A process for changing quenching temperature according to workpiece diameter

Abstract

The application provides a quenching temperature changing process according to workpiece diameters, and relates to the field of metal heat treatment. The quenching temperature changing process according to workpiece diameters comprises the following steps: step one, measuring and calculating the diameter of a spherical workpiece; step two, first obtaining the time for the workpiece to pass through a high-frequency heating coil, and then according to the material of the workpiece, obtaining the heat generated by the workpiece per unit time per unit current, and combining a quenching process to calculate the current size used for the workpiece to reach a specified quenching depth and quenching temperature; step three, after the workpiece is heated for the first time, the workpiece is sent into an even-temperature chamber; step four, the workpiece in the even-temperature chamber is taken out and placed in a quenching liquid for treatment. The quality of quenching is improved through accurate control of quenching conditions and even-temperature treatment of the workpiece.

Description

Technical Field

[0001] This invention relates to the field of metal heat treatment technology, specifically a process for changing the quenching temperature according to the diameter of the workpiece. Background Technology

[0002] Grinding balls act as grinding media, crushing and grinding materials such as ores, limestone, and coal within the ball mill through self-grinding and mutual impact friction. Therefore, high surface hardness is required for the grinding balls, and quenching is a common method to improve surface hardness.

[0003] In existing grinding ball quenching processes, the grinding balls are mostly placed in a quenching furnace for overall heating. Generally, the entire grinding ball is heated, meaning even the core is heated to the required quenching temperature. During quenching, the significant temperature difference between the inside and outside causes stress concentration, making the grinding ball surface prone to cracking or breakage during impacts in later use. Furthermore, heating the entire grinding ball consumes more energy, resulting in high energy consumption. Summary of the Invention

[0004] (a) Technical problems to be solved

[0005] To address the shortcomings of existing technologies, this invention provides a process for changing the quenching temperature according to the workpiece diameter, which solves the problems of high energy consumption and poor quality caused by stress concentration in existing grinding ball quenching processes.

[0006] (II) Technical Solution

[0007] To achieve the above objectives, the present invention provides the following technical solution: a process for changing the quenching temperature according to the workpiece diameter, comprising the following steps:

[0008] Step 1: Calculate the diameter of the spherical workpiece to determine the amount of heat required to reach the quenching temperature of the spherical workpiece. At this time, it is also necessary to know the material of the spherical workpiece to obtain its specific heat capacity.

[0009] Step 2: First, obtain the time it takes for the workpiece to pass through the high-frequency heating coil. This time can be adjusted manually. Second, based on the material of the workpiece, obtain the heat generated by the workpiece per unit time and per unit current. Combined with the quenching process, calculate the current required for the workpiece to reach the specified quenching depth and quenching temperature.

[0010] Step 3: After the workpiece is heated for the first time, a non-contact temperature sensor can be used to obtain the temperature of the workpiece during the initial heating process. By obtaining the temperature of the workpiece, the current can be finely adjusted during the heating process so that the workpiece can obtain the optimal quenching temperature. The workpiece is then sent into the uniform temperature chamber. During the process of the workpiece passing through the high-frequency heating coil, because the workpiece is spherical, the temperature of the outermost part of the workpiece is high, while the temperature of the lower and upper parts is lower. Therefore, uniform heat treatment is required. The temperature of the chamber is 50-100°C higher than the quenching temperature, and the time is controlled to be less than 10 seconds to avoid the temperature of the center of the workpiece being too high, which would cause internal stress concentration during quenching and cause the surface of the workpiece to crack.

[0011] Step 4: Remove the workpiece from the equalization chamber, place it in the quenching liquid for treatment, and then let it cool naturally after taking it out.

[0012] Preferably, the quenching fluid is a water-soluble quenching medium.

[0013] A device for adjusting the quenching temperature according to the workpiece diameter includes a heating device and a quenching tank. The quenching tank is placed on one side of the heating device. The heating device includes a housing, with a second chute inclinedly arranged at the upper center of the housing. A discharge port is located at the lower part of the second chute, and a coil is arranged below the discharge port. A first chute is inclinedly arranged inside the housing, with an electrically heated heat spreader fixedly connected to the middle of the first chute. One end of the first chute is located directly below the coil. The workpiece is placed in the second chute and rolls to the discharge port under gravity, then falls onto the first chute, passing through the coil during the process to achieve heating. The workpiece then rolls from the first chute into the quenching tank, passing through the heat spreader during the process to uniformly heat the workpiece.

[0014] A baffle is slidably installed at the material discharge port. A rack is fixedly connected to the upper end of the baffle, and a servo motor equipped with an encoder is fixedly connected to the upper end of the housing. A gear is fixedly connected to the output end of the servo motor, and the gear and rack are meshed. The baffle is used to block the material discharge port, allowing individual workpieces to pass through the port sequentially for heating. Simultaneously, the servo motor controls the movement of the baffle via gear and rack transmission. The encoder on the servo motor facilitates control of the baffle's movement distance. If a trigger switch is installed on the baffle, the electrical signal of the trigger switch changes after the workpiece falls from the discharge port. Combined with the information from the encoder, the diameter of the falling workpiece can be calculated, and the required heating conditions can be adaptively set for workpieces of different diameters requiring quenching.

[0015] Preferably, a hydraulic cylinder is fixedly connected to the lower end of the outer casing, and a hydraulic rod extends from the upper end of the hydraulic cylinder, passing through the first chute upwards and located directly below the coil. An arc-shaped groove is provided at the upper end of the hydraulic rod. When the hydraulic cylinder actuates, the hydraulic rod rises to the material discharge port, and the groove at the upper end of the hydraulic rod catches the workpiece to prevent it from falling. Simultaneously, the hydraulic rod is made of ceramic to prevent induction heating.

[0016] Preferably, a push rod is fixedly connected to the first chute, the push rod being located at a high point in the first chute and close to the hydraulic rod. As the hydraulic rod descends, the push rod abuts against the workpiece and pushes the workpiece from above the hydraulic rod onto the first chute.

[0017] Preferably, both sides of the upper end of the baffle are threaded with fixing bolts, and the lower ends of the fixing bolts abut against the outer shell. When needed, the fixing bolts can be rotated to abut against the outer shell to fix the baffle. A slider is provided in the middle of the baffle, and the slider slides in a groove preset in the side wall of the second chute.

[0018] Preferably, support plates are fixedly connected to both sides of the lower end of the outer casing. These plates are used to support the outer casing.

[0019] Preferably, the side wall of the outer casing is provided with a discharge port, and one end of the first chute is assumed to be on the discharge port, which faces the quenching tank. That is, after the workpiece is heated, it rolls directly from the first chute into the quenching tank for quenching treatment.

[0020] (III) Beneficial Effects

[0021] This invention provides a process for changing the quenching temperature according to the workpiece diameter. It has the following beneficial effects:

[0022] 1. This invention, based on the size and material of the grinding ball and the quenching process, employs high-frequency rapid heating followed by uniform temperature treatment. This not only avoids stress concentration caused by excessively high internal temperature of the grinding ball, but also helps reduce energy consumption. It eliminates the need to heat the entire grinding ball; only the workpiece needs to be heated to the quenching depth.

[0023] 2. The present invention is equipped with a baffle, which can control the falling of the workpiece in sequence, and can obtain the size of the heated workpiece in conjunction with an encoder.

[0024] 3. In this invention, the heating structure is placed inside the outer shell to reduce heat dissipation, and electric heating is used, which is cleaner and more environmentally friendly than fuel heating. Attached Figure Description

[0025] Figure 1 This is a three-dimensional schematic diagram of the present invention;

[0026] Figure 2 This is a schematic diagram of the internal structure of the heating device of the present invention;

[0027] Figure 3 This is a perspective view of the heating device of the present invention from a second angle;

[0028] Figure 4 for Figure 3 Enlarged view of point A in the middle;

[0029] Figure 5 This is a three-dimensional schematic diagram of one side of the hydraulic rod of the present invention.

[0030] The components include: 1. Heating device; 2. Quenching tank; 3. Outer shell; 4. Coil; 5. Heat dissipation pipe; 6. Support plate; 7. First chute; 8. Discharge port; 9. Second chute; 10. Hydraulic cylinder; 11. Fixing bolt; 12. Baffle; 13. Rack; 14. Servo motor; 15. Gear; 16. Discharge port; 17. Push rod; 18. Hydraulic rod. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0032] Example 1:

[0033] This invention provides a process for changing the quenching temperature according to the workpiece diameter, including the following steps:

[0034] Step 1: Calculate the diameter of the spherical workpiece. In addition to this, it is also necessary to obtain the thermal conductivity and specific heat capacity of the workpiece to facilitate the subsequent quenching process, so as to control the heating time and heating intensity.

[0035] Step Two: First, obtain the time it takes for the workpiece to pass through the high-frequency heating coil. The speed at which the workpiece passes through the high-frequency heating coil can be set manually to avoid the free fall speed being too fast, which would prevent the specified heating temperature from being reached. Second, based on the material of the workpiece, obtain the heat generated by the workpiece per unit time per unit current, that is, obtain the induction heating rate. Combined with the quenching process, calculate the current required for the workpiece to reach the specified quenching depth and quenching temperature. Based on this theoretical value, in the actual heating process, a non-contact temperature sensor can be used to obtain the current temperature of the workpiece and fine-tune the current to achieve the optimal heating temperature for the workpiece.

[0036] Step 3: After the workpiece is heated for the first time, it is sent into the uniform temperature chamber. When the workpiece is induction heated, the surface of the workpiece is not heated evenly due to the shape of the sphere, which is not conducive to subsequent quenching. Therefore, the workpiece is subjected to uniform heat treatment, and the temperature of the chamber is 50-100°C higher than the quenching temperature. The time is controlled to be less than 10 seconds. If the workpiece stays in the uniform temperature chamber for too long, the temperature at the center of the sphere will be too high, which will cause stress concentration.

[0037] Step 4: Remove the workpiece from the equalization chamber and place it in the quenching liquid for treatment.

[0038] The quenching fluid uses a water-soluble quenching medium.

[0039] Example 2:

[0040] Based on Embodiment 1, this embodiment proposes a device for changing the quenching temperature according to the workpiece diameter, such as... Figure 1-5 As shown, the device includes a heating device 1 and a quenching tank 2. The heating device 1 is a cuboid structure. The quenching tank 2 is placed on one side of the heating device 1, so that the heated workpiece can fall directly into the quenching tank 2. The heating device 1 includes a shell 3. A second chute 9 is inclinedly arranged in the middle of the upper end of the shell 3. The inclined second chute 9 facilitates the workpiece to roll from top to bottom. A discharge port 16 is provided at the lower part of the second chute 9. When the workpiece rolls to the discharge port 16, it can enter the interior of the shell 3 for heating treatment. A coil 4 is provided below the discharge port 16. The coil 4 is used for inductive heating of the workpiece. The workpiece entering from the discharge port 16 will pass through the coil 4. A first chute 7 is inclinedly arranged inside the shell 3. The first chute 7 is used to receive the heated workpiece. An electric heating type heat spreader 5 is fixedly connected to the middle of the first chute 7. The heat spreader 5 generates heat after being energized. The workpiece passing through is not reheated. Since the workpiece rolls through, the uniformity of the workpiece surface temperature can be improved. One end of the first chute 7 is located directly below the coil 4.

[0041] A baffle 12 is slidably installed at the discharge port 16. A slider is provided in the middle of both sides of the baffle 12. The slider slides and engages with the groove provided on the side wall of the second chute 9. The baffle 12 is used to block the discharge port 16 and control the workpiece to pass through the discharge port 16 one by one. A rack 13 is fixedly connected to the upper end of the baffle 12. A servo motor 14 with an encoder is fixedly connected to the upper end of the housing 3. A gear 15 is fixedly connected to the output end of the servo motor 14. The gear 15 and the rack 13 are meshed. When the servo motor 14 is started, the baffle 12 can slide through the transmission of the gear 15 and the rack 13. The servo motor 14 is equipped with an encoder, which can accurately control the distance the baffle 12 moves.

[0042] A hydraulic cylinder 10 is fixedly connected to the lower end of the outer casing 3. The upper end of the hydraulic cylinder 10 passes through the outer casing 3. A hydraulic rod 18 extends from the upper end of the hydraulic cylinder 10 and passes through the first chute 7. The hydraulic rod 18 is located directly below the coil 4. When the hydraulic cylinder 10 is working, the hydraulic rod 18 is lifted, and its upper end rises to the material drop port 16 to catch the falling workpiece. The working power of the hydraulic cylinder 10 is provided by an external hydraulic source, or the hydraulic source can be fixed below the outer casing 3. The upper end of the hydraulic rod 18 is provided with an arc-shaped groove, which is more conducive to the hydraulic rod 18 catching the workpiece and preventing the workpiece from falling.

[0043] A push rod 17 is fixedly connected to the first chute 7. The push rod 17 is located at the high point of the first chute 7 and is positioned close to the hydraulic rod 18. During the descent of the hydraulic rod 18, the push rod 17 will press against the workpiece, and as the hydraulic rod 18 continues to descend, the push rod 17 will push the workpiece away from the upper end of the hydraulic rod 18, and the workpiece will roll onto the first chute 7.

[0044] Both sides of the upper end of the baffle 12 are threaded with fixing bolts 11, and the lower ends of the fixing bolts 11 abut against the outer shell 3. If necessary, the baffle 12 can be fixed by rotating the fixing bolts 11 to tightly abut against the outer shell 3.

[0045] Support plates 6 are fixedly connected to both sides of the lower end of the outer casing 3. These plates are used to support the outer casing 3.

[0046] The outer casing 3 has a discharge port 8 on its side wall. One end of the first chute 7 is assumed to be on the discharge port 8, and the discharge port 8 is oriented towards the quenching tank 2. This allows the heated workpiece to smoothly roll from the first chute 7 into the quenching tank 2, achieving rapid quenching.

[0047] Working principle: During operation, the spherical workpiece is placed on the second chute 9, the servo motor 14 is started, and the movement of the baffle 12 is controlled through the gear 15 and rack 13, so that the workpiece falls from the discharge port 16 in sequence, and the hydraulic rod 18 is lifted to the discharge port 16. The falling workpiece lands on the upper end of the hydraulic rod 18, and the hydraulic cylinder 10 is activated again. The workpiece descends with the hydraulic rod 18. When it passes through the coil 4, the workpiece is induction heated. As the workpiece falls, the push rod 17 pushes the workpiece onto the first chute 7. The workpiece rolls on the first chute 7 and passes through the heat exchanger 5 to improve the uniformity of the workpiece surface. Finally, the workpiece passes through the discharge port 8 and enters the quenching tank 2 to achieve quenching treatment.

[0048] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A process for changing the quenching temperature according to the workpiece diameter, characterized in that, Includes the following steps: Step 1: Calculate the diameter of the spherical workpiece; Step 2: First, obtain the time it takes for the workpiece to pass through the high-frequency heating coil. Then, based on the material of the workpiece, obtain the heat generated by the workpiece per unit time per unit current. Combined with the quenching process, calculate the current required for the workpiece to reach the specified quenching depth and quenching temperature. Step 3: After the workpiece is heated for the first time, it is sent into the uniform temperature chamber, and the temperature of the chamber is 50-100°C higher than the quenching temperature, and the time is controlled to be less than 10 seconds. Step 4: Remove the workpiece from the equalization chamber and place it in the quenching liquid for treatment; It also includes process equipment, specifically including a heating device (1) and a quenching tank (2). The quenching tank (2) is placed on one side of the heating device (1). The heating device (1) includes a shell (3). A second chute (9) is inclinedly arranged in the middle of the upper end of the shell (3). A discharge port (16) is arranged at the lower part of the second chute (9). A coil (4) is arranged below the discharge port (16). A first chute (7) is inclinedly arranged inside the shell (3). A heat spreader (5) of electric heating form is fixedly connected in the middle of the first chute (7). One end of the first chute (7) is located directly below the coil (4). A baffle (12) is slidably provided at the material discharge port (16). A rack (13) is fixedly connected to the upper end of the baffle (12). A servo motor (14) with an encoder is fixedly connected to the upper end of the housing (3). A gear (15) is fixedly connected to the output end of the servo motor (14). The gear (15) and the rack (13) are meshed.

2. The process for changing the quenching temperature according to the workpiece diameter according to claim 1, characterized in that: The quenching fluid is a water-soluble quenching medium.

3. The process for changing the quenching temperature according to the workpiece diameter according to claim 1, characterized in that: A hydraulic cylinder (10) is fixedly connected to the lower end of the outer shell (3). A hydraulic rod (18) is extended from the upper end of the hydraulic cylinder (10). The hydraulic rod (18) passes through the first chute (7) upward and is located directly below the coil (4). An arc-shaped groove is provided at the upper end of the hydraulic rod (18).

4. The process for changing the quenching temperature according to the workpiece diameter according to claim 3, characterized in that: A top rod (17) is fixedly connected to the first chute (7). The top rod (17) is located at a high point of the first chute (7) and is set close to the hydraulic rod (18).

5. The process for changing the quenching temperature according to the workpiece diameter according to claim 1, characterized in that: Both sides of the upper end of the baffle (12) are threaded with fixing bolts (11), and the lower end of the fixing bolts (11) abuts against the outer shell (3).

6. The process for changing the quenching temperature according to the workpiece diameter according to claim 1, characterized in that: Support plates (6) are fixedly connected to both sides of the lower end of the outer shell (3).

7. The process for changing the quenching temperature according to the workpiece diameter according to claim 1, characterized in that: The outer shell (3) has a discharge port (8) on its side wall. One end of the first chute (7) is mounted on the discharge port (8), and the discharge port (8) is positioned facing the quenching tank (2).

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