Heat exchanger tube plate welding equipment

Abstract

The invention provides heat exchanger tube plate welding equipment, and belongs to the technical field of heat exchanger welding equipment. The heat exchanger tube plate welding equipment comprises a positioning device, the positioning device comprises a positioning cylinder extending into an inner hole of a heat exchange tube, at least one perforation group is formed in the cylinder wall of the positioning cylinder, each perforation group comprises at least three perforations which are formed in the circumferential direction of the positioning cylinder at intervals, and a positioning piece is arranged in each perforation; one end of the positioning piece is located outside the positioning barrel and provided with a jacking face used for jacking the inner hole wall of the heat exchange pipe, and the other end of the positioning piece is located inside the positioning barrel and is in transmission connection with a driving mechanism used for driving the positioning piece to stretch and move in the radial direction of the positioning barrel. According to the heat exchanger tube plate welding equipment, the heat exchange tube can be accurately positioned, the welding quality is guaranteed, the positioning piece abuts against the inner hole wall of the heat exchange tube, a high-temperature area near a tube opening is avoided, and deformation of the tube opening is avoided. Meanwhile, the positioning cylinder does not occupy too much external space of the heat exchange tube, so that the welding gun can avoid the positioning device.

Description

Technical Field

[0001] The invention relates to heat exchanger tube plate welding equipment, belonging to the technical field of heat exchanger welding equipment. Background Art

[0002] Tube-sheet heat exchangers are a common type of heat exchanger in the petrochemical industry. Welding, a crucial step in the production process, significantly impacts the lifespan and safety of the heat exchanger. However, due to the large number of tube bundles in large tube-sheet heat exchangers, manual welding not only increases costs but also poses uncertainties in weld quality.

[0003] To address the above issues, a Chinese invention patent application, publication number CN116275778A, discloses a positioning device for an automatic heat exchanger tube sheet welder. The device comprises an automatic welder body and a welding gun. The head of the automatic welder body is connected to a fixed base. The fixed base is provided with a first movable block, a second movable block, and a third movable block. The third movable block is fixed to a connecting rod. The end of the connecting rod is provided with an electromagnet. The electromagnet includes a conical head. A rotating disk is provided on the outer surface of the connecting rod for rotation. The rotating disk is connected to a U-shaped plate via a cylinder. The welding gun is mounted on the U-shaped plate via an angle adjustment mechanism. When in use, the conical head is inserted into the inner hole of the heat exchange tube under the movement of the fixed base. The conical surface abuts against the tube mouth. When the electromagnet is energized, it can adsorb and fix the heat exchange tube, thereby positioning the heat exchange tube. Then, the welding gun is adjusted to a suitable angle to ensure that the welding gun head is at the welding point between the heat exchange tube and the tube sheet. The rotating disk is then driven to rotate by a motor and a gear structure. The rotating disk drives the welding gun to rotate synchronously. The welding gun rotates one circle to weld the heat exchange tube and the tube sheet.

[0004] The automatic welding machine body (i.e., the welding equipment body) positions the heat exchange tube by inserting the electromagnet's conical head (i.e., the positioning device) into the inner bore of the heat exchange tube. The conical head and the heat exchange tube are in line contact, allowing them to swing freely relative to each other. Even if the axis of the conical head is not coaxial with the axis of the heat exchange tube, the conical head can still be inserted into the inner bore of the heat exchange tube, resulting in poor positioning accuracy. Furthermore, the conical head presses against the nozzle of the heat exchange tube, which is located near the welding area. During welding, the temperature in this area is high, which can easily cause the nozzle to deform, affecting the welding quality. Furthermore, the large end of the conical head is located outside the heat exchange tube, occupying a large space. The welding gun needs to avoid the conical head, which affects the layout and installation of the welding gun and the welding operation. Summary of the Invention

[0005] The purpose of the present invention is to provide a heat exchanger tube sheet welding device to solve the problem in the prior art that the positioning device presses against the tube mouth of the heat exchange tube and the temperature in the area near the tube mouth is high during welding, which causes the tube mouth to be easily deformed and affects the welding quality.

[0006] To achieve the above objectives, the heat exchanger tube sheet welding equipment in the present invention adopts the following technical solutions: A heat exchanger tube sheet welding device includes a welding device body and a positioning device arranged on the welding device body, the positioning device includes a positioning cylinder for extending into the inner hole of the heat exchange tube, at least one group of perforation groups is opened on the cylinder wall of the positioning cylinder, one group of perforation groups includes at least three perforations arranged at intervals along the circumference of the positioning cylinder, and a positioning piece is provided in each perforation, one end of the positioning piece is located outside the positioning cylinder and is provided with a pressing surface for pressing the inner hole wall of the heat exchange tube, and the other end of the positioning piece is located inside the positioning cylinder and is transmission-connected to a driving mechanism for driving the positioning piece to move radially along the positioning cylinder.

[0007] The beneficial effect of the above technical solution is that: the present invention provides an improved heat exchanger tube sheet welding device, the improvement is that the positioning device includes a positioning cylinder for extending into the inner hole of the heat exchange tube, and at least one group of perforation groups is opened on the cylinder wall of the positioning cylinder, and one group of perforation groups includes at least three perforations, and each perforation is provided with a positioning member, so that there are at least three positioning members; one end of the positioning member is located outside the positioning cylinder and this end is provided with a pressing surface for pressing the inner hole wall of the heat exchange tube, so that the heat exchange tube can be positioned by pressing the inner hole wall of the heat exchange tube by more than three positioning members; and the other end of the positioning member is located inside the positioning cylinder and this end is transmission-connected to a driving mechanism for driving the positioning member to move radially along the positioning cylinder, so that under the control of the driving mechanism, the positioning member can extend and retract, and when extended, it presses the inner hole wall of the heat exchange tube to position it, and when retracted, it is convenient for the positioning cylinder to enter the inner hole of the heat exchange tube or exit from the inner hole of the heat exchange tube. In summary, since the three or more positioning parts in the present invention extend into the inner hole of the heat exchange tube along with the positioning tube, the pressure is on the inner hole wall of the heat exchange tube closer to the inside, rather than the tube mouth, which can avoid the high temperature area near the tube mouth and avoid the problem of easy deformation of the tube mouth and affecting the welding quality.

[0008] Furthermore, the driving mechanism includes a driving disc and a rotation control structure for controlling the rotation of the driving disc, and the driving disc and the positioning member are engaged with each other through a planar thread transmission.

[0009] Furthermore, the rotation control structure includes a driving rod fixedly connected to the center of the driving disk and a rotation power source transmission-connected to the driving rod to control the rotation of the driving rod.

[0010] Furthermore, the driving rod passes through the driving disk, and at least two driving disks are fixed at intervals along the axial direction of the driving rod. There are at least two groups of perforation groups, and each group of perforation groups is arranged at intervals along the axial direction of the positioning cylinder and corresponds one to one to the driving disk.

[0011] Furthermore, a fixing seat is fixedly arranged in the positioning cylinder, and a guide groove extending radially along the positioning cylinder is provided on the fixing seat. One end of the positioning member located in the positioning cylinder is guided and slidably installed in the guide groove; at least two fixing seats are fixed at intervals along the axial direction of the positioning cylinder, and the fixing seats correspond one-to-one to the driving disk.

[0012] Furthermore, a fixing seat is fixedly provided in the positioning cylinder, and a guide groove extending radially along the positioning cylinder is provided on the fixing seat. One end of the positioning member located in the positioning cylinder is guided and slidably installed in the guide groove.

[0013] Furthermore, the top pressure surface is a curved surface.

[0014] Furthermore, the positioning member includes a positioning member body and a thermal insulation pad fixed to the end of the positioning member body, and the surface of the thermal insulation pad constitutes the top pressure surface.

[0015] Furthermore, the rotary power source is fixedly arranged on the welding equipment body, the rotary power source and the driving rod are detachably connected via a coupling, and the positioning cylinder and the welding equipment body are detachably connected via bolts.

[0016] Furthermore, the welding equipment body includes a camera for identifying unwelded tube sheet holes. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of the structure of an embodiment of a heat exchanger tube sheet welding device according to the present invention; Figure 2 for Figure 1 A perspective view of the positioning device; Figure 3 for Figure 1 Cross-section view of the center locating mechanism (showing only one set of locating pins, a drive plate, and a mounting bracket).

[0018] In the figure: 1. Main controller; 2. Hydraulic press; 3. Base; 4. Lifting platform; 5. Spindle; 6. Second robotic arm; 7. Positioning device; 7-1. Positioning cylinder; 7-2. Positioning pin; 7-3. Driving rod; 7-4. Driving disk; 7-5. Fixed seat; 8. Welding gun; 9. Rotating axis; 10. Camera; 11. Fixed axis; 12. Wire feeding mechanism; 13. First robotic arm; 14. First rotating axis; 15. Second rotating axis; 16. Heat exchange tube; 17. Tube sheet. DETAILED DESCRIPTION

[0019] The features and performance of the present invention are further described in detail below with reference to the embodiments.

[0020] The positioning device of the heat exchanger tube sheet welding equipment of the present invention extends into the inner hole of the heat exchange tube when in use. By controlling a plurality of positioning pins evenly distributed around the circumference to extend and press against the inner hole wall of the heat exchange tube, the heat exchange tube is positioned, ensuring that the axis of the heat exchange tube is coaxial with the rotation axis of the welding gun, thereby achieving precise positioning. In addition, because the positioning pins press against the inner hole wall of the heat exchange tube rather than the tube mouth, the high-temperature area near the tube mouth is avoided, and deformation of the tube mouth can be prevented. At the same time, the positioning cylinder of the positioning device is cylindrical and extends into the inner hole of the heat exchange tube. Compared with the conical head in the prior art, it reduces the space occupied by the external space of the heat exchange tube, which helps the welding gun avoid the positioning device.

[0021] Embodiments of the heat exchanger tube sheet welding equipment of the present invention: like Figure 1 As shown, the heat exchanger tube sheet welding equipment includes a controller 1, a hydraulic press 2, a base 3, a lifting platform 4, a main shaft 5, a first robotic arm 13, a second robotic arm 6, a wire feeding structure 12, a positioning device 7, a camera 10, and a welding gun 8.

[0022] The hydraulic press 2 is connected to a lifting platform 4, which is mounted on a base 3. A spindle 5 is mounted on the lifting platform 4. The hydraulic press 2 can control the spindle 5 through the lifting platform 4 to achieve up and down movement. The spindle 5 controls the movement of the first robotic arm 13 via a first rotating shaft 14. The first robotic arm 13 is connected to the second robotic arm 6 via a second rotating shaft 15. The rotation axis of the first rotating shaft 14 extends vertically, while the rotation axis of the second rotating shaft 15 extends horizontally, ensuring that the second robotic arm 6 can move in any direction. The second robotic arm 6 is fixedly connected to the positioning device 7, and the second robotic arm 6 can control the positioning device 7 to move in any direction.

[0023] Furthermore, a rotating shaft 9 is mounted on the second robotic arm 6, and a welding gun 8 is mounted on the rotating shaft 9. The welding gun 8 is connected to a wire feed mechanism 12, thereby improving the degree of automation. The rotating shaft 9 can perform circular motion in the same plane and reciprocating motion in the vertical direction around the positioning device 7. For example, a rotating ring is rotatably mounted on the outside of the second robotic arm 6, and the rotating ring is driven to rotate by a gear mechanism. The rotating shaft 9 is fixedly connected to the rotating ring via a cylinder, a hydraulic cylinder, or an electric push rod. The specific structure and principle are the same as those in patent document CN116275778A.

[0024] Furthermore, a fixed shaft 11 is installed on the second robotic arm 6, and a camera 10 is installed on the fixed shaft 11. A protective device (not shown in the figure) is installed outside the lens of the camera 10 to extend the service life of the camera 10. The camera 10 adopts a high-definition camera mode to identify unwelded tube sheet holes.

[0025] The above parts except the positioning device 7 constitute the welding equipment body of the heat exchanger tube sheet welding equipment. The structure of the positioning device 7 is as follows: Figure 2 and Figure 3 As shown, it includes a positioning cylinder 7-1 for extending into the inner hole of the heat exchange tube 16, wherein the heat exchange tube 16 is inserted into the mounting hole (i.e., the tube plate hole) of the tube sheet 17. It should be noted that Figure 2 The tube sheet 17 is simplified as a tubular structure in order to conveniently illustrate the penetration relationship between the tube sheet 17 and the heat exchange tubes 16. In fact, the tube sheet 17 is a plate-like structure.

[0026] The positioning cylinder 7-1 is cylindrical, and has at least one set of perforations on its wall. In this embodiment, there are three sets of perforations, which are spaced apart along the axial direction of the positioning cylinder 7-1. In other embodiments, there may be two or one sets, or four or more sets. Each perforation set includes at least three perforations spaced apart along the circumference of the positioning cylinder 7-1. In this embodiment, each perforation set includes four perforations, and the four perforations are evenly spaced along the circumference of the positioning cylinder 7-1. In other embodiments, no matter how many perforation sets there are, the number of perforations in each perforation set can be three and evenly distributed around the circumference, or five, six, or more, and can be evenly distributed or unevenly distributed around the circumference.

[0027] A positioning piece is provided in each through-hole, and thus the positioning pieces are divided into three groups, each group including four pieces, and the four positioning pieces are evenly distributed around the circumference. Specifically, the positioning piece in this embodiment is a positioning pin 7-2, one end of which is located outside the positioning cylinder 7-1 and this end is provided with a pressing surface for pressing against the inner hole wall of the heat exchange tube 16. Furthermore, the positioning pin 7-2 includes a positioning pin body and a thermal insulation pad fixed to the end of the positioning pin body, and the surface of the thermal insulation pad constitutes the above-mentioned pressing surface. This can prevent the high temperature of the heat exchange tube 16 during welding from being transferred to the positioning pin 7-2, thereby ensuring the service life of the positioning pin 7-2, and can also avoid damage to the inner hole wall of the heat exchange tube 16. Furthermore, the above-mentioned top pressure surface is an arc-shaped surface, specifically a spherical surface, which facilitates the positioning pin 7-2 to press against the inner hole wall of the heat exchange tube 16, that is, there is point contact between the top pressure surface of a single positioning pin 7-2 and the inner hole wall of the heat exchange tube 16, and precise positioning is achieved by using multiple groups of positioning pins 7-2 arranged along the axial direction.

[0028] The other end of the locating pin 7-2 is located inside the locating cylinder 7-1 and this end is transmission-connected to a driving mechanism for driving the locating pin 7-2 to move radially telescopically along the locating cylinder 7-1. In this embodiment, the driving mechanism includes a driving disk 7-4 and a rotation control structure for controlling the rotation of the driving disk 7-4. The driving disk 7-4 and the locating pin 7-2 are matched through a flat thread transmission, that is, a thread structure is provided on the flat side surface of one end of the locating pin 7-2 located inside the locating cylinder 7-1, and a thread structure that cooperates with it is provided on the end face of the driving disk 7-4 facing the four locating pins 7-2 in the same group. The rotation of the driving disk 7-4 can drive each locating pin 7-2 to move radially telescopically along the locating cylinder 7-1.

[0029] To guide the movement of the positioning pins 7-2, a fixed seat 7-5 is fixedly installed within the positioning cylinder 7-1. The fixed seat 7-5 is provided with a guide groove extending radially along the positioning cylinder 7-1. The end of the positioning pin 7-2 located within the positioning cylinder 7-1 is guided and slidably mounted within the guide groove. Since the positioning pins 7-2 are arranged in three groups along the axial direction of the positioning cylinder 7-1, three fixed seats 7-5 are also provided. The three fixed seats 7-5 are arranged axially along the positioning cylinder 7-1, and each fixed seat 7-5 is provided with four guide grooves evenly distributed around the circumference to guide the four positioning pins 7-2 in the same group.

[0030] The above-mentioned rotation control structure includes a driving rod 7-3 fixedly connected to the center of the driving disk 7-4 and a rotating power source that is transmission-connected to the driving rod 7-3 to control the rotation of the driving rod 7-3. The rotating power source is fixedly set on the second robotic arm 6, that is, the rotating power source is fixedly set on the welding equipment body. The rotating power source is specifically a motor, and the output shaft of the motor is detachably connected to the driving rod 7-3 through a coupling.

[0031] In this embodiment, the driving rod 7-3 passes through the driving disk 7-4, and three driving disks 7-4 are fixed at intervals along the axial direction of the driving rod 7-3 to correspond to three groups of positioning pins 7-2, that is, one driving disk 7-4, one group of positioning pins 7-2, one fixing seat 7-5, and one group of perforated groups. These four correspond one to one, wherein the fixing seat 7-5 is an annular seat, and the driving rod 7-3 passes through the inner hole of the annular seat.

[0032] To facilitate assembly and connection, the fixing seat 7-5 is fixed to the positioning tube 7-1 by screws. Specifically, the screws pass through the wall of the positioning tube 7-1 and are connected to the threaded holes on the fixing seat 7-5. To prevent the screw heads from protruding, the screw holes on the wall need to be set as countersunk holes. In addition, the drive rod 7-3 and the drive disk 7-4 are connected by a threaded structure. To prevent loosening after connection or changes in the relative position of the two, glue can be applied to the threaded gap between the two after the drive disk 7-4 is connected in place. In addition, the positioning tube 7-1 and the second robot arm 6 are detachably connected by bolts. This not only facilitates installation, but also allows the positioning device 7 to be replaced to adapt to the positioning of heat exchange tubes of different diameters.

[0033] The working process of the heat exchanger tube sheet welding equipment in the present invention is as follows: Before welding begins, install the positioning device 7, connect the drive rod 7-3 to the motor via a coupling, and securely connect the positioning cylinder 7-1 to the second robotic arm 6 via bolts. Then, turn on the main controller 1 to ensure that it can operate normally. The operating program for the main controller 1 is then set. The main controller 1 controls the lifting platform 4 and the spindle 5 to control the first robotic arm 13, which in turn controls the movement of the second robotic arm 6. When the camera 10 identifies an unwelded tube sheet 17, the second robotic arm 6 automatically controls the positioning device 7 to enter the heat exchange tube 16. As the positioning device 7 enters the heat exchange tube 16, the motor on the second robotic arm 6 controls the drive rod 7-3 to rotate. Since the driving disk 7-4 and the positioning pin 7-2 are matched with a flat thread transmission, and the positioning pin 7-2 has threads only on the part that contacts the driving disk 7-4, when the second robotic arm 6 controls the driving rod 7-3 to rotate toward the inside of the heat exchange tube 16, the four positioning pins 7-2 on each fixed seat 7-5 will synchronously and slowly extend outward, and in the process of the positioning pins 7-2 extending outward, the driving rod 7-3 will continuously adjust its own position according to the distance from different positioning pins 7-2 to the inner wall of the heat exchange tube 16, ensuring that when the top pressure surfaces of the four positioning pins 7-2 on the fixed seat 7-5 all touch the inner hole wall of the heat exchange tube 16, the central axis of the positioning cylinder 7-1 and the driving rod 7-3 coincides with the central axis of the heat exchange tube 16, and the driving rod 7-3 no longer moves.

[0034] When the positioning device 7 reaches the above state, the position of the central axis of the positioning device 7 is fed back to the main controller 1. The main controller 1 determines the specific orientation of the outer wall of the heat exchange tube 16 at this time (outer diameter of the heat exchange tube 16 = wall thickness + extended distance of the positioning pin 7-2 + distance between the positioning pin 7-2 and the central axis of the driving rod 7-3), and then controls the wire feeding mechanism 12 to realize wire feeding, and the welding gun 8 performs vertical telescopic movement and circular movement parallel to the tube plate 17 around the positioning device 7 through the rotating shaft 9, thereby achieving precise welding.

[0035] When the welding of this heat exchange tube 16 is completed, the main controller 1 controls the movement of the first robot arm 13 and the second robot arm 6 through the lifting platform 4 and the main shaft 5, and controls the driving rod 7-3 to rotate in the opposite direction, thereby driving the driving disk 7-4 to rotate in the opposite direction. The four positioning pins 7-2 on each fixed seat 7-5 are synchronously contracted. After the contraction is completed, the positioning device 7 is pulled out from the heat exchange tube 16, and then the next heat exchange tube 16 is automatically welded. When all the heat exchange tubes 16 on this tube sheet 17 are welded, if the diameter of the heat exchange tube on the other tube sheet is different, the positioning device can be replaced to continue the automatic welding.

[0036] In summary, since the positioning device 7 of the present invention extends into the inner hole of the heat exchange tube 16 when in use, each positioning pin 7-2 presses against the inner hole wall of the heat exchange tube 16 closer to the inside, rather than the tube mouth, which can avoid the high-temperature area near the tube mouth and avoid the problem of the tube mouth being easily deformed and affecting the welding quality. In addition, three groups of positioning pins 7-2 are arranged at intervals along the axial direction to achieve multi-point pressing in the axial direction, ensuring that after the positioning pins 7-2 are extended into place, the central axis of the positioning cylinder 7-1 and the drive rod 7-3 coincide with the central axis of the heat exchange tube 16, thereby ensuring positioning accuracy and further ensuring that the axis of the heat exchange tube is coaxial with the rotation axis of the welding gun. At the same time, the positioning cylinder 7-1 is cylindrical, which reduces the space occupied by the external space of the heat exchange tube compared to the conical head in the prior art, which is beneficial for the welding gun 8 to avoid the positioning device 7, and further beneficial for the arrangement and installation of the welding gun 8 and the welding operation.

[0037] In other embodiments of the heat exchanger tube sheet welding equipment: the welding equipment body may not include a camera. In this case, the operator identifies the unwelded tube sheet holes through naked eye observation and controls the positioning device to extend into the corresponding heat exchange tube.

[0038] In other embodiments of the heat exchanger tube sheet welding equipment: the rotational power source may also be a hydraulic motor or a pneumatic motor.

[0039] In other embodiments of the heat exchanger tube sheet welding equipment: the driving rod and the output shaft of the rotary power source can also be fixed and no longer disassembled. Of course, the positioning cylinder and the welding equipment body can also be fixed and no longer disassembled. At this time, the positioning device can only position heat exchange tubes of one diameter, or heat exchange tubes with similar diameters.

[0040] In other embodiments of the heat exchanger tube sheet welding equipment: when the locating pin is composed of a locating pin body and an insulation pad and the surface of the insulation pad constitutes a top pressure surface, the top pressure surface can also be an arc-shaped surface formed by a part of a cylindrical surface. At this time, there is line contact between the top pressure surface of a single locating pin and the inner hole wall of the heat exchange tube.

[0041] In other embodiments of the heat exchanger tube sheet welding equipment: the locating pin can be composed only of the locating pin body, excluding the thermal insulation pad. At this time, the end face of the locating pin body directly constitutes the top pressure surface, and at this time the top pressure surface is an arc-shaped surface. Of course, the arc-shaped surface can be a spherical surface or a part of a cylindrical surface.

[0042] In other embodiments of the heat exchanger tube sheet welding equipment: regardless of whether the locating pin is composed of only the locating pin body or the locating pin body and the thermal insulation pad, the top pressure surface may not be an arc-shaped surface but a flat surface, except that in this case there is line contact between the top pressure surface and the inner hole wall of the heat exchange tube.

[0043] In other embodiments of the heat exchanger tube sheet welding equipment: the positioning member may not be a slender part such as a positioning pin, but a positioning block. In this case, the end face of the positioning block constitutes a top pressure surface, and the top pressure surface can be set as an arc surface.

[0044] In other embodiments of the heat exchanger tube sheet welding equipment: the number of drive disks, the number of fixing seats, and the number of positioning members all correspond one-to-one to the number of perforation groups, and can be set accordingly according to the number of perforation groups, and the number of positioning members in a group is also determined according to the number of perforations in a perforation group.

[0045] In other embodiments of the heat exchanger tube sheet welding equipment: a fixing seat may no longer be fixedly provided in the positioning cylinder, and the positioning piece may be guided by the through-holes on the positioning cylinder.

[0046] In other embodiments of the heat exchanger tube sheet welding equipment: when there is only one perforation group and only one drive disk and fixing seat, the drive rod may not pass through the drive disk, and the end of the drive rod may be directly welded and fixed at the center position of the end face of the drive disk.

[0047] In other embodiments of the heat exchanger tube sheet welding equipment: the rotation control structure may not be in the form of a drive rod and a rotational power source, but in the form of a gear structure + motor. For example, a gear structure is provided on the drive disk, a motor is fixedly provided in the positioning cylinder, a drive gear is installed at the output end of the motor, and the drive gear is engaged with the gear structure on the drive disk, thereby controlling the rotation of the drive disk.

[0048] In other embodiments of the heat exchanger tube sheet welding equipment: the driving mechanism may not be in the form of a driving disk + rotation control structure, but includes a driving rod with a wedge-shaped surface and a cylinder, a hydraulic cylinder or an electric push rod that is transmission-connected to the driving rod and can control the axial telescopic movement of the driving rod along the positioning tube. The positioning parts are arranged around the driving rod, and each positioning part is provided with an inclined surface that fits with the wedge-shaped surface on the driving rod. When the driving rod moves axially toward the positioning tube, the positioning part is squeezed by the cooperation of the wedge-shaped surface and the inclined surface so that the positioning part extends radially along the positioning tube and presses against the inner hole wall of the heat exchange tube to achieve positioning of the heat exchange tube. At the same time, an elastic part, such as a compression spring, is provided between the positioning part and the positioning tube. When the positioning part moves outward, the compression spring is squeezed to deform, so that when the driving rod moves in the opposite direction, the positioning parts can be reset.

[0049] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. The scope of patent protection of the present invention shall be based on the claims. Any equivalent structural changes made using the description and drawings of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A heat exchanger tube sheet welding device, comprising a welding device body and a positioning device arranged on the welding device body, characterized in that: The positioning device includes a positioning cylinder for extending into the inner hole of the heat exchange tube. At least one group of perforations is opened on the wall of the positioning cylinder. One group of perforations includes at least three perforations arranged at intervals along the circumference of the positioning cylinder. A positioning piece is provided in each perforation. One end of the positioning piece is located outside the positioning cylinder and is provided with a pressing surface for pressing the inner hole wall of the heat exchange tube. The other end of the positioning piece is located inside the positioning cylinder and is transmission-connected to a driving mechanism for driving the positioning piece to move radially along the positioning cylinder.

2. The heat exchanger tube sheet welding equipment according to claim 1, characterized in that: The driving mechanism includes a driving disc and a rotation control structure for controlling the rotation of the driving disc. The driving disc and the positioning member are matched through a plane thread transmission.

3. The heat exchanger tube sheet welding equipment according to claim 2, characterized in that: The rotation control structure includes a driving rod fixedly connected to the center of the driving disk and a rotation power source transmission-connected to the driving rod to control the rotation of the driving rod.

4. The heat exchanger tube sheet welding equipment according to claim 3, characterized in that: The driving rod passes through the driving disk, and at least two driving disks are fixed at intervals along the axial direction of the driving rod. There are at least two groups of perforation groups, and each group of perforation groups is arranged at intervals along the axial direction of the positioning cylinder and corresponds to the driving disk one by one.

5. The heat exchanger tube sheet welding equipment according to claim 4, characterized in that: A fixing seat is fixed in the positioning cylinder, and a guide groove extending radially along the positioning cylinder is provided on the fixing seat. One end of the positioning member located in the positioning cylinder is guided and slidably installed in the guide groove; at least two fixing seats are fixed at intervals along the axial direction of the positioning cylinder, and the fixing seats correspond to the driving disks one by one.

6. The heat exchanger tube sheet welding equipment according to any one of claims 1 to 3, characterized in that: A fixing seat is fixedly arranged in the positioning cylinder, and a guide groove extending radially along the positioning cylinder is arranged on the fixing seat. One end of the positioning piece located in the positioning cylinder is guided and slidably installed in the guide groove.

7. The heat exchanger tube sheet welding equipment according to any one of claims 1 to 5, characterized in that: The top pressing surface is an arc-shaped surface.

8. The heat exchanger tube sheet welding equipment according to any one of claims 1 to 5, characterized in that: The positioning piece comprises a positioning piece body and a heat insulating pad fixed to the end of the positioning piece body, and the surface of the heat insulating pad constitutes the top pressure surface.

9. The heat exchanger tube sheet welding equipment according to any one of claims 3 to 5, characterized in that: The rotary power source is fixedly arranged on the welding equipment body, the rotary power source and the driving rod are detachably connected through a coupling, and the positioning cylinder and the welding equipment body are detachably connected through bolts.

10. The heat exchanger tube sheet welding equipment according to any one of claims 1 to 5, characterized in that: The welding equipment body includes a camera for identifying unwelded tube sheet holes.

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