阅读说明：本技术 多层卷绕管的成形装置以及多层卷绕管的成形方法 (Device and method for forming multilayer wound pipe ) 是由 小林荣树 高安弘幸 根岸淳 鹤见政俊 饭村启幸 山下雄辅 津田理博 新村洋佑 照沼直 于 2019-04-26 设计创作，主要内容包括：在多层卷绕管的成形装置中,以夹着作为成形对象的金属板的方式相互对向的一对成形辊沿着所述金属板的进给方向配置有多对,通过多对所述成形辊来将所述金属板弯曲并成形成卷状绕巻的卷绕管,具有金属制的心轴,所述心轴具有：轴,其沿着所述进给方向延伸,被配置于卷状绕卷的所述金属板的内侧,位于所述进给方向的上游的一端侧被保持；以及加工部,其被设于所述轴的与所述一端侧相反侧的另一端侧,具有从所述进给方向的上游朝向下游扩径的锥形部,在通过多对所述成形辊中位于所述进给方向的下游侧的所述一对成形辊来夹着卷状绕卷的所述金属板的位置,配置有所述加工部的所述锥形部。(In a forming apparatus for a multilayer wound pipe, a plurality of pairs of forming rolls are arranged along a feeding direction of a metal plate to be formed so as to face each other with the metal plate interposed therebetween, and the metal plate is bent by the plurality of pairs of forming rolls to form a wound coil, and the forming apparatus includes a metal mandrel including: a shaft that extends in the feeding direction, is disposed inside the metal sheet wound in a roll, and is held at one end side upstream in the feeding direction; and a processing portion provided on the other end side of the shaft opposite to the one end side and having a tapered portion that expands in diameter from upstream to downstream in the feeding direction, wherein the tapered portion of the processing portion is disposed at a position where the pair of forming rolls located on the downstream side in the feeding direction sandwich the metal sheet wound in a roll.)

1. A forming apparatus for a multilayer wrapped pipe, wherein a plurality of pairs of forming rolls are arranged along a feeding direction of a metal sheet to be formed so as to face each other with the metal sheet interposed therebetween, and the metal sheet is bent by the plurality of pairs of forming rolls to form a wrapped pipe in a coiled form,

the metal mandrel is provided with: a shaft that extends in the feeding direction, is disposed inside the metal sheet wound in a roll, and is held at one end side upstream in the feeding direction; and a processing portion provided on the other end side of the shaft opposite to the one end side and having a tapered portion that expands in diameter from upstream to downstream in the feeding direction,

the tapered portion of the processing portion is disposed at a position where the metal sheet wound in a roll is sandwiched by the pair of forming rollers located on the downstream side in the feeding direction among the plurality of pairs of forming rollers.

2. The apparatus of claim 1,

the processed portion has a cylindrical portion extending from an end of the tapered portion toward the opposite side from the shaft with the same diameter.

3. The apparatus according to claim 1 or 2, wherein,

a moving device for moving the mandrel along the feeding direction is also provided,

the mobile device has: a holding portion that holds the one end side of the shaft and is movable to an upstream side and a downstream side in the feeding direction; and a driving source for moving the holding portion.

4. The apparatus of claim 3,

the mobile device further has: a sensor that detects a tension acting on the shaft via the holding portion; and a control unit that controls the drive source based on the tension detected by the sensor and adjusts a position of the holding unit in the feeding direction.

5. A method of forming a multilayer wound pipe using the apparatus for forming a multilayer wound pipe according to any one of claims 1 to 4,

the metal plate is bent and wound into a roll shape,

the overlapped portion of the metal sheets wound in a roll is pressed by the pair of forming rollers and the tapered portion of the processing portion located on the downstream side in the feeding direction of the metal sheets.

Technical Field

The present disclosure relates to a forming apparatus of a multilayer wound pipe and a forming method of a multilayer wound pipe.

Background

From the past, there has been known a forming apparatus for forming a multilayer wound pipe by winding a strip-shaped metal plate into a roll shape by a plurality of pairs of forming rolls (see, for example, japanese patent application laid-open No. 11-342418).

In the forming apparatus of japanese patent application laid-open No. 11-342418, a pair of forming rollers positioned on the downstream side in the sheet metal feeding direction among a plurality of pairs of forming rollers and a processing section of a mandrel arranged inside a sheet metal to be rolled up are used to press the overlapped portions of the sheet metal to be rolled up in a roll shape, thereby bringing the overlapped surfaces into close contact with each other.

Disclosure of Invention

Problems to be solved by the invention

However, in japanese patent application laid-open No. 11-342418, the shape of the mandrel processed portion is a bulge shape that bulges outward in the radial direction, and the overlapped portion of the metal sheet that is wound in a roll shape is pressed between the maximum outer diameter portion of the processed portion and the pair of forming rollers. Here, in the case where there is unevenness in the thickness of the metal sheet, the processing section of the mandrel and the forming roll tend to cause unevenness in the pressing pressure applied to the overlapped portion of the metal sheet wound in a roll. Thus, if the pressing pressure is not uniform, the adhesion between the overlapping surfaces of the metal plates wound in a roll may be reduced. When the adhesion between the overlapping surfaces is reduced, voids (gaps) may be generated between the overlapping surfaces of the metal sheets wound in a roll in the heating step after the forming step.

In view of the above circumstances, an object of the present disclosure is to provide a multilayer wound pipe forming apparatus and a multilayer wound pipe forming method, which can make the pressure applied to the overlapped portion of the metal plates wound in a roll uniform even if the metal plates have uneven thickness.

Means for solving the problems

In one aspect of the present disclosure, a forming apparatus for a multilayer wound pipe, in which a plurality of pairs of forming rolls are arranged along a feeding direction of a metal plate to be formed so as to face each other with the metal plate interposed therebetween, and the metal plate is bent by the plurality of pairs of forming rolls to form a wound pipe wound in a roll shape, includes a metal mandrel, the mandrel including: a shaft that extends in the feeding direction, is disposed inside the metal sheet wound in a roll, and is held at one end side upstream in the feeding direction; and a processing portion provided on the other end side of the shaft opposite to the one end side and having a tapered portion that expands in diameter from upstream to downstream in the feeding direction, wherein the tapered portion of the processing portion is disposed at a position where the pair of forming rolls located on the downstream side in the feeding direction sandwich the metal sheet wound in a roll.

A multilayer wound pipe forming method according to another aspect of the present disclosure is a multilayer wound pipe forming method using the multilayer wound pipe forming apparatus according to the one aspect of the present disclosure, wherein a metal plate is wound in a coil shape by bending, and an overlapping portion of the metal plate wound in the coil shape is pressed by a pair of the forming rollers located on a downstream side in a feeding direction of the metal plate and the tapered portion of the processing section.

Effects of the invention

As described above, according to the present disclosure, it is possible to provide a multilayer wound pipe forming apparatus and a multilayer wound pipe forming method capable of making a pressure applied to an overlapping portion of a metal plate wound in a roll uniform even when the metal plate has a non-uniform thickness.

Drawings

Fig. 1 is a schematic configuration diagram of a forming apparatus for a multilayer wound pipe according to an embodiment of the present disclosure.

Fig. 2 is a sectional view of the pair of forming rolls located most downstream in the sheet metal feeding direction of the forming apparatus for a multilayer wound pipe of fig. 1, taken along the axial direction of the mandrel.

Fig. 3 is a schematic configuration diagram showing an operation of winding a metal plate into a roll shape by the forming apparatus for the multilayer wound pipe of fig. 1.

Fig. 4 is a sectional view of the pair of forming rolls located most downstream in the sheet metal feeding direction of the forming apparatus for a multilayer wound pipe of fig. 3 taken along the axial direction of the mandrel.

Fig. 5 is a sectional view showing a state in which the processed portion of the mandrel is shifted downstream in the feeding direction of the metal plate due to an increase in the thickness of the metal plate in the sectional view shown in fig. 4.

Fig. 6 is a cross-sectional view showing a state in which the machined portion of the mandrel is displaced upstream in the feeding direction of the metal plate due to a decrease in the thickness of the metal plate in the cross-sectional view shown in fig. 4.

Fig. 7 is a sectional view taken along line 7-7X of fig. 4.

Fig. 8 is a cross-sectional view of a multilayer wound pipe manufactured by a method of forming a multilayer wound pipe according to an embodiment of the present disclosure, the cross-sectional view being taken along a direction perpendicular to the axial direction.

Fig. 9 is an enlarged cross-sectional view of a metal plate used in a method of forming a multilayer wound pipe according to an embodiment of the present disclosure.

Fig. 10 is a sectional view (sectional view corresponding to fig. 2) showing a modification of the spindle shown in fig. 2.

Fig. 11 is a sectional view (sectional view corresponding to fig. 4) showing a modification of the spindle shown in fig. 10.

Detailed Description

Hereinafter, a multilayer wound pipe forming apparatus and a multilayer wound pipe forming method according to an embodiment of the present disclosure will be described with reference to the drawings. Note that an arrow M shown in each drawing as appropriate indicates a feeding direction of the metal plate 52.

First, a multilayer wound pipe 50 manufactured by a forming apparatus (hereinafter, appropriately referred to as "forming apparatus") 20 for a multilayer wound pipe according to the present embodiment will be described, and then a forming method using the forming apparatus 20 will be described after a description of the forming apparatus 20.

Fig. 8 shows a multilayer wound tube 50 according to the present embodiment. The multilayer wound pipe 50 is formed by winding a metal plate 52 into a roll shape and joining the overlapping surfaces of the overlapping portions. The multilayer wound pipe 50 of the present embodiment is a double-layer wound pipe. The multilayer wound pipe 50 is used as a piping member of a vehicle (for example, a brake piping).

As shown in fig. 9, the metal plate 52 forming the multilayer winding tube 50 is formed by coating a core material 54 made of a metal material with a coating material 56 made of a metal material having a lower melting point than the core material 54. The metal plate 52 is formed into a strip shape, and the longitudinal direction of the metal plate 52 coincides with the axial direction (direction along the axis) of the multilayer wound tube 50 after forming. Examples of the metal plate 52 include clad steel plates and plated steel plates. As a metal material forming the core material 54, iron, aluminum, or the like may be used. As the metal material forming the clad material 56, copper, aluminum alloy, or the like used as a general brazing material may be used. In the present embodiment, both surfaces of the core material 54 are coated with the coating material 56, but the core material 54 may be coated with only one surface of the coating material 56. In the present embodiment, the metal plate 52 is wound in a coil shape, and then the overlapping surfaces of the overlapping portions are joined by brazing to form the multilayer wound tube 50.

Next, the molding apparatus 20 of the present embodiment will be described.

< Molding apparatus >

As shown in fig. 1 to 4, the forming apparatus 20 is an apparatus for performing roll forming (roll forming), and forms a metal plate 52 into a tubular shape having a predetermined inner diameter by winding the metal plate in a coil.

The molding device 20 includes: a plurality of pairs of forming rolls 22 arranged along a feeding direction of the metal sheet 52 (hereinafter, appropriately abbreviated as "feeding direction"); and a metal mandrel 24 disposed along the feed direction.

(Forming roll)

As shown in fig. 1 and 3, the plurality of pairs of forming rolls 22 are formed by arranging a pair of forming rolls 22 facing each other so as to sandwich a metal plate 52 to be formed, in a plurality of pairs at intervals along the feeding direction. The metal sheet 52 is bent by these forming rollers 22 and wound into a roll shape.

Further, between a pair of forming rolls 22 adjacent in the feeding direction, a plurality of pairs of auxiliary rolls 23 for assisting in bending the metal sheet 52 are arranged.

The pair of forming rollers 22A positioned furthest upstream in the feeding direction of the plurality of pairs of forming rollers 22 functions as a conveying roller, and conveys the metal sheet 52 wound around the drum 58 in the feeding direction from both sheet surface sides.

Further, the pair of forming rollers 22B positioned furthest downstream in the feeding direction of the plurality of pairs of forming rollers 22 functions as a pressure roller, and presses the overlapped portion of the metal sheet 52 wound in a roll between the tapered portion 28A of the mandrel 24 described later, so that the overlapped surfaces 52A, 52B are in contact with each other without a gap. Further, the pair of forming rollers 22B are formed with peripheral grooves 25 into which the metal sheet 52 wound in a roll is inserted. The circumferential groove 25 is formed continuously for one circumference in the circumferential direction of the forming roller 22B.

Further, of the plurality of pairs of forming rollers 22, the plurality of pairs of forming rollers 22C positioned between the pair of forming rollers 22A and the pair of forming rollers 22B function as bending forming rollers for gradually bending the metal sheet 52 from the upstream side toward the downstream side in the feeding direction and winding the metal sheet in a coil shape.

(mandrel)

As shown in fig. 1 and 3, the spindle 24 has a shaft 26 and a processing portion 28.

The shaft 26 extends in the feed direction. Specifically, the shaft 26 extends from between the pair of forming rollers 22A and the pair of forming rollers 22C to the front of the nip portion N of the pair of forming rollers 22B. With this configuration, a part of the shaft 26 (a part on the downstream side in the feeding direction) is disposed inside the metal plate 52 wound in a roll shape. The shaft 26 is formed of a metallic material (e.g., iron). Here, the nip portion N is a position where the sheet metal 52 wound in a roll is sandwiched by a pair of forming rollers 22B located most downstream in the feeding direction.

Further, a disc-shaped reel portion 27 protruding outward in the radial direction from the shaft 26 is formed on the one end 26A side of the shaft 26 located upstream in the feeding direction. The shaft 26 is held by the reel portion 27 by a holding portion 32 of a moving device 30 described later.

The processing portion 28 is provided on the opposite side of the shaft 26 from the one end 26A, that is, on the other end 26B side (the other end 26B in the present embodiment) located downstream in the feeding direction. The processing portion 28 has a tapered portion 28A that expands in diameter from the upstream toward the downstream in the feeding direction. The machined portion 28 is formed of a metal material (e.g., iron) and is welded to the other end 26B of the shaft 26.

The position of the tapered portion 28A of the processing portion 28 along the feed direction of the mandrel 24 is controlled by a moving device 30 described later so as to be positioned at the nip portion N of the pair of forming rollers 22B.

As shown in fig. 1 and 3, the forming apparatus 20 further includes a moving device 30 for moving the mandrel 24 in the feeding direction.

The moving device 30 includes a holding unit 32, a driving source 34, a sensor 36, and a control unit 38.

The holding portion 32 is coupled to the housing 31, and the housing 31 is configured to hold the one end 26A side of the shaft 26 and to be slidable in the feeding direction. The holding portion 32 supports the shaft 26 at one end 26A side and moves in the feeding direction together with the housing 31. The holding portion 32 is provided with an unillustrated engaging portion that engages with the spool portion 27 of the shaft 26. In addition, the spindle 24 also moves together with the movement of the holding portion 32.

The drive source 34 is coupled to the housing 31 via a ball screw mechanism (not shown) for sliding the housing 31. The driving source 34 provides a driving force for moving the holding portion 32 together with the housing 31 in the feeding direction. As the drive source 34, for example, an electric motor (servo motor) may be used. The drive source 34 is controlled by a control unit 38.

The sensor 36 is disposed within the housing. The sensor 36 detects the tension applied to the shaft 26 via the holding portion 32. The information detected by the sensor 36 is sent to the control unit 38.

The control unit 38 controls the output (driving force) of the driving source 34 based on the information on the tension detected by the sensor 36, and adjusts the position of the holding unit 32 in the feeding direction. That is, the control unit 38 can adjust the position of the tapered portion 28A of the processing unit 28 in the feeding direction.

< Molding method >

Next, a method of forming a multilayer wound pipe using the forming apparatus 20 of the present embodiment will be described.

First, before the multilayer winding tube is formed, the size (thickness, inner diameter, etc.) of the multilayer winding tube to be formed is input from an operation unit (not shown) to a storage unit (not shown) of the control unit 38. Based on the size information, the control unit 38 controls the driving source 34 to arrange the tapered portion 28A of the processing unit 28 at the optimum position (optimum position in the feeding direction) of the nip portion N of the pair of forming rollers 22B. The optimum position is determined in advance by calculation based on the size information, or the like. Specifically, the control unit 38 controls the drive source 34 so that the distance L2 (see fig. 2) between the forming roller 22B and the tapered portion 28A is equal to the thickness T of the peripheral wall portion of the multilayer wrapped pipe 50 inputted as the dimensional information, and the tapered portion 28A is arranged at the optimum position of the nip portion N of the pair of forming rollers 22B.

Further, the distances between the pair of forming rollers 22A, the pair of forming rollers 22B, the plurality of pairs of forming rollers 22C, and the plurality of pairs of auxiliary rollers 23 are changed based on the input information. For example, in the pair of forming rollers 22B, the distance L1 between the bottom surfaces of the circumferential groove 25 is changed along the center line CL.

Next, the metal sheet 52 is pulled out from the drum 58, and the leading end portion of the metal sheet 52 is sandwiched between the pair of forming rollers 22A. The pair of forming rolls 22A are rotated in synchronization with each other to convey the clamped metal sheet 52 from the upstream to the downstream in the feeding direction. The metal sheet 52 fed from the pair of forming rolls 22A is bent and wound in a coil by the plurality of pairs of forming rolls 22C and the plurality of pairs of auxiliary rolls 23. At this time, the metal plate 52 is wound in a coil shape so as to surround the shaft 26 of the mandrel 24. Thus, when passing through the plurality of pairs of forming rollers 22C, the metal sheet 52 is wound in a roll shape with a gap at the overlapping portion.

Next, in the nip portion N of the pair of forming rolls 22B, the overlapped portion of the sheet metal 52 wound in a roll is pressed by the pair of forming rolls 22B and the tapered portion 28A of the processing portion 28. Specifically, in the forming apparatus 20, as shown in fig. 4, the roll inside portion of the rolled metal sheet 52 is overlapped with the tapered portion 28A of the processing portion 28 and is expanded in diameter, and as shown in fig. 7, the overlapped portion of the rolled metal sheet 52 is pressed inside and outside the roll by the pair of forming rolls 22B and the tapered portion 28A of the processing portion 28 in a state where the overlapped surfaces 52A, 52B of the overlapped portion of the rolled metal sheet 52 are in contact without a gap (in other words, in a state of being in close contact). Since the overlapped portion after the pressing is before the joining, the rolled metal sheet 52 shown in fig. 4 and 5 passes through the maximum diameter portion of the tapered portion 28A while being expanded in diameter after the pressing.

Here, when the thickness T of the metal plate 52 is thicker than the reference plate (in the present embodiment, half the input thickness) as shown in fig. 5, the friction force generated when the roll inner portion of the metal plate 52 wound in a roll overlaps the tapered portion 28A of the processing portion 28 becomes large, and the tension force F acting on the shaft 26 held at the one end 26A side also becomes large. When the tension F acting on the shaft 26 is large, the axial pulling-up (elastic pulling-up) of the metal shaft 26 becomes large, and the shaft is deviated downstream in the feeding direction with respect to the case where the position of the tapered portion 28A is the reference plate thickness (in other words, the shaft is disposed at the optimum position of the nip portion N). In this way, when the position of the tapered portion 28A is deviated downstream, the distance L2 between the forming roller 22B and the tapered portion 28A is separated, and therefore, an increase in the pressing pressure acting on the overlapping portion of the sheet metal 52 wound in a roll between the pair of forming rollers 22B and the tapered portion 28A is suppressed.

On the other hand, as shown in fig. 6, when the thickness T of the metal plate 52 is smaller than the reference plate thickness, the frictional force generated when the roll inner portion of the metal plate 52 wound in a roll overlaps the tapered portion 28A of the processing portion 28 is reduced, and the tension F acting on the shaft 26 held at the one end 26A is also reduced. When the tension F acting on the shaft 26 is small, the axial pull-up (elastic pull-up) of the metal shaft 26 with respect to the reference plate thickness is small, and the position of the tapered portion 28A is shifted upstream in the feeding direction. As described above, when the position of the tapered portion 28A is shifted upstream, the distance L2 between the pair of forming rollers 22B and the tapered portion 28A approaches, and therefore, a decrease in the pressing pressure acting on the overlapping portion of the sheet metal 52 wound in a roll between the forming rollers 22B and the tapered portion 28A is suppressed.

As described above, in the forming apparatus 20, even if the thickness T of the metal plate 52 is not uniform, the pressure applied to the overlapping portion of the metal plate 52 wound in a roll can be made nearly uniform.

The uneven thickness of the metal plate described herein includes uneven thickness due to manufacturing errors, uneven thickness when a metal plate having a thickness that varies in the middle of the longitudinal direction is used as a specification, and the like.

In the present embodiment, the moving device 30 detects the tension F acting on the shaft 26 by the sensor 36, and the control unit 38 controls the drive source 34 based on the tension F detected by the sensor 36 to adjust the position of the holding unit 32 that supports the shaft 26 in the feeding direction. Specifically, when the tapered portion 28A cannot be arranged at the optimum position of the nip portion N of the pair of forming rollers 22B only by elastic lifting of the shaft 26, the tapered portion 28A is arranged at the optimum position of the nip portion N of the pair of forming rollers 22B in consideration of the elastic lifting of the shaft 26 by the moving device 30. This can provide the above-described effect of elastic lifting of the metal shaft 26, and can make the pressure applied to the overlapping portion of the metal plates wound in a roll nearly uniform.

The metal sheet 52 wound around the pair of forming rollers 22B is heated in a post-heating step. By this heating, the overlapped portions of the metal sheets 52 wound in a roll are joined by brazing, and the multilayer wound tube 50 is manufactured. In the multilayer winding pipe 50 manufactured in this way, since the superposed surfaces 52A and 52B of the superposed portions of the metal plates 52 wound in a roll are heated in a state where they are in contact with each other without a gap (i.e., a state where they are in close contact with each other), the occurrence of voids (gaps) between the superposed surfaces 52A and 52B can be suppressed.

Next, the operational effects of the forming apparatus 20 for a multilayer wound pipe according to the present embodiment will be described.

In the forming apparatus 20, as described above, even if the thickness of the metal plate 52 is uneven, the pressure applied to the overlapping portion of the metal plate 52 wound in a roll can be made nearly uniform.

In the forming apparatus 20, since the tapered portion 28A is disposed at an optimum position of the nip portion N of the pair of forming rolls 22B, it is possible to correspond one kind of the mandrel 24 to a plurality of sizes (plate thicknesses) of metal plates. This can reduce the number of types of mandrels 24. By reducing the number of types of mandrels 24 in this way, the work of installing mandrels in the forming apparatus can be reduced for each metal plate size.

Further, since the forming apparatus 20 further includes the moving device 30, the positions of the pair of forming rollers 22B and the tapered portion 28A of the processing portion 28 along the feeding direction can be automatically adjusted before the metal sheet 52 is formed, and the tapered portion 28A can be disposed at the optimum position of the nip portion N of the pair of forming rollers 22B.

Further, in the forming apparatus 20, as described above, the tapered portion 28A is arranged at the optimum position of the nip portion N of the pair of forming rollers 22B by the moving means 30 in consideration of the elastic lifting of the shaft 26. Therefore, in addition to the effect of elastic lifting by the metal shaft 26, the pressure applied to the overlapping portion of the rolled metal sheet 52 can be made nearly uniform.

In the forming apparatus 20 of the foregoing embodiment, the processed portion 28 of the mandrel 24 has the tapered portion 28A, but the present disclosure is not limited to this structure. For example, as in the spindle 60 shown in fig. 10 and 11, the machining portion 62 may have a cylindrical portion 62B extending from an end of the tapered portion 62A toward the opposite side of the shaft 26 with the same diameter. In this case, for example, compared to the case where the cylindrical portion 62B is not provided and the end of the tapered portion is at an acute angle, the pressure acting on the end of the tapered portion 62A is dispersed, and the wear of the mandrel 24 associated with the processing of the metal plate 52 is suppressed.

In the foregoing embodiment, the forming device 20 has the moving device 30, but the present disclosure is not limited to this structure, and the forming device 20 may have the moving device 30. In this case, the tapered portion 28A is disposed at the optimum position of the nip portion N only by the effect of elastic lifting of the shaft 26.

In the above-described embodiment, the tapered portion 28A of the processing portion 28 is arranged at the nip portion N of the pair of forming rollers 22B located most downstream in the feeding direction, but the present disclosure is not limited to this configuration. For example, the tapered portion 28A of the processing portion 28 may be disposed at a downstream position in the feeding direction and at a nip portion N between a pair of forming rollers 22C located upstream of the pair of forming rollers 22B (a second pair of forming rollers 22C from the most downstream). In this case, the metal sheet 52 wound in a roll can be pressed from the second pair of forming rollers 22C on the most downstream side, and the pipe diameter can be finely adjusted by the pair of forming rollers 22B on the most downstream side.

While the embodiments of the present disclosure have been described above with reference to the embodiments, these embodiments are merely examples, and various modifications and implementations are possible without departing from the scope of the present disclosure. Further, it goes without saying that the scope of the claims of the present disclosure is not limited to these embodiments.

With regard to the above embodiments, further, the following appendix is disclosed.

(appendix 1)

A forming apparatus for a multilayer wrapped pipe, wherein a plurality of pairs of forming rolls are arranged along a feeding direction of a metal sheet to be formed so as to face each other with the metal sheet interposed therebetween, and the metal sheet is bent by the plurality of pairs of forming rolls to form a wrapped pipe in a coiled form,

the metal mandrel comprises: a shaft that extends in the feeding direction, is disposed inside the metal sheet wound in a roll, and is held at one end side upstream in the feeding direction; and a processing portion provided on the other end side of the shaft opposite to the one end side and having a tapered portion that expands in diameter from the upstream toward the downstream in the feeding direction,

the tapered portion of the processing portion is disposed at a position where the metal sheet wound in a roll is sandwiched by the pair of forming rollers located on the downstream side in the feeding direction among the plurality of pairs of forming rollers.

In the forming apparatus of the multilayer coiled pipe of appendix 1, the metal sheet is bent by a plurality of pairs of forming rolls to form a coiled pipe. Accordingly, the overlapped portion of the metal sheet wound in a roll is pressed by the pair of forming rollers and the tapered portion of the processing portion at a position where the metal sheet wound in a roll is sandwiched by the pair of forming rollers located on the downstream side in the metal sheet feeding direction among the plurality of pairs of forming rollers. Specifically, in the above-described forming apparatus, the roll inner portion of the metal sheet wound in a roll is expanded in diameter while overlapping the tapered portion of the processing section, and the overlapped portion of the metal sheet wound in a roll is pressed inside and outside the roll by the pair of forming rolls and the tapered portion of the processing section in a state where the overlapped surfaces of the overlapped portions of the metal sheet wound in a roll are in contact without a gap (in other words, in a state of close contact). Here, when the thickness of the metal plate is uneven and the thickness of the metal plate is thicker than the reference thickness, a friction force generated when the roll inner portion of the metal plate wound in a roll overlaps the tapered portion of the processing portion is large, and a tension force acting on the shaft held on one end side is also large. When the tension acting on the shaft is large, the axial pull-up (elastic pull-up) of the metal shaft becomes large, and the position of the tapered portion is shifted downstream in the feeding direction of the metal plate (hereinafter, appropriately abbreviated as "feeding direction") with respect to the case of the reference plate thickness. In this way, when the position of the tapered portion is shifted downstream in the feeding direction, the distance between the forming roller and the tapered portion is separated, and therefore, an increase in the pressing pressure acting on the overlapping portion of the metal sheets wound in a roll is suppressed between the forming roller and the tapered portion. On the other hand, when the thickness of the metal plate is smaller than the reference thickness, the friction force generated when the roller inner portion of the rolled and wound metal plate overlaps the tapered portion of the processed portion is small, and the tension acting on the shaft is also small. When the tension acting on the shaft is small, the axial pull-up (elastic pull-up) of the metal shaft is small relative to the reference plate thickness, and the position of the tapered portion is shifted upstream in the feeding direction. When the position of the tapered portion is shifted upstream in this way, the distance between the forming roller and the tapered portion is close, and therefore a decrease in the pressing pressure acting on the overlapping portion of the metal sheet wound in a roll is suppressed between the forming roller and the tapered portion.

As described above, the forming apparatus of the multilayer wound pipe of appendix 1 can make the pressure applied to the overlapped portion of the rolled and wound metal sheets nearly uniform even if the metal sheets have uneven thickness.

(appendix 2)

The forming apparatus of a multilayer wound pipe according to appendix 1, wherein the worked portion has a cylindrical portion extending from an end of the tapered portion toward the opposite side from the shaft with the same diameter.

In the forming apparatus of the multilayer winding tube of appendix 2, since the processed portion has the cylindrical portion extending from the end of the tapered portion toward the opposite side of the shaft with the same diameter, for example, compared to a case where the tapered portion does not have the cylindrical portion and the end of the tapered portion has an acute angle, the pressure applied to the end of the tapered portion is dispersed, and the abrasion of the mandrel accompanying the processing of the metal plate is suppressed.

(appendix 3)

The forming apparatus of a multilayer wound tube according to appendix 1 or appendix 2, further comprising a moving device that moves the mandrel in the feeding direction,

the mobile device has: a holding portion that holds the one end side of the shaft and is movable to an upstream side and a downstream side in the feeding direction; and a driving source for moving the holding portion.

In the forming apparatus of the multilayer wound tube of appendix 3, since the moving device for moving the mandrel in the feeding direction is further provided, the position of the tapered portion in the feeding direction can be adjusted in accordance with the reference plate thickness of the metal plate. For example, by appropriately controlling the driving source, the positional relationship between the pair of forming rolls and the processing section can be automatically adjusted before the sheet metal is formed.

(appendix 4)

The forming apparatus of a multilayer wound pipe according to appendix 3, wherein the moving means further has: a sensor that detects tension acting on the shaft via the holding portion; and a control unit that controls the drive source based on the tension detected by the sensor and adjusts a position of the holding unit in the feeding direction.

In the forming apparatus of the multilayer take-up tube of appendix 4, the tension acting on the shaft is detected by the sensor, and the driving source is controlled by the control section based on the tension detected by the sensor, thereby adjusting the position of the holding section holding the shaft in the feeding direction. That is, in the sheet metal forming, the positional relationship between the pair of forming rolls and the processing portion is automatically adjusted. This makes it possible to bring the pressure applied to the overlapping portion of the metal plates wound in a roll close to uniformity, in addition to the effect of elastic lifting by the metal shaft.

(appendix 5)

A method of forming a multilayer wound pipe using the apparatus for forming a multilayer wound pipe described in any one of appendix 1 to 4,

the metal plate is wound in a curved shape,

the overlapped portion of the metal sheets wound in a roll is pressed by the pair of forming rollers and the tapered portion of the processing portion located on the downstream side in the feeding direction of the metal sheets.

In the method of forming a multilayer wound pipe of appendix 5, since the apparatus of forming a multilayer wound pipe of any one of appendices 1 to 4 is used, even if the thickness of the metal plate is not uniform, the pressure applied to the inside and outside of the roll at the overlapping portion of the metal plates wound in a roll shape can be made nearly uniform.

In addition, the disclosure of japanese patent application No. 2018-140612, filed on 26.7.2018, is incorporated by reference in its entirety into the present specification.

All documents, patent applications, and technical standards described in the present specification are incorporated by reference into the present specification to the same extent as if each document, patent application, and technical standard was specifically and individually indicated to be incorporated by reference.