JP2007262440A - Induction heating apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To uniform the hardness of a tempered outer ring of a constant velocity universal joint by reducing the temperature difference in the outer ring. <P>SOLUTION: An outer coil 10 for induction heating into which the shaft part 13 of a work 3 (the outer ring of the constant velocity universal joint) is inserted, is provided above a work receiving table 4' for placing the work 3 thereon, and on the receiving table 4', an inner coil 11 for induction heating to be inserted into the cup part 14 of the work 3 is arranged and also, in each of the outer coil 10 and the inner coil 11, high frequency electric sources 15, 16 are arranged. In the receiving table 4, an ascending/descending means 12 is provided so as to ascend/descend the receiving table 4. Then, when the work 3 is set on the receiving table 4' and the receiving table 4' is ascended, since the shaft part and the cup part which are to be induction-heated can be respectively set to the outer coil 10 and the inner coil 11, the hardened parts in the shaft part 13 and the cup part 14 are simultaneously tempered at the same temperature by simultaneously operating both coils 10, 11. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an induction heating device for a constant velocity joint outer ring.

  In the heat treatment of the constant velocity joint outer ring, a tempering method using induction heating is used. In the tempering using induction heating of the constant velocity joint outer ring, a round solenoid coil 1 as shown in FIGS. 5A and 5B or a hairpin coil 2 shown in FIGS. 6A and 6B is used. It is done.

  For example, (Patent Document 1) describes a method in which induction heating coils are provided on the outside of the shaft portion of the outer ring and the cup portion, respectively, and induction heating and water injection are performed for tempering.

  That is, in general, in such heat treatment, for example, as shown in FIGS. 5 (b) and 6 (b), after the outer ring (work) 3 of the product is placed on the work cradle 4, the cradle 4 Move into the coils 1 and 2 together. The moved work 3 is induction-heated by passing a high-frequency current through the coils 1 and 2. At this time, the workpiece 3 may be rotated and heated in order to reduce variation in temperature in the circumferential direction. At this time, the magnitude and frequency of the coil current take various values depending on the type and shape of the workpiece 3.

  Next, when the workpiece 3 is raised to a predetermined temperature necessary for tempering by induction heating, the high-frequency current is stopped and held for a predetermined time, and then the workpiece 3 is cooled with cooling water to finish the processing. This cooling may be performed inside the coils 1 and 2 or at a cooling position provided at another position.

Japanese Patent Laid-Open No. 5-9584

  However, in the tempering method described above, the cured portion has an outer diameter in the shaft portion, whereas the cured portion exists in the inner diameter in the cup portion. Since the shaft portion and the cup portion are different in shape and mass in the circumferential direction and the axial direction, the entire region cured by quenching can be tempered at the same temperature by heating from the outside. For example, FIG. As shown in b), it is necessary to adjust the shape of the coils 1 and 2 (coil turn interval l and diameter) and the positional relationship L between the workpiece 3 and the coils 1 and 2. However, since the coils 1 and 2 are made of copper, it is not easy to change the shape.

  As shown in FIG. 8, the constant velocity joint includes a tripod type constant velocity joint outer ring having three track grooves 22 as shown in FIG. 8. This outer ring is a round solenoid coil (indicated by an imaginary line). ) When heated in a state of being placed in 1, the temperature of the large inner diameter portion 21 that is close to the coil 1 and is thin is higher than the portion of the small inner diameter portion 5 that is far from the coil 1 and is thick. There is.

  In general, in a portion cured by quenching, when the tempering heating time is the same, the amount of decrease in hardness increases as the tempering heating temperature increases. Therefore, the hardness of the large inner diameter portion 21 after tempering is lower than that of the small inner diameter portion 5. Further, in the constant velocity joint, the hardness after tempering is defined based on the product strength, and when trying to obtain the prescribed hardness in the small inner diameter portion 5, the large inner diameter portion 21 becomes lower than the small inner diameter portion 5, There is a problem of lowering the lower limit or the lower limit of the regulation.

  Further, a method of separately tempering the shaft portion with the outer coil and the cup portion with the inner coil is conceivable, but the apparatus becomes large and the processing time is doubled or more because the overheating position is individually provided.

  Therefore, an object of the present invention is to first enable tempering of the cured portion of the shaft portion and the cup portion at the same temperature at the same time. Next, the tempering coil for different product shapes can be shared. Furthermore, it is intended to improve workability and shorten processing time.

  In order to solve the above problems, the present invention employs a configuration in which a high frequency power source is provided for each of the outer coil into which the shaft portion of the constant velocity joint outer ring is inserted and the inner coil to be inserted into the cup of the joint outer ring. is there.

  By adopting such a configuration, the coil for heating the shaft portion and the cup portion of the constant velocity joint outer ring is individually provided, and the high frequency power source is also provided individually. As a result, the temperature balance between the shaft portion and the cup portion can be adjusted by adjusting each high-frequency power source. Furthermore, since the inner coil is inside the cup portion, for example, the small inner diameter portion of the tripod type constant velocity joint outer ring is close to the inner coil. Therefore, the temperature is likely to rise as compared with the case where there is a coil on the outer periphery, and the temperature difference from the large inner diameter portion can be reduced. As a result, the hardness after tempering of the cured portion of the shaft portion and the cup portion can be kept uniform.

  At this time, the outer coil is provided above the work cradle on which the constant velocity joint outer ring is placed, while the cradle is provided with the inner coil, and either the cradle or the outer coil is raised or lowered. The structure provided with the raising / lowering means to make it employ | adopt is employable.

  If such a structure is employ | adopted, a constant velocity joint outer ring will be mounted in a workpiece cradle with the opening of a cup part facing down. At that time, the inner coil of the cradle is inserted into the opening of the cup. When the cradle is raised or the outer coil is lowered by the lifting means in this state, the shaft of the outer ring can be inserted into the outer coil. Therefore, just by setting the workpiece on the cradle in this way, the outer coil and the inner coil can be set on the shaft part and the cup part for induction heating, respectively. Can be tempered by induction heating at the same time. As a result, workability can be improved and processing time can be shortened.

  At this time, by adopting a structure including lifting means that raises or lowers the inner coil independently of the work table, the inner coil is made to stand by below the work cradle and the work is placed on the work cradle. If it is made to protrude from the end, it is possible to save the trouble of covering the inner coil when setting the workpiece.

  With this configuration, the temperature difference between the shaft portion and the cup when induction heating is reduced, and the inner diameter of the tripod type constant velocity joint outer ring is reduced by adopting the inner coil. Since the temperature difference in the inner diameter portion can be reduced, variation in the amount of partial hardness reduction due to tempering can be reduced, and the hardness after tempering can be kept uniform. Moreover, since the adjustment of the tempering temperature balance between the shaft portion and the cup portion can be performed by adjusting the output of the high frequency power source provided in each coil, the quality adjustment time can be shortened. Furthermore, if the output is adjusted, the heating coil can be shared between workpieces having different shapes and weights.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  The tempering device of this embodiment has an outer coil 10 and an inner coil 11 as shown in FIGS. 1A to 1C, and the outer coil 10 mounts a constant velocity joint outer ring (hereinafter referred to as a workpiece) 3. It is provided above the workpiece cradle 4 '. On the other hand, the inner coil 11 is provided on the cradle 4 ′, and the cradle 4 ′ is supported by the lifting means 12.

  The outer coil 10 is used for induction heating by inserting the shaft portion 13 of the work 3 and covering the entire shaft portion 13 (not covering the cup portion 14). As shown in FIG. The high frequency power supply 15 is connected. Moreover, in this form, although the multiturn coil is used for the outer coil 10, since the axial part 13 of the workpiece | work 3 is inserted, it can also be made to use a hairpin coil like FIG.2 (b). .

  The inner coil 11 is inserted into the cup portion 14 of the work 3 and is used for induction heating of the inside of the cup portion 14 and is connected to a high-frequency power source 16 dedicated to the inner coil as shown in FIG. . In this embodiment, a multi-turn coil is used as the inner coil 11 so that the inner coil 11 can be inserted into the cup part 14. However, any coil other than the multi-turn coil can be used as long as it can be inserted into the cup part 14. I do not care.

  Incidentally, the independent high frequency power supply 15 for the outer coil and high frequency power supply 16 for the internal coil are, for example, transistor type inverter power supplies, which are not shown, but are connected to a control sequencer, a personal computer or the like for output. The heating time and frequency can be controlled individually.

  In this embodiment, the work cradle 4 ′ is vertically attached to the upper surface of the cradle 4 ′ as shown in FIG. 1, and the inner coil 11 is placed on the cradle 4 ′. 3 (cup part 14). On the other hand, lifting means 12 is connected to the back surface of the work cradle 4 '.

  The elevating means 12 is constituted by, for example, a shaft or a frame connected to the cradle 4 ′ and a servo motor, an air cylinder or a hydraulic cylinder for driving the shaft, a frame, etc., and can raise or lower the cradle 4 ′. It is like that.

  This configuration is configured as described above. In this tempering apparatus, as shown in FIG. 1A, the cradle 4 'is lowered to a position where it does not interfere with the outer coil 10 when the workpiece is attached or detached. As shown in FIG. 1B, the work 3 is placed.

  That is, the work 3 here is a tripod type constant velocity joint outer ring having three track grooves as shown in FIG. 8 and the outer ring is covered with the inner coil 11 with the opening of the cup portion 14 facing downward. Place on cradle 4 '. Next, the elevating means 12 is operated to raise the cradle 4 ′, the work 3 and the inner coil 11. Then, as shown in FIG. 1C, the lifted work 3 stops the elevating means 12 in this state because the shaft portion 13 is inserted into the upper outer coil 10. Then, the high frequency power sources 15 and 16 of the outer coil 10 and the inner coil 11 are actuated to simultaneously heat the inside of the shaft portion 13 and the cup portion 14 of the work 3.

  At that time, the induction heating of the shaft portion 13 and the cup portion 14 individually adjusts the output of the high frequency power sources 15 and 16 of the coils 10 and 11. As a result, the temperature difference between the shaft portion 13 and the cup portion 14 is reduced, the variation in the partial hardness reduction due to tempering is reduced, the hardness reduction due to tempering is made constant, and the hardness after tempering is uniform. Can keep.

  At that time, as described above, the temperature balance at the time of tempering of the shaft portion 13 and the cup portion 14 is adjusted by adjusting the outputs of the high-frequency power sources 15 and 16 provided in the coils 10 and 11, respectively. Also, quality adjustment time can be shortened. Further, by adjusting the output of the high frequency power sources 15 and 16 of the coils 10 and 11 as described above, the temperature difference between the shaft portion 13 and the inside of the cup portion 14 can be reduced. The induction heating coils 10 and 11 of the coils 10 and 11 can be shared.

  In the workpiece (tripod type constant velocity joint outer ring) 3 thus induction-heated, in particular, the inner coil 11 is provided inside the cup portion 14 so that, for example, the small inner diameter portion 5 shown in FIG. Therefore, the temperature is likely to rise as compared with the case where there is a coil on the outer periphery, and the temperature difference from the large inner diameter portion 21 becomes small as shown in FIGS. 3 (a) and 3 (b). As a result, the prescribed hardness can be easily obtained at both portions.

  As shown in FIG. 4, the first embodiment is provided with elevating means for raising or lowering the inner coil 11 independently of the cradle 4'a. The work cradle 4'a according to the first embodiment includes: A through-hole 17 is provided in the center so that the inner coil 11 can pass therethrough so that the inner coil 11 and the cradle 4'a can be raised or lowered individually.

  Specifically, for example, as shown in FIG. 4, the shaft 12b that connects the inner coil 11 and the driving device passes through the inside of the frame 12a that connects the receiving base 4'a and the driving device. The base 4'a and the inner coil 11 (coil base 4'b) can be moved up and down independently. At this time, each shaft or frame is provided with a driving servo motor, an air cylinder, a hydraulic cylinder, or the like.

  Therefore, in this tempering apparatus, as shown in FIG. 4 (a), the cradle 4'a stands by to a position where it does not interfere with the outer coil when the workpiece is attached / detached, and the inner coil 11 is moved to the cradle. Wait below 4'a. In this state, the work 3 is placed as shown in FIG. Therefore, it is not necessary to cover the inner coil 11 when setting the work 3 on the cradle 4'a.

  Therefore, the workpiece 3 can be easily placed on the cradle. After the workpiece 3 is placed, the inner coil 11, the workpiece 3, the cradle 4 ′ a, and the coil pedestal 4 ′ b are connected to the shaft portion 13 of the workpiece 3. Until it is inserted into the outer coil 10. In this state, the elevating means 12a and 12b are stopped, the high frequency power supplies 15 and 16 of the outer coil 10 and the inner coil 11 are operated, and the inside of the shaft portion 13 and the cup portion 14 of the workpiece 3 are simultaneously induction heated.

  As described above, when the workpiece 3 is set on the cradle 4'a, the lifting / lowering means for raising or lowering the inner coil 11 independently of the cradle 4'a is provided. Save time and effort. Therefore, the processing time can be shortened. In addition, since another structure and effect are the same as embodiment, the same code | symbol is attached | subjected to FIG. 4, and the description is abbreviate | omitted.

  In the second embodiment, the outer coil 10 is raised and lowered instead of raising and lowering the workpiece cradle 4 'and the inner coil 11, and the outer coil 10 is supported by the portion indicated by the broken line 20 in FIG. The outer coil can be moved up and down by connecting to the driving device. Then, after the work 3 is placed on the cradle 4 ′, the outer coil 10 is lowered and the shaft portion 13 of the work 3 is inserted to perform induction heating. The other configurations and operational effects are the same as those of the embodiment and the actual example 1, and the description thereof is omitted.

(A)-(c) Action explanatory drawing of embodiment (A), (b) Block diagram of the embodiment (A), (b) Action explanatory drawing of embodiment (A)-(c) Action explanatory drawing of Example 1 (A), (b) Operation explanatory diagram of the conventional example (A), (b) Operation explanatory diagram of the conventional example (A), (b) Operation explanatory diagram of the conventional example Action explanatory diagram of conventional example

Explanation of symbols

3 Work 4 'Work cradle 4'a Work cradle 4'b Coil base 5 Small inner diameter portion 10 Outer coil 11 Inner coil 12 Lifting means 13 Shaft portion 14 Cup portion 15 High frequency power source 16 High frequency power source 21 Large inner diameter portion 22 Track groove

Claims (3)

  A high frequency power supply is provided for each of the outer coil into which the shaft portion of the constant velocity joint outer ring is inserted and the inner coil to be inserted into the cup of the joint outer ring, and the shaft portion and the cup portion are simultaneously heated at the same station for tempering. Induction heating device for performing.   The outer coil is provided above a work cradle on which a constant velocity joint outer ring is placed. On the other hand, the cradle is provided with the inner coil, and either the cradle or the outer coil is raised or lowered. The induction heating apparatus according to claim 1, further comprising an elevating means.   The induction heating apparatus according to claim 1, further comprising lifting means for raising or lowering the inner coil independently of the work table.

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