A quenching and cooling system for box-type workpieces and a quenching and cooling method thereof

Abstract

The present invention discloses a quenching and cooling system for box-type workpieces and a quenching and cooling method thereof, and belongs to the technical field of heat treatment quenching and cooling equipment. The present invention discloses a quenching and cooling system for box-type workpieces and a quenching and cooling method thereof, comprising a quenching pool body, a stirring system, and a hoisting system capable of hoisting the workpiece for reciprocating motion, wherein the stirring device is symmetrically installed on both sides of the interior of the quenching pool body from above; a guide device is arranged between the stirring devices, and the guide device comprises multiple layers of symmetrically distributed guide plates, and the liquid flow in the quenching pool is controlled by utilizing the thrust of the propeller blades in the stirring system and the quenching liquid flow channels formed between each layer of guide plates; a circulating cooling system is also connected to the outside of the quenching pool, and when the temperature of the quenching medium is higher than the upper limit of its optimal use temperature, the circulating cooling system is started to realize the circulation and cooling of the quenching liquid.

Description

Technical Field

[0001] The invention relates to the technical field of heat treatment quenching and cooling equipment, and more specifically to a quenching and cooling system for box-type workpieces and a quenching and cooling method thereof. Background Art

[0002] The heating and cooling speeds during the heat treatment process are very important. For large workpieces, special-shaped parts, and workpieces with design defects that are not conducive to heat treatment, the heating speed must be controlled within a certain range, otherwise it will cause excessive temperature differences between different parts of the workpiece, and produce thermal stress and deformation; the cooling speed needs to be selected according to different heat treatment methods.

[0003] The cooling rates from highest to lowest are: quenching, normalizing, tempering, and annealing. c3 or A c1 The metal heat treatment process is to heat the steel to a temperature above 300°C for a period of time to completely austenitize it, and then cool it quickly. The purpose of quenching is to make the steel obtain a uniform martensitic structure. Tempering the quenched steel at different temperatures can make the steel obtain strength, hardness, wear resistance, fatigue resistance and other properties that meet the service requirements. During quenching, the workpiece is cooled in a quenching medium (such as water or oil) that undergoes a physical state change, and a steam film will form on its surface, so that the surface cannot directly contact the quenching medium. Heat can only be exchanged through the steam film, which seriously hinders the cooling of the workpiece. The temperature, flow, pressure of the quenching medium and the surface area and roughness of the workpiece will affect the cooling capacity of the quenching medium.

[0004] For large box-type workpieces such as the hydraulic end valve box of an oil fracturing pump, the flow of the quenching medium can be controlled to keep the medium in the quenching pool at a low and uniform temperature, thereby improving the cooling capacity of the quenching medium. During quenching, the uniformity of the quenching medium temperature and the cooling rate in the quenching pool determine the mechanical properties of the quenched and tempered parts, which requires the quenching stirring system to be highly efficient. At present, the stirring of quenching pools at home and abroad mostly adopts the method of installing rotating blades at the bottom of the pool and using a high-power motor to drive the blades to rotate. However, for large quenching pools, the stirring flow rate cannot meet the quenching requirements. In addition, when the bottom of the pool is used for stirring, when repairing the blades, the quenching medium in the quenching pool needs to be completely transferred, which makes the maintenance time long and difficult.

[0005] After searching, it is found that there are relevant patents disclosed to solve the above-mentioned problem of uniform temperature consistency of quenching medium. For example, the utility model patent with Chinese patent application number: 201620999428.6 and publication date: August 31, 2016 discloses a large-scale rotary diversion type high-efficiency stirring quenching pool, including several stirring systems, the stirring system includes a horizontal diversion cylinder fixedly arranged at the bottom of the quenching pool, and a vertical diversion cylinder and a stirring cylinder are fixedly connected from one end of the horizontal diversion cylinder to the top in sequence, the upper opening of the stirring cylinder is fixed with a casing through a detachable connection, and a stirring shaft connected to the casing through a bearing is arranged in the stirring cylinder, the lower end of the stirring shaft is fixedly connected with a propeller, and the upper end extends into the casing and is connected to a driving device that drives it to rotate, and a liquid inlet is provided on the stirring cylinder at a position higher than the propeller; the utility model can achieve uniform temperature of the quenching medium and ensure good quenching effect and quenching efficiency. However, the guide tube used in this device occupies a large space, which reduces the space utilization rate of the quenching pool, and each guide tube needs to be equipped with a set of stirring devices, which requires a large investment in production. In addition, the position of the guide tube is fixed, which can only play the role of stirring the quenching liquid, and has poor flushing ability for the steam film on the surface of the workpiece, and has a single function. Summary of the invention

[0006] 1. Technical problem to be solved by the invention

[0007] In view of the problems of poor fluidity and uneven temperature of quenching liquid in the quenching pool in the prior art, the present invention provides a quenching cooling system and a quenching cooling method for box-type workpieces, wherein symmetrically distributed multi-layer guide plates are used to replace the guide pipes, and quenching liquid circulation channels are formed between the layers of the guide plates, so that the cost is low, the space occupied is small, and the fire utilization efficiency of the quenching pool can be improved.

[0008] 2. Technical solution

[0009] In order to achieve the above object, the technical solution provided by the present invention is:

[0010] A quenching cooling system for box-type workpieces, comprising a quenching pool body, the quenching pool body is a rectangular parallelepiped structure with an open top and a hollow interior; the stirring device is symmetrically installed on both sides of the interior of the quenching pool body from above, and is driven by a driving device, and the driving device is installed on both sides of the top of the quenching pool body; a guide device is arranged between the stirring devices, and the guide device includes a guide plate, the guide plate is multi-layered and symmetrically distributed at the bottom of the quenching pool body, and is located below the liquid level of the quenching liquid, and the guide pipe is replaced by a symmetrically distributed multi-layer guide plate, and a quenching liquid circulation channel is formed between the layers of the guide plate. Compared with the traditional guide pipe, the guide plate has low cost and occupies less space, and can improve the fire utilization efficiency of the quenching pool.

[0011] A further technical solution is that a limiting module is detachably installed at the outlet of the quenching liquid circulation channel, and the bottom of the limiting module is arc-shaped and matched with the shape of the quenching liquid circulation channel, so as to reduce the speed loss when the liquid flow collides with the limiting module and increase the impact of the liquid flow on the steam film on the surface of the workpiece; and the upper surface of the limiting module is designed to be a plane, which can serve as a supporting platform for limiting the lowest point of the box-type workpiece in the quenching pool, thereby avoiding unnecessary losses caused by the box-type workpiece colliding with the bottom guide plate during the descent.

[0012] A further technical solution is that the stirring device is started by controlling the external control box, and the stirring device includes a connecting rod and a propeller blade, the upper end of the connecting rod is connected to the transmission on the driving device, and is driven by the motor on the driving device; in combination with the use of a multi-layer guide plate, the quenching medium can be transported to various parts of the quenching pool by the propeller blades, thereby effectively solving the problem of dead circulation zones in the quenching pool and promoting temperature uniformity in the pool; compared with the compressed air stirring method, propeller stirring can reduce the contact between the quenching liquid (especially quenching oil) and the air, and reduce the oxidation of the quenching medium; in addition, a variable speed stirring device is adopted, and different rotation speeds can be selected for quenching media of different viscosities, thereby ensuring the fluidity of the quenching medium.

[0013] According to a further technical solution, the propeller blades are airfoil-type propellers, the number of the propeller blades is 3 to 4, and the blade helical angle is 25 to 35 degrees, so as to increase the stirring effect and thus increase the flow rate of the quenching liquid.

[0014] A further technical solution also includes a lifting system, which includes a guide rail, which is symmetrically arranged on the outer side of the quenching pool body and fixedly installed along the length direction of the quenching pool body; a cylinder is movably connected to the guide rail along its length direction, and a suspension is fixedly installed above the cylinder. The suspension is mounted above the quenching pool body, and a hook is also fixedly installed on the suspension, and the hook is used to lift the box-type workpiece; the lifting system can reciprocate in the horizontal and vertical directions. After the box-type workpiece is suspended on the suspension, its depth in the quenching pool is controlled by the cylinder, and its horizontal movement is controlled by the guide rail. The circulation of the quenching liquid and the reciprocating motion of the box-type workpiece are utilized to enhance the effect of removing the steam film, thereby accelerating the cooling rate of the box-type workpiece.

[0015] A further technical solution is that the quenching pool body is also externally connected to a circulating cooling system, which includes a cooling pool, and the cooling pool is connected to a filter I provided at the bottom of the quenching pool body through an external drain pipe, so that the high-temperature quenching liquid in the quenching pool can be discharged into the cooling pool at a certain flow rate by relying on its own weight under the control of the flow control valve. The high-temperature quenching liquid flows from the quenching pool into the cooling pool for cooling and is used for the next round of temperature regulation. By adding a filter I to the drain pipe, the cleanliness of the quenching medium is ensured, and mechanical impurities in the quenching medium can be prevented from blocking the pipeline.

[0016] A further technical solution is that the cooling pool is also externally connected to a liquid extraction pipe, the liquid extraction port of the liquid extraction pipe is connected to the quenching pool body, and the quenching liquid in the cooling pool can be discharged into the quenching pool body through the liquid extraction pipe; a filter II and a liquid extraction pump are respectively arranged in the middle of the liquid extraction pipe near one end of the cooling pool; when the temperature of the quenching liquid in the quenching pool body is too high, the liquid extraction pump is used to extract the low-temperature quenching liquid in the quenching pool body into the cooling pool through the liquid extraction pipe, thereby cooling the quenching pool; the quenching liquid in the cooling pool is cooled by a circulating cooling system, and a filter II is added to the liquid extraction pipe to ensure the cleanliness of the quenching medium and prevent mechanical impurities in the quenching medium from blocking the pipeline.

[0017] A further technical solution is that a cooling water pipe is provided inside the cooling pool, one end of the cooling water pipe is connected to a water tank, and the other end is connected to a water pump; the high-temperature quenching liquid flowing into the cooling pool from the quenching pool body is concentrated around the cooling water pipe, and the water pump is started to draw water from the water tank so that the cooling water pipe is filled with cooling water, thereby cooling the high-temperature quenching liquid.

[0018] A further technical solution is that a temperature sensor is also provided in the quenching pool body. The temperature sensor is located at the outlet of the quenching liquid circulation channel and below the liquid level of the quenching liquid. The temperature displayed by the temperature sensor is observed. When the temperature of the quenching medium is higher than its upper limit of the optimal operating temperature, the circulating cooling system is started to reduce the temperature of the quenching liquid in the quenching pool and improve the cooling efficiency of the quenching medium.

[0019] A quenching and cooling method for a box-type workpiece, comprising the following steps:

[0020] Step 1: Lift the box-type workpiece: Use the lifting system to lift the box-type workpiece, move the cylinder along the length of the guide rail until the box-type workpiece is aligned with the quenching pool opening, start the cylinder to drive the suspension to move down until the box-type workpiece is completely submerged below the quenching liquid level;

[0021] Step 2, quenching cooling: by starting the control box to drive the motor to drive the stirring device, the propeller blades in the stirring device start to rotate and stir, so that the quenching liquid in the quenching pool circulates, and the quenching medium flows in the quenching liquid flow channel formed between the guide plate and the restriction module, and impacts the surface of the workpiece to quickly rupture the steam film;

[0022] Step 3: Adjust the quenching liquid temperature: When the temperature sensor detects that the temperature in the pool is higher than the upper limit of the optimal use temperature of the corresponding quenching medium, turn on the liquid pump to inject low-temperature quenching medium into the pool. The low-temperature quenching medium is fully mixed with the quenching liquid medium in the quenching pool under the control of the propeller blades and the guide device, so that the temperature in the pool tends to be stable;

[0023] Step 4: Quenching liquid cooling cycle: Open the flow control valve and discharge the same volume of quenching liquid as when it was injected into the cooling pool. The quenching medium entering the cooling pool is cooled by circulating water and can be used for the next round of quenching pool temperature adjustment.

[0024] 3. Beneficial effects

[0025] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0026] (1) A quenching and cooling system for box-type workpieces and a quenching and cooling method thereof of the present invention use symmetrically distributed multi-layer guide plates to replace the guide pipes, and use the thrust of the propeller blades and the quenching liquid flow channel formed between the guide plates and the limiting module to control the liquid flow in the quenching pool, so that the liquid flow in the quenching pool forms a bottom-up liquid flow pattern, and the rising liquid flow can impact the steam film on the surface of the large workpiece, so that the steam film breaks quickly, thereby increasing the wetting speed of the workpiece and improving the quenching efficiency; compared with the traditional guide pipe, the guide plate has low cost and occupies less space, which can improve the utilization rate of the quenching pool; in addition, the multi-layer guide plate can transport the medium driven by the propeller to various parts in the quenching pool, effectively solving the problem of the circulation dead zone in the quenching pool and promoting the temperature uniformity in the pool; compared with the method of compressed air stirring, the propeller stirring can reduce the contact between the quenching liquid (especially the quenching oil) and the air, and reduce the oxidation of the quenching medium;

[0027] (2) A quenching cooling system and a quenching cooling method for a box-type workpiece of the present invention, wherein the upper surface of the limiting module is horizontal, and the bottom thereof is arc-shaped and matches the shape of the quenching liquid flow channel, thereby reducing the width of the guide plate liquid flow outlet. When the propeller thrust remains unchanged, the flow rate of the liquid flow remains unchanged. Reducing the outlet width can increase the liquid flow velocity at the liquid flow outlet, reduce the speed loss when the liquid flow collides with the limiting module, and increase the impact of the liquid flow on the steam film on the surface of the workpiece; the upper surface of the limiting module is designed to be a plane and can serve as a support platform for limiting the lowest point of the box-type workpiece in the quenching pool, thereby avoiding unnecessary losses caused by the box-type workpiece colliding with the bottom guide plate during the descent process;

[0028] (3) A quenching and cooling system and a quenching and cooling method for a box-type workpiece of the present invention, wherein the hoisting system can drive the workpiece to reciprocate in the horizontal and vertical directions. After the workpiece is suspended on the suspension, the cylinder is used to control its depth in the quenching pool, and the guide rail is used to control its movement in the horizontal direction. The circulation of the quenching liquid and the reciprocating motion of the workpiece can enhance the effect of removing the steam film, which is more conducive to accelerating the cooling rate of large workpieces.

[0029] (4) A quenching and cooling system for a box-type workpiece and a quenching and cooling method thereof of the present invention use a plurality of symmetrically distributed top-mounted propeller blades to drive the liquid flow, effectively overcoming the disadvantage that the bottom-mounted propeller blades may be covered by oxide scale, slag, etc. on the large workpiece;

[0030] (5) A quenching and cooling system for a box-type workpiece and a quenching and cooling method thereof of the present invention adopts a variable speed stirring device, and different speeds can be selected for quenching media of different viscosities, thereby ensuring the fluidity of the quenching medium;

[0031] (6) In a quenching and cooling system for a box-type workpiece and a quenching and cooling method thereof of the present invention, the propeller blades are selected to be airfoil-type propellers, the number of the propeller blades is 3 to 4, and the blade helical angle is 25 to 35°. The two act synergistically to effectively increase the stirring effect, thereby increasing the circulation flow rate of the quenching liquid;

[0032] (7) A quenching cooling system and a quenching cooling method for a box-type workpiece of the present invention, by observing the temperature displayed by the temperature sensor, when the temperature of the quenching medium is higher than the upper limit of its optimal use temperature, the circulating cooling system is started to reduce the temperature in the quenching pool and improve the cooling efficiency of the quenching medium;

[0033] (8) The quenching cooling system and quenching cooling method for box-type workpieces of the present invention, the circulating cooling system not only has the effect of accelerating the cooling of the high-temperature quenching medium, but also performs two filtering procedures on the quenching medium by adding filter I and filter II during the circulation process. On the one hand, it can prevent mechanical impurities in the quenching medium from blocking the pipeline, and on the other hand, it can also ensure the cleanliness of the quenching medium. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the structure of the quenching cooling system of the present invention;

[0035] Figure 2 It is a schematic diagram of the left side cross-sectional structure of the quenching tank body of the present invention;

[0036] Figure 3 This is a schematic diagram of the internal structure of the cooling pool in the present invention from a top view;

[0037] Figure 4 It is a schematic diagram of the internal structure of the cooling pool in the present invention from the right side.

[0038] In the figure: 1-quenching pool body; 2-driving device; 3-stirring device; 4-guiding device; 5-hoisting system; 6-circulating cooling system; 7-control box; 8-temperature sensor; 9-box workpiece; 10-quenching liquid level; 11-filter I; 12-drain pipe; 13-flow control valve; 21-motor; 22-transmission; 31-connecting rod; 32-propeller blade; 40-quenching liquid flow channel; 41-guide plate; 42-restriction module; 51-cylinder; 52-guide rail; 53-suspension; 54-hook; 61-cooling pool; 62-water tank; 63-cooling water pipe; 64-water pump; 65-liquid pump; 66-filter II; 67-liquid suction pipe. DETAILED DESCRIPTION

[0039] In order to further understand the content of the present invention, the invention is described in detail with reference to the accompanying drawings.

[0040] Example 1

[0041] A quenching cooling system for a box-type workpiece according to this embodiment, such as Figure 1 As shown, it includes a quenching pool body 1, and the quenching pool body 1 is a rectangular parallelepiped structure with an open top and a hollow interior; Figure 2As shown, the stirring device 3 is symmetrically installed on both sides of the quenching tank body 1 from above, and is driven by a driving device 2, and the driving device 2 is installed on both sides of the top of the quenching tank body 1; a guide device 4 is arranged between the stirring devices 3, and the guide device 4 includes a guide plate 41, and the guide plates 41 are symmetrically distributed in three layers at the bottom of the quenching tank body 1 and are located below the height of the quenching liquid level 10. The guide pipe is replaced by a symmetrically distributed multi-layer guide plate 41, and a quenching liquid circulation channel 40 is formed between each layer of the guide plate 41. Compared with the traditional guide pipe, the guide plate 41 has low cost and occupies less space, which can improve the utilization rate of the quenching tank.

[0042] Example 2

[0043] The quenching cooling system for box-type workpieces in this embodiment has the same basic structure as that in embodiment 1, except that: Figure 2 As shown, a limiting module 42 of corresponding height is provided at the outlet of each layer of guide plate 41 according to its depth. The limiting module 42 is detachably installed at the outlet of the quenching liquid circulation channel 40. The bottom of the limiting module 42 is arc-shaped and matched with the shape of the quenching liquid circulation channel 40 to reduce the speed loss when the liquid flow collides with the limiting module 42 and increase the impact of the liquid flow on the steam film on the surface of the workpiece; and the upper surface of the limiting module 42 is designed to be a plane, which can serve as a supporting platform for limiting the lowest point of the box-type workpiece 9 in the quenching pool, so as to avoid unnecessary losses caused by the box-type workpiece 9 colliding with the bottom guide plate 41 during the descent.

[0044] Example 3

[0045] The quenching cooling system for box-type workpieces in this embodiment has the same basic structure as that in Embodiment 2, except that: Figure 2 As shown, the stirring device 3 is controlled and started by an external control box 7. The stirring device 3 includes a connecting rod 31 and a propeller blade 32. The number of blades of the propeller blade 32 is 3 to 4, and the blade spiral angle is 25 to 35 degrees. The propeller blade 24 uses a wing-shaped propeller to achieve a better stirring effect, thereby increasing the circulation flow rate of the quenching liquid; the upper end of the connecting rod 31 is connected to the transmission 22 on the drive device 2 and driven by the motor 21 on the drive device 2; the multi-layer guide plate 41 is used in conjunction with the propeller blade 32, and the propeller blade 32 is directly opposite to the surface of the arc-shaped guide plate 41. The quenching medium can be transported to various parts of the quenching pool through the propeller blade 32, thereby effectively solving the problem of the circulation dead zone in the quenching pool and promoting the temperature in the pool to be uniform; compared with the method of compressed air stirring, propeller stirring can reduce the contact between the quenching liquid (especially the quenching oil) and the air, and reduce the oxidation of the quenching medium; in addition, a variable speed stirring device is used, and different rotation speeds can be selected for quenching media of different viscosities, thereby ensuring the fluidity of the quenching medium.

[0046] Example 4

[0047] The quenching cooling system for box-type workpieces in this embodiment has the same basic structure as that in embodiment 3, except that: Figure 1 As shown, it also includes a lifting system 5, which includes a guide rail 52, which is symmetrically arranged on the outer side of the quenching pool body 1 and fixedly installed along the length direction of the quenching pool body 1; a cylinder 51 is movably connected to the guide rail 52 along its length direction, and a suspension 53 is fixedly installed above the cylinder 51. The suspension 53 is erected above the quenching pool body 1, and a hook 54 is also fixedly installed on the suspension 53. The hook 54 is used to lift the box After adjusting the cylinder 51 and the suspension 53 to the appropriate position, the oil fracturing pump valve box to be processed is hoisted on the suspension hook 54 with an iron chain using a crane, and the cylinder 51 is controlled to descend so that the oil fracturing pump valve box is immersed in the quenching pool to below the liquid level 10, and then the cylinder 51 is controlled to reciprocate horizontally along the guide rail 52. The effect of strengthening the removal of the steam film is achieved through the circulation of the quenching liquid and the reciprocating motion of the oil fracturing pump valve box, which is more conducive to accelerating the cooling rate of the oil fracturing pump valve box.

[0048] Example 5

[0049] The quenching cooling system for box-type workpieces in this embodiment has the same basic structure as that in embodiment 4, except that: Figure 1 , 2 As shown, the quenching pool body 1 is also externally connected to a circulating cooling system 6, and the circulating cooling system 6 includes a cooling pool 61, and the cooling pool 61 is connected to the filter Ⅰ11 provided at the bottom of the quenching pool body 1 through an external drain pipe 12, so that the high-temperature quenching liquid in the quenching pool can be discharged into the cooling pool at a certain flow rate by relying on its own weight under the control of the flow control valve 13; the cooling pool 61 is also externally connected to a suction pipe 67, the suction port of the suction pipe 67 is connected to the cooling pool 61, and the discharge port of the suction pipe 67 is connected to the quenching pool body 1, and the low-temperature quenching liquid in the cooling pool 61 can be discharged into the quenching pool body 1 through the suction pipe 67 ; A filter II 66 and a liquid pump 65 are respectively provided at one end of the middle part of the liquid extraction pipe 67 near the cooling pool 61; when the temperature of the quenching liquid in the quenching pool body 1 is too high, the liquid extraction pump 65 is used to extract the low-temperature quenching liquid in the quenching pool body 1 into the cooling pool 61 through the liquid extraction pipe 67, so as to cool the quenching liquid in the quenching pool; when the temperature reaches the appropriate range, stop adding the low-temperature quenching liquid, open the flow control valve 13, and discharge the same volume of quenching liquid in the quenching pool body 1 into the cooling pool 61. After the quenching liquid is discharged into the cooling pool 61, the circulating cooling system 6 is used to complete the cooling of the quenching liquid, and after cooling, it is used for the next round of temperature regulation.

[0050] In this embodiment, the circulating cooling system 6 not only has the effect of accelerating the cooling of the high-temperature quenching medium, but also performs two filtering procedures on the quenching medium by adding filter I11 and filter II66 during the circulation process. On the one hand, it can prevent mechanical impurities in the quenching medium from blocking the pipeline, and on the other hand, it can also ensure the cleanliness of the quenching medium.

[0051] Example 6

[0052] The quenching cooling system for box-type workpieces in this embodiment has the same basic structure as that in Embodiment 5, except that: Figure 3 , 4 As shown, a cooling water pipe 63 is provided inside the cooling pool 61, one end of the cooling water pipe 63 is connected to a water tank 62, and the other end is connected to a water pump 64; the high-temperature quenching liquid flowing from the quenching pool body 1 into the cooling pool 61 is concentrated around the cooling water pipe 63, and the water pump 64 is started to extract water from the water tank 62, so that the cooling water pipe 63 is filled with cooling water, thereby cooling the high-temperature quenching liquid; since the water tank 62 and the water pump 64 are arranged outside the cooling pool 61, there is only a ring-circulating cooling water pipe 63 inside the cooling pool 61, thereby ensuring that the high-temperature quenching liquid can be fully and quickly cooled, and there is enough capacity in the cooling pool 61 to hold the quenching liquid.

[0053] Example 7

[0054] The quenching cooling system of the present embodiment is used for box-type workpieces. The basic structure is the same as that of the embodiment 6. The difference and improvement are as follows: Figure 2 As shown, a temperature sensor 8 is also provided in the quenching pool body 1, and the temperature sensor 8 is located at the outlet of the quenching liquid circulation channel 40 and below the height of the quenching liquid level 10. The temperature displayed by the temperature sensor 8 is observed. When the temperature of the quenching medium is higher than the upper limit of its optimal use temperature, the circulating cooling system 6 is started to reduce the temperature of the quenching liquid in the quenching pool and improve the cooling efficiency of the quenching medium.

[0055] In this embodiment, for a quenching medium (such as a polymer aqueous solution) whose temperature rises and whose cooling capacity decreases, an upper limit of the temperature in the pool can be set according to its optimal quenching temperature.

[0056] Example 8

[0057] The quenching cooling method for a box-type workpiece in this embodiment has the same basic structure as that in Embodiment 7, except that: Figure 1 , 2 As shown, the steps are as follows:

[0058] Step 1: Lifting the box-type workpiece 9: Use the lifting system 5 to lift the box-type workpiece 9, move the cylinder 51 along the length direction of the guide rail 52 until the box-type workpiece 9 is aligned with the quenching pool opening, start the cylinder 51 to drive the suspension 53 to move downward until the box-type workpiece 9 is completely immersed in a position below the height of the quenching liquid level 10;

[0059] Step 2: quenching and cooling: by starting the control box 7 to drive the motor 21 to drive the stirring device 3, the propeller blades 32 in the stirring device 3 start to rotate and stir, so that the quenching liquid in the quenching pool circulates, and the quenching medium flows in the quenching liquid flow channel 40 formed between the guide plate 41 and the limiting module 42, and impacts the surface of the workpiece to quickly rupture the steam film;

[0060] Step 3: Regulating the quenching liquid temperature: When the temperature sensor 8 detects that the temperature in the pool is higher than the upper limit of the optimal use temperature of the corresponding quenching medium, the liquid pump 65 is turned on to inject the low-temperature quenching medium into the pool. The low-temperature quenching medium is fully mixed with the quenching liquid medium in the quenching pool under the control of the propeller blades 32 and the guide device 4, so that the temperature in the pool tends to be stable;

[0061] Step 4: Quenching liquid cooling cycle: Open the flow control valve 13 to discharge the same volume of quenching liquid as that injected into the cooling pool 61. The quenching medium entering the cooling pool 61 is cooled by circulating water and used for the next round of quenching pool temperature adjustment.

[0062] In this embodiment, compared with the use of an ordinary quenching pool, the Rockwell hardness of the surface of the oil fracturing pump valve box quenched by the quenching system of the present invention is increased by an average of 2HRC, the surface hardness uniformity is greatly improved, no soft spots occur, and the distortion of the workpiece is greatly reduced.

[0063] The present invention and its embodiments are described schematically above, and the description is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. Therefore, if a person skilled in the art is inspired by it and designs a structural method and an embodiment similar to the technical solution without creativity without departing from the purpose of the invention, they shall all fall within the protection scope of the present invention.

Claims

1. A quenching and cooling system for box-type workpieces, comprising a quenching pool body (1), characterized in that: The stirring device (3) is symmetrically installed on both sides of the quenching tank body (1) from above and driven by a driving device (2), wherein the driving device (2) is installed on both sides of the top of the quenching tank body (1); a flow guide device (4) is arranged between the stirring devices (3), and the flow guide device (4) comprises a flow guide plate (41), wherein the flow guide plates (41) are arranged in multiple layers and symmetrically distributed at the bottom of the quenching tank body (1) and are located below the height of the quenching liquid surface (10), and a quenching liquid circulation channel (40) is formed between each layer of the flow guide plates (41); A limiting module (42) is detachably mounted at the outlet of the quenching liquid circulation channel (40), and the height of the limiting module (42) corresponds to the outlet depth of each layer of guide plate (41); the upper surface of the limiting module (42) is horizontal, and its bottom is arc-shaped and matches the shape of the quenching liquid circulation channel (40).

2. A quenching and cooling system for box-type workpieces according to claim 1, characterized in that: The stirring device (3) is controlled and started by an external control box (7). The stirring device (3) comprises a connecting rod (31) and a propeller blade (32). The upper end of the connecting rod (31) is drivingly connected to a transmission (22) on the driving device (2) and is driven by a motor (21) on the driving device (2).

3. A quenching and cooling system for box-type workpieces according to claim 2, characterized in that: The number of the propeller blades (32) is 3 to 4, and the blade helical angle is 25 to 35 degrees.

4. A quenching and cooling system for box-type workpieces according to claim 3, characterized in that: The invention also comprises a lifting system (5), wherein the lifting system (5) comprises a guide rail (52), wherein the guide rail (52) is symmetrically arranged on the outer side surface of the quenching pool body (1) and is fixedly installed along the length direction of the quenching pool body (1); a cylinder (51) is movably connected to the guide rail (52) along its length direction, a suspension (53) is fixedly installed above the cylinder (51), the suspension (53) is mounted above the quenching pool body (1), and a hook (54) is also fixedly installed on the suspension (53), and the hook (54) is used to lift the box-type workpiece (9).

5. A quenching and cooling system for box-type workpieces according to claim 4, characterized in that: The quenching pool body (1) is also externally connected to a circulating cooling system (6), wherein the circulating cooling system (6) comprises a cooling pool (61), wherein the cooling pool (61) is connected to a filter I (11) provided at the bottom of the quenching pool body (1) via an externally connected drain pipe (12), and the high-temperature quenching liquid in the quenching pool can be discharged into the cooling pool under the control of a flow control valve (13).

6. A quenching and cooling system for box-type workpieces according to claim 5, characterized in that: The cooling pool (61) is also externally connected to a liquid extraction pipe (67); the liquid extraction port of the liquid extraction pipe (67) leads into the cooling pool (61), and the liquid discharge port thereof leads into the quenching pool body (1); the quenching liquid in the cooling pool (61) can be discharged into the quenching pool body (1) through the liquid extraction pipe (67); a filter II (66) and a liquid extraction pump (65) are respectively arranged at one end of the middle portion of the liquid extraction pipe (67) close to the cooling pool (61).

7. A quenching and cooling system for box-type workpieces according to claim 6, characterized in that: A cooling water pipe (63) is provided inside the cooling pool (61), one end of the cooling water pipe (63) leads to a water tank (62), and the other end is connected to a water pump (64).

8. A quenching and cooling system for box-type workpieces according to claim 7, characterized in that: A temperature sensor (8) is also provided in the quenching pool body (1), and the temperature sensor (8) is located at the outlet of the quenching liquid circulation channel (40) and below the height of the quenching liquid level (10).

9. A method for quenching and cooling a box-type workpiece using the quenching and cooling system according to claim 8, characterized in that: The following steps are involved: Step 1, hoisting the box-type workpiece (9): hoist the box-type workpiece (9) using the hoisting system (5), move the cylinder (51) along the length direction of the guide rail (52) until the box-type workpiece (9) is aligned with the quenching pool opening, start the cylinder (51) to drive the suspension (53) to move downward until the box-type workpiece (9) is completely immersed in a position below the height of the quenching liquid surface (10); Step 2, quenching and cooling: by starting the control box (7) to drive the motor (21) to drive the stirring device (3), the propeller blades (32) in the stirring device (3) start to rotate and stir, so that the quenching liquid in the quenching pool circulates, and the quenching medium flows in the quenching liquid flow channel (40) formed between the guide plate (41) and the limiting module (42), and impacts the surface of the workpiece to quickly rupture the steam film; Step 3: Regulating the temperature of the quenching liquid: When the temperature sensor (8) detects that the temperature in the pool is higher than the upper limit of the optimal use temperature of the corresponding quenching medium, the liquid pump (65) is turned on to inject the low-temperature quenching medium into the pool. The low-temperature quenching medium is fully mixed with the quenching liquid medium in the quenching pool under the control of the propeller blades (32) and the guide device (4), so that the temperature in the pool tends to be stable. Step 4: quenching liquid cooling cycle: open the flow control valve (13) to discharge the same volume of quenching liquid as that injected into the cooling pool (61). The quenching medium entering the cooling pool (61) is cooled by circulating water and then used for the next round of quenching pool temperature regulation.

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