JPS6049055B2 - Roll forming equipment - Google Patents

Description

Detailed Description of the Invention (Technical Field) A roll forming device according to the present invention continuously bends and forms a strip-shaped metal plate (workpiece) fed in the length direction across the width direction to form a piston ring or the like. It is used to make various edge metals, precision parts for OA equipment, etc.

(Background of the Invention) For example, a piston ring spacer having an annular shape as shown in FIG. 1 and a cross-sectional shape as shown in FIG. 2 can be produced by bending a metal plate having a shape as shown in FIG. built.

The workpiece 2, which is a metal plate, is first bent into a cross-sectional shape as shown in FIG. 2 before being formed into an annular shape as shown in FIG. Each set is carried out successively by a plurality of rolls arranged in series with each other. Briefly explaining such a roll forming operation with reference to FIG. 4 showing an embodiment of the present invention, the workpiece 2 sent from the right end to the left in FIG. ) is formed into a cross-sectional shape as shown in FIG. 5 while passing through the second set of rolls 4a, 4b, and then the third set of rolls 5a, 5) is formed into the fourth set of rolls 6a,
6b, it is shaped into a cross-sectional shape as shown in FIG.

This workpiece 2 is further formed into a cross-sectional shape as shown in FIG. 7 while passing through a fifth set of rolls 7a, 7b, and is further formed into a cross-sectional shape as shown in FIG. 7 by a sixth set of rolls Ba, 8b. The cross-sectional shape shown in FIG. 8 is formed by the seventh set of rolls 9a, 9b, and then the cross-sectional shape shown in FIG. 10 is formed by the eighth set of rolls 10a, 10b. Molded into a cross-sectional shape. The workpiece having the cross-sectional shape shown in FIG.
3b, a set of two rolls 15, 15a presses each of the 9th to 11th sets of rolls and the workpiece from the lateral direction.
As a result, the cross-sectional shape shown in FIG. 2 is J-shaped. However, when a workpiece is simply bent between two or more sets of rolls as in the past, the following problems occur.

In other words, when a workpiece is bent by roll forming, unless the cross-sectional shape of the wire after forming is a simple shape such as an L-shape or a semicircular arc, the cross-sectional shape of the workpiece does not come into contact with the surface of any of the rolls. It is inevitable that some aspects will arise. For example, when a workpiece having a cross-sectional shape as shown in FIG. 10 is further roll-formed into a cross-sectional shape as shown in FIG. 2, the side rolls 15 and 15a are This metal plate 2 is now pressed from the left and right, and the surface drawn with thick lines in Fig. 10 does not contact the surface of any of the rolls.
The area inside the thick line above becomes a cavity. Therefore, when a set of rolls presses the workpiece 2 in the direction of the arrow in FIG. 10 and attempts to bend the workpiece 2 into the cross-sectional shape shown in FIG. This causes deformation to escape inward of the cavity, making it difficult to perform accurate bending that matches the surface shape of the roll. This amount of deformation is not that large and does not pose much of a problem under normal circumstances, but in the case of piston ring spacers and other precision parts, even a slight distortion in the cross-sectional shape will result in a defective product, so it is subject to damage during molding. Parts of the workpiece must be prevented from escaping into the cavity. For this reason, a core material called a mandrel has conventionally been used to prevent the workpiece from escaping into the cavity. However, in the conventional fixed mandrel type workpiece formed by rolls, the workpiece is fed while being in sliding contact with the surface of the mandrel, and thus a frictional force is generated between the workpiece and the mandrel. This frictional force increases in proportion to the force applied from both sides by the rolls, so when the pressing force from the rolls is increased in order to perform precision machining, the frictional force that acts between the mandrel and the workpiece increases. If the pressure becomes too large, the mandrel may be damaged, the roll drive mechanism may malfunction, or the workpiece may become abnormally deformed. (Object of the Invention) An object of the present invention is to provide a roll forming device that can eliminate the above-mentioned disadvantages and smoothly perform precise roll forming without friction between the mandrel and the workpiece. It is said that

(Structure of the Invention) The roll forming apparatus of the present invention has an endless ring-shaped mandrel that prevents deformation of the metal plate during roll forming of the metal plate as a workpiece. The structure is such that the mandrel entering the inside of the metal plate can move together with this metal plate.

For this reason, the mandrel can completely prevent the metal plate from deforming inward when it is formed by rolls, and since the mandrel and the metal plate do not rub against each other, the mandrel No force is applied to the rollers or rollers.

(Embodiments of the Invention) Next, the present invention will be explained in more detail by explaining the illustrated embodiments.

FIG. 4 shows an apparatus for forming a belt-shaped workpiece into a predetermined cross-section by roll forming, and then coiling the entire workpiece into an annular shape.

1st set of rolls 3) A, 3b to 8th set of rolls 10a
, 10b press the workpiece in the vertical direction of FIG.
The parts up to the cross-sectional shape shown in FIG. 10 are the same as the conventional device. In the roll forming apparatus of the present invention, a workpiece 2 having a cross-sectional shape as shown in FIG.
further press from the side as shown by the arrow in the same figure to create a second
Side rolls 15, 15a to be formed into the shape shown in the figure
and 9th set of rolls 11a, 11b1 m-th set of rolls 12
A, 12b1 A straight portion of the elliptical and "endless" mandrel 14 is located at the portion between the eleventh set of rolls 13a and 13b. That is, the mandrel 1 has flexibility and has a cross section that almost matches the cross section of the cavity inside the workpiece after roll forming.
The mandrel 1 is supported by a plurality of sets of guide rollers 16, 16, and has an oval shape in which two semicircular arc portions and two straight line portions are alternately continued.
One straight part of 4 is the ninth set of roll 11a and roll 1.
1b, between the wth set of rolls 12a and rolls 12b, between the 11th set of rolls 13a and 13b, and between each side roll 15, 15a. The lower side of this endless mandrel 14 is fed from the right to the left in FIG. 4, and is connected to the workpiece from the opening side (upper side in FIG. The side rolls 15, 15a and the ninth
-11 sets of rolls to move the metal plate to the left in FIG. 4 together with the metal plate. In the illustrated example, 2
Among the side rolls 15, 15a provided in sets, the first set of side rolls (the right side roll in FIG. 4)
15 and 15a, the cross-sectional shape shown in FIG.
It is molded to the cross-sectional shape shown in the figure, and then the second set of side rolls (the left side roll in Figure 4) 15, 15a
It is then molded into the cross-sectional shape shown in FIG. 12.

The cross-sectional shape shown in FIG. 12 corresponds to the cross-sectional shape of the piston ring spacer 1 shown in FIGS. 1 and 2. When forming the workpiece into the cross-sectional shape shown in FIG. 12, the workpiece 2 is
is strongly pressed from both sides, but since the mandrel 14 has entered the cavity inside the workpiece 2, the workpiece 2
The wall surface of the workpiece 2 does not deform toward the inside of the cavity.
The cross-sectional shape of can be formed accurately as desired. Further, since the mandrel 14 supported 1 by the guide rollers 16, 16 circulates as shown by arrow a in FIG. 4 as the workpiece 2 moves, the mandrel 14 and the workpiece 2 are The molding devices do not rub against each other strongly, and no force is applied to any part of the molding device. After forming the workpiece 2 into a predetermined shape, the mandrel 14 is pushed out from the cavity of the workpiece 2 by a peeling shoe 28 provided behind the eleventh set of rolls 13a, 13b, and the mandrel 14 is pushed out from the cavity of the workpiece 2. only is sent to a coiling device, which will be described later. Further, in FIG. 12, 29 is an upper guide that enters the upper end of the cavity of the workpiece 2 being fed between the rolls and prevents the workpiece 2 from sliding in the lateral direction, and 30 is the upper guide. This is a lower guide that comes into contact with the lower surface of the workpiece to prevent the workpiece from shifting downward. The workpiece 2 whose cross section has been formed into a predetermined shape is then formed into an annular shape as shown in FIG. 1 to be used as a spacer for a piston ring, but in the embodiment shown in FIG. 4, it is roll formed. A coiling device for forming a workpiece into an annular shape to form a piston ring spacer is provided at the rear portion of the device (the left end portion in FIG. 4). As shown in an enlarged view in FIG. 13, this coiling device has a pair of upper and lower rolls 17.
, 18 and a bending ring 19 (slightly smaller in diameter than the completed piston ring spacer) rotating between the rolls 17 and 18, and the workpiece is deformed toward this bending ring 19. A bending shoe 20 and a roller 2 that presses the workpiece 2 after passing through the bending shoe 20 against the outer peripheral surface of the bending ring 19.
1, 21 and a scraper 2 for removing the workpiece 2 wrapped around the outer peripheral surface of the bending ring 19 from the bending ring 19.
It consists of 2. As shown in FIG. 14, a convex portion 23 is formed at the center of the outer peripheral surface of the upper roll 17 of the pair of upper and lower rolls 17, 18, and this convex portion 23 and the bending ring 19
This bending ring 1 is engaged with a groove 24 formed on the inner peripheral surface of
9 is prevented from shifting in the horizontal direction (front and back directions in Figure 4, left and right directions in Figure 14). Further, a convex portion 25 is formed on the outer periphery of the bending ring 19 so that the convex portion 25 can just enter into a cavity that is open to the inner circumferential side of the workpiece 2 . On the other hand, a groove 26 is formed on the outer peripheral surface of the lower roll 18, into which the workpiece 2 can just freely enter. The bending shoe 22 includes a bending ring 19 and a roll 18.
This is for pressing the workpiece 2 pushed backward from between the bending ring 19 and forming the workpiece 2 into an annular shape that matches the outer diameter of the bending ring 19. Ring 1
A surface 20a facing the outer circumferential surface of 9 is an arcuate surface.
Since the bending shoe 22 alone is insufficient to bend the workpiece 2, the rollers 21, 21 reduce the inner diameter of the workpiece 2 by pressing the workpiece 2 after passing through the bending shoe against the bending ring 19. It serves to bring the outer diameter of the bending ring 19 closer to the outside diameter. The scraper 22 is for peeling off the processed piston ring spacer, which has been bent into an annular shape and wrapped around the bending ring 19, from the outer periphery of the bending ring 19 and dropping it onto a product receiver or the like. In the drawing, 27 indicates the 11th set of rolls 13a, 13 when the workpiece is short.
A feed roll 31 is used to smoothly feed the workpiece after passing through b to the coiling device, and a receiving roll 31 holds down the bending ring 19 pushed leftward in the drawing by the rows 21 and 21 from the right. (Effects of the Invention) As described above, the roll forming apparatus of the present invention is provided with a mandrel that enters the cavity inside the workpiece and moves together with the workpiece, so that Molding work can be easily performed without friction with the workpiece unlike with conventional fixed mandrels, and no excessive force is applied to any part of the molding equipment, which increases the durability of the equipment. It will also be a victory.

In addition, low-cost mass production is possible by roll forming, even with precision cross-sections that were conventionally considered impossible.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing a piston ring spacer as an example of the O workpiece formed by the forming apparatus of the present invention, Fig. 2 is a sectional view of this spacer, and Fig. 3 is before bending forming. FIG. 4 is a schematic side view showing the overall configuration of the roll forming apparatus of the present invention, and FIGS. 5 to 12 are workpieces showing the state in which metal plates are successively formed by this forming apparatus. 13 is an enlarged view of section A in FIG. 4, and FIG. 14 is an enlarged cross-sectional view taken along line B--B in FIG. 13. 1: Piston ring spacer, 2: Workpiece, 3a,
3b, 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7
b, 8a, 8b, 9a, 9b, 10a, 10b, 11A
,llb,l2a,l2b,l3a,l3b: roll,
14: Mandrel, 15, 15a: Side roll, 16
: Guide roller, 17, 18: Roll, 19: Bending ring, 2
0: Bending shoe, 20a: Surface, 21: Roller, 22: Scraper, 23: Convex portion, 24: Groove, 25: Convex portion, 26:
Groove, 27: Feed roll, 28: Peeling shoe, 29
: Upper guide, 30: Lower guide.

Claims (1)

[Claims] 1 In a roll forming device in which two workpieces are passed between multiple sets of rolls to form a cross section into a desired shape, an endless annular roller is placed between the rear rolls located near the end of the forming process. A mandrel, which is flexible and has a cross-sectional shape that allows it to just enter the cavity inside the molded workpiece, holds a part of the roll and circulates as the workpiece is moved by this mandrel. A roll forming device that is characterized by its flexibility.