JP6815892B2 - Injection molding machine - Google Patents

Description

The present invention relates to an injection molding machine.

The injection molding machine described in Patent Document 1 converts the unit for setting condition items, which differs for each model depending on the screw diameter, into a unit common to each model regardless of the screw diameter. Have means. For example, the unit conversion means converts the unit mm of the injection position into the unit cc of the injection amount. Further, the unit conversion means converts the unit of the injection speed from mm / sec to cc / sec. It is possible to save the labor of the operator manually resetting the molding conditions.

Japanese Patent No. 3701907

When the structure of the injection molding machine is changed, it is necessary to change the setting of the injection molding machine because the frictional resistance, inertia, control response, etc. are different, but the setting of the injection molding machine cannot be changed for the convenience of the user. was there.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an injection molding machine that ensures compatibility of settings of the injection molding machine when the structure of the injection molding machine is different.

In order to solve the above problems, according to one aspect of the present invention,
A control device for generating an operation amount of a controlled object portion based on a set value of a controlled amount indicating a molding condition and a detected value of the controlled amount is provided.
The controlled amount and the manipulated amount have a different relationship depending on the difference in the structure of the injection molding machine.
When the control device uses the set value when the structure is a different structure from the current structure to generate the operation amount when the structure is the current structure, the control of the different structure the relationship between the amount and the operation amount, the said detection value is corrected based on the relationship and the difference of said controlled variable and the manipulated variable of the current structure, the said set value and the detected value of the corrected An injection molding machine is provided that produces the operation amount based on the above.

According to one aspect of the present invention, there is provided an injection molding machine that ensures compatibility of settings of the injection molding machine when the structure of the injection molding machine is different.

It is a figure which shows the state at the time of completion of the mold opening of the injection molding machine by one Embodiment. It is a figure which shows the state at the time of mold clamping of the injection molding machine by one Embodiment. It is a figure which shows the operation screen of the injection molding machine by one Embodiment. It is a figure which shows the relationship between the back pressure of a screw, the pressure of a molding material, and frictional resistance in the weighing process by one Embodiment. It is a figure which shows the relationship between the heating amount of a cylinder by a heater, the heat transfer amount from a cylinder to a molding material, and the heat amount which moves from a cylinder to a cooler in injection molding by one Embodiment.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings, but in each drawing, the same or corresponding configurations will be referred to with the same or corresponding reference numerals and description thereof will be omitted.

FIG. 1 is a diagram showing a state at the time of completion of mold opening of the injection molding machine according to one embodiment. FIG. 2 is a diagram showing a state at the time of mold clamping of the injection molding machine according to one embodiment. As shown in FIGS. 1 and 2, the injection molding machine 2 includes a frame Fr, a mold clamping device 10, an injection device 40, an ejector device 50, a control device 90, an input device 95, and an output device 96. Has.

First, the mold clamping device 10 and the ejector device 50 will be described. In the description of the mold clamping device 10 and the like, the moving direction of the movable platen 13 when the mold is closed (right direction in FIGS. 1 and 2) is set to the front, and the moving direction of the movable platen 13 when the mold is opened (in FIGS. 1 and 2). The left direction) will be described as the rear.

The mold clamping device 10 closes, clamps, and opens the mold of the mold apparatus 30. The mold clamping device 10 includes a fixed platen 12, a movable platen 13, a support platen 15, a tie bar 16, a toggle mechanism 20, a mold clamping motor 21, and a motion conversion mechanism 25.

The fixed platen 12 is fixed to the frame Fr. The fixed mold 32 is attached to the surface of the fixed platen 12 facing the movable platen 13.

The movable platen 13 is movable along a guide (for example, a guide rail) 17 laid on the frame Fr, and is movable back and forth with respect to the fixed platen 12. The movable mold 33 is attached to the surface of the movable platen 13 facing the fixed platen 12.

By advancing and retreating the movable platen 13 with respect to the fixed platen 12, mold closing, mold clamping, and mold opening are performed. The mold device 30 is composed of the fixed mold 32 and the movable mold 33.

The support platen 15 is connected to the fixed platen 12 at intervals, and is movably placed on the frame Fr in the mold opening / closing direction. The support platen 15 may be movable along a guide laid on the frame Fr. The guide of the support platen 15 may be the same as that of the guide 17 of the movable platen 13.

In the present embodiment, the fixed platen 12 is fixed to the frame Fr and the support platen 15 is movable in the mold opening / closing direction with respect to the frame Fr, but the support platen 15 is fixed to the frame Fr and the fixed platen is fixed. 12 may be movable in the mold opening / closing direction with respect to the frame Fr.

The tie bar 16 connects the fixed platen 12 and the support platen 15 at intervals. A plurality of tie bars 16 may be used. Each tie bar 16 is parallel to the mold opening / closing direction and extends according to the mold clamping force. At least one tie bar 16 is provided with a mold clamping force detector 18. The mold clamping force detector 18 detects the mold clamping force by detecting the strain of the tie bar 16, and sends a signal indicating the detection result to the control device 90.

The mold clamping force detector 18 is not limited to the strain gauge type, but may be a piezoelectric type, a capacitive type, a hydraulic type, an electromagnetic type, or the like, and the mounting position thereof is not limited to the tie bar 16.

The toggle mechanism 20 moves the movable platen 13 with respect to the fixed platen 12. The toggle mechanism 20 is arranged between the movable platen 13 and the support platen 15. The toggle mechanism 20 is composed of a crosshead 20a, a pair of links, and the like. Each link group has a plurality of links 20b and 20c that are flexibly connected by a pin or the like. One link 20b is swingably attached to the movable platen 13, and the other link 20c is swingably attached to the support platen 15. When the crosshead 20a is moved forward and backward, the plurality of links 20b and 20c bend and stretch, and the movable platen 13 moves forward and backward with respect to the support platen 15.

The mold clamping motor 21 is attached to the support platen 15 and operates the toggle mechanism 20. The mold clamping motor 21 bends and stretches the links 20b and 20c by moving the crosshead 20a back and forth, and moves the movable platen 13 back and forth.

The motion conversion mechanism 25 converts the rotational motion of the mold clamping motor 21 into a linear motion and transmits it to the crosshead 20a. The motion conversion mechanism 25 is composed of, for example, a ball screw mechanism.

The operation of the mold clamping device 10 is controlled by the control device 90. The control device 90 controls a mold closing process, a mold clamping process, a mold opening process, and the like.

In the mold closing step, the mold clamping motor 21 is driven to advance the crosshead 20a at a set speed to advance the movable platen 13 and bring the movable mold 33 into contact with the fixed mold 32. The position and speed of the crosshead 20a are detected by, for example, the encoder 21a of the mold clamping motor 21. A signal indicating the detection result is sent to the control device 90.

In the mold clamping step, the mold clamping force 21 is further driven to further advance the crosshead 20a to the set position to generate a mold clamping force. At the time of mold clamping, a cavity space 34 is formed between the movable mold 33 and the fixed mold 32, and the cavity space 34 is filled with a liquid molding material. A molded product is obtained by solidifying the filled molding material. The number of cavity spaces 34 may be plural, in which case a plurality of molded articles can be obtained at the same time.

In the mold opening step, the mold clamping motor 21 is driven to retract the crosshead 20a at a set speed, whereby the movable platen 13 is retracted and the movable mold 33 is separated from the fixed mold 32.

The mold clamping device 10 of the present embodiment has a mold clamping motor 21 as a drive source, but may have a hydraulic cylinder instead of the mold clamping motor 21. Further, the mold clamping device 10 may have a linear motor for opening and closing the mold and an electromagnet for mold clamping.

Further, the mold clamping device 10 of the present embodiment is a horizontal mold whose mold opening / closing direction is horizontal, but may be a vertical mold whose mold opening / closing direction is vertical.

The ejector device 50 projects a molded product from the mold device 30. The ejector device 50 includes an ejector motor 51, a motion conversion mechanism 52, and an ejector rod 53.

The ejector motor 51 is attached to the movable platen 13. The ejector motor 51 is directly connected to the motion conversion mechanism 52, but may be connected to the motion conversion mechanism 52 via a belt, a pulley, or the like.

The motion conversion mechanism 52 converts the rotational motion of the ejector motor 51 into a linear motion of the ejector rod 53. The motion conversion mechanism 52 is composed of, for example, a ball screw mechanism or the like.

The ejector rod 53 is free to move forward and backward in the through hole of the movable platen 13. The front end portion of the ejector rod 53 comes into contact with a movable member 35 that is movably arranged in the movable mold 33. The ejector rod 53 may be connected to the movable member 35.

The operation of the ejector device 50 is controlled by the control device 90. The control device 90 controls the projecting process and the like.

In the projecting step, the ejector motor 51 is driven to advance the ejector rod 53, thereby advancing the movable member 35 and projecting the molded product. After that, the ejector motor 51 is driven to retract the ejector rod 53, and the movable member 35 is retracted to the original position. The position and speed of the ejector rod 53 are detected by, for example, the encoder 51a of the ejector motor 51. A signal indicating the detection result is sent to the control device 90.

Next, the injection device 40 will be described. In the description of the injection device 40, unlike the description of the mold clamping device 10, the moving direction of the screw 43 during filling (left direction in FIGS. 1 and 2) is set to the front, and the moving direction of the screw 43 during weighing (FIGS. 1 and 2). The right direction in FIG. 2) will be described as the rear.

The injection device 40 is installed on a slide base Sb that can move forward and backward with respect to the frame Fr, and is adjustable with respect to the mold device 30. The injection device 40 is touched by the mold device 30 to fill the mold device 30 with a molding material.

The injection device 40 includes, for example, a cylinder 41, a nozzle 42, a screw 43, a cooler 44, a measuring motor 45, an injection motor 46, a pressure detector 47, a heater 48, and a temperature detector 49.

The cylinder 41 heats the molding material supplied internally from the supply port 41a. The supply port 41a is formed at the rear portion of the cylinder 41. A cooler 44 such as a water-cooled cylinder is provided on the outer periphery of the rear portion of the cylinder 41. A heater 48 such as a band heater and a temperature detector 49 are provided on the outer periphery of the cylinder 41 in front of the cooler 44.

The cylinder 41 is divided into a plurality of zones in the axial direction of the cylinder 41 (left-right direction in FIGS. 1 and 2). A heater 48 and a temperature detector 49 are provided in each zone. The control device 90 controls the heater 48 so that the measured temperature of the temperature detector 49 becomes the set temperature for each zone.

The nozzle 42 is provided at the front end of the cylinder 41 and is pressed against the mold device 30. A heater 48 and a temperature detector 49 are provided on the outer periphery of the nozzle 42. The control device 90 controls the heater 48 so that the measured temperature of the nozzle 42 becomes the set temperature.

The screw 43 is rotatably and movably arranged in the cylinder 41.

The metering motor 45 rotates the screw 43 to feed the molding material forward along the spiral groove of the screw 43. The molding material is gradually melted by the heat from the cylinder 41 while being fed forward. As the liquid molding material is fed to the front of the screw 43 and accumulated in the front of the cylinder 41, the screw 43 is retracted.

The injection motor 46 advances and retreats the screw 43. By advancing the screw 43, the injection motor 46 ejects the liquid molding material accumulated in front of the screw 43 from the cylinder 41 and fills the mold device 30. After that, the injection motor 46 pushes the screw 43 forward to apply pressure to the molding material in the mold apparatus 30. The shortage of molding material can be replenished. Between the injection motor 46 and the screw 43, a motion conversion mechanism for converting the rotational motion of the injection motor 46 into the linear motion of the screw 43 is provided. This motion conversion mechanism is composed of a ball screw mechanism or the like.

The pressure detector 47 is arranged between the injection motor 46 and the screw 43, for example, and detects the pressure received by the screw 43 from the molding material, the back pressure on the screw 43, and the like. The pressure that the screw 43 receives from the molding material corresponds to the pressure that acts on the molding material from the screw 43. The pressure detector 47 sends a signal indicating the detection result to the control device 90.

The operation of the injection device 40 is controlled by the control device 90. The control device 90 controls a filling process, a pressure holding process, a measuring process, and the like.

In the filling step, the injection motor 46 is driven to advance the screw 43 at a set speed, and the liquid molding material accumulated in front of the screw 43 is filled in the mold device 30. The position and speed of the screw 43 are detected by, for example, the encoder 46a of the injection motor 46. A signal indicating the detection result is sent to the control device 90. When the position of the screw 43 reaches the set position, switching from the filling process to the pressure holding process (so-called V / P switching) is performed. The set speed of the screw 43 may be changed according to the position and time of the screw 43.

After the position of the screw 43 reaches the set position in the filling step, the screw 43 may be temporarily stopped at the set position, and then V / P switching may be performed. Immediately before the V / P switching, the screw 43 may be moved forward or backward at a slow speed instead of stopping the screw 43.

In the pressure holding step, the injection motor 46 is driven to push the screw 43 forward at a set pressure to apply pressure to the molding material in the mold apparatus 30. The shortage of molding material can be replenished. The pressure of the molding material is detected by, for example, the pressure detector 47. A signal indicating the detection result is sent to the control device 90.

In the pressure holding step, the molding material in the mold apparatus 30 is gradually cooled, and when the pressure holding step is completed, the inlet of the cavity space 34 is closed with the solidified molding material. This state is called a gate seal, and backflow of the molding material from the cavity space 34 is prevented. After the pressure holding step, the cooling step is started. In the cooling step, the molding material in the cavity space 34 is solidified. A weighing step may be performed during the cooling step to shorten the molding cycle.

In the weighing step, the weighing motor 45 is driven to rotate the screw 43 at a set rotation speed, and the molding material is fed forward along the spiral groove of the screw 43. Along with this, the molding material is gradually melted. As the liquid molding material is fed to the front of the screw 43 and accumulated in the front of the cylinder 41, the screw 43 is retracted. The rotation speed of the screw 43 is detected by, for example, the encoder 45a of the measuring motor 45. A signal indicating the detection result is sent to the control device 90.

In the weighing step, the injection motor 46 may be driven to apply a set back pressure to the screw 43 in order to limit the sudden retreat of the screw 43. The back pressure on the screw 43 is detected, for example, by the pressure detector 47. A signal indicating the detection result is sent to the control device 90. When the screw 43 retracts to the set position and a predetermined amount of molding material is accumulated in front of the screw 43, the weighing process ends.

The injection device 40 of the present embodiment is an in-line screw type, but may be a pre-plastic type. The pre-plastic injection device supplies the molded material melted in the plasticizing cylinder to the injection cylinder, and injects the molding material from the injection cylinder into the mold device. A screw is rotatably or rotatably arranged in the plasticized cylinder and can be moved forward and backward, and a plunger is rotatably arranged in the injection cylinder.

As shown in FIGS. 1 and 2, the control device 90 includes a CPU (Central Processing Unit) 91, a storage medium 92 such as a memory, an input interface 93, and an output interface 94. The control device 90 performs various controls by causing the CPU 91 to execute the program stored in the storage medium 92. Further, the control device 90 receives a signal from the outside at the input interface 93 and transmits the signal to the outside at the output interface 94.

The input device 95 accepts the user's input operation and transmits an operation signal corresponding to the user's input operation to the control device 90. As the input device 95, for example, a touch panel is used. The touch panel also serves as the output device 96 described later.

The output device 96 displays an operation screen corresponding to the input operation of the input device 95 under the control of the control device 90. Multiple operation screens are prepared and can be switched and displayed or displayed in an overlapping manner.

The user sets the mold clamping device 10, the injection device 40, the ejector device, and the like by operating the input device 95 while looking at the operation screen displayed on the output device 96. The settings are stored in the storage medium 92 and read out as needed.

The control device 90 generates an operation amount of the controlled amount based on the set value of the controlled amount indicating the molding condition and the detected value of the controlled amount. As the control target unit, for example, an electric power device is used, and a motor, a heater, or the like is used.

The control device 90 may generate an operation amount of the controlled amount so that the difference between the set value of the controlled amount and the detected value of the controlled amount becomes zero. The control method of the present embodiment is feedback control, but feedforward control may also be used.

As the control amount, for example, at least one physical quantity selected from force, pressure, torque, temperature, current, moving distance (for example, rotational moving distance, linear moving distance), and load time is used alone or in combination. The combination may be any of sum, difference, product, and quotient, and may be a plurality of these. Examples of the combination include the product of the force and the moving distance, the product of the force and the load time, the quotient of the moving distance and the load time (that is, the speed), and the like.

By the way, the injection molding machine 2 has a different structure for each model. Further, even if the injection molding machine 2 is the same model, it may be equipped with a substitute part due to the discontinuation of production of the replacement part or the like, and may have a different structure. The controlled amount and the operated amount have a different relationship depending on the difference in the structure of the injection molding machine 2. The relationship between the controlled variable and the manipulated variable is represented by, for example, a transfer function.

For example, in the weighing process, the relationship between the back pressure of the screw 43, which is a controlled amount (more specifically, the pressure of the molding material controlled by the back pressure of the screw 43), and the supply current of the injection motor 46, which is an operating amount, is , Because it is affected by the frictional resistance of peripheral devices, it differs depending on the difference in the structure of peripheral devices. For example, when the supply current of the injection motor 46 is the same and the frictional resistance of the peripheral device is reduced, the pressure of the molding material is increased. Examples of cases where the frictional resistance of peripheral devices is reduced include cases where a sealing member for preventing leakage of lubricant is not required. As the frictional resistance of the sealing member disappears, the overall frictional resistance becomes smaller.

Similarly, in the pressure holding process, the relationship between the pressure of the molding material, which is the control amount, and the supply current of the injection motor 46, which is the operation amount, is affected by the frictional resistance of the peripheral equipment, so that there is a difference in the structure of the peripheral equipment. Depends on.

Further, the relationship between the controlled amount of the temperature of the cylinder 41 (more specifically, the temperature of the molding material controlled by the temperature of the cylinder 41) and the operation amount of the supply current of the heater 48 is the heat of the cylinder 41 or the like. Because it is affected by the movement of the cylinder 41, it differs depending on the difference in the structure of the cylinder 41 and the like. For example, when the supply current of the heater 48 is the same, the temperature of the molding material becomes high when the transfer of heat from the heater 48 to the cooler 44 is restricted. Examples of cases where heat transfer is restricted include the case where a heat insulating ring 41b is added to the cylinder 41 between the heater 48 and the cooler 44. The heat transfer can be restricted in the middle of the cylinder 41.

Therefore, the control device 90 uses the set value when the structure of the injection molding machine is different from the current structure to generate the operation amount when the structure of the injection molding machine is the current structure. The detected value of the control amount is corrected based on the structural difference between the different structure and the current structure. The correction amount of the detected value is determined in advance by a test or the like, and the one stored in the storage medium 92 is read out and used. For example, when the control amount is the back pressure of the screw 43 in the weighing process, the correction amount is adjusted so that the pressure of the molding material obtained by removing the frictional resistance from the pressure detected by the pressure detector 47 is the same regardless of the structural difference. Is decided. Similarly, when the control amount is the pressure of the molding material in the pressure holding step, the pressure of the molding material obtained by removing the frictional resistance from the pressure detected by the pressure detector 47 is corrected so as to be the same regardless of the structural difference. The amount is decided. When the control amount is the temperature of the cylinder 41, the correction amount is determined so that the temperature of the molding material inside the cylinder 41 is the same regardless of the structural difference. Whether or not the temperature of the molding material inside the cylinder 41 is the same can be checked by checking whether or not the torque of the measuring motor 45 in the measuring process is the same. This is because if the torque of the measuring motor 45 is the same, the viscosity of the molding material inside the cylinder 41 and thus the temperature are the same.

The control device 90 generates an operation amount based on the corrected detection value and the set value. Therefore, when the structures of the injection molding machines 2, 2A and 2B are different, the compatibility of the settings of the injection molding machines 2, 2A and 2B can be ensured. For example, when the same mold device 30 is mounted on each of the injection molding machines 2, 2A and 2B, it is not necessary to change the setting for each of the injection molding machines 2, 2A and 2B, and it can be adjusted to the convenience of the user. .. Further, even if the structure of the injection molding machine 2 is changed due to the whole replacement (model change) of the injection molding machine 2 or the replacement of a part of the injection molding machine 2, the compatibility of the settings can be ensured. Yes, the old settings before replacement can be used as they are.

The control device 90 stores the correction amount of the detection value for each structure candidate of the injection molding machine 2 in advance, and when one candidate is selected from the plurality of structure candidates, the correction amount corresponding to the selected structure is used. The detected value may be corrected. One candidate may be specified by a combination of a plurality of elements. If the selected structure is the current structure instead of another structure, the correction amount is naturally zero.

The control device 90 may be connected to another injection molding machine 2A or 2B via a network 4 or the like. The network 4 may be wired or wireless. The injection molding machine 2A has an A structure different from the current structure of the injection molding machine 2, and the injection molding machine 2B has a B structure different from the current structure of the injection molding machine 2. The A structure and the B structure are different structures. The control device 90 can acquire a combination of each structure and a set value from the injection molding machines 2A and 2B. A storage medium such as a memory card may be used for the acquisition, or the network 4 may not be used.

The control device 90 stores the structure and the set value in association with each other in the storage medium 92. The control device 90 can automatically select a structure associated with the currently set set value based on the currently set set value and the information stored in the storage medium 92. It can be determined whether the currently set value has the current structure or another structure. The trouble of selecting the structure by the user can be omitted, and the erroneous selection by the user can be prevented.

The control device 90 uses a set value when the structure of the injection molding machine is different from the current structure to generate a control amount when the structure of the injection molding machine is the current structure. The detected value may be corrected so that a predetermined physical quantity different from the above is constant. For example, when the controlled amount is the temperature of the cylinder 41, the control device 90 corrects the detected value so that the torque of the measuring motor 45 in the measuring process is the same. This is because the torque of the measuring motor 45 represents the viscosity of the molding material inside the cylinder 41 and thus the temperature.

FIG. 3 is a diagram showing an operation screen of the injection molding machine according to the embodiment. This operation screen 100 is used for correcting the detected value. The operation screen 100 includes, for example, a control amount input field 101, a structure input field 102, and an execution / cancellation selection field 103.

The control amount input field 101 is a field in which the user inputs a control amount indicating molding conditions. When the user touches the control amount input field 101, control amount candidates may be popped up. The user can select the control amount from the candidates.

The structure input field 102 is a field in which the user inputs a structure corresponding to the set value of the control amount input in the control amount input field 101. When the user touches the structure input field 102, structure candidates may be popped up. The user can select the structure from the candidates.

The execution / cancellation selection field 103 is a field in which the user selects execution or cancellation of correction of the detection value of the control amount input in the control amount input field 101. Each time the user touches the control amount input field 101, the display may be switched between "ON" which means execution and "OFF" which means cancellation.

The control device 90 corrects the detected value of the control amount according to the input operation of the user on the operation screen 100. When the type of control amount and the type of structure are predetermined, the control amount input field 101 and the structure input field 102 may be omitted, but may remain.

The control device 90 may store the authority information regarding whether or not to permit the operation of the operation screen 100 in the storage medium 92 in advance for each identification information such as the user's number and name. Whether the control device 90 acquires the identification information of the user who operates the operation screen 100 with a reader or the like, and permits the operation of the operation screen 100 based on the acquired identification information and the information stored in the storage medium 92 in advance. Decide whether or not. Only an authorized user can operate the operation screen 100, and an operation of the operation screen 100 by an unauthorized user can be prohibited. As the reader, an input device 95, a one-dimensional code reader, a two-dimensional code reader, or the like is used.

FIG. 4 is a diagram showing the relationship between the back pressure of the screw, the pressure of the molding material, and the frictional resistance in the weighing process according to the embodiment. FIG. 4A is a diagram showing the relationship between the back pressure of the screw, the pressure of the molding material, and the frictional resistance in the weighing process of the injection molding machine of the first structure. FIG. 4B shows the back pressure of the screw, the pressure of the molding material, and the frictional resistance in the weighing process in which the detection value correction is off (released state) in the injection molding machine having the second structure different from the first structure. It is a relationship diagram with. FIG. 4C is a diagram showing the relationship between the back pressure of the screw, the pressure of the molding material, and the frictional resistance in the weighing process in which the detection value correction is on (implemented state) in the injection molding machine having the second structure. .. In FIG. 4, the first structure is when there is a seal member for preventing the leakage of the lubricant, that is, when the frictional resistance of the drive system of the screw 43 is large, and when the seal member is not provided, that is, the frictional resistance of the drive system of the screw 43. The case where is small is called the second structure.

The control device 90 shown in FIGS. 4 (a) to 4 (c) generates an operation amount that generates an operation amount of the controlled target portion based on a set value of the control amount indicating the molding condition and the detected value of the control amount. It has a part 97. Further, the control device 90 shown in FIGS. 4 (b) to 4 (c) has a detection value correction unit 98 that corrects the detection value of the control amount based on the structural difference between the second structure and the first structure.

It should be noted that each functional block of the control device 90 shown in FIG. 4 is conceptual and does not necessarily have to be physically configured as shown in the figure. All or part of each functional block can be functionally or physically distributed / integrated in any unit. Each processing function performed in each function block may be realized by a program executed by the CPU, or as hardware by wired logic, in whole or in any part thereof. The same applies to each functional block of the control device shown in FIG.

In FIG. 4A, the structure of the injection device 40 is the first structure. At this time, the operation amount generation unit 97 generates the supply current value of the injection motor 46, which is the operation amount, based on the set value BP0 of the back pressure of the screw 43, which is the control amount, and the detection value BP1. The operation amount generation unit 97 generates the supply current value of the injection motor 46 so that the deviation between the set value BP0 and the detected value BP1 becomes zero. The back pressure detection value BP1 of the screw 43 is detected by the pressure detector 47.

In FIG. 4B, the structure of the injection device 40 is a second structure different from the first structure, but cancellation (off) of the detection value correction is selected in the implementation / cancellation selection field 103 shown in FIG. Therefore, the detection value correction unit 98 does not function, and the detection value BP2 of the back pressure of the screw 43 is not corrected. Therefore, the manipulated variable generation unit 97 generates the supply current value of the injection motor 46 based on the set value BP0 and the detected value BP2, as in the case where the structure of the injection device 40 is the first structure.

By the way, in the measuring step, the pressure MP of the molding material is represented by the difference (BP-FR) between the detected value BP of the back pressure of the screw 43 and the frictional resistance FR. In the weighing process, the pressure MP of the molding material is required to be within the permissible range.

Here, the frictional resistance FR related to the pressure MP of the molding material is determined by the structure of the injection device 40 and the like. When the detected value BP of the back pressure of the screw 43 is the same, the larger the frictional resistance FR, the smaller the pressure MP of the molding material.

Further, the detected value BP of the back pressure of the screw 43, which is related to the pressure MP of the molding material, is determined by the supply current value of the injection motor 46 or the like. When the frictional resistance FR is the same, the larger the supply current value of the injection motor 46, the larger the detected value BP of the back pressure of the screw 43 and the larger the pressure MP of the molding material.

When the detection value correction unit 98 does not function, the supply current value of the injection motor 46 is generated in the same manner as when the structure of the injection device 40 is the first structure. Therefore, the back pressure detection value BP2 of the screw 43 is the same as the detection value BP1 when the structure of the injection device 40 is the first structure. On the other hand, the frictional resistance FR2 of the second structure is smaller than the frictional resistance FR1 of the first structure. As a result, the pressure MP2 of the molding material of the second structure becomes larger than the pressure MP1 of the molding material of the first structure.

On the other hand, in FIG. 4 (c), the structure of the injection device 40 is the second structure as in FIG. 4 (b), but unlike FIG. 4 (b), it is detected in the implementation / cancellation selection column 103 shown in FIG. Since the value correction execution (on) is selected, the detected value correction unit 98 functions.

The detection value correction unit 98 corrects the detection value BP2 of the back pressure of the screw 43 based on the structural difference between the second structure and the first structure. For example, when the frictional resistance FR becomes smaller due to the structure of the injection device changing from the first structure to the second structure, the detection value correction unit 98 largely corrects the detection value BP2 of the back pressure of the screw 43. Since the detected value after correction is large, the manipulated variable generation unit 97 reduces the supply current value of the injection motor 46 so as to eliminate the deviation from the set value. As a result, the actual detected value BP2'of the back pressure of the screw 43 becomes smaller, and the pressure MP2'of the molding material when the structure of the injection device 40 is the second structure is the structure of the injection device 40 as the first structure. It becomes equivalent to the pressure MP1 of the molding material in the case. The detection value correction unit 98 is a pressure detector based on the structural difference between the second structure and the first structure so that the pressure MP2'of the molding material of the second structure becomes equal to the pressure MP1 of the molding material of the first structure. The detected value BP2 of 47 is corrected. Therefore, the same pressure setting value can be used in the weighing process between the injection molding machine having the first structure and the injection molding machine having the second structure, and compatibility of the settings can be ensured.

The back pressure detection value BP2'of the screw 43 shown in FIG. 4 (c) is smaller than the back pressure detection value BP2 of the screw 43 shown in FIG. 4 (b), which is shown in FIG. 4 (c). The frictional resistance FR2'is smaller than the frictional resistance FR2 shown in FIG. 4 (b). The ratio of FR2 to BP2 and the ratio of FR2'to BP2'are equal. The detection value correction unit 98 changes the detection value of the back pressure of the screw 43 (BP2'and BP2 so that the pressure MP2'of the molding material of the second structure becomes equal to the pressure MP1 of the molding material of the first structure. The back pressure detection value BP2 of the screw 43 may be corrected based on the change in frictional resistance (difference between FR2'and FR2) caused by the difference).

Since the control in the pressure holding process is the same as the control in the weighing process, the description will be simplified. In the pressure holding step, the detection value correction unit 98 makes the pressure MP2'of the molding material of the second structure equal to the pressure MP1 of the molding material of the first structure based on the structural difference between the second structure and the first structure. In addition, the detection value BP2 of the pressure detector 47 is corrected. As a result, the same pressure setting value can be used in the pressure holding step between the injection molding machine having the first structure and the injection molding machine having the second structure, and compatibility of the settings can be ensured. In the pressure holding step, the detection value correction unit 98 of the pressure detector 47 so that the pressure MP2'of the molding material of the second structure becomes equal to the pressure MP1 of the molding material of the first structure, as in the measuring step. The detected value BP2 of the pressure detector 47 may be corrected based on the change in frictional resistance (difference between FR2'and FR2) caused by the change in the detected value (difference between BP2'and BP2).

FIG. 5 is a diagram showing the relationship between the heating amount of the cylinder by the heater, the heat transfer amount from the cylinder to the molding material, and the heat amount transferred from the cylinder to the cooler in the injection molding according to the embodiment. FIG. 5A shows the relationship between the amount of heat of the cylinder by the heater, the amount of heat transfer from the cylinder to the molding material, and the amount of heat transferred from the cylinder to the cooler in the injection molding of the injection molding machine of the first structure. It is a figure which shows. FIG. 5B shows the amount of heat of the cylinder by the heater and the amount of heat from the cylinder to the molding material in the injection molding in which the detection value correction is off (released state) in the injection molding machine having the second structure different from the first structure. It is a figure which shows the relationship between the amount of heat transfer of, and the amount of heat which moves from a cylinder to a cooler. FIG. 5C shows the amount of heat of the cylinder by the heater, the amount of heat transfer from the cylinder to the molding material, and the cylinder in the injection molding in which the detection value correction is on (implemented state) in the injection molding machine of the second structure. It is a figure which shows the relationship with the amount of heat transferred from to a cooler. In FIG. 5, the first structure is when the heat insulating ring 41b is not provided, that is, the amount of heat transferred from the cylinder 41 to the cooler 44 is large, and when the heat insulating ring 41b is present, that is, the amount of heat transferred from the cylinder 41 to the cooler 44 is small. The case is called the second structure.

The control device 90 shown in FIGS. 5 (a) to 5 (c) generates an operation amount that generates an operation amount of the controlled object portion based on a set value of the control amount indicating the molding condition and the detected value of the control amount. It has a part 97. Further, the control device 90 shown in FIGS. 5 (b) to 5 (c) has a detection value correction unit 98 that corrects the detection value of the control amount based on the structural difference between the second structure and the first structure.

In FIG. 5A, the structure of the injection device 40 is the first structure. At this time, the operation amount generation unit 97 generates the supply current value of the heater 48, which is the operation amount, based on the set value T0 of the temperature of the cylinder 41, which is the control amount, and the detection value T1 thereof. The operation amount generation unit 97 generates the supply current value of the heater 48 so that the deviation between the set value T0 and the detected value T1 becomes zero. The supply current value may be expressed by the ratio of the on-time for supplying the current to the heater 48 and the off-time for not supplying the current to the heater 48 (that is, the ratio of the on-time to the unit time).

In FIG. 5B, the structure of the injection device 40 is a second structure different from the first structure, but cancellation (off) of the detection value correction is selected in the implementation / cancellation selection field 103 shown in FIG. Therefore, the detection value correction unit 98 does not function, and the detection value T2 of the temperature of the cylinder 41 is not corrected. Therefore, the operation amount generation unit 97 generates the supply current value of the heater 48 based on the set value T0 and the detection value T2, as in the case where the structure of the injection device 40 is the first structure.

By the way, in injection molding, the temperature of the molding material inside the cylinder 41 (hereinafter, also simply referred to as “the temperature of the molding material”) is the amount of heat transferred from the cylinder 41 to the molding material (hereinafter, “the heating amount of the molding material MH”). It is also called.). The heating amount MH of the molding material includes the heating amount of the cylinder 41 by the heater 48 (hereinafter, also simply referred to as “heating amount SH of the cylinder 41”) and the heat amount transferred from the cylinder 41 to the cooler 44 (hereinafter, simply “”. It is also referred to as "transfer heat amount EH") and is represented by the difference (SH-EH). In injection molding, the temperature of the molding material is required to be within an acceptable range.

Here, the heat transfer amount EH related to the temperature of the molding material is determined by the structure of the injection device 40 and the like. When the heating amount SH of the cylinder 41 is the same, the smaller the transferred heat amount EH, the larger the heating amount MH of the molding material and the higher the temperature of the molding material.

Further, the heating amount SH of the cylinder 41, which is related to the temperature of the molding material, is determined by the supply current value of the heater 48 or the like. When the transfer heat amount EH is the same, the larger the supply current value of the heater 48, the larger the heating amount SH of the cylinder 41 and the higher the temperature of the molding material.

When the detection value correction unit 98 does not function, the supply current value of the heater 48 is generated in the same manner as when the structure of the injection device 40 is the first structure. Therefore, the heating amount SH2 of the cylinder 41 has a value equivalent to the heating amount SH1 when the structure of the injection device 40 is the first structure. On the other hand, the heat transfer amount EH2 of the second structure is smaller than the heat transfer amount EH1 of the first structure. As a result, the heating amount MH2 of the molding material of the second structure is larger than the heating amount MH1 of the molding material of the first structure, and the temperature of the molding material of the second structure is higher than the temperature of the molding material of the first structure.

On the other hand, in FIG. 5 (c), the structure of the injection device 40 is the second structure as in FIG. 5 (b), but unlike FIG. 5 (b), it is detected in the implementation / cancellation selection column 103 shown in FIG. Since the value correction execution (on) is selected, the detected value correction unit 98 functions.

The detection value correction unit 98 corrects the temperature detection value T2 of the cylinder 41 based on the structural difference between the second structure and the first structure. For example, when the heat transfer amount EH becomes smaller due to the structure of the injection device changing from the first structure to the second structure, the detection value correction unit 98 largely corrects the detection value T2 of the temperature of the cylinder 41. Since the detected value after correction is large, the operation amount generation unit 97 reduces the supply current value of the heater 48 so as to eliminate the deviation from the set value. As a result, the heating amount SH2'of the cylinder 41 becomes smaller, the heating amount MH2'of the molding material of the second structure becomes equal to the heating amount MH1 of the molding material of the first structure, and the temperature of the molding material of the second structure becomes high. It becomes equivalent to the temperature of the molding material of the first structure. The detection value correction unit 98 detects the temperature of the cylinder 41 based on the structural difference between the second structure and the first structure so that the temperature of the molding material of the second structure becomes equal to the temperature of the molding material of the first structure. Correct the value T2. Therefore, the same temperature setting value can be used in injection molding between the injection molding machine having the first structure and the injection molding machine having the second structure, and compatibility of the settings can be ensured.

The heating amount SH2'of the cylinder 41 shown in FIG. 5C is smaller than the heating amount SH2 of the cylinder 41 shown in FIG. 5B, so that the heat transfer amount EH2'shown in FIG. 5C is shown in FIG. It is smaller than the transfer heat amount EH2 shown in 5 (b). The ratio of EH2 to SH2 and the ratio of EH2'to SH2'are equal. The detection value correction unit 98 moves due to a change in the heating amount of the cylinder 41 (difference between SH2'and SH2) so that the temperature of the molding material of the second structure becomes equal to the temperature of the molding material of the first structure. The detected value T2 of the temperature of the cylinder 41 may be corrected based on the change in the amount of heat (difference between EH2'and EH2).

Although the embodiments of the injection molding machine have been described above, the present invention is not limited to the above-described embodiments and the like, and various modifications are made within the scope of the gist of the present invention described in the claims. Improvement is possible.

2 Injection molding machine 4 Network 10 Mold clamping device 12 Fixed platen 13 Movable platen 15 Support platen 20 Toggle mechanism 21 Mold clamping motor 40 Injection device 41 Cylinder 41b Insulation ring 42 Nozzle 43 Screw 45 Weighing motor 46 Injection motor 47 Pressure detector 50 Ejector Device 51 Ejector motor 52 Motion conversion mechanism 53 Ejector rod 90 Control device 95 Input device 96 Output device 100 Operation screen

Claims (5)

A control device for generating an operation amount of a controlled object portion based on a set value of a controlled amount indicating a molding condition and a detected value of the controlled amount is provided.
The controlled amount and the manipulated amount have a different relationship depending on the difference in the structure of the injection molding machine.
When the control device uses the set value when the structure is a different structure from the current structure to generate the operation amount when the structure is the current structure, the control of the different structure the relationship between the amount and the operation amount, the said detection value is corrected based on the relationship and the difference of said controlled variable and the manipulated variable of the current structure, the said set value and the detected value of the corrected An injection molding machine that generates the operation amount based on the above. The injection molding machine according to claim 1, wherein the relationship between the controlled variable and the manipulated variable is represented by a transfer function. The control device stores the correction amount of the detected value for each candidate of the structure in advance, and when one candidate is selected from the plurality of candidates of the structure, the correction amount corresponding to the selected structure is used. The injection molding machine according to claim 1 or 2 , wherein the detected value is corrected. The injection molding machine according to any one of claims 1 to 3, wherein the control device stores the set value in association with the structure. When the control device uses the set value when the structure is the different structure to generate the operation quantity when the structure is the current structure, the control device is a predetermined physical quantity different from the control quantity. The injection molding machine according to any one of claims 1 to 4 , wherein the detected value is corrected so that is constant.

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