JP2006242426A - Pipe expander - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pipe expander capable of adjusting a fin pitch in a desired state in pipe expanding processing. <P>SOLUTION: This pipe expander is a pipe expander for fixing fins 23 and heat transfer tubes 24 by expanding the heat transfer tubes 24 inserted into holes of the fins 23, in a heat exchanger 2 having a plurality of fins 23 laminated by arranging a plurality of holes and a plurality of heat transfer tubes 24 penetrating through the fins 23 by being inserted into the holes; and has a plurality of mandrels 4 and a longitudinal presser plate 8. The plurality of mandrels 4 are inserted into the plurality of heat transfer tubes 24, and expand the heat transfer tubes 24. The fore-and-aft presser plates 8 hold both end parts of the plurality of fins 23. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a tube expansion device.

In manufacture of a heat exchanger, a heat exchanger tube is passed through the fins laminated with a predetermined fin pitch. Then, a mandrel is inserted into the heat transfer tube penetrating the fins, thereby expanding the diameter of the heat transfer tube and fixing the heat transfer tube and the fin (see Patent Document 1).
JP-A-6-65415

  When the above tube expansion process is started, the heat transfer tube in which the mandrel is inserted is expanded in the outer diameter direction. That is, when the mandrel is inserted from one end of the heat transfer tube, a difference occurs between the tube diameter of the portion where the mandrel has already passed and the tube diameter of the portion where the mandrel has not yet passed. And the fin located in the outer side of a heat exchanger tube is pressed to the direction in which the spreading deformation of the heat exchanger tube has not yet arisen, ie, the other end side of a heat exchanger tube. For this reason, the fin pitch of the fin located in the other end side of a heat exchanger tube is small, the fin density of the other end side becomes larger than the fin density of the one end side, and there exists a possibility that a deviation may arise in a fin pitch. As described above, in the conventional pipe expanding device, it is difficult to make the distribution of the fin pitch into a desired mode due to the influence of the deformation of the fin during the pipe expansion.

  The subject of this invention is providing the pipe expansion apparatus which can adjust a fin pitch to a desired state in a pipe expansion process.

  A tube expansion device according to a first aspect of the present invention is a heat exchanger comprising a plurality of stacked fins provided with a plurality of holes and a plurality of heat transfer tubes inserted into the holes and penetrating the fins, and inserted into the fin holes. A tube expansion device that expands a heat transfer tube to fix a fin and a heat transfer tube, and includes a plurality of mandrels and a holding member. The plurality of mandrels are inserted into the plurality of heat transfer tubes to expand the heat transfer tubes. The holding member holds both end portions of the plurality of fins.

  In this pipe expansion device, since both ends of the plurality of fins are held by the holding member, the movement of the plurality of fins in the pipe expansion process is restricted by the holding member. For this reason, it is possible to perform the pipe expansion process while suppressing the fin pitch from changing from the state set before the pipe expansion process. Thereby, in this pipe expansion apparatus, a fin pitch can be adjusted to a desired state in a pipe expansion process.

The tube expansion device according to the second aspect of the present invention is the tube expansion device of the first aspect, wherein the holding member has a contact surface that contacts both end portions of the plurality of fins.
In this tube expansion device, the contact surface of the holding member and the both ends of the plurality of fins are in contact with each other. For this reason, a frictional force is generated between the contact surface and the fin, and the movement of the fin in the tube expansion process is regulated by the frictional force. Thereby, in this pipe expansion apparatus, a fin pitch can be adjusted to a desired state in a pipe expansion process.

A tube expansion device according to a third aspect of the present invention is the tube expansion device of the second aspect, wherein the fin has a rectangular shape having two long ends and two short ends, and the contact surface is a long end. Touch the part.
In this pipe expansion device, the contact surface of the holding member and the long end portions of the plurality of fins are in contact with each other. For this reason, a contact surface contacts the comparatively large area of a fin, and the force which controls a motion of a fin also becomes comparatively large. Thereby, in this pipe expansion apparatus, a fin pitch can be adjusted to a desired state in a pipe expansion process.

A tube expansion device according to a fourth aspect of the present invention is the tube expansion device of the second or third aspect, wherein the contact surface covers the whole of the plurality of stacked fins when viewed from a direction perpendicular to the contact surface. Have a size.
In this tube expansion device, the contact surface has a size that covers the entire plurality of stacked fins in a projected view as viewed from a direction perpendicular to the contact surface, and therefore can contact the entire plurality of fins. Thereby, in this pipe expansion apparatus, the fluctuation | variation of a fin pitch can be suppressed in the whole laminated | stacked fin.

A tube expansion device according to a fifth aspect of the present invention is the tube expansion device according to any one of the second to fourth aspects, wherein the contact surface is formed of a flexible foam material.
In this tube expansion device, the contact surface formed of a flexible foam material and both end portions of the fin come into contact with each other. For this reason, a frictional force arises between a contact surface and a fin, and the movement of the fin in a pipe expansion process can be controlled. Further, since the contact surface is formed of a flexible material, the risk of the fins being broken can be reduced.

The tube expansion device according to a sixth aspect of the present invention is the tube expansion device of the second to fourth aspects, wherein the contact surface is made of a metal material, and fine irregularities are provided on the surface.
In this pipe expansion device, the contact surface provided with fine irregularities on the surface comes into contact with both end portions of the fin. For this reason, a frictional force arises between a contact surface and a fin, and the movement of the fin in a pipe expansion process can be controlled. Moreover, since the contact surface is made of metal, the durability of the holding member can be improved.

A tube expansion device according to a seventh aspect of the present invention is the tube expansion device according to any one of the second to fourth aspects, wherein the contact surface is made of an elastic material.
In this tube expansion device, the contact surface made of an elastic material and the fin come into contact with each other. For this reason, the fin is easily caught on the contact surface, and the movement of the fin in the tube expansion process can be regulated by the frictional force. Thereby, the fin pitch can be adjusted to a desired state in the pipe expansion process.

A tube expansion device according to an eighth invention is the tube expansion device according to any one of the first to seventh inventions, wherein the holding member includes a first holding member that holds one end of the plurality of fins and the other end of the plurality of fins. And a second holding member for holding.
In this tube expansion device, the fin can be sandwiched from both sides by the first holding member and the second holding member. For this reason, the movement of the fin in a pipe expansion process can be controlled more strongly. Thereby, in this pipe expansion apparatus, the fluctuation | variation of the fin pitch in a pipe expansion process can be suppressed more.

A tube expansion device according to a ninth aspect of the present invention is the tube expansion device of the eighth aspect, wherein the first holding member and the second holding member are urged in a direction in which the fin is sandwiched.
In this pipe expansion device, the first holding member and the second holding member are urged in the direction in which the fin is sandwiched. For this reason, the friction force which acts on a fin and a friction surface becomes stronger. Thereby, in this pipe expansion apparatus, the fluctuation | variation of the fin pitch in a pipe expansion process can be suppressed more.

In the pipe expansion device according to the first invention, the pipe expansion process can be performed while suppressing the fin pitch from changing from the state set before the pipe expansion process, and the fin pitch can be adjusted to a desired state in the pipe expansion process. .
In the tube expansion device according to the second aspect of the present invention, the movement of the fin in the tube expansion process is restricted by the frictional force between the contact surface and the fin, and the fin pitch can be adjusted to a desired state in the tube expansion process.

In the tube expansion device according to the third aspect of the present invention, the contact surface is in contact with a relatively large area of the fin, and the force that restricts the movement of the fin is also relatively large. Therefore, the fin pitch can be adjusted to a desired state in the tube expansion process. .
In the tube expansion device according to the fourth aspect of the invention, it is possible to make contact with the whole of the plurality of fins, and to suppress fluctuations in the fin pitch in the whole laminated fins.

In the tube expansion device according to the fifth aspect of the present invention, it is possible to restrict the movement of the fin in the tube expansion process. Further, since the contact surface is formed of a flexible material, the risk of the fins being broken can be reduced.
In the pipe expansion device according to the sixth aspect of the invention, the movement of the fins in the pipe expansion process can be restricted. Moreover, since the contact surface is made of metal, the durability of the holding member can be improved.

In the pipe expansion device according to the seventh aspect of the invention, the fins are easily caught on the contact surface, the movement of the fins in the pipe expansion process can be regulated by the frictional force, and the fin pitch can be adjusted to a desired state in the pipe expansion process.
In the pipe expansion device according to the eighth aspect of the invention, the fins can be sandwiched from both sides by the first holding member and the second holding member, and fluctuations in the fin pitch in the pipe expansion process can be further suppressed.

  In the pipe expansion device according to the ninth aspect of the invention, the frictional force acting on the fin and the friction surface is stronger, and fluctuations in the fin pitch in the pipe expansion process can be further suppressed.

<First Embodiment>
<Structure of tube expansion device>
A tube expansion device 1 according to a first embodiment of the present invention is shown in FIG. The tube expansion device 1 is a device that expands a heat transfer tube penetrating a fin and fixes the heat transfer tube and the fin in the manufacturing process of the heat exchanger, and the heat exchanger so that the heat transfer tube is parallel to the vertical direction. 2 is a so-called vertical tube expansion device. As shown in FIG. 2, the heat exchanger 2 expanded by the tube expansion device 1 includes two fixing plates 21 and 22, a plurality of fins 23, and a plurality of heat transfer tubes 24. The two fixed plates 21 and 22 are provided in parallel with each other in the vicinity of the end of the heat exchanger 2, and a hole through which the heat transfer tube 24 passes is provided. The plurality of fins 23 are stacked in parallel between the two fixing plates 21 and 22, and a plurality of holes through which the heat transfer tubes 24 pass are provided. The plurality of fins 23 each have a rectangular shape having a long end portion of two sides and a short end portion of two sides. In the tube expansion device 1, the fins 23 are arranged so that the long end portions of the two sides are aligned in the front-rear direction and the short end portions of the two sides are aligned in the left-right direction in the front view. The heat transfer tube 24 passes through the fixing plates 21 and 22 and the fins 23 perpendicular to the fixing plates 21 and 22 and the fins 23. The lower ends of the heat transfer tubes 24 are connected to each other by a U-shaped tube 25, and the upper ends are open ends. Moreover, the heat exchanger 2 which is the target of the pipe expansion process by the pipe expansion device 1 is a so-called two-row heat exchanger, and the heat transfer tubes 24 are arranged in two rows as shown in FIG. That is, the heat exchanger 2 is parallel to the first straight line L1 in the first row heat transfer tube group G1 having a plurality of heat transfer tubes 24 arranged so as to be arranged at equal intervals on the first straight line L1 in the axial cross section. A second row heat transfer tube group G2 having a plurality of heat transfer tubes 24 arranged at equal intervals on the second straight line L2 and a plurality of pipes connecting the lower ends of the plurality of heat transfer tubes 24 of the first row heat transfer tube group G1 to each other. The first U-shaped tube U1, the plurality of second U-tubes U2 connecting the lower ends of the plurality of heat transfer tubes 24 of the second row heat transfer tube group G2, the lower end of the heat transfer tubes 24 of the first row heat transfer tube group G1, and the second A plurality of third U-shaped tubes U3 are connected to the lower ends of the heat transfer tubes 24 of the row heat transfer tube group G2. In addition, the diameter of the heat transfer tube 24 before the pipe expansion process is slightly smaller than the holes provided in the fins 23 and the fixing plates 21 and 22, and the heat transfer pipe 24 and the fins 23 are fixed to each other when the heat transfer pipe 24 is subjected to the pipe expansion process. The

Returning to FIG. 1, the tube expansion device 1 includes a frame 3, a plurality of mandrels 4, a mandrel driving unit 5, a first fixing unit 6, a second fixing unit 7, and front and rear pressing plates 8.
[flame]
The frame 3 includes a base 31, a guide post 32, a mandrel guide body 33, an upper frame 34, intermediate plates 35 and 36, a rod 37, and the like. The base 31 constitutes the bottom of the frame 3, and four guide posts 32 are erected at four corners of the base 31. The guide post 32 is a columnar member extending in the vertical direction. The mandrel guide 33 is a member that guides the mandrel 4 described later, and is provided at an intermediate portion of the guide post 32. The intermediate plates 35 and 36 are members that guide the mandrel 4 in the same manner as the mandrel guide body 33, and have a first intermediate plate 35 and a second intermediate plate 36 that are arranged separately in the vertical direction. The intermediate plates 35 and 36 are provided between the mandrel guide body 33 and the upper frame 34 so as to be slidable with respect to the guide post 32, and are connected to each other by a rod 37. The mandrel guide body 33 and the intermediate plates 35 and 36 are provided with a hole through which the mandrel 4 passes at a position corresponding to the mandrel 4, and the mandrel 4 inserted into the hole is restricted from moving in the horizontal direction. 4 is supported. The upper frame 34 constitutes the top of the frame 3 and the upper end of the guide post 32 is connected and fixed.

[Mandrel]
The mandrels 4 are members inserted into the heat transfer tubes 24, and a plurality of mandrels 4 are provided corresponding to the number of the plurality of heat transfer tubes 24. Each of the plurality of mandrels 4 has a bar shape parallel to the vertical direction, and is provided so as to be movable in the vertical direction. A head portion 41 to be inserted into the heat transfer tube 24 is provided at the lower end of the mandrel 4, and the head portion 41 has a spherical shape having a larger diameter than other portions.

[Mandrel drive]
The mandrel driving unit 5 is a mechanism that moves the mandrel 4 in the vertical direction, and includes a main cylinder 51, a pressure frame 52, a pressing member 53, and the like. The main cylinder 51 is fixed to the upper frame 34 and has a cylinder body 54 that can be driven in the vertical direction. The pressure frame 52 is fixed to the tip of the cylinder body 54, and is slidably supported on the guide post 32 between the upper frame 34 and the intermediate plates 35 and 36. The pressing member 53 is attached to the pressure frame 52, and the plurality of mandrels 4 are attached to the lower surface of the pressing member 53 downward at a predetermined interval. Accordingly, when the cylinder body 54 of the main cylinder 51 is driven up and down, the pressure frame 52 and the pressing member 53 move up and down, and the mandrel 4 moves up and down accordingly.

[First fixed part]
The first fixing portion 6 is a portion that holds and fixes the upper end of the heat transfer tube 24, below the mandrel guide body 33, and in the vicinity of the upper end of the heat transfer tube 24 of the heat exchanger 2 installed in the tube expansion device 1. Is provided. As shown in FIG. 2, the first fixing portion 6 is configured by a clamp body that is provided so that the upper end of the heat transfer tube 24 can be clamped from a direction perpendicular to the axis, that is, from the horizontal direction. The heat transfer tube 24 is held by sandwiching the upper end from the horizontal direction.

[Second fixing part]
Returning to FIG. 1, the second fixing portion 7 is a portion that is locked and held by the U-shaped tube 25 that connects the lower end of the heat transfer tube 24, and is installed in the tube expansion device 1 above the base 31. It is provided in the vicinity of the U-shaped tube 25 of the heat exchanger 2. The 2nd fixing | fixed part 7 has the receiving stand 71, the latching pin 72 (refer FIG. 3), and the latching pin receiving member 73 (refer FIG. 3).

The cradle 71 is provided on the base 31, and the heat exchanger 2 installed in the pipe expansion device 1 is placed thereon. A plurality of recesses into which the U-shaped tube 25 is fitted are provided on the upper surface of the cradle 71.
As shown in FIG. 3, the plurality of locking pins 72 are rod-like members arranged in parallel to each other and have a semicircular cross section (see FIG. 2). The plurality of locking pins 72 are provided so as to be movable at least in the horizontal direction, are respectively inserted inside the plurality of U-shaped tubes 25, and are respectively locked to the plurality of U-shaped tubes 25 to lock the U-shaped tube 25. Support each from the inside. The plurality of locking pins 72 are inserted into the U-shaped tube 25 from a direction inclined with respect to a direction perpendicular to the U-shaped tube 25. Hereinafter, a part of the plurality of locking pins 72 will be described in detail with reference to FIG. 4 which is an enlarged view of the vicinity of the U-shaped tube 25 to which the locking pins 72 are locked.

  As described above, the plurality of heat transfer tubes 24 are arranged in two rows of the first row heat transfer tube group G1 and the second row heat transfer tube group G2, and the first row heat transfer tube group G1 is arranged in the axial cross-sectional view. It has the 1st heat exchanger tube P1, the 2nd heat exchanger tube P2, the 3rd heat exchanger tube P3, and the 4th heat exchanger tube P4 arranged in order on the 1 straight line L1 at predetermined intervals. The second row heat transfer tube group G2 has a fifth heat transfer tube P5, a sixth heat transfer tube P6, a seventh heat transfer tube P7, and an eighth heat transfer tube P8 that are arranged in order on the second straight line L2 with a predetermined interval in the axial sectional view. And have. The fifth heat transfer tube P5 is disposed away from the first heat transfer tube P1 in a direction that forms an angle α with the first straight line L1. The angle α is an angle in a range of 0 <α <90, and is about 60 degrees in FIG. The sixth heat transfer tube P6 is disposed away from the second heat transfer tube P2 in a direction that forms an angle α with the first straight line L1. The seventh heat transfer tube P7 is arranged away from the third heat transfer tube P3 in a direction that forms an angle α with the first straight line L1. The eighth heat transfer tube P8 is arranged away from the fourth heat transfer tube P4 in a direction that forms an angle α with the first straight line L1. Further, the first row heat transfer tube group G1 and the second row heat transfer tube group G2 are alternately arranged as viewed from the direction perpendicular to the first straight line L1 and the second straight line L2 (see solid arrow A1 in the figure). That is, when viewed from the direction perpendicular to the first straight line L1 and the second straight line L2, the sixth heat transfer pipe P6 is located between the first heat transfer pipe P1 and the second heat transfer pipe P2, and the seventh heat transfer pipe P7. Is located between the second heat transfer tube P2 and the third heat transfer tube P3, and the eighth heat transfer tube P8 is located between the third heat transfer tube P3 and the fourth heat transfer tube P4. In other words, the first heat transfer pipe P1 is located between the fifth heat transfer pipe P5 and the sixth heat transfer pipe P6 when viewed from the direction perpendicular to the first straight line L1 and the second straight line L2, The heat transfer tube P2 is located between the sixth heat transfer tube P6 and the seventh heat transfer tube P7, and the third heat transfer tube P3 is located between the seventh heat transfer tube P7 and the eighth heat transfer tube P8. Moreover, the 1st heat exchanger tube P1 and the 2nd heat exchanger tube P2 are connected by the 1st U-shaped tube U1. The sixth heat transfer tube P6 and the seventh heat transfer tube P7 are connected by a second U-shaped tube U2. The third heat transfer tube P3 and the eighth heat transfer tube P8 are connected by a third U-shaped tube U3. Accordingly, the first U-shaped tube U1 is disposed along the first straight line L1, the second U-shaped tube U2 is disposed along the second straight line L2, whereas the third U-shaped tube U3 is disposed along the first straight line L1. And they are arranged obliquely across the second straight line L2. The plurality of locking pins 72 pass between the fifth heat transfer tube P5 and the sixth heat transfer tube P6, and are inserted into the first U-shaped tube U1 and inside the second U-shaped tube U2. Is inserted into the second heat transfer tube P2 and the third heat transfer tube P3, passes between the seventh heat transfer tube P7 and the eighth heat transfer tube P8, and the inside of the third U-shaped tube U3. And a third locking pin 83 that passes between the third heat transfer tube P3 and the fourth heat transfer tube P4. The plurality of locking pins 81-83 are respectively arranged at an angle α with respect to the first straight line L1, and the first locking pin 81, the second locking pin 82, and the third locking pin 83 are The first straight line L1 is inserted into the first U-shaped tube U1, the second U-shaped tube U2, and the third U-shaped tube U3 from the direction that forms an angle α. The locking pins 81-83 are inserted inside the U-shaped tube U1-U3 until the tip protrudes on the opposite side of the U-shaped tube U1-U3.

  Returning to FIG. 3, the locking pin receiving member 73 is a member that receives the tip of the locking pin 72 inserted inside the U-shaped tube 25. The locking pin receiving member 73 is provided with a plurality of holes into which the tips of the plurality of locking pins 72 inserted inside the plurality of U-shaped tubes 25 are respectively inserted. Supports the tip of the locking pin 72 inserted into the hole and restricts the movement of the locking pin 72.

[Front and rear holding plate]
As shown in FIG. 5, the front and rear pressing plate 8 is a plate-like member arranged in parallel with the heat exchanger 2, and restricts the movement of the fins 23 in the tube expansion process. FIG. 5 is a side view of the heat exchanger 2 and the front and rear pressing plates 8. The front and rear pressing plate 8 has a front pressing plate 81 and a rear pressing plate 82. The front pressing plate 81 is disposed in front of the heat exchanger 2, and the rear pressing plate 82 is disposed behind the heat exchanger 2. At the time of the pipe expansion process, the front and rear pressing plates 8 are arranged so as to sandwich the heat exchanger 2 from the front and rear, and are urged in a direction to sandwich the fins 23 by a biasing means such as a spring. Further, the inner side surface of the front pressing plate 81 and the inner side surface of the rear pressing plate 82 are contact surfaces 82 and 83 that contact the front ends and the rear ends of the plurality of fins 23, respectively. The front holding plate 81 is in contact with the long end portion of the fin 23 located at the front end of the fin 23 and holds the front end portion of the fin 23. The rear pressing plate 82 contacts the long end portion of the fin 23 located at the rear end of the fin 23 and holds the rear end portion of the fin 23. Further, the front and rear pressing plates 8 have a size that covers the entire plurality of stacked fins 23 in a projected view as viewed from the direction perpendicular to the contact surfaces 82 and 83, respectively (see FIG. 1). That is, the front / rear pressing plate 8 has a vertical dimension larger than the total length of the plurality of fins 23 stacked in the vertical direction in the vertical direction. The front / rear pressing plate 8 is formed of a flexible foam material such as sponge or urethane.

<Operation in tube expansion processing>
The operation when the tube expansion process is performed by the tube expansion device 1 according to the present embodiment will be described mainly based on FIG.
First, the pressure frame 52 rises to the upper limit position, and the first fixing portion 6 is opened. Next, the heat exchanger 2 that has not been subjected to the pipe expansion process is placed on the cradle 71 with the open end of the heat transfer tube 24 facing up. At this time, the heat transfer tube 24 is located on the axial extension of the mandrel 4. The upper end of the heat transfer tube 24 is fixed by the clamp body of the first fixing portion 6, and the locking pin 72 of the second fixing portion 7 is fixed until the tip is inserted into the hole of the locking pin receiving base 71. Insert inside the tube 25. Thereby, the setting of the heat exchanger 2 is completed. In addition, the several fin 23 is arrange | positioned so that a fin pitch may become equal over the whole perpendicular direction of the heat exchanger 2 here. Further, the front and rear pressing plates 8 are attached so as to sandwich the front surface and the rear surface of the heat exchanger 2.

  Next, the mandrel 4 moves downward. At this time, the main cylinder 51 is driven and the pressure frame 52 is lowered. As a result, the mandrel 4 is lowered and the head portion 41 is inserted into the heat transfer tube 24. While the heat transfer tube 24 is expanded by the mandrel 4, a compressive force is applied to the heat transfer tube 24 to contract in the axial direction, that is, in the vertical direction, but the first fixing portion 6 and the second fixing portion 7 cause the heat transfer tube 24 to expand. Since both ends are fixed, contraction of the heat transfer tube 24 is prevented.

  When the pressure frame 52 is lowered to the positions of the upper intermediate plates 35 and 36, the upper first intermediate plate 35 is also lowered by being pressed by the pressure frame 52. The pressure frame 52 and the first intermediate plate 35 are both lowered to the position of the lower second intermediate plate 36. Finally, the pressure plate, the first intermediate plate 35, and the second intermediate plate 36 are moved to the mandrel guide frame 33. The tube is lowered to the position, and the tube expansion process ends. When the tube expansion process is completed, the pressure frame 52 is raised and the mandrel 4 is extracted from the heat transfer tube 24. And the 1st fixing | fixed part 6 and the 2nd fixing | fixed part 7 are open | released, and the heat exchanger 2 is removed from the pipe expansion apparatus 1. FIG.

The tube expansion process is performed by the operation as described above, and the fins 23 and the heat transfer tubes 24 are fixed.
<Characteristic>
(1)
In this pipe expansion device 1, the front and rear surfaces of the heat exchanger 2 are sandwiched between the front and rear pressing plates 8 in the pipe expansion process. For this reason, the downward movement of the fins 23 due to the deformation of the heat transfer tubes 24 is restricted by the front and rear pressing plates 8. Therefore, in the pipe expansion process, the fin pitch set before the fins 23 are pressed by the front and rear pressing plates 8 is maintained after the pipe expansion process. For this reason, when the fin pitch is set evenly before the fins 23 are pressed by the front and rear pressing plates 8, the fin pitch can be made to approach evenly in the vertical direction in the heat exchanger 2 after the pipe expansion process. Thereby, the abnormal noise produced at the time of ventilation can be reduced. Further, the appearance quality of the heat exchanger 2 is improved.

(2)
Since the front and rear pressing plates 8 that come into contact with the fins 23 are formed of a flexible foam material, it is possible to prevent an excessive force from being applied to the fins 23 and prevent the fins 23 from being broken.
Moreover, since the fin 23 can move when the force that the fin 23 tries to move by the tube expansion process exceeds the static frictional force between the fin 23 and the front and rear pressing plate 8, the fin 23 is excessive. Force is prevented from being applied. For this reason, destruction of the fin 23 can be prevented. Further, since the static frictional force between the fin 23 and the front / rear pressing plate 8 can be adjusted by adjusting the biasing force to the front / rear pressing plate 8, the front / rear pressing plate is prevented from breaking the fin 23. The biasing force to 8 may be adjusted.

Second Embodiment
In the above embodiment, the front and rear pressing plate 8 is formed of a flexible foam material, but the front and rear pressing plate 8 may be formed of a metal material, and fine irregularities may be provided on the surface thereof. For example, a flat metal plate provided with a plurality of fine grooves, or a flat metal plate whose surface is chemically or mechanically roughened may be used as the front / rear pressing plate 8. About another structure, it is the same as that of 1st Embodiment.

Even in this case, the fin pitch set before the fins 23 are pressed by the front and rear pressing plates 8 can be maintained even after the tube expansion process. Further, the effect relating to the prevention of the destruction of the fins 23 is the same as described above.
<Third Embodiment>
In the above embodiment, the front and rear pressing plates 8 are formed of a foam material having flexibility, but the front and rear pressing plates 8 may be formed of an elastic material. For example, the front / rear pressing plate 8 may be formed of sticky resin or rubber.

Other configurations are the same as those in the first embodiment.
Even in this case, the fin pitch set before the fins 23 are pressed by the front and rear pressing plates 8 can be maintained even after the pipe expansion process. Further, the effect relating to the prevention of the destruction of the fins 23 is the same as described above.
<Other embodiments>
(1)
In the first embodiment, the fin pitch is set to be equal before the tube expansion process in order to make the fin pitch close to each other. However, the fin pitch is not limited to the case where the fin pitch is equalized. It may be set differently. For example, before the pipe expansion process, the fins 23 are arranged densely in the upper part of the heat exchanger 2, and the fins 23 are arranged sparsely in the lower part of the heat exchanger 2. In this state, the heat exchanger 2 is sandwiched by the front and rear pressing plates 8 to perform a tube expansion process. Thereby, the fin pitch before the pipe expansion process is maintained after the pipe expansion process, and the heat exchanger 2 in which the upper fins 23 are dense and the lower fins 23 are sparse is manufactured. Thus, by adjusting the setting of the fin pitch before the tube expansion process, it is possible to adjust the fin pitch distribution to a desired mode.

(2)
In said 1st Embodiment, although the front-back pressing board 8 is formed from the foam material, only the inner surface of the front-back pressing board 8 may be formed from a foam material. For example, as the front / rear pressing plate 8, a metal plate-like member having a sheet formed of a foam material attached to the inner side surface may be used. The same applies to other materials as well as foamed materials.

(3)
In the above first embodiment, the front and rear pressing plates 8 sandwich the heat exchanger 2 from the front and rear, and the long ends of the fins 23, that is, the front and rear ends of the fins 23 are held by the front and rear pressing plates 8. However, the pipe expansion device 1 may be configured so that the left and right sides of the heat exchanger 2 are sandwiched between pressing plates and the short ends of the fins 23, that is, the left and right ends of the fins 23 are held by the pressing plates. . However, in order to hold the fins 23 more firmly, it is more desirable that the long ends of the fins 23 are held by the front and rear pressing plates 8 as in the first embodiment.

Further, the pipe expansion device 1 may be configured such that the four sides of the heat exchanger 2 are sandwiched between pressing plates, and all the end portions of the four sides of the fins 23 are held by the pressing plates.
(4)
Although the vertical tube expansion device 1 is shown in the above embodiment, the present invention can also be applied to a horizontal tube expansion device in which the heat transfer tubes 24 are arranged in parallel in the horizontal direction.

(5)
In the above embodiment, the locking pin 72 has a semicircular cross-sectional shape, but may have a circular cross section.
(6)
In the operation in the above tube expansion process, when the pressure frame 52 rises to the upper limit position and the first fixing portion 6 is opened, the first fixing portion 6 operates integrally with the mandrel guide body 33 and moves upward. Accordingly, the first fixing unit 6 may be temporarily retracted. In this case, the first fixing portion 6 moves downward together with the mandrel guide 33 to sandwich the heat transfer tube 24.

  The present invention has an effect that the fin pitch can be adjusted to a desired state in the tube expansion process, and is useful as a tube expansion device.

The front view of a pipe expansion apparatus. The heat exchanger which receives a pipe expansion process, and its surrounding block diagram. The bottom view of a heat exchanger and a 2nd fixing | fixed part. The enlarged view near the 2nd fixed part. The side view of a front-and-back pressing plate and a heat exchanger.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tube expansion apparatus 2 Heat exchanger 4 Mandrel 8 Front / rear holding member (holding member)
23 Fin 24 Heat Transfer Tube 81 Front Holding Member (First Holding Member)
82 Rear holding member (second holding member)
83,84 Contact surface

Claims (9)

In the heat exchanger (2) including a plurality of fins (23) provided with a plurality of holes and stacked, and a plurality of heat transfer tubes (24) inserted into the holes and penetrating the fins (23), the fins ( 23) a tube expansion device for expanding the heat transfer tube (24) inserted in the hole of 23) and fixing the fin (23) and the heat transfer tube (24),
A plurality of mandrels (4) inserted into the plurality of heat transfer tubes (24) to expand the heat transfer tubes (24);
A holding member (8) for holding both ends of the plurality of fins (23);
A tube expansion device (1). The holding member (8) has contact surfaces (83, 84) that come into contact with both ends of the fins (23).
The tube expansion device (1) according to claim 1. The fin (23) has a rectangular shape having two long ends and two short ends,
The contact surfaces (83, 84) are in contact with the long end portion,
The tube expansion device (1) according to claim 2. The contact surface (83, 84) has a size covering the whole of the plurality of stacked fins (23) in a projection view as viewed from a direction perpendicular to the contact surface (83, 84).
The tube expansion device (1) according to claim 2 or 3. The contact surfaces (83, 84) are formed of a flexible foam material.
The tube expansion device (1) according to any one of claims 2 to 4. The contact surfaces (83, 84) are formed of a metal material, and fine irregularities are provided on the surface.
The tube expansion device (1) according to any one of claims 2 to 4. The contact surfaces (83, 84) are formed of an elastic material.
The tube expansion device (1) according to any one of claims 2 to 4. The holding member (8) includes a first holding member (81) that holds one end of the plurality of fins (23), and a second holding member (82) that holds the other end of the plurality of fins (23). Having
The pipe expansion device (1) according to any one of claims 1 to 7. The first holding member (81) and the second holding member (82) are biased in a direction sandwiching the fin (23).
Tube expansion device (1) according to claim 8.

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