JP4500176B2 - Variable width device for continuous casting mold - Google Patents

Description

  The present invention relates to a variable width device for changing the casting width of a continuous casting mold composed of a short side frame and a long side frame of a mold.

  In a continuous casting mold formed by sandwiching a pair of opposing short-side frames between opposing long-side frames, continuous casting in which the short-side frame is movable in the width direction in order to be able to handle slabs of various widths. The casting mold is known, and various adjustment methods for moving the short side frame have been proposed. Conventional methods include a method using a fluid pressure such as a cylinder and a hydraulic pump, and a mechanical method. In the method using fluid pressure, special high-precision actuators such as electro-oil stepping cylinders are used, which causes the equipment cost to be high, and causes breakout when runaway by using unstable hydraulic servo There are drawbacks.

  The mechanical method is disclosed in Patent Documents 1 to 3, for example.

  Patent Document 1 discloses a width adjusting device that has a screw spindle above and below a short side frame, and rotates the input shaft to operate the screw spindle via a differential gear mechanism and a bevel gear.

  Further, Patent Document 2 has two advancing and retracting shafts for moving the short side frame forward and backward, and is linked to an input shaft provided with a clutch via the worm gear device. A variable width mold for continuous casting is disclosed which is linked to a drive shaft linked to a drive source via a gear motor and a shaft coupling.

  Further, in the cited document 3, there are screw spindles on the upper and lower sides of the short side frame, gear mechanisms are connected to the respective screw spindles, and the drive shaft extending from the gear mechanism is driven by an electromagnetic clutch and a transmission device. There is disclosed a mold short side moving device connected to the.

Further, as a method of moving the short side frame, as shown in FIGS. 1 to 3 to be described later, the motor 8 is driven and the speed reducer 7, the universal joint 6, the relay box 5, the universal joint 4, and the input of the worm jack 3. The input shaft 10 is moved through the shaft 3a to move the short side frame 1 to form a taper as shown in FIG.
Japanese Utility Model Publication No. 54-32992 Japanese Utility Model Publication No.59-1451 JP 62-192245 A

  As shown in FIG. 4, by setting the short side frame to an appropriate taper T1, the slab can be accurately cast without causing casting defects such as breakout and slab cracking. When the taper becomes a taper T2 deviating from the proper taper T1 due to rush or the like, and the taper error T increases, a casting defect occurs.

  In the conventional mechanical continuous casting mold variable width device, when changing the width direction of the short side frame, the connecting portion between the universal joint and the worm jack or the connecting portion between the universal joint and the speed reducer, the output shaft, A taper error occurs in the short side frame due to the backlash of the pin connection part and the reducer, worm jack, or universal joint, so that there is a problem that it cannot be set with high accuracy and is troublesome to correct.

  Therefore, the present invention provides a continuous casting mold composed of a short side frame and a long side frame of a mold, a backlash of a connecting portion with a universal joint, a worm jack, a speed reducer, and a short side frame by their backlash. It is an object of the present invention to provide a variable width device capable of preventing the occurrence of casting defects that can be accurately set to an appropriate taper while suppressing a taper error.

The continuous casting mold width varying apparatus of the present invention connects two shafts to the upper and lower surfaces of a short side frame of a continuous casting mold formed by sandwiching a pair of opposing short side frames between opposing long side frames. In the variable width device that changes the casting width of the continuous casting mold by moving the short side frame forward or backward with the shaft, the pin is fitted to the bracket and the output shaft of the worm jack standing on the back of the short side frame The pinion shaft side of the worm jack is pivotally connected to the universal joint, the other end of the universal joint is also pivotally connected to the drive device, and the worm gear reduction ratio 1 / I was a 1 / I ≦ 1/30, the backlash Bp short side frame and the worm jacks output shaft and Bp ≧ 0.1 mm, below Br, Bu, 1 / I, Bj, L, B , Characterized in that a and h is a taper error T of the short side frame satisfies the following equation is set to be T ≦ lmm.

T = {(Bru + ΣBuu) / 3 60 × (1 / Iu) × Lu + Bju + Bpu + (Brs + ΣBus) / 3 60 × (1 / Is) × Ls + Bjs + Bps} / a × h
here,
Br: Reducer backlash (°)
Bu: Universal joint backlash (°)
1 / I: Worm jack worm gear reduction ratio Bj: Worm jack backlash (mm)
L: Screw lead (mm)
Bp: looseness of pin part (mm)
a: Upper and lower worm jack spacing (mm)
h: Short side frame length (mm)
(Note that the subscript u in the formula is related to the upper worm jack. The subscript s is related to the lower worm jack)

  According to the present invention, the slab can be accurately pulled out without causing a casting defect such as breakout or slab cracking by setting the taper error T to satisfy T ≦ lmm while satisfying the above formula.

  FIG. 1 is a view showing an example of a continuous casting mold width varying device according to the present invention, FIG. 2 is a view taken along the line A-A in FIG. 1, FIG. 3 is a view taken along the line BB in FIG. It is explanatory drawing of the movement state of a short side.

  In FIG. 1 to FIG. 3, a long-side frame 1 is disposed opposite to each other, and a pair of opposed short-side frames 2 are sandwiched between the long-side frames 1 to form a mold. The long side frame 1 includes an electromagnetic stirring coil on the back side of the copper plate 1a.

  Brackets 9 are fixed to the upper and lower sides of each opposing short side frame 2, and each bracket 9 is connected to the output shaft 10 of the worm jack 3 via a pin 11 so as to be rotatable. By the operation of the output shaft 10, the short side frame 2 can be rotated around the pin 11 and inclined to form a taper. The worm jack 3 is preferably a ball screw jack provided with a ball screw, and the backlash can be reduced as much as possible when the screw advances.

  The input shaft 3 a of the worm jack 3 is connected to the speed reducer 7 through the universal joint 4, the relay box 5, and the universal joint 6 that are sequentially connected, and the speed reducer 7 is connected to the motor 8. The relay box 5 is installed according to the location of the attachment / detachment, the motor, and the speed reducer when the mold is replaced.

  When moving the short side frame 1, the motor 8 is driven to move the input shaft 10 forward or backward through the input shaft 3 a of the speed reducer 7, the universal joint 6, the relay box 5, the universal joint 4, and the worm jack 3. The short side frame 1 is moved. The upper and lower output shafts 10 are alternately operated to move the short side frame 1 and, as shown in FIG. 4, the taper error T is set to satisfy T ≦ lmm.

  FIG. 5 is an explanatory diagram of conditional expressions applied to the variable width apparatus of the present invention. In FIG. 5, the bracket and the output shaft of the worm jack that are erected vertically on the back of the short side frame are connected with pins, and the pinion shaft side of the worm jack is connected to one end of the universal joint and connected. The other end side of the motor is connected to the drive device via a speed reducer. The worm gear reduction ratio 1 / I ≦ 1/30, the backlash Bp ≧ 0.1 mm of the connecting portion of each joint, and as shown in FIG. 4, the taper error T expressed by the following equation is T ≦ lmm. Set to.

  The taper error T includes the backlash of the reducer, universal joint and worm jack, reduction ratio of worm jack, screw lead of worm jack, backlash of pin part, vertical worm jack interval, and short side frame length. As a factor, the taper error should satisfy the following formula.

T = {(Bru + ΣBuu) / 3 60 × (1 / Iu) × Lu + Bju + Bpu + (Brs + ΣBus) / 3 60 × (1 / Is) × Ls + Bjs + Bps} / a × h
here,
Br: Reducer backlash (°)
Bu: Universal joint backlash (°)
1 / I: Worm jack worm gear reduction ratio Bj: Worm jack backlash (mm)
L: Screw lead (mm)
Bp: looseness of pin part (mm)
a: Upper and lower worm jack spacing (mm)
h: Short side frame length (mm)
(Note that the subscript u in the formula is related to the upper worm jack. The subscript s is related to the lower worm jack)
When the taper error T exceeds 1 mm, casting defects such as breakout and slab cracking frequently occur. Therefore, T ≦ lmm is set so that casting defects such as breakout and slab cracking do not occur.

Further, the taper error can be reduced by setting the worm gear reduction ratio 1 / I ≦ 1/30 . By setting the short side frame and the worm jack output shaft backlash Bp ≧ 0.1 mm, the short side frame can be easily tapered.

Table 1 shows the calculation results.

  As shown in Table 1, according to the present invention, the taper error T could be kept within T ≦ lmm, and a sound slab could be cast.

The figure which shows an example of the width variable apparatus of the casting_mold | template for continuous casting by this invention. The AA arrow directional view of FIG. The BB arrow line view of FIG. Explanatory drawing of the movement state of a mold short side. Explanatory drawing of the conditional expression applied to the variable width apparatus of this invention.

Explanation of symbols

1: Long side frame 1a: Copper plate 2: Short side frame 3: Worm jack 3a: Input shaft 4: Universal joint 5: Relay box 6: Universal joint 7: Reduction gear 8: Motor 9: Bracket 10: Output shaft 11: Pin

Claims (2)

Two shafts are connected to the upper and lower surfaces of the short-side frame of the continuous casting mold formed so as to sandwich the pair of opposing short-side frames between the opposing long-side frames, and the short-side frame is moved forward or backward by the shafts. In a variable width device that varies the casting width of the continuous casting mold,
The bracket and the output shaft of the worm jack that are erected on the back of the short side frame are connected by fitting a pin, the pinion shaft side of the worm jack is connected to the universal joint, and the other end of the universal joint is connected. The worm gear reduction ratio 1 / I is 1 / I ≤ 1/30, the back frame Bp between the short side frame and the worm jack output shaft is Bp ≥ 0.1 mm. below Br, Bu, 1 / I, Bj, L, Bp, molds for continuous casting of a and h is characterized in that satisfies the following equation taper error T short side frame is set to be T ≦ lmm Variable width device.
T = {(Bru + ΣBuu) / 3 60 × (1 / Iu) × Lu + Bju + Bpu + (Brs + ΣBus) / 3 60 × (1 / Is) × Ls + Bjs + Bps} / a × h
here,
Br: Reducer backlash (°)
Bu: Universal joint backlash (°)
1 / I: Worm jack worm gear reduction ratio Bj: Worm jack backlash (mm)
L: Screw lead (mm)
Bp: looseness of pin part (mm)
a: Upper and lower worm jack spacing (mm)
h: Short side frame length (mm)
(Note that the subscript u in the formula is related to the upper worm jack. The subscript s is related to the lower worm jack)   2. The continuous casting mold width varying apparatus according to claim 1, wherein the worm jack is a ball screw jack provided with a ball screw.

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