The use of the drive shaft flange can strengthen the strength of the drive shaft. In addition, the vibration generated by the flange, the position and the size of the flange can be used to balance the vibration of the piston. During the working process, it needs to bear huge friction force, so the flange end face and the outer circle The surface requires high hardness, wear resistance and service life.
statement of problem
In this paper, an automobile flange shaft is taken as an example to analyze and study the technical requirements and problems in the
quenching process. A special quenching sensor for flange parts and a method for determining the size are proposed.
Flange part structure
The structure of the flange part is shown in Figure 1. During the working process, the outer circular surface and the end surface are subjected to a large friction force, which requires high hardness and wear resistance. Therefore, the outer circular surface and the end surface of the part need to be quenched; The basic dimensions of the quenching area of the part are: outer diameter (φ1) is 62 mm, end surface inner diameter (φ2) is 44 mm, and quenching outer circle height (H) is 24 mm.
2. Technical requirements for parts
In order to improve the hardness and wear resistance of the outer and outer faces of the flange, the design requires that the part be subjected to high-frequency quenching treatment at the step, the outer circular surface, the chamfering and the end surface. The hardness of the quenching zone is required to be 50-55HRC, and the hardened layer depth is 1.0. ~2.0mm, the quenching layer is required to be uniform and continuous; for the hardened area of the end face, since the inner hole of the end face is a spline, in order to avoid the quenching crack of the spline, the radial hardening area of the end face is required to be 4 to 5 mm.
3. Parts induction hardening difficulties
Induction quenching has many advantages such as energy saving and high efficiency, but for the flange parts described herein, the following problems exist in induction hardening:
(1) Sharp angle effect is difficult to avoid
In the induction hardening, the outer edge and the end edge formed by the chamfer between the outer circle and the end face of the flange are prone to sharp corner effects, and the current at the sharp corner is prone to dense, causing overheating or overburning, even A quench crack is generated.
(2) The sensing distance is difficult to control
In the actual induction quenching, the sensing distance of the inclined surface formed by the chamfer between the outer circle and the end surface of the flange is not easy to control, affecting the quenching effect at the chamfer, and affecting the quenching uniformity of the quenching region.
Structural design of quenching sensor
Technical solution
The special quenching sensor of the flange type component is shown in Fig. 2, and comprises an inductor base assembly 1, an effective ring assembly 2, and a water spray ring assembly 3; all three components are group weldments, and all the welds thereon are continuous. Weld seam, the burr should be cleaned after
welding, and tested with 0.6MPa pressure water, no leakage and other defects; the sensor base assembly and the effective ring assembly are connected by welding, and the water spray ring assembly is bolted to the sensor base. on.
Figure 2 shows the flange sensor
1. Sensor base 2. Effective circle 3. Spray ring
As shown in FIG. 3, the inductor base assembly includes a contact plate 1, a conductive plate 2, a cooling water pipe joint 3, a cooling water tank 4, and a water spray ring mounting ear plate 5. The contact plate and the conductive plate are arranged perpendicularly to each other, and the water box is welded on the conductive plate. After the hole is opened in the water box, the pipe joint is welded, and the spray ring mounting ear plate is vertically welded on the conductive plate. The base component is a left-right symmetric structure, and the insulating plates are arranged in the middle of the two conductive plates and then fixed by bolts. The induction ring assembly is a segmented structure (see FIG. 3), including an upper induction coil 6, a transition tube 7, and a lower induction coil 8. The induction ring assembly is made of square tube, the upper and lower induction coils are all one end arc, the transition tube is a spirally rising square tube, and the two ends are provided with interfaces, and the upper and lower induction coils are connected and welded.
The water spray ring assembly (see Fig. 3) comprises a fixed plate 9, a stud 10, and a water spray ring 11. The fixed plate is mounted on the inductor base by bolting, and the spray ring is mounted on the fixed plate through the stud.
Figure 3 sensor structure
1. Contact plate 2. Conductive plate 3. Cooling water pipe joint 4. Cooling water tank 5. Water spray ring mounting ear plate 6. Upper induction ring
7. Transition tube 8. Lower induction ring 9. Fixing plate 10. Stud 11. Spray ring
2. Matching the size determination method
The size of the special quenching sensor includes the inner diameter φ1' of the lower induction coil, the inner diameter φ2' of the upper induction coil, and the height H' of the induction coil. As shown in Fig. 4, the specific method for determining the size is as follows.
Figure 4 with size
(1) Lower induction ring inner diameter φ1' is used
Dimensional determination The size is determined according to the diameter of the outer diameter of the flange for induction hardening and the outer circle sensing distance λ1 required by the induction hardening process, that is, the inner diameter of the lower induction ring φ1' should be determined according to the following formula.
Φ1'=φD+2λ1
(2) Upper induction ring inner diameter φ2' with size determination
The size is determined according to the size of the inner hole diameter φd on the end face of the induction hardened flange part to be implemented and the inner diameter induction distance λ2 required according to the induction hardening process, that is, the inner diameter of the upper induction ring φ2' is used, and the following formula should be used according to the following formula Be determined
Φ2'=φd-2λ2
(3) Induction ring height H' with ruler
The size of the flange is determined according to the size of the flange outer height H of the induction hardening, and the height of the induction tube square tube a, the distance between the flange end face of the induction ring and the outer circumference of the flange according to the induction hardening process. It is determined by the vertical distance λ4 of the induction coil, that is, the height of the induction coil height H' should be determined according to the following formula.
H'=H +a +λ3+λ4
The flange member described herein has an outer diameter φD of 62 mm, an inner bore diameter φd of 44 mm, and a flange outer circle height H of 24 mm.
According to the requirements of induction hardening process, the distance λ1 between the outer circumference of the flange and the lower induction ring is 3mm, and the diameter of the inner hole on the end face of the flange is 1mm from the inner diameter of the upper induction ring. The distance between the end face of the induction quenching flange and the distance of the induction ring is λ3. It is 3mm, the vertical distance of the bottom of the outer circumference of the flange is 2mm from the vertical distance of the induction coil, and the height a of the induction tube is 12mm.
According to the above situation, determine the matching size of the quenching sensor used as follows:
3. Induction hardening process test results
After the test piece was subjected to induction heat treatment according to the required process and using the inductor designed and fabricated as described above, no defects such as cracks were found after the magnetic particle flaw detection, and the hardness and metallographic phase of the flanged part subjected to the quenching work were tested. Meet the requirements, in which the hardening depth of the quenching zone is shown in Figure 5.
Figure 5 Hardening zone depth test results
The above results show that the "special quenching inductor for flanged parts and the method for determining the size of the flanges" described in this paper can meet the requirements of the quenching process and have received good results.
Analysis of test results
(1) Improvement of quenching production efficiency
The quenching sensor adopts a segmented induction coil design to simultaneously heat the end face and the outer circular surface of the flange part, so that the flange can complete the quenching work at one time and improve the induction heating efficiency.
(2) continuous hardened layer
The sensor solves the problem of the size of the quenching inductor and the parts by adopting the matching size determining method, and ensures that the quenching position of each part is heated uniformly, and the hardened layer is uniformly continuous.
Conclusion
The chamfering and edge between the end face of the flange part and the outer circular surface are the design difficulties of the inductor. To achieve the quenching requirement, the design of the quenching inductor and the matching of the matching dimensions are determined by the following measures:
(1) In the design of the effective circle, the effective circle of the inductor is made by a rectangular tube, and the segmented structure is designed to simultaneously heat the outer circular surface and the end surface.
(2) By using the method of dimension determination, the dimensions of the effective circle are determined, the quenching quality of the part is effectively ensured, and a good quenching effect is obtained.
(3) The quenching inductor has novel concept, reasonable structure, reliable application, simple and feasible method, easy to implement, and has good practical value.
Unit: Luoyang Farah Induction Equipment Co., Ltd.
Source: Metal Processing (Hot Processing) Magazine
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