Injection molding machine, control device, and program

Abstract

In a manufacturing process of a molded article in an injection molding machine, supply of a molding material is controlled according to the amount of the molding material used in a molding cycle of the molded article, and unnecessary supply of the molding material is suppressed. An injection molding machine is provided with: an injection device that injects a molding material into a mold of a molded article; and a control device for controlling the supply of the molding material to the injection device, the control device setting, in accordance with the number of times of implementation of a molding cycle of a molded article that can be implemented using the molding material held in the injection device, the number of times of implementation before stopping the molding cycle, i.e., the number of times of implementation before stopping the molding cycle. The supply of the molding material to the injection device is stopped at a point in time at which the number of times of implementation before the stop is traced from the stop of the molding cycle.

Description

Technical Field

[0001] This application claims the benefit of priority based on Japanese Patent Application No. 2023-197661 filed on November 21, 2023. The entire contents of the Japanese Patent Application are incorporated herein by reference.

[0002] The invention relates to an injection molding machine, a control device and a program. Background Art

[0003] In an injection molding machine, when a molded product or a resin serving as a molding material is changed, a process of removing the molding material remaining inside the injection molding machine used in the previous production of the molded product is performed.

[0004] Patent document 1 discloses an injection molding machine comprising: a clamping device on which a mold device is installed; and a control unit, which performs the following operations and other preparatory operations: in the process of replacing the mold device installed on the clamping device, adjusting the clamping force by adjusting the mold thickness of the clamping device according to the mold device of the next mold; in the process of replacing the mold device, clearing the molding material of the injection device; in the process of replacing the mold device, starting the temperature adjustment of the mold device of the next mold.

[0005] Patent Document 1: Japanese Patent Application Publication No. 2021-160275

[0006] Since the removed molding material is unnecessary for manufacturing the molded product, it is preferred to reduce its amount as much as possible. In order to reduce the amount of the removed molding material, it is necessary to stop the supply of the molding material at an appropriate time in the manufacturing process of the molded product. Summary of the invention

[0007] An object of the present invention is to control the supply of molding material according to the amount of molding material used in a manufacturing process of a molded product in an injection molding machine, thereby suppressing unnecessary supply of molding material.

[0008] One embodiment of the present invention is an injection molding machine, characterized in that it comprises: an injection device for injecting molding material into a mold of a molded product; and a control device for controlling the supply of molding material to the injection device, the control device sets a pre-stop action amount representing the amount of action performed before stopping the action of the injection device for manufacturing the molded product based on a parameter for determining the number of molded products that can be manufactured using the molding material retained in the injection device, and stops supplying molding material to the injection device at a time point tracing back the pre-stop action amount from when the action of the injection device is stopped.

[0009] Effects of the Invention

[0010] According to one aspect of the present invention, in a manufacturing process of a molded product in an injection molding machine, supply of a molding material can be controlled according to the amount of the molding material used, thereby suppressing unnecessary supply of the molding material. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a diagram showing the structure of an injection molding machine to which the present embodiment is applied.

[0012] Figure 2 It is a diagram showing the structure of a control device.

[0013] Figure 3 It is a diagram showing the structure of a data processing device.

[0014] Figure 4 It is a diagram showing a hardware configuration example of a control device and a data processing device.

[0015] Figure 5 It is a figure which shows the structure of an injection device.

[0016] Figure 6 This is a diagram showing a state in which the injection device holds the molding material.

[0017] Figure 7 This is a flowchart showing control of supplying molding material to the injection device.

[0018] In the figure: 10-injection molding machine, 20-injection device, 21-cylinder, 22-screw, 23-motor, 24-hopper, 25-heater, 26-check valve, 30-mold clamping device, 31-mold, 100-control device, 110-control unit, 120-molding condition setting unit, 130-storage unit, 200-data processing device, 210-data acquisition unit, 220-processing unit, 230-storage unit, 500-material supply device. DETAILED DESCRIPTION

[0019] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0020] <Device Structure>

[0021] Figure 1 1 is a diagram showing the structure of an injection molding machine to which the present embodiment is applied. The injection molding machine 10 includes an injection device 20 , a mold clamping device 30 , a control device 100 , and a data processing device 200 .

[0022] The injection device 20 is configured to include a cylinder for heating the molding material, a screw that can rotate in the cylinder and can move forward and backward along the axial direction, a rotary motor that drives the screw in the rotational direction, and a motor that drives the screw in the axial direction. The details of the structure of the injection device 20 will be described later. The molding material is, for example, a resin. The injection device 20 injects the molding material that is heated in the cylinder and becomes liquid by extending the screw in the direction (forward) from the injection device 20 toward the clamping device 30 while rotating, and fills it into the mold of the clamping device 30 arranged in front of the injection device 20. In the manufacturing process of the molded product, the injection device 20 performs, for example, a metering process, a filling process, a pressure holding process, etc. The filling process and the pressure holding process are also collectively referred to as an injection process.

[0023] The mold clamping device 30 is configured to include a mold, a fastening mechanism for fastening the mold, a motor for driving the fastening mechanism, and the like. The mold clamping device 30 closes the mold and receives the molding material injected from the injection device 20 into the mold. At this time, the mold clamping device 30 fastens the mold using the fastening mechanism so that the mold will not open (mold clamping) due to the filling of the molding material. The molding material filled into the mold is solidified to generate a molded product. Then, the mold clamping device 30 can open the mold and take out the generated molded product. The mold clamping device 30 performs, for example, a mold closing process, a pressure increasing process, a mold clamping process, a decompression process, a mold opening process, and the like in the manufacturing process of the molded product.

[0024] The control device 100 is a device that controls the operation of the injection device 20 and the mold clamping device 30. The data processing device 200 is a device that processes data obtained as the injection device 20 and the mold clamping device 30 operate. Although not particularly shown in the figure, the control device 100 and the data processing device 200 are provided with an input device operated by a user to input commands or data, a display device that displays various screens such as an operation screen and an information prompt screen, and the like.

[0025] <Configuration of Control Device 100 >

[0026] Figure 21 is a diagram showing the structure of the control device 100. The control device 100 controls the actions of the injection device 20 and the mold clamping device 30. The control device 100 is realized by a computer, for example. The control device 100 includes a control unit 110, a molding condition setting unit 120, and a storage unit 130. The control device 100 controls the injection device 20 and the mold clamping device 30 to repeat the processes related to the manufacture of the molded product, thereby repeatedly manufacturing the molded product. The processes related to the manufacture of the molded product include a metering process, a mold closing process, a pressure increasing process, a mold clamping process, a filling process, a pressure holding process, a cooling process, a decompression process, a mold opening process, and an ejection process. Hereinafter, these processes related to manufacture are sometimes collectively referred to as "manufacturing processes". In addition, a series of actions for obtaining a molded product, such as the actions from the start of the metering process to the start of the next metering process in the above-mentioned manufacturing process, are referred to as "injection", "molding cycle", etc. In addition, the above-mentioned processes for manufacturing a molded product are only examples. For example, as a process performed by one injection, other processes not included in the above may be included.

[0027] The control unit 110 controls the injection device 20 and the clamping device 30 according to the control information. The control information includes conditions set by the user and fixed conditions. The conditions set by the user are generated, for example, based on information input by the user using an input device not shown. The control information includes, for example, molding conditions such as cylinder temperature (resin temperature), mold temperature, injection holding time, metering value, VP switching position, holding pressure, injection speed (filling speed), screw speed, screw back pressure, and clamping force. Regarding these molding conditions, multiple combinations are determined according to the molded product or mold. Hereinafter, the combination data of the molding conditions will also be referred to as a molding condition data set. The molding condition data set is prepared according to the type of molded product or mold, and is stored in the storage unit 130.

[0028] The control unit 110 uses the above-mentioned molding condition data set to control the injection device 20 and the mold clamping device 30 to implement the processes related to the manufacture (injection) of the molded product, including the above-mentioned processes. When starting to manufacture the molded product, the control unit 110 reads the molding condition data set corresponding to the molded product to be manufactured from the storage unit 130. Then, the control unit 110 controls the operation of the injection device 20 and the mold clamping device 30 based on the control information including the read molding condition data set. Specifically, the control unit 110 controls the injection device 20 and the mold clamping device 30 so that the data obtained from the injection device 20 and the mold clamping device 30 in the manufacturing process are consistent with the set value of the molding condition data set.

[0029] The molding condition setting unit 120 sets the molding conditions used in the control of the injection device 20 and the mold clamping device 30 by the control unit 110. The molding conditions are set by the molding condition setting unit 120 writing the molding condition data set into the control information stored in the storage unit 130. In addition, the molding conditions are set based on the information input by the user using the input screen described later. If the manufacturing process of the molded product is repeated, the state of the injection device 20 and the mold clamping device 30 changes, and the state change of the device 20, 30 affects the quality of the molded product (hereinafter referred to as "molding quality"). Therefore, in order to maintain the molding quality during the operation when mass-producing molded products, the molding condition setting unit 120 can automatically adjust the molding conditions.

[0030] The storage unit 130 stores control information used by the control unit 110 to control the injection device 20 and the mold clamping device 30. The control information includes a molding condition data set set by the molding condition setting unit 120. The molding condition data set is prepared in association with the molded product or mold of the manufacturing object. The storage unit 130 stores a molding condition data set for each molded product or each mold of the manufacturing object. In addition, the storage unit 130 stores information on molding conditions input by the user. The molding condition setting unit 120 writes the molding condition data set into the control information based on the information stored in the storage unit 130.

[0031] Although not shown in the figure, the storage unit 130 stores a program for the control unit 110 to control the injection device 20 and the mold clamping device 30, and a program for the molding condition setting unit 120 to set the molding conditions. Although the details will be described later, the processor in the control device 100 reads and executes the program stored in the storage unit 130, thereby realizing the functions of the control unit 110 and the molding condition setting unit 120.

[0032] <Configuration of Data Processing Device 200 >

[0033] Figure 3 2 is a diagram showing the structure of the data processing device 200. The data processing device 200 acquires and processes data obtained as the injection device 20 and the mold clamping device 30 perform the operations in the above-mentioned process related to the manufacture of the molded product. In addition, the data processing device 200 receives input operations performed by the user, generates information for the molding condition setting unit 120 of the control device 100 to set the molding conditions, and sends it to the control device 100. The data processing device 200 is realized by a computer, for example. The data processing device 200 includes a data acquisition unit 210, a processing unit 220, and a storage unit 230.

[0034] The data acquisition unit 210 acquires data of the processing object from the injection device 20 and the mold clamping device 30. Various sensors, detectors, etc. are installed on the injection device 20 and the mold clamping device 30. In addition, various measuring devices are sometimes connected to the injection device 20 or the mold clamping device 30. The data acquired using these sensors, detectors, measuring devices, etc. (hereinafter referred to as "acquired data") is information representing the molding results based on the injection device 20 and the mold clamping device 30, and can be used for quality management of molded products. Specifically, for example, it includes the weight of the molded product, the size of the molded product, the internal pressure of the mold, the minimum buffer position, the characteristic quantity of the waveform of the filling pressure, etc. These acquired data are actual values ​​obtained in the manufacturing process of the molded product. The data acquisition unit 210 receives the acquired data sent from the sensor, detector, or measuring device, and stores it in the storage unit 230.

[0035] The processing unit 220 processes the acquired data stored in the storage unit 230. Specifically, the processing unit 220 extracts representative values ​​of the acquired data in each process, generates time series data by time-series the acquired data in each process, and the like. In extracting the representative value, the processing unit 220 performs statistical processing such as calculating the average value, determining the range of values, and determining the maximum or minimum value on the acquired data.

[0036] The storage unit 230 stores the acquired data acquired by the data acquisition unit 210. As the data format of the acquired data stored in the storage unit 230, for example, binary, text, CSV (Comma Separated Values), INI, YAML (YAML Ain't Markup Language), JSON (JavaScript Object Notation), etc. can be used. By setting it as a data file based on these general data formats, the data file stored in the storage unit 230 can be exchanged with other information processing devices, or the data file acquired from the external device can be edited.

[0037] Although not shown, the storage unit 230 stores a program for the processing unit 220 to execute data processing. Although the details will be described later, the functions of the processing unit 220 can be realized by the processor in the data processing device 200 reading and executing the program stored in the storage unit 230.

[0038] <Hardware Configuration of Control Device 100 and Data Processing Device 200>

[0039] Figure 4 1 is a diagram showing a hardware configuration example of a computer 400 that realizes the control device 100 and the data processing device 200 . Figure 4The computer 400 shown has a processor 401 as a computing mechanism, a main storage device (main memory) 402 as a storage mechanism, and an auxiliary storage device 403. As the processor 401, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), and various other computing circuits can be used. The processor 401 reads the program stored in the auxiliary storage device 403 into the main storage device 402 for execution. As the main storage device 402, for example, a RAM (Random Access Memory) is used. As the auxiliary storage device 403, for example, a magnetic disk device or an SSD (Solid State Drive) is used. In addition, a display device 404 for displaying images and an input device 405 as an input mechanism for the computer to be operated by the user are connected to the computer 400. As the input device 405, for example, a keyboard or a mouse is used. In addition, Figure 4 The structure of the computer 400 shown is only an example, and the computer 400 used in this embodiment is not limited to Figure 4 For example, a nonvolatile memory such as a flash memory or a ROM (Read Only Memory) may be provided as a storage device.

[0040] In the control device 100 Figure 4 In the case of computer implementation shown, the functions of the control unit 110 and the molding condition setting unit 120 are implemented, for example, by the processor 401 reading and executing a program. The storage unit 130 is implemented by the auxiliary storage device 403, for example.

[0041] In the data processing device 200, Figure 4 In the case of computer implementation shown, the functions of the data acquisition unit 210 and the processing unit 220 are implemented, for example, by the processor 401 reading and executing a program. The storage unit 230 is implemented by the auxiliary storage device 403, for example.

[0042] <Supply and injection of molding material in the injection process>

[0043] Next, the supply and injection of the molding material in the injection process will be described. First, the structure of the cylinder, screw, and hopper responsible for injecting the molding material in the injection device 20 will be described, and the operation of these structures in the injection process will be described.

[0044] Figure 5 2 is a diagram showing the structure of the injection device 20. The injection device 20 includes a cylinder 21, a screw 22 provided in the cylinder 21, and a motor 23 for driving the screw 22. In addition, the injection device 20 includes: a hopper 24 for supplying a molding material into the cylinder 21; a heater 25 for heating the molding material in the cylinder 21 to melt it; and a check valve 26 for preventing the molding material in a liquid state from flowing back in the cylinder 21.

[0045] Figure 6 2 is a diagram showing a state in which the injection device 20 holds the molding material. A granular molding material M is stored in the hopper 24. In the injection device 20, when the motor 23 drives the screw 22 to rotate, the molding material M is transported from the hopper 24 to the front of the cylinder 21 along the groove of the screw 22. The molding material M is heated by the heater 25 while moving in the groove of the screw 22, and melts to become liquid. Then, when the motor 23 drives the screw 22 to extend it forward of the cylinder 21, the liquid molding material M accumulated in front of the cylinder 21 is injected and filled in the mold 31 (refer to Figure 5 ) In addition, the molding material M is supplied to the hopper 24 from the material supply device 500.

[0046] The check valve 26 provided near the front end of the screw 22 is configured to open when the screw 22 rotates to deliver the molding material M to the front of the cylinder 21, and to close when the screw 22 extends to the front of the cylinder 21. Thus, when the molding material M is injected by the injection device 20, the molding material M is prevented from flowing backward inside the cylinder 21.

[0047] After the manufacture of the molded product based on the injection molding machine 10 is completed, the injection device 20 removes (discharges) the remaining molding material M remaining inside the cylinder 21. Here, the molding material M that is removed is an unnecessary material that is not used to manufacture the molded product, so the less the amount, the better. Therefore, the supply of the molding material M is stopped at a stage before the end time of the manufacturing process, and the molding material M remaining inside the cylinder 21 is used to manufacture the molded product with the remaining several shots. On the other hand, if the supply of the molding material M is stopped too early, the molding material M inside the cylinder 21 is used up before the end of the manufacturing process, which may cause the number of shots that cannot reach the production target. The number of shots is the number of times the molding cycle is implemented when manufacturing a molded product.

[0048] Therefore, in the present embodiment, the time to stop the supply of the molding material M is calculated based on the amount of the molding material M that can be accumulated in the cylinder 21 and the hopper 24 and the amount of the molding material M used in one shot, and the supply of the molding material M is controlled. The calculation of the time to stop the supply of the molding material M is performed by, for example, the data processing device 200. The supply control of the molding material M based on the calculated time is performed, for example, by the control device 100 sending a control signal to the material supply device 500 to instruct the start and stop of the supply of the molding material M. Specifically, for example, the molding condition setting unit 120 of the control device 100 sets the supply control of the molding material M based on the calculation result of the time to stop the supply of the molding material M as one of the molding conditions, and the control unit 110 instructs the material supply device 500 to start and stop the supply of the molding material M according to the set content. In this case, the molding condition setting unit 120 is an example of a setting mechanism, and the control unit 110 is an example of a stopping mechanism.

[0049] <Determination of the timing for stopping the supply of the molding material M>

[0050] The timing of stopping the supply of the molding material M is determined as follows. First, based on the maximum amount (full amount) of the molding material M stored in the cylinder 21 and the hopper 24 of the injection device 20, the number of molded products that can be manufactured using the maximum amount of the molding material M is determined, in other words, the number of shots that can be implemented (this number of shots is referred to as the "first number of shots") is determined. Next, the molding material M (so-called buffer material) required to apply back pressure to the molding material M in the cylinder 21 is converted into the number of shots that can be implemented using this amount of molding material M (this number of shots is referred to as the "second number of shots"), and the obtained value is subtracted from the previously determined first number of shots. Then, the time of injection before the number of shots before stopping (= the first number of shots - the second number of shots) compared to the time point when the production target number of shots is implemented and the production of the molded product is completed is set as the time of stopping the supply of the molding material M. In other words, the number of shots before stopping is the number of shots implemented before the production of the molded product is completed and the implementation of injection (molding cycle) is stopped. That is, the number of injections before stopping is the number of implementations before stopping.

[0051] The first number of shots among the number of shots before stopping is calculated, for example, by adding the volume of the hopper 24 to the volume of the cylinder 21 and dividing the obtained volume by the shot capacity. Here, the volume of the cylinder 21 corresponds to the volume of the screw 22 inserted into the cylinder 21, and is determined by the diameter (D) of the screw 22 and the length (L / D) of the screw 22. The volume of the hopper 24 is calculated based on the shape of the hopper 24 and the height of the molding material M stored in the hopper 24 when full. The value obtained by adding the volume of the hopper 24 to the volume of the cylinder 21 is roughly equivalent to the maximum amount of molding material M that the injection device 20 can hold.

[0052] The injection capacity refers to the amount of the molding material M used in one injection. The injection capacity is equivalent to the volume of the molded product and is determined by the internal shape of the mold 31. The injection capacity is also referred to as the molded product capacity. Therefore, the number of injections (i.e., the first injection number) that can be performed in the state where the molding material M is stored to the full amount in the cylinder 21 and the hopper 24 is obtained by dividing the value obtained by adding the volume of the hopper 24 and the volume of the cylinder 21 by the injection capacity.

[0053] In the above description, the first injection number is obtained only based on the volumes of the cylinder 21 and the hopper 24. In contrast, other elements that affect the calculation of the first injection number can also be considered to obtain a more accurate first injection number. As elements that affect the calculation of the first injection number, for example, the metering completion position, the buffer position, the maximum retraction position of the screw, etc. can be cited. The metering completion position refers to the position of the screw 22 when the metering process in the manufacturing process is completed. The metering process is a process of melting the molding material M and transporting it to the front end side of the screw 22 and accumulating it. In this metering process, the screw 22 retracts to a specified position within the cylinder 21. The retracted position is the metering completion position. The buffer position refers to the position when the screw 22 advances maximally within the cylinder 21. The maximum retraction position of the screw refers to the position when the screw 22 retracts maximally within the cylinder 21.

[0054] The second injection number is the amount corresponding to the molding material M required to apply back pressure to the molding material M within the cylinder 21. For example, a fixed value determined based on the volume of the cylinder 21, etc. is set. The number of pre-stop injections is the first injection number - the second injection number. Therefore, after the supply of the molding material M is stopped, at the time point when the injection of the number of pre-stop injections is performed to complete the manufacturing process of the molded product, the second injection number of the molding material M remains in the cylinder 21. The remaining molding material M is the object to be removed.

[0055] <Supply Control of Molding Material M>

[0056] Figure 7 It is a flowchart showing the control of supplying the molding material M to the injection device 20. When manufacturing a molded product, first, the data processing device 200 of the injection molding machine 10 calculates the number of pre-stop injections (recorded as "the number of times N to be performed before stop" in the figure) by referring to the above calculations described in Figure 5 and Figure 6 (S101). Then, through the control of the control device 100, the molding cycle of the molded product is started (S102).

[0057] Next, the control device 100 determines whether it is time to stop the supply of the molding material M. Specifically, the number of shots implemented since the start of the molding cycle until now is set as the shot number C, the number of shots of the production target is set as the shot number T, and the number of shots implemented before the supply of the molding material M is stopped is set as the shot number N, and it is determined whether C=TN. If C=TN is not ("No" in S103), it is determined whether C=TN for each shot. On the other hand, if C=TN ("Yes" in S103), the control device 100 instructs the material supply device 500 to stop supplying the molding material M (S104).

[0058] Next, the control device 100 determines whether C = T. If C = T ("No" in S105), it is determined whether C = T for each injection. On the other hand, if C = T ("Yes" in S105), the control device 100 retreats the injection device 20 from the position during the injection process (S106) and removes the molding material M remaining in the cylinder 21 (S107).

[0059] The above is an explanation of the embodiment of the present invention, but the technical scope of the present invention is not limited to the above embodiment. For example, in the above embodiment, the following structure is set: when manufacturing a molded product, the data processing device 200 calculates the number of injections before stopping, which is the number of injections implemented before the manufacture of the molded product is completed and the injection is stopped. In contrast, for a frequently used mold 31, the number of injections before stopping can be calculated in advance based on the injection capacity of the mold 31 and saved in the storage unit 230 of the data processing device 200, etc. When the mold 31 is used, the saved number of injections before stopping is used to control the supply of the molding material M.

[0060] Furthermore, in the above-described embodiment, the timing to stop the supply of the molding material M is determined based on the number of shots (the first number of shots) that can be performed using the maximum amount (full amount) of the molding material M stored in the cylinder 21 and the hopper 24 of the injection device 20 and the number of shots (the second number of shots) that can be performed using the amount of the molding material M required to apply back pressure in the cylinder 21. In contrast, as information for determining the timing to stop the supply of the molding material M, information other than the number of shots (the number of times the molding cycle is performed) may be used as long as it is information related to the amount of the molding material M required to manufacture the molded product.

[0061] For example, the timing to stop the supply of the molding material M may be determined based on the production quantity of the molded products. In this case, for example, the production quantity of the molded products that can be produced using the full amount of the molding material M is set as the first production quantity, and the production quantity of the molded products that can be produced using the amount of the molding material M required to apply the back pressure in the cylinder 21 is set as the second production quantity. Then, the time when the production quantity of the molded products is the production quantity before the production quantity before stopping (= the first production quantity - the second production quantity) compared to the time point when the production target quantity is reached is considered to be the time to stop the supply of the molding material M.

[0062] Furthermore, the timing to stop the supply of the molding material M may be determined based on the number of rotations of the screw 22 in the injection device 20. In this case, for example, the number of rotations of the screw 22 when a molded product is manufactured using a full amount of the molding material M is set as the first number of rotations, and the number of rotations of the screw 22 when a molded product is manufactured using an amount of the molding material M required to apply back pressure in the cylinder 21 is set as the second number of rotations. Then, the timing to stop the supply of the molding material M is considered to be the time when the number of rotations of the screw 22 becomes the number of rotations before the number of rotations before stopping (= the first number of rotations - the second number of rotations) compared to the number of rotations until the time point when the manufacturing of the molded product is completed. In addition, the number of rotations of the screw 22 is used here, but the rotation time of the screw 22 may be used instead of the number of rotations.

[0063] Furthermore, the timing to stop the supply of the molding material M may be determined based on the driving time of the motor 23 in the injection device 20. In this case, for example, the driving time of the motor 23 when the molded product is manufactured using the full amount of the molding material M is set as the first driving time, and the driving time of the motor 23 when the molded product is manufactured using the amount of the molding material M required to apply the back pressure in the cylinder 21 is set as the second driving time. Then, the timing to stop the supply of the molding material M is considered to be the time when the driving time of the motor 23 is the driving time before the driving time before stopping (= first driving time - second driving time) compared to the driving time until the time point when the manufacturing of the molded product is completed.

[0064] In addition, the timing to stop the supply of the molding material M may be determined by using the amount of movement of the injection device 20 determined by the parameters such as the molding time and the metering time, which can determine the number of molded products that can be manufactured using the full amount of the molding material M. For example, the amount of movement of the injection device 20 when the molded product is manufactured using the full amount of the molding material M and the amount of movement of the injection device 20 when the molded product is manufactured using the amount of the molding material M required to apply back pressure in the cylinder 21 can be used to determine the amount of movement of the injection device 20 to stop the supply of the molding material M relative to the time point when the molded product is manufactured. In addition, various changes or structural substitutions that do not depart from the scope of the technical idea of ​​the present invention are also included in the present invention.

Claims

1. An injection molding machine, characterized in that: have: An injection device that injects molding material into a mold of a molded product; and a control device for controlling the supply of molding material to the injection device, The control device sets a pre-stop action amount representing the amount of action performed before stopping the action of the injection device for manufacturing the molded product based on a parameter that determines the number of molded products that can be manufactured using the molding material retained in the injection device, and stops supplying molding material to the injection device at a time point traced back to the pre-stop action amount from the time when the action of the injection device stops.

2. The injection molding machine according to claim 1, characterized in that The operation amount before stopping is an operation amount obtained by subtracting a predetermined operation amount of the injection device from an operation amount of the injection device for manufacturing a quantity of molded products that can be manufactured using the molding material held in the injection device.

3. The injection molding machine according to claim 2, characterized in that The predetermined operation amount of the injection device is a value obtained by converting the amount of molding material required to apply back pressure to the molding material in the injection device into the operation amount of the injection device.

4. The injection molding machine according to any one of claims 1 to 3, characterized in that The injection device comprises: a cylinder body filled with a molding material; and A hopper is used to supply molding material to the cylinder. The control device calculates an operation amount of the injection device for manufacturing a number of molded products that can be manufactured using the molding material held in the injection device, based on the volumes of the molding material in the cylinder and the hopper and the volume of the mold.

5. An injection molding machine, characterized in that: have: An injection device that injects molding material into a mold of a molded product; and a control device for controlling the supply of molding material to the injection device, The control device sets the number of times the molding cycle is implemented before stopping the implementation of the molding cycle, i.e., the number of implementations before stopping, based on the number of implementations of the molding cycle of the molded product that can be implemented using the molding material maintained in the injection device, and stops supplying the molding material to the injection device at the time point of the number of implementations before stopping, tracing back from the time when the molding cycle is stopped.

6. A control device for controlling an injection device for injecting a molding material into a mold of a molded product to supply a molding material, the control device comprising: a setting means for setting a pre-stop operation amount representing the amount of operation of the injection device to be performed before stopping the operation of the injection device for manufacturing the molded product, based on a parameter that determines the number of molded products that can be manufactured using the molding material held in the injection device; and The stopping mechanism stops supplying the molding material to the injection device at a time point traced back by the amount of movement before the stop from when the operation of the injection device stops.

7. A program that controls an injection device that injects a molding material into a mold of a molded product to supply a molding material and that can be executed by a computer, characterized in that: The following functions are implemented in the computer: setting a pre-stop operation amount representing the amount of operation of the injection device to be performed before stopping the operation of the injection device for producing the molded product, based on a parameter that determines the number of molded products that can be produced using the molding material held in the injection device; and Supply of the molding material to the injection device is stopped at a time point traced back from the time when the operation of the injection device is stopped by the amount of operation before the stop.

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