Plastic pipe hot air welding machine and control method thereof

Abstract

This invention relates to a hot air welding machine for plastic pipes and its control method, relating to the field of plastic pipe welding. The machine includes a control box, a hot air mechanism disposed in the control box for heating the plastic pipes to be connected, and a clamping mechanism for clamping the plastic pipes. The hot air mechanism includes a heating head for placing the connection portion of the plastic pipe, an air supply pipe connecting the heating head and the control box for providing an air source, and a heating pipe connected to the heating head for supplying heat to the heating head. The heating head has a placement groove for radially inserting the plastic pipe, and the inner wall of the placement groove has symmetrically arranged air outlets. The clamping mechanism includes a lifting cylinder and a clamping plate mounted on the lifting cylinder. The clamping plate has clamping components at both ends for respectively clamping two sections of plastic pipe. The lifting cylinder drives the clamping plate to rise and fall to place the two sections of plastic pipe, after heat shrink tubing application, into the placement groove. This application improves the operational efficiency when connecting plastic pipes.

Description

Technical Field

[0001] This invention relates to the field of plastic pipe welding, and in particular to a hot air welding machine for plastic pipes and its control method. Background Technology

[0002] Plastic pipes are widely used in various fields, and in practical use, they often need to be connected due to insufficient length.

[0003] Traditional plastic pipe splicing methods usually involve manual operation. The specific process is as follows: after aligning the two plastic pipe sections, heat shrink tubing is put on the splice joint, and then the heat shrink tubing is heated to shrink and tightly wrap the two plastic pipe sections, thereby achieving the connection.

[0004] The above steps usually require the use of a heat gun. Since the operator needs to hold the plastic tube to be connected with one hand and hold and operate the heat gun with the other hand, it is quite inconvenient. Summary of the Invention

[0005] To improve the operational efficiency of connecting plastic pipes using heat shrink tubing, this invention provides a hot air welding machine for plastic pipes and its control method.

[0006] In a first aspect, the present invention provides a hot air welding machine for plastic pipes, which adopts the following technical solution:

[0007] A hot air welding machine for plastic pipes includes a control box, a hot air mechanism disposed in the control box and used to blow air and heat the plastic pipes to be connected, and a clamping mechanism for clamping the plastic pipes.

[0008] The hot air mechanism includes a heating head for placing the connection part of the plastic tube, an air supply pipe connecting the heating head and the control box and for providing an air source, and a heating pipe connected to the heating head and for supplying heat to the heating head; the heating head has a placement groove for radially inserting the plastic tube and the inner wall of the placement groove has symmetrical air outlets.

[0009] The clamping mechanism includes a lifting cylinder and a clamping plate installed on the lifting cylinder; the clamping plate has clamping components at both ends for clamping two plastic tubes respectively; the lifting cylinder drives the clamping plate to rise and fall to place the two plastic tubes with heat shrink tubing sleeves into the placement slot.

[0010] By adopting the above technical solution, two plastic tubes are clamped on the clamping assembly, and then heat shrink tubing is fitted at the joint between them. After completing the above steps, the lifting cylinder automatically drives the plastic tube to descend into the placement slot of the heating head. The air outlet in the placement slot can blow hot air onto the heat shrink tubing, quickly heating and shrinking it so that the heat shrink tubing tightly wraps around the joint of the two plastic tubes, thereby completing the connection of the two plastic tubes. The above steps do not require manual handling of both the hot air gun and the plastic tube at the same time, resulting in high work efficiency.

[0011] Optionally, the clamping assembly includes an upper clamping plate and a lower clamping plate, the lower clamping plate having a fixing rod at its top, and the upper clamping plate being sleeved on the fixing rod; the fixing rod is provided with a compression spring for pressing the upper clamping plate against the lower clamping plate.

[0012] Optionally, the upper clamp and the lower clamp are bent in a direction away from each other to form a perforation for the plastic tube to pass through; the top of the clamping plate is rotatably provided with a cover plate that covers the top opening of the placement slot, and the cover plate is concave upward with an arc surface; the air outlet includes a first air outlet and a second air outlet, and the openings of the first air outlet and the second air outlet can be adjusted up and down by rotation.

[0013] By adopting the above technical solution, when the cover plate closes the top opening of the placement groove, the placement groove forms a hole with openings on only two sides. When the plastic tube is placed into the placement groove, the up and down orientation of the air outlet is adjusted, and the air blown out by the air outlet can form an axially rotating vortex in the placement groove, thereby uniformly heating the heat shrink tube around its circumference, and the heat shrink tube in the entire placement groove can be heated and shrunk.

[0014] Secondly, this application provides a control method for a hot air welding machine for plastic pipes, employing the following technical solution:

[0015] A control method for a hot air welding machine for plastic pipes, applied to a hot air welding machine for plastic pipes, comprising:

[0016] Acquire images of the clamping position;

[0017] Determine from the clamping position image whether a plastic tube to be connected is inserted;

[0018] When a plastic tube to be connected is inserted, the preset heat shrink tubing is controlled to enter the preset clamping position;

[0019] Insert the two plastic tubes to be connected from both ends of the heat shrink tubing and confirm whether the connection is successful.

[0020] When the two plastic pipes to be connected are successfully joined, an image of the plastic pipe installation is captured.

[0021] The plastic pipe type is determined by image recognition of the plastic pipe to be connected from the plastic pipe installation image. The plastic pipe type includes segmented plastic pipe and continuous plastic pipe.

[0022] For segmented plastic tubes, a preset rotary connection method is used to control the air outlet to blow hot air onto the plastic tube and make the plastic tube rotate in the placement groove;

[0023] For continuous plastic tubes, the air outlet is controlled to blow hot air and circulate and heat the tube within the placement slot using a preset circulating hot air method.

[0024] By adopting the above technical solution, the system can identify the type of plastic tube placed in the placement slot, determine whether the plastic tube is segmented or connected, and effectively process the plastic tube according to its type, so that the heat shrink tubing can evenly connect the joints of the two plastic tube segments.

[0025] Optional methods for confirming successful connection of plastic pipes include:

[0026] Extract heat shrink tubing features from the clamping position image, and determine the heat shrink tubing feature length based on the heat shrink tubing features;

[0027] The position of the middle part of the heat shrink tubing is determined based on its characteristic length.

[0028] The clamping arm, which is pre-set on the cover plate, clamps the middle part of the heat shrink tubing and applies force to the middle part of the heat shrink tubing with a preset flattening force.

[0029] The insertion distance of the plastic tube is determined based on the characteristic length of the heat shrink tubing and the midpoint position of the heat shrink tubing.

[0030] Insert the plastic tube into both ends of the heat shrink tubing according to the specified insertion distance, and collect the pressure on the clamping arm;

[0031] When the pressure reaches the preset compressive force, the clamping arm is controlled to release the heat shrink tubing.

[0032] Optional, also includes:

[0033] Based on the position of the middle part of the heat shrink tubing and the preset control distance, the positions of the control groups located on both sides of the middle part of the heat shrink tubing are determined.

[0034] The clamping arm is controlled to clamp the middle position of the heat shrink tubing and the control group position with a preset detection force, and the pressure surface area of ​​the middle position and the pressure surface area of ​​the control group are collected.

[0035] When the area of ​​the central pressure-bearing surface is inconsistent with the area of ​​the control group pressure-bearing surface, the difference between the area of ​​the central pressure-bearing surface and the area of ​​the control group pressure-bearing surface is calculated and defined as the misalignment area;

[0036] The adjustment distance is determined based on the misalignment area and the preset plastic pipe diameter.

[0037] The plastic tube is pulled out to both sides according to the adjusted distance.

[0038] Optionally, the rotational connection method includes:

[0039] Determine the forward heating position and the rotation tangent point position based on the plastic tube installation image;

[0040] The first air outlet is controlled to face the forward heating position, and the second air outlet is controlled to face the rotation tangent position;

[0041] The second air outlet is controlled to blow air at a preset initial wind speed, and the initial wind speed is increased by a preset wind speed increment to reach a preset maximum wind speed. The rotation state of the plastic tube is identified based on the plastic tube installation image.

[0042] When the rotation state of the plastic tube is consistent with the preset uniform rotation state, the maximum wind speed is reduced by a preset wind speed reduction to bring the plastic tube to a preset critical rotation state, the rotation speed of the plastic tube is collected, and the heating temperature is matched according to the rotation speed of the plastic tube.

[0043] The first air outlet is controlled to blow air onto the plastic tube at the heating temperature to uniformly shrink the heat shrink tube circumferentially.

[0044] When the rotation state of the plastic tube is inconsistent with the uniform rotation state, the first air outlet is controlled to face the rotation tangent position and blow air at the maximum wind speed.

[0045] Simultaneously, the maximum wind speed of the first air outlet and the second air outlet is adjusted, and the maximum wind speed is reduced by the wind speed reduction to bring the plastic tube to the critical rotation state, and the rotation speed of the plastic tube is collected.

[0046] The heating temperature is matched according to the rotation speed of the plastic tube, and the first and second air outlets are controlled to blow air at the heating temperature simultaneously.

[0047] By adopting the above technical solution, when both plastic tubes are segmented, the plastic tubes are lightweight, and the air blown out by the air outlet can drive the plastic tubes to rotate during the welding process, so that the heat shrink tubing can be heated evenly in the circumference and the joint of the plastic tubes can be tightly connected.

[0048] Optional, also includes:

[0049] Determine the feature length of the heat shrink tubing from the clamping position image;

[0050] The lateral displacement speed of the plastic tube is matched according to the rotational speed of the plastic tube.

[0051] The displacement time is determined based on the characteristic length of the heat shrink tubing and the lateral displacement velocity of the plastic tube.

[0052] The displacement time is defined as the periodic time. At the end of each periodic time, the orientation of the first air outlet and the orientation of the second air outlet are swapped, and the number of periodic swaps is recorded.

[0053] The machine stops when the number of cycle swaps reaches the preset limit.

[0054] Optionally, the surrounding hot air method includes:

[0055] Determine the feature length of the heat shrink tubing from the clamping position image;

[0056] The extension length is determined based on the characteristic length of the heat shrink tubing and the preset axial length of the placement groove;

[0057] The extension plate, which is pre-set in the heating head and the cover plate, is extended to lengthen the placement groove, and the extension plate is controlled to cover one section of the placement groove.

[0058] Determine the rotary heating position based on the plastic tube installation image;

[0059] The first and second air outlets are controlled to blow air towards the symmetrical rotating heating positions to form a rotating airflow within the placement slot.

[0060] By adopting the above technical solution, when the two plastic tubes are continuous, since the plastic tubes cannot rotate, by extending the placement groove, the heat shrink tubing can be completely placed in the placement groove. Then, by adjusting the direction of the air outlet, the air blown out by the air outlet can generate axial rotation wind in the placement groove. The wind can wrap and heat the entire heat shrink tubing, so that the heat shrink tubing can be heated evenly and shrink to connect the two plastic tubes.

[0061] Optionally, the top of the cover plate has a preparation cavity for placing the heat shrink tubing, the preparation cavity having a discharge channel communicating with the placement slot, and further includes:

[0062] The first and second air outlets are controlled to blow air at a preset initial wind speed;

[0063] The material feeding channel and the double-sided baffles pre-installed in the material feeding channel are opened to preheat and shrink the middle part of the heat shrink tube placed in the preparation cavity, and the temperature of the placement groove is collected.

[0064] When the temperature of the placement tank reaches the preset starting temperature, the feeding channel is closed.

[0065] In summary, this application includes at least one of the following beneficial technical effects:

[0066] By clamping two plastic tubes onto the clamping assembly, and then fitting heat shrink tubing at the joint between them, the lifting cylinder automatically drives the plastic tubes down into the placement slot of the heating head. The air outlet in the placement slot blows hot air onto the heat shrink tubing, quickly heating and shrinking it so that the heat shrink tubing tightly wraps around the joint between the two plastic tubes, thus completing the connection of the two plastic tubes. The above steps do not require manual handling of both the hot air gun and the plastic tubes, resulting in high work efficiency.

[0067] When both plastic tubes are segmented, because the plastic tubes are relatively light, the air blown out by the air outlet can drive the plastic tubes to rotate during the welding process, so that the heat shrink tubing can be heated evenly in the circumference and tightly connect the joints of the plastic tubes.

[0068] When the two plastic tubes are continuous, since the plastic tubes cannot rotate, the placement groove is extended so that the heat shrink tubing can be completely placed in the placement groove. Then, the direction of the air outlet is adjusted so that the air blown out by the air outlet can generate axial rotation in the placement groove. The air can wrap and heat the entire heat shrink tubing, so that the heat shrink tubing can be heated evenly and shrink to connect the two plastic tubes. Attached Figure Description

[0069] Figure 1 This is a schematic diagram of the overall structure of Embodiment 1 of the present invention;

[0070] Figure 2 This is a schematic diagram of the heating head according to Embodiment 1 of the present invention;

[0071] Figure 3 This is a schematic diagram of the clamping mechanism according to Embodiment 1 of the present invention;

[0072] Figure 4 This is a schematic diagram of the hot air mechanism and clamping mechanism in Embodiment 2 of the present invention;

[0073] Figure 5 This is a schematic diagram of the heating head of Embodiment 2 of the present invention;

[0074] Figure 6 This is a schematic diagram of the clamping mechanism of Embodiment 2 of the present invention.

[0075] The parts referred to by the numbers in the above attached figures are as follows: 1. Control box; 2. Hot air mechanism; 21. Heating head; 211. Placement slot; 212. Air outlet; 2121. First air outlet; 2122. Second air outlet; 22. Air supply pipe; 23. Heating pipe; 3. Clamping mechanism; 31. Lifting cylinder; 32. Clamping plate; 33. Clamping assembly; 331. Upper clamping plate; 332. Lower clamping plate; 333. Fixing rod; 334. Compression spring; 335. Perforation; 34. Cover plate; 341. Arc surface; 342. Preparation chamber; 343. Material unloading channel; 4. Extension plate. Detailed Implementation

[0076] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0077] This application discloses a hot air welding machine for plastic pipes. Example 1:

[0078] Reference Figure 1 A hot air welding machine for plastic pipes includes a control box 1, a hot air mechanism 2, and a clamping mechanism 3. The control box 1, as a control unit, controls the entire welding process of the plastic pipes and provides both air and heat sources to generate hot air. The hot air mechanism 2 and the clamping mechanism 3 are both mounted on the control box 1. The clamping mechanism 3 clamps two sections of plastic pipe and facilitates the application of heat shrink tubing at their joint. The hot air mechanism 2 heats the heat shrink tubing applied at the joint by blowing air, causing it to shrink and tightly wrap around the two sections of plastic pipe.

[0079] Reference Figure 1 and Figure 2 The hot air mechanism 2 includes a heating head 21, an air supply pipe 22, and a heating pipe 23.

[0080] The air supply duct 22 is a cylindrical plastic pipe that is connected to the control box 1. The air supply duct 22 is hollow inside, allowing air generated by the fan inside the control box 1 to pass through.

[0081] The heating head 21 is made of metal and is easy to conduct heat. The heating head 21 has a placement groove 211 for inserting a plastic tube vertically, with both sides of the placement groove 211 extending through it. The heating head 21 has air outlets 212 symmetrically arranged on the inner wall of the placement groove 211. The air outlets 212 are connected to the inner cavity of the air supply pipe 22 and are used to supply air to blow out from the air outlets 212.

[0082] The heating pipe 23 connects the control box 1 and the heating head 21. The control box 1 supplies power to the heating head 21, which in turn heats the resistance wire inside the heating head 21, thus giving the air blown out from the air outlet 212 heat.

[0083] Reference Figure 1 and Figure 3 The clamping mechanism 3 includes a lifting cylinder 31 and a clamping plate 32.

[0084] The lifting cylinder 31 is mounted on the base platform of the control box 1, and the push rod of the lifting cylinder 31 is vertically upward so that it can be vertically lifted and lowered.

[0085] The clamping plate 32 is mounted on the top of the push rod of the lifting cylinder 31. The clamping plate 32 is C-shaped, with both ends facing the control box 1. Each end of the clamping plate 32 is provided with a clamping assembly 33, which is used to clamp a section of plastic tube. The area between the two ends of the clamping plate 32 is the clamping position. When the clamping assembly 33 clamps the plastic tube, the joint of the two sections of plastic tube is located in the clamping position. Simultaneously, the clamping position and the placement groove 211 are located in the same vertical plane.

[0086] The clamping assembly 33 includes an upper clamping piece 331 and a lower clamping piece 332. The lower clamping piece 332 is integrally formed with the clamping plate 32, and a fixing rod 333 is vertically mounted on the top of the lower clamping piece 332. The upper clamping piece 331 is sleeved on the fixing rod 333, and a compression spring 334 is sleeved on the fixing rod 333. The compression spring 334 always presses the upper clamping piece 331 tightly against the top of the lower clamping piece 332. The lower clamping piece 332 and the upper clamping piece 331 are used to clamp the plastic tube.

[0087] Combination Figures 1 to 3 After installing the two plastic tubes onto the clamping assembly 33, heat shrink tubing is fitted at the joint of the two plastic tubes. Then, the lifting cylinder 31 drives the clamping plate 32 to descend, and the clamping position falls into the placement groove 211. The joint of the two plastic tubes, i.e. the heat shrink tubing position, enters the placement groove 211. At this time, the heating head 21 can blow air onto the plastic tubes through the air outlet 212. Example 2:

[0088] The plastic pipe hot air welding machine of Example 2 is the same as that of Example 1 except that the air outlet 212, the clamping component 33 and the cover plate 34 are different. The rest of the structure is the same and will not be described in detail here.

[0089] Combination Figures 4 to 6 In this embodiment, the upper clamping piece 331 and the lower clamping piece 332 are bent in a direction away from each other to form a through hole 335 for the plastic tube to pass through. A cover plate 34 is rotatably provided on the top of the clamping plate 32. The bottom of the cover plate 34 is concave upward to form an arc surface 341, and the arc surface 341 is above the clamping position.

[0090] After the clamping assembly 33 clamps the plastic tube, the lifting cylinder 31 drives the plastic tube into the placement groove 211. At this time, the cover plate 34 can abut against the top opening of the placement groove 211 and cover the top opening, so that the placement groove 211 forms a complete hole with only two openings.

[0091] Furthermore, the air outlet 212 on the inner wall of the heating head 21 includes a first air outlet 2121 and a second air outlet 2122, which are symmetrically arranged and located on one side of the inner wall of the heating head 21. In this embodiment, the opening of the air outlet 212 is arranged to rotate up and down on the inner wall of the heating head 21, so that the air outlet direction of the air outlet 212 can be adjusted.

[0092] By tilting the first air outlet 2121 and the second air outlet 2122 to blow air, the air generated can rotate axially within the placement slot 211.

[0093] Based on the same inventive concept, embodiments of the present invention provide a control method for a hot air welding machine for plastic pipes.

[0094] A control method for a hot air welding machine for plastic pipes includes the following steps:

[0095] Step S1: Acquire the clamping position image.

[0096] The clamping position image refers to an image captured by a camera at the clamping position between the two clamping components 33. The camera is fixedly mounted on the control box 1 and captures images of the clamping position in real time. When the plastic tube is installed at the clamping position, the plastic tube can be identified in the clamping position image.

[0097] Step S2: Determine from the clamping position image whether a plastic tube to be connected is inserted.

[0098] By analyzing the image of the clamping position, the presence of plastic tube features in the image is determined, thereby confirming whether a plastic tube has been installed on the clamping mechanism 3. Only after the plastic tube is installed can the system proceed to the next step.

[0099] Step S3: When the plastic tube to be connected is inserted, control the preset heat shrink tubing to enter the preset clamping position.

[0100] If no plastic tube is inserted, the system remains in standby mode, and the camera continues to capture and identify the clamping position in real time until a plastic tube is inserted.

[0101] After the plastic tube is inserted, the system will unload the heat shrink tubing into the clamping position so that the heat shrink tubing can be fitted onto the joint when the two plastic tubes are joined.

[0102] In this embodiment, a preparatory cavity 342 is provided on the cover plate 34, and the heat shrink tubing is pre-cut and placed in the preparatory cavity 342. A feeding channel 343 is provided between the preparatory cavity 342 and the clamping position. When the heat shrink tubing is needed, the system opens the feeding channel 343 to allow the heat shrink tubing to enter the clamping position through the feeding channel 343. The clamping position is flipped to provide a support plate for supporting the heat shrink tubing. After the heat shrink tubing comes down from the feeding channel 343, it is placed on the support plate, at which time the heat shrink tubing can mate with the plastic tube. After mating, the support plate retracts.

[0103] Step S4: Insert the two plastic tubes to be connected from both ends of the heat shrink tubing and confirm whether the connection is successful.

[0104] Once the system detects that the heat shrink tubing is in the clamping position, it then controls the two plastic tubing segments to be inserted from both ends of the heat shrink tubing. During insertion, the system identifies and confirms the alignment of the plastic tubing segments to ensure that they are properly aligned end-to-end. The specific identification and confirmation method will not be detailed here but will be described in detail in subsequent embodiments.

[0105] Step S5: When the two plastic pipes to be connected are successfully joined, capture an image of the plastic pipe installation.

[0106] The plastic tube installation image refers to the overall image captured by the camera after the heat shrink tubing has been installed. At the time the plastic tube installation image is captured, the lifting cylinder 31 has not yet lowered the plastic tube into the placement slot 211.

[0107] Step S6: Perform image recognition on the plastic pipes to be connected from the plastic pipe installation image to determine the type of plastic pipe. The plastic pipe types include segmented plastic pipes and continuous plastic pipes.

[0108] The type of plastic pipe refers to the complete state of the two plastic pipe segments to be connected. A segmented plastic pipe refers to two plastic pipe segments that are each only one section long. A connecting plastic pipe refers to two plastic pipe segments that are both relatively long and are not yet complete. The difference between segmented and continuous plastic pipes is that segmented and continuous plastic pipes can rotate when circumferential force is applied.

[0109] The type of plastic pipe can be identified and analyzed from the plastic pipe installation image. The type is determined by analyzing the length of the two plastic pipe sections extending to both sides.

[0110] Step S60: For the segmented plastic tube, the air outlet 212 is controlled to blow hot air onto the plastic tube and rotate the plastic tube in the placement groove 211 using a preset rotation connection method.

[0111] For segmented plastic tubes, since they can be rotated by blowing air when clamped in the perforation 335 of the clamping component 33, a rotational connection method is used to connect the two segments of plastic tubes. The specific method of the rotational connection method will not be described in detail here, but will be described in detail in subsequent embodiments.

[0112] Step S61: For the continuous plastic tube, the air outlet 212 is controlled to blow hot air and circulate and heat it in the placement groove 211 using a preset hot air circulation method.

[0113] For continuous plastic tubes, due to their long length and heavy weight, the plastic tubes cannot be rotated. Therefore, the system uses a surrounding hot air method to control the air outlet 212 to heat and connect the plastic tubes. The specific method of the surrounding hot air method will not be described in detail here, but will be introduced in detail in subsequent embodiments.

[0114] The method for confirming a successful connection of plastic pipes includes the following steps:

[0115] Step S40: Extract the heat shrink tubing features from the clamping position image, and determine the heat shrink tubing feature length based on the heat shrink tubing features.

[0116] The characteristic of heat shrink tubing is that it is heat shrink tubing. After the plastic tube is inserted into the heat shrink tubing, the camera captures an image of the clamping position again. The heat shrink tubing can be identified from the clamping position image, and by analyzing the heat shrink tubing in the image, its length in the image can be determined. Combined with the image ratio of the captured image pre-set by the camera, the actual length of the heat shrink tubing can be determined.

[0117] Step S400: Determine the midpoint position of the heat shrink tubing based on its characteristic length.

[0118] The middle position of heat shrink tubing refers to the exact midpoint along its length. When determining the characteristic length of heat shrink tubing, the middle position is the location on the tubing that is half the characteristic length of the tubing from both ends.

[0119] Step S401: Control the clamping arm preset on the cover plate 34 to clamp the middle position of the heat shrink tube, and apply force to the middle position of the heat shrink tube with a preset clamping force.

[0120] Once the center position of the heat shrink tubing is determined, the system controls the clamping arm to apply clamping force to the center position of the heat shrink tubing. In this embodiment, the clamping mechanism 3 integrates a clamping arm, which clamps the center position of the heat shrink tubing as the plastic tube is inserted from both ends.

[0121] To ensure that the plastic tube is inserted at a consistent distance from both ends of the heat shrink tubing, a clamping arm is used to hold the tube in the middle to restrict the insertion process.

[0122] The clamping force is a parameter that technicians pre-set for the clamping arm. When the clamping arm clamps the heat shrink tubing with the clamping force, it can flatten the heat shrink tubing.

[0123] Step S402: Determine the plastic tube insertion distance based on the characteristic length of the heat shrink tubing and the midpoint position of the heat shrink tubing.

[0124] The insertion distance of the plastic tube refers to the insertion distance of the plastic tube to be connected when it is inserted from the end of the heat shrink tubing. Because the middle of the heat shrink tubing is held by the clamping arm, the insertion distance of the plastic tube is half the characteristic length of the heat shrink tubing.

[0125] Step S403: Insert the plastic tube into both ends of the heat shrink tubing according to the specified insertion distance, and collect the pressure of the clamping arm.

[0126] When the plastic tube is inserted into the middle of the heat shrink tubing, it exerts pressure on the clamping arm through the tubing. This pressure is the pressure exerted on the clamping arm by the plastic tube. The clamping arm is equipped with a pressure sensor, which allows the system to determine the magnitude of the pressure.

[0127] Step S404: When the pressure reaches the preset compressive force, control the clamping arm to release the heat shrink tubing.

[0128] The compressive force is a critical reference value set by the technician for the pressure exerted by the plastic tube on the clamping arm, which will not be elaborated here. When the pressure reaches the compressive force, it indicates that the plastic tube has been inserted to the middle position of the heat shrink tubing.

[0129] Once both ends of the plastic tube have been inserted into the middle of the heat shrink tubing, remove the clamping arms. At this point, the two plastic tubes will be in contact inside the heat shrink tubing.

[0130] The method for confirming a successful connection of plastic pipes also includes the following steps:

[0131] Step S41: Based on the position of the middle part of the heat shrink tubing and the preset control distance, determine the positions of the control groups located on both sides of the middle part of the heat shrink tubing.

[0132] The reference distance is a distance pre-set by the technician between the heat shrink tubing and the center position. Even if the plastic tubing is inserted incorrectly, it will not exceed the reference distance, which facilitates data collection by the clamping arm. This will not be elaborated further here.

[0133] The control group position refers to a point on the heat shrink tubing at a distance equal to the control distance from the center of the tubing; this position contains only a single plastic tube. There are two control group positions, symmetrically located on either side of the center of the heat shrink tubing.

[0134] Once the position of the center of the heat shrink tubing is determined, the control group position is determined by extending the control distance to both sides.

[0135] Step S410: Control the clamping arm to clamp the middle position of the heat shrink tubing and the control group position with a preset detection force, and collect the pressure surface area of ​​the middle position and the pressure surface area of ​​the control group.

[0136] In this embodiment, by using a clamping arm to clamp the middle position of the heat shrink tubing and the control group position, the difference in the pressure surface at the two positions is compared to determine whether the plastic tubing has been successfully connected.

[0137] The testing force refers to the clamping force set by the technicians for clamping the heat shrink tubing at the middle position and the control group position. Using the testing force will not easily damage the plastic tube inside the heat shrink tubing, which will not be elaborated here.

[0138] The area of ​​the pressure-bearing surface in the middle refers to the contact area between the clamping arm and the surface of the heat shrink tubing when the clamping arm holds the tubing at the middle position. The area of ​​the pressure-bearing surface in the control group refers to the contact area between the clamping arm and the surface of the heat shrink tubing when the clamping arm holds the tubing at the control group position. After the clamping arm clamps and releases the tubing at the middle position and the control group position, the contact surface is in a deformed state for a period of time. The corresponding area is determined by photographing and analyzing the contact surface in the deformed state.

[0139] Step S411: When the area of ​​the central pressure-bearing surface is inconsistent with the area of ​​the control group pressure-bearing surface, calculate the difference between the area of ​​the central pressure-bearing surface and the area of ​​the control group pressure-bearing surface, and define it as the misalignment area.

[0140] Under normal circumstances, if the two plastic tubes are properly joined, the area of ​​the middle pressure surface collected after clamping by the clamping arm should be consistent with the area of ​​the pressure surface of the control group, that is, both are the projected area of ​​one plastic tube.

[0141] When the two plastic tubes are inserted in a misaligned manner, the area of ​​the pressure-bearing surface in the middle will increase due to the misalignment. At this point, the area of ​​the pressure-bearing surface in the middle will differ from that of the control group. The misaligned area refers to the additional area when the two plastic tubes are inserted in a misaligned manner compared to when they are normally joined. The misaligned area is the difference between the area of ​​the pressure-bearing surface in the middle and the area of ​​the pressure-bearing surface in the control group.

[0142] Step S412: Determine the adjustment distance based on the misalignment area and the preset plastic pipe diameter value.

[0143] The diameter of the plastic pipe is a basic parameter of the plastic pipe to be connected, which will not be elaborated here.

[0144] Since the misalignment area is the projected area of ​​the extra plastic tube when two plastic tubes intersect, and the projected area is the product of the plastic tube diameter and the length of the misaligned plastic tube, the adjustment distance is the length of the misaligned plastic tube. The adjustment distance is also the distance the plastic tube is pulled out from the end of the heat shrink tubing when adjusting the plastic tube. Therefore, the adjustment distance can be obtained by calculating the quotient value based on the misalignment area and the plastic tube diameter.

[0145] Step S413: Control the plastic tube to be pulled out to both sides according to the adjusted distance.

[0146] Once the adjustment distance is determined, the system uses the adjustment distance control to pull the plastic tube out from both ends of the heat shrink tubing, ensuring that the two plastic tubes are not misaligned and can be properly connected.

[0147] The rotational connection method includes the following steps:

[0148] Step S600: Determine the forward heating position and the rotation tangent position based on the plastic tube installation image.

[0149] The forward heating position refers to the point where the surface of the heat shrink tubing is directly opposite the air blown out of the air outlet 212. The rotation tangent point position refers to the point where the surface of the heat shrink tubing is tangent to the air blown out of the air outlet 212.

[0150] By analyzing the images of the plastic tube installation, the characteristic positions of the exhaust nozzle 212 and the heat shrink tubing are determined. The positions of the two are then compared to determine the forward heating position and the rotation tangent point position.

[0151] In this embodiment, blowing air onto the forward heating position causes the heat shrink tubing to shrink due to heat. Blowing air onto the rotation tangent position causes the heat shrink tubing to rotate and shrink due to heat, but the shrinkage speed is slower due to the smaller heated area.

[0152] Step S601: Control the first air outlet 2121 to face the positive heating position, and control the second air outlet 2122 to face the rotation tangent position.

[0153] In this embodiment, the first air outlet 2121 is first oriented toward the forward heating position, and the second air outlet 2122 is rotated toward the rotation tangent position, so that the plastic tube and heat shrink tubing can shrink and rotate synchronously when driven by one air outlet 212.

[0154] Step S602: Control the second air outlet 2122 to blow air with a preset initial wind speed, and increase the initial wind speed with a preset wind speed increment to reach a preset maximum wind speed, and identify the rotation state of the plastic tube according to the plastic tube installation image.

[0155] The initial wind speed is the initial blowing speed of the air outlet 212 when the equipment is started, as set by the technicians, and will not be elaborated here.

[0156] The wind speed increment is the increment that the initial wind speed gradually increases per unit time, which is preset by the technicians, and will not be elaborated here.

[0157] The air outlet 212 initially blows air at a lower speed, then gradually increases the initial air speed with incremental speed increases, finally reaching the maximum air speed. This is to avoid adverse effects on the heat shrink tubing and plastic tubing due to a high initial air speed. The maximum air speed is the maximum speed of the air blown out by the air outlet 212 as set by the technicians, and will not be elaborated here.

[0158] The rotation state of the plastic tube refers to its real-time state under the airflow from the air outlet 212, whether it is stationary or rotating. This rotation state can be determined by analyzing the installation image of the plastic tube. By determining the rotation state of the plastic tube at maximum wind speed, it can be determined whether the wind speed of the air outlet 212 needs to be adjusted.

[0159] In this embodiment, the first air outlet 2121 and the second air outlet 2122 are internally connected, and their wind speed and temperature are the same. The difference is that their angles can be different.

[0160] Step S603: When the rotation state of the plastic tube is consistent with the preset uniform rotation state, the maximum wind speed is reduced by a preset wind speed reduction to bring the plastic tube to a preset critical rotation state, the rotation speed of the plastic tube is collected, and the heating temperature is matched according to the rotation speed of the plastic tube.

[0161] Uniform rotation is one of the states of rotation of a plastic tube, meaning that the plastic tube is in the process of rotation and is not stationary.

[0162] When the rotational state of the plastic tube at maximum wind speed is the same as that at a constant speed, it indicates that blowing air from only one outlet 212 towards the rotation tangent point is sufficient to drive the plastic tube to rotate, and the plastic tube can still rotate even if the wind speed of outlet 212 does not reach the maximum wind speed. In this case, in order to prevent the rotational speed of the plastic tube from being too fast and to ensure that the hot air blown from the first outlet 2121 can evenly heat the heat shrink tubing, the wind speed of outlet 212 needs to be reduced so that the plastic tube is in a critical rotational state. The critical rotational state refers to the state in which the plastic tube just begins to rotate under the action of wind force, at which point the air blown from outlet 212 is relatively small. The wind speed reduction is the amount of reduction in maximum wind speed per unit time set by the technicians, and will not be elaborated here.

[0163] The rotational speed of a plastic pipe refers to its rotational speed when it is at a critical point of rotation. The rotational speed is determined by taking images of the installed plastic pipe at intervals within a unit of time using a camera, and then analyzing these images.

[0164] The heating temperature is the temperature value of the air blown out by the first air outlet 2121. In this embodiment, the heating temperature is directly proportional to the rotation speed of the plastic tube; the lower the rotation speed of the plastic tube, the lower the heating temperature.

[0165] When hot air heats heat shrink tubing, if the tubing rotates at a low speed while the hot air temperature is high, the tubing is prone to wrinkles due to shrinking too quickly. Therefore, the heating temperature is directly proportional to the rotation speed of the plastic tubing.

[0166] Step S6030: Control the first air outlet 2121 to blow air onto the plastic tube at the heating temperature to uniformly shrink the heat shrink tube circumferentially.

[0167] After determining the orientation parameters, temperature parameters, and wind speed parameters of the first air outlet 2121 and the second air outlet 2122, the heat shrink tubing at the joint of the plastic tube is heated according to the obtained parameters so that it is evenly wrapped around the joint of the plastic tube.

[0168] Step S604: When the rotation state of the plastic tube is inconsistent with the uniform rotation state, control the first air outlet 2121 to face the rotation tangent position and blow air at the maximum wind speed.

[0169] If the rotational state of the plastic tube is inconsistent with its uniform rotational state at maximum wind speed, it indicates that when only one second air outlet 2122 blows air onto the rotational tangent point of the heat shrink tubing, even with maximum wind speed, the plastic tube cannot be driven to rotate. In this case, both air outlets 212 need to blow air onto the rotational tangent point of the heat shrink tubing simultaneously, so that the plastic tube receives double the cumulative driving force from both outlets 212. Therefore, the system directs the first air outlet 2121 towards the rotational tangent point and blows air at maximum wind speed. In this embodiment, the rotational tangent point towards which the first air outlet 2121 faces is symmetrical to the rotational tangent point towards which the second air outlet 2122 faces on the surface of the heat shrink tubing.

[0170] Step S6040: Simultaneously adjust the maximum wind speed of the first air outlet 2121 and the second air outlet 2122, reduce the maximum wind speed by the wind speed reduction to bring the plastic tube to the critical rotation state, and collect the rotation speed of the plastic tube.

[0171] Similar to step S603, the maximum wind speed of the air outlet 212 is reduced so that the plastic tube rotates at a critical state. Then, the camera takes pictures of the plastic tube installation at intervals within a unit time, and the rotation speed of the plastic tube is determined by image analysis of the plastic tube in multiple plastic tube installation pictures.

[0172] Step S6041: Match the heating temperature according to the rotation speed of the plastic tube, and control the first air outlet 2121 and the second air outlet 2122 to blow air at the heating temperature simultaneously.

[0173] Similar to steps S603 and S6030, after determining the orientation parameters, temperature parameters, and wind speed parameters of the first air outlet 2121 and the second air outlet 2122, the heat shrink tubing at the joint of the plastic tube is heated according to the obtained parameters so that it is evenly wrapped around the joint of the plastic tube.

[0174] The rotational connection method also includes the following steps:

[0175] Step S605: Determine the feature length of the heat shrink tubing from the clamping position image.

[0176] The characteristic length of heat shrink tubing refers to the length of the heat shrink tubing fitted at the joint of two plastic tubing segments. This characteristic length can be obtained through image analysis of the heat shrink tubing in the clamping position image.

[0177] Step S606: Match the lateral displacement speed of the plastic tube to the rotation speed of the plastic tube.

[0178] The lateral displacement speed of the plastic tube refers to the speed at which the plastic tube moves horizontally under the blowing force of the air outlet 212. The lateral displacement speed of the plastic tube is directly proportional to the rotational speed of the plastic tube; the faster the rotational speed of the plastic tube, the faster the lateral displacement speed.

[0179] In this embodiment, after the plastic tube is installed in the through hole 335 of the clamping assembly 33, when the plastic tube rotates, it can move horizontally synchronously within the through hole 335, the principle of which is the same as that of a threaded engagement. A threaded sleeve is provided inside the through hole 335, and the threaded sleeve engages with the through hole 335. The plastic tube passes through the threaded sleeve. When the plastic tube rotates, the threaded sleeve rotates synchronously, thus moving horizontally synchronously under the threaded engagement.

[0180] Step S607: Determine the displacement time based on the characteristic length of the heat shrink tubing and the lateral displacement speed of the plastic tube.

[0181] Since the heating head 21 has a fixed length, the air outlet 212 can only heat and shrink a small section of the heat shrink tubing at a time. Furthermore, because the plastic tubing can move horizontally when the air outlet 212 blows air onto it, the air outlet 212 can heat the entire section of heat shrink tubing after a period of time; this period is called the displacement time. The displacement time is the quotient of the characteristic length of the heat shrink tubing and the lateral displacement velocity of the plastic tubing.

[0182] Step S608: Define the displacement time as the periodic time, and at the end of each periodic time, swap the orientation of the first air outlet 2121 and the orientation of the second air outlet 2122, and record the number of periodic swaps.

[0183] In this embodiment, in order to make the heat shrink tubing shrink uniformly, it is necessary to repeatedly blow air onto the heat shrink tubing through the air outlet 212 to heat it multiple times. The heating and blowing time to complete one stroke is the cycle time, which is the displacement time.

[0184] After completing one heating cycle, the plastic tube needs to be controlled to move horizontally in the opposite direction. At this time, the orientation of the first air outlet 2121 and the second air outlet 2122 need to be reversed so that the air outlet 212 applies force in the opposite direction.

[0185] The number of cycle swaps refers to the number of times the heat shrink tubing completes a cycle of heating and blowing. After each cycle of heating is completed, the system accumulates the number of cycle swaps.

[0186] Step S609: When the number of cycle swaps reaches the preset number, stop the machine.

[0187] The rated number of cycles refers to the number of times the air outlet 212 reciprocates and heats the heat shrink tubing, as set by the technician. The system determines that after completing this number of cycles of heating, the heat shrink tubing can completely and evenly wrap the plastic tube. Further details are omitted here.

[0188] If the cycle swapping count has not reached the rated count, the exhaust nozzle 212 will continue to heat the heat shrink tubing. Only when the rated number of cycle swapping counts is reached will the system control the equipment to stop, awaiting the next round of welding.

[0189] Reference Figure 5 and Figure 6 The surrounding hot air method includes the following steps:

[0190] Step S610: Determine the feature length of the heat shrink tubing from the clamping position image.

[0191] The same as step S605, so it will not be repeated here.

[0192] Step S611: Determine the extension length based on the characteristic length of the heat shrink tubing and the preset axial length of the placement groove.

[0193] In this embodiment, extension plates 4 are telescopically provided on both sides of the placement groove 211 of the heating head 21 and on both sides of the cover plate 34. The extension plates 4 are telescopically controlled by the system. When the extension plates 4 are extended, the axial length of the placement groove 211 can be increased.

[0194] The extension length refers to the elongation length of the extension plate 4. The axial length of the placement groove 211 after elongation needs to be consistent with the characteristic length of the heat shrink tubing to ensure that the hot air in the placement groove 211 can heat the heat shrink tubing. The extension length is the difference between the characteristic length of the heat shrink tubing and the axial length of the placement groove. The axial length of the placement groove is a basic inherent parameter of the heating head 21, and will not be elaborated here.

[0195] Step S612: The extension plate 4, which is pre-set on the heating head 21 and the cover plate 34, is extended by the extension length control to extend the length of the placement groove 211, and the extension plate 4 is controlled to cover one section of the placement groove 211.

[0196] In this embodiment, the extension plate 4 is extended to extend the placement groove 211 so that the axial length of the placement groove 211 is consistent with the characteristic length of the heat shrink tubing. A flip cover is provided on one end of the extension plate 4, and the flip cover is controlled to be lowered to cover one end of the placement groove 211.

[0197] Step S613: Determine the rotational heating position based on the plastic tube installation image.

[0198] After the plastic tube and heat shrink tubing enter the placement groove 211, there is a gap between the heat shrink tubing and the inner wall of the placement groove 211. The rotary heating position is a certain position within this gap. When the air outlet 212 blows air at this position, the generated air can rotate axially within the placement groove 211, thus forming a rotating airflow. This position is the rotary heating position, which can be obtained from image analysis of the plastic tube installation image.

[0199] Step S614: Control the first air outlet 2121 and the second air outlet 2122 to blow air towards the symmetrical rotating heating positions to form a rotating airflow in the placement slot 211.

[0200] Once the rotary heating position is determined, the system controls both the first air outlet 2121 and the second air outlet 2122 to blow air towards the rotary heating position. The positions of the first air outlet 2121 and the second air outlet 2122 are symmetrical on both sides of the heat shrink tubing. At this time, because the top of the placement slot 211 is closed and one end of the placement slot 211 is also closed, a rotating airflow is formed within the placement slot 211. Part of the rotating airflow can leave along the axial direction of the placement slot 211 towards the opening direction, while another part of the rotating airflow can move towards the closed direction first, and then leave in the opposite direction towards the opening direction. During the above process, there is always a rotating airflow surrounding the heat shrink tubing within the placement slot 211, ensuring that the heat shrink tubing is heated uniformly around its circumference.

[0201] Reference Figure 6 The pretreatment method for the heat shrink tubing in the preparatory cavity 342 includes the following steps:

[0202] Step S7: Control the first air outlet 2121 and the second air outlet 2122 to blow air at a preset starting wind speed.

[0203] The same applies to step S602; both air outlets 212 first blow air at the initial wind speed.

[0204] In this embodiment, since the air outlet 212 has a low wind speed and low temperature at the beginning, when the heat shrink tube in the placement groove 211 is heated by the air outlet 212, the air blown out by the air outlet 212 can also heat the heat shrink tube in the preparation chamber 342 through the feeding channel 343, so that the heat shrink tube in the preparation chamber 342 shrinks in advance, so that the heat shrink tube can adapt to the diameter of the plastic tube without being too large.

[0205] Step S8: Open the feeding channel 343 and the double-sided baffles preset in the feeding channel 343 to preheat and shrink the middle part of the heat shrink tube placed in the preparation cavity 342, and collect the temperature of the placement groove.

[0206] In this embodiment, when the two air outlets 212 blow air at the initial wind speed, the system controls the material feeding channel 343 to start, and double-sided baffles are installed in the material feeding channel 343. The double-sided baffles can reduce the width of the material feeding channel 343, making the width of the material feeding channel 343 smaller than the width of the heat shrink tubing feature, so that the heat shrink tubing will not fall off even when the material feeding channel 343 is open. Furthermore, when the air blown out by the air outlets 212 heats the heat shrink tubing in the preparation chamber 342, due to the obstruction of the double-sided baffles, the hot air only heats the middle part of the heat shrink tubing, while the two ends of the heat shrink tubing remain at their original width, so that the plastic tube can be inserted from both sides of the heat shrink tubing.

[0207] The placement tank temperature refers to the ambient temperature inside the placement tank 211 under the action of hot air from the air outlet 212. The system collects the placement tank temperature through a temperature sensor integrated on the heating head 21.

[0208] Step S9: When the temperature of the placement tank reaches the preset starting temperature, close the feeding channel 343.

[0209] The initial temperature is the temperature of the air blown out of the air outlet 212 when the diameter of the heat shrink tubing in the preparatory chamber 342 is reduced to a specified width, as set by the technician. This will not be elaborated upon here.

[0210] It takes a certain amount of time for the air blown out of the air outlet 212 to reach the initial temperature. During this time, the diameter of the heat shrink tubing in the preparation chamber 342 can be reduced to the specified width. Therefore, when the air blown out of the air outlet 212 reaches the initial temperature, the system controls the material feeding channel 343 to close so that the width of the heat shrink tubing in the preparation chamber 342 should not be too small.

[0211] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A control method for a hot air welding machine for plastic pipes, applied to a hot air welding machine for plastic pipes, characterized in that, include: Acquire images of the clamping position; Determine from the clamping position image whether a plastic tube to be connected is inserted; When a plastic tube to be connected is inserted, the preset heat shrink tubing is controlled to enter the preset clamping position; Insert the two plastic tubes to be connected from both ends of the heat shrink tubing and confirm whether the connection is successful. When the two plastic pipes to be connected are successfully joined, an image of the plastic pipe installation is captured. The plastic pipe type is determined by image recognition of the plastic pipe to be connected from the plastic pipe installation image. The plastic pipe type includes segmented plastic pipe and continuous plastic pipe. For segmented plastic pipes, the air outlet (212) is controlled by a preset rotary connection method to blow hot air onto the plastic pipe and make the plastic pipe rotate in the placement groove (211); For continuous plastic tubes, the air outlet (212) blows hot air and is heated in a surrounding hot air manner using a preset circulating hot air method; A hot air welding machine for plastic pipes includes a control box (1), a hot air mechanism (2) disposed in the control box (1) and used to blow air to heat the plastic pipes to be connected, and a clamping mechanism (3) for clamping the plastic pipes. The hot air mechanism (2) includes a heating head (21) for placing the connection part of the plastic tube, an air supply pipe (22) for connecting the heating head (21) and the control box (1) and for providing an air source, and a heating pipe (23) for heating the heating head (21); the heating head (21) has a placement groove (211) for radially inserting the plastic tube and the inner wall of the placement groove (211) has symmetrical air outlets (212). The clamping mechanism (3) includes a lifting cylinder (31) and a clamping plate (32) mounted on the lifting cylinder (31); the clamping plate (32) has clamping components (33) at both ends for clamping two plastic tubes respectively; the lifting cylinder (31) drives the clamping plate (32) to rise and fall to put the two plastic tubes with heat shrink tubing sleeves into the placement slot (211); The clamping assembly (33) includes an upper clamping piece (331) and a lower clamping piece (332). The lower clamping piece (332) has a fixing rod (333) at its top, and the upper clamping piece (331) is sleeved on the fixing rod (333). The fixing rod (333) is provided with a compression spring (334) for pressing the upper clamping piece (331) against the lower clamping piece (332). The upper clamp (331) and the lower clamp (332) are bent in opposite directions to form a perforation (335) through which the plastic tube passes; the top of the clamping plate (32) is rotatably provided with a cover plate (34) that covers the top opening of the placement groove (211), and the cover plate (34) is concave upward with an arc surface (341); the air outlet (212) includes a first air outlet (2121) and a second air outlet (2122), and the openings of the first air outlet (2121) and the second air outlet (2122) can be adjusted up and down by rotation.

2. The control method for a hot air welding machine for plastic pipes according to claim 1, characterized in that, Methods for confirming successful connection of plastic pipes include: Extract heat shrink tubing features from the clamping position image, and determine the heat shrink tubing feature length based on the heat shrink tubing features; The position of the middle part of the heat shrink tubing is determined based on its characteristic length. Control the clamping arm preset on the cover plate (34) to clamp the middle position of the heat shrink tube, and apply force to the middle position of the heat shrink tube with a preset clamping force; The insertion distance of the plastic tube is determined based on the characteristic length of the heat shrink tubing and the midpoint position of the heat shrink tubing. Insert the plastic tube into both ends of the heat shrink tubing according to the specified insertion distance, and collect the pressure on the clamping arm; When the pressure reaches the preset compressive force, the clamping arm is controlled to release the heat shrink tubing.

3. The control method for a hot air welding machine for plastic pipes according to claim 2, characterized in that, Also includes: Based on the position of the middle part of the heat shrink tubing and the preset control distance, the positions of the control groups located on both sides of the middle part of the heat shrink tubing are determined. The clamping arm is controlled to clamp the middle position of the heat shrink tubing and the control group position with a preset detection force, and the pressure surface area of ​​the middle position and the pressure surface area of ​​the control group are collected. When the area of ​​the central pressure-bearing surface is inconsistent with the area of ​​the control group pressure-bearing surface, the difference between the area of ​​the central pressure-bearing surface and the area of ​​the control group pressure-bearing surface is calculated and defined as the misalignment area; The adjustment distance is determined based on the misalignment area and the preset plastic pipe diameter. The plastic tube is pulled out to both sides according to the adjusted distance.

4. The control method for a hot air welding machine for plastic pipes according to claim 1, characterized in that, The rotary connection method includes: Determine the forward heating position and the rotation tangent point position based on the plastic tube installation image; The first air outlet (2121) is controlled to face the positive heating position, and the second air outlet (2122) is controlled to face the rotation tangent position; The second air outlet (2122) is controlled to blow air at a preset initial wind speed, and the initial wind speed is increased by a preset wind speed increment to reach a preset maximum wind speed. The rotation state of the plastic tube is identified based on the plastic tube installation image. When the rotation state of the plastic tube is consistent with the preset uniform rotation state, the maximum wind speed is reduced by a preset wind speed reduction to bring the plastic tube to a preset critical rotation state, the rotation speed of the plastic tube is collected, and the heating temperature is matched according to the rotation speed of the plastic tube. The first air outlet (2121) is controlled to blow air onto the plastic tube at the heating temperature to uniformly shrink the heat shrink tube circumferentially; When the rotation state of the plastic tube is inconsistent with the uniform rotation state, the first air outlet (2121) is controlled to face the rotation tangent position and blow air at the maximum wind speed; At the same time, the maximum wind speed of the first air outlet (2121) and the second air outlet (2122) is adjusted, and the maximum wind speed is reduced by the wind speed reduction to bring the plastic tube to the critical rotation state, and the rotation speed of the plastic tube is collected. The heating temperature is matched according to the rotation speed of the plastic tube, and the first air outlet (2121) and the second air outlet (2122) are controlled to blow air at the heating temperature simultaneously.

5. The control method for a hot air welding machine for plastic pipes according to claim 4, characterized in that, Also includes: Determine the feature length of the heat shrink tubing from the clamping position image; The lateral displacement speed of the plastic tube is matched according to the rotational speed of the plastic tube. The displacement time is determined based on the characteristic length of the heat shrink tubing and the lateral displacement velocity of the plastic tube. The displacement time is defined as the periodic time. At the end of each periodic time, the orientation of the first air outlet (2121) and the orientation of the second air outlet (2122) are swapped, and the number of periodic swaps is recorded. The machine stops when the number of cycle swaps reaches the preset limit.

6. The control method for a hot air welding machine for plastic pipes according to claim 1, characterized in that, The surrounding hot air method includes: Determine the feature length of the heat shrink tubing from the clamping position image; The extension length is determined based on the characteristic length of the heat shrink tubing and the preset axial length of the placement groove; The extension plate (4) preset in the heating head (21) and the cover plate (34) is extended by the extension length control to extend the length of the placement groove (211), and the extension plate (4) is controlled to cover one section of the placement groove (211); Determine the rotary heating position based on the plastic tube installation image; Control the first air outlet (2121) and the second air outlet (2122) to blow air towards the symmetrical rotating heating positions to form a rotating airflow in the placement slot (211).

7. The control method for a hot air welding machine for plastic pipes according to claim 1, characterized in that, The top of the cover plate (34) has a preparatory cavity (342) for placing the heat shrink tubing, the preparatory cavity (342) has a discharge channel (343) communicating with the placement slot (211), and further includes: The first air outlet (2121) and the second air outlet (2122) are controlled to blow air at a preset initial wind speed; The material feeding channel (343) and the double-sided baffles preset in the material feeding channel (343) are opened to preheat and shrink the middle part of the heat shrink tube placed in the preparatory cavity (342), and the temperature of the placement groove is collected. When the temperature of the placement tank reaches the preset starting temperature, the feeding channel (343) is closed.

Images