JPS6056476A - Build-up welding method of wheel - Google Patents

Abstract

PURPOSE:To increase the efficiency of working and to eliminate damage of shafts and bearings by repairing the tread of a wheel by building up while cooling the bearing of the wheel and cooling the built-up part slowly to normal temperature. CONSTITUTION:A wheel 10 taken out from a vehicle is lathed, and the tread (a) is machined roughly. A cooling case 13 is attached to a bearing 12 fitted to the shaft, and the bearing 12 is cooled to below 120 deg.C by sending air from a blast pipe 14. After preheating the wheel 10 by a preheater C while rotating the wheel, repairing (b) by build-up welding is executed. Then, the temperature of the wheel 10 is made uniformly by after-heating (d). The wheel is then housed in a slow cooling box 15, and air is sent to the cooling case of the bearing 12. At the same time, a heat retaining box 16 is attached to the wheel 10 and cooled slowly to normal temperature. After cooling, the tread (a) is finished by the lathe 11.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention improves work efficiency by not attaching or detaching wheel bearings, and
The present invention relates to an improvement in wheel build-up welding that prevents bearing damage and non-tightening due to attachment and detachment, and extends the life of the bearing.

(Prior art) In conventional wheel build-up welding, the wheel is first heated evenly to prevent distortion and cracks, and after completion, it is gradually cooled down to room temperature in a slow cooling box. During this work process, the humidity rises to about 400C, so the temperature of the bearing installed in the wheel also rises, exceeding the normal limit temperature of 120'C'z, making it unusable, so the bearing is removed and cooled. It is common that all the parts are installed afterwards.

However, with this conventional technology, it takes time to install and remove the bearing, and when the bearing is removed, galling may occur in the inner race of the bearing or the axle, and the tightness of the inner race may be lost. There was a drawback that approximately % of the batteries were rendered unusable.

(Object of the Invention) The present invention eliminates all of the various drawbacks mentioned above and proposes a method for overlaying a wheel, which is carried out with the bearing fitted onto the shaft.

(Structure and operation of the invention) The gist of the present invention is that when repairing a worn wheel tread surface by overlaying welding, the entire cooling case is attached to the outer bearing of the wheel, and the entire cooling medium is introduced to cool the entire bearing to 120C or less. A wheel overlay welding method carried out with a bearing fitted to a shaft, which is characterized by performing overlay repair on the wheel tread, and after completion of the overlay repair, the overlay part is slowly cooled to room temperature in an annealing box. It is.

The significance of carrying out the present invention in this manner is that the L/
There is a bearing part in the bearing part, and when the wheel tread surface is repaired by welding, the amount of heat is transferred directly to the bearing part and becomes high temperature.To avoid this, a cooling case is installed on the bearing part, and cooling is carried out in the meantime. Introducing a medium and repairing the wheel tread while cooling the bearing part to 120C or less so as not to reduce its function, and then rapidly cooling it after the completion of the repair will cause undesirable situations such as cracks in the built-up part. Since this occurs, it is placed in a slow cooling box and slowly cooled to room temperature, making it possible to maintain the overlay repaired area in a healthy state.

The cooling case is not particularly limited as long as it covers the entire bearing group, but it is usually made of thin steel plate into a full cylinder shape, which is advantageous in terms of cost. I can do it. Although there are no particular limitations on the cooling medium, the cooling medium below the bearing portion 120C can be easily realized by spraying normal air at 7000 cm3/cm' over the bearing part 120C.

If the slow cooling in the slow cooling box is about 1.3 tT/min or less, the normal overlay repaired part is sound.

The present invention will be explained in detail below based on Examples.

Figure 1 shows the work process. (■) The wheel 10 removed from the vehicle is placed on a lathe 11, and the tread a is rough-cut to ensure uniform welding. (■) is when the rough-cutting is completed. The wheel 10 is attached to a welding turntable (not shown),
At this time, in order to cope with the high temperature after the next process, the bearing 12
After cooling case 13 is fully installed, air blowing starts and bearing 12 is installed.
Maintain the temperature within 80℃.

(3) Preheating was carried out in preheater C for about 1 hour while rotating the wheel 10 times on a welding turntable, and the wheel temperature was raised to 250C.
All measures are taken to prevent distortion and cracks during welding. (2) performs build-up welding repair (b2) on the wheel 10 whose temperature has risen, and (2) performs heating d to equalize the temperature of the wheel 10 after welding is completed. When the temperature becomes even, stop the rotation and interrupt the ventilation.2. Remove the air pipe 14.

(2) Stores the wheels 10 in the slow cooling box 15, attaches the air pipe 22 to the cooling case 13 on the bearing 12, and restarts air blowing. On the other hand, the wheels 10 are attached to the heat insulating box 16'ff, and the lid is completely attached to the slow cooling box 15. As a result, the bearing 12 is maintained at 60C, and the wheel 10 falls within the allowable temperature drop of 80C/hour (1st hour = 70C, 12th hour - 50C, 13th hour = 40C, hereinafter 30C), and reaches room temperature in about 10 hours. (2) is completed by finishing the tread surface of the wheel IO taken out from the slow cooling box 15 using a lathe 1.

However, in this work process, the present invention does not remove the bearing 12 in step (2), but installs the cooling case 13, and the entire process is carried out with the bearing 12 attached, and the cooling box 15 in step (2) is modified, and the cooling case 13 is installed. This is to prevent rapid cooling of the wheel 10 by carrying out double heat retention using a heat insulating box 16 for keeping the wheel 10 heated by exposing the 12 parts to the outside.

FIG. 2(a) is a sectional view of the cooling case 13, FIG.
is a side view of arrow a in FIG. Indicates a hole.

Figure 3 (al is a sectional view of the blind center 17, which is attached to the welding rotary table from the outside of the cooling case 13 of the vehicle 18, Figure 3 (1)) is a cross-sectional view of the blind center 17. FIG. 21 indicates a tightening bolt hole.

FIG. 4 shows how the cooling case shown in FIG. 3 is installed. The procedure is to first remove the front cover and axle box of the bearing, and then remove the back cover 19.
Leave the axle box mounting bolt 20 on its side, and attach this bolt 20 to the J of the cooling case 13. Insert it according to the root hole,
Tighten together with the back cover 19.

Next, the blind center 17 is attached to the full force axis 18, and the built-in air pipe 21 is attached to the welding rotary table to complete preparations. 31 is an inner lace.

FIG. 5 (al is a heat insulating box 16 used in the slow cooling box 15, FIG. 5 (bl is a side view of FIG. 5(a).
The figure shows how it is assembled and in order to prevent heat radiation from the contact points between the upper and lower boxes 16-1 and 16-2 and the axle 18, the upper and lower boxes 16-1, 16-2 and the axle 18 are fastened together with a heat shield plate 2f glued with a heat insulating material 30 (t = 32 mm). It shows the situation.

As described above, this invention has a simple structure, is easy to install and operate, and is also characterized by the fact that it can be easily implemented by using existing equipment and making additional modifications.

(Effects of the invention) The effects of this invention are that work efficiency is significantly improved by eliminating the need for attachment and detachment of bearings during welding, and that damage to axles and bearings is completely eliminated due to the elimination of attachment and detachment of bearings. In addition to extending its lifespan, we have also eliminated the need for repairs such as galling.

Comparing this with the conventional method, the first step is to remove the nuts from the axle box mounting bolts on the bearing, and then remove the front cover and the axle box entirely. The bearings exposed through this work are extracted using respective extraction jigs, and bearings damaged during this work are discarded, and if galling occurs on the axle, the axle is repaired for reuse. The part where galling occurs is ground with a lathe to remove all the galling, and after overlaying is done by overlay welding, the part is ground and finished with a lathe to a diameter within tolerance.

In addition, in preparation for reuse of successfully removed bearings, measure the diameters of the axle and bearing inner race, check to see if there is any interference within tolerance, and discard bearings without interference.

All bearings discarded during the above work process were replaced with new ones.

The causes of axle repair, replenishment due to bearing damage, etc. that occur during this conventional process are all caused by removing all the bearings, and since this extraction work is not performed in the present invention, all repairs and replenishment are required. This eliminates the need for bearing installation work in the post-process, and the effect is incredible.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram of the method according to the present invention, Figure 2 (al is a sectional view of the cooling case according to the present invention, Figure 2 (bl is a side view thereof, and Figure 3 (al is a welding rotary table according to the present invention). Fig. 3 is a cross-sectional view of the blind center for mounting the axle, Fig. 3 is a side view thereof, Fig. 4 is an explanatory diagram of the assembly of the axle/wheel and the cooling case/blind center, Fig. 5 (al is the heat retention according to the present invention) Fig. 5 (1)) is a front view of the box, Fig. 6 is a side view thereof, and Fig. 6 is an explanatory diagram of the installation of the heat insulation box. 10...Wheel 12...Bearing 13...Cooling case 15. ... slow cooling box 16 ... heat retention box 17 ...
・Blind center 18...Axle 19...Back cover 21...Blow pipe perforation 1 (+) (2) (υ 1 (4) <5) (t,) (q) 2nd perforation (α )(btsu0 Figure 3 (ku) (btsuFigure 4Figure 5Figure 6/f, -/ 6-2

Claims (1)

[Claims] When repairing worn wheel treads by welding overlay, a cooling case is attached to the outer bearing part of the wheel with the bearing fitted to the shaft, and a cooling medium is introduced to cool the whole bearing part to 120C or less while the wheel tread is being repaired. A wheel overlay welding method, which is characterized in that the overlay repair is carried out, and after completion of the overlay repair, the overlay part is slowly cooled to room temperature in an annealing box.