JPS59215286A - Pressure welding method of composite material - Google Patents

Abstract

PURPOSE:To make the reduction of area of respective strips different and to provide a difference in the degree of work hardening in roll pressure welding of a composite material by winding the 1st strip on a roll, rolling the same together with the 2nd strip and rotating the pressure-welding rolls at different circumferential speeds. CONSTITUTION:The 1st strip 1 is wound on a small-diameter upper roll 5 and is pressure-welded and rolled together with the 2nd strip 2 between said roll and a large-diameter lower roll 6. The number of revolutions of the rolls in this case is the same, but the reduction of area of the strip 1 on the roll 5 is increased and the strips are satisfactorily pressure-welded without slipping at winding. Such change in the circumferential speed occuring in a difference in the roll diameters is also applicable to the conventional rolling mill by changing the number of revolutions of the upper and lower rolls. The method is applicable to production of a composite material for a backing metal having low hardness or a composite material for a thick backing metal.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of press-welding a composite material by pressing a first strip and a second strip together.

In conventional pressure welding, a pair of strips are inserted in an overlapping state between a pair of pressure rolls that rotate in opposite directions at the same circumferential speed, and the pressure welding force by the pair of pressure rolls is to join both strips together. However, in this pressure welding method, the rolling reduction rate of each strip is primarily determined depending on the diameter of each pressure roll, that is, depending on the load per unit area for each strip. In order to adjust the ratio, it is necessary to change the diameter ratio of the pressure roll, which is a complicated process.

In view of these points, the present invention provides a composite material pressure welding method that allows the downstream ratio of each slip to be controlled by simply changing the circumferential speed of the pressure roll without replacing the pressure roll. It is something to do.

The invention will now be explained with reference to the illustrated embodiment. In FIG. The second strip 2 is supplied directly from the supply reel 4 to the gap G between the pair of pressure rolls 5.6. .

-■- The second strip 2 is arranged so that it can be supplied to the take-up reel 8 without being wound around the pressure roll 6, that is, it is conveyed almost in a straight line from the supply reel 4 to the take-up reel 8. This allows the second strip 2 to be thick and to be easily used for pressure welding even if it is difficult to curve like the first strip 1. The first strip 1 and the second strip 2 are pressed together by a pair of pressing rolls 5.6 to form a composite material 7, and this composite material 7 is rolled onto a take-up reel 8.
I am trying to wind it up by.

In the illustrated embodiment, the pair of pressure rolls 5.6 labeled L are arranged so that the pressure roll 5 on the side of the first strip 1 is connected to the pressure roll 5 on the side of the second strip 2.
The diameters of the pressure rolls 6 on the sides are set large, and they can be forcibly driven by the same drive source 9 in opposite directions at the same rotation speed. In this way, when the diameter of one of the pressure rolls 6 is increased, the circumferential speed of the second pressure roll 5.6 can be made different even if the number of rotations of the second pressure roll 5.6 is kept the same. Pressure roll 6
The circumferential speed on the side becomes larger than the circumferential speed on the first pressure roll 5 side.

Then, tension is applied to the il strip L, the second strip 2, and the composite material 7 by a conventionally known appropriate method (not shown), and in particular, the first strip 1 is wound around the first pressure roll 5 with a required winding force. By this, even if the circumferential speeds of the first pressure roll 5 and the second pressure roll 6 are different, the distance between each pressure roll 5.6 and the first strip 1 and the second strip 2 is substantially the same. Care has been taken to prevent slipping.

Next, the effects of the present invention will be explained based on experimental results. Figure 2 shows four types of diameter ratios (hereinafter referred to as trol ratios) of a pair of press rolls 5.6 selected, and various ratios of circumferential speeds (hereinafter referred to as circumferential speed ratios) for each set of press rolls. Fig. 3 shows the results of measuring the rolling reduction ratios of the first strip 1 and the second strip 2 in the composite material 7 obtained at different times. This shows the results of hardness measurements.

In this experiment, an aluminum bearing alloy with a thickness of 1.40 mm was used as the first strip 1, and a 5 pcc-s steel plate with a thickness of 1.38 mm, which is used as the backing metal of the aluminum bearing alloy, was used as the second strip 2. The composition of the aluminum-based bearing alloy is, in weight percent, 20% Sn, 1% Cu, and the balance AI.

In Figure 2, the X marks are for roll ratios of 1.0, that is, the same diameter, the 0 marks are for roll ratios of 2.0, and the △ and O marks are for roll ratios of 6.0 and 1O06. The second pressure roll 6 has a larger diameter. Furthermore, Figure 2 shows the downstream ratio of each strip 1.2 when the total pressure F ratio obtained by pressure welding is converted to 40%. 1, that is, the lower part on the aluminum bearing alloy side is the downstream rate of the second strip 2, that is, the back metal side. In addition, when the re-pressing rolls 5.6 are made to have the same diameter, a gear mechanism or the like may be provided in the drive system of each of the pressing rolls 5.6 to make the rotation speeds of the two different.

As can be understood from the experimental results shown in FIGS. 2 and 3, by increasing the circumferential speed ratio, the pressure F ratio on the backing metal side can be lowered, and therefore the degree of work hardening can be reduced. The hard bearing material of the back metal not only makes machining relatively difficult when manufacturing it as a bearing, but also makes it difficult to obtain high roundness or straightness of the bearing, and also makes it difficult to manufacture 4111 bearings. The bearing may be easily deformed due to the large specific residual stress that remains inside the bearing afterwards.
This also has a negative effect on the bearing performance, but by reducing the downstream rate of the back metal side, such drawbacks can be improved.

In addition, the results of this experiment confirm that when the roll ratio is increased with the peripheral speed ratio set to 1.0, the rolling reduction ratio on the back metal side decreases, but especially when the roll ratio is increased, the rolling ratio is increased. As a result, the degree of decline in the downstream rate on the side of slush funds becomes remarkable, and it is understood that a synergistic effect can be obtained between the two.

As described above, according to the present invention, since the rolling reduction ratio of each strip in the composite material can be controlled, it is possible to obtain a relatively soft composite material suitable for use in bearings, for example.

In particular, in the present invention, since the second strip is inserted through the gap without substantially touching the pressure roll, a thick steel plate for backing metal, etc., which is difficult to curve, is used as the second strip. The effect is that it is easy to use.

[Brief explanation of the drawing]

Fig. 1 is a schematic overall configuration diagram showing an embodiment of the present invention, Fig. 2 is a graph showing the relationship between the circumferential speed ratio and the rolling reduction rate, and Fig. 3 is a graph showing the relationship between the circumferential speed ratio and the back metal as the second strip. It is a graph showing the relationship with hardness.

Claims (1)

[Claims] In a composite material pressure welding method in which first and second strips are inserted into a gap between a pair of pressure rolls that rotate in opposite directions and are pressed into contact with each other, the first strip is wound around one of the pressure rolls, and then A composite material, characterized in that the second strip is inserted through the gap, the second strip is inserted through the gap without being substantially wound around the pressure roll, and the circumferential speeds of the pair of pressure rolls are different. H1 contact method.