Outer-tooth friction plate induction quenching device and method

Abstract

The application relates to the field of friction plate forming technology, in particular to an outer-tooth friction plate induction quenching tool and method, which comprises a lower die and an upper die, the lower die comprises a first boss and a second boss, the outer diameter of the first boss is smaller than that of the second boss, at least two first grooves are arranged on the first boss, spring sheets are arranged in the first grooves, a second groove is arranged on the upper die, the outer diameter of a friction plate is larger than that of the second boss, and the inner diameter of the friction plate matches the outer diameter of the first boss. The friction plate is placed on the second boss, the position of the friction plate is adjusted through the spring sheets, the upper part of the friction plate is pressed by the upper die, the positioning of the friction plate is accurate, the friction plate is prevented from being warped and deformed during the induction quenching process, the size precision of the friction plate is influenced, the elastic principle of the spring sheets is utilized, the inner hole of the irregular inner circle of the friction plate is supported, and the inner hole and the inner and outer circles are centered.

Description

Technical Field

[0001] This invention relates to the field of friction plate forming technology, specifically to an induction hardening tooling and method for external tooth friction plates. Background Technology

[0002] Friction plates are key components of brakes and clutches in vehicles such as cars, trains, and airplanes, and their performance directly affects the stability of the machine and the safety of personnel.

[0003] Induction hardening can alter the local mechanical properties of friction plates, improving their wear resistance. It has wide applications in automotive manufacturing, construction machinery, and other fields. Induction hardening utilizes an alternating magnetic field to generate an induced current, locally heating the workpiece to the hardening temperature. Therefore, each type of friction plate requires an induction hardening coil. The coil's shape and structure are designed according to the requirements of the hardened area of ​​the friction plate.

[0004] Induction hardening makes parts more prone to deformation during heating. Therefore, most existing surface treatment methods for friction plate teeth use processes such as carburizing, carbonitriding, nitriding, and laser hardening, but these processes are relatively expensive. Summary of the Invention

[0005] This invention addresses the problem that current methods such as carburizing, carbonitriding, nitriding, and laser quenching are costly and therefore not readily applicable. It provides an induction quenching fixture and method for external gear friction plates.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0007] On one hand, this application provides an induction hardening tooling for external tooth friction plates, including a lower die and an upper die. The lower die includes a first boss and a second boss. The outer diameter of the first boss is smaller than that of the second boss. At least two first grooves are provided on the first boss, and a spring plate is located in the first groove. The upper die is provided with a second groove. The outer diameter of the friction plate is larger than that of the second boss, and the inner diameter of the friction plate matches the outer diameter of the first boss.

[0008] Preferably, the outer diameter of the upper die is smaller than the sum of the root circle diameter of the friction plate teeth and 1-3 times the hardened layer depth, and larger than the sum of the inner circle diameter of the friction plate core die and 1-3 times the hardened layer depth. In this way, during induction hardening, the upper die can isolate the friction plate parts that do not need to be induction hardened, and at the same time, the upper die applies force to the friction plate, which also prevents the friction plate from deforming.

[0009] Preferably, the depth of the second groove is not less than the distance between the arc height of the spring sheet and the first groove. This ensures that the pressure on the spring sheet is relatively small after the upper mold descends, preventing the highest point of the spring sheet from failing to contact the friction plate.

[0010] Preferably, the spring sheet is mounted on the thin plate, and at least one end of the spring sheet is not flush with the end face of the thin plate. Baffles are provided at both the upper and lower ends of the first groove. If the spring sheet is placed directly in the first groove, it may pop out under the action of elastic force. To prevent the spring sheet from popping out, baffles are provided on both the upper and lower sides of the first groove, and the spring sheet is mounted on the thin plate, with the upper and lower sides of the thin plate blocked by the baffles.

[0011] Preferably, the lower mold is hollow, and the inner wall of the lower mold is provided with hooks, which can facilitate the movement of the lower mold.

[0012] Preferably, the height of the upper mold is greater than the height of the first boss. The upper mold is also provided with a lifting mechanism, which includes a first bracket, a second bracket, and a lifting ring. The first bracket and the second bracket are arranged crosswise, and the lifting ring is located at the intersection. This ensures that the upper mold can effectively press down on the end face of the friction plate, and also increases the weight of the upper mold, using its own weight to press down the friction plate and prevent the end face from warping during induction hardening.

[0013] Preferably, the lower mold is also provided with a washer, and the inner wall of the washer is provided with a third groove. The depth of the third groove is / to / the arc height of the spring sheet. The washer is mainly used to adjust the position of the friction plate on the spring sheet. The depth of 1 / 2 to 3 / 4 of the arc height of the spring sheet ensures that the spring sheet can have sufficient support force.

[0014] Preferably, the bottom of the outer wall of the washer is provided with an adjustment groove, which facilitates the disassembly of the washer after use.

[0015] Preferably, four first grooves are evenly provided on the circumference of the first boss.

[0016] On the other hand, this application provides an induction hardening method, comprising the following steps:

[0017] Select a suitable washer based on the thickness of the friction pad and place it on the lower mold;

[0018] Then move the friction plate from top to bottom through the first boss, and adjust the friction plate after it is positioned on the washer;

[0019] The upper mold descends and presses down the friction plate;

[0020] Place the sensor outside the friction plate, adjust the distance, and start the sensor to perform induction hardening.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows: By placing the friction plate on the second protrusion and adjusting the position of the friction plate by means of a spring plate, and pressing the friction plate down by means of an upper mold, the present invention achieves accurate positioning of the friction plate and prevents the friction plate from warping and deforming during induction hardening, thus affecting the dimensional accuracy of the friction plate. By utilizing the elastic principle of the spring plate, the inner hole of the irregular inner circle of the friction plate is supported and aligned with the inner and outer circles. Attached Figure Description

[0022] Figure 1 A schematic diagram of the induction hardening fixture for external tooth friction plates provided in this application;

[0023] Figure 2 for Figure 1 A sectional view;

[0024] Figure 3 for Figure 1 Partial schematic diagram;

[0025] Figure 4 This is a schematic diagram of the lower mold structure;

[0026] Figure 5 This is a schematic diagram of the washer structure;

[0027] Figure 6 This is a schematic diagram of the upper mold structure;

[0028] Figure 7 This is a schematic diagram of the structure of the spring sheet and the thin plate;

[0029] Figure 8 This is a displacement contour plot of the spring sheet under maximum pressure.

[0030] The markings in the diagram are: 1-lower mold, 11-first boss, 12-second boss, 13-first groove, 14-baffle, 15-hook, 2-washer, 21-third groove, 22-adjusting groove, 3-upper mold, 31-first bracket, 32-second bracket, 33-lifting ring, 34-second groove, 4-spring plate, 5-thin plate, 6-friction plate, 7-sensor. Detailed Implementation

[0031] The present invention will now be described in detail with reference to the accompanying drawings.

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0033] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", 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 invention 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 invention.

[0034] In the description of this invention, unless otherwise specified and limited, it should be noted that the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to mechanical or electrical connections, or internal connections between two components. They can be direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0035] like Figures 1 to 7 As shown, this application provides an induction hardening fixture for external toothed friction plates, including a lower die 1, an upper die 3, and a washer 2. The lower die 1 includes a first boss 11 and a second boss 12. The outer diameter of the first boss 11 is smaller than that of the second boss 12, and the cross-section of the lower die 1 is T-shaped. The outer diameter of the first boss 11 matches the inner diameter of the triboelectric sensor, ensuring that the friction plate 6 can be easily and smoothly inserted and removed. The outer diameter of the second boss 12 is smaller than that of the friction plate 6, so that it will not affect the induction hardening of the external teeth on the friction plate 6 by the sensor 7.

[0036] When the friction plate 6 enters from the small end face (top) of the lower mold 1, the upper part of the spring plate 4 is under pressure, which can cause the unfixed spring plate 4 to easily fall out of the groove, resulting in installation failure. Therefore, the spring plate 4 is welded to a thin plate 5. When the friction plate 6 is removed from the lower mold 1, the friction plate moves along the spring plate 4, which can cause the spring plate 4 to move upward, and the spring plate 4 can easily fall out of the first groove 13.

[0037] At least two first grooves 13 are provided on the first protrusion 11. The spring sheet 4 is located in the first groove 13. To prevent the spring sheet 4 from popping out, it is welded to a thin plate 5. At least one end of the spring sheet 4 is not flush with the end face of the thin plate 5. Baffles 14 are installed at both the upper and lower ends of the first groove 13. The upper baffle 14 is connected to the top of the first groove 13 and can be bent upwards. The lower baffle 14 is connected to the bottom of the first groove 13 and can be bent outwards, facilitating the replacement of the spring sheet 4. When the thin plate 5 is located in the first groove 13, the baffles 14 are restored, holding the thin plate 5 and the spring sheet 4 in place. This prevents the spring sheet 4 from popping out under the action of elastic force after the friction plate 6 and the upper mold 3 are pressed downwards in contact with the spring sheet 4, and also facilitates the replacement of the spring sheet 4. Figure 4 As shown, four first grooves 13 are uniformly arranged along the circumference of the first boss 11. The widths of the first groove 13, the second groove 34, and the third groove 21 are the same as the width of the thin plate 5.

[0038] The height H between the spring plate 4 and the thin plate 5 under normal conditions is called the arc height. The outer diameter of the friction plate 6 is greater than the outer diameter of the second boss 12. The outer diameter of the second boss 12 must be smaller than the diameter of the tooth root circle. The arc height is required to ensure that the spring plate 4 is subjected to maximum pressure, such as... Figure 8 The spring plate 4 is completely within the slot, ensuring that the friction plate can smoothly pass through the outer circle of the small end face, and also ensuring that the friction plate is supported when the inner circle of the friction plate is at its maximum size. This achieves support for the inner hole of the friction plate 6 with its irregular inner circle and alignment with the inner and outer circles, preventing uneven distance between the friction plate 6 and the sensor 7, which would lead to different depths of the hardened layer in the teeth, and also preventing accidental collisions from external forces that would cause the center of the friction plate 6 to deviate from the center of the sensor 7.

[0039] The main function of the lower mold 1 is to fix the friction plate 6, so it does not need to be too heavy. In order to reduce the weight of the lower mold 1, the lower mold 1 is designed to be hollow. For easy handling, an L-shaped hook 15 is provided on the inner wall of the lower mold 1.

[0040] To ensure that the friction plate 6 is positioned precisely at the arc height of the spring plate 4 after installation, a washer 2 can be installed on the second boss 12 to adjust the height of the friction plate 6 so that, after placement, the friction plate is centered at the arc height of the spring plate 4. A third groove 21 is provided corresponding to the first groove 13, and the depth of the third groove 21 is 1 / 2 to 3 / 4 of the arc height of the spring plate 4. For easy disassembly, two adjusting grooves 22 are provided symmetrically on the bottom of the outer wall of the groove.

[0041] The upper mold 3 is provided with a second groove 34. The main purpose of the upper mold 3 is to apply pressure to the friction plate 6 so that when it is induction hardened, the lower part of the friction plate 6 contacts the second boss 12 and the upper part is pressed by the upper mold 3, thus preventing it from warping and deforming.

[0042] To avoid affecting induction hardening and warping deformation, the outer diameter of the upper die 3 is smaller than the sum of the root circle diameter of the friction plate 6 and 1-3 times the hardened layer depth, and larger than the sum of the inner circle diameter of the friction plate 6 core die and 1-3 times the hardened layer depth. The hardened layer depth refers to the distance from the tooth surface of the friction plate 6 that is hardened inwards. The outer diameter of the upper die 3 can also be such that it covers 1.5 times the hardened layer depth, i.e., the outer diameter of the upper die 3 is equal to the outer diameter of the entire friction plate 6 minus 1.5 times the hardened layer depth. This is to reduce the influence of the induction heating affected area on the powder sintering area. The depth of the second groove 34 is not less than the distance from the arc height of the spring plate 4 to the first groove 13.

[0043] The height of the upper mold 3 is greater than the height of the first boss 11. To ensure that the washer 2 is installed on the second boss 12, the top of the upper mold 3 must be higher than the top of the first boss 11. The upper mold 3 is also equipped with a lifting mechanism, which includes a first bracket 31, a second bracket 32, and a lifting ring 33. The first bracket 31 and the second bracket 32 ​​are arranged crosswise, and the lifting ring 33 is located at the intersection, facilitating automatic lifting by the hoisting mechanism. The installation and disassembly of the entire fixture are relatively simple and uncomplicated, improving labor efficiency.

[0044] This application also provides an induction hardening method. First, select a suitable washer 2 according to the thickness of the friction plate 6. Place the lower mold 1 on the worktable of the inductor 7. Then, pass the washer 2 through the first boss 11 and place it on the second boss 12. Then, lower the inductor 7 so that the inductor 7 is under the washer 2. Then, insert the friction plate 6 into the lower mold 1 and shake the friction plate 6 left and right to prevent the spring plate 4 from getting stuck and not springing up. Then, adjust the distance between the inductor 7 and the tooth tip circle. Then, press down the upper mold 3 and slowly lift the inductor 7 so that the tooth is completely within the induction area. Finally, perform induction hardening.

[0045] The friction plate 6 has the same external structure as the gear, but it is made of a composite material. The outer part of the core mold is made of steel, and the inside of the core mold is filled with powder material. The core mold is usually annealed, the external dimensions are machined, and the surface is plated with copper and tin. It is pressed and sintered together with the powder. Then the external dimensions of the sintered friction plate 6 are machined. Finally, the tooth surface of the core mold is induction hardened and tempered.

[0046] The frequency of sensor 7 can be high frequency, medium frequency, or low frequency. The frequency selection is mainly determined by the hardening layer depth of the tooth surface. The higher the frequency, the shallower the hardening layer depth. The formula for the hardening layer depth and the device current frequency f is shown in formula (1):

[0047]

[0048] In the formula: f represents the frequency in Hz, and δ represents the hardened layer depth in mm.

[0049] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A kind of outer tooth class friction plate induction quenching tooling, it is characterized in that, The device comprises a lower die (1) and an upper die (3), the lower die (1) comprises a first boss (11) and a second boss (12), the outer diameter of the first boss (11) is smaller than that of the second boss (12), at least two first grooves (13) are arranged on the first boss (11), and a spring sheet (4) is arranged in the first groove (13), the upper die (3) is provided with a second groove (34), the outer diameter of a friction sheet (6) is larger than that of the second boss (12), the inner diameter of the friction sheet (6) matches the outer diameter of the first boss (11), and an inductor (7) is further arranged.

2. The outer toothed friction plate induction quenching tooling of claim 1, wherein, The outer diameter of the upper die (3) is smaller than the sum of the dedendum diameter of the friction sheet (6) and 1-3 times the hardened layer depth, and is larger than the sum of the inner diameter of the core die of the friction sheet (6) and 1-3 times the hardened layer depth.

3. The outer toothed friction plate induction quenching tooling of claim 1, wherein, The depth of the second groove (34) is not less than the distance between the arc height of the spring sheet (4) and the first groove (13).

4. The outer toothed friction plate induction quenching tooling of claim 1, wherein, The spring sheet (4) is arranged on a thin plate (5), at least one end of the spring sheet (4) is not flush with the end surface of the thin plate (5), and the upper and lower ends of the first groove (13) are provided with baffles (14).

5. The outer toothed friction plate induction quenching tooling of claim 1, wherein, The lower die (1) is hollow, and the inner wall of the lower die (1) is provided with a hook (15).

6. The outer toothed friction plate induction quenching tooling of claim 1, wherein, The height of the upper die (3) is greater than the height of the first boss (11), and the upper die (3) is further provided with a hoisting mechanism, the hoisting mechanism comprises a first support (31), a second support (32) and a lifting ring (33), the first support (31) and the second support (32) are arranged in an intersecting manner, and the lifting ring (33) is arranged at the intersection.

7. The outer toothed friction plate induction quenching tooling of claim 1, wherein, The lower die (1) is further provided with a gasket (2), the inner wall of the gasket (2) is provided with a third groove (21), and the depth of the third groove (21) is 1 / 2-3 / 4 of the arc height of the spring sheet (4).

8. The outer toothed friction plate induction quenching tooling of claim 7, wherein, The outer wall of the gasket (2) is provided with an adjusting groove (22) at the bottom.

9. The outer toothed friction plate induction quenching tooling of claim 1, wherein, Four first grooves (13) are uniformly arranged on the circumference of the first boss (11).

10. A method of induction hardening of an outer toothed friction plate induction hardening tool according to claim 7 or 8, characterized in that, The device comprises the following steps: According to the thickness of the friction sheet, a suitable gasket (2) is selected and placed on the lower die (1); Then the friction sheet (6) is moved from top to bottom through the first boss (11), and the height of the friction sheet (6) is adjusted after the friction sheet (6) is located on the gasket (2); The upper die (3) is lowered to press the friction sheet (6); The inductor (7) is placed outside the friction sheet (6), the distance is adjusted, and the inductor (7) is started to induct quenching.

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