JP2578034B2 - Wheel heat treatment method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of heat-treating a metal wheel rolling on a rail, in which only a tread portion and a flange are hardened.

[0002]

2. Description of the Related Art Conventionally, when a hardening process is performed on a metal wheel formed of a tread portion, a flange, and a boss formed by press working, (1) in a state where the entire surface of the wheel is exposed,
A method of performing gas carburizing quenching and tempering, (2)
To apply the hardening treatment only to the tread and the flange, apply a carburizing inhibitor to the parts other than the tread and the flange of the wheel, and then apply the carburizing inhibitor to the wheel,
A method of stripping and removing a carburizing inhibitor after performing gas carburizing and quenching and tempering treatment has been implemented.

[0003]

In the case of the above-mentioned conventional method (1), the entire wheel comprising the tread, the flange and the boss is hardened, so that a bearing fitting portion having a bearing stopper is provided on the boss of the wheel. When forming by cutting, expensive carbide cutting tools are required, cutting is also difficult to perform, and the boss is hardened, so the performance stability when the wheel is fitted to the axle with a bearing incorporated is poor. There is a disadvantage that.
In the case of the above method (2), it is necessary to apply a carburizing inhibitor to portions other than the tread portion and the flange of the wheel, and to remove and remove the carburizing inhibitor after quenching and tempering with gas. It is complicated. In particular, when a large number of wheels are subjected to a hardening treatment, it is necessary to apply and remove a carburizing inhibitor for each wheel, so that the processing operation is extremely complicated.

[0004]

SUMMARY OF THE INVENTION According to the present invention, in order to advantageously solve the above-mentioned problems, a tread portion 1, a flange 2, and a boss 3 are provided.
After the metal wheels 4 are manufactured by press working, a plurality of wheels 4 are fitted to the shaft 5 in the same direction, and the flange 2 of the wheel 4 at one end of the wheel train is connected to one end of the shaft 5. At the other end of the shaft 5 to fasten the wheel train, and then to the wheel train supported by the shaft 5 for gas carburizing. A quenching and tempering treatment is performed so that the boss 3 is not hardened, and
In addition, a wheel in which only the flange 2 is hardened can be obtained.

[0005]

FIG. 2 shows a wheel 4 formed by pressing a circular steel plate. A frusto-conical flange 2 is continuously provided at one end of a cylindrical tread portion 1; At the other end of the tread portion 1, a boss 3 located inside the tread portion 1 is continuously provided via a semicircular portion 9.

When the tread portion 1 and the flange 2 of the wheel 4 shown in FIG. 2 are subjected to hardening treatment, as shown in FIG. 1, a number of wheels 4 are fitted in the same direction on a metal shaft 5, and The flange 2 of the wheel 4 at one end of the wheel train fitted to the shaft 5 is connected to a circular flange 6 connected to one end of the shaft 5.
And the other end of the shaft 5 has a washer 10
And a male screw portion 7 provided at the other end of the shaft 5.
A screwing member 8 composed of a female screw member is screwed into the nut, and the tightening member 8 is rotated in the tightening direction to tighten the wheel train.
The circular flange 6 is pressed against the flange 2 of the wheel 4 at the end.

Next, gas carburizing and quenching are performed on the wheel train fastened by the shaft 5 having the circular flange 6 and the fastening member 8, and then tempering is performed. In this way, a surface hardened layer 11 is formed on the surface of the tread portion 1 and the exposed surface of the flange 2 by a heat hardening process (see FIG. 3). The surface hardened layer 11 has a surface hardness of Hv (Vickers hardness) 610 or more, and the thickness of the surface hardened layer 11 is about 0.7.
mm.

Next, as shown in FIG. 3, a bearing fitting portion 13 having a bearing stopper 12 inside the boss 3 is cut and formed. Next, as shown in FIGS. 4 and 5, a bearing 15 composed of a ball bearing having a sealing material 14 fitted and locked on both sides is attached to the boss 3.
After being fitted into the bearing fitting portion 13 inside, a number of retaining projections 16 that engage with the outer ring of the bearing 15 are formed upright around the tip of the boss 3 by a hitting tool.

FIG. 6 shows another example of tightening and holding a wheel train, in which a lower end of a vertical shaft 5 having a circular flange 6 at a lower portion is a bottom of a heat treatment frame (container). 1
7, each of the wheels 4 is fitted to the shaft 5 such that the flanges 2 of the multiple wheels 4 are located on the lower side, and the flange 2 of the lowest wheel 4 is a circular flange 6
And a tightening member 8 composed of a weight is fitted to the upper end of the shaft 5, and the wheel train is tightened by the weight of the tightening member 8.

[0010]

According to the present invention, the tread portion 1 and the flange 2
After manufacturing a metal wheel 4 made of a metal and a boss 3 by pressing, a plurality of wheels 4 are fitted to a shaft 5 in the same direction, and the flange 2 of the wheel 4 at one end of the wheel train is connected to the shaft 5. Is engaged with a peripheral edge of a circular flange 6 provided at one end of the wheel train, and the wheel train is fastened by a fastening member 8 provided at the other end of the shaft 5. , Gas carburizing and tempering,
The hardening process can be performed only on the tread portion 1 and the flange 2 without performing the hardening process on the boss 3 of the press-formed wheel 4. Therefore, the wear resistance of the tread portion 1 and the flange 2 on the wheel 4 is improved. The bearing fitting portion 13 having the bearing stopper 12 can be easily formed by cutting using a normal cutting tool that is not a carbide cutting tool. By providing the bearing fitting portion 13 having the bearing 12 and incorporating the bearing 15, the performance of the wheel 4 incorporating the bearing 15 can be stabilized. In the case of the present invention,
The wheel 4 in which only the tread portion 1 and the flange 2 are hardened without the boss 3 being hardened can be manufactured by the above simple means.

[Brief description of the drawings]

FIG. 1 is a partially longitudinal side view showing a state in which a number of wheels are arranged in series in the same direction and are fastened and held.

FIG. 2 is a longitudinal sectional side view showing a press-formed wheel.

FIG. 3 is a longitudinal sectional side view showing a state in which a bearing fitting portion having a bearing stopper is formed on a boss of a hardened wheel.

FIG. 4 is a longitudinal sectional side view showing a state in which a bearing is incorporated in a boss of a hardened wheel.

FIG. 5 is a front view of the wheel with a built-in bearing shown in FIG. 4;

FIG. 6 is a partially longitudinal side view showing another example of a means for fastening and holding a wheel train.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tread surface part 2 Flange 3 Boss 4 Wheel 5 Shaft 6 Circular flange 7 Male screw part 8 Tightening member 9 Semicircular part 10 Washer 11 Surface hardened layer 12 Bearing stopper 13 Bearing fitting part 15 Bearing 16 Retaining projection 17 Heat treatment frame Bottom of

Claims (1)

(57) [Claims] After manufacturing a metal wheel 4 comprising a tread portion 1, a flange 2 and a boss 3 by press working, a plurality of wheels 4 are fitted in a same direction to a shaft 5 and one end of a wheel train. The flange 2 of the wheel 4 is engaged with the periphery of a circular flange 6 provided at one end of the shaft 5, and the wheel train is tightened by a tightening member 8 provided at the other end of the shaft 5. A heat treatment method for wheels in which a wheel train supported by a shaft 5 is subjected to gas carburizing quenching and tempering.