JPS633691B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a continuous cold roll forming method and apparatus for forming a section steel having a groove-like cross section, such as a channel steel, a channel steel with a lip, a hat section steel, and a U section steel. .

Among the section steels with groove-like cross sections, U-section steels are particularly
In recent years, with the construction of large bridges, concrete deck slabs have been replaced by steel deck slabs, which are lighter in weight and have superior strength. I'm getting old.

As shown in Fig. 1, the steel deck plate is composed of a deck plate 1, vertical ribs 2, and horizontal ribs 3.
In addition to the steel plate originally shown, there are a valve plate 2a and a scalene angle 2 as shown in Fig. 2 a and b.
Previously, vertical ribs with an open cross section were used, but with recent advances in design technology and construction technology, the vertical rib with an open cross section has been used.
As shown in the figure, closed cross-section vertical ribs made of U-shaped steel 4 have come to be used frequently.

(1) The rigidity of the ribs is large, the distance between the horizontal ribs is large, the load distribution is good, and the weight of the steel deck can be reduced.

(2) Since it has a closed cross section, the inside is sealed, which is good for corrosion protection.

(3) The length of welding with the deck plate is approximately half that of the vertical rib on the open section, resulting in low welding distortion and high welding efficiency.

(4) There are no shape irregularities such as rib collapse, and the design shape is easy to determine.

By the way, U-shaped steel 4 has traditionally been manufactured by press forming, but press forming does not have stable product accuracy.
The variation from piece to piece was large, and there was also a limit to the length of the product, resulting in low efficiency and poor productivity.

In order to achieve mass production while ensuring the quality of the U-shaped steel 4, roll forming is performed, but in the conventional method of continuously forming the U-shaped steel 4 from the strip through multiple roll stands, the U-shaped steel 4 is As the size of the U-shaped steel 4 increases, the size of the roll increases, and problems arise in the shape and size accuracy of the U-shaped steel 4, such as warping and twisting. The biggest manufacturing problem in terms of shape and size accuracy is the top width A of the cutting edge, as shown in Figure 4.
This is a variation in dimensions. This is a deformation near the cutting opening where the residual stress of the cold roll formed product is released during cutting, and as shown in Figure 5, the flange 4a on the downstream side of the forming of the U-shaped steel 4 opens, and the flange on the upstream side opens. 4
a′ is closed.

In order to solve this problem, recently a pair of left and right outer flat rolls were installed between the roll stands immediately before the completion of forming, as shown in FIG. 5 and a pair of left and right inner flat rolls 6 with a slight interval in the longitudinal direction, and the steel strip 10
is roll-formed into U-shaped steel 4.

The plate thickness 6 formed by this roll forming method
mm, corner angle 60 degrees, height of flange 4a 220
For U-shaped steel 4, which has a low top width of 300 mm, the variation in the top width of the cut end (300 mm) was significantly reduced, and a sufficient effect was obtained.
Corner angle 60 degrees, height of flange 4a 260 mm
When the U-shaped steel 4 was formed, undulations occurred in the edge portion 4b as shown in FIG. The corner portion 4c, which is the base of the tube, was significantly thinned.

Therefore, the present inventors first investigated the cause of the waviness of the edge portion 4b of the flange 4a of the U-shaped steel 4 obtained by the above-mentioned roll forming method and the cause of the waviness of the flange 4.
A study was conducted to find out the cause of the significant thinning of the corner portion 4c of A.

Flange 4 of U-shaped steel 4 that is generally roll-formed
The edge portion 4b of a is susceptible to elongation strain in the longitudinal direction, so-called waviness, because the flange-equivalent portion 10 of the steel strip 10 is in the process of entering the roll gap.
When the edge a rises, that is, the torsional deformation around the longitudinal axis is applied to the flange-equivalent portion 10a as shown in FIG. This is due to the accumulation of elongation deformation due to longitudinal bending and unbending deformation under the action of the resulting longitudinal tension.

The shear strain due to torsional deformation around the longitudinal axis applied to the flange-equivalent portion 10a of the steel strip 10 increases monotonically from the base of the flange-equivalent portion 10a toward the edge, so its influence is greater at the edge. Although it is often thought that this edge is the largest, in reality, during the process of entering the roll gap, this edge is subjected to severe longitudinal elongation/shrinkage deformation, longitudinal bending/unbending deformation, and as a result, the above-mentioned Most of the residual shear stress due to shear deformation is canceled out. This means that "the influence of residual stress due to plastic strain applied from one direction is canceled by plastic strain applied from another direction."
This is a well-known fact. Therefore, U-shaped steel 4
The residual shear stress due to the above-mentioned shear deformation, which causes a change in the width A dimension above the cut end, is at its maximum near the center of the flange-equivalent portion 10a of the steel strip 10.

However, when applying reverse torsional deformation around the longitudinal axis to the flange-equivalent portion 10a in order to remove the residual shear stress that causes deformation near the cut end of the U-beam 4, the pair of left and right inner flats are When unnecessary torsional deformation is applied to the edge portion by the troll 6, elongation deformation of the flange-corresponding portion is induced due to deformation behavior similar to that described above, resulting in promotion of waviness and other shape defects. Therefore, the conventional roll forming method proposed to solve the deformation near the cutting edge is
As a result, the edge portions are subjected to stronger torsional deformation, and it is clear that this method cannot be used for forming U-shaped steel 4 with a high flange 4a.

Further, in the conventional roll forming method described above, rapid pushing and pushing back is applied to the flange-corresponding part of the steel strip, so the corner part 4 which is the base of the flange 4a
It is also clear that the corner portion 4c is significantly thinned due to the large elongation due to the folding of the corner portion 4c.

The present invention provides an edge portion 4b of a flange 4a of a U-shaped steel 4 obtained by the conventional roll forming method described above.
This was done by focusing on the cause of waviness and the cause of thinning of the corner part 4c of the flange 4a, and the above-mentioned problem that causes deformation near the cut end of various shaped steels with grooved cross sections, including the U-shaped steel 4. The maximum reverse torsional deformation is applied near the center of the flange where the residual shear stress due to the shear deformation of The present invention provides a continuous cold roll forming method for channel steel and an apparatus therefor, which suppresses thinning by eliminating folding of corner portions, which are the bases of flanges.

The method and apparatus for continuous cold roll forming of channel steel according to the present invention will be described below with reference to the case of forming U-shaped steel. First, an example of a continuous cold roll forming apparatus for carrying out this method will be explained with reference to FIGS. 9a and 9b.
In the meantime, it is successively formed and then
When forming the section steel 4 is completed, a mechanism 11 for imparting reverse torsional deformation around the longitudinal axis to the flange-equivalent portion 10a of the steel strip 10 is incorporated in the roll stand D between the roll stands C and E. . 1
2 and 13 are pinch rolls installed upstream of roll stand A; 14 and 15 are forming rolls installed in roll stand A; 16 and 17 are forming rolls installed in roll stand B; and 18 and 19 are roll stand C. Forming rolls 20 and 21 incorporated in the roll stand E are forming rolls 20 and 21 incorporated in the roll stand E. Reverse torsional deformation imparting mechanism 11 of the roll stand D
is a pair of left and right flat rolls 22, which are vertically pivoted and tilted toward the outer surface of the flange-equivalent portion 10a of the steel strip 10, with a slight distance in the longitudinal direction between roll stands C and D; The flat rolls 22 consist of a pair of left and right large drum rolls 23 which are vertically supported, and the flat rolls 22 are used to roll the steel strip 1 as shown in FIG. 10a.
The drum-shaped roll 23 is arranged so as to push the upper half of the flange-equivalent part 10a of the steel strip 10 inward by a certain amount, and the large drum-shaped roll 23 pushes the flange-equivalent part 1 of the steel strip 10 as shown in FIG. 10b.
They are arranged so as to push back the vicinity of the center of the steel strip 0a to the outside, and are overlapped most deeply at a position near the center of the flange-equivalent portion 10a of the steel strip 10 when viewed in the longitudinal direction of the steel strip 10.

The pair of left and right outer flat rolls 22 are
The lower ends of the respective shafts 22a are supported by rotary/fixed bearings 26 on the base 25a of the outer frame 25 provided on the pedestal 24, and the base 25a is moved in the left-right direction by rotation of a moving screw 27 coupled to the outer frame 25. It's becoming like that. Therefore, the support point at the lower end of the shaft 22a of the flat roll 22 can be moved. The upper end of the shaft 22a of the flat roll 22 is connected to a guide 2 horizontally fixed to the upper part of the outer frame 25.
It is supported by a rotation/movement bearing 29 which is provided so as to be movable along the axis 8, and the rotation/movement bearing 29 is adapted to move in the left-right direction by the rotation of the movement screw 30. Therefore, the shaft 22a of the flat roll 22
The support point at the top of the can be moved.

In other words, the angle and distance of the pair of left and right outer flat rolls 22 can be adjusted by moving the support points at the upper and lower ends of the shaft 22a.

The pair of left and right inner large drum-shaped rolls 23 have their shafts 23a at the upper ends of which are connected to guides 32 that are horizontally fixed between left and right fixed frames 31 provided on the pedestal 24.
Rotating/moving bearing 3 provided movably along
3, and the rotary/moveable bearing 33 is adapted to move in the left-right direction by rotation of a moving screw 34. Therefore, the support point at the upper end of the shaft 23a of the drum-shaped roll 23 can be moved. The lower end of the shaft 23a of each drum-shaped roll 23 is connected to a plate 3 suspended below the center of the guide 32 between the left and right fixed frames 31.
The rotary/moving bearings 35 are supported by rotary/moving bearings 35 that are movable in the left/right direction along the left and right guides 39 on the plate 38 .
It is adapted to move outward by rotation of jack bolts 37 screwed into both left and right sides of a jack receiver 36 fixedly installed in the upper center. Therefore, the support point at the lower end of the shaft 23a of the large drum-shaped roll 23 can be moved.

In other words, the pair of left and right inner large drum-shaped rolls 23 are
The angle and spacing can be adjusted by moving the support points at the upper and lower ends of the shaft 23a.

Next, the continuous cold roll forming method of the present invention for forming the U-shaped steel 4 using the continuous cold roll forming apparatus of the present invention configured as described above will be explained.

As shown in FIGS. 9a and 9b, the steel strip 10 passes between the pinch rolls 12 and 13, and then passes through each forming roll rotated by a drive device built into the roll forming device, and is successively formed. It becomes U-shaped steel 4. That is, the forming rolls 14 and 15 of roll stand A, and the forming roll 1 of roll stand B.
6 and 17, the flange-equivalent portions 10a on both sides of the steel strip 10 are bent symmetrically upward as shown in FIG. As shown, the flange-equivalent portions 10a on both sides are further symmetrically bent upward. When passing between the pair of left and right outer flat rolls 22 of the roll stand D, the upper halves of the flange-equivalent parts 10a on both sides are pushed inward by the flat rolls 22, as shown in FIGS. 10a and 11c. After passing between the flat rolls 22, the torsional deformation is applied so as to restore the spring bag of torsional deformation around the longitudinal axis applied by the upstream forming rolls, and immediately after passing between the flat rolls 22, the left and right inner large drum shapes are formed. It passes outside the roll 23. The flange-equivalent portions 10a on both sides of the steel strip 10 passing outside the large drum-shaped roll 23 are the first
As shown in FIG. 1d, the vicinity of the central portion is pushed back outward by the large drum-shaped roll 23, and reverse deformation is applied around the longitudinal axis. At this time, the large drum-shaped roll 23 does not come into contact with the edge and lower half of the flange equivalent part 10a at all as shown in FIG. and becomes weaker toward the edges.

In this way, residual shear stress due to torsional deformation around the longitudinal axis applied to the flange-corresponding portion 10a by the forming roll on the upstream side of the reverse torsional deformation imparting mechanism 11 is eliminated.

The steel strip 10 that has passed through the outside of the large drum-shaped roll 23 is then transferred to the forming rolls 20, 21 of the roll stand E.
and is finished formed into a U-shaped steel 4 as shown in FIG. 11e. The U-shaped steel 4 thus obtained had no longitudinal undulations in the edge portion 4b of the flange 4a and was straight. Further, there was extremely little thinning of the corner portion 4c, which is the base of the flange 4a.

Steel strip 10 by the above-mentioned reverse torsion deformation imparting mechanism 11
The processing conditions for reverse torsional deformation of the flange-equivalent portion 10a will be described below.

As shown in Fig. 12, the steel strip 10 is
The maximum value of shear strain due to torsional deformation around the longitudinal axis which the flange equivalent portion 10a receives is approximately expressed by the following equation.

(γ ₁ ) _nax ≒ β ^*・W・(Δθi) _nax /L (1) However, W: Width dimension of the flange equivalent part β ^* : Coefficient representing the position where maximum residual shear stress occurs = 0.6 to 0.8 (Δθi) _nax : 1 Maximum value of the bending angle increment of the flange-equivalent portion per forming stand L: Actual deformation area length = α・D D: Maximum diameter α of the flange-equivalent portion of the forming roll: Coefficient 0.5 to 1.5 Outside of the reverse twisting deformation imparting mechanism 11 The maximum value of torsional deformation applied to the flange equivalent portion 10a by the flat roll 22 is approximately given by the following equation.

(γ ₃ ) _nax ≒β ^*・W・(Δθi) _nax /d = β ^*・W・δ _nax /β ^*・W/d=δ _nax /d (2) where β ^*・W: maximum due to flat roll Indentation position δ _nax : Maximum indentation amount by the flat roll d : Distance between the flat roll and the drum-shaped roll in the longitudinal direction The stress-strain characteristics regarding shear deformation of the steel strip 10 are expressed by the following equation.

If γ=F・γ ⁿ (3), the flange equivalent part 10 is formed by the forming roll.
The maximum value of the shear stress generated due to the torsional deformation around the longitudinal axis applied to a is given by the following equation.

(γ ₁ ) _nax =F・(γ ₁ ) ⁿ _nax (4) When this shear deformation undergoes return deformation and becomes γ ₁ →0, the shear stress is expressed by the following equation, ignoring the Bauschinger effect.

(γ ₁ ) γ ₁ →0 = F {2 (γ ₁ ) _nax −2F/G (γ ₁ ) _nax } ⁿ (5) Reverse torsional deformation is applied to this stress state, and as a result of subsequent elastic recovery, residual stress In order to become 0, the shear strain (γ ₃ ) _nax of reverse torsional deformation must satisfy the following relationship.

−G・(γ ₃ ) _nax = −F・{2(γ ₁ ) _nax −2F/G(γ ₁ ) _nax +(γ ₃ ) _nax } ⁿ = −F・(γ ₁ ) ⁿ _nax {2−2F /G+(γ ₃ ) _nax /(
γ ₁ ) _nax } ⁿ (6) Here, since F/G≪1, (γ ₃ ) _nax / (γ ₁ ) _nax ≪1, we introduce an approximate expression and get G(γ ₃ ) _nax ≒2F・(γ ₁ ) ⁿ _nax {1+1/2n(γ ₃ ) _nax /(γ ₁
) _nax }(7) Therefore, we obtain the following equation.

(γ ₃ ) _nax {G−F・n・(γ ₁ ) ⁿ⁻¹ _nax } =2F(γ ₁ ) ⁿ _nax (8) Therefore By substituting the calculation formulas for (γ ₃ ) _nax and (γ ₁ ) _nax into the above equation, the processing conditions required to remove the influence of residual shear stress are shown by the following equation.

If we pay attention to G≫Fn(γ ₁ ) ⁿ − ¹ _nax in equation (9), we get (
Ten)
The formula can be further simplified and shown as follows.

δ _nax /d≧2F/G{β ^*・W(Δθi) _nax /L} ⁿ (
11) The above relational expression has been considered by considering the shear stress generated in the central part (middle part) of the flange equivalent part 10a as a representative value, but the influence of the shear stress generated in other parts is a matter of the strain range mentioned above. It can be considered as
This determines the minimum amount of reverse torsional deformation that should be applied.

Now, as mentioned above, the U-shaped steel 4 formed by the continuous cold roll forming method of the present invention is then cut into a cutting machine (not shown) installed downstream of the roll stand E.
When the sample was cut to a fixed size, there was very little deformation near the cut opening. This is just steel strip 1
The maximum reverse torsional deformation around the longitudinal axis is applied to the vicinity of the center of the flange equivalent part 10a of No. This is because the residual shear stress caused by Actual top width 320mm, bottom width 204.4mm, flange height 260mm, board thickness 6mm, corner radius 30
mm U-shaped steel 4 was manufactured by the continuous cold roll forming method of the present invention and the conventional continuous cold roll forming method, and the upper width A dimension near the cutting opening when these were cut to a fixed size was The measured results are shown in the graph of FIG. As is clear from this graph, the deformation near the cut end of the U-shaped steel 4 obtained by the forming method of the present invention is compared to the deformation near the cut end of the U-shaped steel 4 obtained by the conventional forming method. It can be seen that there are extremely few amounts on both the upstream and downstream sides.

In the continuous cold roll forming apparatus of the above embodiment, the pair of left and right outer flat rolls 22 in the reverse torsional deformation imparting mechanism 11 of the roll stand D are the first
As shown in Figure 4 a and b, a large drum-shaped roll 23'
It may be replaced with In this case, the large drum-shaped rolls 23' are arranged so as to push the vicinity of the center of the flange-corresponding portion 10a of the steel strip 10 inward by a certain amount as shown in the figure, and the pair of left and right inner large drum-shaped rolls 23'
3 overlap most deeply at a position near the center of the flange-equivalent portion 10a of the steel strip 10 when viewed in the longitudinal direction of the steel strip 10.

When the steel strip 10 is formed into the U-shaped steel 4 by the continuous cold roll forming apparatus equipped with the reverse torsional deformation imparting mechanism 11 having such a configuration, the steel strip 10 passes through the forming rolls 18 and 19 of the roll stand C and is shown in FIG. 15a. When the steel strip 10 formed as shown passes through the pair of left and right outer drum rolls 23' of the roll stand D, the first
As shown in Fig. 5b, the vicinity of the center of the flange-equivalent portions 1a on both sides is pushed inward by the large drum-shaped roll 23', and the spring bag due to torsional deformation around the longitudinal axis applied by the upstream forming roll is removed. Torsional deformation is applied so that it returns to its original state. Immediately after passing between the large drum-shaped rolls 23', the outside of the pair of left and right inner large drum-shaped rolls 23 is passed, and as shown in FIG. It is pushed back outwards to impart a reverse torsional deformation about the longitudinal axis. In this way, residual shear stress due to torsional deformation around the longitudinal axis applied to the flange-corresponding portion 10a by the forming roll on the upstream side of the reverse torsional deformation imparting mechanism 11 is eliminated. Next, the steel strip 10 that has passed through the outside of the large drum-shaped roll 23 passes through the forming rolls 20 and 21 of the roll stand E, and is finished formed into a U-shaped steel 4 as shown in FIG. The edge portion 4b of the flange 4a had no longitudinal undulations and was straight. Further, there was extremely little thinning of the corner portion 4c, which is the base of the flange 4a. Then, when this U-shaped steel 4 was cut to size,
The deformation in the vicinity of the cutting opening was extremely small as in the case of the previous example.

In the continuous cold roll forming apparatus of the present invention, the left and right pair of outer flat rolls 22 or large drum-shaped rolls 23' and the left and right pair of inner large drum-shaped rolls 23 of the reverse torsional deformation imparting mechanism 11 have their respective axes. Since the upper and lower ends of the U-shaped steel 4 can be rotated and moved, the flange height, angle, and
If the dimensions and shape of the plate change, such as the plate thickness, it is sufficient to adjust the angle and horizontal spacing of the flat rolls or large drum-shaped rolls. The amount of weight viewed from the longitudinal direction may be adjusted as appropriate.

Furthermore, in the above-described embodiments of the present invention, a case was explained in which a U-shaped steel was formed, but the invention is not limited to this. When forming steel, residual shear stress can be eliminated by applying reverse torsional deformation near the center of the flange of the shaped steel just before the forming is completed, in the same way as described above.

As described in detail above, the continuous cold roll forming method for channel steel of the present invention is characterized in that the torsion around the longitudinal axis is applied by an upstream forming roll to the vicinity of the center of the flange of the channel steel immediately before the completion of forming. After applying torsional deformation to restore the spring bug of deformation, reverse torsional deformation around the longitudinal axis is immediately applied to eliminate residual shear stress due to torsional deformation, so the flange edge of the resulting channel steel Waviness does not occur in the longitudinal direction, and deformation near the cut end is eliminated when cut to size. Further, since the corner portion, which is the base of the flange, is not folded back after the flange is bent and formed by the forming rolls, there is an excellent effect that thinning is significantly suppressed.

Further, according to the continuous cold roll forming apparatus for channel steel of the present invention, not only can the roll forming method described above be carried out smoothly and easily, but also reverse torsional deformation can be imparted to the vicinity of the center of the flange of the channel steel. The angle and lateral spacing of the pair of left and right outer flat rolls or large drum-shaped rolls and the pair of left and right inner large drum-shaped rolls of the mechanism can be adjusted, so the dimensions and shape of the channel steel to be formed can be changed. It has the excellent effect of being able to cope with any situation.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a conventional steel deck, FIGS. 2 a and b are views showing other examples of vertical ribs in the steel deck, and FIG. 3 is a perspective view showing a current steel deck. Fourth
Figure 5 is a front view of the U-shaped steel, Figure 5 shows the deformation near the cutting opening of the U-shaped steel, and Figure 6 shows the mechanism for suppressing deformation near the cutting opening in the conventional continuous cold roll forming method. Figure 7 is a perspective view showing the waviness of the edge of the flange of a U-shaped steel obtained by the conventional continuous cold roll forming method, and Figure 8 is a continuous cold roll forming of a U-shaped steel from a strip steel. Figures 9a and 9b are a schematic plan view and a schematic side view of the continuous cold roll forming apparatus for channel steel according to the present invention. Figures 10a and 10b are an enlarged cross-sectional view taken along the line I--I of Figure 9b, and an enlarged cross-sectional view taken along the line I
Figure 1 a, b, c, d, and e correspond to E in Figure 9 a.
Cross-sectional views showing the state of the U-shaped steel during and after forming at the A, Ro-Ro, Ha-Ha, Ni-Ni, and Ho-Ho wires. Figure 12 shows the flange portion of the steel strip in the process of entering the roll gap. Fig. 13 is an explanatory diagram of torsional deformation and return deformation around the longitudinal axis of , and Fig. 13 is a measurement of the upper width A dimension near the cut end of U-shaped steel obtained by the roll forming method of the present invention and the conventional roll forming method. Graphs showing the results, FIGS. 14a and 14b are a schematic plan view and a schematic side view showing the main parts of another example of the continuous cold roll forming apparatus for channel steel according to the present invention, and FIGS. 15a and 15b are graphs showing the results.
14c and d are cross-sectional views showing the state of the U-shaped steel during and after forming along the Ro-Ro, Ha-Ha, Ni-Ni, and Ho-Ho lines in FIG. 14a. 4... U-shaped steel, 4a... U-shaped steel flange, 4
b...Edge part of flange, 4c... Corner part of flange, 10... Steel band, 10a... Part corresponding to flange of steel band, 11... Reverse torsional deformation imparting mechanism, 1
2, 13...pinch roll, 14, 15, 16,
17, 18, 19, 20, 21... forming roll,
22... Flat roll, 23, 23'... Drum-shaped roll, 24... Frame, 25... Outer frame, 25a... Base, 26... Rotating/fixed bearing, 27... Moving screw, 28... Guide , 29...
...Rotating/moving bearing, 30... Moving screw, 31...
Fixed frame, 32... Guide, 33... Rotating
Moving bearing, 34... Moving screw, 35... Rotating/moving bearing, 36... Jacket receiver, 37... Jacket bolt, 38... Plate, 39... Guide,
A, B, C, D, E... Roll stand.

Claims (1)

[Claims] 1. When forming a section steel with a groove-like cross section from a steel strip continuously through a large number of roll stands, between the roll stands just before the end of forming, the steel strip is After applying torsional deformation to restore the spring bag of torsional deformation around the longitudinal axis applied to the flange-equivalent part of the steel strip, immediately tighten the flange base and edge at a position near the center of the flange-equivalent part of the steel strip. It is characterized by applying reverse torsional deformation around the longitudinal axis such that it becomes weaker toward the end to eliminate residual shear stress due to torsional deformation around the longitudinal axis applied to the flange-corresponding part. Continuous cold roll forming method for channel steel. 2. A large number of roll stands each having a pair of upper and lower pinch rolls, a pair of upper and lower forming rolls disposed downstream of the pinch rolls at a required interval, and a roll stand disposed between the last roll stand and the roll stand immediately before it. The reverse torsional deformation imparting mechanism comprises a pair of left and right rolls or drum-shaped rollers located on the outer surface side of the flange-equivalent portion of the steel strip passing through the portion and pivoted in the vertical direction. It consists of a roll and a pair of left and right large drum-shaped rolls that are spaced downstream from the left and right pair of rolls or a pair of left and right large drum-shaped rolls that are located on the inner surface of the flange-equivalent part of the steel band and are pivotally supported in the vertical direction. , and so that the roll or large drum-shaped roll on the outer surface side of the flange-equivalent portion of the steel band and the large drum-shaped roll on the inner surface side overlap most deeply at a position near the center of the flange-equivalent portion of the steel band when viewed from the longitudinal direction of the steel band. A continuous cold roll forming device for channel steel, characterized in that: 3. The upper and lower ends of each axis of the pair of left and right rolls or large drum-shaped rolls located on the outer surface of the flange-equivalent part of the steel band and the pair of left and right large drum-shaped rolls located on the inner surface are rotatable and movable. A continuous cold roll forming apparatus for channel steel according to claim 2.