JPS6226440Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an induction hardening device for a steering rack of a rack and pinion type steering device for an automobile.

As shown in FIG. 2, this type of induction hardening apparatus for steering racks includes electrodes 4, which are in contact with both ends 3, 3 of the rack teeth 2 of the steering rack 1;
The steering rack 1 is clamped and fixed by the electrodes 4 and holding members 5, 5 located opposite to the electrodes 4, 4. In this way, since the rack teeth 2 of the steering rack are in a restrained state, the rack teeth 2 thermally expand when heated, but the thermal expansion is restrained at the clamping and fixing position, and the restrained heat is Due to the influence of expansion, the distortion of the rack tooth portion 2 becomes complicated and large, making correction work after hardening difficult, resulting in poor work efficiency and increased manufacturing costs.

Moreover, in order to reduce the distortion of the rack tooth portion 2,
When the pressing force of the holding members 5, 5 is adjusted to be low to relieve the restraint on thermal expansion of the rack teeth 2,
Sufficient contact pressure between the steering rack and the electrodes cannot be ensured, and the electrodes tend to spark, shortening the life of the electrodes.

An object of the present invention is to provide a steering rack induction hardening device that can reduce distortion during hardening without lowering the contact pressure between the steering rack and the electrode.

An embodiment of the present invention will be described below with reference to FIG.

A conductor 10 is placed above the conductor 8 via an electrical insulator 9.
are arranged in parallel, and a rectangular parallelepiped-shaped induction coil 13 facing the rack teeth 12 of the steering rack 11 is fixed above the conductor 8.
One electrode 15 is connected to the screw 17 adjacent to both ends of the electrode 3.
The other electrode 19 is also fixed in the same manner as the electrode 15, and arcuate grooves 16, 20 are provided in the contact portions of these electrodes 15, 19 with the rack teeth. , roller-like rolling elements 14 and 18 are swingably mounted in this groove, and these electrodes 15 and 1
Both ends 21 and 22 of the rack teeth 12 of the steering rack 11 are brought into contact with the rolling elements 14 and 18 of 9, and the rack teeth 12 and the induction coil 1
3 and facing each other at a predetermined distance t,
The steering rack 11 is securely fixed at a predetermined position by the holding members 23 and 24 fixed to the reciprocating shafts of the hydraulic cylinders located opposite to each other at the ends 21 and 22 of the rack teeth 12 and the electrode 1.
A high frequency power source 25 is connected to the conductor 8 and the conductor 10 to form a loop circuit, and a high frequency current from the high frequency power source 25 is applied to the electrodes 15, 19 and the induction coil 13. supply. Further, a cooling liquid supply device 27 is provided for supplying a cooling liquid such as water into the induction coil 13 so that the cooling liquid such as water is ejected from the small hole 26 from the opposing surface of the induction coil 13 after heating the rack tooth portion. .

In this way, since rolling elements are provided at the contact parts that contact both ends of the rack teeth of the electrode, when the rack teeth expand thermally and try to warp during heating, the rolling elements of the electrode swing and follow this warping. However, the thermal expansion of the rack teeth is not restricted, and distortion is reduced.

Since the device of the present invention is provided with rolling elements at the contact portions that contact both ends of the rack teeth of the steering rack, the pressing force at the clamping and fixing position of the rack teeth of the steering rack is not reduced. It is possible to relieve the restraint state with a high pressing force and reduce the distortion of the rack teeth due to thermal expansion.
Straightening work after quenching becomes easier, work efficiency can be improved, and manufacturing costs can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view of an embodiment of the present invention, and FIG. 2 is a partially cutaway front view of a conventional example. Explanation of symbols: 1, 11... Steering rack, 2, 12... Rack teeth, 4, 4... Electrode,
5, 5... Fluid pressure cylinder, 7... High frequency power supply, 13... Induction coil, 15, 19... Electrode,
14, 18...Rolling element, 16, 20...Circular groove,
23, 24... Holding member, 25... High frequency power supply,
27...Cooling liquid supply device.

Claims (1)

[Scope of utility model registration request] an induction coil facing the rack teeth of the steering rack; electrodes adjacent to both ends of the induction coil and in contact with both ends of the rack teeth; a holding member located opposite the electrode; and the electrode and the induction coil. a high-frequency power supply that supplies high-frequency current to the coil;
The steering rack induction hardening device has a cooling liquid supply device for supplying cooling liquid into the induction coil, and is characterized in that rolling elements are provided at contact portions that contact both ends of the rack tooth portion of the electrode. Induction hardening equipment for steering racks.