JP2011115811A - Method for controlling die casting machine - Google Patents

Abstract

A method for controlling a die casting machine with improved product productivity is provided.
A mold opening / closing process for opening / closing a mold using a servo motor for opening / closing the mold as an electric power source, and a molten metal in a mold cavity closed using an servo motor for injection driving as an electric power source. An injection process for injection filling, a core advancing / retreating process for moving the core 15 back and forth in the mold cavity using the hydraulic unit 17 as a hydraulic power source, and a squeeze pin 16 in the mold cavity using the hydraulic unit 17 as a hydraulic power source And a squeeze-pin advance / retreat process for advancing and retreating, wherein the core 15 retreating process is executed in parallel during the mold opening process and the mold closing process. The squeeze pin retracting step of the squeeze pin 16 is executed in parallel. Thereby, the molding cycle time can be shortened, and the production efficiency of the product can be improved.
[Selection] Figure 4

Description

  The present invention relates to a method for controlling the operation of a die casting machine, and in particular, among a plurality of processes performed in one cycle, a process using a hydraulic power source and a process using an electric power source are executed in parallel to reduce the molding cycle time. The present invention relates to a control method for a die casting machine which is shortened.

  Conventionally, there is a die casting machine that obtains a cast product by injecting and filling a molten metal material into a cavity of a mold. In such a die casting machine, a core may be provided in the mold in order to form a complicated shape such as a recess or a hole in the product. There is known a squeeze pin that press-fits into a cavity filled with a molten metal material when the molten metal is filled to prevent the product from being drawn or forming nests.

  In a conventional general die casting machine having a core and a squeeze pin, a mold opening / closing process for opening and closing the mold, a core advancing / retreating process for inserting / removing the core into / from the mold cavity, and a squeeze The squeeze pin advance / retreat process for inserting / removing the pin into / from the mold cavity commonly uses the hydraulic power source of a single hydraulic unit made up of accumulated accumulator, etc., and switches the flow rate adjustment switching valve in the hydraulic circuit, etc. It has been generalized that the operations of each process are controlled at different timings, and the plurality of processes are repeatedly executed every cycle, so that the cast product was mass-produced. In order to improve the process, one of the plurality of processes performed in one cycle is being executed, and the other processes are performed in parallel. It is to, it is known to shorten the time in one cycle.

  Patent Document 1, which is the same as the applicant of the present application, discloses an injection molding machine in which a mold opening / closing operation and an ejecting operation for taking out a molded product are executed in parallel in an injection molding machine to shorten a molding cycle. A control method is disclosed. Patent Document 2 discloses a squeeze pin actuating device that squeezes a pin into a die cavity of a die casting machine. Patent Document 3 discloses a die casting machine that drives a core by a hydraulic cylinder device. Is disclosed.

Japanese Patent No. 3037932 JP 2004-154805 A JP 2009-006390 A

  In a die casting machine that operates a mold apparatus that performs a mold opening / closing process, a core advance / retreat apparatus that performs a core advance / retreat process, and a squeeze pin advance / retreat apparatus that performs a squeeze pin advance / retreat process by commonly using the single hydraulic power source described above. Therefore, it is necessary to control the switching of the hydraulic path using the flow rate adjustment switching valve as each process is executed. Therefore, a time lag occurs due to the switching operation, and it is suitable for shortening the cycle time. There is no actual situation. Further, if a plurality of processes are executed in parallel using a single hydraulic power source, in a general die casting machine, a hydraulic power source using a hydraulic circuit is used from the viewpoint of cost reduction. As a result, the hydraulic control (hydraulic path switching and flow rate control) has become more complicated, making it difficult to control the operation of each process at the same time. Therefore, in the conventional die casting machine mainly composed of a hydraulic power source, it is not put into practical use that a plurality of processes are executed in parallel and the cycle time is shortened like an injection molding machine. It was the current situation.

  The present invention has been made in view of the above problems, and a die casting machine is provided with an electric power source in addition to a conventionally employed hydraulic power source, and includes a plurality of steps executed during one cycle of the die casting machine. Among them, to provide a method for controlling a die-casting machine that improves the productivity of products by preventing the occurrence of malfunctions by simultaneously executing the process by the hydraulic power source and the process by the electric power source, and shortening the molding cycle time. Objective.

Invention of the control method of the die-casting machine concerning Claim 1
A mold opening and closing process for opening and closing the mold using the servo motor for opening and closing the mold as an electric power source;
An injection process of injecting and filling molten metal into a mold cavity closed with an injection drive servomotor as an electric power source;
A control method of a die casting machine comprising: a core advancing / retreating step of inserting and removing a core into and from a cavity of the mold using a hydraulic unit as a hydraulic power source,
A core retraction step for retreating the core inserted in the cavity of the mold by driving the hydraulic unit during the mold opening process by driving the servo motor for opening and closing the mold, The core retracting process and the mold opening process are executed in parallel.

The invention of the method for controlling a die-casting machine according to claim 2 is described in claim 1,
With a hydraulic unit that is the same hydraulic power source as the core advance / retreat step as a hydraulic power source, a squeeze pin advance / retreat step for inserting / removing a squeeze pin into / from the cavity of the mold,
The mold opened by the drive of the mold opening / closing servo motor is inserted into the cavity of the mold by the drive of the hydraulic unit at the start of the mold closing process when the mold closing process starts. The squeeze pin retracting process of the squeeze pin is started simultaneously, and the squeeze pin retracting process and the mold closing process are executed in parallel.

  According to the invention of the control method of the die casting machine, the core retraction process and the mold opening process can be executed in parallel to shorten the molding cycle time of the die casting machine that is repeatedly operated. Therefore, the mass production efficiency of the product can be improved, and as a result, the cost of the product can be reduced, and the value becomes remarkable.

  Furthermore, since the squeeze pin retracting process and the mold closing process can be performed in parallel, the molding cycle time can be further shortened. Therefore, the mass production efficiency of the product can be further improved, and as a result, the cost of the product can be greatly reduced, and its value becomes much greater.

  Furthermore, in the conventional die casting machine, the power source for performing the mold opening / closing process and the power source for performing the core advance / retreat process, etc., commonly use a single hydraulic power source (hydraulic unit). In order to execute the processes in one cycle in parallel, there was a cause of malfunction due to the complicated control, but not only the hydraulic power source such as the hydraulic unit conventionally used in the die casting machine but also electric By providing this power source, it becomes possible to execute the processes in parallel at high speed with an accurate operation without malfunctioning, and as a result, it is possible to provide a die casting machine adapted to high cycle.

It is a schematic block diagram of the die-casting machine which shows the state which retracted the core in the state which opened the metal mold | die, and advanced the squeeze pin. It is a schematic block diagram of the die-casting machine which shows the state which advanced the core and closed the squeeze pin with the mold closed. It is a schematic block diagram of the die-casting machine which shows the state which advanced the core and the squeeze pin in the state which closed the metal mold | die. It is a schematic block diagram of the die-casting machine which shows the state which has retracted the core from the cavity of the mold during the mold opening process of the mold.

  Embodiments of the present invention will be described below with reference to FIGS. Of course, it goes without saying that the present invention can be easily applied to configurations other than those described in the embodiments without departing from the spirit of the invention.

  As shown in FIG. 1, a die casting machine 1 includes a mold apparatus 2 and an injection apparatus 3 as main components. In the former mold apparatus 2, a fixed die plate to which a fixed mold 4 is attached. 5. A movable die plate 7 to which a movable mold 6 is attached, a mold opening / closing servo motor 8, a toggle link mechanism 9 and the like are provided, and the toggle link mechanism 9 is bent using the mold opening / closing servo motor 8 as an electric power source. Thus, the movable mold 6 is opened and closed with respect to the fixed mold 4.

  The latter injection device 3 includes an injection sleeve 10, an injection plunger 11, an injection drive servo motor 12, a ball screw mechanism 13 and the like in the injection sleeve 10, and the injection drive servo motor 12 is electrically driven. As a source, the injection plunger 11 is advanced and retracted in the injection sleeve 10 via the ball screw mechanism 13, and a molten metal material poured into the injection sleeve 10 by a hot water supply device (not shown) is The injection plunger 11 is moved forward by the drive of the injection drive servo motor 12 so as to be pressure-fed to the cavity of the closed mold to perform injection filling.

  15 is a core inserted into and removed from the mold cavity in order to form a complicated shape such as a recess or a hole, and the squeeze pin 16 is a molten metal to prevent the product from being drawn or forming a nest. A squeeze pin that is press-fitted into a cavity filled with material and is inserted into and removed from the cavity of the mold. The core 15 and the squeeze pin 16 are provided in the movable mold 6, and the squeeze is performed via the hydraulic circuit 19 by the switching operation of the flow rate adjustment switching valve 18 using the hydraulic unit 17 as a hydraulic power source as a common power source. Each of the pin 16 and the core 15 is moved back and forth. Note that the squeeze pin 16 and the core 15 in the present embodiment are controlled by the control means 20 described later so that the operations of the squeeze pin 16 and the core 15 are not performed in parallel to prevent malfunction. Also, the hydraulic unit 17 includes an accumulator 23 that moves the squeeze pin 16 and the core 15 forward and backward through at least the squeeze pin hydraulic cylinder 21 and the core hydraulic cylinder 22, and hydraulic fluid to the accumulator 23. Is provided with a hydraulic pump 24 for supplying hydraulic fluid and a tank 25 for storing hydraulic oil, and the control means 20 detects whether or not the pressure necessary for driving the squeeze pin 16 and the core 15 is accumulated in the accumulator 23. When the pressure in the accumulator 23 is equal to or lower than a predetermined pressure, the hydraulic pump is controlled by the control means 20. 4 accumulator hydraulic oil in the accumulator 23 is supplied (charged) is performed through, and controls the pressure in the accumulator 23 to stop the hydraulic pump 24 at the stage of reaching a predetermined pressure.

  Next, the operation of one cycle of the die casting machine 1 will be further described with reference to FIGS. In the die casting machine 1 of the present embodiment, a core advancing / retreating process (core advancement process and core retreating process) using the hydraulic unit 17 as a hydraulic power source, and the hydraulic unit 17 as a hydraulic power source. Squeeze pin advance / retreat process (squeeze pin advance process and squeeze pin retract process) of the squeeze pin 16, mold opening / closing process (mold opening process and mold closing process) using the mold opening / closing servomotor 8 as an electric power source, and injection A die casting machine in which at least an injection process is performed in which a movable servo plunger 12 is moved forward by using a drive servo motor 12 as an electric power source, and a molten metal poured into the injection sleeve 10 is injected and filled into a cavity of a mold. 1 and these processes are executed at a predetermined timing by the control means 20 comprising a CPU. It has been. First, as shown in FIG. 1, when the core 15 is retracted and the squeeze pin 16 is advanced, the core advancement process of the core 15 is executed, and when the process ends, the mold is opened at that timing. The mold closing process of the mold being started is started, and at the same time, a squeeze pin retreating process is performed in which the squeeze pin 16 in the forward state is retreated, and the squeeze pin retreating process and the mold closing process are performed in parallel. When the mold closing process and the squeeze pin retreating process are completed, the molten metal poured into the injection sleeve 10 from a molten metal device (not shown) is injected into the mold cavity by the advancement of the injection plunger 11. Filled and an injection process (injection plunger advance process) is performed (state shown in FIG. 2).

  Subsequently, when a predetermined amount of the molten metal is filled in the mold cavity by executing the injection process, the pressure is increased by the injection plunger 11 with respect to the filled molten metal, and the predetermined set holding pressure is reached. This is detected by a detection sensor (not shown), and the control unit 20 performs pressure holding control for a predetermined time.

  Subsequently, as shown in FIG. 3, the squeeze pin 16 is advanced and pressed into the cavity filled with the molten metal material by driving the hydraulic unit 17 as shown in FIG. 3 (squeeze pin advance step). Next, after a predetermined time has elapsed after the molten metal has been cooled and solidified, the advanced squeeze pin 16 is retracted (same as the state shown in FIG. 2).

  When the retraction of the squeeze pin 16 is completed, at the same time, the mold opening process of the mold in the mold closed state is executed (retracting the movable mold). As shown in FIG. Inside, the core retraction process of the core 15 inserted in the cavity of the mold by the drive of the hydraulic unit 17 is executed in parallel.

  Subsequently, when the mold opening process of the mold and the core retracting process of the core 15 are completed, then an injection plunger retracting process for retracting the injection plunger 11 is performed, and after the metal product is taken out from the mold, A mold release agent is sprayed from a spray device (not shown) onto the mold surface that has formed the cavity, and the squeeze pin advancement process is executed again (state shown in FIG. 1). The series of steps described above is set as one cycle, and the metal product is mass-produced by repeatedly performing the operation.

  According to the control method of the die casting machine 1 of the present embodiment as described above, the electric power source that operates the mold opening / closing process and the hydraulic power source that operates the core advance / retreat process and the squeeze pin advance / retreat process are separated from each other. As a source, when the process executed by the hydraulic power source is not executed in parallel, but when the process and the process by the electric power source are executed in parallel by the hydraulic power source, the control means 20 for controlling the operation of each process in an integrated manner. However, each process can be controlled individually (speed control, start timing control, etc.), the mold opening / closing process of the electric drive source, and the core retracting process of the hydraulic power source (squeeze pin retracting process) Can be accurately executed without malfunction.

  Furthermore, a mold opening / closing process for opening / closing the mold using the mold opening / closing servo motor 8 as an electric power source, and injection filling and filling the mold cavity with the injection driving servo motor 12 as an electric power source. An injection step, a core advancing / retreating step for inserting / removing the core 15 into / from the mold cavity using the hydraulic unit 17 as a hydraulic power source, and a squeeze in the mold cavity using the hydraulic unit 17 as a hydraulic power source And a squeeze pin advance / retreat process for inserting / removing the pin 16 (advance / retreat). During the mold opening process by driving the mold opening / closing servo motor 8, the hydraulic unit 17 is driven to insert the pin 16 into the mold cavity. The core retracting process and the mold opening process are performed in parallel by executing the core retracting process for retracting the core 15 that has been retracted, and further, the mold is opened by driving the mold opening / closing servo motor 8. At the start of the mold closing process in which the mold is moved to the mold closing process, the squeeze pin retraction process of the squeeze pin 16 inserted in the cavity of the mold is simultaneously started by driving the hydraulic unit 17 to retreat the squeeze pin. Since the process and the mold closing process are performed in parallel, the core retreating process is performed in the mold opening process, while the squeeze pin retreating process is performed in the mold closing process. The molding cycle time in one cycle of the die casting machine 1 can be shortened by about 3 seconds with respect to the die casting machine that does not execute the processes that have been conventionally used in parallel. Therefore, the mass production efficiency of the product can be improved, and as a result, it can contribute to the cost reduction of the product.

  Furthermore, in a conventional die casting machine, the power source that performs the mold opening / closing process and the power source that performs the core advance / retreat process, etc. commonly use a single hydraulic power source (hydraulic unit). In order to execute the processes in parallel in one cycle, there was a cause of malfunction due to complicated control, but not only the hydraulic power source such as the hydraulic unit conventionally used in die casting machines but also electric By providing this power source, it is possible to execute the above processes in parallel at high speed with an accurate operation without malfunction, and thus it is possible to provide a die casting machine adapted to high cycle.

  As mentioned above, although an example of this embodiment was explained in full detail, this invention is not limited to the said embodiment, A various deformation | transformation implementation is possible within the range of the summary of this invention. In the present embodiment, the operation of the core advance / retreat process and the squeeze pin advance / retreat process is switched by switching the flow rate adjustment switching valve 18 in the hydraulic circuit 19 using a single hydraulic power source. However, although the cost increases, a hydraulic power source for the core advance / retreat process and the squeeze pin advance / retreat process may be provided separately.

1 Die-casting machine 4 Fixed mold (mold)
6 Movable mold (mold)
8 Servo motor for mold opening / closing 12 Servo motor for injection drive 15 Core 16 Squeeze pin 17 Hydraulic unit

Claims (2)

A mold opening and closing process for opening and closing the mold using the servo motor for opening and closing the mold as an electric power source;
An injection process of injecting and filling molten metal into a mold cavity closed with an injection drive servomotor as an electric power source;
A control method of a die casting machine comprising: a core advancing / retreating step of inserting and removing a core into and from a cavity of the mold using a hydraulic unit as a hydraulic power source,
A core retraction step for retreating the core inserted in the cavity of the mold by driving the hydraulic unit during the mold opening process by driving the servo motor for opening and closing the mold, A control method for a die casting machine, wherein a core retreating process and the mold opening process are executed in parallel. With a hydraulic unit that is the same hydraulic power source as the core advance / retreat step as a hydraulic power source, a squeeze pin advance / retreat step for inserting / removing a squeeze pin into / from the cavity of the mold,
The mold opened by the drive of the mold opening / closing servo motor is inserted into the cavity of the mold by the drive of the hydraulic unit at the start of the mold closing process when the mold closing process starts. 2. The method of controlling a die casting machine according to claim 1, wherein a squeeze pin retraction process of a squeeze pin is started simultaneously, and the squeeze pin retraction process and the mold closing process are executed in parallel.

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