Abstract: A cylinder liner or a cylinder block's bore portion formed of a composite alloy material reinforced with fibers and dispersed with ceramic particles. In the cylinder liner or the bore portion of the cylinder block, ceramic particles and alumina short fibers are uniformly dispersed in a light metal matrix. For producing the cylinder liner and the cylinder block, a preform having a shape identical with the cylinder liner or the bore portion is produced by mixing together the ceramic particles and the alumina short fibers. Molten light metal is infiltrated into voids of the preform during casting.

Abstract: A combination of a device for producing a closed deck type cylinder block and a sand core to be used in the device, the combination being capable of producing the block having high dimensional accuracy and eliminating precise dimensional control to the end face portion of the sand core. The sand core has a configuration identical with a water jacket formed in the engine block. Holding projections extending in an axial direction of a cylinder liner integrally protrude from a slide core of a movable die, and complementary holding bores are formed in the sand core, the bores being open at a top deck end face of the sand core. In one preferred embodiment, the top deck end face of the sand core is of a planner arrangement, and an end face of the slide core is formed with recesses for forming bridge portions therein. Casting is performed while maintaining a surface contact between the planner end face and the end face of the slide core. The contacting areas will become windows of the water jacket.

Abstract: A molten metal supply device capable of supplying molten metal with high precision to an injection sleeve of a die-casting machine, and capable of reducing molten metal leakage and damage to a molten metal conduit bridging between a holding furnace and the injection sleeve. The holding furnace is divided into a holding chamber and a supply chamber in fluid connection with the injection sleeve through the conduit. Both chambers can be selectively brought into and out of fluid connection by a stopper. First and second immersion bodies are immersibly provided to the chambers, respectively. The laser sensor detects a predetermined level of the molten metal. The first immersion body is immersed until the sensor detects the surface of the molten metal, whereupon the stopper blocks fluid communication between the chambers. By then lowering the second immersion body, molten metal is pushed out of the supply chamber and a predetermined amount of molten metal is supplied to the injection sleeve.

Abstract: A casting apparatus and method for producing a closed deck type cylinder block capable of facilitating removal of loose cores from the casted cylinder block. A die portion for forming a water jacket portion is formed with a plurality of notched portion having a bottom wall where a projection is provided. A pair of loose cores are fitted in each notched portion in such a manner that each parting face of the loose cores are in contact with each other. A first draft is provided at each loose cores and is mounted on the projection. In this case, the end of the parting face is placed on the projection. During casting, a molten metal is introduced into a space between the bottom wall and the first draft for forming a bridge portion. Upon solidification of the molten metal, the loose cores remain in the water jacket portion, and a bore is formed at the position corresponding to the projection.

Abstract: A LED radiates light on a plate held on plate cylinder upon receiving a radiation start signal, so as to form an irradiated area on plate. A photo diode (PD) senses substantially only conventional catoptric light reflected from irradiated area and generates the sensed signal representing the conventional catoptric light intensity. A data processing unit computes the dampening volume based on the sensed signal which is stored in storage device 9, storage device 9 then generates dampening volume signal. The LED is held in such manner that an incident angle of the light in connection with the surface of the irradiated area is made at predetermined angle sufficient for changing the conventional catoptric light intensity sensed by PD in accordance with the dampening volume.

Abstract: Prevention of damages on the printing surface of plastic gravure plate is the object. Radius of the plate cylinder 14, impression cylinder 11, and transfer drum 2 located between units are identical. The plate cylinders 14, 24 and the impression cylinders 11, 21 are arranged so that the lines L1 and L2 are parallel to each other. The grippers 12, 22 are arranged so that the gripper 22 of the impression cylinder 21 is at the point P.sub.21 when the gripper 12 of the impression cylinder 11 is at the point P.sub.11. Thus, a paper sheet transferred from the impression cylinder 11 to the transfer drum 2 at the nearest point P.sub.1 is transferred by the rotation of the transfer drum 2 at the nearest point P.sub.2 by the rotation of the transfer drum 2. Since the phases of the plate cylinders 14 and 24 are in agreement, the doctor blade is stopped at the same relative location for all the units.

Abstract: A method and apparatus capable of continuously discharging contaminated gas out of metal molds, the gas being generated prior to the casting step and including moisture. A gas vent valve is provided at a gas vent passage in communication with a mold cavity. A suction unit and a vacuum pump are selectively connected to the gas vent valve. After closure of the metal molds, the suction unit is connected to the gas vent valve to perform sucking interior of the mold cavity. By this suction, an external air is introduced into the metal molds through a pouring port of a shot sleeve. Thus, contaminated gas in the cavity is replaced with a clean air. During injection molding, the gas vent valve is connected to the vacuum pump for decompressing the mold cavity. Vapor explosion is avoidable since moisture content is removed from the mold cavity even if the molten metal is introduced into the cavity.

Abstract: A method for cooling a plunger tip of a die-casting machine for maintaining a proper clearance between a plunger tip and a shot sleeve. A proper hydraulic pressure in an injection cylinder is determined at which no galling occurs in the shot sleeve. Hydraulic pressure in the injection cylinder is measured several times in a state where no molten metal exists in the shot sleeve. For example, measured is the hydraulic pressure in the injection cylinder at the time of return stroke of the plunger tip immediately after injecting operation. Average hydraulic pressure is computed based on the plurality of measured hydraulic pressure. The average hydraulic pressure is compared with the proper hydraulic pressure. If the former is greater than the latter, clearance between the plunger tip and the shot sleeve is deemed to be too small. Thus, supply amount of cooling liquid to the plunger tip is increased to reduce a diameter of the plunger tip.

Abstract: A low pressure die-casting machine has a ladle unit, a molten metal pressurizing unit, a switching unit, and a controller. The ladle unit has an intake/discharge port with a cross-sectional area in a range of from 20 to 80 mm.sup.2 so as to be capable of successively supplying the molten metal to a desired location. The molten metal pressurizing unit is switchable between two positions. One position is for selectively supplying compressed air to the ladle to positively discharge the molten metal from the ladle through the intake/discharge port. The other position is for selectively isolating the ladle in order to retain the molten metal therein. The switching unit is connected between the molten metal pressurizing unit and the ladle. It is switchable between first and second change-over positions. The first change-over position is for providing fluid communication between the ladle and the molten metal pressurizing unit.

Abstract: A device for detecting galling which may produce deformations during an ejection process of die castings from a die. The device includes a setting device for storing a predetermined set value, the predetermined set value including an upper limit of acceleration of an ejector plate during the ejection process and a predetermined time period during the ejection process. An accelerometer is disposed to the ejector plate for measuring the acceleration thereof during the ejection process. A computing device is provided for comparing the acceleration measured by the accelerometer with the predetermined set value and outputting a warning signal when the acceleration measured at the accelerometer exceeds the upper limit during the time period. Thus, timely detection of galling can result.

Abstract: A gas venting system is connected to a downstream side of a gas vent valve through a gas exhaust line. An electromagnetic valve and a suction unit are connected to the gas exhaust line. A pressure switch is directly connected to the gas exhaust line to detect the pressure variation within the line. By the suction through the suction unit and the opening of the electromagnetic valve, the gas exhaust line is decompressed. If the line has a perforation, the pressure does not reach a predetermined pressure. If clogging occurs, the pressure reaches a predetermined pressure while the metal molds are open and the gas vent valve is open. Thus, accurate detection to the defects can be achieved regardless of the state of the metal molds and the internal volume of a vacuum tank.

Abstract: A laminar flow injection molding apparatus and a laminar flow injection molding method capable of directly judging flow mode of molten metal flowing into a metal mold, either laminar flow mode or turbulent flow mode. An injection molding apparatus includes metal molds in which a runner portion, a cavity, and a gas vent passage are formed in communication with a casting sleeve. Molten metal detection members are provided in confrontation with at least one of the runner portion, the cavity and the gas vent passage. In a single injecting operation, molten metal detection signal is generated each time the molten metal is brought into contact with the detection member. The molten metal detection member is connected to a counter circuit where numbers of the detection signals are stored as a count value. A judgment circuit to which a preset value is inputted is electrically connected to the counter circuit so as to compare the count value with the preset value.