A tube expanding machine

Abstract

A tube expander, comprising an expansion head mechanism and an expansion head reciprocating drive mechanism; the expansion head mechanism comprises an expansion head and an expansion rod; the expansion head is hollow and a limiting step is arranged in the hollow, and a plurality of equally divided radially penetrating gaps are arranged at the front end of the expansion head shell; the expansion rod comprises a first rod body and a second rod body, the first rod body is provided with a support section and a boss, and the tail end of the first rod body is threadedly connected with the front end of the second rod body; the expansion head is sleeved outside the expansion rod, and when it moves axially to one end, it is limited by the front end of the second rod body, and when it moves to the other end, the boss of the first rod body blocks the expansion head limiting step, and at the same time, the support section enters the front end of the expansion head to open the radial opening gap; the expansion head drive mechanism is connected to the tail end of the second rod body of the expansion head mechanism and moves back and forth. The expansion head mechanism of the tube expander of the present invention is simpler and easy to disassemble and assemble.

Description

Technical Field

[0001] The invention relates to a head expansion mechanism and a tube expansion machine thereof, and is particularly suitable for expanding straight tubes of a heat exchanger. Background Art

[0002] The expansion head is an essential component for expanding the heat exchanger tube. It enters the copper tube through the expansion head to force the copper tube to expand, so that the copper tube and the heat exchanger fins of the outer jacket are tightly combined to enhance the heat exchange rate of the heat exchanger.

[0003] This type of mechanical tube expansion is generally divided into two types: push expansion and pull expansion. Push expansion refers to pushing the expansion head gradually into the copper tube to expand the tube, and pull expansion refers to pulling the expansion head gradually out of the copper tube to expand the tube. At present, push expansion is widely used. Its applied equipment includes vertical tube expanders and horizontal tube expanders. The heat exchanger products expanded are mostly small and medium-sized heat exchangers. Large and super-large heat exchanger products with a length of more than ten meters are difficult to expand due to the limitations of tube expansion equipment. Therefore, pull expansion and its applied tube expander have outstanding advantages in the expansion of large and super-large heat exchanger products. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the above-mentioned defects of the prior art and provide a tube expander with a simple structure and convenient assembly and disassembly.

[0005] The technical solution adopted by the present invention to solve the above technical problems is:

[0006] A tube expander, characterized in that: it includes an expansion head mechanism and an expansion head reciprocating drive mechanism; the expansion head mechanism includes an expansion head and an expansion rod; the expansion head is hollow and a limiting step is set in the hollow, and a plurality of equally divided radially penetrating gaps are set at the front end of the expansion head shell; the expansion rod includes a first rod body and a second rod body, the first rod body is provided with a support section and a boss, and the tail end of the first rod body is threadedly connected with the front end of the second rod body; the expansion head is sleeved outside the expansion rod, and when it moves axially to one end, it is limited by the front end of the second rod body, and when it moves to the other end, the boss of the first rod body blocks the expansion head limiting step, and at the same time, the support section enters the front end of the expansion head to open the radial opening gap; the expansion head reciprocating drive mechanism connects the tail end of the second rod body of the expansion head mechanism and moves back and forth. Preferably, a bullet-shaped end is also set in front of the support section of the above-mentioned first rod body, and the bullet-shaped end can facilitate the expansion rod to enter the copper tube.

[0007] Preferably, the plurality of radially penetrating slits are evenly distributed along the circumferential direction.

[0008] More specifically, the above-mentioned expanding head reciprocating drive mechanism includes a motor, a gear, a rack, a motor mounting plate, and a support; the motor is installed on the motor mounting plate, a gear is installed on its output shaft, and the rack meshing with the gear is installed on the support, and the tail end of the second rod body of the expanding head mechanism is fixed on the motor mounting plate.

[0009] Preferably, a guide mechanism is provided between the support and the motor mounting plate, wherein the guide mechanism comprises a slide rail and a slide seat, the slide rail is installed on the support, and the slide seat matching the slide rail is installed on the motor mounting plate, so that the motor mounting plate and the expansion head mechanism connected and fixed thereto can move more smoothly.

[0010] Preferably, the tail end of the second rod of the expansion mechanism is mounted on an expansion rod fixing seat, and the expansion rod fixing seat is mounted on the motor mounting plate.

[0011] Preferably, the support is further provided with a translation driving mechanism, and the support and the expansion mechanism on the support are moved by the translation driving mechanism.

[0012] More specifically, the translation drive mechanism includes a translation driver and a translation transmission mechanism, and the driver drives the support through the translation transmission mechanism to make the support translate.

[0013] More specifically, the translation driver is a second motor, the translation transmission is a second gear and a second rack, the second gear is mounted on the output shaft of the second motor and meshes with the second rack, and the second rack is fixed on the support.

[0014] Preferably, the support is also provided with a lifting drive mechanism, and the support and the expanding head mechanism thereon are driven to rise and fall by the lifting drive mechanism.

[0015] More specifically, the lifting drive mechanism includes a lifting drive and a lifting transmission mechanism, and the lifting drive drives the support through the lifting transmission mechanism to lift the support.

[0016] More specifically, the driver is a motor, and the lifting transmission mechanism is a worm gear lift, a lead screw, and a nut. The motor output shaft is connected to the worm gear lift, the worm gear lift is equipped with a lead screw, and the nut is sleeved on the lead screw and connected to the support.

[0017] Preferably, there are two groups of worm gear elevators, screw rods and nuts, and the two worm gear elevators are connected by a horizontal transmission shaft.

[0018] More specifically, the reciprocating drive mechanism and the translation drive mechanism may also be a pneumatic cylinder, a hydraulic cylinder or other drive mechanisms, and the lifting mechanism may also be a pneumatic cylinder, a hydraulic cylinder or other drive mechanisms.

[0019] Compared with the prior art, the invention has the advantages that the expansion head mechanism of the tube expander is simpler and convenient to assemble and disassemble. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the three-dimensional structure of the tube expander according to an embodiment of the present invention.

[0021] Figure 2Schematic diagram of the expansion mechanism according to an embodiment of the present invention.

[0022] Figure 3 Schematic diagram of the expansion head of the expansion head mechanism according to an embodiment of the present invention.

[0023] Figure 4 Schematic diagram of the expansion rod of the expansion head mechanism according to an embodiment of the present invention.

[0024] Figure 5-Figure 8 This is a diagram of the tube expansion process of the expansion head mechanism according to an embodiment of the present invention.

[0025] Fig. 9 for Figure 1 Magnified view of section A.

[0026] Fig.10 It is a schematic structural diagram of a side view of a tube expander according to an embodiment of the present invention. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below with reference to the accompanying drawings.

[0028] like Figure 1 , 2 As shown, the tube expander includes: an expansion head mechanism, an expansion head driving mechanism 3, and a support 4.

[0029] The expansion head mechanism comprises: an elastic expansion head 1 and an expansion rod 2.

[0030] The elastic expansion head 1 is hollow with a step 102 in the hollow. One end of the shell is provided with a plurality of equally divided radial opening gaps 101 which can be elastically compressed, and the other end is provided with a boss section 103 .

[0031] The natural opening size D1 of the elastic expansion head 1 determines the expansion size of the copper tube. The diameter of the boss section 103 must be strictly matched with the inner diameter of the copper tube 10. If it is too large, it will not be able to enter the copper tube 10, and if it is too small, it will not be able to expand.

[0032] The expansion rod 2 includes a first rod body 21 and a second rod body 22. The first rod body 21 includes a bullet-shaped end 201 to facilitate the expansion rod to enter the copper tube, and also includes a support section 202, a boss surface 203, and a threaded section 204. The first rod body 21 is threadedly connected to the second rod body 22 through its threaded section 204.

[0033] The elastic expansion head 1 is sleeved outside the expansion rod 2, and its axial movement position is limited at one end by the end surface 205 of the second rod body 22, and at the other end by the boss surface 203 of the first rod body 21 blocking the step 102.

[0034] like Figure 2The figure shows the state of the expansion head and the tube, D1 is the expansion size, and the size D1 when the elastic expansion head 1 is naturally opened is maintained by the support section 202 of the first rod body 21 during the expansion.

[0035] like Figure 1 and Fig. 9 As shown, the expansion head driving mechanism 3 includes a motor 301 , a gear 302 , a rack 303 , a motor mounting plate 304 , a slide rail 305 , and a slide seat 306 .

[0036] The motor 301 is mounted on a motor mounting plate 304 , a gear 302 is mounted on its output shaft, a rack meshing with the gear 302 is mounted on a support 4 , the slide rail 305 is mounted on the support 4 , and a corresponding slide 306 is mounted on the motor mounting plate 304 .

[0037] One end of the expansion rod 2 of the expansion mechanism is mounted on the expansion rod fixing seat 307 , and the expansion rod fixing seat 307 is mounted on the motor mounting plate 304 .

[0038] The motor 301 drives the gear 302 to rotate, and through the action of the gear rack 303 meshing therewith, the expansion mechanism moves along the axial direction of the expansion rod 2.

[0039] Action process:

[0040] like Figure 5 In the state shown, the expansion head driving mechanism pushes the expansion head mechanism into the copper tube, the elastic expansion head 1 is compressed, and due to the friction between the boss section 103 and the inner diameter of the copper tube, the elastic expansion head 1 will press against the end surface 205.

[0041] like Figure 6 In the state shown, the expansion head driving mechanism 3 pushes the expansion head mechanism out of the copper tube until the boss section 103 of the elastic expansion head completely comes out of the copper tube. At this time, the elastic expansion head 1 opens naturally. Since the maximum diameter of the expansion head mechanism is smaller than the inner diameter of the copper tube, it can pass through the copper tube smoothly.

[0042] like Figure 7 As shown, after the elastic expansion head 1 is pushed out, the expansion head driving mechanism 3 starts to pull the expansion head mechanism back. Due to the friction between the boss section 103 and the inner diameter of the copper tube, the elastic expansion head 1 moves slower than the expansion rod, so the elastic expansion head 1 moves in the opposite direction of the expansion rod for a distance, so that the slit at the front end of the elastic expansion head 1 is stuck at the support section 202 of the expansion rod until the boss surface 203 blocks it from moving. At this time, the elastic expansion head maintains the expansion tube size D1 through the support of the support section 202, and is ready for expansion.

[0043] like Figure 8 As shown, the expansion head driving mechanism 3 continues to pull the expansion head mechanism into the copper tube to expand the copper tube until the entire copper tube is expanded, and then is pulled out of the copper tube to prepare for the next expansion.

[0044] like Figure 1 As shown, in order to allow the expansion rod to smoothly enter and exit the copper tube, the expansion rod 2 can be supported by a plurality of support blocks 308 , each of which is correspondingly mounted on a slide seat 306 , so that the support block 308 can move smoothly along the slide rail 305 .

[0045] According to the change of workpiece specifications, sometimes the support 4 and the expanding head mechanism thereon need to move horizontally or up and down as a whole, so a translation drive mechanism and a lifting drive mechanism can be added, and the translation drive mechanism and the lifting drive mechanism are both installed on the frame 7.

[0046] The translation drive mechanism includes a motor 501, a gear 502, and a rack 503. The motor is mounted on a lifting frame 606, and a gear 502 is mounted on its output shaft, and a rack 503 meshing with the gear 502 is mounted on a support 4.

[0047] In order to enable the support to move smoothly, a slide rail and slide guide mechanism 504 is provided between the support 4 and the lifting frame 606 .

[0048] The lifting drive mechanism includes a motor 601 , a worm gear lift 602 , a lead screw 603 , a coupling 604 , a transmission shaft 605 and a lifting frame 606 .

[0049] The worm gear lift 602, the screw rod 603 and the lifting frame 606 are symmetrically arranged on the frame 7. Fig.10 The motor 601 is mounted on the frame 7, and its output shaft is connected to the worm gear lift 602 on one side, one end of the screw rod 603 is connected to the lift 602, and the other end is connected to the lift frame 606, and both ends of the transmission shaft 605 are connected to the worm gear lift 602 through the coupling 604.

[0050] The motor 601 drives the worm gear lift 602 on one side to drive the screw rod 603 to move up and down. At the same time, the transmission shaft 605 drives the worm gear lift 602 on the other side to drive the screw rod 603 to move up and down, thereby realizing the up and down movement of the lifting frames 606 on both sides.

Claims

1. A tube expander, characterized in that: It includes an expanding head mechanism and an expanding head reciprocating drive mechanism; the expanding head mechanism includes an expanding head and an expanding rod; the expanding head is hollow and a limiting step is arranged in the hollow, and a plurality of equally divided radially penetrating gaps are arranged at the front end of the expanding head shell; the expanding rod includes a first rod body and a second rod body, the first rod body is provided with a supporting section and a boss, and the tail end of the first rod body is threadedly connected with the front end of the second rod body; the expanding head is sleeved outside the expansion rod, and when it moves axially to one end, it is limited by the front end of the second rod body, and when it moves to the other end, the boss of the first rod body blocks the expanding head limiting step, and at the same time, the supporting section enters the front end of the expanding head to open the radial opening gap; the expanding head reciprocating drive mechanism is connected to the tail end of the second rod body of the expanding head mechanism and moves back and forth.

2. The tube expander according to claim 1, characterized in that: A bullet-shaped end is also arranged in front of the supporting section of the first rod body.

3. The tube expander according to claim 1, characterized in that: The expansion head reciprocating drive mechanism includes a motor, a gear, a rack, a motor mounting plate, and a support; the motor is mounted on the motor mounting plate, a gear is mounted on its output shaft, and a rack meshing with the gear is mounted on the support, and the tail end of the second rod body of the expansion head mechanism is fixed on the motor mounting plate.

4. The tube expander according to claim 3, characterized in that: A guide mechanism is arranged between the support and the motor mounting plate. The guide mechanism comprises a slide rail and a slide seat. The slide rail is mounted on the support, and the slide seat matched with the slide rail is mounted on the motor mounting plate.

5. The tube expander according to claim 1, characterized in that: The tail end of the second rod body of the expansion mechanism is installed on the expansion rod fixing seat, and the expansion rod fixing seat is installed on the motor mounting plate.

6. The tube expander according to claim 3, characterized in that: The support is provided with a translation driving mechanism, and the support and the expansion head mechanism on the support are moved by the translation driving mechanism.

7. The tube expander according to claim 6, characterized in that: The translation drive mechanism comprises a translation driver and a translation transmission mechanism. The driver drives the support through the translation transmission mechanism to make the support translate.

8. The tube expander according to claim 7, characterized in that: The translation driver is a second motor, and the translation transmission is a second gear and a second rack. The second gear is installed on the output shaft of the second motor and meshes with the second rack, and the second rack is fixed on the support.

9. The tube expander according to claim 3, characterized in that: The support is provided with a lifting drive mechanism, and the support and the expanding head mechanism thereon are driven to rise and fall by the lifting drive mechanism.

10. The tube expander according to claim 9, characterized in that: The lifting drive mechanism comprises a lifting drive and a lifting transmission mechanism. The lifting drive drives the support through the lifting transmission mechanism to make the support rise and fall.

Images