JPH11188426A - Channel member roll forming - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve processing accuracy by restraining a divergent deformation due to a spring back at an end portion of the channel member in its delivery direction when the channel member is manufactured by a roll forming method with a steel plate as a raw material plate. SOLUTION: At the end portion S1 out of the raw material plate S, in a delivery direction towards a pair of processing rolls, and a portion along a folding line 15, slits 16 are formed in a way to extend closely and along the folding line 15. Since a folding strength is reduced at the slits 16 positions, a plastic deformation degree of the raw material S to be made with the pair of the last step processing rolls at its end potion S1 is strengthened. Thereby, a spring-back is rarely generated even when the raw material S passes through the last stage pair of processing rolls R3, resulting in an improvement of processing accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a channel-shaped channel-shaped member having a C-shaped cross section by roll forming.

[0002]

2. Description of the Related Art FIGS. 4 and 5 show the principle of cold roll forming using a steel plate as a raw material. FIG. 4 (A) is a diagram showing a bending process of the material plate S, FIG. 4 (B) is a diagram showing a partially extracted bending process by a roll pair, FIG. 4 (A) is a schematic side view of a forming process, and FIG. (B) is a plan view showing the principle of the molding step.

In FIG. 4 (A), a rectangular plate comprising a bottom plate 1, left and right side plates 2 connected thereto, a horizontal piece 3 connected to the tip of the side plate 2, and a lip 4 connected to the tip of the horizontal piece 3 is shown. The step of molding (manufacturing) the channel-shaped member 5 is shown. On the other hand, the figure
FIG. 4 (B) shows an outline of a specific bending process of the channel-shaped member 5 having the C-shaped cross section without the lip 4. As shown in FIG. 4, in the process of passing the strip-shaped raw material sheet S through a group of processing rolls formed by arranging a pair of upper and lower processing rolls R1, R2, R3 in parallel,
As shown in FIG. 3, first, the horizontal piece 3 is bent by several stages of processing roll pairs R1, and then several stages of processing roll pairs are formed.
It is manufactured through a process of bending the side plate 2 at R1, R2, and R3.

[0004] As shown in FIG.
The groove-shaped member 5 that has passed through R3 is inherited by the guide roll pair R4, and twisting and warping are corrected. On the other hand, there is a type shown in FIG. 6 as a display shelf used in a store or the like. That is, the display shelf 6 has a receiving member 10 provided on the inner surface of the underframe 7 by inserting the lower end of the column 9 having a C-shaped cross section into a square hole 8 formed in an underframe 7 having a U-shaped cross section. The column 9 is attached to the underframe 7 by fitting the lower end of the column 9 to
A framework is formed by fixing a top plate 11 to the upper end of the support 9 with screws 12. As shown in FIG. 7 (A), a large number of slots 13 are provided on the side surface of the support 9 at appropriate intervals, and a shelf (not shown) is supported by support claws fitted into the slots 13. Support height adjustable.

The columns 9 for the display shelves 6 are also shown in FIGS.
In this case, an intermediate member that is much longer than the length of the column 9 is manufactured and cut to form the column 9, and FIG. As shown, the material plate S is cut in advance to the length of the support 9,
There are two methods, that is, this is passed through a pair of processing rolls R1, R2, and R3 and bent into a groove shape. (It is the same in both cases that a slot 13 or the like is previously formed in the material plate S by pressing. is there).

In the former method, in which a long product is manufactured and then cut, the cutting must be performed by a cutting process such as a gut grinder or a sawing machine. In contrast to the latter method, which has the disadvantage of being large and large, the latter method of cutting into a predetermined length in advance and then bending it uses a material plate S cut by pressing. Therefore, there is an advantage that the manufacturing efficiency is good as a whole and that a large-scale apparatus is not required, and the method is particularly suitable for multi-kind small-quantity production.

[0007]

As described above, the method of using a fixed-size material plate has excellent advantages, but has a problem that the processing accuracy at both ends is not always good. This will be described below with reference to FIGS. 5, 7, and 8. That is, the leading end of the material plate S is formed by a pair of processing rolls R1, R2,
Since it is forcibly fed into R3 sequentially, it collides strongly with the pair of processing rolls R1, R2, R3, and therefore, a large external force acts on the tip of the material plate S and plastic deformation progresses excessively. Therefore, as shown in FIG. 9 (B), the tip 5a of the channel-shaped member 5 which is directed in the feed direction (the direction B in FIG. 5) in the manufacturing process is such that the side plate 2 falls down inward. It takes the form of

On the other hand, the rear end portion (end portion) 5b of the groove-shaped member 5 in the feed direction is bent at the final-stage working roll pair R3 to form the second-last working roll pair.
In order to bend in a state where the constraint by R2 is released,
At the same time as separating from the processing roll pair R3 in the final stage, the side plate 2 tends to open outwardly as shown in FIG.

For example, in the case of the groove member 5 of 40 mm square, the dimensional error of the front end portion 5a is minus 0.5 mm, while the rear end portion gradually expands in a range of about 80 to 100 mm from the end, and the rear end gradually increases. Was about plus 3 mm (the pitch P between the roll pairs R1, R2, R3, R4 shown in FIG. 8).
Is about 375 mm). For this reason, as shown in FIG. 5, when the channel-shaped member 5 is used as the support 9 of the display shelf 6 and the terminal 5b in the feed direction is used upward, the side plates 2 are open to each other. There is a problem that a gap is left between the adjacent top plates 11.

In the case of a column 9 (channel member 5) of 40 mm square,
If the dimensional error is plus or minus 1 mm, the error can be absorbed by the clearance between the screw 12 and the screw hole, etc.If the dimensional error can be reduced to that extent, the value of the fixed size roll forming method will be greatly enhanced, The quality of the channel member can be improved. For this reason, a roll forming method with high processing accuracy has been demanded.

An object of the present invention is to meet this demand.

[0012]

SUMMARY OF THE INVENTION The present inventor has proposed that at least a strip-shaped metal material plate be bent along a fold line by sequentially passing between a plurality of roll pairs arranged in parallel. We researched a method of forming into a grooved member with one bent part, and as a result, at the end part of the material plate facing the feed direction to the roll pair and the part along the fold line,
The processing accuracy can be improved by forming in advance a bending strength reduction portion such as a slit extending along the fold line or a small hole scattered along the fold line.

Here, as the bending strength reducing portion, a straight or perforated cutting line may be used in addition to the slits and small holes. Further, a portion along the fold line may be crushed into a thin shape and processed.

[0014]

As described above, the bent portion of the groove-shaped member spreads at the terminal end in the feed direction and is freely used because the restraint by the second last working roll pair is released. This is due to the springback caused by processing only with the pair of processing rolls. In this case, the degree of springback is proportional to the bending strength of the blank.

[0015] In this respect, when the configuration is made as in the present invention, due to the presence of the bending strength reducing portion such as the slit, the springback at the end portion in the feed direction can be remarkably suppressed. Experiments have shown that 40
The dimensional error could be suppressed to within plus 1 mm with the mm square channel member). Therefore, according to the present invention, even when the material plate is cut into a predetermined size in advance and roll-formed, the processing accuracy can be improved. The quality of the article can be improved.

Although the present invention is suitable for a roll cutting method of a fixed size cutting method, the present invention can also be used for a roll forming method of cutting after forming, and also in this case, what has conventionally been discarded is used. It is significant because it can be used.

[0017]

Next, an embodiment of the present invention will be described mainly with reference to FIGS. The present embodiment is a groove-shaped member used for the column 9 of the display shelf 6 described in the section of the prior art.
FIG. 1 (A) shows a case where the method is applied to the manufacturing method of FIG.
FIG. 1B is a partial perspective view of a manufactured 14 (post 9) used in the method of the embodiment, and includes a bottom plate 14a, left and right side plates 14b, and a horizontal piece 14c. In FIG. 1 (A),
The channel-shaped member 14 is shown upside down from the state used as the column 9.

3 and FIG. 4 is the same as the conventional method, and the material plate S shown in FIG. 1B is passed through the same roll pair R1, R2, R3 as the conventional one to form the groove. The member 14 is manufactured. In this case, according to the present invention, as an example of the bending strength reducing means, at the end S1 of the material plate S and outside the two fold lines 15 which become the bent portions 14 between the bottom plate 14a and the side plate 14b of the channel member 14. A slit 16 extending in the vicinity of the fold line 15 is formed in advance, and this material plate S is passed through the pair of rolls R1, R2, R3, and R4 in FIG. .

Then, due to the presence of the slit 16, the fold line
Since the bending strength in the vicinity of 15 is low, when bending by the pressing action of the pair of processing rolls R3 in the final stage, it is almost in a plastically deformed state due to stress concentration. As shown in FIG. 2, the dimensional accuracy can be remarkably improved (in the experiment of the present inventors, the dimensional error could be suppressed within plus 1 mm). Therefore, as shown in FIG.
, No gap is formed between the adjacent top plates 11.

The slit 16 may be pressed at the same time as the slot 13 or before or after the slot 13.
Even if 16 is provided, the cost hardly increases. Slit 16
In the case of the position and the length of the column 9 in the case of manufacturing the column 9 of 40 mm square, the distance L1 from the end face of the material plate S is about 20 mm,
The length L2 of the slit 16 was preferably about 60 mm.
If the distance L1 from the end face of the material plate S is too short, or if the length L2 of the slit 16 is too long, the strength of the column 9 is undesirably reduced.

In FIG. 3, a plurality of long holes 17 are formed in series at the end of the blank S as a means for lowering the bending strength. A large number of small-diameter round holes or square holes may be formed in rows.
Further, a slit 16 or the like may be formed in a portion corresponding to the bottom plate 14a. Further, these slits 16 and long holes 17 may be used for some purpose. Although the above embodiment was applied to the manufacture of a rectangular channel member, the present invention
U-shaped and L-shaped cross-sections, or U-shaped cross-section members,
The present invention can be applied to the manufacture of channel-shaped members having various shapes. It goes without saying that the intended use of the manufactured channel-shaped member does not matter.

[Brief description of the drawings]

FIG. 1A is a plan view of a material plate used in a first embodiment, and FIG. 1B is a perspective view of a manufactured channel member (post).

FIG. 2 is a partial plan view of the manufactured channel member.

FIG. 3 is a diagram showing a first embodiment.

FIG. 4 is a view showing the principle of a roll forming method.

FIG. 5 is a view showing the principle of a roll forming method.

FIG. 6 is an exploded perspective view of a frame of the display shelf.

FIG. 7 is a diagram showing a conventional technique.

FIG. 8 is a diagram showing a problem of the related art.

FIG. 9 is a view showing a problem of the related art, (A) is a plan view,
(B) is a BB view of (A), and (C) is a CC view of (A).

[Explanation of symbols]

 R1, R2, R3 Processing roll pair R4 Guide roll pair S Material plate 6 Display shelf 9 Prop 14 Groove 14d Bend 15 Fold line 16 Slit 17 Slot 17

Claims (2)

[Claims] 1. A grooved shape provided with at least one bent portion by bending a strip-shaped metal material plate along a fold line by sequentially passing between a plurality of roll pairs arranged in parallel. It is a method of forming into a member, a point along a fold line or a slit extending along the fold line, at a portion along the fold line at a terminal end of the material plate facing the feed direction to the roll pair. A method for forming a groove-shaped member according to claim 1, characterized in that a bending strength reduction portion such as an existing small hole is formed in advance, and then the material plate is passed through the plurality of roll pairs. 2. The method according to claim 1, wherein the channel member is
A rectangular member having a C-shaped cross section used for furniture such as a display shelf or a partition, and the material plate is cut into a length of a groove-shaped member in advance, and then the material plate is sequentially cut into a plurality of roll pairs. A roll forming method for a channel-shaped member, characterized by passing through.