Substrate and powder bed constant-temperature heating system based on SLM

Abstract

The utility model relates to the technical field of selective laser melting metal 3D printing, in particular to a substrate and powder bed constant-temperature heating system based on SLM, which comprises a printing forming chamber, a liftable substrate assembly arranged in the printing forming chamber, a first heating pipeline arranged in the printing forming chamber, a second heating pipeline arranged in the substrate assembly, and a third heating pipeline arranged in the second heating pipeline. The constant-temperature heating system further comprises a heating circulation assembly and a temperature control system, the temperature control system is electrically connected with the heating circulation assembly, and the heating circulation assembly is communicated with the first heating pipeline and the second heating pipeline and used for providing constant-temperature heating hot water for the first heating pipeline and the second heating pipeline. And the substrate and the powder bed are heated around the forming chamber, so that rapid and uniform constant-temperature heating is realized.

Description

Technical Field

[0001] The utility model relates to the technical field of laser selective melting metal 3D printing, and in particular to a constant temperature heating system for a substrate and a powder bed based on SLM. Background Art

[0002] Selective laser melting (SLM) metal 3D printing technology is an additive manufacturing method that uses a laser beam to selectively heat and melt powder materials to deposit and shape them layer by layer. The process is usually as follows: first, a layer of metal powder is spread on the substrate or the deposited solid surface with a powder spreading mechanism, and then a high-energy focused laser beam is used to quickly irradiate the powder along a certain scanning path. The irradiated powder melts and solidifies to form a deposition layer. After depositing a layer, the substrate is lowered to a certain height, and then another layer of powder is spread for laser scanning. The above process is repeated until the entire part is formed.

[0003] In traditional 3D printing chambers, the preheating of the printer substrate and powder is generally done by electrical heating. The preheating process is usually achieved by designing routing channels on the heating plate. These channels need to be evenly distributed on the heating plate to ensure uniform heating of the entire heating surface. Since the wires need to pass through the back of the heating plate, the channels are usually opened on the back of the heating plate, and the substrate is located above the channels. After the channels are routed, copper is used to cover the contact points because copper has good thermal conductivity and can quickly transfer heat. Heat is first generated by the resistor, then conducted to the heating plate through copper, then to the substrate, and finally to the powder layer to achieve preheating of the powder layer. As the printing process progresses, the powder layer becomes thicker and thicker, and there are more heat transfer processes. In order to monitor the preheating temperature, two temperature sensors are usually installed on the back of the heating plate to monitor half of the heating plate respectively to ensure that the preheating temperature is controlled within a certain range. When the temperature exceeds the preheating temperature, heating is stopped; when the temperature is lower than the preheating temperature, heating is restarted.

[0004] However, there are some problems with the use of electric heating. For example, as the size of the SLM equipment increases, the amount of heat required continues to increase, resulting in an increase in the heating current. Wiring will become difficult and there will be a greater safety hazard. In addition, electric heating is prone to risks such as short circuits and metal powder detonation. In addition, electric heating reaches the powder layer indirectly through heat conduction, so the temperature transfer gradient is large, and the consistency of the ambient temperature cannot be guaranteed. In addition, there are differences in the thickness of the substrate, resulting in a large temperature difference on the surface of the substrate, which affects the printing quality of the parts. At the same time, when the preheating temperature is high, a longer heating time is required, which causes the ambient temperature to rise, the heating plate to expand and deform, and it is easy to get stuck, which affects the problem of printing interruption. Utility Model Content

[0005] In order to solve the above technical problems, the utility model provides a constant temperature heating system for a substrate and a powder bed based on SLM, which adopts liquid heating to heat the substrate and the powder bed around the forming chamber to achieve the purpose of fast and uniform constant temperature heating.

[0006] The utility model is realized by the following technical solutions:

[0007] A constant temperature heating system for a substrate and a powder bed based on SLM, comprising a printing forming chamber, a liftable substrate assembly in the printing forming chamber, a heating pipe 1 being provided in the printing forming chamber, a heating pipe 2 being provided in the substrate assembly, the constant temperature heating system further comprising a heating circulation assembly and a temperature control system, the temperature control system being electrically connected to the heating circulation assembly, the heating circulation assembly being respectively connected to the heating pipe 1 and the heating pipe 2, and being used for providing constant temperature heated hot water to the heating pipe 1 and the heating pipe 2.

[0008] Further preferably, the substrate assembly includes a printer substrate, a heating copper plate and a heat insulation plate 1 which are arranged in sequence from top to bottom, a heating pipe 2 is arranged in the heating copper plate, and an inlet and outlet of the heating pipe 2 are connected to the heating circulation assembly.

[0009] Further preferably, the printing forming chamber includes a stainless steel plate, a second heat insulation plate and a heating wall which are arranged in sequence from the outside to the inside, a heating pipe is arranged in the heating wall, and an inlet and outlet of the heating pipe are connected to a heating circulation component.

[0010] Further preferably, the heating circulation component includes a circulation pump, an electric water heater and a pipeline pump. The circulation pump and the electric water heater are connected. One end of the electric water heater has an outlet pipe connected to the pipeline pump. A flow regulating valve is provided inside the pipeline pump. The pipeline pump is connected to heating pipeline one and heating pipeline two.

[0011] Further preferably, temperature detection devices are respectively provided at the electric water heater, the inlet and outlet of the heating pipe 2, and the inlet and outlet of the heating pipe 1, and the temperature control system is electrically connected to the temperature detection devices respectively.

[0012] Further preferably, a lifting rod for driving the substrate assembly to rise and fall is provided at the bottom of the printing forming chamber.

[0013] Beneficial effects of the utility model:

[0014] 1) The utility model adopts hot water heating instead of electric heating to reduce safety hazards. At the same time, a heating copper plate is arranged under the substrate, and a heating pipe 2 is arranged in the heating copper plate to directly heat the substrate quickly and evenly. The heat conduction efficiency is higher to maintain the constancy of the temperature of the entire substrate. A heating wall of copper material is also installed in the printing forming room, and a heating pipe 1 is arranged in the heating wall to keep the temperature in the entire printing forming room constant, thereby keeping the printing environment temperature constant.

[0015] 2) The utility model detects the temperature of each flow channel part through the temperature detection device and transmits it to the temperature control system for control. The temperature control system controls the flow regulating valve to adjust the flow until the temperature of the electric water heater, the inner wall of the printing forming chamber and the printer substrate is consistent and stable. The printer starts printing and continuously detects the temperature during the printing process to ensure constant temperature heating.

[0016] The specific implementation of the utility model is further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present invention, but do not constitute a limitation to the present invention. In the accompanying drawings:

[0018] Figure 1 It is a structural schematic diagram of a constant temperature heating system of a substrate and a powder bed based on SLM in the utility model.

[0019] Figure 2 It is a structural schematic diagram of the base plate assembly in the utility model.

[0020] Figure 3 It is a structural schematic diagram of the heating copper plate in the utility model.

[0021] Figure 4 It is a structural schematic diagram of the printing forming chamber in the utility model.

[0022] Figure 5 It is a schematic diagram of the main sectional structure of the printing forming chamber in the utility model.

[0023] Figure 6 It is a schematic diagram of the top view of the main body of the forming chamber in the utility model.

[0024] Figure 7 It is a side structural schematic diagram of the forming chamber main body in the utility model.

[0025] Figure 8 It is a structural schematic diagram of a circulation pump and an electric water heater in the utility model.

[0026] Fig. 9 It is a heating process diagram of the constant temperature heating system of the utility model.

[0027] 1-substrate assembly, 101-printer substrate, 102-heating copper plate, 103-lifting rod, 104-insulation board one, 105-heating pipe two, 2-printing forming chamber, 201-forming chamber body, 201-1-heating wall, 201-2-insulation board two, 201-3-stainless steel plate, 202-pump body pipeline, 203-pipeline pump, 205-heating pipe one, 3-heating circulation assembly, 301-circulation pump, 302-junction box, 303-motor, 304-electric water heater, 4-electric box. DETAILED DESCRIPTION

[0028] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0029] In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0030] In the description of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0031] Please refer to Figure 1-9 , Figure 1It is a schematic diagram of a constant temperature heating system for a substrate and a powder bed based on SLM in the utility model.

[0032] A constant temperature heating system for a substrate and a powder bed based on SLM, comprising a printing forming chamber 2, in which there are a substrate assembly 1 that can be lifted and lowered and a lifting rod 103 that drives the substrate assembly 1 to be lifted and lowered, that is, the substrate assembly 1 and the lifting rod 103 are entirely embedded in the printing forming chamber 2, the substrate assembly 1 can be lifted and lowered in the Z-axis in the inner cavity of the printing forming chamber 2, the printing forming chamber 2 is provided with a heating pipe 1 205, the substrate assembly 1 is provided with a heating pipe 2 105, the heating pipe 1 205 and the heating pipe 2 105 are used to heat the substrate and the powder bed to maintain a constant temperature, a plurality of supporting legs are provided at the bottom end of the printing forming chamber 2 to support the printing forming chamber 2, the constant temperature heating system also comprises a heating circulation assembly 3 and an electrical box 4, the heating circulation assembly 3 is respectively connected to the heating pipe 1 205 and the heating pipe 2 105, to provide constant temperature heated hot water for the heating pipe 1 205 and the heating pipe 2 105, the electrical box 4 contains a temperature control system, and the temperature control system is electrically connected to the heating circulation assembly 3 and all temperature detection devices.

[0033] The temperature control system is an existing technology. The temperature control system is a system for automatically controlling temperature. It can detect the ambient temperature and automatically adjust the temperature to maintain a stable temperature range. This system is used in many industrial production processes to ensure product quality and stability. The temperature control system mainly consists of three parts: temperature sensor, controller and actuator. The temperature sensor is responsible for detecting the ambient temperature and transmitting the detected temperature signal to the controller. After receiving the sensor signal, the controller controls the actuator by calculating and processing the control signal. The function of the actuator is to adjust according to the signal of the controller to achieve the requirements of the stable temperature range. The principle of the temperature control system is: when the ambient temperature reaches the predetermined set value, the temperature sensor will transmit the detected temperature signal to the controller. After calculating and processing the temperature signal, the controller sends an adjustment signal to the actuator. The actuator then adjusts the heating equipment or cooling equipment to keep the temperature within the set range.

[0034] like Figure 2 As shown, the substrate assembly 1 includes a printer substrate 101, a heating copper plate 102 and a heat insulation plate 104 arranged in sequence from top to bottom. Figure 3 As shown, the heating pipe 105 is arranged in the heating copper plate 102, and a temperature detection device is provided at the inlet and outlet of the heating pipe 105 for detecting and controlling the hot water circulation heating. The inlet and outlet of the heating pipe 105 passes through the insulation board 104 and is connected with the heating circulation component 3 through a pipe arranged inside the lifting rod 103. The inlet and outlet of the heating pipe 105 can also directly pass through the insulation board 104 and the printing forming chamber 2 and then be connected with the heating circulation component 3.

[0035] like Figure 4-7 As shown, the forming chamber body 201 of the printing forming chamber 2 includes a stainless steel plate 201-3, a heat insulation plate 201-2 and a heating wall 201-1 of copper material which are arranged in sequence from the outside to the inside. A heating pipe 205 is arranged in the heating wall 201-1, and a temperature detection device is also provided at the inlet and outlet of the heating pipe 205. The inlet and outlet of the heating pipe 205 are connected to the heating circulation component 3. The forming chamber body 201 of the printing forming chamber 2 seals the entire heating system through the stainless steel plate 201-3.

[0036] like Figure 8 As shown, the heating circulation component 3 includes a circulation pump 301 and an electric water heater 304, the circulation pump 301 and the electric water heater 304 are connected, the circulation pump 301 has a motor 303 for providing power, the electric water heater 304 has a junction box 302 connected to the power supply, and the electric water heater 304 is also provided with a temperature detection device, one end of the circulation pump 301 is provided with a water inlet for connecting to the water inlet pipe, one end of the electric water heater 304 is provided with a water outlet pipe, and the other end of the water outlet pipe is connected to the set pipeline pump 203, and the pipeline pump 203 is provided with a flow regulating valve inside. The pump 203 is connected to the heating pipe 1 205 and the heating pipe 2 105 through the pump body pipe 202 respectively, and the hot water heated by the electric water heater 304 is transported to the heating pipe 1 205 and the heating pipe 2 105 for constant temperature heating of the substrate and the powder bed. The pump body can be additionally connected to the outlets of the heating pipe 1 205 and the heating pipe 2 105 to transport the refluxed water to the circulation pump 301 through the pipe. At the same time, the water at the outlets of the heating pipe 1 205 and the heating pipe 2 105 can also be directly discharged. The water inlet of the circulation pump 301 is also connected to a water source.

[0037] The working principle of the utility model is as follows: Fig. 9 As shown, the device is mainly operated by the temperature control system in the electrical box 4. First, the printer starts to preheat. The temperature control system will open the flow regulating valve to an initial flow rate according to the preset temperature, so that the fluid starts to flow in the embedded pipe. After the liquid flows back to the circulation pump 301, the electric water heater 304 starts to heat. At this time, the temperature controller starts to detect the temperature of each flow channel. If the temperature is inconsistent or does not reach the preset temperature, the flow rate is adjusted until the temperature of the electric water heater 304, the inner wall of the printing forming chamber 2 and the printer substrate 101 is consistent and stable. The printer starts printing and continuously detects the temperature during the printing process to ensure constant temperature heating.

[0038] In summary, although the present invention has been disclosed as above in terms of preferred embodiments, the above preferred embodiments are not intended to limit the present invention. A person skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be based on the scope defined in the claims.

Claims

1. A constant temperature heating system for a substrate and a powder bed based on SLM, characterized in that: The invention comprises a printing forming chamber (2), wherein a liftable substrate assembly (1) is provided in the printing forming chamber (2), wherein the printing forming chamber (2) is provided with a heating pipe 1 (205), wherein the substrate assembly (1) is provided with a heating pipe 2 (105), and wherein the constant temperature heating system further comprises a heating circulation assembly (3) and a temperature control system, wherein the temperature control system is electrically connected to the heating circulation assembly (3), wherein the heating circulation assembly (3) is respectively connected to the heating pipe 1 (205) and the heating pipe 2 (105), and is used for providing hot water heated at a constant temperature to the heating pipe 1 (205) and the heating pipe 2 (105).

2. The constant temperature heating system for substrate and powder bed based on SLM according to claim 1, characterized in that: The substrate assembly (1) comprises a printer substrate (101), a heating copper plate (102) and a heat insulation plate 1 (104) which are arranged in sequence from top to bottom; the heating pipe 2 (105) is arranged in the heating copper plate (102); and the inlet and outlet of the heating pipe 2 (105) are connected to the heating circulation assembly (3).

3. The constant temperature heating system for substrate and powder bed based on SLM according to claim 1, characterized in that: The printing forming chamber (2) comprises a stainless steel plate (201-3), a second heat insulation plate (201-2) and a heating wall (201-1) which are arranged in sequence from the outside to the inside; the heating pipe (205) is arranged in the heating wall (201-1); and the inlet and outlet of the heating pipe (205) are connected to the heating circulation component (3).

4. The constant temperature heating system for substrate and powder bed based on SLM according to claim 1, characterized in that: The heating circulation component (3) comprises a circulation pump (301), an electric water heater (304) and a pipeline pump (203); the circulation pump (301) is connected to the electric water heater (304); one end of the electric water heater (304) is provided with a water outlet pipeline connected to the pipeline pump (203); a flow regulating valve is provided inside the pipeline pump (203); and the pipeline pump (203) is respectively connected to the heating pipeline 1 (205) and the heating pipeline 2 (105).

5. The constant temperature heating system for substrate and powder bed based on SLM according to claim 4, characterized in that: Temperature detection devices are respectively provided at the electric water heater (304), the inlet and outlet of the second heating pipe (105), and the inlet and outlet of the first heating pipe (205), and the temperature control system is electrically connected to the temperature detection devices.

6. The constant temperature heating system for substrate and powder bed based on SLM according to claim 1, characterized in that: A lifting rod (103) connected to the substrate assembly (1) is provided at the bottom of the printing and forming chamber (2) and is used to drive the substrate assembly (1) to rise and fall.

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