Rapid temperature acquisition system and method in casting solidification process

Abstract

The invention discloses a casting solidification process temperature rapid acquisition system and method, and relates to the casting solidification field, the casting solidification process temperature rapid acquisition system comprises a plurality of temperature acquisition units, each temperature acquisition unit comprises a thermocouple, an insulation tube, a temperature controllable heating rod and a data acquisition unit, the insulation tube is installed outside the thermocouple, the heating rod is installed outside the insulation tube, and the data acquisition unit is connected with the thermocouple. The measuring end of the thermocouple extends out of the end parts of the insulating tube and the heating rod, and the thermocouple is connected with a data acquisition unit and is used for acquiring temperature information and sending a temperature signal to the data acquisition unit; the heating rod penetrates through the casting mold so that the measuring end of the thermocouple can stretch into an inner cavity of the casting mold. The temperature change condition of the casting in the whole solidification process can be measured timely and accurately, and the solidification temperature curve collection problem of the casting in the liquid stage is solved.

Description

Technical Field

[0001] The present application belongs to the technical field of casting solidification, and in particular relates to a system and method for quickly collecting the temperature of a casting solidification process. Background Art

[0002] During the solidification process of castings, there are differences in the temperature change curves of different parts. Changes in solidification temperature directly affect the control of solidification structure, thereby affecting the quality of castings. Generally, a thermocouple is embedded in the cavity to collect the temperature of the target position at different times during the solidification process, and finally form a solidification temperature curve. However, the melt temperature is high and the cavity temperature is low. The thermocouple cannot quickly rise from the cavity temperature to the melt temperature, so it is impossible to accurately collect the temperature change curve of the initial solidification, especially the liquid part. It takes 20 seconds for most areas of the casting to solidify from the liquid to the solid stage. The commonly used thermocouple takes about 15 seconds to heat up from room temperature to 700°C, which is very unfavorable for the temperature collection of the solidification process of the casting, and it is impossible to obtain the temperature change curve of the liquid stage such as the shrinkage compensation process and grain growth. Summary of the invention

[0003] The technical problem solved by the present application is: to overcome the deficiencies of the prior art, to provide a system and method for quickly collecting the temperature of a casting during solidification, to timely and accurately measure the temperature changes of the casting during the entire solidification process, and to solve the problem of collecting the solidification temperature curve of the casting in the liquid stage.

[0004] The technical solutions provided by this application are as follows:

[0005] In a first aspect, a system for rapidly collecting the temperature of a casting during solidification is provided, comprising a plurality of temperature collection units, each of which comprises a thermocouple, an insulating tube, a temperature-controllable heating rod and a data collector, the insulating tube being installed outside the thermocouple, the heating rod being installed outside the insulating tube, the measuring end of the thermocouple protruding from the ends of the insulating tube and the heating rod, the thermocouple being connected to the data collector, the thermocouple being used to collect temperature information and send temperature signals to the data collector; the heating rod passing through the casting mold so that the measuring end of the thermocouple extends into the inner cavity of the casting mold.

[0006] In one possible implementation of the rapid temperature acquisition system, the measuring end of the thermocouple protrudes 2 mm to 3 mm out of the insulating tube.

[0007] In one possible implementation of the rapid temperature acquisition system, the insulating tube is a quartz tube and / or a ceramic tube.

[0008] In one possible implementation of the rapid temperature acquisition system, the heating rod includes a cylindrical steel pipe and a heating wire, the heating wire is installed on the inner wall of the steel pipe, and the insulating tube and the thermocouple are installed in the steel pipe.

[0009] In one implementable method of the rapid temperature acquisition system, the casting mold arranges multiple groups of metal detection wires around each temperature acquisition unit, each group of metal detection wires includes a first detection wire and a second detection wire, and the multiple groups of metal detection wires are connected to a power supply and a controller. When the molten metal touches a group of metal detection wires, the first detection wire and the second detection wire are conductive. After the controller receives the conductive signal of any group of metal detection wires around the temperature acquisition unit, it controls the heating rod to stop heating.

[0010] In one possible implementation of the rapid temperature acquisition system, each group of metal detection lines is 10 mm to 20 mm away from the heating rod.

[0011] In one possible implementation of the temperature rapid acquisition system, when the casting material is sand, a plurality of protrusions are provided on the outer wall of the heating rod, and the protrusions are embedded in the casting made of sand during the casting process.

[0012] When the casting material is metal or ceramic, the casting is provided with a mounting hole at a preset temperature detection position, and the temperature acquisition unit is extended into the inner cavity of the casting through the mounting hole. A fixing device is provided between the temperature acquisition unit and the casting to fix the relative position of the temperature acquisition unit and the casting.

[0013] In one possible implementation of the rapid temperature acquisition system, the fixing device includes a plug block. After the temperature acquisition unit extends from the mounting hole into a preset detection position in the inner cavity of the casting mold, the plug block is inserted between the inner wall of the mounting hole and the temperature acquisition unit and pressed tightly.

[0014] In a second aspect, a method for quickly collecting the temperature of a casting during solidification is provided, comprising:

[0015] Pre-embed the temperature acquisition unit and metal detection wire into the casting mold;

[0016] Connect the thermocouple to the data logger through the compensation wire, and connect the metal detection wire to the power supply, controller and heating rod;

[0017] Turn on the heating rod to heat the thermocouple to the pouring temperature of the molten metal and maintain this temperature;

[0018] The molten metal is poured into the mold. When the molten metal touches any set of metal detection wires, the metal detection wires are turned on. After the controller receives the metal detection wire conduction signal, it controls the heating rod to cut off the power and stop heating, and starts to measure the solidification temperature of the casting.

[0019] In summary, this application at least includes the following beneficial technical effects:

[0020] The casting solidification process temperature rapid acquisition system of the method can rapidly acquire the casting melt temperature during rapid temperature drop by preheating the thermocouple online, thereby achieving comprehensive measurement of the solidification temperature curve during the casting solidification process. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is the structural diagram of the temperature acquisition unit;

[0022] Figure 2 A partial cross-sectional view of the temperature acquisition unit.

[0023] Explanation of the accompanying drawings: 1. Thermocouple; 2. Insulating tube; 3. Ring heating rod; 31. Heating wire; 32. Ring tube; 4. Double-hole insulating porcelain tube. DETAILED DESCRIPTION

[0024] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments disclosed in the present invention will be further described in detail below with reference to the accompanying drawings.

[0025] The present application embodiment discloses a system for rapidly collecting the temperature of a casting solidification process. Figure 1 As shown, it includes multiple temperature acquisition units, each of which includes a thermocouple 1, an insulating tube 2, a temperature-controllable annular heating rod 3, a double-hole insulating porcelain tube 4, a metal detection line, and a data collector.

[0026] Different types of thermocouples 1 are selected according to the different materials of the castings. K type is generally used for aluminum alloys.

[0027] Thermocouple 1 is connected to the data collector through a compensation wire, and the data collector completes the collection, recording and output of temperature data.

[0028] The thermocouple 1 includes two thermocouples, one end of which is connected and the other end of which passes through two holes of a double-hole insulating porcelain tube 4 and then passes through the insulating tube 2.

[0029] The insulating tube 2 is cylindrical in shape and wraps the thermocouple 1 and the compensation wire. The insulating tube 2 is generally made of a quartz tube and / or a ceramic tube. The measuring end of the thermocouple 1 protrudes from the end of the insulating tube 2 by 2mm-3mm.

[0030] like Figure 2 As shown, the annular heating rod 3 is a hollow structure. The annular heating rod 3 includes two cylindrical inner and outer annular tubes 32 and a heating wire 31. The heating wire is installed between the two annular tubes, and one end of the two annular tubes is fixedly connected to an end plate. The middle of the end plate has a through hole for the thermocouple 1 to pass through. The other ends of the two annular tubes are closed. The space between the two annular tubes is also filled with magnesium oxide powder to isolate the heating wire from the annular tubes, which plays an insulating and heat-conducting role. The inner diameter of the annular heating tube deviates from the outer diameter of the insulating tube by 0.5mm-2mm. The insulating tube 2 and the thermocouple 1 are combined and arranged in the annular heating rod 3. The measuring end of the thermocouple 1 protrudes 2mm-3mm from the steel pipe.

[0031] In addition, multiple groups of metal detection wires are arranged around the annular heating rod 3. Each group of metal detection wires includes a first detection wire and a second detection wire. When the metal liquid touches a group of metal detection wires, the first detection wire and the second detection wire are connected, and the controller controls the annular heating rod 3 to stop heating. The distance between each group of metal detection wires and the annular heating rod 3 is generally 10 mm to 20 mm.

[0032] like Figure 2 As shown, the temperature acquisition unit is embedded in the mold, and the mold material is metal, ceramic or sand, etc. The measuring end of the thermocouple 1 extends into the inner cavity of the mold, and the depth of the measuring end of the thermocouple 1 extending into the inner cavity of the mold is determined according to the position where the temperature measurement is required. When the mold material is sand, the outer wall of the annular heating rod 3 is provided with a plurality of protrusions, and the protrusions will be embedded in the mold of the sand material during the mold forming process to ensure that the temperature acquisition unit can be embedded in the mold in a stable position. When the mold material is metal or ceramic, the mold is provided with a mounting hole at a preset temperature detection position, and the temperature acquisition unit is extended into the inner cavity of the mold from the mounting hole. In order to fix the position between the temperature acquisition unit and the mold, and to avoid the temperature acquisition unit being disturbed and moved, resulting in inaccurate detection position, a fixing device needs to be provided between the temperature acquisition unit and the mold. There are many possible implementation modes for the fixing device. In the first one, the fixing device includes a plug block, which may be wedge-shaped. When the temperature acquisition unit extends from the mounting hole into a preset detection position in the inner cavity of the casting, the plug block is inserted between the inner wall of the mounting hole and the temperature acquisition unit, and the plug block is pressed. At this time, the relative position between the temperature acquisition unit and the casting is fixed.

[0033] The outer wall of the annular heating rod 3 is provided with engraved lines, and when the temperature collection unit is pre-buried in the casting mold, the embedding depth can be precisely controlled according to the engraved lines.

[0034] Collection methods include:

[0035] The rapid temperature acquisition system for the solidification process of the casting is embedded in the casting mold. The thermocouple 1 is connected to the data acquisition device through the compensation wire. Before pouring the casting, the annular heating rod 3 is turned on, and the thermocouple 1 is heated to the pouring temperature of the casting and maintained at this temperature. When the casting is poured, the molten metal touches any set of metal detection wires around the annular heating rod 3, and the annular heating rod 3 is powered off, the heating is stopped, and the solidification temperature measurement of the casting is started until the casting solidifies to the specified temperature, and the measurement task is completed.

[0036] The contents not described in detail in this application specification belong to the common knowledge of those skilled in the art.

[0037] The present application is described in detail above in conjunction with specific implementation methods and exemplary examples, but these descriptions cannot be understood as limiting the present application. Those skilled in the art understand that, without departing from the spirit and scope of the present application, a variety of equivalent replacements, modifications or improvements can be made to the technical solution of the present application and its implementation methods, all of which fall within the scope of the present application. The scope of protection of the present application shall be subject to the attached claims.

Claims

1. A system for rapidly collecting temperature during the solidification process of a casting, characterized by: The invention comprises a plurality of temperature acquisition units, each of which comprises a thermocouple (1), an insulating tube (2), a temperature-controllable annular heating rod (3) and a data collector. The insulating tube (2) is installed outside the thermocouple (1), the annular heating rod (3) is installed outside the insulating tube (2), the measuring end of the thermocouple (1) protrudes from the ends of the insulating tube (2) and the annular heating rod (3), the thermocouple (1) is connected to the data collector, and the thermocouple (1) is used to collect temperature information and send a temperature signal to the data collector; the annular heating rod (3) passes through the casting mold so that the measuring end of the thermocouple (1) protrudes into the inner cavity of the casting mold.

2. A casting solidification process temperature rapid acquisition system according to claim 1, characterized in that: The measuring end of the thermocouple (1) protrudes 2 mm to 3 mm from the insulating tube (2).

3. A casting solidification process temperature rapid acquisition system according to claim 1, characterized in that: The insulating tube (2) is made of a quartz tube and / or a ceramic tube.

4. A casting solidification process temperature rapid acquisition system according to claim 1, characterized in that: The annular heating rod (3) comprises two layers of inner and outer annular tubes (32) and a heating wire (31). One end of the two annular tubes (32) is fixedly connected to an end plate. The middle of the end plate has a through hole for the thermocouple (1) to pass through. The other ends of the two annular tubes (32) are sealed. The heating wire is installed in the two layers of annular tubes (32). The space between the two annular tubes (32) is also filled with magnesium oxide powder. The insulating tube (2) and the thermocouple (1) are installed in the annular heating rod (3).

5. The system for rapidly collecting temperature during solidification of casting according to claim 1, characterized in that: The casting mold arranges multiple groups of metal detection wires around each temperature collection unit, each group of metal detection wires includes a first detection wire and a second detection wire, and the multiple groups of metal detection wires are connected to a power supply and a controller. When the molten metal touches a group of metal detection wires, the first detection wire and the second detection wire are connected. After the controller receives a conduction signal from any group of metal detection wires around the temperature collection unit, it controls the annular heating rod (3) to stop heating.

6. A system for rapidly collecting temperature during solidification of castings according to claim 5, characterized in that: Each group of metal detection lines is 10 mm to 20 mm away from the annular heating rod (3).

7. The system for rapidly collecting temperature during solidification of casting according to claim 1, characterized in that: When the casting material is sand, the outer wall of the annular heating rod (3) is provided with a plurality of protrusions, and the protrusions are embedded in the casting material of the sand during the casting process.

8. The system for rapidly collecting temperature during solidification of casting according to claim 1, characterized in that: When the casting material is metal or ceramic, the casting is provided with a mounting hole at a preset temperature detection position, and the temperature acquisition unit is extended into the inner cavity of the casting through the mounting hole. A fixing device is provided between the temperature acquisition unit and the casting to fix the relative position of the temperature acquisition unit and the casting.

9. A system for rapidly collecting temperature during solidification of casting according to claim 1, characterized in that: It also includes a double-hole insulating porcelain tube (4), and the thermocouple (1) includes two thermocouples, one end of which is connected and the other end of which passes through two holes of the double-hole insulating porcelain tube (4) and then passes through the insulating tube (2).

10. A method for collecting temperature of a casting solidification process rapid collection system according to any one of claims 1 to 9, characterized in that: include: Pre-embed the temperature acquisition unit and metal detection wire into the casting mold; Connecting the thermocouple (1) to the data acquisition device via a compensation wire, and connecting the metal detection wire to the power supply, the controller and the annular heating rod (3); The annular heating rod (3) is turned on to heat the thermocouple (1) to the pouring temperature of the molten metal and maintain the temperature; the molten metal is poured into the casting mold, and after the molten metal touches any set of metal detection wires, the metal detection wires are turned on, and after the controller receives the metal detection wire turn-on signal, it controls the annular heating rod (3) to cut off the power and stop heating, and starts to measure the solidification temperature of the casting.

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