JPH055592B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a composite material press-welding device for press-welding a first strip and a second strip together.

``Prior Art'' A conventional general press welding device for composite materials is equipped with a pair of work rolls of the same diameter that are rotated in opposite directions at the same circumferential speed, and a first strip, for example, an alloy strip, is inserted between the work rolls. A second strip, for example, a back metal strip, is inserted in an overlapping state, and both strips are joined together by the pressure applied by the pair of work rolls.

This pressure welding device does not have any problems as a general pressure welding device, but it did pose a problem, especially when manufacturing composite materials for bearings, in that the backing metal strip would undergo significant work hardening. .
In other words, in the above-mentioned pressure welding device, since the load per unit area applied to the alloy strip and the backing metal strip by the pair of work rolls is equal, the rolling reduction rate of each strip is uniquely determined by their materials. In particular, when the material of the alloy strip for bearings is an aluminum alloy and the material of the back metal strip is a steel plate, when the required total rolling reduction is obtained, the rolling reduction of the backing steel plate becomes larger than necessary. A hard composite material is obtained as a whole.

Such hard composite materials not only make machining relatively difficult when manufacturing them as bearings, but also make it difficult to obtain high roundness or straightness of the bearings, and also make it difficult to manufacture bearings. Since the bearing is likely to be deformed later due to the relatively large residual stress that remains inside the bearing, the performance of the bearing is also adversely affected.

Conventionally, in order to improve this problem, a pressure welding device for composite materials has been developed in which the diameters of the pair of work rolls are different, the work roll on the back metal strip side having a large diameter, and the work roll on the alloy strip side having a small diameter. is proposed.

According to this pressure welding device, since there is a difference in the contact area of the work roll in contact with each strip, the load per unit area applied to the backing strip can be made smaller than the load per unit area applied to the alloy strip. Therefore, when the required total rolling reduction is obtained, the rolling reduction of the backing strip can be kept relatively small to keep its work hardening small, thereby making it possible to obtain a soft composite material.

``Problems to be Solved by the Invention'' However, in this pressure welding device, the rolling reduction rate of each strip mainly corresponds to the diameter of each work roll. It was necessary to change the diameter ratio, and the changing work was complicated.

"Means for Solving the Problems" In view of these points, the present invention makes the diameter of the work roll on the second strip side serving as the back metal larger than the diameter of the other first work roll, and The circumferential speed of the work roll on the strip side is driven at a higher speed than the circumferential speed of the work roll on the first strip side, and the rolling reduction ratio of the second strip is set to the same circumferential speed of the pair of work rolls as the first strip. A drive mechanism is provided to control the rolling reduction rate to be smaller than that when the second strip is brought into pressure contact with the second strip.

``Function'' According to such a configuration, it is possible to control the rolling reduction ratio of each strip simply by changing the circumferential speed without replacing the work roll, and therefore the adjustment work is facilitated.

"Example" The present invention will be described below with reference to the illustrated example.
In FIG. 1, 1 is a supply reel for the back metal strip 2 as the second strip, and 3 is the supply reel for the alloy strip 4 as the first strip. are superimposed on each other and passed between a pair of upper and lower work rolls 5, 6, pressed against both work rolls 5, 6 to form a composite material 7, and wound up by a take-up reel 8.

In the illustrated embodiment, the work roll 6 on the back metal strip 2 side is set to have a larger diameter than the work roll 5 on the alloy strip 4 side, and the pair of work rolls 5 and 6 are rotated in opposite directions by the same drive source 9. This allows forcible drive in both directions at the same rotation speed.

In this way, when the diameter of one of the work rolls 6 is increased, the circumferential speeds of both work rolls can be made different even if the rotational speeds of both work rolls 5 and 6 are the same. In this embodiment, the back metal strip 2 The circumferential speed of the work roll 6 on the side is made greater than the circumferential speed of the work roll 5 on the alloy strip 4 side.

Further, a back-up roll 10 is provided on the back side of the small-diameter work roll 5, and a lower work roll 6, which is pivotally supported for rotation only, is moved through the back-up roll 10 by a lowering mechanism (not shown). The roll 5 is urged to be pressed against the roll 5. Note that this back-up roll 10 is rotated by frictional force with the work roll 5.

In order to make the peripheral speeds of the pair of work rolls 5 and 6 different, each of the work rolls 5 and 6 may be driven by an independent and separate drive source, or each of the work rolls 5 and 6 may be driven at different speeds. Appropriate means can be used, such as providing a system gear mechanism or the like to make the rotation speeds of the two different, but in this embodiment, the work roll 6 on the back metal strip 2 side is always
It is necessary to increase the peripheral speed of the work rolls 5 and 6, and in order to maintain the quality of the composite material 7, it is desirable to maintain a constant peripheral speed difference between the work rolls 5 and 6.

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 roll ratios) of a pair of work rolls 5 and 6 selected, and various ratios of peripheral speeds (hereinafter referred to as peripheral speed ratios) for each set of work rolls. This figure shows the results of measuring the respective rolling reduction ratios of the alloy strip and the back metal strip in the obtained composite material 7,
Moreover, FIG. 3 shows the results of measuring the hardness of the back metal strip at that time. In this experiment, a 1.38 mm thick cold rolled steel strip (SPCC-S) was used as the back metal strip 2, and a 1.40 mm thick aluminum alloy was used as the alloy strip 4. The composition of this aluminum alloy is 20% Sn, 1% by weight.
% Cu and balance Al.

In Figure 2, the × marks are for the roll ratio of 1.0, that is, the same diameter, the □ marks are for the roll ratio of 2.0, and the △ and ○ marks are for the roll ratios of 6.0 and 10.6.
The work roll 6 on the back metal side has a larger diameter. Furthermore, Figure 2 shows the rolling reduction ratio of each strip when the total rolling reduction ratio obtained by pressure welding is converted to 40%. is the respective rolling reduction rate on the alloy side.

As can be understood from the experimental results shown in Figures 2 and 3, even if the roll ratio is constant, increasing the circumferential speed ratio reduces the rolling reduction ratio on the backing metal side, and therefore causes work hardening. The degree of In addition, from the results of this experiment, it is confirmed that when the roll ratio is increased with the circumferential speed ratio set to 1.0, the rolling reduction ratio on the back metal side decreases. It is understood that when the circumferential speed ratio is increased for those with different diameters, the degree of reduction in the rolling reduction on the back metal side becomes remarkable, and a synergistic effect between the two can be obtained.

In the above embodiment, the supply reels 1 and 3 are used as supply means for supplying the back metal strip 2 and the alloy strip 4, respectively. For example, after each strip is rolled by a rolling machine, it is directly transferred to a pair of work rolls 5 , 6, it goes without saying that the rolling device constitutes the above-mentioned supply means. Similarly, in the above embodiment, a take-up reel 8 is used as a receiving means for receiving the composite material 7 pressed by the work rolls 5 and 6.
However, if the composite material 7 is directly supplied to a bearing forming device, the bearing forming device will constitute the receiving means.

Furthermore, although in the above embodiment two strips are pressed together, the present invention is not limited to this, and the above experimental results also show good results in terms of improved adhesion strength.

"Effects of the Invention" As described above, according to the present invention, each reduction ratio of the composite material can be controlled simply by changing the circumferential speed of a pair of work rolls. The adjustment work is easier than in the conventional apparatus, and since the diameters of the pair of work rolls are different, the rolling reduction ratio can be effectively controlled.

[Brief explanation of the drawing]

Fig. 1 is a schematic overall configuration diagram showing one embodiment of the present invention, Fig. 2 is a graph showing the relationship between the circumferential speed ratio and the rolling reduction ratio, and Fig. 3 is a graph showing the relationship between the circumferential speed ratio and the hardness of the backing metal. It is a graph. 1, 3... Supply reel, 2... Back metal strip, 4... Alloy strip, 5, 6... Work roll, 7... Composite material, 8... Take-up reel, 9...
...Drive source.

Claims (1)

[Claims] 1. A supply means for supplying a first strip, a supply means for supplying a second strip as a backing metal,
A first strip and a second strip supplied from each supply means.
In the composite material pressure welding device, the device includes a pair of work rolls that press the strips by inserting them in an overlapping state, and a receiving means that receives the composite material that has been pressure welded by the work rolls. The diameter of the work roll on the second strip side is made larger than the diameter of the first work roll, and the circumferential speed of the work roll on the second strip side is driven at a speed greater than the circumferential speed of the work roll on the first strip side. The present invention is characterized by being provided with a drive mechanism that controls the rolling reduction ratio of the two strips to be smaller than the rolling reduction ratio when the first strip and the second strip are brought into pressure contact with the pair of work rolls at the same circumferential speed. Pressure welding device for composite materials.