JPH0112569B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pipe forming apparatus for forming a metal plate into a desired curvature.

The conventional equipment for manufacturing electric resistance welded pipes is shown in Figures 1 to 4.
As shown in the figure, a metal plate s unwound from a coil a is guided by guide rolls b, and a load is applied in the circumferential direction of the metal plate s by a vertical pipe forming device c to buckle it to a desired curvature. It is bent and formed, held by breakdown rolls d, pressed and bent to successively larger curvatures, formed into a complete tubular shape by fin pass rolls e, and the joints are welded by a welder f, as shown in Fig. 5. ERW tube g is manufactured.

Among such equipment, the vertical roll h of the pipe forming apparatus c has a flange i at the upper part and has a shape that gradually widens toward the lower part, and the metal plate s has both ends by the flanges i, i. It is buckled and bent while being pressed. However,
Since the vertical rolls h and h are preset, once the width is set, the metal plate s
The width cannot be changed during molding, and the housing supporting the vertical roll h undergoes elastic deformation due to reaction force. For this reason, depending on the material of the metal plate s, both ends of the metal plate s do not abut flatly as shown in FIG. After the metal plate s is partially concave and buckled, the metal plate s does not come into close contact with the roll surface and is left unfinished, which further exacerbates the defective shape.

On the other hand, the force with which the metal plate s is pinched by the breakdown roll d becomes excessive, so the breakdown roll d
A sag occurs on the end surface of the metal plate s after forming.

From the above, even if the joints shown in Fig. 7 A and B are welded and a product is manufactured under such conditions, the appearance will be poor.
Moreover, there were problems such as insufficient strength of the welded portion.

The present invention includes a flanged side roll that can freely tilt in the width direction of a metal plate, and an inner roll that presses the metal plate against the surface of the side roll, and the metal plate is sandwiched between the side roll and the inner roll. By applying a circumferential load to the end of the metal plate using the flange and applying buckling or constriction to the metal plate, the end face of the metal plate is prevented from being depressed or sagging, and the buckling position of the plate is created. This was done with the aim of preventing this from occurring and obtaining a product of good quality.

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

Housing 1 arranged on both sides of the metal plate s in the width direction
Hydraulic cylinders 2a and 2b whose axes extend in the width direction of the metal plate s are pivotally mounted above the housings 1a and 1b, and pins whose axes extend parallel to the direction of movement of the metal plate s are mounted at required positions on the housings 1a and 1b. Side rolls 4a and 4b are pivotally connected via rollers 3a and 3b, and the rod tips of the hydraulic cylinders 2a and 2b are pivotally connected to brackets 5a and 5b that project above the side rollers 4a and 4b. Side rolls 4a, 4b
has flanges 4a' and 4b' on its upper part, and its shape is drum-shaped. Further, it can be driven by a drive device (not shown).

A signal can be sent from the position or load setting device 6 of the fluid pressure cylinders 2a, 2b to the ratio calculators 7a, 7b, and the fluid pressure cylinders 2a, 2b
position detectors 8a, 8b or pressure detectors 9a, 9
The signal detected in step b can be transmitted to the comparator units 7a and 7b via the circuits 10a and 10b or the circuits 11a and 11b, and the circuits 10a, 11a, 10
Switches 13a and 13b for selectively selecting a circuit by means of levers 12a and 12b are disposed on the circuits 11a and 11b, and the gain setting device 1 is disposed on the circuits 11a and 11b.
Arithmetic unit 1 that obtains the gain set in 4a and 14b
5a, 15b are connected, and when the metal plate s meanderes, a signal from a left/right position correction setting device 21 that adjusts the stroke of the fluid pressure cylinders 2a, 2b according to the amount of meandering is sent to the comparison calculators 7a, 7b. The output signals of the comparators 7a and 7b can be sent to servo valves 16a and 16b that control the amount of oil to the hydraulic cylinders 2a and 2b.

An elevating frame 18 that can be raised and lowered by a suitable elevating device is attached to a frame 17 provided above the housing, and a metal plate s is held in the lower part of the elevating frame 18 in cooperation with the side rolls 4a and 4b. Inner roll 19 made possible
A and 19b are arranged in a freely drivable manner, and a drum-shaped breakdown roll 20 whose curvature is approximately the same as the curvature of the side rolls 4a and 4b is drivably arranged below the inner rolls 19a and 19b.

Next, the operation of the present invention will be explained.

For example, when controlling the molding process by the amount of rod protrusion of the fluid pressure cylinders 2a, 2b, the switches 13a, 13b are controlled by the levers 12a, 12b.
are connected to the circuits 10a and 10b, and the setter 6 sets the rod protrusion amount of the fluid pressure cylinders 2a and 2b to the comparators 7a and 7b. Comparison calculator 7a,
The rod protrusion amount signal set at 7b is sent to the servo valves 16a, 16b.
6b opens, pressure oil is sent to the hydraulic cylinders 2a, 2b, the rods of the hydraulic cylinders 2a, 2b move back and forth, and the side rolls 4a, 4b move against the pins 3a, 3.
Tilt with b as the fulcrum.

The rod protrusion amount of the fluid pressure cylinders 2a and 2b is
It is detected by the position detectors 8a and 8b, and the signals are fed back to the comparison calculators 7a and 7b.
If the feedback signal becomes equal to the signal set by the setting unit 6, the outputs from the comparators 7a and 7b become zero, so the servo valves 16a and 16
b is closed, and the rods of the hydraulic cylinders 2a, 2b are stopped. Therefore, the side rolls 4a and 4b also stop tilted at a predetermined angle. The lifting frame 18 is lowered by the lifting device, and the side roll 4
The gaps between a, 4b and inner rolls 19a, 19b are brought to a predetermined state.

The metal plate s is sandwiched between the side rolls 4a, 4b and the inner rolls 19a, 19b, and both ends of the metal plate s are brought into uniform contact with the flanges 4a', 4b'. Buckling bending is performed by a circumferential load of s. Therefore, both ends of the metal plate s do not dent or sag, and buckling occurs along the roll surface rather than as a finished product, resulting in a good shape after forming.

In the case where the metal plate s has meandered from side to side, both ends of the metal plate s do not come into uniform contact with the flanges 4a' and 4b', so the operator operates the setting device 21. Therefore, the setting signal is set in the comparison calculators 7a, 7b, and the setting signal is sent to the servo valves 16a, 16b, which open the servo valves 16a, 16b, thereby increasing the amount of protrusion of the fluid pressure cylinders 2a, 2b, in other words, the side roll. The inclination angles of 4a and 4b are adjusted so that both ends of the metal plate s uniformly abut against the flanges 4a' and 4b'. When the rods of the fluid pressure cylinders 2a, 2b move back and forth by a predetermined amount, the difference between the feedback signals from the position detectors 8a, 8b and the setting signal becomes zero, so the servo valves 16a, 16b are closed. In the case of position adjustment using the setting device 21, for example, if the rod of the hydraulic cylinder 2a protrudes, the hydraulic cylinder 2
The rod at b moves back by the same amount.

When controlling the molding process using the pressure or load of the fluid pressure cylinders 2a and 2b, the lever 12
The switches 13a and 13b are connected to the circuits 11a and 11b by the switches a and 12b, and the pressure of the pressure oil in the hydraulic cylinders 2a and 2b is set by the setting device 6 in the comparison calculators 7a and 7b. Comparison calculators 7a, 7b
The pressure signal set to servo valves 16a, 16
b, the servo valves 16a and 16b open, and pressure oil is sent to the hydraulic cylinders 2a and 2b, causing the rods of the hydraulic cylinders 2a and 2b to move forward and backward. When the pressure detected by the pressure detectors 9a, 9b becomes equal to the set pressure, the rods of the hydraulic cylinders 2a, 2b are stopped by feedback signals from the circuits 11a, 11b.

When forming the left and right sides with different pressures depending on the state of the metal plate s, the gain setting devices 14a, 1
In step 4b, gains are set in the arithmetic units 15a and 15b. Therefore, the output signals of the arithmetic units 15a and 15b are:
The signals from the pressure detectors 9a and 9b are multiplied by a gain, and the signals are applied to the left and right fluid pressure cylinders 2a and 2b.
The force of pushing the metal plate s is different.

If the pipe is formed only by controlling the pressure of the fluid pressure cylinders 2b, 2b, there is a risk that the pipe will not be formed properly if the metal plate s has meandering. However, the pipe forming line is equipped with guide rollers to prevent the metal sheet s from meandering, as well as breakdown rolls d and fin pass rolls e shown in Figs. 1 and 3, before and after the pressure-controlled pipe forming device. Therefore, the metal plate s does not meander to that extent. Therefore, even if pipe forming is performed only by pressure control while continuously feeding the metal plate s, it can be sufficiently put to practical use.

Furthermore, when the metal plate s is not being fed through the line, such as when the metal plate s is caught, a mechanical stopper may be provided to restrict the piston rod stroke of the fluid pressure cylinders 2a, 2b, for example. Therefore, the position of the side rolls 4a, 4b before biting is regulated, or the piston rod is retreated to the stroke end, and at the time of biting, pressure liquid is supplied to the fluid pressure cylinders 2a, 2b, and the forming operation is started. This allows sufficient molding to be carried out only by controlling the pressure.

In the embodiments of the present invention, the case where position control and pressure control are performed separately has been described, but it is also possible to implement them even if they are used together, and various other changes may be made without departing from the gist of the present invention. Of course, there are other things that can be added.

According to the pipe forming apparatus of the present invention, it is possible to sandwich the metal plate between the side rolls and the inner roll, and press both ends of the metal plate uniformly against the flange portion to roll the metal plate. Therefore, there will be no dents or sagging at both ends of the metal plate, and no buckling positions will occur.
Furthermore, it becomes possible to bend the end portions sufficiently.

Since it can be bent sufficiently in the side direction, it does not become a high oval.

Since the position of the side rolls is adjustable, damage to the width end is less likely to occur and meandering can be easily prevented.

Through the above steps, a pipe of good quality can be obtained.

Various excellent effects can be achieved.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram of the entire equipment for manufacturing ERW pipes,
Figure 2 is a view taken in the - direction of Figure 1, Figure 3 is a view taken in the - direction of Figure 1, and Figure 4 is a view taken in the - direction of Figure 1.
directional arrow view; FIG. 5 is a cross-sectional view of the electric resistance welded tube;
Figures 6A and 6B are explanatory diagrams showing the forming situation of the end of a metal plate when a conventional vertical type pipe forming device is installed in the equipment shown in Figure 1 to form a metal plate, and Figure 7 A and B are explanatory diagrams of the state of the butting surfaces when the forming of the metal plates formed as in Fig. 6 A and B is completely completed, and Fig. 8 is an explanatory diagram of the pipe forming apparatus of the present invention. be. In the figure, 2a and 2b are fluid pressure cylinders, 4a and 4b
are side rolls, 4a', 4b' are flanges, 6 is a position or load setting device, 7a, 7b are comparators, 8a, 8b are position detectors, 9a, 9b are pressure detectors, 16a, 16b are servo valves , 19a, 1
9b indicates an inner roll.

Claims (1)

[Claims] 1 A side roll that can move freely in the width direction of the metal plate by applying a load in the circumferential direction of the metal plate using an integrally fixed flange to cause the metal plate to buckle or constrict. an inner roll that is pressed against the drum-shaped surface of the roll;
A pipe forming apparatus comprising: a fluid pressure cylinder that supports side rolls during forming; and a control device that controls the position and/or pressure of the fluid pressure cylinder.