JP2009249695A - High-frequency induction-heating apparatus provided with cracking-preventive mechanism in spacer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high frequency induction-heating apparatus provided with a spacer with which even in the case of pressing a workpiece deformed at heating time with excessive pressing force, the breakage can be avoided. <P>SOLUTION: The high frequency induction-heating apparatus is provided with the spacers 7A, 8A, formed with non-magnetic body for holding a heating coil 9 and the workpiece 1 to a prescribed interval at the heating time. In both sides of the heating coil 9, respective side plate is disposed, and in the one side of the side plate 2, the spacer 7A at the front side is fixed and in the other side of the side plate 3, the spacer 7B at the back side is fixed. The above spacers 7A, 8A are respectively fixed to the front side and the back side of the heating coil 9, and when at least one of the spacer 7A and the spacer 8A, receives the outer power from the workpiece 1 deformed with the temperature-up, the interval near the workpiece abutting part with the spacer 7A and the spacer 8A, can be reduced. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a high-frequency heating apparatus including a nonmagnetic spacer that keeps the distance between a heating coil and a workpiece constant.

In order to uniformly heat the periphery of the workpiece with the high-frequency heating device, induction heating must be performed uniformly. For this purpose, the distance from the heating coil to the workpiece needs to be kept constant.
Therefore, conventionally, in order to keep the distance from the heating coil to the workpiece constant, a method has been adopted in which a high-frequency heating device is provided with a nonmagnetic spacer that does not move relative to the heating coil, and the workpiece is pressed against the nonmagnetic spacer. . If the work is kept pressed against the non-magnetic spacer, the heating coil can also be used to heat the heated part that revolves around the rotating shaft (revolves), such as the pin part of the crankshaft. The distance up to can be kept constant.
Such a high-frequency heating device is disclosed in Patent Document 1, for example.
Utility Model Registration No. 2601185

  FIG. 5 is a front view of a conventional high-frequency heating device, and FIG. 6 is a cross-sectional view taken along line AA of FIG. In the conventional high-frequency heating device, the heating coil 9 is sandwiched between the side plates 2 and 3, and the non-magnetic spacers 7A to 7C and 8A to 8C are fixed to the side plates 2 and 3, respectively. The nonmagnetic spacers 7A and 8A, 7B and 8B, and 7C and 8C are in a front-back relationship. Here, the nonmagnetic spacers 7A and 8A will be representatively described.

  As shown in FIG. 6, a rigid spacer 10 is disposed between the nonmagnetic spacers 7A and 8A, and two sets of side plates 2 and 3, the nonmagnetic spacers 7A and 8A, and the rigid spacer 10 are provided. It is fixed by countersunk bolts 4a and 4b and countersunk nuts 5a and 5b.

  The nonmagnetic spacers 7A and 8A are in contact (contact) with the workpiece 1 during heating, but the rigid spacer 10 is not in contact with the workpiece 1. That is, the nonmagnetic spacers 7 </ b> A and 8 </ b> A slightly protrude from the rigid spacer 10. Further, the nonmagnetic spacers 7A and 8A can be kept at a predetermined interval by the rigid spacer 10. The rigid spacer 10 is made of a material having rigidity, such as brass.

  By the way, if the state where the nonmagnetic spacers 7A and 8A are pressed against the workpiece 1 is maintained, the nonmagnetic spacers 7A and 8A may be cracked or cracked due to the load received from the workpiece 1. Patent Document 1 discloses a configuration that can reduce the stress applied to the nonmagnetic spacers 7A and 8A by the relative motion between the workpiece 1 and the heating coil 9 (nonmagnetic spacers 7A and 8A). Therefore, when the idea disclosed in Patent Document 1 is implemented, the force acting on the nonmagnetic spacers 7A and 8A is reduced, and the nonmagnetic spacers 7A and 8A can be protected.

  However, the present inventor has discovered that the external force acting on the nonmagnetic spacers 7A and 8A exists in addition to those caused by the relative movement of the workpiece 1 and the heating coil 9. That is, at the time of heating, the heated workpiece 1 is deformed. In FIG. 6, the workpiece | work 1 at the time of a deformation | transformation is shown with the code | symbol 1a.

  The deformed workpiece 1a may press the nonmagnetic spacers 7A and 8A. As a result of investigation by the present inventor, it has been found that the nonmagnetic spacers 7A and 8A are pressed by the workpiece 1a which is deformed at the time of heating and may be damaged. The crack 6 shown in FIG. 6 is an example of damage.

  In the configuration disclosed in Patent Document 1, the stress received by the nonmagnetic spacers 7A and 8A can be reduced by the relative movement between the workpiece 1 and the heating coil 9, but the workpiece is deformed by heating and heating during heating. The force received from 1a cannot be reduced.

  Then, this invention makes it a subject to provide the high frequency heating apparatus provided with the nonmagnetic spacer which can avoid a damage, even if it presses with the excessive pressing force to the workpiece | work deform | transformed at the time of a heating.

  The invention of claim 1 for solving the above-mentioned problem is a high-frequency heating apparatus provided with a spacer formed of a non-magnetic material that keeps the heating coil and the workpiece at a predetermined interval during heating, and is provided on both sides of the heating coil. Each side plate has a side plate, a front side spacer is fixed to one side plate, a back side spacer is fixed to the other side plate, and at least one of the front side spacer and the back side spacer is fixed. It is equipped with a spacer crack prevention mechanism characterized in that, when an external force is applied from a deformed workpiece due to temperature rise, the distance between the front spacer and the back spacer in the vicinity of the workpiece contact portion can be reduced. High frequency heating device.

In the first aspect of the invention, the distance between the front-side spacer and the back-side spacer in the vicinity of the work contact portion can be reduced. Therefore, when an external force is applied, the distance between the front-side spacer and the back-side spacer near the workpiece contact portion changes. Thereby, the stress which arises in both the spacers at the time of the effect | action of external force can be reduced, and the damage of both spacers can be avoided.
Specifically, when the heated workpiece is deformed, one or both of the front side spacer and the back side spacer may be pressed with an excessive force. At this time, if the invention of claim 1 is implemented, the spacer on the front side and the spacer on the back side can be narrowed to prevent both spacers from being damaged. That is, if the acting external force is not large enough to destroy the front side spacer and the back side spacer, the both spacers are not damaged even if the distance between the spacers is not reduced. Therefore, the interval between the work contact portions of both spacers is reduced when the magnitude of the external force that acts is greater than or equal to a predetermined value.

  The invention according to claim 2 is a high-frequency heating device including a spacer formed of a non-magnetic material that keeps the heating coil and the workpiece at a predetermined interval during heating, wherein the heating coil includes a front side spacer and a back side spacer. When at least one of the front side spacer and the back side spacer receives external force from the deformed workpiece due to temperature rise, the distance between the spacers on the workpiece placement side can be restored. In order to reduce the size, the high-frequency heating apparatus provided with a spacer crack prevention mechanism is characterized in that an elastic member is provided on the work arrangement side between both spacers.

In the invention of claim 2, since the elastic member is provided on the workpiece arrangement side between the front side spacer and the back side spacer, the distance between both spacers can be changed at least partially. Therefore, when at least one of the two spacers receives an external force from the workpiece deformed due to the temperature rise, it is possible to avoid damage to the spacers by reducing the interval on the workpiece arrangement side between the spacers. .
Further, after the distance between the front side spacer and the back side spacer on the workpiece arrangement side fluctuates (reduces), it can be restored to the original interval by the elastic member.
Further, if the rigid member is provided between all the spacers except for the portion where the elastic member is provided, the distance between the spacers can be reliably maintained.
The elastic member is preferably made of a nonmagnetic material so as not to be magnetized.
If the front side spacer and the back side spacer are respectively fixed to the side plates disposed on both sides of the heating coil, the front side spacer and the back side spacer have a high degree of freedom and are easily displaced.

  By implementing the present invention, it is possible to improve the durability of the spacer that keeps the distance between the heating coil and the workpiece of the high-frequency heating device constant.

  FIG. 1 is a partial longitudinal sectional side view showing a state in which the nonmagnetic spacers 7A and 8A of the high-frequency heating device 11 embodying the present invention are in contact with the workpiece 1. FIG. 2 is a partially longitudinal side view of FIG. 1 when the workpiece 1 is heated and deformed. In each configuration shown in FIG. 1, the same components as those shown in FIG.

  The work 1 is a pin portion of the crankshaft, and the pin portion rotates (revolves) around the rotation axis of the crankshaft. The high-frequency heating device 11 includes a semi-open saddle type heating coil 9 and heats the pin portion (work 1) of the crankshaft.

  The rigid spacer 12 shown in FIG. 1 is greatly different from the rigid spacer 10 shown in FIG. That is, the rigid spacer 12 is shorter than the rigid spacer 10 and is penetrated only by the countersunk bolt 4a. Further, the countersunk bolt 4b is provided with a spiral spring 13 (elastic member). The spiral spring 13 is compressed between the nonmagnetic spacers 7A and 8A and presses the nonmagnetic spacers 7A and 8A outward. If the distance between the nonmagnetic spacers 7A and 8A is small, a spring washer can be used instead of the spiral spring 13 as the elastic member.

  Furthermore, since the side plates 2 and 3 are connected by the countersunk bolt 4b and the countersunk nut 5b, the nonmagnetic spacers 7A and 8A cannot be expanded beyond the bolt fixing length, but the distance becomes narrower. Can be slightly displaced. The nonmagnetic spacers 7A and 8A are made of a nonconductive material such as cemented carbide or ceramics.

  Further, the rigid spacer 12 and the helical spring 13 (elastic member) can be attached to and detached from the high-frequency heating device 11 with the countersunk bolts 4a and 4b. That is, the rigid spacer 12 and the helical spring 13 (elastic member) can be exchanged.

  Now, assuming that the workpiece 1 is heated, the workpiece 1 is deformed as shown by a broken line 1a as shown in FIG. 2, and a pressing force acts on the nonmagnetic spacers 7A and 8A. The corner portions 7a and 8a of the nonmagnetic spacers 7A and 8A are particularly easily pressed. The magnitude of this pressing force may become excessive.

  As a result, the non-magnetic spacers 7A and 8A are slightly displaced on the workpiece contact portion side (lower portion as viewed in FIG. 2) around the flat bolt 4a (rigid spacer 12). That is, the nonmagnetic spacers 7A and 8A are displaced in the directions (inside) indicated by the arrows B and C as shown in FIG. 2 against the elastic force of the spiral spring 13. At that time, some play occurs between the countersunk bolt 5a, countersunk nut 5b, and the side plates 2 and 3. In FIG. 2, the alternate long and two short dashes line indicates the positions of the nonmagnetic spacers 7A and 8A before being displaced.

Compared with the conventional non-magnetic spacer, as a result of being able to be displaced by the difference between the two-dot chain line and the solid line, the non-magnetic spacer 7A, 8A embodying the present invention receives a pressing force from the workpiece 1a. In addition, the internal stress is not improved and cracks and cracks do not occur. In the conventional configuration (configuration shown in FIG. 6), when a pressing force is applied, the force cannot be released, so that the internal stress of the nonmagnetic spacer itself is improved and eventually breaks.
As a result of investigating the identity of the pressing force acting on the nonmagnetic spacers 7A and 8A during heating, the present inventor has been able to take measures to avoid the breakage of the nonmagnetic spacers 7A and 8A as described above. In addition, since the distance between the heating portion of the workpiece 1 and the heating coil does not vary while avoiding the breakage of the nonmagnetic spacers 7A and 8A, it can be heated satisfactorily.

  Next, another embodiment of the present invention will be described with reference to FIGS. FIG. 3 is a partial longitudinal sectional side view of a high-frequency heating device embodying the present invention different from FIG. FIG. 4 is a partially longitudinal side view of a high-frequency heating device embodying the present invention different from those shown in FIGS.

  In the example shown in FIG. 3, the rigid spacer 14 and the compression spring 15 are characterized. The width of the rigid spacer 14 varies between the countersunk bolts 4a and 4b, and the countersunk bolt 4b passes through the hole 14c of the small width part 14a having a small width. A hole 14b is provided near the tip of the narrow portion 14a. A compression spring 15 is inserted into the hole 14b. The compression spring 15 presses the nonmagnetic spacers 7A and 8A while being supported by the hole 14b of the rigid spacer 14. Alternatively, the compression spring 15 having a large spring constant may be employed, and may be installed in the hole 14b with a natural length and compressed when the nonmagnetic spacers 7A and 8A are displaced inward even a little. That is, the “compression spring 15” does not necessarily need to be compressed at all times, and at least when the nonmagnetic spacers 7A and 8A receive a pressing force from the work 1 (work 1a), if a restoring force is generated. Good.

  As shown in FIG. 3, when the narrow width portion 14a is provided in the rigid spacer 14, a gap 16 is generated between the small width portion 14a and the nonmagnetic spacers 7A and 8A. Therefore, when the nonmagnetic spacers 7A and 8A receive a pressing force from the workpiece 1, the presence of the gap 16 allows the nonmagnetic spacers 7A and 8A to be displaced in a direction in which the gap 16 narrows. In the example shown in FIG. 3, the countersunk bolt 4b passes through the hole 14c of the small width part 14a. However, the small width part 14a can be provided only on the tip side (work 1 side) of the countersunk bolt 4b.

Next, still another embodiment will be described with reference to FIG.
In the example shown in FIG. 4, the rigid spacer 17 itself is made of a material having rigidity (such as brass). However, the rigid spacer 17 has a shape that is easily bent when an external force is applied, and further forms gaps 18 to 20. is doing.

  When the workpiece 1 is deformed during heating and the nonmagnetic spacers 7A and 8A are pressed, the rigid spacer 17 is bent to displace the nonmagnetic spacers 7A and 8A. At that time, the side plates 2 and 3 which are relatively easily bent are bent, and the nonmagnetic spacers 7A and 8A themselves are not deformed. Therefore, the internal stress of the nonmagnetic spacers 7A and 8A is not improved and is not destroyed. Further, when the temperature of the work 1 decreases and the pressing force does not act on the nonmagnetic spacers 7A and 8A, the side plates 2 and 3 return to their original shapes. Therefore, not only the nonmagnetic spacers 7A and 8A but also any members are not broken.

As described above, when the present invention is implemented, the nonmagnetic spacers 7A and 8A (same as 7B, 8B, 7C, and 8C) impair the original function of separating the workpiece 1 and the heating coil 9 by a predetermined distance. Therefore, the improvement of internal stress that is likely to occur during heating is suppressed.
Moreover, since the helical spring 13 and the compression spring 15 as elastic bodies are disposed directly under the heating coil 9, it is preferable to be made of a non-magnetic material.

  As described above, the high-frequency heating device 11 including the nonmagnetic spacers 7A and 8A described above has improved durability and extended life.

It is a partial vertical side view of the state which the nonmagnetic spacer of the high frequency heating apparatus which implemented this invention is contact | abutting to the workpiece | work. In FIG. 1, it is a partial vertical side view at the time of a workpiece | work being heated and deform | transforming. It is a partial vertical side view of the high frequency heating apparatus which implemented this invention different from FIG. FIG. 4 is a partially longitudinal side view of a high-frequency heating device that implements the present invention different from FIGS. 1 and 3. It is a front view of the conventional high frequency heating device. It is AA sectional drawing of FIG.

Explanation of symbols

1 Workpiece 2, 3 Side plate 4a, 4b Countersunk bolt 5a, 5b Countersunk nut 6 Crack 7A-7C Nonmagnetic spacer on the front side 8A-8C Nonmagnetic spacer on the back side 9 Heating coil 11 High frequency heating device 12 Rigid spacer

Claims (2)

  A high-frequency heating apparatus provided with a spacer formed of a non-magnetic material that keeps a heating coil and a work at a predetermined interval during heating, and side plates are arranged on both sides of the heating coil, The front side spacer is fixed, and the back side spacer is fixed to the other side plate, and at least one of the front side spacer and the back side spacer receives an external force from the deformed workpiece due to temperature rise. In this case, a high-frequency heating apparatus equipped with a spacer crack prevention mechanism characterized in that the distance between the front-side spacer and the back-side spacer in the vicinity of the workpiece contact portion can be reduced.   A high-frequency heating apparatus including a spacer formed of a non-magnetic material that keeps a heating coil and a workpiece at a predetermined interval during heating, the heating coil being disposed between a front spacer and a back spacer When at least one of the spacer on the front side and the spacer on the back side receives an external force from the workpiece that has been deformed due to the temperature rise, A high-frequency heating apparatus provided with a spacer crack prevention mechanism, characterized in that an elastic member is provided between the spacers on the workpiece arrangement side.

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