Automatic coating device for tubular metal workpieces

Abstract

An automatic coating device for tubular metal workpieces is suitable for moving within a through groove surrounding the inner circumference of the workpiece. The automatic coating device includes a moving unit, a spraying unit, and a control unit. The moving unit includes a telescopic shaft, a housing fixed to the telescopic shaft, a plurality of adjusting arms extending radially from the housing, and a plurality of guide wheels pivotally mounted on the adjusting arms. The spraying unit includes a nozzle pivotally mounted on the telescopic shaft and a power source capable of rotating the nozzle. The power source drives the nozzle to rotate for coating. The control unit can detect whether the housing is eccentric and reposition the nozzle by controlling the radial extension and retraction of the adjusting arms, ensuring that the nozzle and the tubular metal workpiece remain coaxial.

Description

Technical Field

[0001] This invention relates to a coating apparatus, and more particularly to an automatic coating apparatus for spraying a coating onto the inner circumferential surface of a tubular metal workpiece. Prior Technology

[0002] Traditional tubular metal workpieces such as steel pipes possess advantages such as high strength, high toughness, strong impact resistance, and ease of processing. However, under special environmental conditions or usage states, additional reinforcement properties are still required. Therefore, coatings are often applied to the inner circumference of steel pipes to achieve effects such as corrosion resistance, reduced friction, or altered roughness. However, due to the annular structure of the inner circumference of steel pipes, manual coating methods are generally difficult to implement. Currently, a rotatable nozzle is often inserted into the steel pipe to spray the coating onto its inner circumference. However, during the axial movement of the nozzle within the steel pipe, it is easily disturbed and wobbles radially, causing the nozzle's rotation axis to deviate from the central axis of the steel pipe. This can easily lead to uneven coating. Summary of the Invention

[0003] Therefore, the object of the present invention is to provide an automatic coating device that can automatically align to avoid eccentricity.

[0004] Therefore, the automatic coating device for tubular metal workpieces of the present invention is suitable for movement within a through groove surrounding the inner circumferential surface of the tubular metal workpiece. The automatic coating device includes a moving unit, a spraying unit, and a control unit. The moving unit includes a telescopic shaft extending axially along the tubular metal workpiece into the through groove, a housing fixed to the telescopic shaft and reciprocating within the through groove by the telescopic shaft, a plurality of adjusting arms extending radially from the housing, and a plurality of guide wheels pivotally mounted on the adjusting arms and rollingly contacting the inner circumferential surface of the tubular metal workpiece. Each adjusting arm can be controlled to extend and retract radially relative to the housing.

[0005] The spraying unit includes a nozzle pivotally mounted on the telescopic shaft, a power source capable of rotating the nozzle relative to the telescopic shaft, a liquid delivery pipe embedded in the telescopic shaft and connected to the nozzle, and a material supply source located outside the through groove and connected to the liquid delivery pipe. The control unit includes a positioning sensor mounted on the moving unit and a controller that signals the positioning sensor and the adjusting arms. When the positioning sensor detects that the central axis of the housing is not coaxial with the central axis of the tubular metal workpiece, the controller controls the adjusting arms to adjust their respective lengths so that the housing moves radially to realign.

[0006] The advantages of this invention are as follows: the material supply source inputs the liquid material to be coated into the infusion tube, and the nozzle outputs it to spray the inner circumferential surface of the tubular metal workpiece. The telescopic shaft can extend and retract axially to move the housing and the nozzle within the through groove. When the positioning sensor detects that the central axis of the housing is not coaxial with the central axis of the tubular metal workpiece, the controller can control the adjusting arms to adjust their respective lengths, thereby allowing the housing to move radially, which in turn drives the telescopic shaft connected to the housing and the nozzle mounted on the telescopic shaft to realign, ensuring that the nozzle and the tubular metal workpiece remain coaxial and that any eccentricity can be corrected in real time. Simple Explanation of the Diagram

[0007] Other features and effects of the present invention will be clearly presented in the embodiments with reference to the drawings, wherein: Figure 1 is a schematic diagram illustrating an embodiment of the automatic coating device for tubular metal workpieces of the present invention. Implementation

[0008] Referring to Figure 1, an embodiment of the automatic coating device for tubular metal workpieces of the present invention is applicable to moving within a through groove 11 surrounding the inner circumferential surface of a tubular metal workpiece 1. The automatic coating device includes a moving unit 2, a spraying unit 3, a control unit 4, and an exhaust gas treatment unit 5. The moving unit 2 includes a telescopic shaft 21 extending axially into the through groove 11 and coaxially aligned with the tubular metal workpiece 1, a housing 22 fixed to the telescopic shaft 21 and surrounding an internal space 221, six adjusting arms 23 extending radially from the outer circumferential surface of the housing 22, and six guide wheels 24 respectively pivotally mounted at the ends of the adjusting arms 23 and rollingly contacting the inner circumferential surface of the tubular metal workpiece 1. The adjusting arms 23 can be grouped into groups of three. The adjusting arms 23 in different groups are spaced apart from each other along the axial direction. The three adjusting arms 23 in the same group are arranged in a ring at equal angles along the circumference. Of course, the above quantity and grouping method are only examples. In practice, the quantity and configuration can be adjusted according to the length of the housing 22 and other requirements.

[0009] The spraying unit 3 includes a nozzle 31 pivotally mounted at the end of the telescopic shaft 21, a power source 32 mounted on the telescopic shaft 21 and capable of rotating the nozzle 31 relative to the telescopic shaft 21, an infusion tube 33 embedded in the telescopic shaft 21 and connected to the nozzle 31, and a feed source 34 located outside the through groove 11 and connected to the infusion tube 33. The control unit 4 includes a positioning sensor 41 mounted on the moving unit 2, a plurality of thickness measuring instruments 42 respectively mounted on the adjusting arms 23, and a controller 43 that connects the positioning sensor 41, the adjusting arms 23, the thickness measuring instruments 42, the power source 32, the feed source 34, and the telescopic shaft 21. The thickness measuring instruments 42 can also be of other numbers and positions, and can detect the thickness of the target by means of infrared or laser. The exhaust gas treatment unit 5 includes a negative pressure air pump 51 disposed in the housing 22 and connected to the internal space 221, and an exhaust pipe 52 connected to the housing 22 and extending to the outside of the through groove 11.

[0010] The telescopic shaft 21 can be extended and retracted axially under the control of the controller 43, thereby driving the housing 22 to reciprocate within the through groove 11. Each adjusting arm 23 can be extended and retracted radially relative to the housing 22 under the control of the controller 43, thus allowing adjustment according to the inner diameter of the tubular metal workpiece 1. After the moving unit 2 enters the through groove 11, the guide wheels 24 can abut against the inner circumferential surface of the tubular metal workpiece 1. With the assistance of the guide wheels 24 and the adjusting arms 23, the telescopic shaft 21 can be kept coaxially aligned with the tubular metal workpiece 1. The material supply source 34 can deliver the liquid to be sprayed to the nozzle 31 through the liquid delivery pipe 33. The power source 32 drives the nozzle 31 to rotate, so as to spray the liquid circumferentially onto the inner surface of the tubular metal workpiece 1.

[0011] The thickness gauge 42 mounted on the adjusting arms 23 can detect the coating thickness in different areas of the inner surface of the tubular metal workpiece 1. After the thickness gauge 42 obtains the measurement results, the controller 43 can adjust the moving speed and direction of the telescopic shaft 21, control the rotation speed of the nozzle 31, and the pressure and / or flow rate of the liquid material delivered by the material supply source 34. Accordingly, the coating thickness at various locations can be automatically compensated based on the real-time measurement results of the thickness gauge 42. In addition, the negative pressure air pump 51 can be controlled to create a negative pressure state in the internal space 221, so as to draw the waste gas in the channel 11 into the internal space 221 and send it to the outside for collection or discharge through the exhaust pipe 52. Of course, if the amount of waste gas is small, the exhaust pipe 52 may not be installed, and the waste gas may simply be drawn into the internal space 221 through the negative pressure air pump 51 for storage.

[0012] When the positioning sensor 41 detects that the central axis of the housing 22 is not coaxial with the central axis of the tubular metal workpiece 1, the controller 43 controls the adjusting arms 23 to adjust their respective lengths. By extending some adjusting arms 23 and shortening others, the position of the housing 22 relative to the tubular metal workpiece 1 can be adjusted radially, thereby aligning the telescopic shaft 21 coaxially with the tubular metal workpiece 1. The aforementioned adjustment method can also be used to align the telescopic shaft 21 coaxially with the tubular metal workpiece 1 when the moving unit 2 first enters the tubular metal workpiece 1, while simultaneously causing the guide wheels 24 to abut against the inner circumferential surface of the tubular metal workpiece 1.

[0013] In summary, with the assistance of the guide wheels 24, the present invention can move smoothly in the through groove 11. By adjusting the adjustment arms 23, it can be ensured that the telescopic shaft 21 and the nozzle 31 coaxially arranged therewith can remain coaxial with the central axis of the tubular metal workpiece 1. At the same time, the thickness measuring instruments 42 can monitor the coating thickness in real time and ensure the uniformity of the coating thickness through real-time compensation. Therefore, the purpose of the present invention can be achieved.

[0014] However, the above description is merely an embodiment of the present invention and should not be construed as limiting the scope of the present invention. Any simple equivalent changes and modifications made in accordance with the scope of the patent application and the contents of the patent specification shall still fall within the scope of the patent of the present invention.

[0015] 1: Tubular metal workpiece 11: Through slot 2: Moving Unit 21: Telescopic shaft 22: Shell 221: Interior Space 23: Adjusting arm 24: Guide wheel 3: Spraying Unit 31: Sprayer Head 32: Power Source 33: Infusion tube 34: Source of materials 4: Control Unit 41: Positioning Sensor 42: Thickness measuring instrument 43: Controller 5: Exhaust Gas Treatment Unit 51: Negative pressure air pump 52: Exhaust pipe

Claims

1. An automatic coating device for a tubular metal workpiece, suitable for moving within a through groove surrounding the inner circumferential surface of the tubular metal workpiece, the automatic coating device comprising: a moving unit including a telescopic shaft extending axially from the tubular metal workpiece into the through groove, a housing fixed to the telescopic shaft and reciprocating within the through groove by being driven by the telescopic shaft, a plurality of adjusting arms extending radially from the housing, and a plurality of guide wheels pivotally mounted on the adjusting arms and rollingly contacting the inner circumferential surface of the tubular metal workpiece, each adjusting arm being controllable to extend and retract radially relative to the housing; A spraying unit includes a nozzle pivotally mounted on a telescopic shaft, a power source capable of rotating the nozzle relative to the telescopic shaft, a liquid inlet pipe embedded in the telescopic shaft and connected to the nozzle, and a material supply source located outside the through groove and connected to the liquid inlet pipe; and a control unit including a positioning sensor mounted on the moving unit and a controller signal-connected to the positioning sensor and the adjusting arms. When the positioning sensor detects that the central axis of the housing is not coaxial with the central axis of the tubular metal workpiece, the controller controls the adjusting arms to adjust their respective lengths so that the housing moves radially and is repositioned.

2. The automatic coating apparatus for tubular metal workpieces as described in claim 1, wherein, The control unit also includes at least one thickness measuring device connected to the controller signal. The controller signal is connected to the power source of the spraying unit and the material supply source. The controller can control the power source to adjust the rotation speed of the nozzle and can control the material supply source to adjust the pressure and / or flow rate of the liquid material delivery.

3. The automatic coating apparatus for tubular metal workpieces as described in claim 1, wherein, The controller signal of the control unit is connected to the telescopic shaft, and the controller can control the moving speed and moving direction of the telescopic shaft.

4. The automatic coating apparatus for tubular metal workpieces as described in claim 1, wherein, The housing surrounds an internal space. The automatic coating device also includes an exhaust gas treatment unit, which includes a negative pressure air pump disposed in the housing and communicating with the internal space. The negative pressure air pump can be controlled to create a negative pressure state in the internal space so as to draw the gas in the channel into the internal space.

5. The automatic coating apparatus for tubular metal workpieces as described in claim 4, wherein, The exhaust gas treatment unit also includes an exhaust pipe that connects to the housing and extends to the outside of the channel.

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