Twin-drum type continuous casting apparatus

Abstract: The present invention intends to provide a twin-drum type continuous casting apparatus, in which even when a side weir is vibrated at a high speed, vibration of the side weir in the axial direction of the cooling drums is suppressed, generation of run-out in a cast piece is prevented, and thereby elongation of lifes of the side weirs and refractory materials is made possible. The subject matter is a twin-drum type continuous casting apparatus including a pair of side weirs (52) vibrating along end surfaces of cooling drums (51), characterized in that a support shaft (6) serving as a center of rotation of the vibration of the side weir (52) is disposed lower than a molten metal surface and higher than a minimum gap position of the cooling drums (51), and a vibration exciting shaft (2) for applying vibration to the side weir (52) is disposed lower than the above-mentioned minimum gap position.

Description: BACKGROUND OF THE INVENTION: 1. Field of the Invention: The present invention relates to a twin-drum type continuous casting apparatus provided with vibration-exciting means in a side weir. 2. Description of the Prior Art: A twin-drum type continuous casting apparatus is such apparatus that a basin is formed by a pair of rotary cooling drums and a pair of side weirs pressed to the both end surfaces of these drums, and while molten metal is being fed to this basin, a belt-like cast piece is ejected downwards from the gap between the both cooling drums. And it has been heretofore practiced to cause the side weir to vibrate along the end surface of the cooling drum for the purpose of prevent a solidified shell from fixedly securing to the side weir. In the following, description will be made on a side weir vibrating device in a twin-drum type continuous casting apparatus in the prior art with reference Figs. 3 and 4. Fig. 3 is a side view of the side weir vibrating device, in which an essential portion is partly cut away, and Fig. 4 is a cross-section view taken along line IV-IV in Fig. 3 as viewed in the direction of arrows. In this casting apparatus, side weirs 52 are pressed against a pair of cooling drums 51 by means of pressing devices 42 via vibrating plates 31, and thereby a basin is formed in the space delimited by the pair of drums 51 and the side weirs 52 on the opposite sides thereof. The cooling drums 51 rotate while being held in slide contact with refractory materials 53 on the surfaces of the side weirs 52. On the rear surface of the vibrating plate 31 fixed to each side weir 52 are provided a bearing 37 and a guide 34. Within the guide 34 is fitted a slider 33 so as to be slidable in the vertical direction along the guide. A support shaft 36 fixedly provided on the frame 41 is rotatably inserted in the bearing 37, and an eccentric tip end portion of a vibration exciting shaft 32 rotatably supported from the frame 41 is pivotably mounted to the slider 33. In this way, when the vibration exciting shaft 32 is rotated by means of a driving unit (not shown), the slider 33 vibrates the vibrating plate 31 about the support shaft 36 while sliding within the guide 34. In a continuous casting operation, the pair of cooling drums 51 are rotated in the direction of arrows, the side weirs 52 are pressed against the opposite end surfaces of the cooling drums 51 by means of the pressing devices 42, and while the side weirs 52 are vibrated about the support shafts 36 in the direction of arrows shown at the location of the guide 34 in Fig. 4, molten metal is fed from a gate (not shown) disposed at the above into the above-described basin. Then, molten metal 61 in the basin is cooled by the cooling drums 51, and thereby a solidified shell is formed on the surface, while a belt-like cast piece 62 is ejected to the below. At that time, by vibrating the side weirs 52, the solidified shell is prevented from fixedly securing to the refractory materials 53 on the surfaces of the side weirs 52. In the above-described side weir vibrating device in the prior art, due to the fact that the support shaft 36 is disposed lower than the position of the minimum gap space between the both rotary cooling drums 51 (hereinafter called "kissing point") and the vibrating shaft 32 is disposed in the middle between a molten metal surface 60 and the kissing point, the side weir 52 is reciprocated in the lateral direction by the vibrating shaft 32 disposed in the vicinity of its center of gravity, and is rotated about the support shaft 36 under the kissing point. Since the vibration exciting force generated by the vibrating shaft 32 for the side weir 52 is applied to the vicinity of the center of gravity of the side weir 52, because of a large moment of inertia due to rotation of the side weir 52 about the support shaft 36 upon high-speed vibration the side weir 52 would vibrate also in the axial direction of the cooling drums 51, hence there was a shortcoming that a gap clearance would be produced momentarily between the refractory material 53 of the side weir 52 and the end surfaces of the cooling drums 51, at the next moment the refractory material 53 would collide against the end surfaces of the cooling drums 51, and thereby run-out would be generated in a cast piece or a life of the refractory material would be shortened. SUMMARY OF THE INVENTION: It is therefore one object of the present invention to provide a twin-drum type continuous casting apparatus, in which the above-mentioned shortcoming of the apparatus in the prior art can be eliminated, vibration of side weirs in the axial direction of cooling drums can be suppressed even when the side weirs are vibrated at a high speed, generation of run-out in a cast piece is prevented, and elongation of lifes of side weirs and refractory materials is made possible. According to one feature of the present invention, there is provided a twin-drum type continuous casting apparatus, in which a basin is formed by a pair of cooling drums juxtapositioned and rotating in the opposite directions to each other and a pair of side weirs vibrating along the end surfaces of the aforementioned drums, and while molten metal is being fed to the above-mentioned basin a belt-like cast piece is ejected downwards from a gap between the aforementioned drums; improved in that a support shaft serving as a center of rotation of the above-mentioned vibration is disposed lower than a molten metal surface and higher than a minimum gap position (kissing point) of the above-mentioned drums, and vibration exciting means for applying the aforementioned vibration is disposed lower than the above-mentioned minimum gap position (kissing point). As described above, in the twin-drum type continuous casting apparatus according to the present invention, owing to the fact that side weirs are vibrated with a small amplitude by means of vibration exciting shafts disposed lower than a kissing point of cooling drums about support shafts disposed lower than a molten metal surface and higher than the kissing point preferably in the vicinity of centers of gravity of the side weirs or centers of gravity of the surfaces held in contact with molten metal of the side weirs, a moment of inertia of the side weir rotating about the support shaft can be made small, and vibration of the side weirs in the axial direction of the cooling drums can be prevented. As a result, a gap would not be produced between a side weir and cooling drums, run-out in a cast piece can be prevented, and lifes of side weirs and refractory materials provided on their surfaces can be elongated. The above-mentioned and other objects, features and advantages of the present invention will become more apparent by reference to the following description of one preferred embodiment of the invention taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS: In the accompanying drawings: Fig. 1 is a side view partly cut away of a side weir vibrating device in a twin-drum type continuous casting apparatus according to one preferred embodiment of the present invention; Fig. 2 is a cross-section view taken along line II-II in Fig. 1 as viewed in the direction of arrows; Fig. 3 is a side view partly cut away of a side weir vibrating device in a twin-drum type continuous casting apparatus in the prior art; and Fig. 4 is a cross-section view taken along line IV-IV in Fig. 3 as viewed in the direction of arrows. DESCRIPTION OF THE PREFERRED EMBODIMENT: In the following, a twin-drum type continuous casting apparatus according to the present invention will be described in detail with respect to one preferred embodiment. In the illustrated apparatus, a basin is formed by urging respective side weirs 52 against a pair of cooling drums 51 via respective vibrating plates 1 by means of pressing devices 42. The cooling drums 51 rotate while being kept in slide contact with refractory materials 53 on the surfaces of the respective side weirs 52. On the rear surfaces of the vibrating plates 1 fixed to the side weirs 52 are provided bearings 7 at positions lower than a molten metal surface and higher than a kissing point of the cooling drums 51, preferably in the vicinity of centers of gravity of the side weirs or centers of gravity of the surfaces held in contact with molten metal of the side weirs, also guides 4 are provided lower than the kissing point of the cooling drums, sliders 3 are slidably fitted in the respective guides 4, tip end portions of support shafts 6 fixedly provided on a frame 11 are rotatably inserted in respective bearings 7 fixedly secured to the respective vibrating plates 1, and eccentric tip end portions of vibration exciting shafts 2 rotatably supported from the frame 11 are pivotably mounted to the respective sliders 3. With such arrangement, if the vibration exciting shaft 2 is rotated by a drive unit (not shown), the slider 3 reciprocates as sliding in the corresponding guide 4 and causes the vibrating plate 1 to vibrate with a small amplitude along a circular arc passing the axis of the vibration exciting shaft 2 about the axis of the support shaft 6, and thereby the side weir 52 fixed to the vibrating plate 1 is vibrated. Since the side weir 52 can reduce its moment of inertia in the vibration as a result of the fact that it is rotated about a point close to its center of gravity, vibration of the side weir 52 in the axial direction of the cooling drums can be prevented. In this connection, a frequency of the vibration applied to the side weir 52 is 15 - 20 Hertz. In a continuous casting operation, the pair of cooling drums 51 are rotated in the direction of arrows in Fig. 2, the side weirs 52 are urged against the opposite end surfaces of the cooling drums 51 by means of pressing devices 42, and while the side weirs 52 are vibrated about the axes of the respective support shafts 6 in the direction of arrows indicated at the position of the guide 4 in Fig. 2, molten metal is fed from a gate (not shown) provided at the above to a basin formed in the space delimited by the both cooling drums 51 and the side weirs 52 on the both sides of the cooling drums 51, molten metal 61 in the basin is cooled by the cooling drums 51, a solidified shell is thereby formed on the surface, and a belt-like cast piece 62 is ejected to the below. At that time, the side weirs 52 vibrate along the end surfaces of the cooling drums 51 to prevent a solidified shell from adhering to refractory materials 53 on the surfaces of the side weirs 52, but since vibrations in the axial direction of the cooling drums can be prevented, it would never occur that a gap clearance is produced between the refractory material 53 on the surface of the side weir 52 and the end surfaces of the cooling drums 51 and run-out in a cast piece is produced, and as the collision between the refractory materials 53 and the cooling drums 51 is also suppressed, it has become possible to elongate the life of the side weirs 52 and the refractory materials 53. Furthermore, according to the present invention, by employing the above-mentioned construction and disposing a support shaft of a vibrating plate higher than a kissing point of the cooling drums, a moment of inertia of the side weir with respect to rotation can be made small, as a result, vibrations of the side weir in the axial direction of the cooling drums can be prevented, and thereby it has been made possible to prevent run-out in a cast piece and elongation of lifes of side weirs and refractory materials held in slide contact with the end surfaces of cooling drums. While an apparatus according to the present invention has been described above on the basis of one preferred embodiment illustrated in the drawings, it is a matter of course that the present invention should not be limited to the illustrated embodiment but many changes and modifications could be made thereto without departing from the invention.

Claims: A twin-drum type continuous casting apparatus, in which a basin is formed by a pair of cooling drums juxtapositioned and rotating in the opposite directions to each other and a pair of side weirs vibrating along the end surfaces of said drums, and while molten metal is being fed to said basin a belt-like cast piece is ejected downwards from a gap between said drums; characterized in that a support shaft (6) serving as a center of rotation of said vibration is disposed lower than a molten metal surface (60) and higher than a minimum gap position of said drums (51), and vibration exciting means (2) for applying said vibration is disposed lower than said minimum gap position. A twin-drum type continuous casting apparatus as claimed in Claim 1, characterized in that said vibration exciting means (2) is an eccentric rotary shaft, and said eccentric rotary shaft (2) is rotatably coupled to a slider (3) held slidably in the vertical direction by a guide (4) mounted to the side of said side weir. A twin-drum type continuous casting apparatus as claimed in Claim 1 or 2, characterized in that a vibrating plate (1) is fixed to the outside of said side weir (52), and said support shaft (6) and vibration exciting means (2) are coupled to said vibrating plate (1). A twin-drum type continuous casting apparatus as claimed in Claim 1, 2 or 3, characterized in that said support shaft (6) is disposed in the vicinity of a center of gravity of said side weir (52). A twin-drum type continuous casting apparatus as claimed in Claim 1, 2, 3 or 4, characterized in that said support shaft (6) is coupled to the side of said side weir (52) via a bearing for rotatably supporting it.

Inventors: ARAI TAKASHI, OKA HIDEKI, SASAKI KUNIMASA, WAKIYAMA YOUICHI, ARAI, TAKASHI, OKA, HIDEKI, SASAKI, KUNIMASA, WAKIYAMA, YOUICHI, Arai, Takashi, c/o Hikari Works, Oka, Hideki, c/o Hikari Works, Sasaki, Kunimasa, c/o Hiroshima Machinery Works, Wakiyama, Youichi, c/o Hiroshima Machinery Works
Applicants: MITSUBISHI HEAVY IND LTD, NIPPON STEEL CORP, MITSUBISHI JUKOGYO KABUSHIKI KAISHA, NIPPON STEEL CORPORATION
Application year: 1993
Main classification: B22D11
IPC codes: B22D11