An oil bath stamping apparatus and process

Abstract

This invention relates to the field of low-temperature coating thermoforming stamping technology, and provides an oil bath stamping equipment and process, including: a chassis; a frame body, the frame body being fixedly installed on the top of the chassis, the frame body having a cavity for containing stamping oil inside; and a stamping die, the stamping die being installed in the cavity of the frame body. By placing the stamping process in an oil bath environment, the fluid isolation and lubrication effects of the stamping oil are utilized to effectively protect the low-temperature coating on the sheet metal surface, avoiding melting, peeling, and oxidation of the coating during high-temperature stamping. The stamping oil isolates air, eliminating the generation of oxide scale at the source, resulting in clean parts surfaces after stamping, eliminating the need for shot blasting, simplifying the production process, and reducing costs. The stamping oil circulation temperature control system realizes the recycling and precise temperature control of the stamping oil, ensuring the stability and consistency of process parameters and improving product quality.

Description

Technical Field

[0001] This invention relates to the field of low-temperature coating thermoforming stamping technology, and in particular to an oil bath stamping equipment and process. Background Technology

[0002] In the automotive manufacturing industry, hot stamping technology using high-strength steel sheets is widely used to achieve lightweight vehicle bodies and improve crash safety. The basic process of hot stamping involves heating the steel sheet to its austenitizing temperature (typically above 700°C), then rapidly transferring it to a die for stamping and simultaneous in-die hardening, thereby obtaining high-strength parts with a martensitic structure. To improve the corrosion resistance of the parts, the surface of the steel sheets used for hot stamping is usually pre-plated with zinc-based or aluminum-silicon coatings. However, zinc-based coatings have a low melting point (approximately 420°C) and are prone to melting and oxidation during the austenitizing process above 700°C, and can adhere to the die, leading to coating failure, die contamination, and a decline in the surface quality of the parts.

[0003] In existing technologies, high-melting-point aluminum-silicon coated plates are usually used, but their cost is high; or uncoated plates are stamped and then shot blasted to remove surface oxide scale, but the shot blasting process increases equipment investment, energy consumption and labor costs, and is prone to causing parts to deform. Summary of the Invention

[0004] This invention provides an oil bath stamping equipment and process, aiming to solve the problems in the prior art, which usually uses high-melting-point aluminum-silicon coated plates, but the cost is high; or uses uncoated plates for stamping and then shot blasting to remove surface oxide scale, but the shot blasting process increases equipment investment, energy consumption and labor costs, and is prone to causing parts deformation.

[0005] This invention is implemented as follows: an oil bath stamping device and process, comprising: a chassis; a frame body, the frame body being fixedly installed at the top of the chassis, the frame body having an internal chamber for containing stamping oil; a stamping die, the stamping die being installed in the chamber of the frame body, the stamping die being used for hot stamping and forming of heated sheet metal for coating; a heating radiant tube, the heating radiant tube being disposed on the inner wall of the chamber of the frame body, for preheating the stamping oil in the chamber to a preset temperature and maintaining the oil temperature; and a stamping oil circulation temperature control system, the stamping oil circulation temperature control system being disposed at the bottom of the chamber of the frame body, for controlling the entry and exit of stamping oil from the chamber of the frame body.

[0006] Preferably, the stamping die includes an upper die assembly and a lower die assembly, the upper die assembly and the lower die assembly are opposite to each other, the bottom of the lower die assembly is fixedly installed at the bottom of the cavity of the frame body, and the interior of the lower die assembly is provided with a cooling channel.

[0007] The beneficial effect of adopting the above-mentioned further solution is that the upper die assembly is connected to the hydraulic cylinder piston rod of the external hydraulic stamping system, and can move up and down under hydraulic drive to complete the stamping action.

[0008] Preferably, there are two sets of heating radiant tubes, which are symmetrically installed at both ends inside the frame body.

[0009] The beneficial effects of adopting the above-mentioned further scheme are: it is used to preheat the stamping oil in the chamber to 250°C and maintain a constant temperature. The two sets are symmetrically arranged, the heating and preheating are more uniform, and the efficiency is improved.

[0010] Preferably, the stamping oil circulation temperature control system includes: an oil circulation pipeline, an oil pump, a filter, a heater, and a cooler. The oil circulation pipeline is connected to the chamber of the frame body through the oil inlet pipe and the oil outlet pipe. The stamping oil is a high-temperature resistant and rust-proof stamping oil with a flash point of not less than 250°C.

[0011] The beneficial effects of adopting the above-mentioned further solution are: high-temperature resistant and rust-preventive stamping oil, preheated to 250°C, is injected into the cavity through the oil inlet pipe, so that the stamping oil completely submerges the stamping die. After stamping is completed, the oil can be extracted through the oil outlet pipe, filtered, cooled, and then recycled.

[0012] An oil bath stamping process includes the following steps:

[0013] S1: Inject preheated stamping oil into the cavity to immerse the stamping die, and at the same time start the heating radiation tube to preheat the cavity to the first preset temperature, forming an oil bath environment and maintaining the oil temperature;

[0014] S2: Heat and keep warm the metal sheet with the low-temperature coating;

[0015] S3: The heated sheet metal is placed on the stamping die using an external clamping device, so that the high-temperature sheet metal is immersed in stamping oil;

[0016] S4: Start the external hydraulic stamping system to drive the upper die assembly downward to stamp and form, and at the same time, introduce cooling medium into the cooling channel to quench and cool the sheet material;

[0017] S5: After stamping, open the mold and remove the plated sheet.

[0018] Preferably, the first preset temperature is 150℃~350℃, and the oil bath temperature is maintained within this range during the stamping process.

[0019] The beneficial effect of adopting the above-mentioned further solution is that, by stamping in an oil bath environment, the stamping oil forms a fluid isolation layer between the high-temperature sheet and the mold.

[0020] Preferably, the sheet material needs to be heated to 700°C in step S2.

[0021] Preferably, the low-temperature coating in step S2 is a zinc-based coating or a zinc alloy coating.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows: The oil bath stamping equipment and process of the present invention, by placing the stamping process in an oil bath environment, utilizes the fluid isolation and lubrication effect of the stamping oil to effectively protect the low-temperature coating on the surface of the sheet metal, avoiding melting, peeling and oxidation of the coating during the high-temperature stamping process; the stamping oil isolates the air, eliminating the generation of oxide scale at the source, resulting in clean parts surfaces after stamping, eliminating the need for shot blasting, simplifying the production process and reducing costs; the stamping oil circulation temperature control system realizes the recycling and precise temperature control of the stamping oil, ensuring the stability and consistency of process parameters and improving product quality. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of the present invention;

[0024] Figure 2 for Figure 1 A schematic diagram of the side view structure;

[0025] Figure 3 for Figure 1 Another side view of the structure.

[0026] In the diagram: 1. Chassis; 2. Frame body; 3. Stamping die; 31. Upper die assembly; 32. Lower die assembly; 33. Cooling channel; 4. Heating radiant tube; 5. Stamping oil circulation temperature control system; 51. Oil inlet pipe; 52. Oil outlet pipe. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0028] Please see Figure 1-3 This invention provides an oil bath stamping equipment and process technology solution: an oil bath stamping equipment and process, comprising:

[0029] Chassis 1;

[0030] The frame body 2 is fixedly installed on the top of the chassis 1, and the frame body 2 has a chamber for containing stamping oil inside.

[0031] The stamping die 3 is installed in the cavity of the frame body 2. The stamping die 3 is used to perform coating stamping thermoforming on the heated sheet metal.

[0032] Heating radiation tube 4 is installed on the inner wall of the cavity of the frame body 2 to preheat the stamping oil in the cavity to a preset temperature and maintain the oil temperature.

[0033] The stamping oil circulation temperature control system 5 is located at the bottom of the chamber of the frame body 2 and is used to control the stamping oil entering and exiting the chamber of the frame body 2.

[0034] In this embodiment, the chassis 1 is an integral welded steel frame structure used to support and install the various components of the equipment. The frame body 2 is fixedly installed on the top of the chassis 1 and is welded from high-temperature resistant stainless steel plates, forming a sealed chamber inside to contain the stamping oil.

[0035] Furthermore, the stamping die 3 includes an upper die assembly 31 and a lower die assembly 32, which are positioned opposite each other. The bottom of the lower die assembly 32 is fixedly installed at the bottom of the cavity of the frame body 2, and a cooling channel 33 is provided inside the lower die assembly 32.

[0036] In this embodiment, the stamping die 3 is installed in the cavity of the frame body 2, and includes an upper die assembly 31 and a lower die assembly 32 arranged opposite to each other. The bottom of the lower die assembly 32 is fixedly installed at the bottom of the cavity, and a conformal cooling channel 33 is provided inside it for quenching the sheet metal by introducing coolant during stamping. The upper die assembly 31 is connected to the piston rod of the hydraulic cylinder of the external hydraulic stamping system, and can move up and down under hydraulic drive to complete the stamping action.

[0037] Typically, there are two sets of heating radiation tubes 4, which are symmetrically installed at both ends inside the frame body 2.

[0038] In this embodiment, two sets of heating radiant tubes 4 are provided, symmetrically installed on the inner walls at both ends of the frame body 2. The heating radiant tubes 4 are electrically heated quartz tubes with adjustable power, used to preheat the stamping oil in the chamber to 250°C and maintain a constant temperature.

[0039] Specifically, the stamping oil circulation temperature control system 5 includes: oil circulation pipeline, oil pump, filter, heater and cooler. The oil circulation pipeline is connected to the chamber of the frame body 2 through the oil inlet pipe 51 and the oil outlet pipe 52.

[0040] In addition, the stamping oil is a high-temperature resistant and rust-preventive stamping oil with a flash point of not less than 250°C.

[0041] In this embodiment, the stamping oil circulation temperature control system 5 is located at the bottom of the chamber of the frame body 2, and includes an oil circulation pipeline, an oil pump, a filter, a heater, and a cooler. The oil circulation pipeline is connected to the chamber through an oil inlet pipe 51 and an oil outlet pipe 52. Before stamping, high-temperature resistant and rust-preventive stamping oil preheated to 250°C is injected into the chamber through the oil inlet pipe 51, so that the stamping oil completely submerges the stamping die 3. After stamping, the oil can be extracted through the oil outlet pipe 52, filtered, cooled, and then recycled.

[0042] An oil bath stamping process includes the following steps:

[0043] S1: Preheated stamping oil is injected into the cavity to immerse the stamping die 3. Simultaneously, the heating radiant tube 4 is activated to preheat the cavity to a first preset temperature, forming an oil bath environment and maintaining the oil temperature. High-temperature resistant and rust-proof stamping oil, preheated to 250°C, is injected into the cavity through the oil inlet pipe 51, filling the entire cavity and immersing the internal stamping die 3. Continuous heating is provided through the heating radiant tube 4, and combined with feedback control from an external temperature sensor, the oil bath temperature is maintained at 250°C ± 10°C.

[0044] S2: Heat and keep warm the metal sheet with the low-temperature coating;

[0045] S2: The heated sheet metal is placed on the stamping die 3 by an external clamping device, so that the high-temperature sheet metal is immersed in stamping oil;

[0046] S3: Start the external hydraulic stamping system to drive the upper die assembly 31 downward to perform stamping and forming, and at the same time, introduce cooling medium into the cooling channel 33 to quench and cool the sheet material.

[0047] S4: After stamping, the mold is opened and the plated sheet is removed. The external hydraulic stamping system drives the upper mold assembly 31 to return. The external clamping equipment removes the formed part from the chamber and sends it to the next station. After stamping is completed, the oil outlet pipe 52 is opened and the oil pump is started to recover some of the used stamping oil to the circulating temperature control system 5. After impurities are removed by the filter, the oil temperature is reduced to 250°C by the cooler and then injected back into the chamber, realizing the recycling of stamping oil.

[0048] In addition, the first preset temperature in step S1 is 150℃~350℃, and the oil bath temperature is maintained within this range during the stamping process.

[0049] Furthermore, in step S2, the sheet material needs to be heated to 700°C.

[0050] It should be noted that the low-temperature coating in step S2 is a zinc-based coating or a zinc alloy coating.

[0051] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An oil bath stamping device, characterized in that, include: Chassis (1); The frame body (2) is fixedly installed on the top of the chassis (1), and the frame body (2) has a chamber for containing stamping oil inside; A stamping die (3) is installed in the cavity of the frame body (2). The stamping die (3) is used to perform plating stamping thermoforming on the heated sheet metal. Heating radiation tube (4), the heating radiation tube (4) is disposed on the inner wall of the cavity of the frame body (2) for preheating the stamping oil in the cavity to a preset temperature and maintaining the oil temperature; The stamping oil circulation temperature control system (5) is located at the bottom of the chamber of the frame body (2) and is used to control the stamping oil to enter and exit the chamber of the frame body (2).

2. The oil bath stamping equipment according to claim 1, characterized in that: The stamping die (3) includes an upper die assembly (31) and a lower die assembly (32). The upper die assembly (31) and the lower die assembly (32) are opposite to each other. The bottom of the lower die assembly (32) is fixedly installed at the bottom of the cavity of the frame body (2). The interior of the lower die assembly (32) is provided with a cooling channel (33).

3. The oil bath stamping equipment according to claim 1, characterized in that: The heating radiation tubes (4) are provided in two sets, and the two sets of heating radiation tubes (4) are symmetrically installed at both ends inside the frame body (2).

4. The oil bath stamping equipment according to claim 1, characterized in that: The stamping oil circulation temperature control system (5) includes: oil circulation pipeline, oil pump, filter, heater and cooler. The oil circulation pipeline is connected to the chamber of the frame body (2) through the oil inlet pipe (51) and the oil outlet pipe (52).

5. The oil bath stamping equipment according to claim 1, characterized in that: The stamping oil is a high-temperature resistant and rust-preventive stamping oil with a flash point of not less than 250°C.

6. An oil bath stamping process, employing the oil bath stamping equipment as described in any one of claims 1 to 5, characterized in that, Includes the following steps: S1: Inject preheated stamping oil into the cavity to immerse the stamping die (3), and at the same time start the heating radiation tube (4) to preheat the cavity to the first preset temperature, forming an oil bath environment and maintaining the oil temperature; S2: Heat and keep warm the metal sheet with the low-temperature coating; S2: The heated sheet metal is placed on the stamping die (3) by an external clamping device, so that the high-temperature sheet metal is immersed in the stamping oil; S3: Start the external hydraulic stamping system to drive the upper die assembly (31) downward to perform stamping and forming, and at the same time, introduce cooling medium into the cooling channel (33) to quench and cool the sheet material; S4: After stamping, open the mold and remove the plated sheet.

7. The oil bath stamping process according to claim 6, characterized in that: In step S1, the first preset temperature is 150℃~350℃, and the oil bath temperature is maintained within this range during the stamping process.

8. The oil bath stamping process according to claim 1, characterized in that: In step S2, the sheet material needs to be heated to 700°C.

9. The oil bath stamping process according to claim 1, characterized in that: In step S2, the low-temperature coating is a zinc-based coating or a zinc alloy coating.

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