QPQ treated workpiece rapid cooling device

Abstract

The utility model relates to workpiece cooling technical field, specifically disclose a kind of workpiece rapid cooling device after QPQ processing, including cooling box, the inner wall of cooling box is provided with liquid level sensor, the top of cooling box is hinged with sealing cover, lifting mechanism for lifting workpiece is provided on the cooling box;The lifting mechanism includes two symmetrical distribution's recesses of being opened in the top of cooling box, the recess inside bottom end surface is provided with mounting groove, the inside of mounting groove is equipped with first electric push rod, the output end of first electric push rod is fixedly installed with fixed plate, to ensure that workpiece is completely isolated from oxygen in the whole cooling process, solve the surface oxidation problem of high-temperature workpiece in cooling process, maintain the surface quality and high corrosion resistance after QPQ processing, and realize efficient, uniform heat exchange, compared with natural air cooling, cooling efficiency is improved more than several times, production cycle is significantly shortened.

Description

Technical Field

[0001] This utility model relates to the field of workpiece cooling technology, and specifically discloses a rapid cooling device for workpieces after QPQ treatment. Background Technology

[0002] QPQ (Quench-Polish-Quench) treatment is a widely used surface strengthening technology for metal workpieces, significantly improving their wear resistance, corrosion resistance, and fatigue strength. The process mainly comprises three core steps: salt bath nitriding, salt bath oxidation, and cooling. After undergoing nitriding and oxidation salt bath treatments at 500-600℃, the workpiece must be cooled to fix the modified surface layer, thereby achieving the desired properties.

[0003] Currently, the main methods for cooling workpieces after QPQ processing are as follows:

[0004] (1) Natural air cooling involves directly exposing the workpiece to the air for natural cooling. Not only is the cooling rate extremely slow, severely restricting production pace and resulting in low efficiency, but also, when workpieces at high temperatures (usually above 400℃) are cooled in the air, their surfaces react violently with oxygen in the air, forming a loose oxide layer. This oxide layer not only affects the product's appearance but also damages the dense, highly corrosion-resistant compound layer formed by QPQ treatment, leading to a significant decrease in product performance.

[0005] (2) Direct water cooling: In order to improve the cooling rate, some operators will immerse the workpiece directly in water for rapid cooling. Although this method improves the cooling rate, the huge temperature difference between the high-temperature workpiece (about 400°C) and the room-temperature cooling water (about 25°C) will cause severe thermal shock. This instantaneous and uneven cooling will generate huge structural stress inside the workpiece. For thin-walled parts, complex structures, or materials with poor hardenability, it is very easy to cause the workpiece to warp, deform, or even crack, resulting in product scrap. Utility Model Content

[0006] This invention proposes a rapid cooling device for workpieces after QPQ treatment, which ensures that the workpiece is completely isolated from oxygen throughout the cooling process, solves the problem of surface oxidation of high-temperature workpieces during the cooling process, maintains the surface quality and high corrosion resistance of QPQ treated workpieces, and achieves efficient and uniform heat exchange. Compared with natural air cooling, the cooling efficiency is increased by several times, significantly shortening the production cycle.

[0007] This utility model is implemented as follows: a rapid cooling device for workpieces after QPQ treatment includes a cooling box, a liquid level sensor is provided on the inner wall of the cooling box, a sealing cover is hinged to the top of the cooling box, and a lifting mechanism for lifting the workpiece is provided on the cooling box.

[0008] The lifting mechanism comprises two symmetrically distributed grooves formed at the top of the cooling box, the bottom end surface inside each groove is provided with a mounting groove, a first electric push rod is installed inside the mounting groove, the output end of the first electric push rod is fixedly provided with a fixing plate, and a mesh basket located inside the cooling box is fixedly installed between the two fixing plates;

[0009] A water spray pipe in a "loop" shape is fixedly installed on the inner side wall of the cooling box, and the water spray pipe is located below the liquid level sensor and communicated with a plurality of water outlets on one side close to the mesh basket;

[0010] An air inlet pipe penetrates through and is fixedly installed at the right end of the top of the sealing cover, the outer side wall of the air inlet pipe is sequentially provided with a solenoid valve and a flow meter along the air flow direction, and one end of the air inlet pipe extends into the interior of the mesh basket.

[0011] As a preference of the device for rapidly cooling workpieces after QPQ treatment of the utility model, the top of the sealing cover is provided with a pressure relief valve and a temperature sensor with a probe extending into the interior of the cooling box, the left end of the top of the sealing cover penetrates through and is fixedly connected with an exhaust pipe, and the outer side wall of the exhaust pipe is sequentially provided with an online oxygen content analyzer and a solenoid valve along the gas flow direction.

[0012] As a preference of the device for rapidly cooling workpieces after QPQ treatment of the utility model, a sealing strip in a "loop" shape is fixedly installed on the inner side wall of the sealing cover, and the top of the cooling box is provided with a sealing groove matched with the sealing strip.

[0013] As a preference of the device for rapidly cooling workpieces after QPQ treatment of the utility model, the outer side wall of the cooling box is provided with a water chiller and a water pump, a water outlet pipe is communicated between the cooling box and the water inlet end of the water chiller, the outer side wall of the water spray pipe is communicated with a water supply pipe extending to the outside of the cooling box, and the water outlet end and the water inlet end of the water pump are respectively connected with the water supply pipe and the water outlet end of the water chiller.

[0014] As a preference of the device for rapidly cooling workpieces after QPQ treatment of the utility model, the bottom end surface inside the cooling box is arranged in an inclined manner, the outer side wall of the cooling box is communicated with a drain pipe, and a manual valve is arranged on the drain pipe.

[0015] As a preference of the device for rapidly cooling workpieces after QPQ treatment of the utility model, a thermal insulation interlayer is arranged between the outer side wall and the inner side wall of the cooling box, and the interior of the thermal insulation interlayer is filled with a thermal insulation material.

[0016] As a preferred embodiment of the rapid cooling device for workpieces after QPQ treatment according to this utility model, the left and right side walls of the cooling box and the left and right side walls of the sealing cover are all fixedly installed with support plates, and a second electric push rod for driving the opening and closing of the sealing cover is hinged between the two support plates on the same side.

[0017] The beneficial effects of this utility model are:

[0018] 1. By using a sealed cover and the combination of an inlet pipe and an exhaust pipe, the air in the cooling chamber is quickly and completely replaced with inert gases such as nitrogen, creating an oxygen-free environment. By installing an online oxygen content analyzer on the exhaust pipe, the replacement endpoint can be accurately and reliably determined, ensuring that the workpiece is completely isolated from oxygen throughout the cooling process. This solves the problem of surface oxidation of high-temperature workpieces during the cooling process and maintains the surface quality and high corrosion resistance of QPQ treated workpieces.

[0019] 2. By adopting an active forced refrigeration cycle consisting of a chiller, water pump and spray pipe, a low-temperature cooling medium can be continuously provided. Through multiple outlets on the "U"-shaped spray pipe, the workpiece is evenly and gently washed from all sides, achieving efficient and uniform heat exchange. Compared with natural air cooling, the cooling efficiency is increased by several times, significantly shortening the production cycle. Attached Figure Description

[0020] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0021] Figure 1 This is a front sectional view of a rapid cooling device for workpieces after QPQ treatment according to this utility model.

[0022] Figure 2 This is an overall structural diagram of the present invention.

[0023] Figure 3 This is a top view of the cooling box of this utility model;

[0024] Figure 4 This is a structural diagram of the basket of this utility model.

[0025] The markings in the diagram are as follows: 1. Cooling box; 101. Drain pipe; 102. Insulation layer; 103. Water outlet pipe; 104. Chiller; 2. Sealing cover; 201. Sealing strip; 202. Sealing groove; 3. Groove; 301. Mounting groove; 4. First electric actuator; 401. Fixing plate; 402. Wire basket; 5. Water spray pipe; 501. Water inlet pipe; 502. Water pump; 6. Air inlet pipe; 601. Flow meter; 7. Pressure relief valve; 701. Temperature sensor; 8. Exhaust pipe; 801. Online oxygen content analyzer; 9. Second electric actuator. Detailed Implementation

[0026] The present invention will be further described below with reference to the accompanying drawings and specific embodiments to aid in understanding its content. Unless otherwise specified, the methods used in this invention are conventional methods; the raw materials and apparatus used, unless otherwise specified, are conventional commercially available products.

[0027] Please see Figure 1-4 A rapid cooling device for workpieces after QPQ treatment includes a cooling box 1, a liquid level sensor is provided on the inner wall of the cooling box 1, a sealing cover 2 is hinged to the top of the cooling box 1, and a lifting mechanism for lifting the workpiece is provided on the cooling box 1.

[0028] The lifting mechanism includes two symmetrically distributed grooves 3 on the top of the cooling box 1. The bottom surface of the groove 3 is provided with a mounting groove 301. A first electric push rod 4 is installed inside the mounting groove 301. A fixing plate 401 is fixedly installed at the output end of the first electric push rod 4. A wire basket 402 located inside the cooling box 1 is fixedly installed between the two fixing plates 401.

[0029] A water spray pipe 5 in the shape of a "U" is fixedly installed on the inner wall of the cooling box 1. The water spray pipe 5 is located below the liquid level sensor and has multiple water outlets connected to the side near the mesh basket 402.

[0030] An air inlet pipe 6 is installed through and fixedly mounted on the right end of the top of the sealing cover 2. A solenoid valve and a flow meter 601 are arranged sequentially on the outer wall of the air inlet pipe 6 along the airflow direction. One end of the air inlet pipe 6 extends into the interior of the basket 402.

[0031] In this embodiment: The operator quickly places the workpiece, which has undergone QPQ oxidation salt bath treatment and is at a high temperature of approximately 400°C, into the mesh basket 402, closes the sealing cover 2, and introduces high-purity nitrogen gas into the sealed cooling chamber 1 through the air inlet pipe 6. The flow meter 601 monitors and measures the total amount of nitrogen gas introduced in real time. The density of the introduced nitrogen gas is different from that of air, which will form an airflow, expelling the original air in the cooling chamber 1 through the exhaust pipe 8 located on the other side. The online oxygen content analyzer 801 installed on the exhaust pipe 8 continuously monitors the oxygen concentration of the exhaust gas. When the oxygen concentration is stably lower than the preset safety threshold, it is confirmed that an oxygen-free environment has been successfully established in the cooling chamber 1. After confirming an oxygen-free environment, the first electric actuator 4 is activated, driving the basket 402 and the workpiece inside, which is in a high-temperature state, to be smoothly immersed in the pre-prepared low-temperature cooling medium. The water pump 502 is started, and the cooling medium in the cooling tank 1, which has been heated by the workpiece, flows into the chiller 104 through the water outlet pipe 103, causing its temperature to drop back to the set low temperature. The cooled medium is then pressurized by the water pump 502 through the outlet of the chiller 104 and delivered to the "U"-shaped spray pipe 5 through the water inlet pipe 501. Finally, it is sprayed out from many outlets at a certain pressure, evenly and gently washing each workpiece in the basket 402 from all sides, thus ensuring that the workpiece is completely isolated from oxygen throughout the cooling process. This solves the problem of surface oxidation of high-temperature workpieces during the cooling process, maintains the surface quality and high corrosion resistance after QPQ treatment, and achieves efficient and uniform heat exchange. Compared with natural air cooling, the cooling efficiency is increased by several times, significantly shortening the production cycle.

[0032] Once the temperature sensor 701 detects that the workpiece temperature has cooled to the process requirement, the basket 402 is lifted, and finally the sealing cover 2 is opened to remove the workpiece.

[0033] It should be noted that the water spray pipe 5 is "U" shaped, that is, it is set around the mesh basket 402 to ensure that the cooling medium is sprayed evenly.

[0034] As a technical optimization of this utility model, the top of the sealing cover 2 is provided with a pressure relief valve 7 and a temperature sensor 701 whose probe extends into the interior of the cooling box 1. The left end of the top of the sealing cover 2 is connected to an exhaust pipe 8. The outer wall of the exhaust pipe 8 is provided with an online oxygen content analyzer 801 and a solenoid valve in sequence along the direction of gas flow.

[0035] In this embodiment: the pressure relief valve 7 is a mechanical safety device with a preset pressure spring inside. When nitrogen is introduced into the cooling box 1, the pressure inside the cooling box 1 exceeds the safety set value, and the gas pressure will overcome the spring force to push open the valve for pressure relief. The probe of the temperature sensor 701 is directly immersed in the medium inside the cooling box 1 to monitor the temperature of the cooling medium in real time, ensuring that it is within the low temperature range required by the process. For the exhaust pipe 8 and the online oxygen content analyzer 801, during the process of introducing nitrogen to displace air, the solenoid valve opens, and the original air and part of the mixed gas in the cooling box 1 are discharged through the exhaust pipe 8. The online oxygen content analyzer 801 monitors the oxygen concentration in the discharged gas in real time, which can determine whether the air has been completely displaced. When the online oxygen content analyzer 801 shows that the oxygen concentration of the discharged gas is stable at an extremely low preset value, it proves that the air in the cooling box 1 has been successfully displaced by high-purity nitrogen, forming a qualified oxygen-free environment. At this time, gas introduction can be stopped or the system can be switched to a pressure maintaining state, so as to ensure that the workpiece will not be oxidized during the cooling process.

[0036] As a technical optimization solution of the utility model, a seal strip 201 in a "loop" shape is fixedly installed on the inner side wall of the sealing cover 2, and the top of the cooling box 1 is provided with a sealing groove 202 matching the seal strip 201.

[0037] In this embodiment: when the sealing cover 2 is closed, the "loop"-shaped seal strip 201 (usually made of high-temperature resistant and aging-resistant silicone rubber or fluororubber) is tightly pressed into the "loop"-shaped sealing groove 202. The rubber strip undergoes elastic deformation, filling all microscopic gaps between the cover and the box body to form a continuous and reliable airtight barrier. It effectively prevents the infiltration of external air and also blocks the leakage of internal inert gas, which is the basis for maintaining the oxygen-free environment in the cooling box 1 and ensuring the positive pressure displacement effect.

[0038] As a technical optimization solution of the utility model, a water chiller 104 and a water pump 502 are arranged on the outer side wall of the cooling box 1. A water outlet pipe 103 is communicated between the cooling box 1 and the water inlet end of the water chiller 104. The outer side wall of the water spray pipe 5 is communicated with a water supply pipe 501 extending to the outside of the cooling box 1. The water outlet and the water inlet end of the water pump 502 are connected to the water supply pipe 501 and the water outlet end of the water chiller 104 respectively.

[0039] In this embodiment: After the relatively warm cooling medium (water) absorbs heat from the high-temperature workpiece inside the cooling tank 1, its temperature rises. The water pump 502 draws this heated medium from the bottom of the cooling tank 1 through the outlet pipe 103 and delivers it to the chiller 104. The chiller 104, as the refrigeration core, removes the heat from the medium through its internal compressor refrigeration cycle (evaporator, compressor, condenser, expansion valve), causing it to drop back to the set temperature. The cooled medium is then pressurized by the water pump 502 and delivered through the inlet pipe 501 to the "U"-shaped spray pipe 5 installed on the side wall of the tank. The cooling medium is sprayed out from multiple outlets of the spray pipe 5 at a certain flow rate, uniformly and omnidirectionally washing the workpiece inside the mesh basket 402, achieving efficient and uniform heat exchange and preventing workpiece deformation due to uneven cooling.

[0040] As a technical optimization of this utility model, the bottom surface inside the cooling box 1 is inclined, and the outer wall of the cooling box 1 is connected to a drain pipe 101, which is equipped with a manual valve.

[0041] In this embodiment: when it is necessary to replace the cooling medium or perform equipment maintenance and cleaning, the manual valve is opened, and all the liquid in the cooling tank 1 can be drained by gravity, which ensures the cleanliness of the equipment and the convenience of maintenance.

[0042] As a technical optimization of this utility model, a heat insulation interlayer 102 is provided between the outer side wall and the inner side wall of the cooling box 1, and the interior of the heat insulation interlayer 102 is filled with heat insulation material.

[0043] In this embodiment, insulation materials such as glass wool, rock wool, or polyurethane foam can effectively block heat conduction and isolate the heat exchange between the low-temperature environment inside the cooling box 1 and the external normal-temperature environment. This reduces the cooling capacity loss of the refrigeration system, lowers the energy consumption of the chiller 104, and ensures the stability of the cooling medium temperature, making the cooling process more energy-efficient and controllable.

[0044] As a technical optimization of this utility model, support plates are fixedly installed on the left and right side walls of the cooling box 1 and the left and right side walls of the sealing cover 2. A second electric push rod 9 for driving the opening and closing of the sealing cover 2 is hinged between the two support plates on the same side.

[0045] In this embodiment, the extension and retraction of the second electric actuator 9 is directly converted into the opening and closing action of the sealing cover 2, eliminating the need for manual effort to open and close the heavy sealing cover 2.

[0046] The working principle and usage process of this utility model are as follows: A PLC controller is installed on the outer wall of the cooling box 1, so that the PLC controller is electrically connected to two second electric actuators 9, an online oxygen content analyzer 801, a flow meter 601, a liquid level sensor, a solenoid valve, and a temperature sensor 701, respectively. It can control the operation of each component and can control the two second electric actuators 9 to operate simultaneously.

[0047] In use, the PLC controller controls the second electric actuator 9 (worm gear electric actuator) to smoothly open the sealing cover 2. The operator then adds an appropriate amount of cooling medium from the cooling tank 1, ensuring the liquid level is at the level sensor, i.e., below the mesh basket 402 (the initial position of the mesh basket 402 is as follows). Figure 1 (As shown), the high-temperature workpiece treated with QPQ oxidation salt bath is then quickly placed into the mesh basket 402. The second electric actuator 9 is activated again to close the sealing cover 2. At this time, the sealing strip 201 is tightly pressed into the sealing groove 202, forming a reliable airtight seal. The solenoid valve of the air inlet pipe 6 is opened, allowing high-purity nitrogen to be introduced into the sealed cooling box 1 through the air inlet pipe 6. The flow meter 601 monitors and measures the total amount of nitrogen introduced in real time. The density of the introduced nitrogen is different from that of air, which will form an airflow, expelling the original air in the cooling box 1 from the exhaust pipe 8 located on the other side. The online oxygen content analyzer 801 installed on the exhaust pipe 8 continuously monitors the oxygen concentration of the exhaust gas. When the reading of the online oxygen content analyzer 801 stably drops to the safe threshold, it indicates that an oxygen-free environment has been successfully formed in the cooling box 1. At this time, the solenoid valve on the exhaust pipe 8 is closed to stop the introduction of a large amount of nitrogen. The pressure relief valve 7 ensures that the pressure in the cooling box 1 will not exceed the safe limit throughout the process. The first electric actuator 4 (worm gear electric actuator) is activated, driving the basket 402 carrying the workpiece to descend smoothly until the fixing plate 401 contacts the bottom of the groove 3. At this time, the workpiece in the basket 402 can be immersed in the cooling medium. The water pump 502 is started, and the cooling medium in the cooling box 1, which has been heated by the workpiece and raised in temperature, flows into the chiller 104 through the water outlet pipe 103. The chiller 104, as the core of the refrigeration, uses its compressor to quickly remove the heat of the medium through the refrigeration cycle, so that its temperature drops back to the set low temperature. The cooled medium is pressurized by the water pump 502 through the outlet of the chiller 104 and transported to the "U"-shaped spray pipe 5 through the water inlet pipe 501. Finally, it is sprayed out from many outlets at a certain pressure, evenly and gently washing each workpiece in the basket 402 from all sides.

[0048] The probe of temperature sensor 701 is immersed in the medium and transmits the temperature signal back to the PLC controller in real time to ensure that the cooling process is carried out within the preset low temperature range. When temperature sensor 701 detects that the workpiece temperature has dropped to the low temperature required by the process, the cooling process ends. The second electric push rod 9 opens the sealing cover 2, and the first electric push rod 4 lifts the mesh basket 402 and the cooled workpiece above the liquid surface to drain excess medium. Then, the operator can take out the processed workpiece.

[0049] In the description of this utility model, it should be understood that the terms "left", "right", "up", "down", "top", "bottom", "front", "back", "inner", "outer", "back", "middle", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0050] However, the above description is only a specific embodiment of this utility model and should not be construed as limiting the scope of implementation of this utility model. Therefore, any substitution of equivalent components or equivalent changes and modifications made in accordance with the scope of protection of this utility model should still fall within the scope of the claims of this utility model.

Claims

1. A rapid cooling device for workpieces after QPQ treatment, comprising a cooling tank (1), wherein a liquid level sensor is provided on the inner wall of the cooling tank (1), and a sealing cover (2) is hinged to the top of the cooling tank (1), characterized in that: The cooling tank (1) is provided with a lifting mechanism for lifting and lowering workpieces; The lifting mechanism comprises two symmetrically distributed grooves (3) formed at the top of the cooling tank (1), the bottom end surface inside the groove (3) is formed with a mounting groove (301), a first electric push rod (4) is installed inside the mounting groove (301), the output end of the first electric push rod (4) is fixedly provided with a fixing plate (401), and a mesh basket (402) located inside the cooling tank (1) is fixedly installed between the two fixing plates (401); A spray pipe (5) shaped like a Chinese character "hui" (closed loop) is fixedly installed on the inner side wall of the cooling tank (1), and the spray pipe (5) is located below the liquid level sensor and communicated with a plurality of water outlets on the side close to the mesh basket (402); An air inlet pipe (6) penetrates through and is fixedly installed at the right end of the top of the sealing cover (2), the outer side wall of the air inlet pipe (6) is sequentially provided with a solenoid valve and a flow meter (601) along the air flow direction, and one end of the air inlet pipe (6) extends into the interior of the mesh basket (402).

2. The rapid cooling device for workpieces after QPQ treatment according to claim 1, characterized in that: The top of the sealing cover (2) is provided with a pressure relief valve (7) and a temperature sensor (701) with a probe extending into the interior of the cooling tank (1), the left end of the top of the sealing cover (2) penetrates through and is fixedly connected with an exhaust pipe (8), and the outer side wall of the exhaust pipe (8) is sequentially provided with an online oxygen content analyzer (801) and a solenoid valve along the gas flow direction.

3. The rapid cooling device for workpieces after QPQ treatment according to claim 1, characterized in that: A sealing strip (201) shaped like a Chinese character "hui" (closed loop) is fixedly installed on the inner side wall of the sealing cover (2), and the top of the cooling tank (1) is formed with a sealing groove (202) matched with the sealing strip (201).

4. The rapid cooling device for workpieces after QPQ treatment according to claim 1, characterized in that: The outer side wall of the cooling tank (1) is provided with a chiller (104) and a water pump (502), a water outlet pipe (103) is communicated between the cooling tank (1) and the water inlet end of the chiller (104), the outer side wall of the spray pipe (5) is communicated with a water supply pipe (501) extending to the outside of the cooling tank (1), and the water outlet and water inlet end of the water pump (502) are connected to the water supply pipe (501) and the water outlet end of the chiller (104) respectively.

5. A rapid cooling device for workpieces after QPQ treatment according to claim 1, characterized in that: The bottom end surface inside the cooling tank (1) is arranged in an inclined manner, the outer side wall of the cooling tank (1) is communicated with a drain pipe (101), and a manual valve is arranged on the drain pipe (101).

6. The rapid cooling device for workpieces after QPQ treatment according to claim 1, characterized in that: A thermal insulation interlayer (102) is arranged between the outer side wall and the inner side wall of the cooling tank (1), and the interior of the thermal insulation interlayer (102) is filled with a thermal insulation material.

7. A rapid cooling device for workpieces after QPQ treatment according to claim 1, characterized in that: Support plates are fixedly installed on both the left and right side walls of the cooling tank (1) and the left and right side walls of the sealing cover (2), and a second electric push rod (9) for driving the opening and closing of the sealing cover (2) is hinged between the two support plates located on the same side.

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