Kawasaki Steel Corporation

Other

Sumitomo Heavy Industries, Ltd.

Stmicroelectronics Asia Pacific Pte Limited

Kotobuki Sangyo Co., Ltd.

Ryo Takeda

Hidenori Kondo

Shigeharu Ochi

Takao Ogawa

Tomoyasu Sakurai

Takeshi Tange

Yoshihiro Shinkai

Teruaki Tanaka

Sadao Yoshizawa

Atsumu Nakamura

Tadaaki Yanazawa

Takaya Suzuki

Akio Noda

Eisuke Yamanaka

Shou Inui

Masataka Inoue

Hiroshi Hagihara

Kiyoji Ino

Mitsuru Watanabe

Yukihiro Hoashi

A brightness limitation system is employed in a television circuit to prevent the black reference voltage level and the video signal from entering a minimum signal clipping zone, to provide precise correction signal, limiting the brightness, to maintain a constant black reference voltage level, and maintain a video signal with dynamic amplitude. The brightness limitation circuit detects a minimum signal level amongst the black reference signals from each color channel and compares the minimum signal with a fixed voltage level to generate a brightness feedback signal. The brightness feedback signal is then used to modify the black reference signal level for each color channel.

Automatic brightness limitation for avoiding video signal clipping

In a sizing rolling method carried out by installing at least 3 sets of 4-roll rolling mills in series, a central angle &thgr; of the perfect circle forming section of each rolling roll in a first path is set to less than 15&deg;. The central angle &thgr; is set to at least 45&deg; in a third path and the central angle &thgr; is set to at least 30&deg; in a second path B. The groove of each rolling roll is arranged such that each escape section is composed of the tangential line of an arc formed by the perfect circle forming section. A roller guide having four guide rollers is installed on the inlet side of the second path and the free surface of a workpiece is held and guided by the guide rollers. An angle &agr; of the V-shaped groove of each guide roller is set similar to the angle (90&deg;&plus;&thgr; ) between straight lines forming the escape section of the adjacent rolling rolls in the first path. With this technology, even if a wire has a diameter of 7.0 mm or less, an excellent surface property can be obtained while securing a large size free range.

Wire sizing rolling method

The present invention relates to a wire rod rolling line in which a finishing mill group rear stage is composed of a combination of a plurality of 4-roll mills. An object of the present invention is to provide a wire rod rolling line having a very high operating ratio capable of expanding a size free rolling range and at the same time capable of arranging pass schedules in which the pass schedule of an upstream pass is simplified in order to shorten a line stop time for adjusting mills. To achieve the object, the wire rod rolling line of the present invention is arranged such that three mills from the end of the finishing mill group are 4-roll mills, these three mills are installed in series with the reducing directions thereof dislocated by 45&deg;, the two mills from the end are driven by a common motor and the third 4-roll mill from the end is separately driven.

Wire rod rolling line

The present invention relates to a roll stand for bar and wire rod rolling mill, capable of being applied to various sizes of bars and wire rods by a small number of housing block sets, permitting maintenance work therefor to be carried out easily, and having characteristics in the housing thereof. The roll stand for bar and wire rod rolling mill according to the present invention is characterized in that the housing is divided into two, i.e. a roll block and a driving block by a plane including a position in which a driving gear and a driven gear are meshed with each other or a position in the vicinity of this position, whereby the number of housing block sets to be prepared is reduced. This enables the housing manufacturing cost to be lowered, and the replacement of a roll to be carried out efficiently.

Roll stand for bar and wire rod rolling mill

A rolling mill having a plurality of roll units, a rolling-reduction adjusting device of an eccentric-cartridge type, and a roll-alignment adjusting device, all mounted on its housing. The housing is split into freely separable and joinable first and second housing segments. The housing segments have semicircular bearing-holder segments formed in their joint surfaces. The shafts of the roll units are held between the first and second housing segments by being journaled in eccentric cartridges which are fitted in the bearing holders consisting of the semicircular bearing-holder segments. The roll-alignment adjusting device includes adjusting mechanisms and chucks to connect the shaft ends of the roll units to the adjusting rods of the adjusting mechanisms. Each adjusting mechanism further comprises (i) an outer nut which is fixed to the housing and has internal threads, (ii) a middle nut which has internal and external threads, the external threads engaging the internal threads of the outer nut, and is rotated externally, and (iii) an adjusting rod which has external threads to engage the internal threads of the middle nut. A first thread joint is defined by the internal threads of the outer nut. An external thread is defined by the middle nut and the second thread joint by the internal threads of the middle nut and the external threads of the adjusting rod. The first and second thread joints are each given a thread of the opposite hand and a different pitch.

Rolling mill

In a plural-roll rolling mill having a pass line arranged by the respective sets of rolls, each having a caliber formed on the outside peripheral surface thereof, the outside peripheral surfaces being disposed close to each other, the calibers of the rolls being cut with a cutting tool of a three-dimensionally (forward and rearward, rightward and leftward and upward and downward) movable cutting machine. The rolling mill, which has a reference column disposed on the outside surface thereof at a position spaced apart from the pass line by a predetermined distance, is removed from a rolling line and fixed, and the positional alignment of the cutting tool is carried out by causing a contact sensor disposed on the cutting machine at a position spaced apart from the cutting tool by a predetermined distance to come into contact with the reference column. With this arrangement, there are provided a method and apparatus capable of cutting the rolls of the plural-roll rolling mill while mounted on the rolling mill.

Roller cutting method for a plural-roll rolling mill

The present invention provides a rolling method and apparatus for manufacturing concrete-reinforcing steel bars, wherein the invention provides for obtaining various concrete-reinforcing steel bars satisfying the required specifications for knot height while using the same finishing rolls even if the diameters of the final product steel bars are different. According to the present invention, two pairs of rolls (total of four rolls) each having a roll caliber and one or more knotting round calibers are used for the final finishing pass, and the two pairs of rolls are arranged to exert rolling pressures in two orthogonal directions on a raw material S.

Rolling method and rolling facility for manufacturing steel bars for

An apparatus for guiding various sized round steel bars to calibers of rolls while stably holding the round steel bar. The round steel bar can be securely prevented from being twisted with a small amount of a holding force, so that a product with a desirable and accurate dimension can be manufactured. The guide apparatus comprises guide rollers installed at the inlet of at least one of a plurality of multi-roll sizing mills, each stand of which is composed of at least three rolls disposed in a line. The method of guiding the round steel bars comprises a step of elastically holding the free or unrolled surface portion of the round steel bar with a press force in the range of approximately 100 to 500 kg. With the round steel bar guide method and apparatus, a round steel bar is pressed and elastically held on the free surface of the guide apparatus.

Round steel bar guide apparatus and method

Roller cutting method and apparatus for a plural-roll rolling mill

A four-roller type sizing mill apparatus for forming round steel rods, comprises two four-roller mills each having two pair of facing rollers. One pair of facing rollers is arranged in rolling direction perpendicular to the rolling direction of the other pair of rollers. The two four-roller mills are arranged in line, with the rolling direction of one of the two four-roller mills being shifted by 45.degree. from the rolling direction of the other four-roller mill. The two pair of rollers of a first four-roller mill positioned closer to the rolling material inlet are separated from each other by a distance which is greater than zero and not greater than five times the projected contact length of one of the pair of rollers positioned closer to the rolling material inlet. The distance is measured between a first standard straight line which passes through the centers of one of the pair of rollers and lies on a plane parallel to the side surfaces of the same pair of rollers and a second standard straight line obtained by projecting the axes of the other pair of rollers onto the above-mentioned plane.

Four-roller type sizing mill apparatus for producing round steel rods

A method of rolling steel rods or wires by grooveless rolls for reducing sectional areas of the rods or wires and achieving a stable rolling operation with high efficiency by limiting to less than a predetermined value the ratio of a long side to a short side of a cross-section of a blank material (having a rectangular cross-section) which has passed through each pair of grooveless rolls or limiting the ratio of the diameter of each pair of grooveless rolls to the gap therebetween. The method of rolling steel rods or wires by grooveless rolls also achieves high elongation efficiency to make stable the rolling operation by limiting the ratio of the diameter of each pair of grooveless rolls to the gap therebetween. The method uses a grooveless roll entry guide in the grooveless rolling so as to securely hold a blank material from entry to exit in a gap between the pair of grooveless rolls to eliminate overturns at the ends of the blank material and fins extending from the material due to the overturns.

Growing community of inventors

Kurashiki, Japan

Ryo Takeda