JP3183052B2 - Expansion tube mandrel, expansion method using the same, expansion device, and heat exchanger provided with expanded tube by expansion method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe expanding mandrel used for manufacturing a cross fin coil used as a heat exchanger of an air conditioner, a mechanical pipe expanding method and a pipe expanding apparatus using the mandrel, and The present invention relates to a heat exchanger manufactured by the pipe expansion method.

[0002]

2. Description of the Related Art In a cross fin coil used as a heat exchanger of an air conditioner, a large number of cooling tubes are inserted into a large number of fins in a skewered manner, and the cooling tubes are simultaneously expanded and fixed to the fins. It is manufactured by

[0003] As a tube expansion device used for manufacturing a cross fin coil, a mechanical type is widely used. A conventional mechanical pipe expansion device is shown in FIGS. Although the tube expanding device shown here is of a horizontal type, a tube expanding process is also performed on a vertical tube expanding device according to the same principle.

A conventional mechanical pipe expanding apparatus (horizontal apparatus) includes a horizontal bed 1, a moving frame 4 moving forward and backward between a pair of front and rear fixed frames 2 and 3 provided on the bed 1, 3 and a plurality of mandrels 5, 5... Having a base end connected to the moving frame 4 and a tube expansion head attached to the front end.

[0005] In order to perform tube expansion, first, a cross fin coil before tube expansion is fixed on the head 1 in front of the fixed frame 2. Next, the moving frame 4 is advanced. As a result, a large number of mandrels 5, 5... Move forward through the fixed frame 2 at the same time, and the expansion pipes attached to the ends thereof are pressed into the cooling pipes of the cross fin coils, whereby the cooling pipes are simultaneously expanded. You.

[0006]

In such a conventional mechanical pipe expanding apparatus, the length of the apparatus is increased because a mandrel is required to be removed, and the apparatus length is generally required to be four times the total length of the cross fin coil. It has been. Therefore, there is a problem that the device becomes large.

Further, since the mandrel cannot be inserted unless the cooling pipe is straight, there is a restriction that the cooling pipe cannot process a curved L-shaped or U-shaped cross fin coil as shown in FIG. Due to this restriction, for the L-shaped and U-shaped cross fin coils, the work of expanding the cooling pipe and fixing it to the fins before bending is performed, and then bending the cross fin coil. .

However, according to this work, there is a problem that fin flaws are apt to occur during bending. In the double-row coil, the inner and outer coils must be separated because the inner and outer coils have different bending radii. Therefore, application to a double-row coil is difficult.

[0009] There is a hydraulic expansion device capable of solving these problems, and in fact, this hydraulic expansion device is applied to a large cross fin coil having a total length exceeding 2 m.

However, when the present invention is applied to an L-shaped or U-shaped cross fin coil, since the bending portion of the cooling pipe undergoes work hardening, the expansion of the bending portion becomes insufficient.
Therefore, it is said that the cooling pipe does not sufficiently adhere to the fin in the bent portion, and the performance is reduced by about 5%.

[0011] Above all, alternative fluorocarbons extremely disturb water, so it is difficult to introduce a hydraulic expansion device in the future, and the existing hydraulic expansion device is also switched to a mechanical expansion device. There are some situations that must be done.

[0012] Therefore, development of a small mechanical expansion device applicable to a cross-fin coil after bending has been desired.

It is an object of the present invention to use a mechanical expansion
An object of the present invention is to provide a mandrel for expanding a pipe, which can significantly shorten the length of the apparatus and expand the cross-fin coil after bending.

Another object of the present invention is to provide a pipe expanding method and a pipe expanding apparatus which can be used for a cross-fin coil after bending, in which the length of the apparatus can be significantly reduced while being mechanical.

Still another object of the present invention is to provide a high-performance and economical heat exchanger manufactured by using the expansion method.

[0016]

According to the tube expanding mandrel of the present invention, a number of mandrel pieces which can be inserted into a tube to be expanded are connected in a line so as to be bent at a connecting portion, and a tube expanding head is attached to the end thereof. It is a flexible mandrel.

More specifically , as shown in FIGS. 1 and 2 , the flexible mandrel has a large number of mandrel pieces 11, 11,... Formed as short rods and adjacent mandrel pieces 11, 11 are bent. it is a universal type that can be connected.

Alternatively , as shown in FIGS. 12 and 13, a large number of mandrel pieces 11, 11,... Are formed into spherical bodies, and the spherical bodies are provided with radial through-holes 11d, and wires 14 passing through the through-holes 11d are provided. Is a rosary type in which a large number of mandrel pieces 11, 11... Are connected in a row.

In the rosary type mandrel 10, FIG.
As shown in FIG. 2, a spacer 15 having a through hole 15a in the center thereof through which the wire 14 passes and having spherical receiving seats 15b, 15b at both ends in which the mandrel pieces 11, 11 are in surface contact with each other is connected to an adjacent mandrel piece 11, , 11 are desirably provided.

In the pipe expanding method of the present invention, a longitudinal expansion force is applied to the above-mentioned flexible mandrel from outside the pipe, and the pipe expansion head at the tip is pressed into the pipe.

In the tube expanding method of the present invention, it is desirable that the flexible mandrel be wound around a winding drum and stored.

The expansion device of the present invention includes a winding drum that winds and stores the above-mentioned flexible mandrel, and press-fits the expansion head at the tip of the mandrel into the tube by applying a longitudinal propulsive force to the mandrel from outside the tube. And a mandrel sending mechanism.

According to a ninth aspect of the present invention, there is provided a pipe expanding apparatus comprising: a work table for fixing a cross fin coil to be expanded; It is provided movably in the tube arrangement direction of the coil.

It is desirable that the pipe expansion unit be one that operates a plurality of mandrels synchronously.

According to a tenth aspect of the present invention, the tube expanding unit uses four mandrels, and the delivery paths of the four mandrels are arranged at the four vertices of a diamond.

The mandrel sending mechanism is not only attached to the winding drum, but the winding drum may also serve as the mandrel sending mechanism.

[0027] The tube expanding device according to the eleventh aspect includes a mandrel sending mechanism attached to the winding drum,
The delivery mechanism is a mandrel guide that guides the mandrel in a straight line, a pair of sliders that reciprocate synchronously in the opposite direction along the mandrel guide by a pair of crank mechanisms, and a direction perpendicular to the mandrel guide mounted on each slider. A movable hook pin that fits into a recess provided in each mandrel piece of the mandrel in the mandrel guide by moving.

As the mandrel here, a universal type having a long mandrel piece and easily providing a concave portion is suitable.

According to a thirteenth aspect of the present invention, there is provided a tube expanding apparatus having a spiral groove capable of winding the above-mentioned flexible mandrel, and sending out the mandrel wound around the spiral groove by forward rotation from the mandrel inlet / outlet. A drum main body that winds the mandrel around the spiral groove by reverse rotation, and a mandrel guide provided at a mandrel entrance / exit portion of the drum main body, and a spiral groove forming portion excluding the mandrel entrance / exit portion on the outer peripheral side of the drum main body. A covering outer cylinder is provided, and a winding drum for storing a mandrel also serves as a mandrel sending mechanism.

According to a fifteenth aspect of the present invention, in the tube expanding device in which the winding drum also serves as a mandrel sending mechanism, the outer cylinder is supported so as to be rotatable with the drum body.

As the mandrel here, a rosary that can bend in all directions around it is suitable.

According to a seventeenth aspect of the present invention, in the tube expanding device in which the winding drum also serves as a mandrel sending mechanism, the drum main body has an end of a mandrel piece group including a large number of mandrel pieces in the mandrel wound around a spiral groove. A stopper which engages with the portion, and an elastic body which elastically brings the end of the group of mandrel pieces into elastic contact with the stopper by pulling an end of a wire passing through the mandrel piece.

An expansion device according to an eighteenth aspect of the invention is an expansion device in which the winding drum also serves as a mandrel sending mechanism, comprising a drum body, a slide base for supporting an outer cylinder and a mandrel guide, and the slide base being a base. And a driving mechanism for reciprocatingly moving in the axial direction of the drum body and for moving the slide base forward at a predetermined pitch.

The heat exchanger of the present invention has a tube whose diameter is enlarged by the expanding method of the present invention using a flexible mandrel.

[0035]

The expansion mandrel of the present invention is such that, when a longitudinal propulsion is applied from outside the pipe, the propulsion is transmitted to the expansion head at the distal end. It can be press-fitted and the tube expanded. And since it is a flexible type, it can be wound up and can pass through a curved portion of a curved cooling pipe.

The pipe expanding method and the pipe expanding apparatus of the present invention can process bent L-shaped and U-shaped cross fin coils by using the flexible mandrel. Also,
The mandrel drawn from the cooling pipe can be wound up and stored compactly.

In the pipe expanding apparatus according to the ninth aspect , the pipe expanding unit is intermittently driven and expanded each time the pipe expanding unit is stopped, so that the number of cooling tubes of the cross fin coils fixed to the work table can be reduced by a unit number. Can be expanded.

[0038] In the tube expanding device according to the tenth aspect ,
Out of four mandrels whose delivery paths are arranged at the four vertices of a rhombus, two types of hairpins having different intervals between straight pipe portions can be expanded by using two mandrels, two mandrels, two mandrels, two mandrels, two mandrels, two mandrels. . In addition, 2
Using the book mandrel, hairpins with different arrangement patterns can be expanded.

[0039] In the tube expanding device according to the eleventh aspect ,
One of the sliders that move synchronously in the opposite direction, the hook pin provided on the forward slider is fitted into the recess of the mandrel piece, and the hook pin provided on the retreating slider is removed from the mandrel piece, so that the mandrel is removed. Is always applied with a forward force by one of the sliders to keep moving forward. Further, if the hook pins are not caught on the mandrel piece, the mandrel can be maintained in a stopped state.

In the tube expanding device according to the thirteenth or fourteenth aspect , when the drum body rotates forward, the mandrel wound around the spiral groove is pushed out through the mandrel guide and inserted into the cooling pipe. You. At this time,
The outer cylinder prevents the mandrel wound around the spiral groove from expanding outward, and converts the rotational force of the drum main body into the driving force of the mandrel. The mandrel is wound around the spiral groove again by the reverse rotation of the inner cylinder.

In the pipe expanding device according to the fifteenth aspect ,
When pushing out the mandrel, the mandrel does not slide on the outer cylinder.

In the pipe expanding device according to the seventeenth aspect ,
The pulling and bending of the wires in the mandrel pieces due to the bending and extension of the mandrel are absorbed.

In the tube expanding device according to the eighteenth aspect ,
The cooling pipes of the cross fin coils are expanded by a unit number.

[0044]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 show an example of a pipe expanding mandrel of the present invention.

The mandrel 10 shown here is a universal type constituted by connecting a number of mandrel pieces 11 formed of thin round bars in the axial direction. At one end of the mandrel piece 11, a plate-like projection 11a is provided. The protrusion 11a is adjacent to the mandrel piece 1
1 is fitted into a concave portion 11b provided at the other end. The fitting portion is rotatably connected in both directions by a pin 12 perpendicular to the projection 11a. Therefore, the mandrel 10 can flex freely in a plane perpendicular to the pin 12 and can be wound. In addition, it is possible to pass through the curved portion of the cooling pipe.

At the tip of the mandrel 10, the expanding head 1
3 is attached. The outer diameter of the expansion head 13 is larger than the inner diameter of the cooling pipe of the cross fin coil to be expanded. On the other hand, the outer diameter of the mandrel piece 11 is
It is smaller than the inside diameter of the cooling pipe. In the middle part of the mandrel piece 11, a concave part 11 with which a hook pin described later
c are provided at four locations on the periphery.

The universal type mandrel 10 is inserted all at once or sequentially into the cooling pipe of the cross fin coil, and the expansion pipe 13 at the end thereof is pressed into the cooling pipe to expand the cooling pipe. Stick to the fin.

Here, since the mandrel 10 is flexed freely in a plane perpendicular to the pin 12, winding the mandrel 10 does not require a large removal allowance, and the overall length of the apparatus can be greatly reduced. Further, by applying an axial force to the mandrel 10, the mandrel 10 is directly inserted into the cooling pipe from the wound state. At this time, mandrel 1
0 can also be applied to the cross-fin coil after bending since it passes through the curved portion of the curved cooling pipe.

FIGS. 3 and 4 show an example of the pipe expanding apparatus of the present invention.

The expansion device shown here is a work table 30 for horizontally fixing the cross fin coil 20 before expansion processing.
And a tube expansion unit 40 provided on one end side of the work table 30.

The work table 30 has a horizontal fixed table 31 and a plurality of movable tables 32 arranged thereon. The movable table 32 is guided by the first guide 33 and moves in the width direction of the fixed table 31. Further, the first guide 33 is guided by the second guide 34 and moves in the longitudinal direction of the fixed base 31.
Therefore, the movable base 32 moves in the width direction and the longitudinal direction of the fixed base 31 and is adjusted in position according to the size of the cross fin coil 20, so that the cross fin coil 20
The fin portion can be supported over a wide area by avoiding the tube sheet.

On the fixing table 31, a positioning plate 3 is further provided.
5 and clamp plates 36 and 37 are provided. The positioning plate 35 moves in the longitudinal direction of the fixed base 31, and positions the cross fin coil 20 on the fixed base 31 with reference to one edge thereof. One clamp plate 36 is fixed to one side edge of the fixed base 31. The other clamp plate 37 is opposed to the one clamp plate 36 and moves in the width direction of the fixing base 31 so that the positioned cross fin coil 20 is sandwiched between the clamp plate 36 and fixed. At this time, in the cross fin coil 20, the longitudinal direction of the cooling pipe coincides with the longitudinal direction of the fixed base 31, and the opening of the cooling pipe faces one longitudinal end of the fixed base 31.

At one end in the longitudinal direction of the fixed base 31, a tube expansion unit 40 and a driving mechanism 50 thereof are provided. The drive mechanism 50 includes a guide 51 provided in the width direction of the fixed base 31,
The expansion unit 40 is linearly driven in the width direction of the fixed base 31 by rotating the screw 52 with the motor 53. The tube expansion unit 40 is driven up and down and back and forth by a mechanism (not shown).

The expansion unit 40 uses the four universal type mandrels 10 described above. At the rear of the expansion unit 40, four winding drums 41 for independently winding the mandrel 10 are provided. Drum 4
1 is independently driven by a motor 42. Then, the four mandrels 10 wound on the four drums 41 are
A mandrel sending mechanism 43 attached to the take-up drum 41 feeds one by one or a plurality thereof simultaneously.

FIGS. 5 to 7 show an example of the mandrel delivery mechanism.

The mandrel delivery mechanism 43 shown here
Is a tubular mandrel guide 43a for guiding the universal type mandrel 10, as shown in FIG.
And a pair of sliders 43b, 43b provided along the mandrel guide 43a, and a pair of gears 43c, 43c for driving the sliders 43b, 43b.

The gears 43c, 43c mesh with each other and are synchronously rotated in opposite directions by a common drive source. Gear 4
One ends of the crank arms 43d, 43d are connected to 3c, 43c eccentrically from the centers thereof. The other ends of the crank arms 43d, 43d are connected to the sliders 43b, 4d.
3b. When the gears 43c, 43c rotate in the reverse direction, the sliders 43b, 43b move to the mandrel guide 4
It reciprocates in the reverse direction along 3a. That is, when one slider 43b moves forward, the other slider 43b retreats, and when the other slider 43b moves forward, one slider 43b retreats.

As shown in FIG. 6, the sliders 43b, 43b are provided with hook pins 43e, 43e, respectively. The hook pins 43e, 43e are reciprocally driven in a direction perpendicular to the mandrel guide 43a, and when the sliders 43b, 43b move forward, the mandrel guide 43 is moved.
a, and separates from the mandrel guide 43a when the sliders 43b, 43b retreat. Then, with the hook pins 43e, 43e approaching the mandrel guide 43a, the tips are inserted into the guides from the openings 43f, 43f provided in the mandrel 43a, and the recesses of the mandrel piece 11 of the mandrel 10 in the guide. 1
1c.

Accordingly, when one of the sliders 43b moves forward, the hook pin 43e engages with the mandrel 10, and the mandrel 10 is sent forward, while the other slider 43b is retracted.
Is moved forward, the slider 43b is also
Causes the mandrel 10 to be sent forward.

That is, the reciprocating operation of the sliders 43b, 43b in the reverse direction and the contacting / separating operation of the hook pins 43b, 43b in synchronization with the reciprocating operation are performed.
Is sent forward without a break. The slider 43
The moving strokes of e and 43e are equal to or an integer multiple of the interval between the concave portions 11c in the mandrel 10, and the openings 43f and 43f are slits longer than the moving strokes of the sliders 43b and 43b.

The universal type mandrel 10
Here, four are used. Therefore, the mandrel guide 4
Four 3a are also provided. The four mandrel guides 4
As shown in FIG. 7, 3a is arranged so that the mandrel 10 sent out from the mandrel guide 43a is located at the four vertices of a rhombus. Here, the interval between the left and right mandrels 10, 10 is 25.4 mm, and the upper and lower mandrels 1
The interval between 0 and 10 is 44.0 mm.

Each of the four mandrel guides 43a is combined with a pair of sliders 43b, 43b. The four sets of sliders 43b, 43b are driven synchronously using the gears 43c, 43c as a common power source. In the four sets of the sliders 43b, 43b, the hook pins 43e, 4e provided on the respective sliders 43e, 43e are provided.
If 3e is operated in synchronization with the movement of the sliders 43b, 43b as described above, the four mandrels 10 are sent out in synchronization. In addition, in any of the sliders 43b, 43b, the hook pins 43e, 4
If 3e is fixed in a state released from the mandrel guide 43a, the mandrel 10 corresponding to the sliders 43e, 43e is maintained in a stopped state. Accordingly, four mandrels 10 can be selectively used, and the optional use of the four mandrels 10 enables expansion of cooling pipes of three types and five patterns.

FIG. 8 shows applicable cooling pipe types, and FIG. 9 shows applicable cooling pipe arrangement patterns.

Applicable cooling pipes have a straight pipe section spacing of 25.4.
There are three types: a hairpin with a diameter of 4 mm, a hairpin with a spacing of 44.0 mm between straight pipes, and a straight pipe. For the hairpin, when the plane passing through the center of the straight pipe portion is horizontal (FIG. 9).
A), and the case where the plane passing through the center of the straight pipe portion is inclined in the same direction by 60 ° or 120 ° with respect to the horizontal plane (B in FIG. 9).
C) can be expanded, and the hairpin can be expanded when the plane passing through the center of the straight pipe portion is vertical (E in FIG. 9).

Because the distance between the left and right mandrels 10 and 10 is 25.4 mm, the two mandrels 10 and 10 are separated.
By using 10, expansion can be performed on the pattern of FIG. 9A. In addition, since the intervals between the upper and right, upper and left, lower and right, lower and left mandrels 10 and 10 are also 25.4 mm, by using the upper and right or lower and left mandrels 10 and 10, 9B can be performed on the pattern of FIG. 9B, and can be performed on the pattern of FIG. 9C by using the upper and left or lower and right mandrels 10, 10. 9E can be expanded by using the upper and lower mandrels 10, and can be expanded by using one of the mandrels 10 for a straight pipe.

FIGS. 10 and 11 show structural examples of a flare processing machine and a pipe end clamp provided in the pipe expanding unit.

As described above, the tube expansion unit 40 reciprocates right and left along one end of the fixed base 31 along the end line. A flare processing machine 60 is attached to one side (front side) of the expansion unit 40. Flare processing machine 6
No. 0 has a sleeve 61 divided in the circumferential direction as shown in FIG. The inner surface of the sleeve 61 is a tapered surface that expands toward the rear end, and the head 62 is inserted into the inside from the rear. The outer surface of the head 62 is a tapered surface corresponding to the inner surface of the sleeve 61. Therefore, by inserting the head 62 into the inside of the sleeve 61 from behind, the sleeve 61 expands in diameter.

The flare processing machine 60 has two sets of such sleeves, and before expanding the cross-fin coils fixed on the fixed base 31, two sets of sleeves are sequentially placed in the pipe from the opening of the cooling pipe. And the tube end is subjected to secondary flaring and tertiary flaring. Fig. 1 shows the end of the cooling pipe after the secondary flaring and the tertiary flaring.
1, reference numeral 21 denotes a cooling pipe, 21a denotes a secondary flared portion, and 21b denotes a tertiary flared portion.

In front of the four mandrel guides 43a in the pipe expanding unit 40, pipe end chucks 44 are provided, respectively. As shown in FIG. 11, each pipe end chuck 44 has a pair of upper and lower claws 44a, 44a obtained by dividing a cylindrical body by a plane passing through the center. Tapered portions 44b, 44b gradually increasing in diameter toward the distal end are provided on the outer surfaces of the intermediate portions of the claws 44a, 44a. Claws 44a, 44
A ring 44c is externally fitted to a. The ring 44c closes the claws 44a, 44a by advancing in the axial direction outside the tapered portions 44b, 44b, thereby chucking the pipe end of the cooling pipe 21 after the secondary flare and the tertiary flare have been completed. The protrusions 44d, 44d are formed on the inner surfaces of the tips of the claws 44a, 44a in order to prevent the chucked tube ends from coming off.
Is provided. Then, the pipe expansion unit 40 performs pipe expansion processing (primary flare processing) on the cooling pipe in a state where the pipe end is chucked by the pipe end chuck.

Next, the expansion procedure will be described.

The positions of the movable table 32 and the positioning plate 35 of the work table 30 are adjusted according to the size of the cross fin coil to be expanded. Cross fin coil 20
The cross fin coil 20 is mounted on the movable base 32 with the opening of the cooling pipe facing the expansion unit 40, and is fixed by the clamp plates 36 and 37.

The expansion unit 40 is guided to the initial position where the flare processing machine 60 faces the pipe end of the first cooling pipe in the cross fin coil 20. The flare processing machine 60 performs secondary flaring and tertiary flaring on the end of the first cooling pipe.

The pipe expanding unit 40 is located on the side (front of the forward path).
And the flare processing machine 60 is caused to face the pipe end of the second cooling pipe. The flare machine 60 performs secondary flaring and tertiary flaring on the end of the second cooling pipe.

If the center of the first cooling pipe after the pipe end processing is continued and the center of the mandrel guide 43a in the expansion unit 40 coincides with the pipe end processing of the cooling pipe, the pipe end chuck provided in front of the mandrel guide 43a. At 44, the pipe end of the first cooling pipe is chucked. The positional relationship between the expansion unit 40 and the flare processing machine 60 is adjusted so that the expansion unit 40 stops at a position where the center of the cooling pipe coincides with the center of the mandrel guide 43a.

With the pipe end of the first cooling pipe chucked, the gears 43 c, 43 c rotate, and the reciprocal movement of the sliders 43 b, 43 b due to the rotation and the engagement of the hook pins 43 e, 43 e synchronized with the operation. By the separating operation, the universal type mandrel 10 is sent forward from the winding drum 41 and inserted into the cooling pipe. Thereby, the pipe expansion head 13 attached to the tip of the mandrel 10 is pressed into the cooling pipe, and the cooling pipe is expanded and fixed to the fin. At this time, the cooling pipe located in front of the flare processing machine 60 is subjected to pipe end processing by the flare processing machine 60.

When the expansion of the cooling pipe is completed, the winding drum 41 is driven by the motor 42 in a direction in which the mandrel 10 is wound, and the mandrel 10 is pulled out from the cooling pipe and wound on the winding drum 41. As described above, five types of pipe expansion are possible by selecting and using four mandrels 10 according to the shape and arrangement pattern of the cooling pipes.

Thereafter, every time the pipe expansion unit 40 is driven by one pitch, the flare processing and the pipe expansion of the cooling pipe are simultaneously performed in parallel. When the cooling tube flaring is over,
Pipe expansion is performed on the remaining cooling pipes, and all pipe expansion processing for the cross fin coil is completed.

The universal type mandrel 1
In the above embodiment, the delivery of 0 is performed by a pair of crank mechanisms. However, the present invention is not limited to this. For example, a male screw is formed on the outer surface of the universal type mandrel 10 and a nut member screwed to the male screw is rotated. Can also be sent out.

The number of universal type mandrels 10 used by the mandrel delivery mechanism 43 is four in the above embodiment, but the number is not limited, and for example, one mandrel is inserted one by one into the cooling pipe of the cross fin coil. Alternatively, a mandrel can be simultaneously inserted into all the cooling pipes.

When the four mandrels 10 are arranged at the respective vertices of the diamond, it is possible to cope with more types of cooling pipes by mechanically adjusting the mandrel interval between the upper and lower mandrels and the left and right mandrels. it can.

FIG. 12 shows another example of the tube expanding mandrel of the present invention.

The mandrel 10 shown here is of a rosary type in which a large number of mandrel pieces 11, 11,... Made of steel balls are connected in a row. Each mandrel piece 11 has a radial through hole 11d passing through the center thereof.
d are connected in a line by a flexible wire 14 passing therethrough. A spherical pipe expansion head 13 is connected to the distal end side of the leading mandrel piece 11, and a spacer 15 is provided between the adjacent mandrel pieces 11.

The expansion head 13 has a diameter larger than the inner diameter of the cooling pipe of the cross-fin coil to be expanded, and is connected to the tip of the wire 14. Incidentally, the diameter of the mandrel piece 11 is set smaller than the inner diameter of the cooling pipe. The spacer 15 is a thick-walled disc having a smaller diameter than the mandrel piece 11, and has a through hole 15a at the center thereof through which the wire 14 passes. Spacing 15
Are formed as spherical seats 15b, 15b in surface contact with the mandrel pieces 11, 11 on both sides.

The rosary-type mandrel 10 has not only flexibility but also an arc when curved.
It is smoother than the universal type mandrel described above. Further, a small radius of curvature can be easily obtained.
Therefore, it is particularly suitable for expanding the L-shaped and U-shaped cross fin coils.

The spacer 15 interposed between the adjacent mandrel pieces 11, 11 suppresses local wear of the mandrel pieces 11, 11,.... Instead of using spacer 15
As shown in FIG. 3, the spherical seat 11 is attached to the mandrel piece 11.
e may be provided.

FIGS. 14 to 21 show other examples of the pipe expanding apparatus of the present invention.

The tube expanding device shown here expands the L-shaped and U-shaped cross-fin coils 20 using the rosary-shaped mandrel 10 described above. As shown in FIGS. 14 to 16, the basic structure includes a work table 30 for supporting and fixing the cross fin coil 20, and a tube expansion unit 40 provided at one end of the work table 30.

The work table 30 moves the cross fin coil 20 in the horizontal direction by a large number of balls 38 arranged on the surface of the horizontal fixed table 31, and the cross fin coil 20 is moved by the positioning plate 35 provided at one end. Is positioned at the processing position.

The cross fin coil 20 is L-shaped or U-shaped as described above. The open end of the cooling pipe (hairpin) is bent at a right angle in the L shape, and both ends are bent at the right angle in the U shape. Each of the cross fin coils 20 is positioned on the work table 30 with the open end of the cooling pipe (hairpin) facing one end of the work table 30, and the end is attached to a lifting table 73 described below. A pair of chucks 79, 7
9, and the opposite end is fixed by a fixing mechanism 39 provided on the other end of the work table 30.

The fixing mechanism 39 has a movable frame 39b which is guided by a guide 39a and moves in the longitudinal direction of the work table 30. A fixing plate 3 for pressing and fixing the other end of the L-shaped cross fin coil 20 is provided on the front surface of the lower end portion of the movable gantry 39b.
9c is attached. Above the fixing plate 39c,
An elevating beam 39d that moves up and down along the movable gantry 39b is provided. A pair of chucks 39e, 39e are attached to the lower surface of the lifting beam 39d. Chuck 3
Numerals 9e and 39e chuck the other end of the U-shaped cross fin coil 20, the height of which is adjusted by elevating and lowering the elevating beam 39d.
The distance is adjusted by traversing along the lower surface of the.

The tube expansion unit 40 provided at one end of the work table 30 is driven by a driving mechanism 70 on three axes. The driving mechanism 70 includes a fixed base 71 and a base 7 that can be moved up and down by being guided by vertical guides 72a, 72a attached to the front surface thereof.
And 3. The base 73 is driven by a motor 74a mounted on the fixed base 71 to form a pair of vertical screws 75a,
75a is moved up and down by being rotationally driven.

As shown in FIGS. 17 and 18, slide bases 76a and 76b are provided on the base 73 in two stages. The lower slide base 76a is driven by a motor 74b attached to the end of the base 73 to rotate a horizontal screw 75b, thereby rotating the horizontal guide 7a.
It is guided (2b, 72b) and moves (traverses) on the base 73 in the longitudinal direction (width direction of the work table 30). Also,
The upper slide base 76b is connected to the cylinders 74 on both sides.
By the guides c and 74c, they are guided by the horizontal guides 72c and 72c to move back and forth on the lower slide base 76a. The pipe expansion unit 40 is installed on the upper slide base 76b, and the pipe expansion unit 40 is driven in three axes by moving up and down the base 73 and moving the slide bases 76a and 76b forward and backward.

[0094] The tube expansion unit 40 has a winding drum 41 which also serves as a mandrel sending mechanism. The winding drum 41
As shown in FIG. 19, a drum main body 41a and an outer cylinder 41b are concentrically combined. Drum body 41a
Is movably supported in the axial direction by a horizontal spline shaft 41c. The spline shaft 41c is provided with bearings 4 at both ends.
1d, 41d rotatably supported by the winding drum 4
1 rotates on pulleys 42a, 4
The rotation is driven by the transmission via the belt 2a and the belt 42b. Then, the drum main body 41a rotates in synchronization with this rotation.

On the outer peripheral surface of the drum main body 41a, two spiral grooves 41 into which the rosary-shaped mandrel 10 described above are fitted.
e and 41e are provided in parallel. Spiral grooves 41e, 4
According to 1e, the two mandrels 10, 10 are spirally positioned and wound on the outer peripheral surface of the drum main body 41a from one end to the other end and housed. A stopper 41f for locking the last mandrel piece 11 of the mandrel 10 is provided at one end of the spiral groove 41e.

As shown in FIG. 20, the rear end of the wire 14 is drawn into the drum main body 41a via the guide roller 41g, and is held by the holder 41j fixed to the drum main body 41a.
Has been passed through. An elastic body 41h is provided between the holder 41j and the stopper 41i attached to the tip of the wire 14.
Is interposed. The elastic body 41h is formed of a compression spring, and causes the rearmost mandrel piece 11 to elastically contact the stopper 41 by pulling the wire 14 toward the rear end. On the other hand, the distal end of the mandrel 10 is drawn downward from the other end of the spiral groove 41e through a vertical tubular double-mandrel guide 45. The mandrel guide 45 is of a fixed type fixed on the slide base 76b.

The outer cylinder 41b holds the mandrels 10, 10 spirally wound around the outer peripheral surface of the drum main body 41a from the outside. The outer cylinder 41b is provided with a gap for accommodating the mandrels 10, 10 outside the drum main body 41a. Placed in
It is rotatably supported by bearings 41j, 41j at both ends. A lead portion 41k is provided on the other end side (mandrel pull-out side) of the outer cylinder 41b. Lead part 41k
Is made of a rotatable steel ball and is fitted over the other end of the spiral groove 41e above the other end of the drum main body 41a.

Thus, when the drum body 41a rotates, the spiral groove 41e is led by the lead portion 41k, so that the drum body 41a moves in the axial direction along the spline shaft 41c while rotating. This spiral movement is caused by the mandrels 10, 1 spirally wound around the drum main body 41a.
The pitch is equal to 0. Then, by rotating the drum main body 41a in a direction in which the drum main body 41a moves to the other end side (mandrel pull-out side), the two mandrels 10, 10 wound around the drum main body 41a become stoppers 41f.
And is pushed downward from the fixed double mandrel guide 45.

Below the fixed double mandrel guide 45, a double tube end chuck 44 is vertically provided via a telescopic mandrel guide 46 as shown in FIG. The tube end chuck 44 is provided with a support plate 47 that can be moved up and down.
Attached to the lower surface of the cylinder 48 (FIGS. 17 and 1).
8). The structure of the pipe end chuck 44 is the same as that of the tube end chuck (FIG.
Basically the same as 1), the pair of claws 44a, 44a opened by the spring 44e are closed by the lowering of the ring 44c, and the pipe end of the cooling pipe 21 which has finished the flaring is chucked.

In order to flare the pipe end of the cooling pipe 21 in advance, a double flare processing machine 60 is provided beside the pipe end chuck 44 (FIG. 18). The structure of the flare processing machine 60 is basically the same as that of the flare processing machine (FIG. 10) provided in the above-described tube expanding apparatus.

Next, the expansion procedure will be described.

The cross fin coil 20 to be expanded is fixed on the work table 30, the expansion unit 40 is moved, and the flaring machine 60 flares the pipe ends of the cooling pipes 21 from two ends. The basic operation of expanding the cooling pipes 21 whose pipe end portions have been flared by the expansion unit 40 two by two is basically the same as that of the above-described expansion apparatus. The difference is that mandrel 10,10
, Which will be described below.

The two cooling pipes 21 and 21 have two
When the continuous pipe end chuck 44 is positioned, the pipe end chuck 4
4 is lowered, and the tube end is fixed by the tube end chuck 44. At this time, the two mandrels 10, 10 are in a state of being wound around the drum main body 41a.

When the tube ends of the two cooling tubes 21 and 21 are fixed by the tube end chuck 44, the motor 42 operates, and
The spline shaft 41c rotates. Thereby, the drum main body 41a moves in the axial direction while rotating. The moving direction of the drum main body 41a is on the other end side (mandrel pull-out side). As a result, the two mandrels 10, 10 spirally wound around the outer peripheral surface of the drum main body 41a are pushed by the stopper 41f, and are sequentially pushed downward from the other end side of the drum main body 41a. At this time, the outer cylinder 41b
Are two mandrels 1 wound around the drum main body 41a.
0, 10 are prevented from bulging outward, and the propulsive force applied to the last mandrel piece 11 is applied to the distal end of the expansion head 13.
Without loss. Further, the mandrels 10, 10 are pressed against the inner peripheral surface of the outer cylinder 41b, but the outer cylinder 41b rotates together with the abrasion thereof, so that they do not rub against the inner peripheral surface of the outer cylinder 41b.

The two mandrels 10, 10 pushed downward from between the drum body 41a and the outer cylinder 41b are composed of a fixed double mandrel guide 45, a telescopic double mandrel guide 46, and a double tube. It is pushed into the cooling pipes 21 and 21 at a stretch through the end chuck 44. Thus, the cooling pipes 21 are expanded simultaneously and in a short time, and the fins are fixed thereto.

Since the two mandrels 10 and 10 are rosary-type and have a small radius of curvature and a smooth curve,
The curved portions of the cooling pipes 21 and 21 also pass smoothly. Therefore, the expansion process can be performed without any problem whether the cross fin coil 20 is L-shaped or U-shaped. When the mandrel 10 bends or stretches, its length changes,
The wire 14 in the mandrel 10 is pulled or bent, and this pull or bending is absorbed by the elastic body 41h in the drum main body 41a. The elastic body 41h is a compression spring here, but the same effect can be obtained by connecting the end of the wire 14 to the drum main body 41a via an extension spring.

The mandrels 10, 10 are provided with cooling pipes 21, 21.
, The motor 42 performs the reverse rotation operation. As a result, the drum main body 41a returns to the original position while rotating in the reverse direction, and the two mandrels 10, 10 are wound up again and stored in the drum main body 41a. Then, in order to expand the next two cooling pipes 21 and 21, the pipe end chuck 44 is opened and raised, and then the expansion unit 40 is expanded.
Moves.

In this embodiment, the expansion unit 40 uses two mandrels 10, but it is also possible to operate four mandrels 10 simultaneously, similarly to the above-described expansion device. However, the number is not limited.

[0109]

As described above, since the pipe expanding mandrel of the present invention is of a flexible type, it can be wound up, thereby shortening the apparatus length. In addition, since it can pass through the bent portion of the bent cooling pipe, the cross-fin coil that has been bent can also be expanded.

In particular, a rosary-shaped mandrel can be easily curved with a small curve and a small radius of curvature. Therefore, it is particularly suitable for the tube expanding process of the cross-fin coil that has been bent.

In a rosary type mandrel, when a spacer is interposed between adjacent mandrel pieces, local wear of the mandrel pieces can be suppressed.

Since the pipe expanding method and the pipe expanding apparatus of the present invention are of a mechanical type using a mandrel, uniform pipe expanding can be performed without being affected by work hardening of the cooling pipe, etc. Can be handled without any problems. In addition, although the mandrel is flexible, the mandrel is flexible, so that the entire length of the device can be greatly reduced by winding the mandrel, and the present invention is applied to a cross-fin coil after bending. be able to.

Since the pipe expanding device according to the ninth aspect includes the pipe expanding unit that moves in the pipe row direction of the cross fin coils to be expanded, the cooling pipes of the cross fin coils can be expanded by a unit number. The unit can be downsized.

The pipe expansion device according to the tenth aspect can cope with a plurality of types and a plurality of arrangement patterns of cooling pipes by selecting and using four universal mandrels in which discharge paths are arranged at four apexes of a rhombus. In addition, it is possible to reduce the equipment cost and the number of steps required for the setup change.

According to the eleventh aspect of the present invention, the wound mandrel can be sent out by a simple mechanism without interruption by the synchronous operation of the pair of sliders and the hook pins provided on each slider. It can easily handle the selection and use of a mandrel.

In the tube expanding device according to the thirteenth or fourteenth aspect , the winding drum for accommodating the mandrel also serves as the mandrel sending mechanism, and thus has a simple structure. Also, the mandrel can be sent and stored in a short time,
High work efficiency.

In the pipe expanding device according to the fifteenth aspect , the mandrel does not slide on the outer cylinder when the mandrel is pushed out.
Mandrel wear can be prevented. Further, the rotation of the drum main body is not hindered, and the driving force can be reduced.

The pipe expanding device according to claim 17 facilitates bending of the mandrel, and facilitates winding and insertion of the mandrel into a curved cooling pipe.

In the tube expanding device according to the eighteenth aspect , since the cooling process of the cooling tubes of the cross fin coils can be performed by a unit number, the device can be further miniaturized.

The heat exchanger of the present invention is manufactured by mechanical expansion after bending the pipe even when the pipe is curved, so that the adhesion between the pipe and the fin is good and the fin is less likely to fall. Therefore, high performance is obtained. In addition, since it is manufactured by a small and economical device, the manufacturing cost is reduced.

[Brief description of the drawings]

FIG. 1 is a side view showing an example of a pipe expanding mandrel of the present invention.

FIG. 2 is a plan view and a side view of a mandrel piece constituting the mandrel.

FIG. 3 is a plan view showing an overall configuration of an example of the pipe expanding apparatus of the present invention.

FIG. 4 is a side view of the pipe expanding device.

FIG. 5 is a plan view showing a slider drive unit of the mandrel sending mechanism.

FIG. 6 is a cross-sectional plan view showing a hook pin.

FIG. 7 is a front view showing a mandrel arrangement.

FIG. 8 is an explanatory diagram of an applicable cooling pipe.

FIG. 9 is an explanatory diagram of an applicable cooling pipe arrangement pattern.

FIG. 10 is a schematic diagram illustrating a configuration of a flare processing machine.

FIG. 11 is a schematic view showing a configuration of a pipe end chuck.

FIG. 12 is a side view showing another example of the pipe expanding mandrel of the present invention.

FIG. 13 is a side view showing still another example of the pipe expanding mandrel of the present invention.

FIG. 14 is a plan view showing another example of the pipe expanding device of the present invention.

FIG. 15 is a side view of the pipe expanding device.

FIG. 16 is a front view of the pipe expanding apparatus.

FIG. 17 is an enlarged side view showing a part of the tube expansion unit.

FIG. 18 is an enlarged front view showing a part of a pipe expansion unit.

FIG. 19 is a front view showing the structure of the drum.

FIG. 20 is a view taken along the line AA of FIG. 19;

FIG. 21 is a view taken along the line BB of FIG. 19;

FIG. 22 is a plan view of a conventional pipe expanding device.

FIG. 23 is a side view of a conventional pipe expanding device.

FIG. 24 is a perspective view of a cross fin coil.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Mandrel 11 Mandrel piece 13 Expansion head 14 Wire 15 Spacer 20 Cross fin coil 21 Cooling tube 30 Work table 40 Expansion unit 41 Drum 41a Drum main body 41b Outer cylinder 41f Stopper 41h Elastic body 42 Motor 43 Mandrel sending mechanism 44 Pipe end chuck 45 Mandrel guide 60 Flare processing machine 70 Drive mechanism

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Noriaki Nakao 1304 Kanaokacho, Sakai City, Osaka Daikin Industries, Ltd.Sakai Factory Kanaoka Factory (72) Inventor Takuo Katakami 1304, Kanaokacho, Sakai City, Osaka Daikin Industries Sakai Factory Co., Ltd. Kanaoka Factory (56) References Japanese Patent Publication No. 51-23466 (JP, B2) Japanese Utility Model Publication No. 56-24577 (JP, Y2) (58) Field surveyed (Int. Cl. ⁷ , DB name) B21D 39/20 B21D 53/08

Claims (19)

(57) [Claims] 1. A number of tools which can be inserted into a pipe to be expanded.
The drel piece (11,11 ...) is bent at the joint.
Connected in a row so that the tube expansion head (13)
And a number of mandrel pieces (1
1,11 ...) as a short rod-like body, the mandrel tube expansion of the variable you characterized in that connecting the adjacent mandrel pieces (11, 11) foldable in Shiwashiki. 2. A number of tools which can be inserted into a pipe to be expanded.
The drel piece (11,11 ...) is bent at the joint.
Connected in a row so that the tube expansion head (13)
And a number of mandrel pieces (1
1, 11...) Are formed into spherical bodies, and the spherical bodies are provided with radial through holes (11d), and a larger number of mandrel pieces (11, 11) than the wires (14) passed through the through holes (11d).
Mandrel pipe expansion of the variable Shiwashiki you, characterized in that the concatenation of the ...) in a row. 3. A through hole (15a) through which a wire (14) passes.
With mandrel pieces (11, 1
1) The spacer (15) forming the spherical seat (15b, 15b) in surface contact with the mandrel piece (11,
11. The mandrel for expanding a pipe according to claim 2 , wherein the mandrel is provided between the pipes. 4. A method for expanding a pipe, characterized in that a propulsive force is applied to the mandrel (10) according to any one of claims 1 to 3 from outside the pipe to press-fit a pipe expansion head (13) at a distal end into the pipe. 5. A mandrel (10) is wound on a winding drum (4).
The method for expanding a pipe according to claim 4 , wherein the pipe is wound up and stored in (1). 6. A multiplicity of machines which can be inserted into a pipe to be expanded.
The drel piece (11,11 ...) is bent at the joint.
Connected in a row so that the tube expansion head (13)
From outside the tube to the flexible mandrel (10)
Applying force to press-fit the expansion head (13) at the tip into the pipe
And the mandrel (10) to the winding drum (41)
A tube expansion method characterized by winding and storing. 7. A take-up drum for accommodating winding the mandrel (10) according to claim 1 (41)
And applying longitudinal propulsion to the mandrel (10),
A pipe expanding device comprising a mandrel delivery mechanism (43) for press-fitting a pipe expanding head (13) at a tip of a mandrel (10) into a pipe. 8. A multiplicity of machines that can be inserted into a pipe to be expanded.
The drel piece (11,11 ...) is bent at the joint.
Connected in a row so that the tube expansion head (13)
Wind up the flexible mandrel (10) with the
For storing winding drum (41) and mandrel (10)
Applying a longitudinal propulsion force, the tip of the mandrel (10)
Of mandrel for press-fitting tube expansion head (13) into tube
A tube expansion device comprising a mechanism (43). 9. The expansion device according to claim 7, wherein a work table (30) for fixing a cross fin coil (20) to be expanded is provided, and a winding drum (41) and a mandrel sending mechanism (43). A pipe expanding apparatus characterized in that a pipe expanding unit (40) equipped with the above (1) is movably provided in a pipe arrangement direction of a cross fin coil (20) fixed to a work table (30). 10. The expansion device according to claim 9 , wherein
An expansion device characterized in that the expansion unit (40) uses four mandrels (10) and the delivery paths of the four mandrels (10) are arranged at the four vertices of a diamond. 11. The expansion device according to claim 7 , wherein a mandrel sending mechanism (43) is attached to the winding drum (41), and the mandrel sending mechanism (4).
3) a mandrel guide (43a) for linearly guiding the mandrel (10), and a pair of sliders (43b, 43b) synchronously reciprocating in the opposite direction along the mandrel guide (43a) by a pair of crank mechanisms. The slider (43b, 43b) is equipped with a concave portion (11) provided in each mandrel piece (11) of the mandrel (10) in the mandrel guide (43a) by moving in a direction perpendicular to the mandrel guide (43a). 11c) The expansion device having a movable hook pin (43e, 43e) fitted into the expansion device. 12. The expansion device according to claim 11 , wherein the mandrel (10) is the expansion mandrel according to claim 1. Description: 13. A pipe expanding apparatus for expanding a pipe by the mandrel (10) according to claim 1 , comprising a spiral groove (41e) capable of winding the mandrel (10), and rotating in a forward direction. A drum body (41a) for feeding a mandrel (10) wound around the spiral groove (41e) from the mandrel access port, and winding the mandrel (10) around the spiral groove (41e) by reverse rotation; and the drum body (41a). And a mandrel guide (45) provided at the mandrel entrance / exit portion, and an outer cylinder (41b) that covers a spiral groove forming portion excluding the mandrel entrance / exit portion on the outer peripheral side of the drum main body (41a).
A pipe expansion device, comprising: 14. A multiplicity of tubes that can be inserted into a tube to be expanded.
Bend the mandrel pieces (11, 11 ...) at the joints
The pipes are connected in a row so that the tube expansion head (1
Expanded by flexible mandrel (10) with 3) attached.
A pipe expanding device for winding a mandrel (10).
Helical groove (41e), and the helical groove
Mandrel (10) to be wound around (41e)
The mandrel (10) is sent out of the entrance and reverse rotation.
A drum body (41a) wound around a spiral groove (41e);
A mask provided at the mandrel entrance / exit portion of the drum body (41a)
And a drum guide (45).
A spiral groove excluding the mandrel access port on the outer peripheral side of 1a)
An outer cylinder (41b) for covering the formation site is provided.
Expansion device. 15. The outer cylinder (41b) is connected to the drum body (41).
The tube expansion device according to claim 13 or 14 , wherein the tube expansion device is supported so as to be rotatable with a). 16. Mandrel (10) according to claim 2 or
3 of claim 13 to 15 is good for expansion mandrel according to
The pipe expansion device according to any one of the above. 17. Mandrel (10) according to claim 2 or
3. The expansion mandrel according to claim 3 , wherein the drum body (4
1a) a stopper (41f) for engaging an end of a mandrel piece group consisting of a large number of mandrel pieces (11) in the mandrel (10) wound around the spiral groove (41e); and the mandrel piece (11). claim comprising an elastic member for elastic contact to an end of the mandrel piece group in said stopper (41f) (41h) by pulling the ends of the insertion wire (14) 13-15
The pipe expansion device according to any one of the above. 18. A drum body (41a) and an outer cylinder (41).
b) and a slide base (76a, 76b) for supporting the mandrel guide (45), and the slide base (76a, 76b) is provided with respect to the base (73) in the axial direction of the drum body (41a). thereby reciprocally movably supporting the slide base (76a, 76 b) according to claim 1 having a drive mechanism for the to a predetermined pitch each forward (70)
The pipe expansion device according to any one of 3 to 17 , 19. The tube expansion method according to any one of claims 4-6, the heat exchanger comprising the tube diameter is enlarged.