JPS5980723A - White pig iron hardening device for sliding surface of cam - Google Patents

Abstract

PURPOSE:To increase the effective width of the sliding surface of a cam in a white pig iron hardening device for a sliding surface which heats and melts the sliding surface by a torch by pressing a backing strap to the angle part formed of the sliding surface and the side face of the cam from the side face and changing the shape of the angle part. CONSTITUTION:A cam 4 mounted with a backing strip 10 thereon after preheating of the cam 4 is so positioned that the sliding surface B-C at a juncture 7 is held horizontal. An electrode 8 of a torch 1 is placed opposite to the point A of the cam 4. The sliding surface is then heated and melted by connecting the electrode 8 and the cam 4 to a power source, running cooling water in the cooling water passage 13 of the plate 10, ejecting inert gas from a nozzle 9 and maintaining the electrode 8 at a negative potential. At the same time, a motor 2 is driven to move or stop properly the torch 1 by means of a driving device 3. Since the plate 10 is in contact with an angle part 12 in this white pig iron hardening device, the part 12 maintains the initial shape without changing even if the sliding surface is melted.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a device for forming a white pig iron hardening layer on a cam sliding surface. It is characterized by having an abutment plate that comes into contact with the corner formed by the cam sliding surface and the cam side surface from the side surface of the cam. Therefore, since the contact plate is in contact with the corner, when the cam sliding surface is heated and melted by a torch, the corner does not flow out to the side of the cam, so the shape of the corner of the cam sliding surface is There is no change (the effective width of the cam sliding surface can be made sufficiently large).

Two embodiments of the present invention will be specifically described below.

In the first embodiment shown in FIGS. 1 to 4, the torch is moved horizontally (left and right in FIG. 1) by a drive device B driven by a motor 2 as shown in FIG. A reciprocating motion is made in the direction perpendicular to the plane of the paper by an oscillator that does not move. A cam 4 for an internal combustion engine is installed inside the base 5. The eccentric interior 6. has a different center of curvature from the foundation interior 5 and has a smaller diameter than the foundation interior 5. and connection parts 7 and 7' that smoothly connect the foundation interior 5 and the eccentric interior 6.
The portions A-B and E-F connected to the string foundation interior 5 are curved, and the portion B is connected to the eccentric interior 6.

-C and DE are formed into substantially straight lines. torch 1
As shown in FIG. 4, it has a tungsten electrode 8 and a gas nozzle 9 provided so as to cover the tungsten electrode 8. The contact plate 10 is attached to both sides 11 of the cam 4 with A-
A corner portion 1 formed by the sliding surface of the cam 40 and the side surface is disposed so that the upper end is in contact with the cam 40 in a range F as shown in FIG.
It extends above 2. And this plate 10
is made of metal and has a cooling water passage 13 inside.

First, as a preliminary step, the cam 4 with a thickness of 13 m is
0'CK preheat.

Next, as a first step, the cam 4 is fitted with the contact plate 10 as shown in FIG.
Position C so that it is horizontal, and the electrode 8 of the torch 1 faces the point A of the cam 4. At this time, the distance between the electrode 8 and the sliding surface of the cam 4 is 2.5 sui when the electrode 8 faces between B and C of the cam 4, and the distance between the electrode 8 and the sliding surface of the cam 4 is 2.5 sui. It is set perpendicular to the sliding surface. Further, the electrode 8 and the cam 4 are connected to a power source (not shown), and the cooling water passage 1 of the backing plate 10 is connected to a cooling water supply device.

Subsequently, as a second step, as shown in FIG. 4, argon gas is ejected from the gas nozzle 9 at a rate of 811/MIN, and the electrode 8 is set to a negative potential, and a current of 11 OA is supplied between the electrode 8 and the cam 4. Then electrode 8 and cam 4
An arc is generated between the two and the sliding surface of the cam 4 is heated and melted into a circular shape with a diameter of about four groups.

At the same time, by driving the motor 2, the torch 1 having the electrode 8 is horizontally moved from AC to the right in FIG. At this time,
At the same time, the torch 1 is vibrated by an oscillator in the direction perpendicular to the plane of the first drawing at a period of 80 times/MIN and an amplitude of 6 +u+. Therefore, the electrode 8 snakes around while melting the sliding surface into a circular shape with a diameter of approximately 4 IIK and moves from A to C on the sliding surface of the cam 4, and the sliding surface from A to C is shown in FIG. The entire width 131I is heated and melted as shown in FIG.

Next, when the electrode 8 reaches the position facing the zero point, only the movement of the torch 1 by the drive device 6 is stopped as a third step, and at the same time as this stop, the cam 4 is moved inside the eccentric interior 6 as shown in FIG. The outer circumference is 100M/M with the center of curvature as the central axis.
The torch 1 rotates at a circumferential speed of IN, and as in the second step, the electrode 8 of the torch 1 forms a relatively circular heating melting point with a diameter of about 4 mm on the sliding surface while heating the torch at a rate of 100 mg/MIN.
Move at a frequency of 80 times/MIN and an amplitude of 611I, from C to D
The sliding surface is heated and melted over its entire width.

Next, when the electrode 8 reaches a position opposite to point D,
As a fourth step, as shown in FIG. 6, the cam 4 is stopped so as to be horizontal between D and E of the connecting portion 7'. At the same time, the motor 2 operates the drive device 3 to torch the torch 1.
is moved to FIG. 6D-)F at 100111/MIN. Then, the electrode 8 vibrates at a frequency of 80 times/as in the second step.
MIN, 100 xi while vibrating with amplitude 6 Ilm
Move to the right in Figure 5 at a speed of /MIN, and move cam 4 D-F.
The sliding surface in between is heated and melted over a width of approximately 13 m at the center.

Therefore, the sliding surface between A and F of the cam 4 is heated and melted.

Next, in the fifth step, the torch 1 is returned to the initial position shown in FIG. 1 and the contact plate 10 is removed from the cam 4.

Further, the cam 4 is naturally cooled (cooled in the atmosphere) to 100° C., and then water-cooled. As a result, the sliding surface between the cams 40A and 40F is baked, and as shown in Figure 4, a chill layer α with an arcuate cross section and a depth of about 2 mm at the deepest part and a martensite layer β are formed around it. .

In addition, in the case of a cam for an internal combustion engine, the cam does not work inside the base of the cam, so F-)A at cam 4.
There is no need to form a chill layer α on the sliding surface between the two.

Therefore, since the contact plate 10 is in contact with the corner 12 of the cam 4, even if the cam sliding surface is melted by the arc, the corner 12
Since the shape of 2 does not change, the cam sliding surface is formed parallel to the cam axis, and the rocker arm of the internal combustion engine comes into contact with the entire width of the cam sliding surface.

The load from one cam per unit area of the cam sliding surface is reduced, and the durability of the cam is improved.

Note that the above-mentioned backing plate 10 may be made of a high melting point metal, ceramics, etc. that does not react with molten cast iron. At this time, the cooling water passage 16
is unnecessary.

Further, although TIG was used for the torch 1 in the above embodiment, a laser, electron beam, plasma, etc. may be used.

Further, in the above embodiment, the contact plates 10 are provided on both sides, but they may be provided on only one side.

The second embodiment shown in FIG. 5 is a contact plate 10 in the first embodiment.
is supported by the torch 1 so as to automatically come into contact with both sides of the cam 4. Components common to those in the first embodiment will be described with the same reference numerals.

In FIG. 5, the torch 1 is attached to a drive device 6 and moves in a direction perpendicular to the plane of the paper. The stays 20 and 21 are supported by the drive device 6 and have air cylinders 23 and 24 attached to their lower ends. The contact plates 10', 10'' are made of ceramic and are formed into fan-shaped plates, and are located only in the vicinity of the torch 1 on the cam sliding surface, and are fixed to the operating rods of the F cylinders 23, 24.

The cam 4 is then pushed up by the lifting device from below in FIG. 5, reaches the position shown in FIG. 5, and is attached to the oscillator. Next, the air cylinder 23.24 force (extension is activated and the contact plate 1
0' and 10'' are brought into contact with both sides of the cam 40. At this time, the upper ends of the contact plates 10' and 10'' have reached the corner 12.

Next, as in the first embodiment, the cam 4 is vibrated in the left-right direction in FIG. Harden the sliding surface with white pig iron.

By the way, our plates io', io'' are on stay 20.
21, the torch 1 moves relative to the cam sliding surface and also slides on the side surface of the cam 4.

In addition, the contact plates 10' and 10'' are equipped with air cylinders 23.2
Since the air pressure inside the air cylinders 23 and 24 is low, when the cam 4 is vibrating in the left-right direction in FIG. 5 by the oscillator, the air is compressed and expanded by the cam 4. This prevents the vibration of the cam 4 from being transmitted to the stays 20 and 21.

Then, when the sliding surface of cam 4 from A to F is hardened with white pig iron, air cylinder 2! ,,24 contract, and the contact plate 10',1
0'' is released from the cam 4, and the cam 4 is lowered by a device consisting of an oscillator and allowed to cool naturally.

Therefore, the contact plates 10', 10'' move together with the torch 1 and come into contact with the corner 12 of the melting part near the torch 1, so there is no deformation (deformation) of the corner 12. That is,
Since the cam sliding surface melted by the torch 1 is immediately cooled by the atmosphere and by the cam itself, the deformation described above can be prevented by only contacting the contact plates 10' and 10'' for a short period of time after being melted by the torch 1. It is something that

In addition, the size and shape of the backing plates 10' and 10'' are optimal as appropriate.
Select the one with 4°0.

In addition, in the above embodiment, the contact plates 10" and 10" are the fifth
As shown in the figure, it was brought into contact with the side surface of the cam 4.

The upper ends of the contact plates 10', 10'' are tilted in the direction of the torch 1, and the contact plates 10', 10'' are tilted and formed so as to contact the corners 12 of the cam 4, and the air cylinders 23°2
The contact plates 10' and 10'' are supported on the stays 20 and 21 via springs.

When the cam 4 is raised from below, the corner portion 12 of the cam 4 may come into contact with the contact plates 10', 10'', and the vibrations caused by the oscillator of the cam 4 may be absorbed by the spring. However, since the torch 1 is blocked by the upper ends of the contact plates 10' and 10'' and cannot reach the corner 12, when the torch 1 reaches both ends in the cam width direction, the cam slides. It is necessary to control the output current to the torch 1, the moving speed of the torch 1 relative to the cam 4, etc. so as to melt the surface to a large extent.

[Brief explanation of drawings]

FIG. 1 is a front view showing a first embodiment of the present invention, FIG. 2 is an explanatory diagram showing a different operating state from FIG. 1, and FIG. 6 is an explanatory diagram showing a further different operating state from FIG. 1. , FIG. 4 is an enlarged sectional view of the main part of the first embodiment. No. 1 Hi No. 2. Senjaku 3 figure 4

Claims (1)

[Claims] A white pig iron hardening device for a cam sliding surface in which the cam sliding surface is heated and melted with a torch, characterized by having a contact plate that abuts from the side surface of the cam on a corner formed by the cam sliding surface and the cam side surface. White pig iron hardening device for cam sliding surface