JPH04263007A - Induction hardening apparatus - Google Patents

Abstract

PURPOSE:To locally execute induction hardening while keeping accurate coil gap to the end face of long shaft parts. CONSTITUTION:A stopper 16 is penetrated through an induction coil 3 and protruded from the induction coil face by length of the desired coil gap and a material 1 to be quenched is held rotatably with a rotary roller 14 supported with a saddle 18, and by pushing the material 1 to be quenched with a pushing roller 14 inclined to the supporting axis, the part of quenching position is abutted on the protruded end of the stopper 16 and rotated to execute the induction hardening. The part of quenching position in the material 1 holds the constant coil gap between the induction coil, regardless of working accuracy of the whole length in the material to be quenched or the stopping position, etc., of the saddle 18.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an induction hardening apparatus.

0002

2. Description of the Related Art Conventionally, an induction hardening apparatus for locally hardening the shaft end surface A of a long rear axle shaft (hereinafter referred to as a hardened product) as shown in FIG. 6 has been shown in FIG. The hardened product 1 is vertically fixed to the tip of a C-shaped saddle 4 by fixing pins 5 and 6 which are vertically disposed so as to face each other. The upper fixing pin 5 passes through the high-frequency coil 3 connected to the transformer 11, and the lower fixing pin 6 is rotated by the rotary motor 8, so that the hardened part of the shaft end face of the hardened product 1 passes through the high-frequency coil 3. 3 and rotates while maintaining a constant coil gap d. The saddle 4 is attached to a feed screw 13 vertically disposed on the feed motor 7 so as to be able to rise and fall freely, and the saddle 4 moves up and down by the rotation of the feed motor 7, and stops going up and down by the rising end limit switch 9 and the falling end limit switch 10. do.

When locally hardening the shaft end face of a hardened product using an induction hardening device, the coil gap determines the hardening quality such as the hardening depth and hardening range, so it is necessary to accurately control the coil gap. There is. Figure 7 is a partially enlarged view of the hardened shaft end surface, and shows the coil gap and hardening depth E.
The relationship between the hardening range and the hardening range φD is shown in FIG.

Therefore, even in the conventional device shown in FIG.
The coil gap d was measured with a caliper, and if it was not within the set range, the position β of the rising end limit switch 9 was adjusted manually to manage the coil gap.

[0005]

[Problems to be Solved by the Invention] However, in conventional induction hardening equipment that locally hardens shaft end faces, the hardened product is supported vertically and moved up and down, and the axial center of the hardened product is Since the center hole provided on the upper and lower end faces of the product is supported by the upper and lower fixing pins, there is a variation (±0.1 mm) in the accuracy of raising and stopping the saddle that supports the hardened product, or the overall length of the hardened product. There was a problem in that the coil gap d varied due to variations in accuracy (±0.5 mm), resulting in inconsistent hardening quality. Incidentally, the actual measured values of the variation in the coil gap d of the conventional device are as shown in FIG.

Furthermore, when hardening products with different overall lengths, it is necessary to change the rising end 9 of the saddle 4 depending on the total length of the hardening product. required equipment. Furthermore, since it is a vertical type, it is difficult to automate the installation and removal of hardened products, making it difficult to save labor.

The present invention has been made in order to solve the above-mentioned problems of the conventional induction hardening apparatus for locally hardening the shaft end face of a hardened product. Regardless of variations in stopping accuracy or variations in overall length dimensional accuracy of hardened products, the coil gap can be maintained accurately, and a wide variety of products can be handled without the need for troublesome operations such as switching the rising end. The purpose is to provide an induction hardening device that is easy to automate.

[0008]

[Means for Solving the Problems] The induction hardening apparatus of the present invention includes a high-frequency coil, a stopper that penetrates the high-frequency coil and protrudes from the high-frequency coil surface by a desired coil gap length, and rotates a hardened product. and a hardened product holding device that rotates while pressing the hardened part against the protruding end of the stopper.

[0009]

[Operation] The stopper passes through the center of the high-frequency coil and protrudes from the high-frequency coil by the length of the desired coil gap. The hardened product holding device rotatably holds the hardened product and rotates by pressing the hardened part against the protruding end of the stopper, so the hardened part of the hardened product is related to the machining accuracy of the entire length of the hardened product. A constant coil gap is maintained between the high frequency coil and the high frequency coil. In addition, the coil gap is not determined by the movement of the saddle that moves the hardened product holding device, but is determined by pressing the hardened part against the protruding end of the stopper, so the coil gap is affected by the stopping accuracy of the saddle. I never receive it. Furthermore, since the coil gap can be accurately kept constant regardless of the overall length of the hardened product, it is possible to handle a wide variety of hardened products without requiring complicated operations such as switching the rising end. Moreover, since it is possible to use a horizontal type, long quenched products are transported horizontally in the processes before and after the process, making it easy to automate the apparatus.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a side view of one embodiment of the present invention. An annular high frequency coil 3 is vertically supported by a transformer 11, and a horizontally supported ceramic stopper 16 passes through the center of the high frequency coil 3. The length d that this ceramic stopper 16 protrudes from the high frequency coil 3
can be adjusted by an adjustment screw 17 attached to the base of the ceramic stopper 16.

As shown in the roller arrangement diagram in FIG. 2 and the plan view in FIG. 3, two sets of rotating rollers 15 are pivotally supported on the saddle 18 and rotated by the rotating motor 8. The hardened product 1 is placed on these rotating rollers 15, and rotates with its shaft end facing the protruding end of the ceramic stopper 16.

The hardened product 1 supported by the rotating roller 15 is pressed down by the pressing roller 14 which is urged downward by the hydraulic cylinder 19. This presser roller 14 is provided with an inclination angle θ of about 30°, and when the hardened product 1 is rotated by the rotating roller 15, a thrust force γ acts on the high frequency coil 3 side as shown in FIG. Arrival 1
The shaft end surface of the ceramic stopper 16 is pressed against the protruding end of the ceramic stopper 16. Note that since the center hole 2 is bored in the shaft end surface, the tip of the ceramic stopper 16 has a flat shape.

The saddle 18 is attached to a feed screw 13 horizontally supported by the feed motor 7 via a bracket having an internal thread, and moves forward or backward as the feed screw 13 rotates.

The operation of the device of this embodiment will be explained as follows.
First, the length d by which the ceramic stopper 16 projects from the high-frequency coil 3 is adjusted using the adjustment screw 17 attached to the base of the ceramic stopper 16. Next, the hardened product 1 is set on the rotating roller 15, and the hydraulic cylinder 1 is
9 is activated to press down the hardened product 1 with the holding roller 14.

Next, the feed screw 13 is moved by the feed motor 7.
is rotated to move the saddle 18 forward to bring the shaft end surface of the hardened product 1 close to the protruding end of the ceramic stopper 16. Next, when the rotary roller 15 is rotated, the hardened product 1 is advanced toward the high frequency coil 3 by the thrust force γ of the presser roller 14, as shown in FIG. pressed against. Therefore, a predetermined coil gap d is maintained between the shaft end surface of the hardened product 1 and the high frequency coil 3.

When the variation in the coil gap d was measured using the device of this embodiment, the results shown in FIG. 5 were obtained. As is clear from the measured value of the variation in the coil gap d shown in FIG. 5, it is reduced to about 1/8 compared to the measured value of the variation in the coil gap d of the conventional device shown in FIG. The effect was confirmed.

[0017]

Effects of the Invention As described in detail above, the induction hardening apparatus of the present invention allows the high-frequency coil to pass through the stopper and protrude from the high-frequency coil surface by a desired length of the coil gap,
The hardened product is rotatably held by a hardened product holding device, and the hardened part is pressed against the protruding end of the stopper and rotated to perform induction hardening, and the hardened part of the hardened product is Regardless of the machining accuracy of the total length of the incoming product, a constant coil gap is maintained with the high frequency coil. In addition, the coil gap is not determined by the movement of the saddle that moves the hardened product holding device, but is determined by pressing the hardened part against the protruding end of the stopper, so the coil gap is affected by the stopping accuracy of the saddle. I never receive it. Furthermore, since the coil gap can be accurately kept constant regardless of the overall length of the hardened product, it is possible to handle a wide variety of hardened products without requiring complicated operations such as switching the rising end. Moreover, since it is possible to use a horizontal type, long quenched products are transported horizontally in the processes before and after the process, making it easy to automate the apparatus.

[Brief explanation of the drawing]

FIG. 1 is a side view of an embodiment of the invention.

FIG. 2 is a diagram showing the relationship between the roller and the hardened product in the embodiment of FIG. 1;

FIG. 3 is a plan view of the embodiment device of FIG. 1;

FIG. 4 is a side view illustrating the principle of maintaining the coil gap.

FIG. 5 is a diagram showing variations in coil gap when the embodiment device of FIG. 1 is used.

FIG. 6 is an external view of the hardened product.

FIG. 7 is a partially enlarged view of the shaft end surface A of the hardened product.

FIG. 8 is a side view of a conventional induction hardening device.

FIG. 9 is a diagram showing the relationship between the coil gap, quenching depth, and quenching range.

FIG. 10 is a diagram showing variations in coil gap when a conventional induction hardening device is used.

[Explanation of symbols]

1 Quenched product
3 High frequency coil 4 Saddle
7 Feed motor 8 Rotation motor
9 Rising end limit switch 10 Lowering end limit switch 11
Transformer 13 Feed screw
14 Holding roller 15 Rotating roller
16 Ceramic stopper 17 Gap adjustment screw 1
8 Saddle 19 Hydraulic cylinder

Claims (1)

[Claims] 1. A high-frequency coil; a stopper that penetrates the high-frequency coil and protrudes from the high-frequency coil surface by a desired coil gap length; An induction hardening device characterized by comprising a hardened product holding device that rotates while being pressed against the hardened product.