A temperature control method for deep hole hot extrusion die

Abstract

The present invention discloses a temperature control method for a deep-hole hot extrusion die, comprising injecting a heated oil medium into the oil circuits of an upper die and a lower die through a die temperature controller for preheating; the die temperature controller continues to heat the oil medium to a set temperature, allowing the oil medium to circulate in the oil circuit; after the upper die and the lower die reach the working temperature through monitoring by a thermocouple sensor, the upper and lower dies are closed; when the working temperature reaches the set temperature, the die temperature controller lowers the temperature of the oil medium in the oil circuits of the upper die and the lower die, regulating the circulating flow of the oil medium in the oil circuit; after production is completed, the die temperature controller lowers the temperature of the oil medium in the oil circuit, and cools the upper and lower dies. The present invention regulates the temperature and flow of the oil medium through the die temperature controller, utilizes heat transfer of the oil medium to regulate the die temperature, and the die temperature is monitored in real time by a thermocouple sensor, which feeds back the monitoring data to the die temperature controller. The entire process forms a closed loop for precise temperature control, ensuring that the die is always in the most suitable working temperature range.

Description

Technical Field

[0001] The invention relates to the technical field of deep hole extrusion die temperature control, and in particular to a deep hole hot extrusion die temperature control method. Background Art

[0002] The optimal working temperature of metal hot extrusion dies generally has a specific temperature range, so the die needs to be preheated before production begins in order to avoid die sticking or a large temperature drop due to a large temperature difference between the die and the blank, which affects the quality of the product.

[0003] During the extrusion process of deep-hole hot extrusion dies, heat transfer between the billet and the die causes the die temperature to rise, necessitating die cooling. Failure to promptly reduce the die temperature can lead to annealing failure, resulting in substandard products and mold scrapping. During the extrusion of large metal billets, the billet and die typically conduct heat in contact. Because the contact time, contact area, and degree of deformation vary across different parts of the billet, temperature differences can occur across the die, necessitating timely temperature control.

[0004] Therefore, it is difficult to achieve efficient and uniform mold preheating and effective temperature control during mold operation using existing mold preheating and mold temperature control methods during part processing. Summary of the Invention

[0005] The purpose of the present invention is to provide a deep hole hot extrusion die temperature control method to solve the technical problem in the prior art that due to the large volume and weight of the existing metal hot extrusion die, it is difficult to achieve efficient and uniform preheating and effective temperature control during the die working process using the existing die preheating and part processing methods.

[0006] In order to solve the above technical problems, the present invention specifically provides the following technical solutions:

[0007] A method for controlling the temperature of a deep hole hot extrusion die comprises the following steps:

[0008] Step 100: An oil circuit is provided in both the upper and lower dies of the deep hole extrusion die, and the inlet and outlet ends of the oil circuit are connected to a mold temperature controller so that the oil circuits in the upper and lower dies can form a closed-loop oil circuit;

[0009] Step 200: In the oil circulation state of the open oil circuit, the heated oil medium is injected into the oil circuits of the upper mold and the lower mold through the mold temperature controller to preheat the mold;

[0010] Step 300: Continue heating the oil medium in the oil circuits of the upper mold and the lower mold by the mold temperature controller until the oil medium reaches a set working temperature, so that the oil medium circulates in the oil circuit;

[0011] Step 400: After the upper mold and the lower mold reach the operating temperature through monitoring by the thermocouple sensor, the upper mold and the lower mold begin to close the mold to extrude the metal billet;

[0012] Step 500: The real-time temperature of the mold is obtained by thermocouples installed in the upper mold and the lower mold. When the mold operating temperature reaches a set threshold temperature, the mold temperature controller begins to reduce the temperature of the oil medium in the oil circuit of the upper mold and the lower mold, and adjusts the circulation flow rate of the oil medium in the oil circuit to cool the upper and lower molds through the oil medium.

[0013] Step 600: After the upper and lower molds have completed demolding and closing the molds to produce the set number of parts, the mold temperature controller lowers the temperature of the oil medium in the oil circuit to the set cooling temperature, so that the oil medium in the oil circuit exchanges heat with the upper and lower molds to cool the upper and lower molds.

[0014] As a preferred solution of the present invention, in the state where the oil circuit is open, the oil circuit operation detection of the upper mold and the lower mold is carried out, and the specific method is as follows:

[0015] The mold temperature controller adjusts the pressure of the oil medium in the oil circuit to 0.3Mpa, the temperature of the oil medium is room temperature, and the oil medium circulates in the oil circuit for ten minutes. Then the mold temperature controller adjusts the temperature of the oil medium in the oil circuit to the first target temperature, which is set to 80°C, and detects the pressure state of the oil medium in the oil circuit.

[0016] As a preferred solution of the present invention, when the oil medium pressure in the oil circuit is stable, the oil medium is heated at 2°C / min until the oil medium reaches a set working temperature, and the set working temperature of the oil medium is 300°C.

[0017] As a preferred solution of the present invention, the mold temperature controller controls the circulation flow rate of the oil circuit of the upper mold and the lower mold to be 20 L / min when the oil medium temperature is 300°C.

[0018] As a preferred embodiment of the present invention, when the working temperature of the upper mold and the lower mold reaches the threshold temperature, the specific method for the mold temperature controller to start lowering the temperature of the oil medium in the oil circuit includes:

[0019] The temperature rise state parameters of the upper die and the lower die under different initial temperatures of the metal blank and the working cycle time of the upper die and the lower die in a single mold closing are obtained by thermocouples;

[0020] When the working temperature of the upper mold and the lower mold reaches the third target temperature, the mold temperature controller reduces the temperature of the oil medium injected into the oil circuit according to the temperature increase state parameter.

[0021] As a preferred solution of the present invention, the threshold temperature reached by the working temperature of the upper mold and the lower mold is set to 350°C, and the mold temperature controller reduces the temperature of the oil medium injected into the oil circuit to 120°C.

[0022] As a preferred embodiment of the present invention, the oil passage apertures in the upper and lower dies and the oil medium circulation flow rate of the oil passages are determined according to the outer diameter, inner diameter, inner hole depth and total height of the product extruded from the metal billet.

[0023] As a preferred solution of the present invention, the oil medium circulation flow rate in the oil circuit of the upper mold is 20 L / min, and the oil medium circulation flow rate in the oil circuit of the lower mold is 40 L / min.

[0024] As a preferred solution of the present invention, different independently controlled closed circulation oil circuits are divided according to the number of inner and outer layers of the lower mold and the shape of the mold cavity, specifically including:

[0025] An independent closed-circulation oil circuit is provided on the contact surface of the inner and outer layers of the lower die;

[0026] An independent closed-circulation oil circuit is set in the part with the same inner diameter of the mold cavity;

[0027] An independent closed circulation oil circuit is provided in the layer structure portion where the inner diameter of the mold cavity changes continuously.

[0028] As a preferred embodiment of the present invention, the mold further comprises a medium supply device, a pressure relief device, a pressurizing device, and a medium pipeline arranged in the mold, wherein the medium pipeline has a pipeline inlet and a pipeline outlet, the outlet end of the medium supply device is connected to the pipe inlet, and the inlet end of the medium supply device is connected to the pipeline outlet, forming a medium closed circulation loop, the pressure relief device is connected to the pipeline between the inlet end of the medium supply device and the pipeline outlet via a three-way valve; the pressurizing device is connected to the pipeline between the outlet end of the medium supply device and the pipe inlet;

[0029] Wherein, the medium with a temperature of 80° is injected into the medium pipeline through the medium supply device to preheat the mold;

[0030] When the oil medium in the mold oil circuit reaches the set working temperature, the medium in the medium pipeline is heated to 120° C. by using the booster device to boost the pressure of the medium closed circulation pipeline, and the medium circulation of the medium closed circulation pipeline is opened;

[0031] When the upper and lower dies begin to close and the metal blank is extruded, the pressure relief device is opened, the pipeline between the medium supply device and the inlet end and the pipeline outlet is closed, and the pressurizing device is turned off; at this time, the medium supply device delivers a medium at a temperature of 80° C. into the medium pipeline;

[0032] When the working temperature of the mold reaches a set threshold temperature, the temperature of the medium supplied by the medium supply device to the medium pipeline is reduced at a rate of 1°C / min until the temperature of the mold reaches the set working temperature.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] The mold temperature control method provided by the present invention adopts high-temperature resistant oil as the heat transfer medium, and heats and cools the high-temperature resistant oil in different stages through a mold temperature controller. The oil medium circulates in the closed oil circuit of the upper mold and the lower mold, and the mold temperature is increased by heat conduction between the oil and the mold. During the production process, the oil temperature is monitored in real time, the mold oil temperature is adjusted, and it is determined whether the mold is overheated. The mold temperature is lowered through heat conduction between the oil medium and the mold to ensure that the mold is always in the most suitable working temperature range. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are merely exemplary, and those skilled in the art can derive other implementation drawings based on the provided drawings without inventive effort.

[0036] Figure 1 Schematic diagram of the control method flow in an embodiment of the present invention;

[0037] Figure 2 Schematic diagram of the oil circuits and oil inlet and outlet distribution in the upper and lower molds according to an embodiment of the present invention;

[0038] Figure 3 Schematic diagram of the distribution of the medium pipeline, pipeline inlet, and pipeline outlet in the upper mold according to an embodiment of the present invention;

[0039] Figure 4 For the embodiment of the present invention Figure 4 Schematic diagram of the oil circuit structure set in the upper and lower molds of the mold.

[0040] The numbers in the figure represent the following:

[0041] 1-Oil outlet of lower die; 2-Oil inlet of lower die; 3-Oil outlet of upper die; 4-Oil inlet of upper die; 5-Medium pipeline; 6-Medium supply device; 7-Pressure booster; 8-Pressure relief device; 9-Three-way valve; 10-Oil circuit; 11-Upper die base; 12-Lower die; 13-Upper die; 14-Intermediate fixing part. DETAILED DESCRIPTION

[0042] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0043] The metal hot extrusion die involved in this real-time method is large in size and weight, and it is difficult to achieve efficient and uniform preheating using conventional preheating methods.

[0044] The optimal working temperature of metal hot extrusion dies is around 300°C, so the dies need to be preheated before production begins in order to avoid die sticking or a large temperature drop due to a large temperature difference between the dies and the blank. During the extrusion production process, the die temperature rises due to heat conduction between the blank and the die, and the die needs to be cooled. If the die temperature cannot be lowered in time, the die annealing will fail, resulting in unqualified products and die scrapping.

[0045] Large, deep-hole parts have diverse shapes and material properties. During the extrusion process, the billet and the die are in contact and heat transfer. Since the contact time, contact area, and degree of deformation of each part of the billet with the die vary, there will be temperature differences between different parts of the die, requiring timely temperature control.

[0046] For this reason, Figure 1 and Figure 2 As shown, the present invention provides a deep hole hot extrusion die temperature control method, comprising the following steps:

[0047] Step 100: An oil circuit is provided in both the upper and lower dies of the deep hole extrusion die, and the inlet and outlet ends of the oil circuit are connected to a mold temperature controller so that the oil circuits in the upper and lower dies can form a closed-loop oil circuit;

[0048] Step 200: In the oil circulation state of the open oil circuit, the heated oil medium is injected into the oil circuits of the upper mold and the lower mold through the mold temperature controller to preheat the mold;

[0049] Step 300: Continue heating the oil medium in the oil circuits of the upper mold and the lower mold by the mold temperature controller until the oil medium reaches a set working temperature, so that the oil medium circulates in the oil circuit;

[0050] Step 400: After the upper mold and the lower mold reach the operating temperature through monitoring by the thermocouple sensor, the upper mold and the lower mold begin to close the mold to extrude the metal billet;

[0051] Step 500: The real-time temperature of the mold is obtained by thermocouples installed in the upper mold and the lower mold. When the mold operating temperature reaches a set threshold temperature, the mold temperature controller begins to reduce the temperature of the oil medium in the oil circuit of the upper mold and the lower mold, and adjusts the circulation flow rate of the oil medium in the oil circuit to cool the upper and lower molds through the oil medium.

[0052] Step 600: After the upper and lower molds have completed demolding and closing the molds to produce the set number of parts, the mold temperature controller lowers the temperature of the oil medium in the oil circuit to the set cooling temperature, so that the oil medium in the oil circuit exchanges heat with the upper and lower molds to cool the upper and lower molds.

[0053] In this embodiment, an oil circuit capable of forming a closed oil medium circulation is provided in both the upper and lower dies of the deep hole hot extrusion die. By connecting the oil inlet and the oil outlet of the oil circuit to the mold temperature controller, the circulation of the medium in the oil circuit is realized, thereby enabling the temperature control of the upper and lower dies of the die to be realized. The temperature of the die is dynamically controlled, which solves the problem of die preheating before extrusion and the problem of die cooling during extrusion, thereby greatly improving the quality of forgings and the life of the die and reducing production costs.

[0054] In the oil circuit of this embodiment, high temperature resistant oil is used as the heat transfer medium, and the high temperature resistant oil is heated by the mold temperature controller.

[0055] Taking into account the different shapes of hot extruded parts, the differences in material properties, and the requirements for mold design and structural strength, different oil circuits are set in different areas of the mold, and the oil circuits in each area can be controlled separately.

[0056] The diameter of the oil circuit, the density of the layout and the direction can be modified during mold production according to actual needs.

[0057] The oil circulates in the mold oil circuit, and the mold temperature is increased through heat conduction between the oil and the mold. During the production process, the oil temperature is monitored in real time by several thermocouples distributed in the oil circuit. After feedback is sent to the mold temperature controller, temperature adjustments are made. The oil circuit connectivity, flow rate and oil temperature of each part of the mold are adjusted to determine whether the mold is overheated. The mold temperature is lowered by the mold temperature controller, and the mold temperature is lowered through heat conduction between the oil and the mold to ensure that the mold is always in the most suitable operating temperature range.

[0058] The spiral oil circuit in the upper die increases the contact area between the die and the oil without weakening the die strength. The cross-sectional area and pitch density of the spiral oil circuit can be tailored to the inner surface characteristics and material temperature characteristics of large deep-hole parts for targeted processing, keeping the upper die temperature within a reasonable range.

[0059] For example, the head of a certain type of large hot extrusion part deforms violently, causing a rapid temperature rise. This results in a large concentration of heat, which is quickly transferred to the upper die. This requires increasing the diameter of the oil line at the upper die head, tightening the oil line pitch, and temporarily controlling the temperature with a mold temperature controller to increase the flow rate and quickly cool the upper die.

[0060] The lower die of a large hot extrusion die is enormous, and the die design allows for ample strength margins. The inner and outer dies are tightly nested, allowing for more flexible and efficient oil circuit configuration. During part formation, the outer surface of the part contacts the inner wall of the lower die, facilitating rapid heat transfer. The cross-sectional area and layout of the oil circuits are appropriately adjusted. In addition to spiral circuits, the oil circuits can also be arranged in a "U" shape or spirally wound, and these different layouts can be combined. Using a zoning and segmented temperature control method, the mold temperature controller, temperature sensors, and oil circuits with different layouts in each area of the lower die are connected in parallel to precisely control the lower die temperature.

[0061] For example, a certain type of large hot-extruded part has a small head and experiences severe deformation, resulting in a rapid temperature rise during forming. However, due to its large size and length, it cools down slowly after forming. The inner surface of the lower die bottom contacts the outer surface of the part head, utilizing a large cross-sectional area to increase the density of the oil circuits, using a "U" pattern or spiral windings. The tail of the part cools quickly, requiring a slower cooling rate to match that of the head. A spiral oil circuit is used in the area where the lower die contacts the tail, allowing for a more controlled cooling process.

[0062] like Figure 3 、 Figure 4 As shown, in this embodiment, the upper die and lower die suitable for extrusion forming of large metal parts are nested in each other, and the die is assembled by hot pressing to ensure that the oil circuit does not leak, thereby ensuring the strength of the die and reducing the processing difficulty.

[0063] Temperature control oil circuits are designed on both the inner and outer layers of the mold. Without affecting the structural strength of the mold, the width, shape and reflux path of the oil circuits vary according to the different shapes of metal parts and the different temperature control requirements of different parts.

[0064] Different oil circuits are designed for different areas of the mold based on the shape and material properties of the machined parts at different temperatures, achieving differentiated mold temperature control. This ensures the yield of hot extrusion while mitigating the drawback of shortening the mold's service life due to drastic temperature fluctuations caused by heat conduction.

[0065] Specifically, with the oil circuit open, perform oil circuit operation inspection on the upper and lower dies. The specific method is as follows:

[0066] The mold temperature controller adjusts the pressure of the oil medium in the oil circuit to 0.3Mpa, the temperature of the oil medium is room temperature, and the oil medium circulates in the oil circuit for ten minutes. Then the mold temperature controller adjusts the temperature of the oil medium in the oil circuit to the first target temperature, which is set to 80°C, and detects the pressure state of the oil medium in the oil circuit.

[0067] When the oil medium pressure in the oil circuit is stable, the oil medium is heated at 2°C / min until the temperature of the oil medium reaches a second target temperature, which is set to 300°C.

[0068] The mold temperature controller controls the circulation flow rate of the oil circuit of the upper mold and the lower mold at 20L / min when the oil medium temperature is 300℃.

[0069] When the working temperature of the upper mold and the lower mold reaches the third target temperature, the mold temperature controller starts to reduce the temperature of the oil medium in the oil circuit. The specific method includes:

[0070] The temperature rise state parameters of the upper and lower dies under different initial temperatures of the metal blank and the working cycle time of the upper and lower dies in a single mold closing are obtained through thermocouples.

[0071] When the working temperature of the upper mold and the lower mold reaches the third target temperature, the mold temperature controller reduces the temperature of the oil medium injected into the oil circuit according to the temperature increase state parameter.

[0072] This embodiment can monitor the temperature of the mold in real time by detecting the temperature of the oil inlet and outlet of the oil circuit, forming visual data, which is of great significance for the prediction of mold life and product qualification rate.

[0073] The third target temperature reached by the working temperature of the upper mold and the lower mold is set to 350°C, and the mold temperature controller reduces the temperature of the oil medium injected into the oil circuit to 120°C.

[0074] The mold temperature controller lowers the temperature of the oil medium in the oil circuit to a fourth target temperature, and the fourth target temperature is set to 20°C.

[0075] In this embodiment, the oil passage apertures in the upper and lower dies and the oil medium circulation flow rate of the oil passages are determined based on the outer diameter, inner diameter, inner hole depth, and total height of the product extruded from the metal billet, as specifically described in the following embodiment:

[0076] Step 1: First, connect the mold temperature controller to the oil circuits of the upper and lower molds, and adjust the oil outlet pressure to 0.3 MPa. Let the oil circulate in the oil circuit for 10 minutes to test the operation of the mold temperature controller and oil leakage in the oil circuit.

[0077] Step 2: Raise the oil temperature to 80°C and check the stability of the oil pressure in the oil circuit. If the oil pressure in the oil circuit remains stable, increase the temperature of the mold temperature controller at 2°C / min until the oil temperature reaches 300°C.

[0078] Step 3: Open the control valve of the oil circuit, and the oil circulates in the oil circuit. The upper oil circuit circulation flow rate is 20L / min, and the lower oil circuit circulation flow rate is 40L / min;

[0079] Step 4: Observe the thermocouple feedback temperature set on the mold. When the mold temperature reaches 300°C, start hot extrusion of deep-hole cylindrical parts without stopping the mold temperature controller.

[0080] Step 5: After hot extruding a metal billet, the die temperature reaches 437°C. The oil temperature at the oil inlet of the oil circuit is reduced to 120°C. The temperature of the upper and lower dies is reduced to 350°C within 2 minutes, which is within the optimal working temperature range of the die.

[0081] Step 6: The hot extrusion cycle is 5 minutes per piece. The oil temperature is always maintained at 120°C, which can ensure that the mold temperature is always between 300 and 350°C, and continuous and stable production can be achieved.

[0082] Step 7: After producing a batch of 50 pieces, the oil temperature is adjusted to 20°C, the mold temperature is reduced to 100°C within 5 minutes, the oil supply is stopped, the valves at the oil inlet and outlet are closed, and the mold is slowly cooled to room temperature.

[0083] The qualified rate of metal extrusion parts produced according to the above method is increased by 10%, and the mold life is increased from 2,500 pieces to 3,000 pieces, which significantly improves the product qualified rate and reduces the mold cost.

[0084] According to the number of inner and outer layers of the lower mold and the shape of the mold cavity, different independently controlled closed circulation oil circuits are divided to Figure 2 、 Figure 4 The lower mold 12 of the mold shown is a column, and the lower mold 12 has an inner and outer layer structure, specifically including:

[0085] A closed-circulation oil circuit is provided on the contact surfaces of the inner and outer structures of the lower mold 12 .

[0086] A closed circulation oil circuit is provided in the layer structure portion with the same inner diameter of the mold cavity.

[0087] A closed circulation oil circuit is arranged in the inner layer structure part where the inner diameter of the mold cavity changes continuously.

[0088] Due to the influence of the mold cavity and the inner and outer layer structures, the existing mold preheating method cannot ensure that the inner and outer layers of the mold obtain a consistent preheating temperature. Therefore, during the hot extrusion molding process, the temperature change between the inner and outer layers is difficult to clearly know and accurately control.

[0089] like Figure 3 and Figure 4 As shown, in this embodiment, the upper mold 13 is installed on the upper mold base 11, and no oil circulation is set in the upper mold base 13. Instead, an intermediate fixing part 14 is set in the middle of the upper mold, and an oil circuit is set in the intermediate fixing part 14 or in the intermediate fixing part 14 and the upper mold 13.

[0090] In this embodiment, the closed circulation oil circuits that can be independently controlled are divided according to the number of inner and outer layers of the mold and the cavity structure. The concave mold suitable for extrusion forming of large metal billets adopts the form of inner and outer layers nested with each other, which ensures the strength of the mold while reducing the processing difficulty.

[0091] Temperature control oil circuits are designed on both the inner and outer layers of the mold. Without affecting the structural strength of the mold, the width, shape and reflux path of the oil circuits are different according to the different shapes of the metal billets and the different temperature control requirements of different parts.

[0092] According to the shape, material properties and other characteristics of the processed parts at different temperatures, different oil circuits are designed for different parts of the die to achieve differentiated mold temperature control.

[0093] Furthermore, since the temperature of the mold is mainly controlled by the temperature of the oil medium in the mold to lower and increase the overall temperature, the cooling process of the mold still depends on the control of the temperature in the oil circuit. Therefore, if the temperature of the oil medium flowing in the mold is simply controlled, then during the process of the mold extruding parts, adjusting the temperature of the oil circuit will cause the temperature distribution in the mold to be uneven in a short period of time, and the extrusion quality of the mold during this temperature control adjustment process will not be high.

[0094] To this end, an auxiliary temperature adjustment control system is introduced in this embodiment, which specifically includes:

[0095] The medium supply device, the pressure relief device, the boosting device and the medium pipeline arranged in the mold, the medium pipeline can be staggered between the oil medium pipeline, that is, the medium pipeline and the oil pipeline are combined, the medium pipeline has a pipeline inlet and a pipeline outlet, the outlet end of the medium supply device is connected to the pipe inlet, and the inlet end of the medium supply device is connected to the pipeline outlet, forming a medium closed circulation loop, the pressure relief device is connected to the pipeline between the inlet end of the medium supply device and the pipeline outlet through a three-way valve; the boosting device is connected to the pipeline between the outlet end of the medium supply device and the pipe inlet.

[0096] Wherein, the medium with a temperature of 80° is injected into the medium pipeline through the medium supply device to preheat the mold;

[0097] When the oil medium in the mold oil circuit reaches the set working temperature, the medium in the medium pipeline is heated to 120° C. by using the booster device to boost the pressure of the medium closed circulation pipeline, and the medium circulation of the medium closed circulation pipeline is opened;

[0098] When the upper and lower dies begin to close the mold and extrude the metal billet, the pressure relief device is opened, the pipeline between the medium supply device and the inlet end and the pipeline outlet is closed, and the boosting device is turned off; at this time, the medium supply device delivers a medium with a temperature of 80°C to the medium pipeline.

[0099] The medium in this embodiment can be water or oil. For example, if the medium is water, the mold temperature is clearly already higher than the set operating temperature of 300°C. When 80°C water is introduced, it vaporizes upon contact with the mold in the medium pipeline and is discharged through a pressure relief device, specifically a pressure relief valve or an air relief valve, thereby removing heat from the mold. This also helps lower the temperature of the oil medium in the oil circuit, resulting in a faster mold cooling efficiency overall. The purpose of the booster device is to increase the water pressure, thereby raising its boiling point.

[0100] When the working temperature of the mold reaches a set threshold temperature, the temperature of the medium supplied by the medium supply device to the medium pipeline is reduced at a rate of 1°C / min until the temperature of the mold reaches the set working temperature.

[0101] In this embodiment, the oil circuit or medium pipeline is preferably arranged on the surface where the mold core of the upper mold or lower mold contacts the mold sleeve. By opening the oil circuit or medium pipeline on the surface where the mold sleeve contacts the mold core, a complete pipeline structure is formed in cooperation with the surface of the mold core. Of course, the oil circuit or medium pipeline can also be integrally formed with the mold core during the casting process.

[0102] The above embodiments are merely exemplary embodiments of the present application and are not intended to limit the scope of the present application. The scope of protection of the present application is defined by the claims. Those skilled in the art may make various modifications or equivalent substitutions to the present application within the essence and scope of protection of the present application, and such modifications or equivalent substitutions shall also be deemed to fall within the scope of protection of the present application.

Claims

1. A deep hole hot extrusion die temperature control method, characterized in that: The steps include: Step 100: An oil circuit is provided in both the upper and lower dies of the deep hole extrusion die, and the inlet and outlet ends of the oil circuit are connected to a mold temperature controller so that the oil circuits in the upper and lower dies can form a closed-loop oil circuit; Step 200: In the oil circulation state of the open oil circuit, the heated oil medium is injected into the oil circuits of the upper mold and the lower mold through the mold temperature controller to preheat the mold; Step 300: Continue heating the oil medium in the oil circuits of the upper mold and the lower mold by the mold temperature controller until the oil medium reaches a set working temperature, so that the oil medium circulates in the oil circuit; Step 400: After the upper mold and the lower mold reach the operating temperature through monitoring by the thermocouple sensor, the upper mold and the lower mold begin to close the mold to extrude the metal billet; Step 500: The real-time temperature of the mold is obtained by thermocouples installed in the upper mold and the lower mold. When the mold operating temperature reaches a set threshold temperature, the mold temperature controller begins to reduce the temperature of the oil medium in the oil circuit of the upper mold and the lower mold, and adjusts the circulation flow rate of the oil medium in the oil circuit to cool the upper and lower molds through the oil medium. Step 600: After the upper and lower molds have completed demolding and clamping to produce a set number of parts, the mold temperature controller lowers the temperature of the oil medium in the oil circuit to a set cooling temperature, so that the oil medium in the oil circuit exchanges heat with the upper and lower molds to cool the upper and lower molds. Different independently controlled closed-circuit oil circuits are divided according to the number of inner and outer layers of the lower mold and the shape of the mold cavity, including: An independent closed-circulation oil circuit is provided on the contact surface of the inner and outer layers of the lower die; An independent closed-circulation oil circuit is set in the part with the same inner diameter of the mold cavity; An independent closed circulation oil circuit is provided in the layer structure portion where the inner diameter of the mold cavity changes continuously; The mold further comprises a medium supply device, a pressure relief device, a pressurizing device, and a medium pipeline arranged in the mold, wherein the medium pipeline has a pipeline inlet and a pipeline outlet, the outlet end of the medium supply device is connected to the pipeline inlet, and the inlet end of the medium supply device is connected to the pipeline outlet, forming a medium closed circulation loop, the pressure relief device is connected to the pipeline between the inlet end of the medium supply device and the pipeline outlet through a three-way valve; the pressurizing device is connected to the pipeline between the outlet end of the medium supply device and the pipeline inlet; Wherein, the medium with a temperature of 80° is injected into the medium pipeline through the medium supply device to preheat the mold; When the oil medium in the mold oil circuit reaches the set working temperature, the medium in the medium pipeline is heated to 120° C. by using the booster device to boost the pressure of the medium closed circulation pipeline, and the medium circulation of the medium closed circulation pipeline is opened; When the upper and lower dies begin to close and the metal blank is extruded, the pressure relief device is opened, the pipeline between the medium supply device and the inlet end and the pipeline outlet is closed, and the pressurizing device is turned off; at this time, the medium supply device delivers a medium at a temperature of 80° C. into the medium pipeline; When the working temperature of the mold reaches a set threshold temperature, the temperature of the medium supplied by the medium supply device to the medium pipeline is reduced at a rate of 1°C / min until the temperature of the mold reaches the set working temperature.

2. A deep hole hot extrusion die temperature control method according to claim 1, characterized in that: With the oil circuit open, perform oil circuit operation inspection on the upper and lower dies. The specific method is as follows: The mold temperature controller adjusts the pressure of the oil medium in the oil circuit to 0.3Mpa, the temperature of the oil medium is room temperature, and the oil medium circulates in the oil circuit for ten minutes. Then the mold temperature controller adjusts the temperature of the oil medium in the oil circuit to the first target temperature, which is set to 80°C, and detects the pressure state of the oil medium in the oil circuit.

3. A deep hole hot extrusion die temperature control method according to claim 2, characterized in that: When the oil medium pressure in the oil circuit is stable, the oil medium is heated at 2°C / min until the oil medium reaches the set working temperature, which is 300°C.

4. A deep hole hot extrusion die temperature control method according to claim 3, characterized in that: The mold temperature controller controls the circulation flow rate of the oil circuit of the upper mold and the lower mold at 20L / min when the oil medium temperature is 300℃.

5. The deep hole hot extrusion die temperature control method according to claim 1, characterized in that: When the working temperature of the upper mold and lower mold reaches the threshold temperature, the mold temperature controller starts to reduce the temperature of the oil medium in the oil circuit. The specific method includes: The temperature rise state parameters of the upper die and the lower die under different initial temperatures of the metal blank and the working cycle time of the upper die and the lower die in a single mold closing are obtained by thermocouples; When the working temperature of the upper mold and the lower mold reaches the third target temperature, the mold temperature controller reduces the temperature of the oil medium injected into the oil circuit according to the temperature increase state parameter.

6. A deep hole hot extrusion die temperature control method according to claim 1, characterized in that: The threshold temperature reached by the working temperature of the upper and lower molds is set to 350℃, and the mold temperature controller reduces the temperature of the oil medium injected into the oil circuit to 120℃.

7. The deep hole hot extrusion die temperature control method according to claim 1, characterized in that: The oil passage apertures in the upper and lower dies and the oil medium circulation flow rate in the oil passages are determined based on the outer diameter, inner diameter, inner hole depth and total height of the product extruded from the metal billet.

8. A deep hole hot extrusion die temperature control method according to claim 7, characterized in that: The oil medium circulation flow rate of the upper mold oil circuit is 20L / min, and the oil medium circulation flow rate of the lower mold oil circuit is 40L / min.

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