Abstract: To form a through hole at one portion of a side wall, of an expanded portion made by plastically deforming one part of a metal tube radially outward, in a portion where the plate thickness gradually changes, a slide tool is withdrawn from inside a punch hole while applying hydraulic pressure to the inside of the side wall. At the instant of commencing withdrawal of the slide tool, the degree of progress in the shearing for the portions of the side wall matching with the two side edges of the punch hole is made different. Then, the timing for moving from shearing to rupture is made to coincide, so that of the side wall, the portions matching with the punch hole, are made reliably into a blank, and are extracted from the side wall.

Abstract: Using as a vehicle body reinforcing member a bent tube with mixed bends of inward and outward projection according to the present invention makes it possible, during a vehicle body collision, to absorb more energy than and exhibit better impact resistance than a vehicle body reinforcing member that uses one of a known straight tube and a curved tube of radius R entirely. Thus the dimensions (outside diameter, wall thickness) of the steel tube that is used as the vehicle body reinforcing member can be reduced, and the tube shape can be modified, while impact resistance is maintained. Modifying the shape in this manner makes it possible to provide the ever higher required level of vehicle body impact resistance at the same time that it reduces the weight of the vehicle body and lowers the cost. The present invention can therefore be widely used as an occupant protection technology.

Abstract: Using as a vehicle body reinforcing member a bent tube with mixed bends of inward and outward projection according to the present invention makes it possible, during a vehicle body collision, to absorb more energy than and exhibit better impact resistance than a vehicle body reinforcing member that uses one of a known straight tube and a curved tube of radius R entirely. Thus the dimensions (outside diameter, wall thickness) of the steel tube that is used as the vehicle body reinforcing member can be reduced, and the tube shape can be modified, while impact resistance is maintained. Modifying the shape in this manner makes it possible to provide the ever higher required level of vehicle body impact resistance at the same time that it reduces the weight of the vehicle body and lowers the cost. The present invention can therefore be widely used as an occupant protection technology.

Abstract: An impact absorber for a vehicle, which has a tubular shape and which is to be disposed between a side member and a bumper beam of the vehicle, so as to be crushed like an accordion in an axial direction thereof upon application of a compressive load thereto, for absorbing an impact energy. (a) The impact absorber has a tubular main body and a pair of attachment plates that are welded to be fixed to respective axially opposite end portions of the tubular main body. (b) The main body has a thin plate portion having a plate thickness smaller than 1.4 mm and constituting an axially intermediate portion of the main body, and a pair of thick plate portions having a plate thickness not smaller than 1.4 mm and provided integrally on axially opposite sides of the thin plate portion, the thick plate portions being arc-welded to be fixed to the respective attachment plates while being held in contact with the respective attachment plates.

Abstract: According to the hydroforming method by the invention, when slots with the aspect ratio of 3 or more are pierced onto the bulge-formed portion made by the hydroforming, even the piercing can be carried out within a series of processing steps in the hydroforming, thereby eliminating the piercing operation by means of the cumbersome machining process such as milling and ensuring an excellent slot configuration. Thus, the hydroformed parts by the invention are best suited for the automobile parts etc. where various piercing operations are required, and the mold used for the hydroforming method by the invention can be widely employed for processing the automobile parts etc., whereby the invention can be applied for processing the parts in automobiles and industrial machineries as well.

Abstract: A structure and method are provided for forming a through hole at one portion of a side wall of an expanded portion made by plastically deforming one part of a metal tube radially outward, in a portion where the plate thickness gradually changes. A slide tool is withdrawn from inside a punch hole while applying hydraulic pressure to the inside of the side wall. Regarding a tip end face of the slide tool, a portion facing the portion of the side wall where the plate thickness is relatively thick is recessed. At the instant of commencing withdrawal of the slide tool, the degree of progress in the shearing for the portions of the side wall matching with the two side edges of the punch hole is made different. Then, the timing for moving from shearing to rupture is made to coincide, so that of the side wall, the portions matching with the punch hole, are made reliably into a blank, and are extracted from the side wall.

Abstract: According to the hydroforming method by the invention, when slots with the aspect ratio of 3 or more are pierced onto the bulge-formed portion made by the hydroforming, even the piercing can be carried out within a series of processing steps in the hydroforming, thereby eliminating the piercing operation by means of the cumbersome machining process such as milling and ensuring an excellent slot configuration. Thus, the hydroformed parts by the invention are best suited for the automobile parts etc. where various piercing operations are required, and the mold used for the hydroforming method by the invention can be widely employed for processing the automobile parts etc., whereby the invention can be applied for processing the parts in automobiles and industrial machineries as well.

Abstract: Using as a vehicle body reinforcing member any one of a bent tube with a partial bend of radius R, a tube with a plurality of portions that are bent at radius R, and a bent tube with mixed bends of inward and outward projection according to the present invention makes it possible, during a vehicle body collision, to absorb more energy than and exhibit better impact resistance than a vehicle body reinforcing member that uses one of a known straight tube and a curved tube of radius R entirely. Thus the dimensions (outside diameter, wall thickness) of the metal tube that is used as the vehicle body reinforcing member can be reduced, and the tube shape can be modified, while impact resistance is maintained. Modifying the shape in this manner makes it possible to provide the ever higher required level of vehicle body impact resistance at the same time that it reduces the weight of the vehicle body and lowers the cost. The present invention can therefore be widely used as an occupant protection technology.

Abstract: A metal tube for reinforcing car body, and a car body reinforcement according to the invention have a curved portion extending over the entire longitudinal length or a local longitudinal length, wherein, when the reinforcement is assembled such that the outer periphery of the curved portion is aligned substantially in the direction of impact applied to the car body, the load ramp gradient, the maximum load and the absorbed energy are all enhanced in case of a car body collision. Particularly, an increase in the load ramp gradient as for the load property at the start of deformation provides an excellent crash capacity in reinforcing the car body. Moreover, the metal tube and the reinforcement according to the invention are capable of satisfying the current requirements for much more crash capacity of the car body, along with both a weight reduction of the car body and a reduced manufacturing cost, and therefore they are applicable in a wide field for protecting occupants in an automobile.

Abstract: An impact absorber for a vehicle, which has a tubular shape and which is to be disposed between a side member and a bumper beam of the vehicle, so as to be crushed like an accordion in an axial direction thereof upon application of a compressive load thereto, for absorbing an impact energy. (a) The impact absorber has a tubular main body and a pair of attachment plates that are welded to be fixed to respective axially opposite end portions of the tubular main body. (b) The main body has a thin plate portion having a plate thickness smaller than 1.4 mm and constituting an axially intermediate portion of the main body, and a pair of thick plate portions having a plate thickness not smaller than 1.4 mm and provided integrally on axially opposite sides of the thin plate portion, the thick plate portions being arc-welded to be fixed to the respective attachment plates while being held in contact with the respective attachment plates.

Abstract: A metal tube for reinforcing car body, and a car body reinforcement according to the invention have a curved portion extending over the entire longitudinal length or a local longitudinal length, wherein, when the reinforcement is assembled such that the outer periphery of the curved portion is aligned substantially in the direction of impact applied to the car body, the load ramp gradient, the maximum load and the absorbed energy are all enhanced in case of a car body collision. Particularly, an increase in the load ramp gradient as for the load property at the start of deformation provides an excellent crash capacity in reinforcing the car body. Moreover, the metal tube and the reinforcement according to the invention are capable of satisfying the current requirements for much more crash capacity of the car body, along with both a weight reduction of the car body and a reduced manufacturing cost, and therefore they are applicable in a wide field for protecting occupants in an automobile.

Abstract: According to the hydroforming method by the invention, when slots with the aspect ratio of 3 or more are pierced onto the bulge-formed portion made by the hydroforming, even the piercing can be carried out within a series of processing steps in the hydroforming, thereby eliminating the piercing operation by means of the cumbersome machining process such as milling and ensuring an excellent slot configuration. Thus, the hydroformed parts by the invention are best suited for the automobile parts etc. where various piercing operations are required, and the mold used for the hydroforming method by the invention can be widely employed for processing the automobile parts etc., whereby the invention can be applied for processing the parts in automobiles and industrial machineries as well.

Abstract: A bicycle crank arm is provided that is a light, highly strong, highly rigid and highly designed in a complex shape. The bicycle crank arm has a crank axle mounting end portion, a central crank body portion and a pedal mounting end portion. The hollow bicycle crank arm is preferably a one-piece, unitary member that is produced by a tube hydroforming method. The hollow bicycle crank arm has a crank axle attachment part located within the crank axle mounting end portion and a pedal spindle attachment part located within the pedal mounting end portion. The mounting end portions have a crank axle hole and a pedal spindle hole, respectively, with outside diameters that are smaller than the attachment parts, respectively.

Abstract: A sheet hydroforming method is disclosed wherein two stacked metallic sheets are clamped between a pair of upper and lower dies 10, 11 and a fluid is introduced and pressurized between mating surfaces of the metallic sheets, causing the metallic sheets to bulge into a space defined by die cavities 10b and 11b. A thru-hole 11d for introducing the fluid is formed in one of the dies so as to lead to a holding surface of the die, while a pierced hole for introducing the fluid is formed in one of the metallic sheets in a portion of the one metallic sheet which portion is in contact with a holding surface 10a (10b) of one of the dies, the pierced hole being positioned with the thru-hole 11d, then the fluid is introduced in a pressurized state between mating surfaces of the metallic sheets from the thru-hole through the pierced hole, thereby causing the metallic sheets to bulge. According to this method, a pressurized fluid can be introduced between the mating surfaces of blanks easily without leakage of the fluid.

Abstract: A liquid crystal display system which can accept input display data having a resolution which is larger (e.g. 1120×780 dots) or smaller (e.g. 640×480 dots) than a resolution of a liquid crystal panel (e.g. 1024×768 dots), and convert the input display data to reduced or enlarged display data for display on the liquid crystal panel. The system generates, for example, one new vertical or horizontal line based on two contiguous vertical or horizontal lines in the input display data. If the resolution of the input display data is larger than the resolution of the liquid crystal panel, the system replaces the two contiguous lines with the one new line. If the resolution of the input display data is smaller than the resolution of the liquid crystal panel, the system inserts the one new line between the two contiguous lines.

Abstract: A sheet hydroforming method is disclosed wherein two stacked metallic sheets are clamped between a pair of upper and lower dies 10, 11 and a fluid is introduced and pressurized between mating surfaces of the metallic sheets, causing the metallic sheets to bulge into a space defined by die cavities 10b and 11b. A thru-hole 11d for introducing the fluid is formed in one of the dies so as to lead to a holding surface of the die, while a pierced hole for introducing the fluid is formed in one of the metallic sheets in a portion of the one metallic sheet which portion is in contact with a holding surface 10a (10b) of one of the dies, the pierced hole being positioned with the thru-hole 11d, then the fluid is introduced in a pressurized state between mating surfaces of the metallic sheets from the thru-hole through the pierced hole, thereby causing the metallic sheets to bulge. According to this method, a pressurized fluid can be introduced between the mating surfaces of blanks easily without leakage of the fluid.

Abstract: A liquid crystal display system which can accept input display data having a resolution which is larger (e.g. 1120×780 dots) or smaller (e.g. 640×480 dots) than a resolution of a liquid crystal panel (e.g. 1024×768 dots), and convert the input display data to reduced or enlarged display data for display on the liquid crystal panel. The system generates, for example, one new vertical or horizontal line based on two contiguous vertical or horizontal lines in the input display data. If the resolution of the input display data is larger than the resolution of the liquid crystal panel, the system replaces the two contiguous lines with the one new line. If the resolution of the input display data is smaller than the resolution of the liquid crystal panel, the system inserts the one new line between the two contiguous lines.

Abstract: A liquid crystal display system which can accept display data having a resolution different from that of a screen for the liquid crystal display and display the display data. For example, a CPU outputs display data of 1120×780 dots and a liquid crystal panel has a 1024×768-dot resolution which is smaller than the display data resolution. The display screen of the liquid crystal panel comprises a linear arrangement of pixels. A data conversion section generates display data for a new horizontal or vertical line based on display data for two horizontal or vertical lines contiguous to each other and repeats replacement of display data of the two lines with the display data of the one line for reducing the number of horizontal lines of one screen and the number of dots of one line so as to match the resolution of the display data output by the CPU with the liquid crystal display.

Abstract: A liquid crystal display system which can accept display data having a resolution different from that of a screen for the liquid crystal display and display the display data. For example, a CPU outputs display data of 1120.times.780 dots and a liquid crystal panel has a 1024.times.768-dot resolution which is smaller than the display data resolution. The display screen of the liquid crystal panel comprises a linear arrangement of pixels. A data conversion section generates display data for a new horizontal or vertical line based on display data for two horizontal or vertical lines contiguous to each other and repeats replacement of display data of the two lines with the display data of the one line for reducing the number of horizontal lines of one screen and the number of dots of one line so as to match the resolution of the display data output by the CPU with the liquid crystal display.

Abstract: A data transfer control apparatus for a co-processor system. The co-processor system includes a memory; a memory bus connected to the memory; a main processor connected to the memory bus and having a control circuit for controlling data read/write relative to the memory, the main processor performing data transfer from/to the memory bus via a first data input/output terminal; and a co-processor connected to the memory bus via a second data input/output terminal. The control apparatus includes a high impedance setting circuit for selectively setting the first data input/output terminal at a high impedance state to electrically isolate the first data input/output terminal from the memory bus; and a control signal generator for selectively outputting a control signal to the high impedance setting circuit to cause the high impedance setting circuit to set the first data input/output terminal at the high impedance state.