JPS603886B2 - Composite material extrusion manufacturing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an apparatus for manufacturing composite materials using a movable wheel type extrusion device which has no limit on the length of the material and can perform continuous extrusion. The present invention relates to a composite material extrusion device that can extrude materials with high efficiency and stability using a wheel.

A device for extruding a material using a single movable wheel having an endless groove is already known, as disclosed in, for example, Japanese Patent Application Laid-open No. 47-3185 or Tokusekki No. 49-6536. .

First, the mechanism for extruding material using such a movable wheel will be explained.

Since this mechanism itself is the same whether it is a single wheel or a plurality of wheels, in order to make the following explanation easier to understand, FIG. 1, which is an embodiment of the present invention, will be referred to, and FIG. This will be explained with reference to FIGS. 4 and 5. A movable wheel 10 used in this type of extrusion method has an endless groove 11 with a substantially U-shaped cross section formed on its outer circumferential surface, and a shoe block 13 is fitted in the endless groove. 11 and shoe lock 13 form a transport passage 16 into which material 15 for extrusion is forced. FIG. 4 is a partial sectional view showing the vicinity of the transport passage 16 in this case, and as can be seen from the figure, in the transport passage 16 the material 15 is in contact with the shoe block 13 on one side, whereas , endless groove 1
It is in contact with 1 on three sides. Therefore, the contact frictional resistance on each contact surface is three times greater on the endless groove 11 side than on the shuplock 13 side. In this state, with the contact pressure P of each contact surface, the shoe lock 13
is fixed and the movable wheel 10 is rotated. For example, if we consider the case where the wheel 10 is rotated toward the back of the figure, the contact friction resistance between the material 15 and the wheel 10 is much larger, so the material 15 is continuously fed toward the back of the figure by the wheel 10. It will be done. On the other hand, in the endless groove 11, as shown in a partial cross-sectional view in FIG.
The material 15 is prevented from moving at the back by this fixed block 19. Since the material 15 is still forcibly fed into the transportation passage 16 with the leading end of the material 15 being blocked, internal pressure is generated in the material 15 due to the forced feeding force, and the internal pressure becomes the extrusion pressure, and by providing a die at the back of the extrusion pressure, it is possible to obtain an extruded product of infinite length from the die. However, in the above extrusion method, since the source of the extrusion pressure is dependent on the contact friction resistance between the material 15 and the endless groove 11, there are some problems not seen in the conventional ram extrusion method. do.

The first problem is the structure.

That is, when internal pressure is generated in the material 15 as described above in FIG. 4, a force acts on the shoe lock 13 that is iron-coupled to the endless groove 11 to separate the shoe lock 13 from the endless groove 11. Therefore,
If the shoe lock 13 is not restrained with a restraining force Fn sufficient to compensate for this separation force, a gap will be created between the shoe flock 13 and the endless groove 11, and the material 15 will turn into burrs and overflow from the transportation path. This results in a decrease in extrusion pressure. Moreover, the internal pressure generated in this case is enormous, and it is technically quite difficult to completely hold down the shoe lock 13 rigidly against this internal pressure. The reality is that this holding structure has become extremely exaggerated and complicated. Second, there is the following major problem, which can be said to be fatal to the movable wheel system. In other words, as mentioned above, the pressure generation mechanism is made to depend on the contact friction resistance between the material and the grooved surface, but the adhesion between the material and the grooved surface is not always uniform on all contact surfaces during extrusion, and changes over time. Alternatively, it may vary depending on location, resulting in so-called dry slips.

When this slippage occurs, the pressure generated on the material naturally fluctuates, which causes fluctuations in the extrusion pressure and creates an imbalance in the flow of the material extruded from the die.
There is a risk of destabilizing the quality of the product.
In particular, the above problems become a major problem when manufacturing composite materials such as aluminum-coated steel wire. In other words, in order to extrude composite materials, it is necessary to arrange a nipple for supplying the core material in addition to the die, and if both the die and the nipple are to be provided at or near the shoe lock, the holding structure of the shoe flock will be affected. In addition, if the material flow becomes unbalanced due to fluctuations in extrusion pressure, the flow of the coating material covering the core material becomes uneven at the die part, resulting in an increase in wall thickness. This can be a major cause of product defects such as fluctuations, uneven thickness, or surface defects. As a result of various experiments and plastic mechanics analysis related to movable wheel type extrusion, the inventors found that the problems associated with the above-mentioned portable wheel type extrusion can be solved by using multiple wheels instead of a single wheel. We have found that significant improvements can be made by using them in combination.

The reasons why the problems associated with the movable wheel system can be solved by using a plurality of wheels will be explained below.

As we have already seen, the extrusion pressure for material extrusion in the movable wheel method depends on the contact friction resistance between the material and the groove surface of the wheel, so the pressure distribution of the material in the transportation passage is naturally dependent on the pressure distribution at the entrance of the passage. It's small and big in the back.

FIG. 6 is a diagram showing the actual pressure distribution situation,
An example is shown in which the arc angle of the part where the materials touch is ◇o = 90o, where 0 on the axis scale means the entrance of the passage, and 90 means the deepest point of the pilgrimage. Is P(J) on the vertical axis the angular coordinate from the entrance? The pressure value at the point oo is the yield stress of the material, and the vertical scale indicates how many times the pressure at that point is the yield stress. From FIG. 6, it can be seen that the pressure is small at the entrance of the passage and the pressure increases rapidly at the back of the passage. 6th
The existence of a pressure distribution as shown in the figure means that a corresponding separation force is also acting on the shoe block. Consider pressing from the outside.

Just as there is a center of gravity that can support static gravity at one point, even in the pressure distribution state shown in Figure 6, when trying to support something from the outside, there is a point that can support it from the outside, like the fulcrum of a balance. There is a point of concentration of balanced stress.
Let Jm be the angular coordinate of such a concentration point. Needless to say, when pressing the shoe block, it is most effective to concentrate the restraining force Fn on this point m. This value m is affected not only by the internal pressure of the material but also by the rotational moment caused by the rotation of the wheel, and also changes depending on the size of the contact angle o. Figure 2 shows such a contact angle? What is the relationship between o and gm? This is a diagram obtained as a solution to a theoretical formula for m (details of the theoretical formula are omitted). In the figure, 8 is the value of two peaks Rw/Ri, and the peak s is the coefficient of friction between the workpiece and the shoe block. 1 is the effective coefficient of friction of the workpiece, Ri is the radius of the workpiece before extrusion, and Rw is the radius of the wheel.
Here, the value of 0o can be selected as appropriate, but is the bale antenna usually used industrially? Since o is approximately 90o, the point m, which is the stress concentration point in such an extrusion device, is approximately equal to o, as can be seen from FIG.

If this point is suppressed by the restraining force Fn, theoretically the shoe block can be supported most efficiently at this one point. Now, consider a situation in which two wheels 10a and 10b are arranged as shown in FIG. 3, and one shoe block 13 is arranged between them as shown in the figure.

In Fig. 3, guo=900, so 1 ◇m in this case
According to the above figure 2, the angle is approximately 90o, which is exactly the 3rd angle.
Mark an X on the diagram? This corresponds to the position indicated by m. In this position, the separation force on the shoe block is concentrated at m, and it can be seen that at this position, the separation force applied to the shoe block directly acts as a restraining force Fn against the separation force from the opposite wheel. That is, the separation force from the wheel 10a directly acts as a restraining force Fn against the separation force from the wheel 10b, and conversely, the separation force from the wheel 10b directly acts as a restraining force Fn against the separation force from the wheel 10a. . In this way, the separation forces act on each other as an immediate restraining force, and there is no need to add a special holding mechanism to the shoe block to restrain it. Compared to the case of a single wheel, which requires a complex and exaggerated shape lock holding structure as described above, the benefits of using multiple wheels are obvious. The second problem with a single wheel, the instability of the pressure generated due to wheel slippage and the resulting uneven quality of the extruded product, is due to the fact that multiple wheels are used. In this case, slipping does not occur all at the same time, and this problem can be effectively solved by using a plurality of wheels. Therefore, the above-mentioned overflow when using a movable wheel type extrusion device for extruding composite materials can be effectively solved by using a plurality of movable wheels. As mentioned above, although the various problems encountered in the case of a single wheel have been solved by using multiple wheels, it has been found that there are still the following problems that need to be improved.

The effect achieved by using the plurality of wheels described above can be said to be achieved when the material is fed smoothly in each wheel, and if this is not the case, it may not necessarily be said to be sufficient.

For example, in FIG. 3, consider a case where one wheel 10a is slipping and the other wheel 10b is not slipping. Naturally, the internal pressure on the 10a side where the slippage occurred will be lower, and the internal pressure on the 10b side will be higher, causing the above-mentioned equilibrium of n to be broken, and there is a risk that an unexpected abnormal force will be applied to the shoe block. Furthermore, when the internal pressure on one side of the wheel is high and the other side is low, there is an imbalance in the extrusion pressure itself, which causes the material flow to become non-uniform near the die inlet. Even if it is not as bad as in the case of The purpose is to provide an extrusion device that can automatically correct the imbalance even if pressure fluctuations occur due to slippage, etc., and can always achieve stable extrusion. The shoe block comprises a plurality of movable wheels having endless grooves on the outer periphery thereof, and a shoe block that fits into the respective endless grooves of each of these movable wheels to form a transport passage for material extrusion and is itself movable. and a fixing block disposed opposite to the shoe block and closely adjacent to each of the endless grooves, and the gap between the shoe blocks and the fixing blocks facing each other is a space for the extruded material. Formed in a gathering room,
The transport passageway passes through the gathering room, and the shoe lock and fixed block include:
A composite material extrusion manufacturing apparatus is provided with a nipple for supplying a core material and a die for extrusion molding the composite material, which are provided facing each other. The present invention will be specifically described below with reference to embodiments shown in the accompanying drawings.

FIG. 1 is an explanatory sectional view showing an embodiment of a composite material extrusion apparatus according to the present invention using two movable wheels 10, 10.

A movable wheel 10 supported by mutually parallel shafts 12, 12 has endless grooves 11, 11 having a substantially U-shaped cross section formed on its outer peripheral surface.

On the other hand, separate from these movable wheels 10, 10, there is a shroud 13 that competes with the endless grooves 11, 11.
The shoe block 13 is supported by rollers 20, 20' and is configured to be able to move slightly in the direction of the arrow in the figure. Furthermore, the material 15,
15. Transport passages 16, 16 for moving the materials are formed, and one end of these transport passages 16, 16 is configured as a closed opening into which the materials 15, 15 can be inserted as shown in the figure. There is a fixed block 19 that completely seals the endless grooves 11 and 11 and fits tightly, and the material 15 fed to the fixed block 19 by the rotation of the wheel 10 is prevented from moving by this fixed block 19. It is being forcibly blocked. The space between the shoe lock 13 and the fixed block 19 is a collection chamber 18 for the material 15, as shown in the figure.
The material 15 whose movement is forcibly blocked by the fixed block 19 changes direction at the back of the passage 16 and collects in the collecting chamber 18. It is designed to be forced. In FIG. 1, reference numeral 17 denotes a die for extrusion molding a composite material 24, and a nipple 22 for supplying a core material 23 is located in a pond opposite to the die 17, and the core material 23 is attached to a fixed block 19. It passes through the guide path 21, is stratified by the nipple 22, and is guided and supplied to the center of the die 17, where the outer periphery is coated with the material 15, and the composite material 24 is extruded.

However, the arrangement relationship between the die 17 and the nipple 22 is the first.
It goes without saying that the relationship may be such that the nipple is arranged on the shoe lock 13 side and the die is arranged on the fixed block 19 side, contrary to the figure. Now, since the extrusion device according to the present invention is configured as described above, it can exhibit the following effects.

Now, in the extrusion pupil shown in FIG. 1, it is assumed that the wheel on the right side is slipping, and the wheel on the left side is operating normally without such slippage.

There is a difference in the way the material is fed into the left and right passages depending on the presence or absence of idle slip, and naturally the internal pressure in the left passage where there is no idle slip is higher than that in the right passage where idle slip is occurring. becomes higher than the internal pressure of That is, in FIG. 1, the relationship between the internal pressures R, and R2 is R,>R2, and since the shoe lock 13 itself is configured to be able to move slightly, it moves slightly due to the difference in internal pressure and moves to the right in the diagram. do. As a result, the space on the left aisle becomes wider and the space on the right aisle becomes narrower. The internal pressure decreases on the side where the space is wider, while the internal pressure increases on the side where the space becomes narrower. Then, the internal pressure will be reversed to R
．． <R2, and the shoe lock 13 is pushed back to the left side in the figure. In this way, even if the internal pressure in the passages of both wheels changes due to slippage, the shoe lock itself moves slightly in response to the change in internal pressure, and the internal pressure in both wheels is always maintained at a constant level. Since it acts to maintain an equilibrium state, it is possible to always obtain stable extruded products of good quality, and it is also possible to accurately prevent abnormal forces from being applied to the support structure of the shoe flock. be.

As described above, according to the extrusion device according to the present invention, the shoe block is configured to be able to move slightly in response to the difference in internal pressure that occurs in the transportation passage of each movable wheel.
In particular, it was able to automatically maintain the balance of extrusion pressure without making the device large-scale, and it was able to completely solve the problems that remained when multiple movable wheels were used. Not only is it possible to extrude high-quality products with much higher efficiency than with a single wheel, but it is also possible to extrude with higher stability than with multiple wheels and a fixed shoe block. By applying this to the extrusion of composite materials, which avoids fluctuations in extrusion pressure, the quality of products can be improved, and its industrial significance is enormous. There is something.

[Brief explanation of the drawing]

Fig. 1 is an explanatory sectional view showing one embodiment of the extrusion device according to the present invention, Fig. 2 is a diagram showing the relationship between the contact arc of the material and the best support point of the shoe block, and Fig. 3 is a diagram showing the relationship between the contact arc of the material and the best support point of the shoe block. 4 is a partial cross-sectional view showing the configuration near the transportation pilgrimage, and FIG. 5 is a partial cross-sectional view showing the ironing condition of the fixed block. FIG. 6 is a diagram showing the pressure distribution of the material within the transport passage. 10: Movable wheel, 11: Endless groove, 13: Shoe block, 15: Material, 16: Transport passage, 17: Die, 18: Gathering chamber, 19: Fixed block, 20: Roller, 2
2; nipple, 23; core/material, 24; composite material. 1. Figure 2. Figure 3. Longevity 4. Heron S Illustration

Claims (1)

[Claims] 1. A plurality of movable wheels having endless grooves on the outer periphery, a shoe block that fits into the respective endless grooves of each of these movable wheels to form a transport path for material extrusion, and is itself movable slightly; A fixing block is provided which is disposed opposite to the shoe block and tightly fits into each of the endless grooves, and a space between the shoe block and the fixing block facing each other is formed as one collection chamber for the extruded material. The transportation passage is communicated with the gathering chamber, and the shrew block and the fixed block are provided with a nipple for supplying the core material and a die for extrusion molding the composite material, facing each other. Composite material extrusion manufacturing equipment.