JP2963867B2 - Width changing device for continuous casting mold - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for changing the width of a continuous casting mold.

[0002]

2. Description of the Related Art Continuous casting molds for slab slabs are:
As shown in FIG. 5, a pair of long-side frames, that is, a movable long-side frame 2 provided so as to adjust the distance between the fixed long-side frame 1 and the fixed long-side frame 1, and the pair of long-side frames 1 2 and a pair of short side frames 3 and 4 sandwiched between them. Slab casting of various sizes is performed by changing the interval between the pair of long side frames 1 and 2 to change the thickness of the slab, changing the interval between the pair of short side frames 3 and 4 to change the width of the slab. Pieces can be cast.
In order to change the interval between the pair of short-side frames, each of the short-side frames 3, 4 is provided with a moving hydraulic cylinder 51, 52. The size of the hydraulic cylinders 51, 52 is the largest. When casting a thin slab, it must fit within the interval between the pair of long side frames 1 and 2. Therefore, the diameter of the moving hydraulic cylinders 51 and 52 cannot be increased,
Therefore, the cylinder stroke cannot be lengthened because it is restricted in terms of strength. For this reason, conventionally, two or more sets of molds having a certain width adjustment range were prepared, and the molds were replaced according to the required slab width. However, in order to replace the mold, the operation must be stopped, so that the productivity is inferior and the number of prepared molds increases.

In order to solve the above-mentioned increase in the number of preliminary molds, a width changing apparatus described in Japanese Utility Model Laid-Open No. 59-16754 has been proposed. In this conventional device, the mounting position of the hydraulic cylinder for moving the short side frame can be changed, and the hydraulic cylinder can be fixed by the lock pin at each of the first mounting position and the second mounting position. For this reason, when the cylinder stroke at the first mounting position and the cylinder stroke at the second mounting position are matched, the moving distance of the short side frame can be sufficiently increased,
Further, the reaction force during casting can be received by the lock pin. However, in this conventional apparatus, since the lock pin must be released and moved in order to change the mounting position of the moving hydraulic cylinder, the operation must be stopped once and the problem of poor productivity is still solved. could not. Also, even if the hydraulic cylinder itself is fixed with a lock pin, when the reaction force during casting is applied, the hydraulic oil moves slightly from the gap between the piston and the inner wall of the cylinder, or the piston rod moves due to oil leakage from the switching valve. Since the short-side frames 3 and 4 also move backward, this causes the solidified shell to break and cause a breakout.

[0004]

In view of such circumstances, the present invention increases the moving stroke of the short side frame to change the width of the mold without stopping the operation. An object of the present invention is to provide a mold width changing device that can cast a large product and has a large effect of preventing breakout.

[0005]

According to a first aspect of the present invention, there is provided a mold width changing apparatus, comprising: a pair of long side frames; and a pair of short side frames sandwiched between the pair of long side frames. , A mold width changing device for moving the short side frame along the long side frame, the width changing device includes a moving stepping cylinder in which a piston rod is connected to the short side frame; A slide guide fixed to one of the side frames and slidably supporting the cylinder body of the stepping cylinder for movement; and a piston rod connected to the cylinder body of the stepping cylinder for movement, and extending the piston rod. And a position adjusting hydraulic cylinder having a position holding function. The width changing device according to a second aspect of the present invention is characterized in that the position adjusting hydraulic cylinder is a stepping cylinder.
The width changing device according to the third aspect of the present invention is characterized in that the position adjusting hydraulic cylinder is a hydraulic cylinder with a position detector, and a function of holding an extended position of the piston rod by a position servo device is provided. And

[0006]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a side view of a width changing device according to an embodiment of the present invention, FIG. 2 is a plan view of the width changing device, and FIG. 3 is an operation explanatory diagram of the width changing device.

First, the configuration of the mold width changing apparatus of the present embodiment will be described with reference to FIGS. In the figure, reference numeral 3 denotes a short side frame similar to that of FIG. 5, and in the illustrated example, a base short side frame 3a, an exchange short side frame 3b, and a short side copper plate
It is made of 3C and exchanges with the base short side frame 3a.
3b is a detachable type that is detachably configured, but may be an integral type in which the base short side frame 3a and the exchange short side frame 3b are integrated.

The short side frame 3 has two tandem
A pair of width changing devices 10 are connected. 2 sets of width changing device
The reason for using 10 is to prevent the short sides 3 and 4 from being warped while moving, but when the vertical dimension is short, a set of width changing devices 10 may be used. Although the same width changing device 10 is provided for the other short side frame 4 as well, since they have exactly the same configuration, only the width changing device on the short side frame 3 side will be described.

Each width changing device 10 is configured as follows. Reference numeral 11 denotes a moving stepping cylinder, a cylinder body 12 is slidably supported by a slide guide 14, and a piston rod 13 is connected to the short side frame 3. The slide guide 14 is a fixed long side frame 1
Is fixed outside the portion where the copper plate 6 is provided. 21 is a stepping cylinder for position adjustment, which is a cylinder body.
22 is fixed to the fixed long side frame 1 by a fixing bracket 24, and the piston rod 23 is connected to the cylinder body 12 of the moving stepping cylinder 11 by a bracket 25.
Therefore, when the position adjusting stepping cylinder 21 is expanded and contracted, the cylinder body 12 of the moving stepping cylinder 11 is moved.
Can be changed along the width direction of the mold, and when the moving stepping cylinder 11 is expanded and contracted, the short side frame 3 can be displaced along the width direction of the mold.

The structure of the stepping cylinder constituting the moving stepping cylinder 11 and the position adjusting stepping cylinder 21 is as follows. In FIG.
(A) Figure is a control block diagram of the stepping cylinder, (B)
The figure is a sectional view of a main part of the stepping cylinder. As shown in FIG. 4 (A), the stepping cylinder converts a pulse train signal into a mechanical quantity by a pulse motor, drives a hydraulic control valve, and has a mechanical feedback mechanism for the position of the cylinder itself so that the rod position can be controlled. It is built-in.

The configuration will be described below with reference to FIG. A supply pressure PS is always applied to the rod-side oil chamber 31, and a control pressure is generated in the piston-side oil chamber 32 so as to balance the force and load generated in the rod-side oil chamber 31 by a mechanical feedback configuration. When no load is applied, the control pressure (PB) of the piston side oil chamber 32 is set so that PB = 1/2 PS. When a load is applied, the opening of the switching valve port (valve opening) is corrected, and PB It is changing. Now, when an extension command is applied to the electric pulse motor 33,
The feed screw 34 rotates and the switching valve 35 has a resolution (for example, 0.1 mm
) Just move. Then port 36 opens slightly,
The pressure (PS) of the rod-side oil chamber 31 flows from the port 36 to the port 37 to the piston-side oil chamber 32. As a result, the pressure in the piston-side oil chamber 32 increases from the balance point, and the piston rod 13 is pushed in the forward direction, balances again through the port of the switching valve, and stops. When contracting, open port 38,
The control pressure (PS) of the piston side oil chamber 32 is changed from port 37 to port
Escape to the return side through 38. As a result, the piston side oil chamber 32
The pressure decreases below the balance point, and the piston rod 13 is returned in the retreating direction, closes the port of the switching valve, balances again, and stops.

Based on the above-mentioned structural characteristics, the stepping cylinder has an advantage that the pressure in the oil chambers on both sides of the stepping cylinder is balanced with respect to the piston. is there. Therefore, even if a reaction force at the time of casting is applied during the operation, the short side frame 3 does not retreat even though it is only a little, so that an accident such as a breakout in which the solidified shell is torn and the molten steel leaks out beforehand. There is an advantage that the effect that can be prevented is large. Also, it has a resolution of ± 1 pulse regardless of stroke,
Usually, it has a positional accuracy of ± 0.1mm. Therefore, the mold width can be controlled with very high precision.

Next, the mold width changing operation in the present embodiment will be described with reference to FIG. (I) is a state in which both the moving stepping cylinder 11 and the position adjusting stepping cylinder 21 are fully extended, and the short side frame 3 is most advanced. In this case, the mold width is the narrowest. (II) is a state in which the position adjusting cylinder 21 is most contracted. As a result, the cylinder body 12 of the moving stepping cylinder 11 slides backward in the slide guide 14 and retreats by a distance a. Therefore, the short side frame 3 is also retracted by the distance a. (III) shows a state in which the piston rod 13 of the moving stepping cylinder 11 is contracted to the maximum, and as a result, the short side frame 3 is retracted by the distance b which is the stroke of the moving stepping cylinder 11.

As described above, according to the present invention, not only the stroke b of the moving stepping cylinder 11 but also the stroke a of the position adjusting stepping cylinder 21 is added to a wide range of the short side frame 3. The position can be adjusted. In the states (I) and (II), the moving stepping cylinder 11 is contracted, and in the state (III), the moving stepping cylinder 11 is contracted.
By extending 11, the short side frame 3 can be located at an arbitrary position within the entire adjustment area of the distance a + b. Moreover, there is an advantage that the positioning accuracy is extremely high.

Next, a third embodiment of the present invention will be described. In the above embodiment, a stepping cylinder is used as the position adjusting hydraulic cylinder 21, but a hydraulic cylinder with a position detector may be used instead. In this case, the piston rod extension position of the hydraulic cylinder with the position detector may be controlled by a position servo device so as not to retreat from the set position. That is, the detection signal from the position detector is always taken into the control unit, and when the piston rod contracts even a little due to the reaction force at the time of casting, the piston rod operates in the extension direction, and is always held at the same position. 4 can be prevented from retreating and breakout of molten steel can be effectively prevented.

[0016]

According to the first aspect of the present invention, the width of the mold is changed without stopping the operation by increasing the moving stroke of the short side frame, and the same mold is used to change the width of the slab from narrow to large. Can be cast. Claim 2
According to the invention, since the stepping cylinder which does not cause oil leakage between the oil chambers or oil from the switching valve is used, even if a reaction force at the time of casting is applied during operation, the short side frame is very small. Of course, since there is no retreat, there is an effect that accidents such as breakout such as breakage of the solidified shell and leakage of molten steel can be prevented. According to the third aspect of the present invention, the extended position of the piston rod of the position adjusting cylinder can be held at the set position by the position servo device based on the detection signal of the position detector, so that the short side frame does not retreat and the molten steel breaks. Out can be prevented.

[Brief description of the drawings]

FIG. 1 is a side view of a width changing device according to an embodiment of the present invention.

FIG. 2 is a plan view of the width changing device according to the embodiment of the present invention.

FIG. 3 is an explanatory diagram of an operation of the width changing device according to the embodiment of the present invention.

4A is a control block diagram of a stepping cylinder, and FIG. 4B is a cross-sectional view of a main part of the stepping cylinder.

FIG. 5 is a plan view of a mold for continuous casting.

[Description of Signs] 1 Long side frame 2 Long side frame 3 Short side frame 4 Short side frame 10 Width changing device 11 Stepping cylinder for movement 12 Cylinder body 13 Piston rod 14 Slide guide 21 Positioning stepping cylinder 22 Cylinder body 23 Piston Rod 24 fixing bracket

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁶ , DB name) B22D 11/04 316 B22D 11/16 106

Claims (3)

(57) [Claims] 1. A continuous casting mold having a pair of long side frames and a pair of short side frames sandwiched between the pair of long side frames, wherein the short side frame is moved along the long side frames. Equipped with a width changing device,
The width changing device is a slide guide fixed to one of a moving stepping cylinder in which a piston rod is connected to the short side frame and the long side frame, and slidably supporting a cylinder body of the moving stepping cylinder. And a hydraulic cylinder for position adjustment, wherein a piston rod is connected to a cylinder body of the stepping cylinder for movement, and has a function of holding an extended position of the piston rod. . 2. The width changing device according to claim 1, wherein the position adjusting hydraulic cylinder is a stepping cylinder. 3. The hydraulic cylinder for position adjustment according to claim 1, wherein the hydraulic cylinder for position adjustment is a hydraulic cylinder with a position detector, and has a function of holding an extended position of the piston rod by a position servo device. Width changing device.