Fixture for reducing high-frequency quenching cracks of powder metallurgy component

Abstract

The utility model discloses a fixture for reducing high-frequency quenching cracks of a powder metallurgy part, which comprises a base, an upper baffle plate and a lower baffle plate, the base fixes the metallurgy part, the upper baffle plate is in press fit with the upper surface of the metallurgy part, the lower baffle plate is fixedly assembled on the base, the lower baffle plate is in press fit with the lower surface of the metallurgy part, and the lower baffle plate is fixedly assembled on the base. The lower baffle is provided with a profiling part, the profiling part extends to be close to the sharp corner part of the metallurgical part, the lower baffle is further provided with at least one positioning part, and the metallurgical part is limited and fixed through the positioning parts. According to the utility model, the probability of occurrence of cracks on the tooth surface of a powder metallurgy part product is reduced through the upper baffle plate, and the profile modeling part and the positioning part of the lower baffle plate are matched to ensure that the powder metallurgy part is close to sharp corner parts with complicated structures such as product marking holes and the like, so that the influence of sharp corner effect of high-frequency induction heating is reduced, and the metallurgical part is not easy to crack after being quenched.

Description

Technical Field

[0001] The utility model relates to the technical field of high-frequency induction surface hardening, in particular to a fixture for reducing high-frequency quenching cracks of powder metallurgy parts. Background Art

[0002] During the production of metal powder metallurgy parts, slag inclusions and pores are likely to exist inside. When performing high-frequency quenching, cracks are more likely to appear than other metal parts, especially for products with complex shapes. High-frequency quenching of powder metallurgy parts is to improve surface hardness and wear resistance, thereby increasing service life. When using high-frequency heating, eddy currents are generated near the induction coil. The eddy currents pass through the product, and the skin effect is generated on the product surface, thereby achieving the effect of surface heating.

[0003] For products with complex shapes, due to the "sharp corner effect" in high-frequency induction heating, the temperature rises rapidly within a very short time and overheating occurs. The internal structure at the sharp corner position is coarsened, increasing the risk of crack generation during quenching. In particular, for the high-frequency quenching treatment of the tooth surface of a powder metallurgy sprocket, in addition to cracks being easily generated on the tooth surface, due to the presence of marking holes near the tooth surface and the requirement of a certain surface quenching hardening layer depth for the sprocket, cracks are easily generated at the edge of the marking holes during quenching, resulting in defects. Summary of the Utility Model

[0004] In order to overcome the above-mentioned shortcomings of the prior art, the purpose of the utility model is to provide a fixture for reducing high-frequency quenching cracks of powder metallurgy parts, reducing the sharp corner effect during high-frequency induction heating of powder metallurgy parts and reducing the occurrence of cracks after quenching.

[0005] The technical solution adopted by the utility model to solve its technical problems is: a fixture for reducing high-frequency quenching cracks of powder metallurgy parts, including a base, an upper baffle and a lower baffle. The base fixes the metallurgy part, the upper baffle is tightly pressed and attached to the upper surface of the metallurgy part, the lower baffle is fixedly assembled on the base, the lower baffle is tightly pressed and attached to the lower surface of the metallurgy part, the lower baffle is provided with a profiling part, the profiling part extends close to the sharp corner part of the metallurgy part, and the lower baffle is further provided with at least one positioning part, and the positioning part limits and fixes the metallurgy part.

[0006] As a further improvement of the utility model: it further includes a first driving member, the first driving member is connected to the upper baffle, and the first driving member drives the upper baffle to perform a linear motion.

[0007] As a further improvement of the utility model: it further includes a second driving member, the second driving member is connected to the lower baffle, and the second driving member drives the lower baffle to rotate.

[0008] As a further improvement of the utility model: a positioning groove is formed on the upper baffle, a fixing block is provided on the base, and the fixing block passes through the metallurgy part and is embedded in the positioning groove.

[0009] As a further improvement of the present utility model: a rotating shaft is connected to the output end of the second driving member, and the base is fixedly installed on the rotating shaft.

[0010] As a further improvement of the present utility model: it further includes a fixed seat and a lifting table. The second driving member is assembled on the lifting table. A third driving member is provided on the fixed seat. The third driving member is connected to the lifting table, and the third driving member drives the lifting table to perform linear motion.

[0011] As a further improvement of the present utility model: it further includes a guide rail. The guide rail is arranged between the lifting table and the fixed seat, and the guide rail follows the lifting table to perform linear motion.

[0012] As a further improvement of the present utility model: the upper baffle is circular in shape, and the outer edge of the upper baffle extends close to the sharp corner part of the metallurgical part.

[0013] As a further improvement of the present utility model: a positioning part is formed by protruding on the lower baffle, and the positioning part is embedded in the card slot of the metallurgical part.

[0014] As a further improvement of the present utility model: a quenching base is assembled between the upper baffle and the lower baffle. An induction coil is installed on one side of the quenching base close to the upper baffle. A placement groove for the metallurgical part to be embedded is provided on the quenching base.

[0015] Compared with the prior art, the beneficial effects of the present utility model are:

[0016] The present utility model designs an upper baffle and a lower baffle. The upper baffle is tightly pressed and fitted with the upper surface of the metallurgical part, and the lower baffle is tightly pressed and fitted with the lower surface of the metallurgical part, so as to limit and fix the metallurgical part between the upper and lower baffles. The provided upper baffle can reduce the depth of the surface quenching hardening layer of the powder metallurgy part product, and can reduce the speed of temperature spreading inward within the time when the product surface is inductively heated to a certain temperature, reducing the occurrence probability of tooth surface cracks in the powder metallurgy part product. By designing a profiling part on the lower baffle close to the sharp corner part of the metallurgical part, and also limiting and fixing the metallurgical part through the positioning part, the influence of the "sharp corner effect" of high-frequency induction heating is reduced, so that the temperature at the sharp corner position will not be overheated to cause coarse grains, and cracks are not likely to appear after quenching. Description of the Drawings

[0017] Figure 1 It is a schematic structural diagram of a fixture for reducing high-frequency quenching cracks of powder metallurgy parts of the present utility model.

[0018] Figure 2 It is a schematic structural diagram of a fixture for reducing high-frequency quenching cracks of powder metallurgy parts of the present utility model.

[0019] Figure 3This is a top view of a fixture for reducing high-frequency quenching cracks in powder metallurgy parts according to the present utility model.

[0020] Figure 4 This is a state diagram during high-frequency quenching heating of a fixture for reducing high-frequency quenching cracks in powder metallurgy parts according to the present utility model.

[0021] Reference numerals:

[0022] 1. Upper baffle, 101. Positioning groove, 2. Lower baffle, 21. Profiled part, 22. Positioning part, 3. Base, 31. Fixed block, 4. First driving member, 5. Second driving member, 6. Rotating shaft, 7. Fixed seat, 8. Lifting table, 9. Third driving member, 10. Guide rail, 11. Quenching base, 111. Placing groove, 12. Induction coil, 13. Sprocket, 131. Marking hole. Detailed implementation manners

[0023] To make the objectives, technical solutions and advantages of the present utility model clearer, the technical solutions of the present utility model will be clearly and completely described below in conjunction with specific embodiments of the present utility model and the corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0024] To solve the technical problems in the prior art, the present utility model will be further described below in conjunction with the accompanying drawings and embodiments:

[0025] As Figures 1 to 4 shown, an embodiment of the present utility model discloses a fixture for reducing high-frequency quenching cracks in powder metallurgy parts, including a base 3, an upper baffle 1 and a lower baffle 2. The base 3 is used to fix the metallurgy part. The upper baffle 1 is tightly pressed and attached to the upper surface of the metallurgy part. The lower baffle 2 is fixedly assembled on the base 3. The lower baffle 2 is tightly pressed and attached to the lower surface of the metallurgy part. The lower baffle 2 is provided with a profiled part 21, and the profiled part 21 extends close to or near the sharp corner part of the metallurgy part. The lower baffle 2 is further provided with at least one positioning part 22, and the positioning part 22 limits and fixes the metallurgy part.

[0026] In this embodiment, the base 3 is arranged below the metallurgy part. The lower baffle 2 is fixedly assembled on the base 3. The lower block is tightly pressed and attached to the lower surface of the metallurgy part. At the same time, the lower baffle 2 is designed with a profiled part 21 and at least one positioning part 22. The positioning part 22 usually cooperates with a clamping groove on the metallurgy part product. The profiled part 21 is close to the sharp corner part of complex structures such as the marking hole 131 on the metallurgy part product, reducing the influence of the "sharp corner effect" of high-frequency induction heating, so that the temperature at the sharp corner position will not be overheated to cause coarse grains, and cracks are not likely to appear after quenching.

[0027] The embodiment also positions the metallurgical part product between the upper baffle 1 and the lower baffle 2 by setting the upper baffle 1, pressing and fitting the upper baffle 1 tightly against the upper surface of the product. During the time when the surface of the product is inductively heated to a certain temperature, it can reduce the speed of temperature spreading inward. The temperature spreading speed, the temperature difference between the outermost surface and the core, plus the density of eddy current passing through the metallurgical part, reduce the depth of the surface quenching and hardening layer of the powder metallurgy part product, reduce the density of eddy current passing through the metallurgical part, and reduce the occurrence probability of tooth surface cracks in the powder metallurgy part product.

[0028] In specific applications, for the surface high-frequency quenching of the tooth surface of the powder metallurgy sprocket 13, to solve the problem that its tooth surface is prone to cracks, the upper baffle 1 is used to press tightly on the upper surface of the sprocket 13 to reduce the cracks on the tooth surface. Before the surface of the product tooth surface is heated to a temperature, it reduces the eddy current passing through the product, reduces the further penetration of the surface quenching and hardening layer depth of the product (the deeper the surface quenching and hardening layer depth, the greater the probability of cracks in the product), and the depth of the surface quenching and hardening layer of the product is required to be more than 0.5 mm.

[0029] Also, aiming at the problem that cracks are prone to occur when quenching the tooth surface of the sprocket 13 with the marking hole 131, the profiling part 21 of the lower baffle 2 approaches the part of the marking hole 131, which is also the above-mentioned sharp corner part. When the product is high-frequency heated, it reduces the influence of the "sharp corner effect", thereby reducing the probability of cracks appearing on the edge of the marking hole 131. The profiling part 21 of the lower baffle 2 cooperates with the positioning part 22 to ensure that the profiling part 21 can cover and approach the sharp corner parts of complex structures such as the marking hole 131.

[0030] In some embodiments, it further includes a first driving member 4. The first driving member 4 is connected to the upper baffle 1, and the first driving member 4 drives the upper baffle 1 to perform a linear motion.

[0031] The first driving member 4 can adopt a telescopic cylinder. The piston rod of the cylinder is connected to the upper baffle 1. The piston rod of the cylinder extends or retracts to realize the linear motion of the upper baffle 1, so that the upper baffle 1 moves closer to or away from the upper surface of the metallurgical part product, thereby realizing the action of pressing or loosening the metallurgical part by the upper baffle 1.

[0032] In some embodiments, it further includes a second driving member 5. The second driving member 5 is connected to the lower baffle 2, and the second driving member 5 drives the lower baffle 2 to rotate.

[0033] In a specific example, the output end of the second driving member 5 is connected to a rotating shaft 6, and the base 3 is fixedly installed on the rotating shaft 6. The product is fixed on the base 3. The base 3 can be sleeved on the outer periphery of the rotating shaft 6, and the lower baffle 2 is arranged between the product and the base.

[0034] The second driving member 5 can be a rotary motor. The output end of the rotary motor is equipped with a rotating shaft 6, and the lower baffle 2 is installed on the rotating shaft 6. The lower baffle 2 is driven by the rotary motor to make a rotational movement. The metallurgical part product is placed at the lower baffle 2 on the base 3. During quenching, the metallurgical part product is placed in the quenching base 11. The first driving member 4 is controlled to drive the upper baffle 1 to move towards the surface of the product, and the upper baffle 1 fits against the surface of the product.

[0035] In some embodiments, it further includes a fixed seat 7 and a lifting platform 8. The second driving member 5 is assembled on the lifting platform. A third driving member 9 is provided on the fixed seat 7. The third driving member 9 is connected to the lifting platform 8, and the third driving member 9 drives the lifting platform 8 to make a linear movement.

[0036] An installation hole is formed on the lifting platform 8. The rotating shaft 6 passes through the installation hole and extends out of the upper end of the lifting platform 8 to be fixedly connected to the base 3 and the lower baffle 2. Generally, a bearing is provided in the installation hole, and the rotating shaft 6 is assembled with the bearing. The lower end of the rotating shaft 6 is connected to the second driving member 5 through a coupling. The second driving member 5 is fixedly installed on the lifting platform 8. The third driving member 9 drives the lifting platform 8 and the second driving member 5 as a whole to make a lifting movement. The third driving member 9 can be a telescopic cylinder.

[0037] Furthermore, it further includes a guide rail 10. The guide rail 10 is arranged between the lifting platform 8 and the fixed seat 7, and the guide rail 10 follows the lifting platform 8 to make a linear movement. Four guide rails 10 can be installed between the fixed seat 7 and the lifting platform 8 to ensure the stability and reliability when the third driving member 9 drives the lifting platform 8 to make a linear movement.

[0038] In some embodiments, a positioning groove 101 is formed on the upper baffle 1, and a fixing block 31 is provided on the base 3. The fixing block 31 passes through the metallurgical part and is embedded in the positioning groove 101. Specifically, for the sprocket 13 metallurgical part, a through hole is formed in the middle of the sprocket 13 product. The base 3 is fixed on the rotating shaft 6, and the fixing block 31 is arranged on the base 3. The fixing block 31 is clamped into the through hole of the sprocket 13 product. At this time, the lower baffle 2 fits against the lower surface of the sprocket 13 product. The first driving member 4 drives the upper baffle 1 to move close to the upper surface of the sprocket 13 product. After the fixing block 31 on the base 3 passes through the through hole of the sprocket 13 product, it is clamped into the positioning groove 101 of the upper baffle edge. Thus, the fixing and limiting of the upper baffle 1 and the lower baffle 2 on the sprocket 13 product are completed, and the quenching work starts.

[0039] Preferably, the base 3 can be a stepped boss, provided with a first boss and a second boss. The first boss and the second boss are integrally formed. A limiting hole is formed at the bottom of the first boss, and the limiting hole is sleeved on one end of the rotating shaft 6. The second boss is inserted into the through hole of the sprocket. The diameter of the second boss is specifically designed according to the through hole of the sprocket.

[0040] Furthermore, a positioning portion 22 is formed by protruding on the lower baffle 2, and the positioning portion 22 is embedded in the card slot of the metallurgical part. The product of the metallurgical part sprocket 13 has a card slot, and the positioning portion 22 of the lower baffle 2 can be formed into a convex shape to form a positioning block. The convex positioning portion 22 / positioning block cooperates with the groove on the product to further fix and limit the sprocket 13 product. The sprocket 13 product fits against the lower baffle 2 and is in a horizontal state, ensuring that the profiling portion 21 is close to the marking hole 131 on the tooth surface of the sprocket 13 product. The sharp corner part also needs to be heated. The profiling portion 31 is close to or near the edge of the marking hole, avoiding the over-concentration of the density of the eddy current on the sharp corner part, which may cause the temperature of the sharp corner part to be overheated.

[0041] In addition, the shape, size, quantity, etc. of the positioning portion 22 can be specifically adjusted according to the characteristics, structure, and grooves of other metallurgical part products.

[0042] Furthermore, the upper baffle 1 is circular in shape, and the outer edge of the upper baffle 1 extends to cover the sharp corner part of the metallurgical part.

[0043] In some embodiments, a quenching base 11 is assembled between the upper baffle 1 and the lower baffle 2. An induction coil 12 is installed on one side of the quenching base 11 close to the upper baffle 1, and a placement groove 111 for accommodating the embedding of the metallurgical part is provided on the quenching base 11.

[0044] In addition, for the sprocket 13 product, the placement groove 111 is designed to be circular and is adapted to the outer contour of the sprocket 13 product. After the third driving member 9 drives the lifting table 8 to rise in place, the first driving member 4 drives the upper baffle 1 to descend, and the fixing block 31 of the base 3 is inserted into the positioning groove 101 of the upper baffle 1, and the upper baffle 1 fits against the product. When the product is not placed in place, the groove of the product fails to be placed on the positioning portion 22 of the lower baffle 2, resulting in the product not being in a horizontal state and unable to fit against the lower baffle 2. When the upper baffle 1 descends to press the product, it cannot be pressed in place. At this time, the device detects that the cylinder fails to extend and retract in place and generates an alarm prompt, and the high-frequency quenching operation of the device stops.

[0045] The main functions of the present utility model:

[0046] The present utility model reduces the probability of cracks appearing after high-frequency quenching of powder metallurgy part products by setting an upper baffle and a lower baffle, saves production costs, and improves work efficiency. The positioning portion is provided on the lower baffle to cooperate with the card slot of the product, ensuring that the profiling portion can approach the sharp corner parts of complex structures such as the product marking hole, reducing the influence of the "sharp corner effect" of high-frequency induction heating, so that the temperature at the sharp corner position will not be overheated to cause coarse grains, and cracks are likely to appear after quenching. Setting the upper baffle reduces the depth of the surface quenching hardened layer of the powder metallurgy part product and reduces the probability of cracks appearing on the tooth surface of the powder metallurgy part product.

[0047] In summary, after reading the documents of the present utility model, those of ordinary skill in the art can make various other corresponding transformation schemes without creative mental labor according to the technical solutions and technical concepts of the present utility model, and all of them fall within the scope protected by the present utility model.

Claims

1. A fixture for reducing high-frequency quenching cracks of powder metallurgy parts, characterized in that, It includes a base, an upper baffle and a lower baffle. The base fixes the metallurgical part. The upper baffle is tightly pressed and fitted with the upper surface of the metallurgical part. The lower baffle is fixedly assembled on the base. The lower baffle is tightly pressed and fitted with the lower surface of the metallurgical part. The lower baffle is provided with a profiling part which extends close to the sharp corner part of the metallurgical part. The lower baffle is also provided with at least one positioning part which limits and fixes the metallurgical part.

2. The fixture for reducing high-frequency quenching cracks of powder metallurgy parts according to claim 1, characterized in that, It further includes a first driving part which is connected with the upper baffle and drives the upper baffle to move linearly.

3. A fixture for reducing high-frequency quenching cracks of powder metallurgy parts according to claim 1 or 2, characterized in that, It further includes a second driving part which is connected with the lower baffle and drives the lower baffle to rotate.

4. A fixture for reducing high-frequency quenching cracks of powder metallurgy parts according to claim 3, characterized in that, A positioning groove is formed on the upper baffle, and a fixing block is arranged on the base. The fixing block passes through the metallurgical part and is embedded in the positioning groove.

5. A fixture for reducing high-frequency quenching cracks of powder metallurgy parts according to claim 4, characterized in that, The output end of the second driving part is connected with a rotating shaft, and the base is fixedly installed on the rotating shaft.

6. A fixture for reducing high-frequency quenching cracks of powder metallurgy parts according to claim 5, characterized in that, It further includes a fixing seat and a lifting table. The second driving part is assembled on the lifting table. A third driving part is arranged on the fixing seat. The third driving part is connected with the lifting table and drives the lifting table to move linearly.

7. A fixture for reducing high-frequency quenching cracks of powder metallurgy parts according to claim 6, characterized in that, It further includes a guide rail which is arranged between the lifting table and the fixing seat and moves linearly following the lifting table.

8. A fixture for reducing high-frequency quenching cracks of powder metallurgy parts according to any one of claims 1, 2, 4, 6, and 7, characterized in that, The upper baffle is circular in shape, and the outer edge of the upper baffle extends close to the sharp corner part of the metallurgical part.

9. A fixture for reducing high-frequency quenching cracks in powder metallurgy parts according to claim 8, characterized in that, The positioning part is formed by a protrusion on the lower baffle, and the positioning part is embedded in the clamping groove of the metallurgical part.

10. A fixture for reducing high-frequency quenching cracks of powder metallurgy parts according to claim 9, characterized in that, A quenching base is assembled between the upper baffle and the lower baffle. An induction coil is installed on one side of the quenching base close to the upper baffle. A placement groove for accommodating the embedding of the metallurgical part is arranged on the quenching base.

Images