Ryobi Limited

Noriyoshi Yamauchi

Hitoshi Ishida

Kazuaki Kawai

Tomoyoshi Miwa

Hirotake Usui

Yasuyuki Mizukusa

Yoshiaki Egoshi

Akio Kobashi

Nobuo Iwakuni

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.

Method for discharging gas out of metal molds and apparatus therefor

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. The second change-over position is for providing fluid communication between the ladle and the atmosphere. The controller is connected to the molten metal pressurizing unit for selectively driving the molten metal pressurizing unit. The controller is also connected to the switching unit for driving the switching unit.

Low pressure die-casting machine and low pressure die-casting method

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.

Apparatus for detecting defects at gas exhaust line in casting machine

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. Since flow mode of the molten metal can be directly detected, quality of the casted product can be determined even during the casting process, to thereby enhance productivity.

Laminar flow injection molding apparatus and laminar flow injection

An automatic molten metal supplying device capable of supplying the molten metal within a short period of time while maintaining accuracy in a supply amount and preventing dripping of the molten metal from a ladle and temperature decrease of the molten metal during its transferring state even if the transferred molten metal is of a small volume. A molten metal intake/discharge port is formed at a bottom portion of a ladle, and an atmosphere communication/blockage unit is provided which selectively communicates an internal space of the ladle with an atmosphere. After the molten metal is introduced into the ladle through the intake/discharge port, the space is shut off from the atmosphere. A cross-sectional area of the intake/discharge port is in a range of from 28 to 80 mm.sup.2. The lower limit of the cross-sectional area of the intake/discharge port is sufficient to allow the molten metal to be flowed into the ladle, and the upper limit thereof is sufficient to prevent the molten metal in the ladle from dripping therefrom. Thus, a small amount of the molten metal can be rapidly and accurately casted.

Automatic molten metal supplying device

A metal mold cooling device capable of employing a cooling pipe having a small diameter insertable into a cooling hole having a small diameter, and capable of performing fine supply control of a cooling liquid to the metal mold for fine temperature control thereto. A cooling pipe is connected to a compressed air source through a pipe and a first change-over valve. Further, the pipe is connected to a branch pipe to which a second change-over valve is connected. A hermetic cooling liquid tank connected to a water source is connected to the second change-over valve. A third change-over valve is provided between the compressed air source and the cooling liquid tank so as to apply pneumatic pressure onto a surface of the cooling liquid in the cooling liquid tank. Since the cooling liquid tank is provided in addition to the water source, pneumatic pressure from the compressed air source can be utilized. The cooling liquid in the cooling liquid tank is compressed and is supplied to the cooling pipe. Therefore, spraying is achievable even by a cooling pipe having a small diameter. Further, supply of the cooling liquid can be finely controlled by controlling valve opening timing of each of the change-over valves.

Metal mold cooling device

An automatic molten metal supplying device and supplying method capable of promoting discharge of molten metal retained in a ladle during pouring into an injection sleeve of a die-casting machine, and capable of preventing a residual molten metal from being suspended from the intake/discharge port. A ladle is selectively communicatable with an atmosphere by the opening/closing unit. The opening/closing unit is connected to a molten metal pressurizing mechanism 20 and a residual molten metal removing mechanism 30 through pipes. At the time of pouring, small volume or low pressure fluid is introduced into the ladle by means of the molten metal pressurizing mechanism through the opening/closing unit. After completion of the pouring, large volume or high pressure fluid is introduced into the ladle by the residual molten metal removing mechanism. Since low volume or low pressure fluid is applied into the ladle during pouring, the molten metal can be smoothly discharged from the ladle. After the pouring, since large volume or high pressure fluid is applied into the ladle, residual molten metal in the ladle can be discharged therefrom, and no molten metal suspension from the intake-discharge port occurs. Thus, casting period can be reduced, and clean working condition can be provided.

Automatic molten metal supplying device and method for supplying the

A gas venting arrangement in a high speed injection molding apparatus such as a high speed die casting machine. The gas venting arrangement includes a gas vent control valve which is closable at an optimum timing and at high speed. This valve closure is achievable by providing an improved combination of a control circuit and a valve driving mechanism. The control circuit is connected to a molten metal sensor and sends a high voltage output drive signal to the valve driving mechanism when the sensor detects a first molten metal or a metal splash. The valve driving mechanism includes an electromagnetic valve connected to a pneumatic source and a pneumatically operated valve connected between the electromagnetic valve and the gas vent control valve. The pneumatically operated valve is also connected to the pneumatic source. The electromagnetic valve performs prompt change-over operation upon receiving the drive signal, and supplies driving pneumatic pressure to the pneumatically operated valve. The pneumatically operated valve performs prompt change-over operation upon receiving the driving pneumatic pressure for promptly applying pneumatic pressure to the gas vent control valve, to thereby close the same at high speed and at optimum timing without delay.

Gas venting arrangement in high speed injection molding apparatus and

Disclosed is a gas venting arrangement in an injection molding apparatus, and a method for venting gas out of the injection molding apparatus. The gas venting arrangement includes mold halves formed with a gas vent passage in fluid communication with a mold cavity and positioned downstream thereof, a gas vent control valve disposed at a downstream end portion of the vent passage, a detection member disposed at the vent passage for detecting injected material exceeding over the mold cavity, a valve driving mechanism connected to the gas vent control valve, and an electric control means connected between the detection member and the valve driving mechanism. The detection member generates a detection signal upon contact with the injected material and the valve driving mechanism is operated in response to the detection signal through the electric control means to operate the vent control valve.

Gas venting arrangement in injection molding apparatus and method for

A deflator for injection molding in a cavity. Two exhaust passages connect the cavity to a detection valve and an exhaust valve, which is being pumped. The exhaust passages are arranged so that the molten metal reaches the detection valve before the exhaust valve. Closing of the detection valve triggers the pneumatic closing of the exhaust valve. Also included in the invention is a bounce reduction means for the exhaust valve and a rockable connection for approaching the deflator to the mold.

Growing community of inventors

Fuchu, Japan

Noriyoshi Yamauchi