Temperature control system and control method for powder spreading surface

Abstract

The invention discloses a temperature control system for a powder laying surface and a control method of the temperature control system, belongs to the field of metal 3D printing equipment, and aims to solve the problem that the temperature of the powder laying surface for metal printing is difficult to control, the temperature control system comprises a heating device, a temperature acquisition device and a data processing device, and the heating device, the temperature acquisition device and the data processing device are electrically connected pairwise. Mutual information transmission is realized; the heating device is used for heating the powder spreading surface so as to ensure that the temperature of the powder spreading surface is kept within a set range; the temperature acquisition device is used for acquiring the actual temperature of the powder spreading surface; and the data processing device is used for processing temperature data and image data from the temperature acquisition device and the image acquisition device. Precise control over the surface temperature of the powder laying face is achieved, and the problem that metal products are scrapped due to the fact that the surface temperature difference of the powder laying face is too large is solved.

Description

Technical Field

[0001] The invention relates to metal 3D printing equipment, and in particular to temperature control of a powder spreading surface. Background Art

[0002] With the demand for lightweight and integrated structure and function, high-strength metal parts are widely used in the fields of automobiles, aerospace, etc. However, due to their poor casting performance, it is difficult to form complex parts using traditional processing methods, and large metal components are even more expensive and have a long manufacturing cycle. Binder jet metal 3D printing realizes the production of high-strength metal parts with complex structures by stacking materials layer by layer without the need to manufacture green embryos, but this method has extremely high requirements for temperature control on the powder-laying surface. Most of the current temperature measurement systems use a single-point moving method to perform local temperature measurement, and cannot monitor the stability of the entire powder-laying surface, making it easy for binder jet metal printing products to cause product quality defects due to excessive temperature on the powder-laying surface. To solve this problem, Chinese patent CN108312498A discloses a 3D printing temperature measurement system, which can be moved up and down above the printing platform, and the temperature measurement system includes a print head and a temperature measuring head embedded body installed on a printing base, wherein the temperature measuring head embedded body is fixedly installed on the printing base through a column, and the temperature measuring head embedded body is arranged above the latest layer of printed thin film. Compared with the prior art, the present invention has the advantages of simple structure, safety, reliability, extremely low price, repeated use, and the ability to measure the temperature of the latest printed sheet in real time with high measurement accuracy. However, this technical solution still cannot achieve the purpose of monitoring the entire powdering surface. Summary of the invention

[0003] In view of the problem that the above-mentioned powdering surface temperature control cannot fully monitor the temperature of the entire powdering surface, it is necessary to propose a powdering surface control system and a control method thereof, which can achieve precise control of the temperature of the entire powdering surface.

[0004] A temperature control system for a powder-laying surface, comprising a heating device, a temperature acquisition device, an image acquisition device and a data processing device, wherein the above-mentioned devices are electrically connected to achieve control and monitoring of the temperature of the powder-laying surface, so that the temperature of the entire powder-laying surface is balanced; the heating device is used to heat the powder-laying surface to ensure that the temperature of the powder-laying surface is maintained within a set range; the temperature acquisition device is used to collect the actual temperature of the powder-laying surface; the image acquisition device is used to generate an image of the powder-laying surface; the data processing device is used to process temperature data and image data from the temperature acquisition device and the image acquisition device, so as to achieve balanced control of the temperature of the entire powder-laying surface.

[0005] A method for controlling the temperature of flour-pasted noodles, comprising:

[0006] S01, dividing the powder spreading surface into a number of temperature detection zones that can be heated independently;

[0007] S02, a temperature acquisition device collects the temperatures of at least three different points in the temperature detection area, and calculates the average value of the temperatures of the discrete points, where the average value is the surface temperature of the temperature detection area;

[0008] S03, the image acquisition device generates a temperature image of the entire powdering surface by using the surface temperatures of each temperature detection zone acquired by the temperature acquisition device;

[0009] S04, the data processing device compares the received actual temperature of the temperature detection area with the set temperature to obtain the temperature difference between the two;

[0010] S05, if the temperature difference exceeds the set range, the heating device heats the temperature detection area to restore the actual temperature of the temperature detection area to within the set temperature range.

[0011] Through the above temperature control method, it is ensured that the actual temperature of each temperature detection area of ​​the powder spreading surface can always be maintained within the set temperature range, thereby effectively ensuring the quality of the metal liquid printing products and avoiding the problem of powder sticking and pushing due to excessive temperature changes.

[0012] The beneficial effects of the technical solution of the present invention are as follows: by dividing the entire powder-laying surface into a number of temperature detection zones that can be heated independently, and detecting and controlling the actual temperature of each temperature detection zone, the surface temperature of the entire powder-laying surface is effectively guaranteed to be balanced and within the temperature-controlled range, thereby avoiding the problem of powder sticking and powder pushing due to excessive temperature changes, which would render the printed metal product scrapped. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the temperature control system for spreading flour noodles;

[0014] Figure 2 It is a schematic diagram of the temperature detection method of flour-laying noodles. DETAILED DESCRIPTION

[0015] In order to more clearly illustrate the technical solution of the present invention, the technical solution of the invention content is described in detail in conjunction with the accompanying drawings. Obviously, the following descriptions are some typical embodiments of the present invention. For ordinary technicians in this field, other solutions can be obtained based on these embodiments without paying creative work.

[0016] The invention aims to solve the problem of scrapping or substandard quality of metal products caused by excessive temperature change on the surface of the powdering surface.

[0017] One implementation method, such as Figure 1 As shown, a temperature control system for a powder-laying surface comprises a heating device, a temperature acquisition device, an image acquisition device and a data processing device. The above-mentioned devices are electrically connected to realize the control and monitoring of the temperature of the powder-laying surface, so that the temperature of the entire powder-laying surface is balanced; the heating device is used to heat the powder-laying surface to ensure that the temperature of the powder-laying surface is maintained within a set range; the temperature acquisition device is used to collect the actual temperature of the powder-laying surface; the image acquisition device is used to generate an image of the powder-laying surface; the data processing device is used to process the temperature data and image data from the temperature acquisition device and the image acquisition device, so as to realize balanced control of the temperature of the entire powder-laying surface.

[0018] As a supplement to the present embodiment, the heating device is arranged just above the powdering surface and is movably provided with several groups, and each group of the heating device can heat any area of ​​the powdering surface. In the present embodiment, in order to reduce the manufacturing cost of the temperature control system, the number of groups of the heating device is less than the number of temperature detection zones. By moving the position of the heating device, the heating device can be scheduled, and each group of the heating device can heat each temperature detection zone. Specifically, the heating device can be a radiant heater or a plate heater arranged just above the powdering surface, such as a radiant lamp tube. When the surface temperature of the powdering surface is lower than the set range, the radiant lamp tube can be turned on to irradiate the temperature detection zone of the powdering surface to ensure that the temperature of the temperature detection zone is always within the set range, thereby ensuring the printing effect of the metal product.

[0019] As a supplement to this embodiment, the temperature acquisition device can be an infrared generating device, which is arranged above the powdering surface and detects the actual surface temperature of the powdering surface by projecting infrared rays onto the powdering surface. In this embodiment, there are at least three infrared beams projected onto the powdering surface, thereby achieving the purpose of detecting the actual temperatures of at least three points at the same time. Furthermore, at least one group of temperature acquisition devices can be arranged above the powdering surface, thereby conveniently and quickly realizing the rapid detection of the actual surface temperature of the powdering surface.

[0020] As a supplement to this embodiment, the image acquisition device can be an infrared camera, which takes photos of each temperature detection area and combines them to generate a two-dimensional temperature image of the entire powdering surface, which vividly displays the actual temperature of the entire powdering surface in the form of a graphic, and serves as a record for quality monitoring and traceability.

[0021] As a supplement to the present embodiment, the data processing device is used to process the actual temperature obtained, specifically, to make a difference between the actual temperature and the set temperature to obtain the temperature difference. If the temperature difference falls within the set range, the heating device will not be started. If the temperature difference exceeds the set range, the heating device will be started to achieve control and regulation of the temperature of the powder-laying surface. Specifically, because the initial temperature heating is controlled within the set temperature range, after stopping heating for a period of time, the surface temperature of the powder-laying surface will decrease, that is, the data processing device provides a negative feedback signal. In layman's terms, since the temperature of the powder-laying surface is raised to the set temperature by the heating device, and after stopping heating, the surface temperature of the powder-laying surface will only gradually decrease. When the temperature of the powder-laying surface drops to the lower limit of the set range, the heating device is started to heat the powder-laying surface so that the surface temperature of the powder-laying surface returns to the set range.

[0022] As a supplement to the present embodiment, the temperature control system of the powdered surface also includes a control device, which is used to control the start and stop of the heating device, to control the temperature acquisition device and to receive the acquired temperature data, to control the image acquisition device and to control the data processing device, so as to realize the good operation of the entire temperature control system, timely acquisition and storage of data, etc.

[0023] In another embodiment, based on the temperature control system, the method for controlling the stability of the powdered surface comprises:

[0024] S11, dividing the powder-laying surface into a plurality of independently heated temperature detection zones; in this embodiment, the powder-laying surface can be divided into eight temperature detection zones, each of which can independently receive heating from the heating device;

[0025] S12, the temperature acquisition device collects the temperatures of at least three different points in the temperature detection area, and averages the temperatures of the discrete points, the average value being the surface temperature of the temperature detection area; specifically, five points are set in each temperature detection area, and the infrared generating device simultaneously emits five infrared beams, which are irradiated on the five points to detect the actual temperature of the current temperature detection area, and the actual temperatures of the five points are added and averaged to obtain the actual surface temperature of the current temperature detection area;

[0026] S13, the image acquisition device generates a temperature image of the entire powder laying surface using the surface temperatures of each temperature detection zone acquired by the temperature acquisition device; specifically, the infrared camera scans the entire current powder laying surface, acquires the surface temperature of each temperature detection zone, and generates a temperature image of the powder laying surface;

[0027] S14, the data processing device compares the received actual temperature of the temperature detection area with the set temperature to obtain the temperature difference between the two; specifically, in the data processing device, the set temperature is subtracted from the actual temperature to obtain the temperature difference between the two;

[0028] S15, if the temperature difference exceeds the set range, the temperature detection area is heated by the heating device to restore the actual temperature of the temperature detection area to within the set temperature range.

[0029] As a supplement to this embodiment, in S13, the temperature image can also be drawn by the actual surface temperature of each temperature detection area, that is, the temperature control system may not be provided with the image acquisition device, thereby saving the production cost of the temperature control system.

[0030] As a supplement to the present embodiment, the temperature image is in the form of two-dimensional data, which can be displayed in the form of color blocks, or the temperature value of each color block can be marked on the basis of the color blocks, so as to facilitate quality traceability.

[0031] As a supplement to this embodiment, the set temperature is a basic temperature ±0.1° C., and the basic temperature is the temperature required for printing metal products of different materials.

[0032] As a supplement to this embodiment, in S15, the setting range includes a first setting range and a second setting range, the first setting range is a temperature difference exceeding 0.5°C, and the second setting range is a temperature difference exceeding 0.1°C-0.5°C; if the temperature difference falls within the first setting temperature range, the proportional control method is used to heat the current temperature detection area; if the temperature difference falls within the second setting temperature range, the integral control method is used to heat the current temperature detection area.

[0033] As a supplement to the present embodiment, in S15, the time interval for temperature adjustment of each temperature detection zone is 1ms to 10ms. This time interval can effectively ensure that the temperature drop in the temperature detection zone will not exceed the time that causes the product to be scrapped or of unqualified quality, thereby effectively reducing production energy consumption while ensuring product quality.

[0034] It should be supplemented that the temperature acquisition device continuously detects the actual temperature of each temperature detection zone, and the data processing device can plot the actual surface temperature of each temperature detection zone as a temperature curve; the image acquisition device images the entire powdering surface at intervals.

[0035] The present invention realizes accurate control of the surface temperature of the powdering surface, thereby avoiding the problem of scrapping of metal products caused by excessive temperature difference on the surface of the powdering surface.

[0036] The above embodiments are merely descriptions of a typical application of the technical solution of the present invention, and reasonable expansion can be carried out on a reasonable basis without requiring creative work.

Claims

1. A temperature control system for flour-spreading, characterized in that: It includes a heating device, a temperature acquisition device and a data processing device, wherein the heating device, the temperature acquisition device and the data processing device are electrically connected in pairs to realize the transmission of information between each other; The heating device is used to heat the powder-laying surface to ensure that the temperature of the powder-laying surface is maintained within a set range; the temperature acquisition device is used to collect the actual temperature of the powder-laying surface; The data processing device is used for processing the temperature data and the image data from the temperature acquisition device and the image acquisition device.

2. The temperature control system for flour-pasting noodles according to claim 1, characterized in that: It also includes an image acquisition device, which is used to generate an image of the powdering surface.

3. The temperature control system for flour-pasting noodles according to claim 2, characterized in that: The heating device is arranged just above the powdering surface and is movably provided in several groups, and each group of the heating device can heat any area of ​​the powdering surface.

4. The temperature control system for flour-pasting noodles according to claim 2, characterized in that: The temperature acquisition device may be an infrared generating device, which is disposed above the powdering surface and detects the actual surface temperature of the powdering surface by projecting infrared rays onto the powdering surface.

5. The temperature control system for flour-pasting noodles according to claim 2, characterized in that: The image acquisition device may be an infrared camera, which takes photos of each temperature detection zone and combines them to generate a temperature image of the entire powdering surface.

6. The temperature control system for flour-pasting noodles according to claim 2, characterized in that: It also includes a control device, which is used to control the start and stop of the heating device, to control the temperature acquisition device and receive the acquired temperature data, to control the image acquisition device and to control the data processing device, so as to achieve the good operation of the entire temperature control system and the timely acquisition and storage of data.

7. The method for controlling the temperature control system of the powdered surface according to any one of claims 2 to 6, characterized in that: include, S01, dividing the powder spreading surface into a number of temperature detection zones that can be heated independently; S02, a temperature acquisition device collects the temperatures of at least three different points in the temperature detection area, and calculates the average value of the temperatures of the discrete points, where the average value is the surface temperature of the temperature detection area; S03, the image acquisition device generates a temperature image of the entire powdering surface by using the surface temperatures of each temperature detection zone acquired by the temperature acquisition device; S04, the data processing device compares the received actual temperature of the temperature detection area with the set temperature to obtain the temperature difference between the two; S05, if the temperature difference exceeds the set range, the heating device heats the temperature detection area to restore the actual temperature of the temperature detection area to within the set temperature range.

8. The method for controlling the temperature of flour-pasted noodles according to claim 7, characterized in that: The set temperature is the basic temperature ±0.1°C, and the basic temperature is the temperature required for printing metal products of different materials.

9. The method for controlling the temperature of flour-pasted noodles according to claim 7, characterized in that: In S05, the setting range includes a first setting range and a second setting range, the first setting range is a temperature difference exceeding 0.5°C, and the second setting range is a temperature difference exceeding 0.1°C-0.5°C; if the temperature difference falls within the first setting temperature range, the proportional control method is used to heat the current temperature detection area; if the temperature difference falls within the second setting temperature range, the integral control method is used to heat the current temperature detection area.

10. The method for controlling the temperature of flour-pasted noodles according to claim 7, characterized in that: In S05 , the time interval for adjusting the temperature of each temperature detection zone is 1 ms to 10 ms.

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