JPS6117576B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for continuous cold roll forming of a product having a predetermined cross-sectional shape and curved in the longitudinal direction, such as a bumper.

In the conventional continuous cold roll forming process of bumpers, each pair of forming rolls is arranged in tandem over multiple stages in the widthwise forming section.
A metal plate material (hereinafter referred to as a plate material) is supplied and first formed into a predetermined cross-sectional shape, and then the plate shape formed as described above is passed through three pairs of rolls along the circumference of a constant R. By passing the roll through the curved forming section arranged in the longitudinal direction, a certain bending R is applied in the longitudinal direction according to the arrangement position of the three sets of rolls, and the width direction forming section and the curved forming section are individually separated. Because the processing is simply combined, the curvature that can be formed into a curve without causing wrinkles or edge waves on the product surface using conventional roll forming is determined by the material, structure, and mechanical properties of the plate material and can be freely selected. There were disadvantages that I could not get. In addition, the roll forming process described above can only process curved products with a certain bending radius, so for example, in order to form both sides of a bumper into a particularly small bending radius, new pressing or stretching is required in the post-process. Processing such as bending must be performed. Furthermore, after the bumper is formed through the above process, it is plated, which requires multiple steps such as buffing. Since it is difficult in terms of equipment and space to carry out this process on products that are produced by molding, conventionally, each product had to be separated when molding was completed, and then the buffing process described above had to be performed on each product. There are limitations and a large number of man-hours are inevitably required, which has the disadvantage of increasing manufacturing costs even though the parts are relatively simple.

The present invention has been made in view of the above points, and its main purpose is to form a sheet material into a predetermined cross section at a time by each forming roll during width direction forming, and at the same time to A required side surface in the longitudinal direction of the plate material to be added, for example, the bottom plate part (S ₁ in Fig. 2)
By creating a pre-strain in the plate material and then continuously performing curve forming in the longitudinal direction of the plate material so that the side portions of the plate material are stretched, products with excellent surface precision can be continuously roll-formed. The present invention provides a continuous cold roll forming method for curved bumpers and an apparatus therefor.

Another object of the present invention is to provide a continuous cold roll forming method for curved bumpers, which enables continuous roll forming to periodically form different curvatures on the product, and an apparatus therefor.

Therefore, when roll forming curved bumpers, the more you can obtain a product with excellent surface precision that does not require secondary processing upon completion of forming, the less post-processing will be required. By washing and polishing, it is possible to perform minimal buffing while keeping the product in a continuous state after molding, making it possible to send the product to the plating process by simply dividing it into parts, which allows for consistent processing from supplying the plate material to just before the plating process. However, the conventional roll forming method described above simply combines processes in different forming directions, i.e., the width direction and the longitudinal direction. Since it is difficult to eliminate the problem almost completely, the above objectives and technical problems cannot be solved by simply changing the design of the forming roll used in the conventional method or increasing or decreasing the number of forming stages. is clear.

That is, in order to continuously form bumpers with a predetermined cross-sectional shape, the present invention is obtained by connecting points on the profile of each forming roll that correspond to a curve in which a certain point of the plate material is displaced by a series of forming rolls. A curve (hereinafter referred to as a path line) is set with a non-orthogonal condition to the plane containing the axes of a pair of forming rolls, and a curve is set between the pair of forming rolls of each forming roll at an angle to the plane containing both rotational axes. By supplying a plate material from the direction and simultaneously applying roll forming in the width direction, a preliminary (elongation) strain is applied step by step to the desired longitudinal side of the plate material, such as the bottom plate, using each roll. This makes it possible to eliminate molding defects due to stress distortion that occurs in the process.

Therefore, the gist of the present invention is the following three technical configurations.

(1) Each pair of forming rolls connected in multiple stages is formed as a pass line that is initially inclined upward and then inclined downward from the middle to the later stages, and the desired plate material is guided to this pass line, and the forming rolls are The material is fed in a non-orthogonal state to the plane including the roll axis, roll-formed in the width direction and at the same time imparts a desired pre-strain in the longitudinal direction to the required side surface, and then curve-formed so that this part is on the outside. point to do.

(2) A point where a desired pre-strain is applied to the plate material, and then different curvatures are periodically and continuously shaped with this area on the outside.

(3) The product is polished and washed before roll forming, and after widthwise forming, the curved product is continuously buffed.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an apparatus used to carry out the method of the present invention, in which a plate material S is supplied to the apparatus from an uncoiler section (not shown) set in a coiled state via a known coil connecting machine and an accumulator. In the process progressing from the left side to the right side in Figure 1, the following processes are performed: pre-polishing, cleaning, roll forming in the width direction, curve forming, final polishing, and cutting. Hereinafter, 1 is composed of a free wheel 1a that contacts the lower surface of the plate material S to be fed, and a drive wheel 1b that presses against the upper surface of the plate material S directly above the free wheel 1a and rotates in the opposite direction to the feeding direction of the plate material S. A sheet polisher 2 for polishing the upper surface of the plate material S, each equipped with a pair of rolls, and a sledging roll 2a that can clean both the upper and lower surfaces of the plate material S to the extent that it can be plated with minimal polishing in the post-process, and a brushing roll. A cleaning leveler consisting of a roll 2b, a ringer roll 2c, a plurality of pairs of leveler rolls 2d for final straightening of the plate material S, and a pinch roll 2e for pinching the plate material S, 3 is an entry table, 4 is a preliminary stand 5, This is a roll bed for arranging a width direction roll forming section 6 and a curved roll forming section 7, which will be described later, in the same order. 6 _1～12
is a total of 12 roll stands constituting the width direction roll forming section 6 in which the pass lines of each pair of forming rolls 6a _{1 to 12} and 6b _{1 to 12} are set to be inclined along the feeding direction of the plate material S. , the above forming roll 6
a _{1 to 12} and 6b 1 _{to 12} are made of a material having one side surface of the plate material S that gives the desired prestrain, that is, the bottom plate portion S ₁ (see Fig. 2), and the cross section in the width direction is approximately U-shaped on its side. Each of the forming rolls has a required profile that gradually increases in diameter so that the product C can be roll-formed in a total of 12 stages, and when curve-forming is performed so that the bottom plate part _S1 is on the upper side, the pair of roll shafts of each forming roll is The pass line formed by each forming roll with respect to the plane including the axes 6a and 6b is set to be inclined upward with the first stage roll stand ₆₁ as a base point, thereby ensuring proper roll alignment between each forming roll. The structure is such that the plate material S can be supplied into the gap g (see FIG. 4) from an inclined direction.
(In addition, the slope is exaggerated in FIG. 4). Also, instead of setting the slope of the pass line, a pair of roll axes 6
A similar effect can be obtained even if a and 6b are arranged with a difference in the front and back. The quantitative range in which the pass line should be tilted upward is appropriately increased or decreased in accordance with the curvature selected by the curvature forming section 7, which will be described later. 7 _{1 to 3} each have a pair of curve forming rolls 7a _{1 to 3} and 7b _{1 to 3} , and height adjustment mechanisms 8 _{1 to 3} provided respectively allow the plate material holding portions of each pair of rolls to hold the plate material S. This is a movable roll stand arranged on the circumference of the radius to be curved. Note that this movable roll stand 7 is
As shown in Figure B, by making it rotatable around the shaft 7a and fixing it at a desired position, in addition to adjusting the height, the pitch p between the rolls can also be adjusted, allowing the range of desired curvature to be applied. can be expanded.

Next _, as _shown in _{FIG .}
The roll position is moved up and down in synchronization with the transport speed of the plate material. In this case, as shown in FIG. 3, there is a main drive shaft 8a with a worm, a worm wheel 8b that meshes with the worm, a gear 8c that is coaxially connected to the wheel 8b, and a reverse gear 8d that meshes with the gear 8c.
The pair of curved rolls 7a ₂ , 7 (for example, in FIG. 1) are connected to each shaft of
The roll shafts 8f, 8g rotate _b2 synchronously and reversely while forming the plate material S, and the pair of cam shafts 8h, 8i are synchronized with the roll shafts 8f, 8g by meshing with the gear 8c. A gear mechanism G configured to be drivable and a convex portion j fitted on the camshaft 8h.
a cam A having a cam A, a cam B having a recess k corresponding to the protrusion j fitted on the cam shaft 8i, and a free roll 8 that freely rotates in contact with both cams A and B.
8m loosely fitted into each end, the frame itself is swingable around a fixed shaft 8o installed on a frame 8n, and an elongated hole 8 bored at the other end.
A pair of arms 8 whose portions p and 8q are arranged directly below the movable roll stands (for example) 7 ₂ , 7 ₂
r, 8s and long holes 8p, 8 of each arm 8r, 8s
The movable roll stand (for example) 7 ₂ , which has notches 8v and 8w which accommodate the drilled portion q and which is provided with spindles 8t and 8u that are fitted into the respective elongated holes 8p and 8q.
Slide members 8x and 8y fixed to the lower end of 7 ₂
Guide grooves 4a and 4b are provided in the roll bed 4 to accommodate the slide members 8x and 8y in a vertically movable manner, and a total of 16 pieces of wear are attached to each guide groove and each slide member, 4 pieces each on one side. Consisting of plates 4c and 4d, cam A,
By appropriately selecting the average circumference of cam B, it is possible to adjust the gap between different curved portions that are periodically formed on product P, and also to adjust the size of convex portions j and concave portions k of cams A and B. By making an appropriate selection, the degree of the curvature can be selected, and the rotation of the cams A and B is stopped at a predetermined position by an operation mechanism (not shown) interposed in the gear mechanism G, whereby the roll axis 8f, 8
The roll stand, which does not require periodic height adjustment, is constructed so that the height can be fixed while maintaining the rotation of g. The curved forming section 7 is formed by each pair of rolls 7a ₁ , 7b _{1 -7a} 3 , by the height adjustment mechanisms 8 1 - ₃ .
_7b3 can be arranged on the circumference of a circle of arbitrary curvature, but the center of this circle is set in the direction in which the bottom plate part _S1 is stretched corresponding to the pass line of the width direction forming part set upward, that is, below the pass line. do. Reference numeral 9 denotes a five-stage buffing section 10 which is installed immediately after the curved forming section 7 and is capable of continuously finishing and polishing the outside of the continuous product C that has been rolled formed to the extent that it can be plated.
Reference numeral 11 indicates a cutting section for cutting the continuous product C into products C ₁ to C o of a certain length, and a conveyor 11 transfers the products C ₁ to C o to a subsequent plating booth (not shown).

Next, the molding method of the present invention will be explained based on the above-described configuration. When the plate material S is sent to this device after a pre-processing process (not shown), it is first polished and cleaned by a sheet polisher 1 and a cleaning leveler 2, and then passed through an entry table 3 and a preliminary stand 5 to be transferred to the first stage. Facing roll stand 6 ₁ ,
As shown in the figure, the pair of forming rolls 6a ₁ and 6b ₁
Due to the forming force applied to the sheet material S as it enters the roll gap g determined according to the roll profile of The shape is shaped in the width direction of the plate material. In this way, the plate material S that has undergone the first stage of roll forming is transferred to the second and third stages.
~ Each forming roll 6a ₂ ~ 6a ₁₂ , 6b ₂ ~ 6 of the 12th stage
By passing through b ₁₂ , the same roll forming as described above is performed according to the gap between the rolls, and the plate material S is finally formed into a substantially gate-shaped cross section. Because it is supplied in a non-orthogonal state to the plane P including the pair of forming roll shafts 6a and 6b based on the pass line set at an angle (the fourth
(Fig.), the plate material S is bent so as to be almost curved by the circumferential surface of the lower forming rolls 6b _{2 to 12} immediately before the above-mentioned plane P, and after passing over the plane P, the plate material S is bent by the upper forming roll corresponding to each of the above-mentioned rolls. 6a _{2 to 12} are bent back in the opposite direction along the circumferential surface, and this bending and returning is mainly performed by forming rolls 6 of each stage in the longitudinal direction with respect to the bottom plate part S ₁ of the plate material S.
This is performed in stages by a _{2 to 12} and 6b _{2 to 12} , thereby giving the bottom plate portion S ₁ an elongation strain for curve forming. At this time, it is preferable to apply tension to the plate material S by sequentially increasing the diameter of the pair of rolls in each roll stand and sequentially increasing the circumferential speed of the rolls, thereby facilitating the application of elongation strain. In the widthwise roll forming section 6, rotatable side rolls 6c and 6c' are provided to prevent wrinkles from forming as widthwise forming progresses, as shown in FIG. 2B. The plate material S, which has been roll-formed with the necessary elongation strain given in this way, reaches the curved forming part 7 connected to the width direction roll forming part 6 as a semi-finished product, and from the above-mentioned upwardly inclined pass line, The three sets of curved rolls 7a ₁ and 7b ₁ of this stage, which are connected along the circumference of the reversely warped constant curvature R, are entered from the tangential direction to the above curvature R with the bottom plate portion S ₁ as the outer circumferential circle. Since it is curved approximately along the bottom plate part S ₁
A tensile load is continuously applied to the
Most of this load can be absorbed by the elongation strain formed in the bottom plate portion _S1 , and there is no risk of it being spread to other parts, so curve forming can be performed extremely smoothly. In this way, three sets of curved rolls 7
Product C curved by a _1~3 , 7b _1~3
By arranging each roll on a circumference with an appropriate curvature, roll forming can be performed by freely selecting the curvature that can be absorbed by the elongation strain (see FIG. 5A).

In the width direction roll forming part 6 in the above embodiment,
Although a 12-tier loin stand was installed and a 3-tier roll stand was installed in the curved roll forming section 7,
Of course, the number is not limited to this, and the number of stages can be increased or decreased as necessary.

Next, when operating any of the height adjustment mechanisms 8 _{1 to 3} of the movable stands 7 ₁ to 3 in order to obtain a product whose curvature changes as shown in FIG. ₂ ), the free roll 8l between them is rotated synchronously with the rotation of the curved rolls 7a ₂ and 7b ₂ by the uneven portions k and j of the cams A and B.
The arms 8r and 8s swing through the cams, and the roll shafts 8f and 8g are periodically moved up and down through the slide portions 8x and 8y. curved roll 7
Displacement position of a ₂ , 7b ₂ and other curved rolls 7a ₁ , 7b ₁
The curvature R ₁ of the tangent circle of 7a ₃ and 7b ₃ is periodically shaped (see Figure 5 B), and a product C', in which different curvatures are periodically shaped, is formed by continuous roll forming. It can be manufactured.

As mentioned above, product C with constant curvature (see Figure 5 A)
For this purpose, the curved peripheral surface of the product C is continuously polished by the buff of the buff polishing unit 9 connected to the movable roll stand ₇₃ at the last stage to make it a plateable product, and then cut. In section 10, the sheet is cut into a predetermined length and conveyed by conveyor 11 to the subsequent plating process. For cutting, it is preferable to use the well-known flying shear method, and when measuring the length, the number of revolutions of the forming roll drive shaft is measured, and this is converted into a circumferential length by a controller (not shown), and a cutting command signal is issued at the appropriate time. It is better to operate the flying shear. Alternatively, the command signal may be generated by bringing the end of the product into contact with a stopper device provided at a predetermined position. As mentioned above, product C is pre-polished by sheet polisher 1 in the state of sheet material S, and will be subjected to final polishing in the post-process, so buffing, which was conventionally done in a separate process, can be done by roll forming. It can be done continuously and efficiently.

In addition, in the case of shapes with different curvatures, it is possible to cut them once with a cutting device immediately after exiting the roll of the height adjustment mechanism 8, and perform post-buffing separately. Since the cutting is performed immediately after cutting, the displacement of the cutting portion due to the change in the curvatures R and R' is small, and a conventional traveling cutting machine can also be used satisfactorily.

According to the present invention, since the plate material is pre-strained in the longitudinal direction, it is possible to absorb the tensile load during curve forming, and it is possible to continuously roll form extremely high quality curved products. According to the present invention, the degree of
Since the pass line of the plate material is continuously formed from an upwardly inclined state to a downwardly inclined state, the surface during the bending process is always kept on the upper surface, and the bent portions of both ends of the plate material are located on the lower side, Therefore, polishing processes such as sheet polishing in the pre-processing process can be performed from the top without difficulty, and the coolant (cooling liquid) during roll forming process can be flowed out without accumulating, making work more efficient. Furthermore, since the curved roll forming section in the latter stage is tilted downward, roll processing and cutting are performed above ground or slightly underground, allowing for safe and efficient work, and the processing surface is on the front side. This has the effect that the surface will not be damaged even when transported on a conveyor after cutting. In addition, several sets of forming rolls are installed on a movable stand at the last stage of the curved roll forming section to maintain a desired radius of curvature. Different curved shapes can be shaped periodically, and furthermore, pre-polishing and final polishing can be performed before and after roll forming, making it possible to finish the product so that it can be plated, so the processing from supplying the plate material to just before the plating process can be done consistently. This makes it possible to efficiently manufacture long objects such as bumpers with one device.

[Brief explanation of the drawing]

FIG. 1A is an explanatory central longitudinal sectional view showing one embodiment of the apparatus used in the present invention, FIG. 1B is an explanatory view showing a modification of the curved roll forming part in FIG.
Figure A is an explanatory diagram showing an example of the forming process of plate material S by roll forming, Figure 2B is a sectional view taken along the - line in Figure 1A, and Figure 3 is an example of the roll stand height adjustment mechanism. In the same figure, A is a front explanatory view, B is the third
FIG. 4 is an explanatory diagram showing an example of forming elongation strain in a plate material according to the present invention, and FIG. 5 A and B are plan views of two types of bumpers that can be manufactured according to the present invention. . 1...Sheet polisher, 2...Washing leveler,
3...Entry table, 4...Bed, 5...
...Spare stand, 6...Width direction roll forming section, 6
_1~12 ...Roll stand, 6a _1~12 , 6b _1~12
...Forming roll, 7...Curved roll forming section, 7 _1
~3 ...Movable roll stand, 7a _1~3 , 7b _1~3
...Curved roll, 8 _1-3 ...Height adjustment mechanism, 9...
... Buffing section, 10... Cutting section.

Claims (1)

[Scope of Claims] 1. A sheet polisher that polishes the surface of a plate-shaped material and a cleaning leveler that cleans both the upper and lower surfaces of the material are used to polish and clean the material in advance, and then the material is sequentially tilted from an upwardly tilted state to a downwardly tilted state. The material is fed in a non-orthogonal state to the plane including the roll axis by each pair of forming rolls arranged in multiple stages, and roll forming is performed in the width direction in the above-mentioned upwardly tilted state, and at the same time, the material is A desired pre-strain is applied with a roll, and the material is curved in the longitudinal direction so that the pre-strained portion is stretched in the downwardly tilted state. After successive buffing, the material is cut with a cutting machine. A continuous cold roll forming method for curved bumpers characterized by dividing them into appropriate lengths. 2. A middle direction roll forming section, which is equipped with a sheet polisher and a cleaning leveler for polishing and cleaning the plate-shaped material in the front stage, and in which the pass line formed by each pair of forming rolls arranged in multiple stages provided in the middle stage is tilted upward. and a downwardly inclined curved roll forming section, and can impart a desired pre-strain to the plate-shaped material formed by each forming roll with respect to a plane including the roll axes of the pair of forming rolls. , a continuous cold roll forming apparatus for curved bumpers, characterized in that the continuous cold roll forming apparatus is configured to be set in a non-orthogonal state, and is provided with a buffing part for final polishing of the material and a cutting part for dividing the material at a subsequent stage. 3. The pass line formed by each pair of forming rolls arranged in a row in multiple stages is continuously constituted by an upwardly inclined width direction roll forming part and a downwardly inclined curved roll forming part, and the above pair of rolls At least three sets of forming rolls disposed at the last stage are set in a non-orthogonal state that can impart a desired prestrain to the plate-shaped material formed between each roll with respect to a plane including the axis. is provided on a movable stand that can be selectively arranged on the circumference having a desired radius of curvature, and is equipped with a sheet polisher and a cleaning leveler for polishing and cleaning a plate-shaped material at the front stage, and a cleaning leveler for finishing polishing the material at the rear stage. A continuous cold roll forming device for curved bumpers, characterized by comprising a buffing section and a cutting section for dividing. 4. A curved bumper according to claim 3, wherein the movable stand is provided with a height adjustment mechanism that allows the stand to be periodically moved up and down by operating in synchronization with the rotation of each pair of forming rolls. Continuous cold roll forming equipment. 5. The continuous cold roll forming apparatus for curved bumpers according to claim 4, wherein the height adjustment mechanism includes a cam that rotates in synchronization with each pair of forming rolls to move the movable stand up and down.