3 and the adjacent portions 4 and 4 of the pipe 1 are plastically deformed. As a result, as shown in FIG. 6, the pipe 1 is expanded, and as a result, the bonded member 6 is expanded and joined to the pipe 1 [expanded joining step].

  Thereafter, the wedge portion 17 of the mandrel 16 is extracted from the wedge hole portion 15 of the die 11 in order to finish the pipe expansion process of the pipe 1. Then, as shown in FIG. 7, each die segment 12 is separated from the inner peripheral surface 1 b of the pipe 1 and is not in contact with the inner peripheral surface 1 b of the pipe 1. That is, the cooling of the pipe 1 is stopped simultaneously with the end of the pipe 1 expansion process. Thereafter, the supply of the cooling medium is stopped by closing the opening / closing valve 26, thereby stopping the cooling of each die segment 12.

  Then, the temperature of the pipe 1 gradually increases so as to reach the normal temperature, and the outer diameter of the pipe 1 gradually increases accordingly. Thereby, the press-contact force of the pipe 1 and the to-be-joined member 6 increases. Then, when the temperature of the pipe 1 returns to room temperature, the member 6 to be joined is securely cooled and fitted to the pipe 1. In the present invention, in order to shorten the time required for the temperature of the pipe 1 to return to the normal temperature, the pipe 1 may be heated by an arbitrary heating device so that the temperature of the pipe 1 becomes the normal temperature.

  In this joining method, at the time of pipe expansion processing, the insertion portion 3 of the pipe 1 is pressed and plastically deformed by the pressing portion 14 of each die segment 12 so as to bulge outward in the radial direction of the pipe 1. The adjacent side portions 4 and 4 of the insertion portion 3 of the pipe 1 are pressed and plastically deformed by the both pressing projections 13 and 13 of each die segment 12 in a state of bulging in the radially outward direction of the pipe 1. As a result, a bulging portion S having an arcuate cross section is formed in each neighboring portion 4 so as to extend in the circumferential direction of the pipe 1.

  In this joining method, it is desirable to cool the pipe 1 so that the temperature difference between the pipe 1 and the member to be joined 6 is 100 ° C. or more. By doing so, the tightening allowance of the cooling fit becomes about 0.1 mm or more, and thereby it is possible to surely improve the joining force by the cooling fit. Specifically, when the cooling temperature of the pipe 1 is exemplified, the cooling temperature of the pipe 1 is set in a range of −70 to −20 ° C. Further, the cooling temperature of the die segment 12 is set to substantially the same temperature as the cooling temperature of the pipe 1.

  In the above joining method, the cooling of the pipe 1 is stopped simultaneously with the end of the pipe 1 expansion process. However, in the present invention, the cooling of the pipe 1 may be stopped while the pipe 1 is being expanded. As a cooling stop method, the cooling of the pipe 1 is stopped by stopping the supply of the cooling medium to the die segment 12 immediately after each die segment 12 of the die 11 contacts the inner peripheral surface 1b of the pipe 1. Is exemplified.

  The joining method of the first embodiment has the following advantages.

  While the member to be joined 6 is expanded and joined to the pipe 1 in the pipe expansion joining process, and the member 6 to be joined is cooled and fitted to the pipe 1, the pipe 1 and the member to be joined 6 are pressed by the pipe expansion process. And further with a pressure contact force by cooling fitting. Thereby, the joint strength of the pipe 1 and the to-be-joined member 6 can be raised.

  In addition, since the pipe 1 and the member to be joined 6 are both made of aluminum, embrittlement due to cooling does not occur. Therefore, the joining strength between the pipe 1 and the member 6 to be joined can be maintained firmly.

  Of course, since it is not necessary to restrain the site | part so that site | parts other than the joining plan part of the pipe 1 may not be expanded, joining can be performed easily.

  Furthermore, in the conventional joining method using water pressure, the pipe 1 cannot be expanded until the pipe 1 is filled with water. However, in the present invention, such time is not necessary, so that the joining time can be shortened. it can.

  Furthermore, the pipe 1 is brought into the cooling state by directly contacting the inner peripheral surface 1b of the pipe 1 with each die segment 12 in the cooling state while the pipe 1 is being expanded without directly cooling the pipe 1. Only the pipe expansion processing scheduled parts (3, 4, 4) can be locally cooled. Therefore, it is not necessary to cool the entire pipe, and the cost and time required for cooling can be reduced.

  However, the present invention does not exclude direct cooling of the entire pipe 1 or the pipe expansion scheduled portion of the pipe 1. Examples of the method of directly cooling the entire pipe 1 and the pipe expansion scheduled portion of the pipe 1 include a method of cooling the whole pipe 1 and the pipe expansion scheduled portion of the pipe 1 by blowing cooling air from a nozzle.

  8 and 9 are diagrams illustrating a second embodiment of the present invention. In these drawings, the same parts as those in the first embodiment are denoted by the same reference numerals.

  In 2nd Embodiment, the joining apparatus 40 is provided with the pipe expansion joining tool 10, the cooling means 20, and the heating means 30 which heats the to-be-joined member 6 further.

  The heating means 30 includes a heat generating portion 32 and a power source 31 that supplies heat generation electricity to the heat generating portion 32. The heat generating part 32 is attached to the member to be joined 6 or arranged in the vicinity of the member to be joined 6, and is attached to the outer peripheral part of the member to be joined 6 in this embodiment. The heat generating part 32 contains an electric heating wire (not shown). The heating means 30 is configured to heat the joined member 6 from the heat generating portion 32 by supplying the power of the power source 31 to the heat generating portion 32 (that is, the electric heating wire) and causing the heat generating portion 32 to generate heat. .

  In addition, the heat generating part 32 is electrically connected to the power source 31 via the feeder line 33. The power supply line 33 is provided with an ON / OFF switch 34 for turning on or off the power supply from the power source 31 to the heat generating unit 32. The power supply 31 has an adjustment function (not shown) that adjusts the amount of power supplied to the heat generating unit 32.

  The inner diameter of the insertion hole 7 of the joined member 6 before being heated by the heating means 30 is set to be, for example, 0.1 to 0.5 mm larger than the outer diameter of the pipe 1 before being expanded. ing.

  Next, a method of joining the pipe 1 and the member 6 to be joined using the joining device 40 will be described below with a focus on differences from the first embodiment. In addition, joining shall be performed in the normal temperature atmosphere.

  In the second embodiment, as shown in FIG. 8, before the pipe 1 is expanded, electricity is supplied from the power source 31 to the heat generating portion 32 of the heating means 30, so that the member 6 to be bonded is previously formed by the heat generating portion 32. Keep heated. Thereby, the internal diameter of the insertion hole 7 of the to-be-joined member 6 increases. A desirable heating temperature of the member to be bonded 6 will be described later.

  In this state, the pipe 1 is expanded as in the joining method of the first embodiment.

  Thereafter, the wedge portion 17 of the mandrel 16 is extracted from the wedge hole portion 15 of the die 11 in order to finish the pipe expansion process of the pipe 1. Then, as shown in FIG. 9, each die segment 12 is separated from the inner peripheral surface 1 b of the pipe 1 and is not in contact with the inner peripheral surface 1 b of the pipe 1. That is, the cooling of the pipe 1 is stopped simultaneously with the end of the pipe 1 expansion process. Thereafter, the supply of the cooling medium is stopped by closing the opening / closing valve 26, thereby stopping the cooling of each die segment 12.

  Then, the temperature of the pipe 1 gradually increases so as to reach the normal temperature, and the outer diameter of the pipe 1 gradually increases accordingly. Thereby, the press-contact force of the pipe 1 and the to-be-joined member 6 increases. Then, when the temperature of the pipe 1 returns to room temperature, the member 6 to be joined is securely cooled and fitted to the pipe 1.

  Further, the power supply to the heat generating portion 32 is stopped by turning off the switch 34 of the heating means 30 at the same time or after the pipe expanding process of the pipe 1 is finished, thereby stopping the heating of the member 6 to be joined. .

  Then, the temperature of the member 6 to be joined is gradually lowered so as to reach room temperature, and the diameter of the insertion hole 7 of the member to be joined 6 is reduced accordingly. Thereby, the press-contact force of the pipe 1 and the to-be-joined member 6 increases. And the to-be-joined member 6 is firmly shrink-fitted on the pipe 1 when the temperature of the to-be-joined member 6 returns to normal temperature.

  In this joining method, it is desirable that the pipe 1 is cooled and the joined member 6 is heated so that the temperature difference between the pipe 1 and the joined member 6 is 100 ° C. or more. In particular, when the member to be bonded 6 is made of a heat-treatable aluminum alloy, the member to be bonded 6 is heated so that the temperature of the member to be bonded 6 is lower than the heat treatment temperature of the heat-treatable aluminum alloy. It is desirable in that the strength of itself can be maintained, and the joining strength between the pipe 1 and the member to be joined 6 can be maintained. By doing this, the total amount of the interference allowance for cooling fitting and the interference allowance for shrink fitting is about 0.1 mm or more, and thereby it is possible to surely improve the joining force by the cooling and shrink fitting. Specifically, the heating temperature of the member to be bonded 6 is exemplified. When the member to be bonded 6 is made of a heat-treatable aluminum alloy, the heating temperature of the member to be bonded 6 is set within a range of 100 to 250 ° C. When the member to be bonded 6 is made of a non-heat-treatable aluminum alloy, the heating temperature of the member to be bonded 6 is set within a range of 100 to 400 ° C.

  In the above joining method, the heating of the joined member 6 is stopped simultaneously with or after the end of the pipe 1 expansion process. However, in the present invention, the heating of the member to be joined 6 may be stopped while the pipe 1 is being expanded. As a heating stop method, the heating of the joined member 6 is stopped by stopping the power supply to the heat generating portion 32 after each die segment 12 of the die 11 abuts on the inner peripheral surface 1b of the pipe 1. Is exemplified.

  In the joined structure 50 produced by joining by the joining method of the second embodiment, the member 6 to be joined is expanded and joined to the pipe 1 and is cooled and shrink-fitted. Therefore, the joining strength between the pipe 1 and the member 6 to be joined is extremely high.

  The bonding method of the second embodiment has the following advantages in addition to the advantages of the bonding method of the first embodiment.

  Since the member to be joined 6 is cooled and shrink-fitted to the pipe 1, the pipe 1 and the member to be joined 6 are joined together by a pressure contact force due to tube expansion processing, a pressure contact force due to cooling fit, and a pressure contact force due to shrink fit. The Thereby, the joint strength of the pipe 1 and the to-be-joined member 6 can further be raised.

  Thus, the present invention is not limited to the first and second embodiments, and can be variously changed.

  For example, in the said 2nd Embodiment, the pipe 1 and the to-be-joined member 6 are joined by the press-contact force by a pipe expansion process, the press-contact force by cooling fitting, and the press-contact force by shrink fitting. However, in this invention, the pipe 1 and the to-be-joined member 6 may be joined not by the press contact force by cooling fitting but by the press contact force by pipe expansion processing and the press contact force by shrink fitting. In this case, the pipe 1 and the member to be joined 6 are joined as follows. The following method is a modification of the second embodiment.

  That is, the joining of the pipe 1 and the member 6 to be joined is performed according to the joining method of the second embodiment except that the die segments 12 are not cooled.

  According to this modification, the member to be bonded 6 is expanded and joined to the pipe 1 in the pipe expanding and joining step, and the member 6 to be joined is shrink-fitted to the pipe 1. Therefore, the pipe 1 and the to-be-joined member 6 are joined by the press-contact force by a pipe expansion process, and also the press-contact force by shrink fitting. Here, in the pipe expansion joining process, each pipe segment 1 is in contact with the inner peripheral surface 1b of the pipe 1 while the pipe 1 is being expanded, and the outer peripheral surface 1a of the pipe 1 is within the insertion hole 7 of the member 6 to be joined. Since it contacts the peripheral surface 8, the heat of the member to be bonded 6 is conducted from the member to be bonded 6 through the pipe 1 and escapes to each die segment 12. Therefore, it is difficult for the pipe 1 to become high temperature. Therefore, the joined member 6 can be firmly shrink-fitted into the pipe 1. Therefore, the joint strength between the pipe 1 and the member to be joined 6 can be increased.

  Moreover, in this modification, since each die segment 12 is not cooled, the joining apparatus 40 does not necessarily need to be provided with the cooling means 20.

  Furthermore, the present invention is not limited to the first and second embodiments and modifications described above, and various modifications can be made without departing from the scope of the present invention.

  In the above embodiment, the pipe 1 has a circular cross section. However, in the present invention, the pipe 1 may have a polygonal shape such as a square or hexagonal cross section. In this case, the bonding strength between the pipe 1 and the member to be bonded 6 against the load in the circumferential direction of the pipe 1, that is, the torsional strength between the pipe 1 and the member to be bonded 6 can be increased.

  Further, in the present invention, the pipe 1 has a hollow portion 2 in which a partition wall portion extending in the pipe axial direction for partitioning the hollow portion into a plurality of hollow compartments is formed integrally with the pipe 1, that is, a partition. It may be a pipe with a wall.

  The present invention is used, for example, when manufacturing a steering support beam, a steering column holder, a muffler, a frame, a propeller shaft, a suspension arm, a camshaft, and other automobile parts of an automobile, or as a product other than an automobile, for example, The present invention can be used for a method of joining a pipe and a member to be joined, a joining device used for the joining method, and a joint structure of a pipe and a member to be used, which are used when manufacturing a piping material.

1: pipe 2: hollow part 6: member to be joined 7: insertion hole 8: inner peripheral surface 10 of the insertion hole: pipe expansion joining tool 11: die 12: die segment 16: mandrel 20: cooling means 21: tool cooling part 28: Cooling medium flow passage 30: Heating means 32: Heat generating unit 40: Joining tool 50: Joining structure Y: Flow direction of cooling medium

Claims (11)

The pipe to be joined is expanded and joined to the pipe by expanding the cooled aluminum pipe inserted into the insertion hole provided in the aluminum to-be-joined member with a pipe-expansion joining tool disposed in the hollow portion. It has a pipe expansion joining process,
In the pipe expansion joining step, the pipe and the member to be joined are characterized by cooling and fitting the member to be joined to the pipe by raising the temperature of the pipe during or after the pipe expanding process. Joining method.   In the pipe expansion joining step, the pipe is in an uncooled state before the pipe is expanded, and the pipe expansion joining tool in a cooled state comes into contact with the inner peripheral surface of the pipe while the pipe is expanded, thereby cooling the pipe. The joining method of the pipe of Claim 1 and a to-be-joined member made into a state.   In the pipe expansion joining step, the member to be joined is in a heated state before the pipe is expanded, and during or after the pipe is expanded, the temperature of the pipe is increased and the temperature of the member to be decreased is decreased. The joining method of the pipe and to-be-joined member of Claim 1 or 2 which carries out cooling fitting and shrink fitting of the to-be-joined member to a pipe by doing. The pipe to be joined is expanded and joined to the pipe by expanding the aluminum pipe inserted into the insertion hole provided in the heated aluminum joined member with a pipe expansion joining tool disposed in the hollow portion. It has a pipe expansion joining process,
In the pipe expansion joining step, the pipe to be joined and the pipe to be joined are characterized by shrink-fitting the member to be joined to the pipe by lowering the temperature of the member to be joined during or after the pipe expansion process. Joining method with member. A pipe expansion joining tool that is disposed in a hollow portion of an aluminum pipe inserted into an insertion hole provided in the aluminum member to be joined, and expands and joins the member to be joined to the pipe by expanding the pipe; and
And a cooling means for cooling the pipe. A joining apparatus for joining a pipe and a member to be joined.   The cooling means has a tool cooling section for cooling the pipe expansion joining tool, and the pipe expansion joining tool cooled by the tool cooling section abuts on the inner peripheral surface of the pipe while expanding the pipe, thereby The joining apparatus of the pipe and to-be-joined member of Claim 5 which is what cools.   The joining apparatus of the pipe and to-be-joined member of Claim 5 or 6 provided with the heating means which heats to-be-joined member. A pipe expansion joining tool that is disposed in a hollow portion of an aluminum pipe inserted into an insertion hole provided in the aluminum member to be joined, and expands and joins the member to be joined to the pipe by expanding the pipe; and
And a heating means for heating the member to be joined.   A pipe and a member to be joined, wherein the member to be joined is expanded and joined to the pipe while being cooled and fitted in a state where the aluminum pipe is inserted into the insertion hole provided in the member to be joined made of aluminum, Bonding structure.   The joined structure of a pipe and a member to be joined according to claim 9, wherein the member to be joined is further shrink-fitted to the pipe.   A pipe and a member to be joined, wherein the member to be joined is expanded and joined to the pipe and shrink-fitted while the aluminum pipe is inserted into an insertion hole provided in the aluminum member to be joined, Bonding structure.

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