Toshiba Kikai Kabushiki Kaisha

Toshiba Machine Co., Ltd.

Keihin Corporation

Norihiro Iwamoto

Masayuki Takamura

Hiroyuki Tsuboi

Toshihiko Kaneko

Shinobu Kodama

Tai Matsuda

Masaru Kobayashi

Hiroshi Yokoyama

Yutaka Nakamura

Makoto Tsuji

Fumihiro Sakuma

Kimio Suzuki

Yukio Mizota

Tetsuya Uehara

Hiroshi Kitamura

Noboru Fujiyoshi

Yoshitami Hakata

Akihiko Tsuda

Hiroshi Iga

A squeeze pin circuit is installed to a direction switching valve. The direction switching valve is configured to switch a direction of hydraulic pressure to a core cylinder. The squeeze pin circuit is configured to drive a squeeze pin. The squeeze pin is configured to partially pressurize molten metal filled in a cavity. The squeeze pin circuit includes a squeeze pin cylinder and a flow rate adjusting unit. The squeeze pin cylinder is coupled to the direction switching valve to drive the squeeze pin. The flow rate adjusting unit is installed on a hydraulic pressure path. The hydraulic pressure path couples the direction switching valve to a head side of the squeeze pin cylinder. The flow rate adjusting unit is configured to ensure pressure compensation and temperature compensation.

Squeeze pin circuit for die casting and hydraulic unit

A method for controlling injection in a die casting machine and apparatus for the same capable of producing high-quality die-casting products, which are not produced with fins, even in a high-speed cast or the use of the die with a low precision. A pressurizing controllable valve (21) is a flow adjustable type. A main spool (211) is structured to have a two-way valve (212) with a check-valve function and a position detector (213) for controlling servo, so that the flow of hydraulic fluid charged to a pressurizing cylinder device 20 is not controlled to be switched between ON-OFF but is allowed to adjustably flow, and a pressurizing process is controlled in response to a fin critical curve, thereby fins are previously avoided to be produced, thus producing the high-quality die-casting productions.

Method for controlling injection in a die casting machine and apparatus

A dynamic variation of a cavity pressure (P, Vac) in a die cavity (17) defined between a stationary die (3) and a movable die (7) is supervised during an injection of molten metal (M) by a pressure supervisory system (27, 29, 43, 45, 53, 75, 83, 95) that includes a pressure detection path (27,37) communicating with the die cavity, a pressure sensor (73) for detecting the cavity pressure through the pressure detection path and a processor (75) for processing detection data of the cavity pressure, and the stationary die (3) is formed with a pressure detection port (27) that constitutes part of the pressure detection path.

Die casting machine with pressure supervisory system supervising cavity

An injection device of a die casting machine including an injecting cylinder, in which a piston connecting to a piston rod is slidably thrust into a cylinder body and in which pressurized oil is fed to the side of the piston from a pressurized oil source and flows out from the side of the piston rod, and a servo valve controlling an injection speed of the injection cylinder device by controlling the amount of flow of pressurized oil that flows out from the injecting cylinder. The servo valve is directly attached to the cylinder body of the injecting cylinder and a flow channel connecting the injecting cylinder and servo valve is shortened.

Injection device of a die casting machine

A method for controlling the injection of a die casting machine in which immediately after molten metal is injected into a cavity of metal molds at a high speed, the pressure oil in the chamber at the rod side of an injection cylinder is discharged into a tank side to commence the increase in pressure. A reference point for a switching-over position where a high speed charge is switched over to the increase in pressure is determined by computing a necessary length along the path for keeping the increased charging pressure on the basis of the supplied molten metal quantity during the previous injection process and subtracting the length from the length between the starting position and the position of limit of the forward movement at the previous injection process.

Method for controlling injection of die casting machine

A method of precisely controlling the stroke of movement of at least one squeeze pin in a die casting machine, which pressurizes locally the molten metal charged into a cavity of a metal mold. The method comprises detecting a flow rate of the pressure oil at the back pressure side of a squeeze pin cylinder which drives the squeeze pin of the die casting machine, calculating the stroke of the squeeze pin on the basis of the detected flow rate, and controlling the stroke of the squeeze pin toward a target value with the detected flow rate as a parameter.

Squeeze pin control system in die casting machine

A method of controlling vacuum in vacuum die-casting and a vacuum control system for performing the same adjusts the time to open a vacuum valve to start degassing in connection with the position of an injection plunger to control vacuum in a cavity so that gases may not be involved in a molten metal injected into the cavity. The method comprises opening the vacuum valve to start degassing the cavity upon the advancement of the injection plunger to a first position. The vacuum in a vacuum system is measured upon the arrival of the injection plunger at a second position immediately before a final position where the injection plunger completes the injection of the molten metal. A measured vacuum is compared with a predetermined reference vacuum. The first position is shifted by a predetermined distance toward the die when the measured vacuum is higher than the reference vacuum or by a predetermined distance away from the die when the measured vacuum is lower than the reference vacuum to set a corrected first position. The vacuum valve is opened when the injection plunger arrives at the corrected first position in the next injection cycle.

Method of controlling vacuum in vacuum die-casting and vacuum control

A method and an apparatus of controlling the injection of a die casting machine can be used for any existing metal molds without requiring the use of a metal charge front sensor and shift the speed of advancement of the plunger rod to initiate a forced speed reduction of the plunger at a right timing regardless of variances in the charge of molten metal so that the machine may stably produce quality die cast products. Such a method of controlling the injection of a die casting machine for injecting molten metal fed to an injection sleeve into a metal mold by means of an injection plunger 100 to charge the metal mold with molten metal comprises the steps of detecting the pressure of the plunger rod charging the metal mold with molten metal; determining that the molten metal has arrived the gate section, or injection port, of the metal mold at a time when the detected pressure gets to a predetermined value; and controlling the injection speed on the basis of the time.

Method and apparatus of controlling injection of die casting machine

Operation can be switched from low- or high-speed injection process to intensified-pressure injection process by using only one accumulator, and an injection cylinder is composed of a single-acting cylinder, so that the space can be saved, and intensified-pressure surge can be reduced. A coaxial small-diameter portion is formed on the pressure surface side of a piston of the accumulator, a hydraulic oil discharge passage having an inside diameter corresponding to the outside diameter of the small-diameter portion is provided coaxial with the piston, and a passage is provided for guiding intensified-pressure oil in a cylinder chamber of the accumulator.

Injection apparatus for a die casting machine

A stroke S of a squeeze pin under no load condition of a squeeze pin cylinder for driving the squeeze pin is detected. A value (S-.alpha.) obtained by subtracting a small value .alpha. from the detected stroke S of the squeeze pin is determined as a set stroke of the squeeze pin. After a predetermined waiting time has elapsed from when melted metal is charged into a cavity completely, the squeeze pin is advanced. Here, the actual stroke Sf of the squeeze pin is detected, and the detected stroke Sf is compared with set stroke (S-.alpha..+-..beta.), where .beta. is an allowable deflection. As the result of comparison, if Sf oversteps the set limits (S-.alpha..+-..beta.), at least one of parameters (the pressure and the flow rate of hydraulic fluid supplied to the squeeze pin cylinder and the waiting time) is corrected, so that the detected stroke value Sf approaches the set stroke (S-.alpha.) for the succeeding casting cycle.

Squeeze pin control method and apparatus for die casting machine

A vacuum-controlling system for controlling the degree of vacuum in the vacuum system of a vacuum die-casting machine operates to: detect the degree of vacuum H at the instant of closure of the vacuum valve to the die mold cavity; compare the detected degree of vacuum H with a preset degree of vacuum Ho; correct a first position of the injection plunger for opening the vacuum valve by moving the first position in the advancing direction of the plunger by a specific distance in the case where H is higher than Ho; and correct the first position in the retracting direction of the plunger by a specific distance in the case where H is lower than Ho. By thus automatically correcting the position of the plunger for opening the vacuum valve to the optimum state, the formation of cavities or blowholes in the die-cast product is prevented, and at the same time, by maintaining the degree of vacuum in a specific state, the product quality is stabilized.

Method and apparatus for vacuum die casting

An apparatus for displaying casting-data in a die-cast machine having a plurality of sensors which gather data values such as speed, pressure and temperature. A converter processes signals from sensors, and an input-calibration mechanism may be provided for correcting the processed signals and for issuing detected data. A casting-cycle data processing mechanism may be provided for displaying data items such as an injection speed or an injection pressure every casting cycle, based on the detected data. A casting control data processing mechanism may also be provided for displaying shot-time items and fluctuations through repeated injection cycles to monitor casting operation, where displays are based on the detected data from the input-calibration mechanism.

Method of and apparatus for displaying casting-data in die-cast machine

An injection speed control valve for controlling the speed of flow of operating fluid from an operating fluid source of the die-casting machine to an injection cylinder, a pressure compensation valve for controlling the pressure of the operating fluid to a predetermined differential valve pressure to be coupled to the injection speed control valve, a bypass duct communicating the operating fluid source and the injection speed control valve, a logic valve for on-off controlling the flow of the operating fluid through the bypass duct, and a solenoid valve for on-off operating the logic valve, are provided. The speed of injection by the injection cylinder is controlled by switching the logic valve with the solenoid valve while maintaining a predetermined opening degree of the injection speed control valve.

Method of and apparatus for injection speed control in die-casting

A stroke-end position of an injection cylinder of the die cast machine is detected and a position of the injection cylinder for sending a boosting-signal is set. This position is a predetermined standard boost stroke distance from the stroke-end position. When the injection cylinder reaches the position for sending the boosting-signal in the casting cycle, an oil-pressure intensifier is advanced. In this method, before casting is performed, a value representing a stroke after slowing-down and a setting value of the plunger stopping position are determined and the start point for slowing-down is calculated by subtracting the value of the stroke after slowing down from the setting value.

Injection control method of die cast machine

In a press casting machine a molten material enclosed in a cavity of a mold is squeezed by a pressure pin, the pressure pin is controlled by automatically controlling the start timing thereof. Namely, an optimum stroke of the pressure pin is preliminarily set and an actual stroke thereof is detected. The detected stroke of the pressure pin is compared with the optimum stroke thereof and a start timing of the pressure pin is corrected or modified so that the stroke thereof is made optimum. When the detected stroke of the pressure pin is smaller than the set stroke thereof, the start timing of the pressure pin is corrected so that a timing for starting the pressure pin advances and, on the contrary, when the detected stroke of the pressure pin is larger than the set stroke thereof, the start timing of the pressure pin is corrected so that a timing for starting the pressure pin is delayed.

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Zama, Japan

Norihiro Iwamoto