Injection molding machine and controller

Abstract

To provide an injection molding machine capable of suppressing jitter in a timing of executing high-priority tasks.SOLUTION: A controller that controls a mold clamping device, an injection device, and an ejector device has a cache memory consisting of multiple layers and a processor. The processor executes a plurality of tasks, each with a corresponding priority, using the cache memory. The processor determines a hierarchy of a cache memory to be used based on a priority of a task to be executed.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an injection molding machine and a controller for operating an injection molding machine or the like. [Background technology]

[0002] In an injection molding machine, multiple tasks are periodically executed, such as current control of the clamping motor, injection motor, etc., data acquisition from various sensors, speed control and position control of various moving parts, communication control, etc. (For example, see Patent Document 1, etc.). A high-speed microprocessor used in a controller that controls an injection molding machine, etc., is equipped with multiple hierarchical cache memories in order to execute these multiple tasks at high speed. Controllers that control various machines use a multitasking function to simultaneously execute multiple tasks with different priorities. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-132229 A Summary of the Invention [Problem to be solved by the invention]

[0004] Among various tasks, there are those that must be executed at an almost exact constant cycle (high priority tasks), those that allow a certain degree of jitter in their execution cycle, and those that are executed irregularly as required. It has been found that in conventional injection molding machines and the like, jitter may occur in the execution cycle of high priority tasks. An object of the present invention is to provide an injection molding machine and a controller that are capable of suppressing jitter in the timing of executing high priority tasks. [Means for solving the problem]

[0005] According to one aspect of the present invention, a cache memory having a plurality of hierarchical levels including a first hierarchical level and a second hierarchical level having a slower access speed than the first hierarchical level; Multiple tasks with each assigned priority Each command and data of the task The cache memory Store in The processor that runs it Equipped with the plurality of tasks include a first task that is executed periodically and a second task that has a lower priority than the first task, The processor, The instructions and data of the first task are stored in the cache memory of the first hierarchy, and even when the first task is completed, the instructions and data of the first task are not removed from the cache memory of the first hierarchy for execution of the second task, and the instructions and data of the second task are not removed from the cache memory of the first hierarchy for execution of the second task. However, a controller is provided that determines the hierarchy of the cache memory to be used based on the priority of the task so as not to use the first hierarchy cache memory.

[0006] According to another aspect of the invention, A mold clamping device that clamps the mold; an injection device that fills the mold clamped by the mold clamping device with a molding material; an ejector device that removes a molded product from the mold after the molding material filled by the injection device has solidified; The controller controls the mold clamping unit, the injection unit, and the ejector unit; Injection molding machine equipped with is provided. Effect of the Invention

[0007] Since the hierarchy of the cache memory to be used is determined based on the priority of the task to be executed, it is possible to separate the hierarchy of the cache memory used by a high-priority task from the hierarchy of the cache memory used by a low-priority task. This prevents the instructions and data of a high-priority task from being evicted from the cache memory in order to execute a low-priority task. Therefore, a high-priority task can be executed without restoring the instructions and data of the high-priority task to the cache memory. As a result, it is possible to suppress jitter in the timing of executing a high-priority task. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a block diagram of a controller according to an embodiment. [Diagram 2]FIG. 2 is a diagram showing the relationship between the priorities assigned to multiple tasks executed by the controller and the memory hierarchy. [Diagram 3] FIG. 3 is a flowchart showing how a memory to be used is determined when a task is started. [Figure 4] FIG. 4 is a timing chart in which a controller according to a comparative example periodically executes a task T1 of priority TP1 with a cycle p1, and periodically executes a task T2 of priority TP4 with a cycle longer than the cycle p1 in parallel with the task of priority TP1. [Diagram 5] FIG. 5 is a timing chart in which a controller according to an embodiment periodically executes a task T1 of priority TP1 with a cycle p1, and periodically executes a task T2 of priority TP4 with a cycle longer than the cycle p1 in parallel with the task of priority TP1. [Figure 6] FIG. 6 is a flowchart showing a process for determining a memory to be used when one task is started in a controller according to another embodiment. [Figure 7] FIG. 7 is a schematic diagram of an injection molding system according to yet another embodiment when mold opening is completed. [Figure 8] FIG. 8 is a schematic diagram of the injection molding system shown in FIG. 7 during mold clamping. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] A controller according to an embodiment of the present invention will be described with reference to FIGS. 1 is a block diagram of a controller 90 according to an embodiment. The controller 90 according to the embodiment includes a processor (CPU) 91, a cache memory consisting of multiple hierarchical levels, a main memory 92C, an auxiliary storage device 93, and an input / output interface 94. The cache memory consisting of multiple hierarchical levels includes a primary cache memory 92A and a secondary cache memory 92B.

[0010] The access speed of the primary cache memory 92A is faster than the access speed of the secondary cache memory 92B, which in turn is faster than the access speed of the main memory 92C. For example, static RAMs are used for the primary cache memory 92A and the secondary cache memory 92B, and dynamic RAM is used for the main memory 92C.

[0011] The auxiliary storage device 93 may be, for example, a removable recording medium such as a USB memory or an SD card, a serial flash memory, a hard disk drive (HDD), or a solid state drive (SSD). Various programs and various data are stored in the auxiliary storage device 93. The CPU 91 transfers the programs and data from the auxiliary storage device 93 to the main memory 92C and executes the programs stored in the main memory 92C. In addition, as necessary, the CPU 91 transfers the programs (instructions) and data in the main memory 92C to the primary cache memory 92A or the secondary cache memory 92B and executes various tasks using the primary cache memory 92A or the secondary cache memory 92B.

[0012] The controller 90 transmits various signals, such as control signals and information signals, to the controlled machine 100 via the input / output interface 94, and receives various signals, such as control signals and information signals, from the controlled machine 100.

[0013] 2 is a diagram showing an example of the relationship between the priorities assigned to a plurality of tasks executed by the controller 90 and memory hierarchies. Each of a plurality of tasks executed by the CPU 91 is assigned one of nine levels of priority, ranging from the highest priority TP1 to the lowest priority TP9. A memory hierarchy is assigned to the priority of a task. Memories in memory hierarchies L1, L2, and L3 correspond to the primary cache memory 92A, secondary cache memory 92B, and main memory 92C, respectively. Information defining the assignment of task priorities to memory hierarchies is stored in the main memory 92C.

[0014] In this embodiment, the memory in memory hierarchy L1, i.e., the primary cache memory 92A, is assigned to the priorities TP1, TP2, and TP3. The memory in memory hierarchy L2, i.e., the secondary cache memory 92B, is assigned to the priorities TP4, TP5, TP6, and TP7. The memory in memory hierarchy L3, i.e., the main memory 92C, is assigned to the priorities TP8 and TP9.

[0015] As an example, the highest priority TP1 is assigned to a task that executes a process of monitoring the controlled machine 100 for abnormalities.

[0016] The second highest priority TP2 is assigned to the task of controlling the current of the controlled machine 100. The current control is, for example, feedback control performed on a device that passes a current of a commanded magnitude, such as an inverter.

[0017] The third highest priority TP3 is assigned to the task of controlling the speed of the controlled machine 100. The speed control is, for example, feedback control performed on an actuator that moves a movable part at a commanded speed.

[0018] The fourth highest priority TP4 is assigned to a task for performing position control of the controlled machine 100. The position control is, for example, feedback control performed on an actuator that moves a movable part to a commanded position.

[0019] The fifth highest priority TP5 is assigned to the task that performs the host controller communication processing of the controlled machine 100. The host controller communication processing is, for example, processing in which the controller 90 communicates with the host controller. The host controller is, for example, a management server that manages multiple controlled machines 100, and the controller 90 communicates with the host controller via a communication network.

[0020] The sixth highest priority TP6 is assigned to the task of generating a trajectory of the controlled machine 100. Trajectory generation is a process of generating a time-varying profile of the screw speed when the resin is filled into the mold.

[0021] The seventh highest priority TP7 is assigned to a task that performs various sequence controls of the controlled machine 100. The sequence control is a control that sequentially executes a series of processes such as a mold closing process, a mold clamping process, a resin filling process, a mold opening process, and a molded product ejection process.

[0022] The eighth highest priority TP8 is assigned to a task that executes a maintenance function for the controlled machine 100. The lowest priority TP9 is assigned to a task that executes a log storage function for the controlled machine 100.

[0023] 3 is a flowchart showing how the CPU 91 determines the memory to be used when a task is started. The CPU 91 determines the memory hierarchy assigned to the priority of the started task by referring to the information defining the assignment shown in FIG.

[0024] When the memory hierarchical level assigned to the priority of the task to be executed is L1, the CPU 91 executes the task using the primary cache memory 92A (step S1). When the instructions and data of the task to be executed are not stored in the primary cache memory 92A, the instructions and data are stored in the primary cache memory 92A, and then the task is executed using the primary cache memory 92A.

[0025] When the memory hierarchy assigned to the priority of the task to be executed is L2, the CPU 91 executes the task using the secondary cache memory 92B (step S2). When the instructions and data of the task to be executed are not stored in the secondary cache memory 92B, the instructions and data are stored in the secondary cache memory 92B, and then the task is executed using the secondary cache memory 92B.

[0026] When the memory hierarchy assigned to the priority of the task to be executed is L3, the CPU 91 executes the task using the main memory 92C without using the cache memory (step S3).

[0027] Next, the excellent effects of this embodiment will be described with reference to FIGS. 4 is a timing chart in which a controller according to a comparative example periodically executes a task T1 with a priority level TP1 at a period p1, and periodically executes a task T2 with a priority level TP4 at a period longer than the period p1 in parallel with the task with the priority level TP1. In the comparative example, a specific memory hierarchy is not assigned to the priority level of a task, and tasks of any priority level preferentially use the primary cache memory 92A.

[0028] When task T1 with priority TP1 is started (time t1), the CPU 91 executes task T1. At this time, it is assumed that the instructions and data of task T1 are already stored in the primary cache memory 92A. The darkly hatched areas in the timing chart shown in the primary cache memory 92A row in Fig. 4 represent the areas of the storage area of ​​the primary cache memory 92A that are occupied by the instructions and data of task T1, and the white areas represent free areas.

[0029] When task T1 ends, task T2, which has a lower priority, is started (time t2). When task T2 is started, the CPU 91 judges whether or not the instructions and data of task T2 have been stored in the primary cache memory 92A. In this comparative example, at time t2, the instructions and data of task T1 are stored in the primary cache memory 92A, but the instructions and data of task T2 are not stored. At this time, the CPU 91 stores some of the instructions and data of task T2 from the main memory 92C in the primary cache memory 92A. The lightly hatched area in the timing chart shown in the primary cache memory 92A row in FIG. 4 represents the area of ​​the storage area of ​​the primary cache memory 92A occupied by the instructions and data of task T2.

[0030] When the primary cache memory 92A runs out of free space, the CPU 91 stores some of the instructions and data of task T2 in the primary cache memory 92A, and evicts some of the instructions and data of task T1 from the primary cache memory 92A.

[0031] During the execution of task T2, when an instruction that is not stored in the primary cache memory 92A is to be executed or data that is to be used is to be used, the instruction to be executed or data to be used is stored in the primary cache memory 92A. After executes a process of storing a part of the instructions and data of task T2 in the primary cache memory 92A, and a process of evicting a part of the instructions and data of task T1 from the primary cache memory 92A. As a result, the area occupied by the instructions and data of task T2 increases in the storage area of ​​the primary cache memory 92A. In FIG. 4, as an example, the area occupied by the instructions and data of task T2 increases linearly over time, but in reality, this does not necessarily occur linearly.

[0032] When the next execution period of task T1 arrives, the CPU 91 suspends the execution of task T2 and starts task T1 (time t3). At this time, some of the instructions and data of task T1 have been evicted from the primary cache memory 92A. When executing an instruction evicted from the primary cache memory 92A or using the evicted data, the CPU 91 restores the instruction to be executed and the data to be used in the primary cache memory 92A, and evicts some of the instructions and data of task T2 from the primary cache memory 92A. In this way, task T1 is executed while executing a process of storing the instructions and data of task T1 in the primary cache memory 92A and a process of evicting the instructions and data of task T2 from the primary cache memory 92A.

[0033] During the period from time t3 when task T1 is started to time t4 when task T1 ends, the area of ​​the storage area of ​​the primary cache memory 92A occupied by the instructions and data of task T1 increases. When task T1 ends at time t4, the CPU 91 resumes task T2 from the interruption point. At this time, as in the period from time t2 to t3, the area of ​​the storage area of ​​the primary cache memory 92A occupied by the instructions and data of task T2 increases over time.

[0034] When the next execution cycle of task T1 arrives, the CPU 91 suspends task T2 and starts task T1 (time t5). During the period from when task T1 starts (time t5) to when task T1 ends (time t6), the area of ​​the storage area of ​​the primary cache memory 92A occupied by the instructions and data of task T1 increases, similar to the period from time t3 to t4.

[0035] When task T1 ends at time t6, the CPU 91 resumes the suspended task T2 from the interruption point. Task T2 ends at time t7, before the execution period of task T1 arrives. During the period from time t6 to t7, similar to the period from time t2 to t3, the area of ​​the storage area of ​​the primary cache memory 92A occupied by the instructions and data of task T2 increases. During the period from time t7 to the arrival of the next execution period of task T1, instructions and data are not stored in the primary cache memory 92A.

[0036] When the next execution period of task T1 arrives, the CPU 91 starts task T1 (time t8). During the period from when task T1 starts (time t8) to when task T1 ends (time t9), the area of ​​the storage area of ​​the primary cache memory 92A occupied by the instructions and data of task T1 increases, similar to the period from time t3 to t4.

[0037] When task T1 ends (time t9), the CPU 91 waits until time t10 when task T1 is next started. When task T1 is started at time t10, all instructions and data of task T1 remain in the primary cache memory 92A. Therefore, the CPU 91 executes task T1 without performing a process of storing instructions and data of task T1 in the primary cache memory 92A.

[0038] During the period t11-t12 from time t11 until the next execution cycle of task T1 arrives, all instructions and data of task T1 are maintained in the primary cache memory 92A. Therefore, during the period from time t12-t13, similar to the period from time t10-t11, the CPU 91 executes task T1 without performing a process of storing instructions and data of task T1 in the primary cache memory 92A.

[0039] As described above, during the periods from time t3 to t4, from time t5 to t6, and from time t8 to t9, the CPU 91 executes task T1 while executing the process of storing the instructions and data of task T1 in the primary cache memory 92A. In contrast, during the periods from time t1 to t2, from time t10 to t11, and from time t12 to t13, the CPU 91 executes task T1 without executing the process of storing the instructions and data of task T1 in the primary cache memory 92A. This causes variation in the time from the start to the end of task T1. The variation in the time from the start to the end of task T1 causes jitter in the timing of executing a specific instruction of task T1.

[0040] FIG. 5 is a timing chart in which the controller 90 (FIG. 1) of the embodiment periodically executes a task T1 of priority TP1 with a period p1, and periodically executes a task T2 of priority TP4 with a period longer than the period p1 in parallel with the task of priority TP1.

[0041] Task T1 is started at time t1 and terminated at time t2. At this time, it is assumed that the instructions and data of task T1 are stored in the primary cache memory 92A. The darkly hatched areas in the timing chart shown in the primary cache memory 92A row in Fig. 5 represent the areas of the storage area of ​​the primary cache memory 92A that are occupied by the instructions and data of task T1, and the white areas represent free areas.

[0042] When task T1 ends (time t2), task T2, which has a lower priority, is started. A memory hierarchy L2 is assigned to the priority TP4 of task T2 (FIG. 2). Therefore, the CPU 91 executes task T2 while executing a process of storing the instructions and data of task T2 from the main memory 92C to the secondary cache memory 92B. The instructions and data of task T1 are not evicted from the primary cache memory 92A. The lightly hatched area in the timing chart shown in the secondary cache memory 92B row in FIG. 5 represents the area of ​​the memory area of ​​the secondary cache memory 92B occupied by the instructions and data of task T2, and the white area represents the free area. During the execution of task T2, the area of ​​the memory area of ​​the secondary cache memory 92B occupied by the instructions and data of task T2 increases.

[0043] When the execution period of task T1 arrives, the CPU 91 suspends task T2 and starts task T1 (time t4). At this time, since the instructions and data of task T1 remain in the primary cache memory 92A, the CPU 91 executes task T1 without executing the process of storing the instructions and data of task T1 in the primary cache memory 92A. When task T1 ends, the CPU 91 resumes the suspended task T2 from the interruption point (time t6). During the period from time t6 to time t7 when the next execution period of task T1 arrives, the area occupied by the instructions and data of task T2 increases in the storage area of ​​the secondary cache memory 92B.

[0044] At time t7, the CPU 91 starts task T1, which ends at time t8. When task T1 ends, the CPU 91 resumes the suspended task T2 from the interruption point (time t8). During the period from time t8 to time t9 when task T2 ends, the area of ​​the storage area of ​​the secondary cache memory 92B occupied by the instructions and data of task T2 increases. Thereafter, the CPU 91 periodically starts task T1 at times t10, t11, and t12.

[0045] In this embodiment, when task T2 is executed, the instructions and data of task T1, which has a higher priority, are not evicted from the primary cache memory 92A. Even at times t4 and t7 when task T2 is suspended, there is no need to store the instructions and data of task T1 back in the primary cache memory 92A. As a result, the time from the start to the end of task T1 is almost the same in any cycle. For this reason, jitter is unlikely to occur in the timing of executing a specific instruction of task T1.

[0046] For example, in a process in which feedback control is performed at short intervals, jitter is unlikely to occur in the execution timing of a specific command in a feedback control task, which can improve the accuracy of the feedback control.

[0047] Furthermore, in the comparative example, the time required to re-store the instructions and data of task T1 in the primary cache memory 92A is required during the periods from time t3 to t4, from time t5 to t6, and from time t8 to t9. In contrast, in this embodiment, the time required to re-store the instructions and data of task T1 in the primary cache memory 92A is not required, and therefore the utilization efficiency of the CPU 91 can be improved.

[0048] Next, a modification of the above embodiment will be described. In the above embodiment, the cache memory is divided into two hierarchical levels, the primary and secondary levels, but the number of hierarchical levels of the cache memory may be three or more. In this case, the priority of a task may be associated with either the cache memory or the main memory in the third or higher level.

[0049] Next, a controller according to another embodiment will be described with reference to Fig. 6. Below, a description of the configuration common to the controller 90 according to the embodiment shown in Figs. 1 to 5 will be omitted.

[0050] Fig. 6 is a flow chart for determining a memory to be used when one task is started in the controller 90 according to this embodiment. In the embodiment shown in Fig. 3, when the memory hierarchy assigned to the priority of the task to be executed is L2, the CPU 91 uses the secondary cache memory 92B. In contrast, in the embodiment shown in Fig. 6, when the priority of the task to be executed is TP2, it is determined whether or not there is any available area remaining in the primary cache memory 92A other than the area assigned to the task with a higher priority than the priority of the task to be executed (step S4).

[0051] If there is no available area remaining in the primary cache memory 92A, the secondary cache memory 92B is used to execute the task with priority TP2 (step S2), as in the embodiment shown in Fig. 3. If there is available area remaining in the primary cache memory 92A, the primary cache memory 92A is used to execute the task with priority TP2 (step S1).

[0052] Next, the excellent effects of the embodiment shown in FIG. 6 will be described. In this embodiment, the instructions and data of the task with the priority level TP1 are not evicted from the primary cache memory 92A in order to execute a task with a lower priority level. Therefore, as in the embodiment described with reference to Figures 1 to 5, the excellent effect of preventing jitter from occurring in the execution timing of a high-priority task that is executed periodically can be obtained.

[0053] Next, with reference to Figs. 7 and 8, an injection molding system including an injection molding machine equipped with a controller 90 according to any of the above-described embodiments will be described as another embodiment.

[0054] Figures 7 and 8 are schematic diagrams of the injection molding system 1 according to this embodiment. Figure 7 shows the state when the injection molding machine 2 has completed mold opening, and Figure 8 shows the state when the injection molding machine 2 has completed mold clamping. The injection molding system 1 includes multiple injection molding machines 2, an external device 4, and a communication network 6. The multiple injection molding machines 2 have the same configuration. Figures 7 and 8 show the detailed configuration of only one injection molding machine 2. Each of the multiple injection molding machines 2 performs a series of operations to obtain a molded product.

[0055] The multiple injection molding machines 2 communicate with an external device 4 via a communication network 6. The external device 4 is, for example, a management terminal or a management server that manages the operating status of the multiple injection molding machines 2 in a factory. The injection molding machines 2 can acquire various information from the external device 4, such as information on various settings and information on maintenance such as update programs. The multiple injection molding machines 2 also perform bidirectional communication with each other via the communication network 6. This allows each of the multiple injection molding machines 2 to acquire various information from the other injection molding machines 2, such as information on various settings and information on maintenance such as update programs. For example, a priority level TP5 (FIG. 2) is assigned to the tasks that realize the functions of these communication processes.

[0056] The injection molding machine 2 includes a frame Fr, a mold clamping device 10, an injection device 40, an ejector device 50, a controller 90, an input device 95, an output device 96, a storage device 97, and a power relay 98. As the controller 90, the controller 90 according to the embodiment shown in Figures 1 to 3 or the embodiment shown in Figure 6 is used.

[0057] First, a description will be given of the mold clamping unit 10 and the ejector unit 50. In the following description of the mold clamping unit 10, etc., the moving direction of the movable platen 13 when the mold is closed (to the right in Figs. 7 and 8) is defined as the front, and the moving direction of the movable platen 13 when the mold is opened (to the left in Figs. 7 and 8) is defined as the rear.

[0058] The mold clamping device 10 performs mold closing, mold clamping, and mold opening of the mold device 30. The mold clamping device 10 includes a fixed platen 12, a movable platen 13, a support platen 15, tie bars 16, a toggle mechanism 20, a mold clamping motor 21, and a motion conversion mechanism 25. The fixed platen 12 is fixed to a frame Fr. A fixed mold 32 is attached to the surface of the fixed platen 12 facing the movable platen 13.

[0059] The movable platen 13 is movable along a guide mechanism 17 fixed on the frame Fr. Specifically, the movable platen 13 is movable forward and backward relative to the fixed platen 12. A movable mold 33 is attached to the surface of the movable platen 13 facing the fixed platen 12. The fixed mold 32 and the movable mold 33 constitute a mold device 30. Mold closing, mold clamping, and mold opening are performed by moving the movable platen 13 forward and backward relative to the fixed platen 12.

[0060] The support platen 15 is connected to the fixed platen 12 with a gap therebetween, and is placed on the frame Fr so as to be movable in the mold opening / closing direction.

[0061] A plurality of tie bars 16 connect the fixed platen 12 and the support platen 15 at intervals. Each of the tie bars 16 is parallel to the mold opening / closing direction and extends according to the clamping force. A clamping force detector 18 is attached to at least one of the tie bars 16. As the clamping force detector 18, for example, a strain gauge is used which detects the clamping force by measuring the amount of distortion of the tie bar 16. A signal indicating the detection result by the clamping force detector 18 is input to the controller 90.

[0062] The toggle mechanism 20 moves the movable platen 13 relative to the fixed platen 12. The toggle mechanism 20 is composed of a crosshead 20a and a pair of link groups, etc. Each link group has a plurality of links 20b, 20c that are connected by pins or the like so as to be freely flexible and extensible. One link 20b is attached to the movable platen 13 so as to be freely swingable, and the other link 20c is attached to the support platen 15 so as to be freely swingable. When the crosshead 20a is advanced or retreated, the multiple links 20b, 20c are flexed and extended, and the movable platen 13 advances or retreats relative to the support platen 15.

[0063] The mold clamping motor 21 is attached to the support platen 15, and moves the crosshead 20a forward and backward, thereby moving the movable platen 13 forward and backward.

[0064] The motion conversion mechanism 25 converts the rotational motion of the mold clamping motor 21 into linear motion and transmits the linear motion to the crosshead 20a. As the motion conversion mechanism 25, for example, a ball screw mechanism is used.

[0065] The operation of the mold clamping unit 10 is controlled by a controller 90. Specifically, the controller 90 controls the operation of the mold clamping unit 10 in a mold closing process, a mold clamping process, and a mold opening process.

[0066] In the mold closing process, the controller 90 drives the mold clamping motor 21 to advance the crosshead 20a at a set speed, thereby advancing the movable platen 13 and bringing the movable mold 33 into contact with the fixed mold 32. The position and speed of the crosshead 20a are detected, for example, by the encoder 21a of the mold clamping motor 21. A signal indicating the detection result of the encoder 21a is input to the controller 90. A task for controlling the speed of the mold clamping motor 21 is assigned, for example, a priority level TP3 (FIG. 2).

[0067] In the mold clamping process, the controller 90 further drives the mold clamping motor 21 to move the crosshead 20a further forward to a set position. During the mold clamping process shown in FIG. 8, a cavity 34 is formed between the movable mold 33 and the fixed mold 32. A liquid molding material is filled into the cavity 34. The molding material filled in the cavity 34 is solidified to obtain a molded product. For example, a priority level P4 is assigned to a task that controls the position of the crosshead 20a in the mold clamping process.

[0068] In the mold opening process, the controller 90 drives the mold clamping motor 21 to move the crosshead 20a backward at a set speed, thereby moving the movable platen 13 backward. As a result, the movable mold 33 moves away from the fixed mold 32.

[0069] The ejector device 50 ejects a molded product from the mold device 30. The ejector device 50 has 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 rod 53 is inserted into a through hole of the movable platen 13 and is movable in the mold opening and closing direction. The motion conversion mechanism 52 converts the rotational motion of the ejector motor 51 into linear motion and transmits it to the ejector rod 53. For example, a ball screw mechanism is used as the motion conversion mechanism 52. The movable member 35 is disposed in the movable mold 33. The front end of the ejector rod 53 is in contact with the movable member 35.

[0070] The operation of the ejector device 50 is controlled by the controller 90. Specifically, the controller 90 controls the operation of the ejector device 50 in the ejection process and the like.

[0071] In the ejection process, the controller 90 drives the ejector motor 51 to advance the ejector rod 53, thereby advancing the movable member 35 and ejecting the molded product. Thereafter, the controller 90 drives the ejector motor 51 to retract the ejector rod 53, thereby retracting the movable member 35 to its original position. The position and speed of the ejector rod 53 are detected, for example, by the encoder 51a of the ejector motor 51. A signal indicating the detection result of the encoder 51a is input to the controller 90. For example, a priority TP3 (FIG. 2) is assigned to the task of controlling the speed of the ejector motor 51.

[0072] 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 (leftward in Figs. 7 and 8) is defined as the front, and the moving direction of the screw 43 during metering (rightward in Figs. 7 and 8) is defined as the rear.

[0073] The injection unit 40 is mounted on a slide base Sb which is movable in the front-rear direction relative to the frame Fr, and is movable in the front-rear direction relative to the mold device 30. The injection unit 40 comes into contact with the mold device 30 and fills the cavity 34 (FIG. 8) of the mold device 30 with molding material. The injection unit 40 has a cylinder 41, a nozzle 42, a screw 43, a cooler 44, a metering motor 45, an injection motor 46, a pressure detector 47, a heater 48, and a temperature detector 49.

[0074] The cylinder 41 heats the molding material supplied inside from a supply port 41a. The supply port 41a is disposed at the rear of the cylinder 41. A cooler 44 such as a water-cooled cylinder is provided on the outer periphery of the rear of the cylinder 41. A heater 48 such as a band heater and a temperature detector 49 are disposed on the outer periphery of the cylinder 41, forward of the cooler 44.

[0075] The cylinder 41 is divided into a plurality of zones in its axial direction (left and right direction in Figs. 7 and 8). A heater 48 and a temperature detector 49 are disposed in each zone of the cylinder 41. The controller 90 controls the heater 48 for each zone so that the actual temperature measured by the temperature detector 49 becomes the set temperature. A priority level TP2, for example, is assigned to the task of controlling the heater 48.

[0076] The screw 43 is disposed within the cylinder 41 so as to be rotatable and movable in the front-rear direction.

[0077] The metering motor 45 rotates the screw 43 to send the molding material forward along the spiral groove of the screw 43. As the molding material is sent forward, it is melted by heat from the cylinder 41. As the liquid molding material is sent to the front of the screw 43 and accumulates at the front of the cylinder 41, the screw 43 moves backward.

[0078] The injection motor 46 moves the screw 43 forward, thereby injecting the liquid molding material accumulated in the front part of the cylinder 41 from the cylinder 41 and filling the cavity 34 (FIG. 8) of the mold device 30. Thereafter, the injection motor 46 pushes the screw 43 forward, applying pressure to the molding material in the cavity 34 of the mold device 30. This makes it possible to replenish the shortage of molding material. A motion conversion mechanism that converts the rotational motion of the injection motor 46 into linear motion of the screw 43 is provided between the injection motor 46 and the screw 43.

[0079] The pressure detector 47 is disposed between the injection motor 46 and the screw 43, and detects the pressure that the screw 43 receives from the molding material, the back pressure on the screw 43, etc. A signal indicating the detection result by the pressure detector 47 is input to the controller 90.

[0080] The operation of the injection unit 40 is controlled by a controller 90. The controller 90 controls the operation of the injection unit 40 in the filling process, the pressure holding process, and the measuring process.

[0081] In the filling step, the controller 90 drives the injection motor 46 to advance the screw 43 at a set speed, and fills the liquid molding material accumulated in the front part of the cylinder 41 into the cavity 34 of the mold device 30. The position and speed of the screw 43 are detected, for example, by an encoder 46a of the injection motor 46. A signal indicating the detection result by the encoder 46a is input to the controller 90. When the position of the screw 43 reaches a set position, the filling step is switched to the pressure holding step. The task of controlling the speed of the screw 43 is assigned, for example, a priority TP3 (FIG. 2), and the task of controlling the position is assigned, for example, a priority TP4 (FIG. 2).

[0082] In the pressure holding step, the controller 90 drives the injection motor 46 to push the screw 43 forward at a set pressure, thereby applying pressure to the molding material in the cavity 34 of the mold device 30. The pressure applied to the molding material is detected by, for example, a pressure detector 47. A signal indicating the detection result by the pressure detector 47 is input to the controller 90. For example, a priority level TP3 (FIG. 2) is assigned to the task of controlling the pressure.

[0083] With pressure being applied to the molding material, the molding material in the cavity 34 of the mold device 30 is gradually cooled, and when the pressure-holding step is completed, the entrance to the cavity 34 is blocked with solidified molding material. After the pressure-holding step, the cooling step is started. In the cooling step, the molding material in the cavity 34 is solidified.

[0084] In the metering process, the controller 90 drives the metering motor 45 to rotate the screw 43 at a set rotation speed, and sends the molding material forward along the spiral groove of the screw 43. As a result, the molding material melts. As the liquid molding material is sent to the front of the screw 43 and accumulates at the front of the cylinder 41, the screw 43 retreats. The rotation speed of the screw 43 is detected, for example, by the encoder 45a of the metering motor 45. A signal indicating the detection result by the encoder 45a is input to the controller 90. The task of controlling the rotation speed of the screw 43 is assigned, for example, a priority TP3 (FIG. 2).

[0085] In the metering process, the controller 90 may apply a set back pressure to the screw 43 by driving the injection motor 46 in order to limit abrupt retraction of the screw 43. The back pressure on the screw 43 is detected by, for example, a pressure detector 47. A signal indicating the detection result by the pressure detector 47 is input to the controller 90. When the screw 43 retracts to a set position and a predetermined amount of molding material is accumulated in front of the cylinder 41, the metering process ends. For example, a priority TP4 (FIG. 2) is assigned to the task that controls the injection motor 46 when applying back pressure.

[0086] A user inputs various operations to the injection molding machine 2 through the input device 95. The input device 95 transmits an operation signal corresponding to the operation input by the user to the controller 90. A task for which the controller 90 receives a signal from the input device 95 is assigned a priority level of, for example, TP5 (FIG. 2).

[0087] The output device 96 displays various information under the control of the controller 90. For example, the output device 96 displays information relating to the current state of various settings in the injection molding machine 2.

[0088] The storage device 97 is communicably connected to the controller 90. For example, a USB memory, a DVD drive with a DVD medium inserted, or the like is used as the storage device 97. For example, a priority level TP5 (FIG. 2) is assigned to a task in which the controller 90 communicates with the storage device 97.

[0089] The power relay 98 is inserted in a power path between a commercial power source and a drive device of the injection molding machine 2. When the injection molding machine 2 is started, the power relay 98 is turned on. This enables power to be supplied to the drive device.

[0090] Next, the advantageous effects of the injection molding system 1 according to this embodiment will be described. The injection molding system 1 according to this embodiment uses the controller 90 according to the embodiment shown in Figures 1 to 3 or the embodiment shown in Figure 6. This makes it possible to reduce jitter in the execution timing of a high-priority task for controlling an actuator such as a motor. As a result, it is possible to improve the accuracy of actuator control.

[0091] The above-mentioned embodiments are merely examples, and it goes without saying that partial replacement or combination of the configurations shown in different embodiments is possible. Similar effects due to similar configurations of multiple embodiments are not mentioned in each embodiment. Furthermore, the present invention is not limited to the above-mentioned embodiments. For example, it will be obvious to those skilled in the art that various modifications, improvements, combinations, etc. are possible. [Explanation of symbols]

[0092] 1. Injection Molding System 2 Injection molding machine 4 External device 6. Communication Network 10 Mold clamping device 12 Fixed Platen 13 Movable platen 15 Support Platen 16 Tie bar 17 Guide mechanism 18 Clamping force detector 20 Toggle Mechanism 20a Crosshead 20b Link 20c Link 21 Clamping motor 21a Encoder 25 Motion conversion mechanism 30 Mold Equipment 32 Fixed mold 33 Movable mold 34 Cavity 35 Movable parts 40 Injection device 41 Cylinder 41a Supply port 42 Nozzle 43 Screw 44 Cooler 45 Metering motor 45a Encoder 46 Injection motor 46a Encoder 47 Pressure detector 48 Heater 49 Temperature Sensor 50 Ejector device 51 Ejector motor 51a Encoder 52 Motion conversion mechanism 53 Ejector rod 90 Controller 91 CPU 92A Primary cache memory 92B Secondary cache memory 92C Main memory 93 Secondary storage device 94 Input / Output Interface 95 Input Devices 96 Output Devices 97 Storage device 98 Power Relay 100 Controlled Machine

Claims

1. a cache memory having a plurality of hierarchical levels including a first hierarchical level and a second hierarchical level having an access speed slower than that of the first hierarchical level; a processor that executes a plurality of tasks, each of which is assigned a priority, by storing instructions and data for each of the tasks in the cache memory; Equipped with the plurality of tasks include a first task that is executed periodically and a second task that has a lower priority than the first task, The processor stores instructions and data of the first task in the first hierarchical cache memory, and a controller that determines the hierarchical level of the cache memory to be used based on the priority of a task so that the second task does not use the first hierarchical cache memory even when the first task is completed, without evicting the instructions and data of the first task from the first hierarchical cache memory for execution of the second task.

2. A mold clamping device that clamps the mold; an injection device that fills the mold clamped by the mold clamping device with a molding material; an ejector device that removes a molded product from the mold after the molding material filled by the injection device has solidified; The controller according to claim 1 , which controls the mold clamping unit, the injection unit, and the ejector unit. An injection molding machine equipped with

Images