Temperature control method for deep hole hot extrusion die

Abstract

The invention discloses a deep hole hot extrusion die temperature control method which comprises the following steps: injecting a heated oil medium into an oil path of an upper die and a lower die through a die temperature controller, and preheating; after the mold temperature controller continues to heat the oil medium to the set temperature, the oil medium circulates in the oil way; after the working temperatures of the upper die and the lower die are monitored and obtained through a thermocouple sensor, the upper die and the lower die are closed; when the working temperature reaches the set temperature, the mold temperature controller reduces the temperature of an oil medium in an oil way of the upper mold and the lower mold, and the circulating flow of the oil medium in the oil way is adjusted; after production is completed, the temperature of the oil medium in the oil way is reduced through the mold temperature controller, and the upper mold and the lower mold are cooled. The temperature and flow of the oil medium are adjusted through the mold temperature controller, the mold temperature is adjusted through heat transfer of the oil medium, the mold temperature is monitored by the thermocouple sensor in real time, the thermocouple feeds monitoring data back to the mold temperature controller, the whole process forms a closed loop with the temperature accurately adjusted and controlled, and it is guaranteed that the mold is located in the most appropriate working temperature interval all the time.

Description

Technical Field

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

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

[0003] During the extrusion production process of deep hole hot extrusion dies, the temperature of the die rises due to heat conduction between the billet and the die, and the die needs to be cooled down. If the die temperature cannot be reduced in time, the die annealing will fail, resulting in unqualified products and die scrapping. In the extrusion process of large-volume metal billets, the billet and the die are usually in contact and heat transfer. Since the contact time, contact area, and deformation degree of each part of the billet and the die are changing, there will be temperature differences in each part of the die, and the temperature needs to be regulated in time.

[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 method.

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

[0007] A deep hole hot extrusion die temperature control method comprises the following steps:

[0008] Step 100, an oil circuit is provided in both the upper die and the lower die 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 die and the lower die can form a closed-loop oil circuit;

[0009] Step 200: In the oil circulation state of opening the oil circuit, inject the heated oil medium 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 to heat 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 die and the lower die reach the working temperature through monitoring by the thermocouple sensor, the upper die and the lower die begin to close the die to extrude the metal blank;

[0012] Step 500, the real-time temperature of the mold is obtained by thermocouples arranged in the upper mold and the lower mold, and when the working temperature of the mold reaches the set threshold temperature, the mold temperature controller starts 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 of the oil medium in the oil circuit, so as to cool the upper and lower molds through the oil medium;

[0013] Step 600: After the upper mold and the lower mold have completed demolding and closing the set number of parts to be produced, 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 mold and the lower mold to cool the upper mold and the lower mold.

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

[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 20L / min when the oil medium temperature is 300°C.

[0018] As a preferred solution 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 temperatures of the upper mold and the lower mold reach 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 path diameters in the upper and lower dies and the oil medium circulation flow rate of the oil path 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 embodiment 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 between the inner and outer layer structures of the lower die;

[0026] An independent closed circulation oil circuit is provided 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 solution of the present invention, it also includes a medium supply device, a pressure relief device, a pressurizing device and a medium pipeline arranged in the mold, 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 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 a 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 die and the lower die begin to close the die and the metal blank is extruded and formed, 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 booster device is closed; at this time, the medium supply device delivers a medium with a temperature of 80° C. to the medium pipeline;

[0032] When the working temperature of the mold reaches a set threshold temperature, the temperature 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 the high temperature resistant oil is heated and cooled in different stages by 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, it is determined whether the mold is overheated, and the mold temperature is lowered by heat conduction between the oil medium and the mold, thereby ensuring that the mold is always in the most suitable working temperature range. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0036] Figure 1 A schematic diagram of a control method flow chart of 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 This is a schematic diagram of the distribution of the medium pipeline, pipeline inlet, and pipeline outlet in the upper mold of 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-lower die oil circuit oil outlet; 2-lower die oil circuit oil inlet; 3-upper die oil circuit oil outlet; 4-upper die oil circuit oil inlet; 5-medium pipeline; 6-medium supply device; 7-boosting device; 8-pressure relief device; 9-three-way valve; 10-oil circuit; 11-upper die seat; 12-lower die; 13-upper die; 14-middle fixing part. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 creative work 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 best working temperature of metal hot extrusion die is about 300℃, so the die needs to be preheated before production starts to avoid die sticking or large temperature drop due to large temperature difference between the die 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-volume deep-hole parts have various shapes and different material properties. During the extrusion process, the blank contacts the die for heat transfer. Since the contact time, contact area, and deformation degree of each part of the blank and the die are changing, there will be temperature differences in each part of the die, and the temperature needs to be regulated in time.

[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 die and the lower die 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 die and the lower die can form a closed-loop oil circuit;

[0048] Step 200: In the oil circulation state of opening the oil circuit, inject the heated oil medium 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 to heat 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 die and the lower die reach the working temperature through monitoring by the thermocouple sensor, the upper die and the lower die begin to close the die to extrude the metal blank;

[0051] Step 500, the real-time temperature of the mold is obtained by thermocouples arranged in the upper mold and the lower mold, and when the working temperature of the mold reaches the set threshold temperature, the mold temperature controller starts 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 of the oil medium in the oil circuit, so as to cool the upper and lower molds through the oil medium;

[0052] Step 600: After the upper mold and the lower mold have completed demolding and closing the set number of parts to be produced, 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 mold and the lower mold to cool the upper mold and the lower mold.

[0053] In this embodiment, an oil circuit capable of forming a closed oil medium circulation is provided in the upper and lower dies of the deep hole hot extrusion die. The circulation of the medium in the oil circuit is realized by connecting the oil inlet and outlet of the oil circuit to the mold temperature controller, thereby realizing the temperature control of the upper and lower dies of the die. 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, which can greatly improve the quality of forgings and die life and reduce production costs.

[0054] In the oil circuit of the present 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 the structural strength of the mold design, 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 dispersed in the oil circuit, and the temperature is adjusted after being fed back to the mold temperature controller. 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 oil temperature is lowered by the mold temperature controller, and the mold temperature is lowered by heat conduction between the oil and the mold to ensure that the mold is always in the most suitable working 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 processed in a targeted manner according to the inner surface characteristics of large deep-hole parts and the material temperature characteristics, so that the upper die temperature is controlled within a reasonable range.

[0059] For example, the head of a certain type of large hot extrusion part deforms violently, the temperature rises rapidly, a large amount of heat is concentrated, and heat is transferred to the upper die in a short time. It is necessary to increase the diameter of the oil line at the upper die head, increase the oil line spiral pitch, control the temperature with a short-term mold temperature controller, increase the flow rate, and quickly reduce the temperature of the upper die.

[0060] The lower die of a large hot extrusion die is huge, the strength margin is sufficient when the die is designed, the inner and outer layers of the die are tightly nested, and the oil circuit setting is more flexible and effective. When the part is formed, the outer surface has a large contact area with the inner wall of the lower die, the heat transfer is fast, and the cross-sectional area and layout of the oil circuit are appropriately adjusted. In addition to the spiral line, the oil circuit can also be arranged in the form of a "return" or a spiral winding tube, and different layouts can be used in combination. The method of zoning and segmented temperature control is adopted to connect the mold temperature machine, temperature sensor and the oil circuits of different layouts in each area of ​​the lower die in parallel to accurately control the temperature of the lower die.

[0061] For example, a certain type of large hot extrusion part has a small head and severe deformation. The temperature rises quickly during forming, but it is large and long, and the temperature drops slowly after forming. The inner surface of the bottom of the lower die contacts the outer surface of the part head, and a large cross-sectional area is used to increase the density of the oil circuit arrangement, and the oil circuit is in the form of a "U" or spiral winding tube. The tail of the part cools down quickly, and the cooling rate needs to be reduced to keep it consistent with the head of the part. The area where the lower die contacts the tail of the part uses a spiral oil circuit to slowly control the cooling.

[0062] like Figure 3 , Figure 4 As shown, in this embodiment, the upper die and the lower die suitable for extrusion forming of large metal parts are in the form of two inner and outer layers nested with 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 difficulty of processing.

[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] According to the shape and material characteristics of the processed parts at different temperatures, different oil circuits are designed in different areas of the mold to achieve differentiated mold temperature control. While ensuring the hot extrusion yield, it reduces the disadvantage of the mold's service life being reduced by drastic temperature changes caused by heat conduction.

[0065] Specifically, in the state of opening the oil circuit circulation, the oil circuit operation detection of the upper mold and the lower mold is carried out. 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 to be 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 specific method for the mold temperature controller to start lowering the temperature of the oil medium in the oil circuit includes:

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

[0071] When the working temperatures of the upper mold and the lower mold reach 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 realize real-time monitoring of the mold temperature 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 die and the lower die and the oil medium circulation flow rate of the oil passage are determined according to the outer diameter, inner diameter, inner hole depth and total height of the product formed by extrusion of the metal billet, which is specifically described by the following embodiments:

[0076] Step 1: First, connect the mold temperature controller to the oil circuits of the upper mold and the lower mold, and adjust the oil outlet pressure to 0.3MPa. Let the oil circulate in the oil circuit for 10 minutes to test the operation of the mold temperature controller and the oil leakage of 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, the mold temperature controller will increase the temperature at 2°C / min until the oil temperature reaches 300°C.

[0078] Step 3: Open the control valve of the oil circuit circulation, 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 piece of metal billet, the die temperature reaches 437°C, the oil temperature of the oil inlet of the oil circuit is reduced to 120°C, and the temperature of the upper die and the lower die is reduced to 350°C within 2 minutes, which is in 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 kept at 120°C, which can ensure that the mold temperature is always at 300-350°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 of 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] 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. 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 two-layer structure, specifically including:

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

[0086] A closed circulation oil circuit is arranged in the layer structure part 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 make 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 circuit circulation is set in the upper mold base 13. Instead, an intermediate fixing member 14 is set in the middle of the upper mold, and an oil circuit is set in the intermediate fixing member 14 or in the intermediate fixing member 14 and the upper mold 13.

[0090] In this embodiment, different 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 vary according to the different shapes of the metal billets and the different temperature control requirements of different parts.

[0092] According to the shape and material properties 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 uneven temperature distribution in the mold in a short period of time, and the quality of the mold extrusion 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] A medium supply device, a pressure relief device, a booster device and a 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 circuit 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 to form 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 booster 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 a 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 transports 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 temperature of the mold is obviously higher than the set working temperature of 300°C. If 80°C water is introduced, the water will vaporize after contacting the mold in the medium pipeline and be discharged from the pressure relief device, which can be a pressure relief valve or an air relief valve, thereby taking away the heat of the mold. At the same time, it can also assist in reducing the temperature of the oil medium in the oil circuit. On the whole, the mold can achieve faster cooling efficiency in a short time. The purpose of setting up a booster device is to increase the pressure of the water, thereby increasing the boiling point of the water.

[0100] When the working temperature of the mold reaches a set threshold temperature, the temperature 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 the 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 only exemplary embodiments of the present application and are not intended to limit the present application. The protection scope 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 protection scope of the present application, and such modifications or equivalent substitutions shall also be deemed to fall within the protection scope 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 die and the lower die 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 die and the lower die can form a closed-loop oil circuit; Step 200: In the oil circulation state of opening the oil circuit, inject the heated oil medium into the oil circuits of the upper mold and the lower mold through the mold temperature controller to preheat the mold; Step 300, continue to heat 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 die and the lower die reach the working temperature through monitoring by the thermocouple sensor, the upper die and the lower die begin to close the die to extrude the metal blank; Step 500, the real-time temperature of the mold is obtained by thermocouples arranged in the upper mold and the lower mold, and when the working temperature of the mold reaches the set threshold temperature, the mold temperature controller starts 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 of the oil medium in the oil circuit, so as to cool the upper and lower molds through the oil medium; Step 600: After the upper mold and the lower mold have completed demolding and closing the set number of parts to be produced, 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 mold and the lower mold to cool the upper mold and the lower mold.

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, and the set working temperature of the oil medium is 300°C.

4. A deep hole hot extrusion die temperature control method according to claim 1, characterized in that: The mold temperature controller controls the circulation flow rate of the oil circuit of the upper mold and the lower mold to be 20L / min when the oil medium temperature is 300℃.

5. A deep hole hot extrusion die temperature control method according to claim 1, characterized in that: 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: 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 temperatures of the upper mold and the lower mold reach 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°C, and the mold temperature controller reduces the temperature of the oil medium injected into the oil circuit to 120°C.

7. A 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 of the oil passages are determined according to the outer diameter, inner diameter, inner hole depth and total height of the product formed by extrusion of 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 oil circuit of the upper mold is 20L / min, and the oil medium circulation flow rate of the oil circuit of the lower mold is 40L / min.

9. A deep hole hot extrusion die temperature control method according to claim 1, characterized in that: 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, including: An independent closed-circulation oil circuit is provided on the contact surface between the inner and outer layer structures of the lower die; An independent closed circulation oil circuit is provided 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.

10. A deep hole hot extrusion die temperature control method according to claim 9, characterized in that: It also includes a medium supply device, a pressure relief device, a pressurizing device, and a medium pipeline arranged in the mold, 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 pressurizing device is connected to the pipeline between the outlet end of the medium supply device and the pipe 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 a 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 die and the lower die begin to close the die and the metal blank is extruded and formed, 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 booster device is closed; at this time, the medium supply device delivers a medium with a temperature of 80° C. to the medium pipeline; When the working temperature of the mold reaches a set threshold temperature, the temperature 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.

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