JPS599124A - Simultaneous hardening method of rack bar for steering - Google Patents

Abstract

PURPOSE:To harden simultaneously and efficiently the tooth face and rear face of a rack bar for steering, by constituting a titled device of a pair of unit conductors which face to each other to said faces, a pair of the 1st and the 2nd contact electrodes, the 1st and the 2nd proximity conductors, and a high frequency electric power source. CONSTITUTION:A titled device is constituted of a pair of unit conductors which consist of the 1st conductors 2, 2' and the 2nd conductors 3, 3' combined via an electrical insulator 18 and face respectively to the tooth face side 10 and rear face side 11 of a rack bar 9 for steering, a pair of the 1st contact electrodes 4, 4' connected respectively to the 1st conductors 2, 2', and a pair of the 2nd contact electrodes 5, 5' connected respectively to the 2nd conductors 3, 3'. The 1st and the 2nd proximity conductors 6, 7 are connected respectively to the 2nd conductors 3, 3', and many injection holes for cooling water for hardening are punched on the surfaces thereof facing to the face 10 and the face 11. Inflow pipes 62, 72 for cooling water are welded to the respective holes. A high frequency power source 8 is connected to the 1st, and the 2nd conductors 2, 2', 3, 3'.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for simultaneously hardening the tooth surface and back surface of a steering rack bar by high frequency direct current hardening.

Conventionally, the south and back surfaces of a steering rack bar were individually hardened. That is, the tooth surface was treated with a tooth surface hardening device, and the back surface was treated with a back hardening device using a two-rod method.

In such a quenching method, the workability and productivity are extremely low. Therefore, an object of the present invention is to provide a hardening device that can efficiently harden the front and rear surfaces of a rack bar at the same time in order to eliminate the above-mentioned drawbacks. The first conductor and the second conductor are combined to form a pair of reigning conductors, which are arranged and installed facing each other on the tooth side and back side of the steering rack bar, which is the object to be hardened, and the first conductor of each unit conductor. upper and lower first contact electrodes each connected to the conductor and disposed in contact with one end in the long side direction of the tooth surface and the back surface; a pair of upper and lower second contact electrodes arranged in contact with each other at the other end in the long side direction, and a first contact electrode and a second contact of the reporter unit conductor connected to either the first conductor or the second conductor; a first proximal conductor and a second proximal conductor each disposed between the electrodes in close proximity to the tooth surface and the back surface, and equipped with a cooling means capable of spouting cooling water onto the m-plane and the back surface; A hardening apparatus includes a high frequency power source to which a first conductor and a second conductor are connected.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

The hardening apparatus A according to this embodiment includes a first conductor 2 and a second conductor 3.
a pair of unit conductors 1.1', a pair of first contact electrodes 4, 4', and a pair of second contact electrodes 5.5'.
, a first proximal conductor 6 , a second proximal conductor 7 , and a high frequency power source 8 .

The unit conductors 1, 1' are formed by combining a short first conductor 2 and a long second conductor 37 with an electrical insulator 18 interposed therebetween, and are used for steering as a hardened body. They are arranged opposite to each other on the tooth surface 10 side and the back surface 11 side of the rack bar 9.

The four first contact electrodes on the tooth surface 10 side are electrically connected to the first conductor 2, and are disposed with their tips 4a in contact with one end of the tooth surface 10 of the rack bar 9. The five second contact electrodes on the tooth surface 10 side are connected to the end 31 of the elongated second conductor 3 on the opposite side to the part where it is combined with the first conductor 2, and are connected to the rack. The tip portion 5a is disposed in contact with the other end of the south surface 1o of the bar 9.

Meanwhile, the back above! The first contact electrode 4' on the i side is electrically connected to the upper conductor 2', and is shown in FIG.
As shown in FIG. 2, which is an X-ray cross-sectional view, the rack bar 9 is placed in contact with the rear surface 11 of the rack bar 9 so as to support the rear surface 11 of the rack bar 9.

Further, the second contact electrode 5' on the rear surface 11 side faces the second contact electrode wL5 on the tooth surface 10 side, and is connected to the second conductor 3'.
It is connected to the end portion 31' of the rack bar 9, and is placed in contact with the other end of the back surface 11 of the rack bar 9 in a manner that supports it, similarly to the first contact electrode 4'.

Note that the pair of first contact electrodes 4, 4' and the pair of second contact electrodes 4, 4'
The contact electrodes 5, 5' are fixed to the -1-first conductor 2.2' and the second conductor 3.3', respectively, with screws 12 or the like.

↑・The writing 1 and the 2nd adjacent conductor 6.7 are shown in Fig. 1 and 1.
As shown in FIG. 3, which is a sectional view taken along the line Y-Y in the figure, it is formed of a copper plate into a hollow box shape corresponding to the shape and dimension of the tooth surface 10 and back surface 11 of the rack bar 9, and the tooth surface ■0. and back 1
Opposed to 1 are quenching cooling water injection holes 61 and 7, respectively.
), and quenching cooling water inlet holes (eaves 62, 72) are welded to the side surfaces of each tube.

The first proximal conductor 6 and the second proximate conductor 7 are each connected to the second conductor 3
and the second conductor 3', and each has a cooling water injection hole 6.
1 and 71 are disposed facing each other in close proximity to the tooth surface IO and the back surface 11 of the rack bar 9.

Note that 1.3 and 13 are fluid pressure cylinders, which are designed to ensure reliable contact between the rack bar 9 and the pair of first contact electrodes 4.4' and second contact electrodes 5, 5'. It is disposed so as to press down on the second conductor 3 of the portion from above.

Further, in the high frequency power source 8, connection lines from the power source 8 are branched in the middle, and connected to the pair of first conductors 2, 2' and second conductors 3, 3'.

Next, the operation of this embodiment will be explained.

After setting (correcting) the steering rack bar 9 to the above-mentioned predetermined position, when a high-frequency current is applied from the high-frequency power source 8, the high-frequency current i! flows from the first conductor 2°2' to the first contact electrode 4.
, 4' to the tooth surface 10 and back surface 11 of the rack bar 9,
Through the second contact electrodes 5, 5', the second conductors 3, 3', the first
And through the surfaces of the second adjacent conductors 6 and 70, it flows again from the second conductors 3, 3' to the high frequency power source 8, or alternatively flows in the opposite path.

Here, the current flowing from the high frequency power source 8 is ``Ai'', the current after branching is ``Ai'', the current after branching is ``Ai'', the current flowing to the tooth surface 0 and the back surface 11 is ``Ai'', and the return current from the contact electrodes 5 and 5' is ``Ai''. !/
i+2, and the current after branching is i.

The current flowing along the tooth surface 10 and back surface 11 of the rack bar 9 is '+' and the current flowing in the first and second adjacent conductors 6 and 7 is %12, so that the generated magnetic flux is minimum (circuit impedance is minimum). The current density is distributed so that it flows closely to phase q.

Still, the tooth surface 10 and the back surface 11 of the rack bar 9 and the first and second adjacent conductors 6 and 7 each form one coil, and an induced current also flows through the tooth surface 10 and the back surface 11.

4, 5, and 6 show partially enlarged sectional views of the tooth surface 10 of the rack bar 9, the first proximate conductor, the rear surface II, and the second proximal conductor, and the flow of current.

In Fig. 4, the induced eddy current %i (induced eddy current %i) is generated mostly at the tooth tip due to the tip effect of the induced current (magnetic flux concentrates on the convex part and a large amount of thin current flows there)7, and the induced eddy current is generated directly at the tooth tip. Current Q
A composite current number i'' of j7 and eddy current %i flows.

Due to the tip effect and proximity effect, which are characteristics of high-frequency current, the current density on the tooth is high at the tooth tip and low at the tooth bottom, and the convexities of the tooth are uniformly heated and the tooth bottom is heated thinly.

In the back part shown in FIG. 5, there is an induction thin electric current.

Flow! A composite current period of A11 and direct current 3AI2 flows, and the workpiece is heated uniformly.

When the tooth surface 10 and back surface 11 reach a predetermined degree of quenching, the high frequency power source 8 is closed and quenching cooling water is injected from the injection holes 61 and 71 of the adjacent conductors 6 and 7 to rapidly cool the tooth surface and back surface. Then, the required hardened layer can be obtained.

Figure 7 shows the steering rack bar shown in figure fPj1.
FIG. 8 shows a pattern of the hardened layer T when FIG. 7 is cut along the line WW.

As explained in detail below, the quenching process of the above structure according to the present invention
By using the tε position, the steering rack bar
The tooth surface and back surface of the tooth surface can be hardened efficiently at the same time, and work efficiency is significantly improved compared to hardening using conventional equipment, contributing to shortening of working time and cost reduction. I can do it.

[Brief explanation of drawings]

FIG. 1 is a conceptual diagram showing an embodiment of the quenching apparatus according to the present invention, and FIGS. 2 and 3 are X-X lines and Y-Y lines in FIG. 1, respectively.
Line sectional view, Figure 4 is a conceptual diagram showing the flow of current on the tooth surface side, Figure 5 is a conceptual diagram showing the flow of current on the back side, and Figure 6 is a diagram showing the flow of current on the tooth side.
7 and 8 are cross-sectional views showing the butter/hardened layer of the rack bar after quenching, and FIG. 8 is a cross-sectional view taken along the line w-W in FIG. 7. shows. A... Quenching device, 1... Unit conductor, 2.2'... First conductor, 3.3'...
...Second conductor, 4.4'...First contact electrode, 5.5'...Second contact electrode, 6...First proximity conductor, 7. ...Second adjacent conductor, 8...High frequency power supply, 9...Steering rack bar 110...
・・・Tooth surface, 11・Curve・Back surface. Procedural amendment (voluntary) September 9, 1980 Kazuo Wakasugi, Commissioner of the Patent Office ■, Indication of the case 1982 Patent Application No. 119286 2,
Name of the invention: Simultaneous hardening device for steering rack bars 3, Relationship with the case of the person making the amendment Patent applicant address Name: Denki Kogyo Co., Ltd. (Name) Contents of the amendment (1) Page 7, line 20 of the specification 1 induced eddy current%
Correct B J to [induced eddy current y 11; (2) Direct current %i2J in lines 3 and 10 on page 8 of the specification is corrected to direct current 3('l). (3) Lines 3 and 9 on page 8 of the specification 1st from row
The 0th line [eddy current y2i1J is [eddy current 3Ai”,
”. (4) "Synthetic current outside i'' and [synthetic current 3A+J" in lines 3 to 4 and 10 of page 8 of the specification
# Correct j to [composite current %i7J. (5) "Figure 1, Figure 5" in line 9 of page 8 of the specification is corrected to "Figures 5 and 6." (6) In the 13th line of page 8 of the specification, "close" should be amended to "open and 1." (7) Among the drawings, Fig. 1 and Fig. 6 should be amended as separate sheets. .

Claims (1)

[Claims] Steering rack bar made by high frequency direct current hardening
In a device for hardening the tooth surface and back surface of a steering rack bar, a first conductor and a second conductor are combined via an electrical insulator, and the conductor is hardened to face the tooth surface side and back surface of a steering rack bar, which is the object to be hardened. a pair of unit conductors disposed; a pair of first contact electrodes under 1L each connected to the first conductor of each unit conductor and disposed in contact with one end in the long side direction of the south face and the back face;
A pair of upper and lower second conductors each connected to the second conductor of each of the unit conductors and arranged in contact with the other end in the long side direction of the tooth surface and the back surface.
A contact electrode, connected to either the first conductor or the second conductor, and disposed between the first contact electrode and the second contact electrode of each unit conductor in proximity to the south face and back face, and A first proximate conductor and a second proximate conductor each having a cooling means capable of spouting cooling water onto the tooth surface and back surface, and a high frequency power source to which the pair of first conductor and second conductor are connected. Simultaneous hardening equipment for steering rack bars.