JPS6047326B2 - Method for hardening the inner surface of the socket of the outer ring of a constant velocity universal joint - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention applies high-frequency induction heating to the inner surface of the socket portion of the outer ring of a constant velocity universal joint mainly used in rotational force transmitting parts of automobiles and the like to uniformly harden the surface to a desired hardening depth. The present invention relates to a rubbing method, and particularly to a method for cooling the inner surface of a socket portion of a constant velocity universal joint outer ring heated by high frequency induction.

In general, a constant velocity universal joint represented by Japanese Patent Publication No. 53-1305 has a stem portion 2 on which a running wheel (not shown) is held with a bottom, and a bell mouth-shaped socket provided at one end of this stem portion 2, as shown in Fig. 5. 3, an inner ring 5 connected to a shaft 4 as a drive shaft, and a joint ball 6 inserted between the outer ring 1 and the inner ring 5 to transmit power.

Then, the outer surfaces of the stem portion 2 and the socket portion 3 of the outer ring 1 are subjected to surface hardening by high-frequency induction heating according to the ideal hardening pattern shown by the symbol A in FIG. The inner surface is also surface hardened using the ideal hardening pattern shown by reference numeral B in FIGS. 1 and 2 to increase the hardness of the inner and outer surfaces of the outer ring 1. However, in this type of universal joint, in order to maintain the joint's flexibility and rotational force transmission function, a large number of the joint balls 6 are provided between the socket portion 3 and the inner ring 5. Therefore, the inner surface of the socket part 3 is carved with grooves (ball fitting grooves) 7 into which these balls 6 fit properly. is held at a predetermined position between the socket portion 3 and the inner ring 5. Therefore, the socket part 3
As shown in Fig. 2, the wall thickness is thinner at the groove 7 portion and thicker at the rib 8 portion between the grooves 7 and 7, resulting in an extremely uneven flower shape as a whole. There is. Such outer ring 1
When high-frequency induction heating is applied to the inner surface of the socket 3, J
Compared to the wall thickness, the hardened layer is deep in the groove 7 part, but in the rib 8, the hardened layer is shallow compared to the wall thickness, resulting in unevenness as shown in Figure 6a. There is a tendency to form a hardened layer with a deep depth, and during cooling, the outer ring 1
Since both the turntable 9 and the gate are rotationally driven, the cooling water flows concentratedly into the groove 7, further aggravating the above-mentioned disadvantages, and as a result, the desired state as shown in FIGS. 1 and 2 is produced. Hardening pattern B cannot be obtained, and changes in the material structure occur over the entire inner layer of the socket 3, resulting in a decrease in product strength and resulting in poor heat treatment. In view of these problems, the present applicant has separately filed an application for a quenching method for uniformly heating the inner surface of a flower-shaped socket having such grooves. The present invention, when cooling the inner surface of the socket whose inner surface has been uniformly heated in this manner, uniformly contacts the entire inner surface of the socket with the cooling water to prevent uneven heating of the inner surface of the socket due to uneven cooling. It is intended to prevent Hereinafter, a specific embodiment of the present invention will be described based on FIG. A through hole 10 is drilled, and the socket portion 3 is passed through this through hole 10.
A surface-hardened coil body 11 for high-frequency induction heating is thrust inside.

Reference numeral 12 denotes a rod that supports this surface-hardened coil body 11, and this rod 12 has a water supply pipe 1 connected to a required water supply source.
3 is fitted over the water supply pipe 13, and the upper end of the water supply pipe 13 is extended to just above the surface-hardened coil body 11, and a large number of nozzles 14 are installed on the side surface of the upper end of the water supply pipe 13 (as shown in FIG. 4). are opened, and the cooling water is supplied into the socket 3 through the water supply pipe 13 and is spouted outward from the nozzles 14.

Reference numeral 15 denotes an umbrella-shaped rectifying plate fixed to the upper end of the water supply pipe 13. This rectifying plate 15 regulates the direction of the cooling water jetted from the nozzles 14, and directs the cooling water into the grooves. 7 and rib 8 parts. It works to spray uniformly and reliably on both sides with a predetermined jetting force.

Reference numeral 16 denotes a water storage cavity formed directly below the turntable 9. This cavity 16 is surrounded by a housing 17, and a housing 17, that is, a lower part of the cavity 16 is formed directly below the cavity 16. Open the open part in half. A water receiving plate 18 is provided for airtight closure.

In this embodiment, the heating coil body 11, the water supply pipe 13, the nozzle 14, etc. are formed into one body, but the present invention is not limited to this. Needless to say, it can also be applied.

Thus, when the socket part 3 of the outer ring 1 heated by the surface-hardened coil body 11 is rotated together with the turntable 9 by an external means (not shown), and the inner surface of the socket part 3 is cooled as required, water is supplied. Cooling water is supplied to the pipe 13, and the cooling water is directed outward (radially) from the upper end of the water supply pipe 13 to the entire circumference of the rectifier plate 15 through the aforementioned nozzle 14.
When the cooling water is ejected onto the inner surface of the socket 3, it hits the inner surface of the socket and flows down along the entire inner surface of the socket due to the force of the impact. The water is cooled, and then passes through the turntable through hole 10 to the water storage cavity 16, and from this cavity 16) the housing 17 and the water receiving plate 1 are
Water is naturally drained to the outside through the gap between the water supply pipe 8 and the water supply pipe 13 or around the water supply pipe 13. In other words, if you simply spray cooling water into the socket for cooling, since the socket is rotating, the cooling water that flows down only by its own weight along the inner surface of the socket will be affected by centrifugal force. Most of the water flows down through the grooves 7, and the amount of water flowing down along the ribs 8 is extremely small. Uniform cooling of the inner surface of the socket is not achieved, and due to this uneven cooling combined with the aforementioned heating unevenness, it becomes impossible to form a hardened layer of uniform depth on the inner surface of the socket. Furthermore, in the present invention, water storage space 1
The amount of cooling water supplied into the socket 3 from the water supply pipe 13 is made larger than the amount of cooling water drained to the outside from the water supply pipe 13.

If this is done, the cooling water will start to be stored in the water storage space 16 at the same time as the cooling starts, and the water level in the water storage space 16 will rise in a short period of time, and eventually the inside of the inlet part 3 and the water storage space will rise. The entire area inside the chamber 16 is filled with cooling water, and as a result, the cooling water is uniformly filled on every part of the inner surface of the socket 3 without being affected by the centrifugal force acting on the socket 3. Cooling water comes in contact with any part of the inner surface of the socket to provide uniform cooling. As described in detail above, the present invention includes placing the outer ring of a constant velocity universal joint with its socket facing downward, and inserting a high-frequency induction heating coil body into the socket by penetrating this support plate. , in which the inner surface of the socket part is surface hardened by the coil body, cooling water is forcibly and reliably sprayed along the entire circumference of the socket part after high-frequency heating to cool the inner surface of the socket part. By this cooling, a hardened layer of uniform depth can be formed regardless of the grooves and ribs on the inner surface of the socket. Moreover, the present invention provides a water storage chamber directly below the support plate that communicates with the inside of the socket, so that the amount of water supplied from the water supply pipe is larger than the amount of cooling water discharged from the water storage chamber, and the inside of the socket is increased. Since the cooling water is always kept in a full state, the cooling water contacts the inner surface of the socket evenly after a predetermined period of time after cooling begins, and the cooling effect is equal on all parts.
There is an advantage that the inner surface of the socket part is hardened to a uniform depth.

It goes without saying that the present invention can also be applied to the outer ring of a constant velocity universal joint, as typified by Japanese Patent Publication No. 44-22842, in which the inner ring can slide in the axial direction.

[Brief explanation of drawings]

1 and 2 are diagrams showing an ideal hardening pattern during surface hardening of the outer ring of a constant velocity universal joint, FIG. 3 is a longitudinal cross-sectional view of an apparatus for explaining the method of the present invention, and FIG. FIG. 3 is an enlarged sectional view of a main part, FIG. 5 is a sectional view showing an example of a constant velocity universal joint, and FIGS. 6A and 6B are schematic views showing a hardened layer. 1...Outer ring, 3...Socket part, 9...
... Support plate (turntable), 11 ... High frequency induction heating quenched coil body, 13 ... Water supply pipe,
16... Vacant room for water storage.

Claims (1)

[Claims] 1 A water supply pipe inserted into the socket in which the outer ring of a constant velocity universal joint is rotatably placed on a horizontal support plate with its socket facing downward, and the inner surface of the socket is hardened. An umbrella-shaped rectifier plate is provided at the opening of the support plate, and a water receiving plate is provided directly below the support plate to form a semi-enclosed water storage chamber that passes through the support plate and communicates with the inside of the socket. The cooling water is cooled by injecting water radially toward the inner circumferential surface of the socket part using the rectifier plate, and temporarily storing the cooling water in the socket part and the cavity using the water receiving plate. A method for hardening the inner surface of the socket of the outer ring of a constant velocity universal joint.