A quenching fixture

Abstract

This utility model provides a quenching fixture, including a power supply transformer, a connecting rod, an inductor, and a cooling spray water box. The quenching channel of the workpiece to be quenched has a concave arc shape. The inductor is configured as an arc-shaped strip structure matching the shape of the quenching channel. The inductor is arranged parallel to the quenching channel. One straight side of the inductor is connected to the power supply transformer through the connecting rod, and one arc-shaped side of the inductor is connected to the cooling spray water box. The cooling spray water box is configured as an arc-shaped strip structure with the same shape as the inductor. The cooling spray water box is arranged parallel to the quenching channel. The workpiece to be quenched is set vertically and rotates 360° during operation. The gap between the inductor and the quenching channel is 2mm. This fixture can be used to quench stacker-reclaimer bearings and stacker-reclaimer bearing ball changing fixtures.

Description

Technical Field

[0001] This utility model belongs to the field of bearing quenching technology, and in particular, a quenching tool. Background Technology

[0002] Our company undertook the surface hardening of a slewing bearing for a mining stacker-reclaimer with a slewing center diameter of Ø3100mm. This product has large rolling elements (φ110mm) and high technical requirements (70° hardening zone, depth over 5mm). The material is 51CrV4, which has a higher risk of heat treatment cracking. This material is generally used abroad, and there is no precedent for its use in China. Currently, heat treatment methods for this type of bearing suffer from insufficient hardened layer depth and insufficient hardness, and there is zero experience with surface hardening of 51CrV4 material, with no reference cases. Therefore, it is necessary to design a dedicated inductor and heat treatment parameters to perform surface hardening on this batch of products.

[0003] Our company also undertook the surface hardening of two ball-changing fixtures for slewing support bearings used in mining stacker-reclaimers. These fixtures are 320mm long and have built-in contoured channels, with one side having a thinner wall and sharp corners. Currently, machining this type of fixture leads to cracking on the thinner side and uneven hardening. Therefore, a dedicated clamping fixture needs to be designed for proper operation on the hardening equipment, along with the design of the inductor heating zone and thermal processing parameters, to perform surface hardening on this batch of products. Utility Model Content

[0004] In view of the above problems, the purpose of this application is to provide a quenching fixture that enables quenching of stacker-reclaimer bearings and stacker-reclaimer bearing ball changing fixtures.

[0005] To achieve some or all of the above objectives or other objectives, this application provides the following technical solution: a quenching fixture, including a power supply transformer, a connecting rod, an inductor, and a cooling spray water box; the cross-section of the quenching channel of the workpiece to be quenched is concave arc-shaped; the inductor is configured as an arc-shaped strip structure matching the shape of the quenching channel; the inductor is arranged parallel to the quenching channel; one straight side of the inductor is connected to the power supply transformer through the connecting rod; one arc-shaped side of the inductor is connected to the cooling spray water box; the cooling spray water box is configured as an arc-shaped strip structure with the same shape as the inductor; the cooling spray water box is arranged parallel to the quenching channel; the workpiece to be quenched is vertically arranged; the workpiece to be quenched rotates 360° during operation.

[0006] Furthermore, the power supply transformer is fixedly connected to the equipment, and the connecting rod and the sensor are hinged together; the gap between the sensor and the quenching channel is 2mm.

[0007] Furthermore, the sensor and the cooling spray water box are integrated into one unit.

[0008] Furthermore, it also includes rotating rollers; the rotating rollers are fixedly installed on the vertical equipment, and there are three rotating rollers, namely roller number one, roller number two and roller number three. The three rotating rollers are arranged in a triangle to drive the workpiece to be quenched to rotate 360°.

[0009] Furthermore, the workpiece to be quenched is a stacker-reclaimer bearing; the stacker-reclaimer bearing is annular, the quenching channel cross-section of the stacker-reclaimer bearing is semi-circular, and the cross-section of the inductor is semi-circular and matches the stacker-reclaimer bearing; the first roller contacts the top of the inner diameter of the stacker-reclaimer bearing, and the second and third rollers respectively contact the lower part of the outer diameter of the stacker-reclaimer bearing; the stacker-reclaimer bearing achieves 360° rotation through three rotating rollers, and the three rotating rollers together define the relative position of the stacker-reclaimer bearing.

[0010] Furthermore, the quenching groove of the stacker-reclaimer bearing adopts an induction heating quenching method with a heating current of 221A and a voltage of 308V. During the quenching process, the stacker-reclaimer bearing is uniformly heated by rotating 360°, with a moving speed of 170mm / min. The quenching medium uses German Derunbao water-soluble quenching agent with a medium temperature of 25-40℃, a medium concentration of 12-17%, and a cooling spray water box flow rate of 49L / min. The cooling delay is 30s. After quenching, the tempering furnace is heated to 175℃ and held at that temperature. Then, two tempering processes are performed: the first is a heat treatment followed by a 16-hour holding time, and the second is a hardening of the raceway followed by a 6-hour holding time.

[0011] Furthermore, the workpiece to be quenched is a stacker-reclaimer bearing ball changing fixture, and the quenching groove cross-section of the stacker-reclaimer bearing ball changing fixture is arc-shaped; it also includes a fixing fixture; the fixing fixture is annular, and the fixing fixture is fixedly connected to the side of the stacker-reclaimer bearing ball changing fixture away from the quenching groove; the first roller contacts the top of the inner diameter of the ring of the fixing fixture, and the second and third rollers respectively contact the lower part of the outer diameter of the ring of the fixing fixture; the fixing fixture achieves 360° rotation through the three rotating rollers, and the three rotating rollers together define the relative position of the fixing fixture.

[0012] Furthermore, the stacker-reclaimer bearing ball changing fixture is provided with a boss, which is located near the quenching groove of the stacker-reclaimer bearing ball changing fixture and is arranged parallel to the quenching groove of the stacker-reclaimer bearing ball changing fixture; the connecting rod is provided with a recess that matches the boss.

[0013] Furthermore, the quenching groove of the stacker-reclaimer bearing ball changing tooling adopts an induction heating quenching method with a heating current of 221A and a voltage of 308V. During the quenching process, the stacker-reclaimer bearing ball changing tooling rotates 360° for uniform heating, with a moving speed of 100mm / min. The quenching medium uses German Derunbao water-soluble quenching agent with a medium temperature of 25-40℃, a medium concentration of 12-17%, and a cooling spray water box flow rate of 49L / min. The cooling delay is 30s. After quenching, the tempering furnace is heated to 175℃ and held at that temperature. Then, two tempering processes are performed: the first is a heat treatment followed by a 16-hour holding time, and the second is a hardening of the raceway followed by a 6-hour holding time.

[0014] Compared with existing technologies, the advantages of this invention are as follows: The inductor is designed according to the shape and size of the quenching channel. The effective heating zone is made of tightly arranged 0.2mm thick silicon steel sheets, forming a closed magnetic field loop composed of preheating and heating parts. This product ensures that the channel, centered on the bottom, requires quenching hardening within a 70° range. When designing the inductor, key considerations such as temperature distribution, risk points, and technical requirements must be taken into account. The silicon steel sheets should not be completely filled; no silicon steel sheets are allowed within 20mm of the outer edge of the channel. This inductor design ensures the technical requirements of the hardened area while preventing quenching cracks at the outer edge of the channel.

[0015] The inductor is designed based on the groove shape and dimensions. Due to the thinner wall and sharp corner on one side of the tooling, this area experiences extremely high stress during quenching, making it highly susceptible to quenching cracks due to the sharp corner effect. Therefore, the heating zone of the inductor in this area needs to have a reduced amount of silicon steel sheet. Considering the good thermal conductivity of the weak area, silicon steel sheets are only installed on the thicker side of the tooling wall. During heating, the temperature will be conducted to the main contact area of ​​the rolling element, thus achieving hardening. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of Example 1; Figure 2 This is a partially enlarged schematic diagram of Example 1; Figure 3 This is a schematic diagram of the power supply transformer, connecting rod, sensor, and cooling spray water box in Example 1. Figure 4 This is a cross-sectional view of the stacker-reclaimer bearing of Example 1; Figure 5 This is a cross-sectional schematic diagram of the sensor and stacker-reclaimer bearing in Example 1; Figure 6 This is a schematic diagram of the structure of Example 2; Figure 7 This is a partially enlarged schematic diagram of Example 2; In the diagram: 1. Power supply transformer; 2. Connecting rod; 201. Recess; 3. Sensor; 4. Cooling spray water box; 5. Roller No. 1; 6. Roller No. 2; 7. Roller No. 3; 8. Stacker-reclaimer bearing; 801. Quenching groove of stacker-reclaimer bearing; 9. Stacker-reclaimer bearing ball changing fixture; 901. Quenching groove of stacker-reclaimer bearing ball changing fixture; 902. Boss; 10. Fixing jig. Detailed Implementation

[0017] To make the structure and function of this utility model clearer, the technical solutions in the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Example 1

[0018] See appendix Figure 1-5 A quenching fixture includes a power supply transformer 1, a connecting rod 2, an inductor 3, and a cooling spray water box 4. The quenching channel of the workpiece to be quenched has a concave arc shape. The inductor 3 is configured as an arc-shaped strip structure matching the shape of the quenching channel. The inductor 3 is arranged parallel to the quenching channel. One straight side of the inductor 3 is connected to the power supply transformer 1 through the connecting rod 2. One arc-shaped side of the inductor 3 is connected to the cooling spray water box 4. The cooling spray water box 4 is configured as an arc-shaped strip structure with the same shape as the inductor 3. The cooling spray water box 4 is arranged parallel to the quenching channel. The workpiece to be quenched is vertically arranged and rotates 360° during operation.

[0019] The power supply transformer is fixedly connected to the equipment. The connecting rod 2 and the sensor 3 are hinged together, and the gap between the sensor 3 and the quenching channel can be adjusted. The gap between the sensor 3 and the quenching channel is 2mm.

[0020] The gap between the sensor 3 and the quenching channel is 2mm.

[0021] The sensor 3 and the cooling spray water box 4 are integrated into one unit.

[0022] It also includes rotating rollers; the rotating rollers are fixedly installed on the vertical equipment. There are three rotating rollers, namely roller 5, roller 6, and roller 7. The three rotating rollers are arranged in a triangle to drive the workpiece to be quenched to rotate 360°.

[0023] The workpiece to be quenched is a stacker-reclaimer bearing 8; the stacker-reclaimer bearing 8 is annular, the quenching channel 801 of the stacker-reclaimer bearing has a semi-circular cross-section, and the cross-section of the inductor 3 is a semi-circular shape matching the stacker-reclaimer bearing 8; the first roller 5 contacts the top of the inner diameter of the stacker-reclaimer bearing 8, the second roller 6 and the third roller 7 respectively contact the lower part of the outer diameter of the stacker-reclaimer bearing 8, and the stacker-reclaimer bearing 8 achieves 360° rotation through the three rotating rollers, and the three rotating rollers together define the relative position of the stacker-reclaimer bearing 8.

[0024] Three rotating rollers are fixedly installed on the vertical equipment in a triangular arrangement. Roller 5 is located at the top of the inner diameter of the stacker-reclaimer bearing 8, while rollers 6 and 7 are located at the bottom of the outer diameter of the stacker-reclaimer bearing 8 to provide support.

[0025] The quenching groove 801 of the stacker-reclaimer bearing adopts the quenching method of electric heating by induction 3, with a heating current of 221A and a voltage of 308V; the stacker-reclaimer bearing 8 is uniformly heated by 360° rotation during quenching, with a moving speed of 170mm / min; the quenching medium is German Derunbao water-soluble quenching agent, with a medium temperature of 25-40℃, a medium concentration of 12-17%, and a cooling spray water box 4 flow rate of 49L / min; the cooling delay is 30s; after quenching, the tempering furnace is heated to 175℃ and held at that temperature; then it is tempered twice, the first time after heat treatment and held at that temperature for 16h, and the second time after hardening the raceway and then holding at that temperature for 6h.

[0026] Process parameters: (1) The product is quenched by induction heating. The quenching equipment number is 097-007. The heating current is set to 221A and the voltage is 308V according to the process test.

[0027] (2) Since the product is a sensor surface heating and quenching method, according to the skin effect, current needs to be concentrated on the contact surface between the sensor and the workpiece. The heating frequency can affect the surface current density, and thus affect the surface temperature. 2.6KHz is the data obtained from the process test.

[0028] (3) The workpiece needs to be rotated during the heating process to achieve uniform heating in 360° direction. The workpiece needs to have a rotation speed, i.e. the moving speed in the process card. The speed was determined to be 170 mm / min through process experiments.

[0029] (4) The sensor and water box are integrated. 3100-1-007 is its serial number, which is convenient for management and has no special meaning.

[0030] (5) The gap between the inductor and the bottom of the quenching channel is 2mm. This data was obtained through process testing. If it is too close, the raceway may melt due to the magnetic field. If it is too far, the magnetic field will be weak and the hardened layer depth specified in the technical requirements will not be achieved.

[0031] (6) The quenching medium we use is the German BW water-soluble quenching agent, which is commonly used for surface quenching and has excellent properties such as suitable cooling rate.

[0032] (7) During the quenching process, the quenching agent needs to be at a suitable temperature. Too cold will lead to the risk of cracking, and too hot will reduce the surface hardness. 25-40℃ is the suitable temperature.

[0033] (8) The medium concentration is the concentration of quenching agent controlled during the processing. The concentration has an important impact on product quality. The suitable concentration for quenching channel workpieces is 12-17%.

[0034] (9) Cooling delay is the extra time for the quenching agent to be sprayed after the workpiece is quenched, in order to reduce the temperature of the ring and prevent self-tempering that would reduce the hardness.

[0035] (10) Tempering is to heat the product to 175°C in a tempering furnace after quenching and keep it at that temperature. This can significantly reduce the internal stress of the ring. Since the internal stress of this product is large after quenching, it is tempered twice. The first time is to keep it at that temperature for 16 hours after heat treatment, and the second time is to keep it at that temperature for 6 hours after hard turning the raceway.

[0036] Example 2

[0037] See appendix Figure 6-7 A quenching fixture includes a power supply transformer 1, a connecting rod 2, an inductor 3, and a cooling spray water box 4. The quenching channel of the workpiece to be quenched has a concave arc shape. The inductor 3 is configured as an arc-shaped strip structure matching the shape of the quenching channel. The inductor 3 is arranged parallel to the quenching channel. One straight side of the inductor 3 is connected to the power supply transformer 1 through the connecting rod 2. One arc-shaped side of the inductor 3 is connected to the cooling spray water box 4. The cooling spray water box 4 is configured as an arc-shaped strip structure with the same shape as the inductor 3. The cooling spray water box 4 is arranged parallel to the quenching channel. The workpiece to be quenched is vertically arranged and rotates 360° during operation.

[0038] The power supply transformer 1 is fixedly connected to the equipment, and the connecting rod 2 and the sensor 3 are hinged together, which can adjust the gap between the sensor 3 and the quenching channel; the gap between the sensor 3 and the quenching channel is 2mm.

[0039] The sensor 3 and the cooling spray water box 4 are integrated into one unit.

[0040] It also includes rotating rollers; the rotating rollers are fixedly installed on the vertical equipment. There are three rotating rollers, namely roller 5, roller 6, and roller 7. The three rotating rollers are arranged in a triangle to drive the workpiece to be quenched to rotate 360°.

[0041] The workpiece to be quenched is a stacker-reclaimer bearing ball changing fixture 9. The main body of the stacker-reclaimer bearing ball changing fixture 9 is a long strip plate structure with a trapezoidal cross-section. One side of the trapezoidal cross-section has an inwardly recessed continuous groove structure, which is the quenching groove 901 of the stacker-reclaimer bearing ball changing fixture. The surface of the stacker-reclaimer bearing ball changing fixture has a boss 902 extending along the length direction. The boss 902 has a rectangular cross-section and is located close to the quenching groove 901 of the stacker-reclaimer bearing ball changing fixture, and is arranged parallel to the quenching groove 901 of the stacker-reclaimer bearing ball changing fixture. The stacker-reclaimer bearing ball changing fixture is an arc-shaped strip structure with a bending axis, and its bending profile matches the fixed jig 10.

[0042] The quenching groove 901 of the stacker-reclaimer bearing ball changing fixture has an arc-shaped cross-section; it also includes a fixing fixture 10; the fixing fixture 10 is annular, and the fixing fixture 10 is fixedly connected to the side of the stacker-reclaimer bearing ball changing fixture 9 away from the quenching groove; the first roller 5 contacts the top of the inner diameter of the ring of the fixing fixture 10, the second roller 6 and the third roller 7 respectively contact the lower part of the outer diameter of the ring of the fixing fixture 10, and the fixing fixture 10 achieves 360° rotation through the three rotating rollers, and the three rotating rollers together define the relative position of the fixing fixture 10.

[0043] The stacker-reclaimer bearing ball changing fixture 9 is provided with a boss 902, which is located near the quenching groove 901 of the stacker-reclaimer bearing ball changing fixture and is arranged parallel to the quenching groove 901 of the stacker-reclaimer bearing ball changing fixture; the connecting rod 2 is provided with a recess 201 that matches the boss.

[0044] The quenching groove 901 of the stacker-reclaimer bearing ball changing fixture adopts the quenching method of electric heating by induction generator 3, with a heating current of 221A and a voltage of 308V; the stacker-reclaimer bearing ball changing fixture 9 rotates 360° for uniform heating during quenching, with a moving speed of 100mm / min; the quenching medium uses German Derunbao water-soluble quenching agent, with a medium temperature of 25-40℃, a medium concentration of 12-17%, and a cooling spray water box 4 flow rate of 49L / min; the cooling delay is 30s; after quenching, the tempering furnace is heated to 175℃ and held at that temperature; then it undergoes two tempering processes, the first being a heat treatment followed by a 16-hour holding time, and the second being a hard-machined raceway followed by a 6-hour holding time.

[0045] Process parameters: (1) The product is quenched by induction heating. The quenching equipment number is 097-021. The heating current is set to 221A and the voltage is 308V according to the process test.

[0046] (2) Since the product is a sensor surface heating and quenching method, according to the skin effect, current needs to be concentrated on the contact surface between the sensor and the workpiece. The heating frequency can affect the surface current density, and thus affect the surface temperature. 2.6KHz is the data obtained from the process test.

[0047] (3) The workpiece needs to be rotated during the heating process to achieve uniform heating in 360° direction. The workpiece needs to have a rotation speed, i.e. the moving speed in the process card. The speed is determined to be 100 mm / min through process experiments.

[0048] (4) The sensor and water box are integrated. 3100-05-021 is its serial number, which is convenient for management and has no special meaning.

[0049] (5) The gap between the sensor and the bottom of the workpiece groove is 2mm. This data was obtained through process testing. If it is too close, the raceway may melt due to the magnetic field. If it is too far, the magnetic field will be weak and the hardened layer depth specified in the technical requirements will not be achieved.

[0050] (6) The quenching medium we use is the German BW water-soluble quenching agent, which is commonly used for surface quenching and has excellent properties such as suitable cooling rate.

[0051] (7) During the quenching process, the quenching agent needs to be at a suitable temperature. Too cold will lead to the risk of cracking, and too hot will reduce the surface hardness. 25-40℃ is the suitable temperature.

[0052] (8) The medium concentration is the concentration of quenching agent controlled during the processing. The concentration has an important impact on product quality. The suitable concentration for quenching channel workpieces is 12-17%.

[0053] (9) Cooling delay is the extra time for the quenching agent to be sprayed after the workpiece is quenched, in order to reduce the temperature of the ring and prevent self-tempering that would reduce the hardness.

[0054] (10) Tempering is to heat the product to 175°C in a tempering furnace after quenching and keep it at that temperature. This can significantly reduce the internal stress of the ring. Since the internal stress of this product is large after quenching, it is tempered twice. The first time is to keep it at that temperature for 16 hours after heat treatment, and the second time is to keep it at that temperature for 6 hours after hard turning the raceway.

[0055]

[0056] The quenching channel of the ball changing tooling for the stacker reclaimer bearing has a thin wall and sharp corners on one side. Existing processes for quenching this type of tooling can lead to cracks on the thin side and uneven hardening layers. This design incorporates a dedicated clamping tooling to ensure normal operation on the quenching equipment. It also designs the range of the inductor heating zone and the thermal processing parameters to perform surface quenching on this batch of products.

[0057] In the description of this utility model, it should be noted that the terms "upper", "lower", "inner", "outer", "front end", "rear end", "both ends", "one end", "the other end", 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.

[0058] The above-disclosed embodiments are merely preferred embodiments of this application and should not be construed as limiting the scope of this application. Therefore, any equivalent variations made in accordance with the claims of this application shall still fall within the scope of this application.

Claims

1. A quenching fixture, characterized in that: The system includes a power supply transformer, a connecting rod, an inductor, and a cooling spray water box. The cross-section of the quenching channel of the workpiece to be quenched is concave arc-shaped. The inductor is configured as an arc-shaped strip structure that matches the shape of the quenching channel. The inductor is arranged parallel to the quenching channel. One straight side of the inductor is connected to the power supply transformer through the connecting rod, and one arc-shaped side of the inductor is connected to the cooling spray water box. The cooling spray water box is configured as an arc-shaped strip structure with the same shape as the inductor. The cooling spray water box is arranged parallel to the quenching channel.

2. The quenching fixture according to claim 1, characterized in that: The workpiece to be quenched is set vertically and rotates 360° during operation.

3. The quenching fixture according to claim 1, characterized in that: The power supply transformer is fixedly connected to the equipment, and the connecting rod and the sensor are hinged together; the gap between the sensor and the quenching channel is 2mm.

4. A quenching fixture according to claim 1, characterized in that: The sensor and the cooling spray water box are integrated into one unit.

5. A quenching fixture according to claim 1, characterized in that: It also includes rotating rollers; the rotating rollers are fixedly installed on the vertical equipment. There are three rotating rollers, namely roller number one, roller number two, and roller number three. The three rotating rollers are arranged in a triangle to drive the workpiece to be quenched to rotate 360°.

6. A quenching fixture according to claim 5, characterized in that: The workpiece to be quenched is a stacker-reclaimer bearing; the stacker-reclaimer bearing is annular, and the quenching channel of the stacker-reclaimer bearing has a semi-circular cross-section. The cross-section of the inductor is a semi-circular shape that matches the stacker-reclaimer bearing. The first roller contacts the top of the inner diameter of the stacker-reclaimer bearing's annulus, and the second and third rollers respectively contact the lower part of the outer diameter of the stacker-reclaimer bearing's annulus. The stacker-reclaimer bearing achieves 360° rotation through three rotating rollers, and the three rotating rollers together define the relative position of the stacker-reclaimer bearing.

7. A quenching fixture according to claim 5, characterized in that: The workpiece to be quenched is a stacker-reclaimer bearing ball changing fixture, the quenching groove of which has an arc-shaped cross-section; it also includes a fixing fixture; the fixing fixture is annular, and is fixedly connected to the side of the stacker-reclaimer bearing ball changing fixture away from the quenching groove; the first roller contacts the top of the inner diameter of the ring of the fixing fixture, and the second and third rollers respectively contact the lower part of the outer diameter of the ring of the fixing fixture; the fixing fixture achieves 360° rotation through the three rotating rollers, and the three rotating rollers together define the relative position of the fixing fixture.

8. A quenching fixture according to claim 7, characterized in that: The stacker-reclaimer bearing ball changing fixture is provided with a boss, which is located near the quenching groove of the stacker-reclaimer bearing ball changing fixture and is arranged parallel to the quenching groove of the stacker-reclaimer bearing ball changing fixture; the connecting rod is provided with a recess that matches the boss.

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