Molding machines and spraying equipment

Abstract

To provide a molding machine capable of improving precision in the control of a mold temperature.SOLUTION: A die cast machine 1 repeats a molding cycle MC and comprises: a machine body 3; a cooling part 13; and a control device 5. The machine body 3 performs mold closing, injection and mold opening in each molding cycle in order. The cooling part 13 cools a mold 101 in each molding cycle. The control device 5 controls the cooling part 13 based on a signal from a temperature sensor 59 detecting the temperature of the mold 101. The cooling part 13 comprises a spraying device 15 performing spraying toward the mold 101 before mold closing in each molding cycle. The control device 5 controls the operation of the cooling part 13 based on a temperature difference between a first temperature D1 detected by the temperature sensor 59 before spraying and a second temperature D2 detected by the temperature sensor 59 after spraying in the molding cycle in which the first temperature D1 was detected.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a molding machine and a spray device used in the molding machine. The molding machine is a machine that fills a mold cavity with a molding material to obtain a molded product, such as a die-casting machine or an injection molding machine. The spray device sprays, for example, a mold release agent into the mold. [Background technology]

[0002] It is known that when a molding material is filled into a mold cavity to obtain a molded product, the temperature of the mold affects the quality of the molded product (for example, Patent Documents 1 to 3 below). It is also known that a mold release agent sprayed onto the mold affects the temperature of the mold (Patent Documents 1 and 2).

[0003] Patent Document 1 discloses a molding machine that sprays at multiple locations on the mold. This molding machine has temperature sensors at multiple locations on the mold, and controls the amount of release agent sprayed at multiple locations on the mold based on the detected values ​​of the multiple temperature sensors so that the temperature of the mold is uniform. This molding machine also detects the temperature before spraying in each molding cycle, compares the temperature detected in the previous molding cycle with the temperature detected in the current molding cycle, and determines the amount of release agent to be sprayed in the current molding cycle.

[0004] Patent Document 2 discloses a spray system that sprays by sequentially moving a spray head to multiple blocks that divide the inner surface of a mold. This system uses a non-contact thermometer mounted on the spray head to detect the temperature of the block immediately before spraying, and sets the spray discharge pattern based on that temperature.

[0005] Patent Document 3 discloses a detection device that detects signs of temperature abnormalities based on an image of the mold temperature obtained by thermography. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 10-193070 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-150617 [Patent Document 3] Japanese Patent Application Publication No. 2019-84556 Summary of the Invention [Problem to be solved by the invention]

[0007] With the techniques of Patent Documents 1 and 2, it can be difficult to achieve a target mold temperature. For example, even if the amount of release agent to be sprayed is set by multiplying the temperature difference between the target mold temperature and the measured mold temperature by a predetermined coefficient, the mold temperature will not reach the target value unless the coefficient is set appropriately. Furthermore, the appropriate value of the coefficient may change due to, for example, changes in the state of the cooling equipment (e.g., clogging of the flow path or pressure fluctuations) or changes in the ambient temperature. Therefore, it is desirable to provide a molding machine and a spray device that can improve the accuracy of mold temperature control. [Means for solving the problem]

[0008] A molding machine according to one embodiment of the present disclosure is a die-casting machine that repeats molding cycles, and includes a machine main body that sequentially performs mold closing, injection, and mold opening in each molding cycle, a cooling unit that cools the mold in each molding cycle, and a control device that controls the cooling unit based on a signal from a sensor that detects the temperature of the mold, wherein the cooling unit includes a spray device that sprays toward the mold before it is closed in each molding cycle, and the control device controls the operation of the cooling unit based on the temperature difference between a first temperature detected by the sensor before the spray and a second temperature detected after the spray in the molding cycle in which the first temperature was detected.

[0009] A spray device according to one aspect of the present disclosure comprises a spray device main body that sprays toward the mold before it is closed during each molding cycle when a molding cycle including mold closing, injection, and mold opening is repeated, and a spray control unit that controls the spray device main body based on a signal from a sensor that detects the temperature of the mold, and the spray control unit controls the operation of the spray device main body during the subsequent molding cycle based on the temperature difference between a first temperature detected by the sensor before the spraying and a second temperature detected after the spraying during the molding cycle in which the first temperature was detected. [Effects of the Invention]

[0010] According to the above configuration, it is possible to improve the accuracy in controlling the temperature of the mold. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a side view showing a configuration of a die casting machine according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a schematic diagram showing an example of the configuration of a cooling section of the die-casting machine of FIG. 1. [Figure 3] 1. FIG. 4 is a schematic diagram showing another example of the configuration of the cooling section of the die-casting machine of FIG. [Figure 4] 2 is a flowchart for explaining the operation of the die casting machine of FIG. 1. [Figure 5] 5(a) and 5(b) are timing charts showing an example and another example of a method for adjusting the amount of refrigerant supplied. [Figure 6] 6(a) and 6(b) are timing charts showing an example and another example of a method for adjusting the supply amount of the release agent. DETAILED DESCRIPTION OF THE INVENTION

[0012] In the following, first, an overview of a die-casting machine according to an embodiment of the present disclosure will be described, and then the details of the die-casting machine will be described.

[0013] (Die casting machine overview) Fig. 1 is a side view (partially including a cross-sectional view) showing the configuration of a die-casting machine 1 according to an embodiment of the present disclosure. For convenience, Fig. 1 is illustrated with a Cartesian coordinate system xyz. The z direction is the vertical direction, and the +z side is upward.

[0014] The die-casting machine 1 holds a die 101. The die 101 includes, for example, a fixed die 103 and a movable die 105. As indicated by the two-dot chain line in FIG. 1 , the die-casting machine 1 brings the movable die 105 close to the fixed die 103 and brings them into contact (performs die closing). This forms a cavity Ca between the fixed die 103 and the movable die 105, having a shape similar to that of a molded product (in other words, a die-cast product or a finished product). The die-casting machine 1, for example, fills the cavity Ca with an unhardened metal material (performs injection). The metal material filled in the cavity Ca solidifies as heat is absorbed by the die 101, thereby producing a molded product. Thereafter, the die-casting machine 1 separates the movable die 105 from the fixed die 103 (performs die opening) to remove the molded product. The die-casting machine 1 repeats a molding cycle in which, for example, die closing, injection, and die opening are performed in sequence as described above.

[0015] In each molding cycle, before the mold is closed, a release agent or the like is sprayed onto the opposing surfaces of the fixed mold 103 and the movable mold 105. The release agent, for example, forms a coating on the surface of the mold 101 and is present between the surface of the mold 101 and the metal material filled into the mold 101. The release agent contributes to reducing the likelihood of seizure, in which the metal material adheres to the mold 101, and to reducing the resistance (mold release resistance) when a molded product is peeled off from the mold 101. The release agent can also contribute to cooling the mold 101, whose temperature has risen in the previous molding cycle.

[0016] FIG. 4 is a flowchart for explaining the operation of the die-casting machine 1.

[0017] As described above, the die-casting machine 1 repeatedly performs molding cycles MC. In each molding cycle MC, for example, spraying (step ST1), mold closing (step ST2), injection (step ST3), and mold opening (step ST4) are performed in that order. The mold 101 is cooled at an appropriate time during the molding cycle MC by a cooling unit 13 (described later). For example, the cooling operation by the cooling unit 13 includes spraying. Also, cooling operations other than spraying may be performed during the spraying period.

[0018] In this embodiment, the die-casting machine 1 detects, for example, the temperature of the mold 101 before spraying and the temperature of the mold 101 after spraying in each molding cycle (steps ST11 and ST12). The former temperature may be referred to as the "first temperature" or "first temperature D1," and the latter temperature may be referred to as the "second temperature" or "second temperature D2."

[0019] The difference between the first temperature and the second temperature in one (same) molding cycle serves as an index value for quantitatively evaluating the cooling effect of the cooling unit 13 on the mold 101. Therefore, the die-casting machine 1 controls the operation of the cooling unit 13 based on the difference between the first temperature and the second temperature. In Fig. 4, as shown by the arrows extending from the first temperature D1 and the second temperature D2 and the control command (command D3), an example is shown in which the spray in the molding cycle following the molding cycle in which these temperatures were detected is controlled based on the first temperature and the second temperature.

[0020] As described above, in this embodiment, the die-casting machine 1 controls the operation of the cooling unit 13 in a subsequent cycle (e.g., the next molding cycle) based on the difference between the first temperature and the second temperature within the same molding cycle. Therefore, for example, the cooling effect of the cooling unit 13 can be quantitatively grasped, and the operating state of the cooling unit 13 required to achieve a target temperature can be identified. From another perspective, the operating state of the cooling unit 13 can be, for example, the operating amount or manipulated variable of the cooling unit 13 (from another perspective, the value of a parameter such as gain), or a physical quantity related to cooling. In this way, the accuracy of temperature control of the mold 101 is improved. Generally, the temperature of the mold 101 decreases more significantly when spraying is performed. Therefore, by controlling the operation of the cooling unit 13 based on the first temperature and the second temperature measured before and after spraying, the accuracy of temperature control of the mold 101 is further improved.

[0021] (Die casting machine details) Here, the die casting machine 1 will be roughly described in the following order. Overall configuration of die-casting machine 1 (Fig. 1) A cooling section 13 (FIG. 2 or FIG. 3) for cooling the mold 101 A temperature sensor 59 (FIG. 2 or 3) for detecting the temperature of the mold 101 Control of the operation of the cooling unit 13 based on the first temperature D1 and the second temperature D2 (FIGS. 4 to 6(b)) Summary of embodiments

[0022] (Overall configuration of die casting machine) As described above, the die-casting machine 1 shown in FIG. 1 injects an unhardened metal material into the space (including the cavity Ca) defined by the die 101. The unhardened state is, for example, a liquid state or a solid-liquid coexistence state. The solid-liquid coexistence state is a semi-solidified state in which solidification has progressed from a liquid state, or a semi-molten state in which melting has progressed from a solid state. The metal is, for example, an aluminum alloy, a zinc alloy, or a magnesium alloy. Note that, hereinafter, some expressions will be made assuming that the unhardened metal material is a molten metal (liquid metal material).

[0023] As described above, the mold 101 includes, for example, the fixed mold 103 and the movable mold 105. In the drawings of the present disclosure, for convenience, the cross section of the fixed mold 103 or the movable mold 105 is shown with one type of hatching. However, each mold may be a direct-carving type formed as a single unit, or may be a nested type formed by fitting a nest into a main mold. Furthermore, the mold 101 may have a fixed core fixed to the fixed mold 103 or the movable mold 105, and / or a movable core sandwiched between the fixed mold 103 and the movable mold 105.

[0024] The die-casting machine 1 has a cooling section 13 that cools the die 101. The cooling section 13 includes a spray device 15 that sprays the die 101.

[0025] Of the parts of the die-casting machine 1 that perform mechanical operations, the parts excluding the cooling section 13 are referred to as the machine body 3. The machine body 3 has, for example, a mold clamping device 7 that opens, closes, and clamps the mold 101, an injection device 9 that injects molten metal into the mold 101, and an extrusion device 11 that extrudes the die-cast product from a fixed mold 103 or a movable mold 105 (movable mold 105 in FIG. 1).

[0026] The die-casting machine 1 also has a control device 5 (see FIG. 2 or FIG. 3, which will be described later) that controls the machine body 3 and the cooling unit 13. The control device 5 may be regarded as a component separate from the machine body 3, the cooling unit 13, or the spray device 15, or may be regarded as a component of the machine body 3, the cooling unit 13, or the spray device 15. In the description of the present disclosure, for convenience, the former and latter expressions may be used.

[0027] The configuration and operation of the machine body 3 (for example, the mold clamping device 7, the injection device 9, and the extrusion device 11) may be variously configured and may be of a known configuration. In addition, the cooling unit 13 and the spray device 15 may also be variously configured and may be of a known configuration, except for the parts related to their control.

[0028] For example, the mold clamping unit 7 may use a toggle mechanism to open / close and clamp the mold (as shown in the example of FIG. 1), or may not have a toggle mechanism. In the latter embodiment, mold opening / closing and mold clamping may be performed by separate drive sources. Furthermore, for example, the drive system of the mold clamping unit 7 may be an electric system, a hydraulic system (hydraulic system), or a hybrid system that combines these.

[0029] The injection device 9 may be, for example, for a cold chamber machine (example of FIG. 1), for a hot chamber machine, or a hybrid type that combines both. Also, for example, the drive system of the injection device 9 may be an electric system, a hydraulic system (hydraulic system), or a hybrid system that combines these systems.

[0030] The extrusion device 11 may be, for example, one that extrudes a molded product from a movable mold 105 (the example in FIG. 1), or one that extrudes a molded product from a fixed mold 103. Furthermore, for example, the extrusion device 11 may be one that has an electric or hydraulic (hydraulic) drive source, or one that uses mold opening by the mold clamping device 7 (one that does not have a drive source).

[0031] The control device 5 may be configured, for example, by a computer. The computer may include, for example, a central processing unit (CPU), read only memory (ROM), random access memory (RAM), and an external storage device, although not shown. The CPU executes programs stored in the ROM and / or the external storage device to implement various functional units (described below) that perform control, etc. The control device 5 may also include a logic circuit that performs only certain processes.

[0032] (Cooling section configuration) Fig. 2 is a schematic diagram showing a cooling section 13A as a specific example of the cooling section 13. Fig. 3 is a schematic diagram showing a cooling section 13B as another specific example of the cooling section 13.

[0033] In the following description, the reference numerals of the components of the cooling unit 13A may be given the letter A, and the reference numerals of the components of the cooling unit 13B may be given the letter B. In addition, the components with the reference numerals A and B may be omitted and the components may be referred to without distinction (see also FIG. 1 for the reference numerals in this case).

[0034] The cooling unit 13 has, for example, a spray device 15 (15A or 15B) and also an internal cooling device 17 (17A or 17B) that adjusts the flow of a coolant (e.g., water) supplied to a flow path 107 provided in the mold 101 (fixed mold 103 and / or movable mold 105). The cooling unit 13 may be considered to have the control device 5 (or a part thereof) as described above.

[0035] Here, the components of the cooling unit 13 will be roughly described in the following order. Spray device 15 Flow path 107 and internal cooling device 17 A control unit that controls the cooling unit 13

[0036] (spray device) The spray device 15 sprays, for example, a liquid in the form of a mist onto the mold 101. The liquid is, for example, a release agent and / or water. In the following description, for convenience, only a release agent will be taken as an example of the liquid. The release agent may be any of various known types, for example, a water-soluble or oil-based one. The cooling effect of a water-soluble release agent (i.e., a release agent containing water) is greater than that of an oil-based release agent. The release agent may be sprayed as is, or may be diluted with water or the like and then sprayed, or may be diluted with water or the like that was sprayed together with the original liquid after spraying. The spray device 15 may not recover the sprayed release agent, or may recover and reuse it.

[0037] As described above, the spray device 15 may have various configurations, excluding the configuration related to its control, and may have, for example, a known configuration. For example, the spray device 15 has one or more nozzles 19 (19A or 19B) (multiple in the illustrated example) that spray the release agent toward the mold 101. The spray device 15 may be one in which the nozzle 19 is inserted and removed into the space between the fixed mold 103 and the movable mold 105 when the molds are open (examples of FIGS. 2 and 3), or the nozzle 19 may be fixed outside the space. For convenience, the former type will be referred to as an "insertion type."

[0038] The surface of the fixed mold 103 or the movable mold 105 to which the release agent is to be applied (for example, the surface that will become the inner surface of the cavity Ca) is referred to as the surface to be coated 109. The insertion type spray device 15 may, for example, be one that applies the release agent to the entire surface to be coated 109 from multiple nozzles 19 that are stopped at predetermined positions in the space between the fixed mold 103 and the movable mold 105 that have been opened, or one that sprays the release agent onto the entire surface to be coated 109 by sequentially moving one or more nozzles 19 onto multiple regions that have been divided into the surface to be coated 109. In the latter embodiment, the movement of the nozzles 19 and / or the spraying of the release agent may be performed continuously or intermittently.

[0039] The spray device 15 illustrated in Figures 1 to 3 is an insertion type, and has, for example, a head 21 (21A or 21B) including a plurality of nozzles 19, and a driving device 23 (23A or 23B) that moves the head 21. Furthermore, as shown in Figures 2 and 3, the spray device 15 has a supply device 27 that supplies a release agent to the head 21 (in other words, the nozzles 19).

[0040] The head 21 has, for example, a plurality of nozzles 19, as well as a base 25 (25A or 25B) that holds the plurality of nozzles 19. The base 25 is held by, for example, a drive device 23. Furthermore, although not particularly shown, the base 25 has a flow path therein, and the flow path connects the supply device 27 and the nozzles 19.

[0041] 2, the head 21A is exemplified as having a plurality of nozzles 19A, each of which is formed by a relatively long pipe (e.g., copper pipe). Each nozzle 19A can be bent to cause plastic deformation, for example, to adjust the position and orientation of its tip (discharge port). The plurality of nozzles 19A extend, for example, from one surface (the lower surface in the illustrated example) of the base 25A. Note that in FIG. 1, the head 21A is exemplified as the head 21.

[0042] 3, the head 21B has a plurality of relatively short nozzles 19B. The plurality of nozzles 19B are provided on two surfaces of the base 25B facing the fixed mold 103 or the movable mold 105, and eject the release agent generally from the two surfaces toward the fixed mold 103 or the movable mold 105. The ejection direction of the plurality of nozzles 19B may be changeable by changing the orientation with respect to the base 25B, or may not be changeable in this way.

[0043] The multiple nozzles 19 (19A or 19B) may have the same or different amounts of release agent discharged. The multiple nozzles 19 may have the same or different amounts of release agent discharged, respectively. The nozzles 19 may have the same or different amounts of release agent discharged, respectively. The nozzles 19, the base 25, or the supply device 27 may have a configuration for differentiating the discharge amounts from each other or for individually controlling the discharge amounts from each other.

[0044] Nozzle 19 (19A or 19B) may or may not be detachable from base 25. Although not particularly shown, base 25 (25A and 25B) may or may not have a configuration including a first part that is held by drive device 23 and connected to supply device 27, and a second part that holds nozzle 19 and is detachable from the first part.

[0045] 2 and 3 are schematic diagrams, and therefore the release agent is simultaneously applied to only a portion of the surface 109 of the mold 101. However, the heads 21A and 21B may be used in a manner to spray the release agent onto the entire surface 109 of the mold 101 at a predetermined position, or may be used in a manner to spray the release agent onto multiple regions obtained by dividing the surface 109 in turn.

[0046] The driving device 23 is capable of moving the head 21 at least in a direction (up and down in the illustrated example) of inserting and removing the head 21 between the fixed mold 103 and the movable mold 105. The driving device 23 may also be capable of moving the head 21 in a direction facing the fixed mold 103 and the movable mold 105, or may be capable of moving the head 21 in a direction intersecting the above-mentioned direction of insertion and removal and the facing direction (for example, the x direction in FIG. 1).

[0047] The specific configuration of the drive unit 23 for realizing the movement of the head 21 as described above is arbitrary. For example, the drive unit 23 may be a vertical articulated robot having a rotating arm (as shown in the example of FIG. 1), or may be a Cartesian coordinate robot that translates a slide axis. The drive system of the drive unit 23 is, for example, an electric system, and in FIGS. 2 and 3, an electric motor (reference number omitted) is schematically shown as the drive unit 23. The drive unit 23 is installed, for example, on the upper surface of a die plate (reference number omitted) that holds the fixed mold 103 of the mold clamping unit 7.

[0048] The supply device 27 supplies air to the head 21 (base 25) in parallel with the release agent, for example. A flow path for the release agent and a flow path for the air are formed inside the base 25. The release agent and air are mixed and atomized at an appropriate position and sprayed onto the surface 109 of the mold 101 to be coated. The release agent and air may be mixed inside the base 25, inside the nozzle 19, or outside the nozzle 19.

[0049] The supply device 27 may be capable of supplying only air to the head 21, thereby causing only air to be sprayed from the nozzle 19 toward the mold 101. In other words, the spray device 15 may be capable of blowing air. Air blowing may be used, for example, to clean the mold 101 before spraying the mold release agent and / or to remove moisture after spraying the mold release agent.

[0050] The supply device 27 may have any specific configuration for supplying the release agent as described above. In the example shown in the figure, the supply device 27 has the following components: a tank 29 that holds the release agent; a pump 31 that sends air into the tank 29 to pressurize the release agent in the tank 29 and send it out; and a valve 33 that controls the flow of the released release agent.

[0051] The valve 33 may be a valve that simply allows or prohibits the flow of the release agent, or it may be a flow control valve that can control the flow rate of the release agent. The flow control valve may or may not be a pressure-compensated flow control valve that can maintain a desired flow rate regardless of pressure fluctuations, and may or may not be a servo valve.

[0052] Unlike the illustrated example, a pump may be provided to suck and discharge the release agent from the tank 29. Two or more valves may be provided at appropriate positions. A control valve may be provided to control the pressure of the release agent. In addition to or instead of controlling the valve 33, the supply or absence or flow rate of the release agent may be controlled by controlling the pump. In this case, the valve 33 may be omitted.

[0053] The supply device 27 may have sensors for detecting various physical quantities related to the release agent. For example, the supply device 27 may have a sensor 35 for detecting the flow rate of the release agent, a sensor (not shown) for detecting the pressure of the release agent, a sensor (not shown) for detecting the temperature of the release agent, and / or a sensor (not shown) for detecting the concentration of the release agent. For example, in an embodiment in which the valve 33 is a flow control valve, the sensor 35 may be used for feedback control of the flow rate.

[0054] The specific configuration for supplying air in the supply device 27 is also arbitrary. In the example shown, the supply device 27 has the following components: a pump 37 for delivering air; and a valve 39 for controlling the flow of the delivered air. The supply device 27 may also have an appropriate sensor, such as a sensor 41 for detecting the pressure or flow rate of the air.

[0055] The valve 39 may simply allow or prohibit the flow of air, or may be capable of controlling the pressure or flow rate of air. Unlike the illustrated example, two or more valves may be provided at appropriate positions. In addition to or instead of controlling the valve 39, the presence or absence of air supply or the pressure (or flow rate) may be controlled by controlling the pump 37. In this case, the valve 39 may be omitted.

[0056] (flow path and internal cooling device) 2 and 3, for ease of illustration, only the flow path 107 provided in the movable mold 105 is shown schematically. In reality, the flow path 107 may also be provided in the fixed mold 103. Furthermore, the internal cooling device 17 may supply a refrigerant to the flow path 107 of the fixed mold 103 and the flow path 107 of the movable mold 105.

[0057] The coolant may be liquid, gas, or mist, and may change state as heat is absorbed from the mold 101. The components of the coolant are also arbitrary. An example of a liquid coolant is water. In the following, some expressions will be used assuming that the coolant is water (liquid). In the following, the water supplied to the mold 101 will be simply referred to as cooling water, without any modification such as "supplied to the mold 101."

[0058] The specific shape and dimensions of the flow path 107 are arbitrary. For example, the flow path 107 may be a so-called direct-current type, a circulation type, a jet type, or a combination thereof. In the direct-current type, for example, multiple flow paths 107 extending in one direction (for example, linearly) through the mold (103 or 105) are provided in parallel, contributing to cooling the entire mold. In the circulation type, for example, the flow path 107 extends so as to surround a local portion of the mold, contributing to cooling the local portion. In the jet type, for example, the flow path 107 includes a space within a local portion of the mold (for example, a fixed core) and a pipe inserted in the space, and cooling water flowing out from the tip of the pipe into the space flows toward the base of the pipe, thereby cooling the local portion.

[0059] In an embodiment in which a plurality of flow paths 107 are provided, the shapes and dimensions of the plurality of flow paths 107 may be the same as or different from one another. Furthermore, the permission and prohibition of the flow of cooling water and / or the flow rate of two or more and / or all of the plurality of flow paths 107 may be controlled together, or may be controlled separately. Separate control may be achieved, for example, by providing a plurality of valves 45 (described below) in the internal cooling device 17.

[0060] The internal cooling device 17 may supply cooling water to the mold 101 continuously throughout the entire period of each molding cycle, or may supply cooling water to the mold 101 intermittently during each molding cycle. In the latter embodiment, the internal cooling device 17 may or may not supply air to the mold 101 during periods when cooling water is not being supplied. The air may, for example, contribute to purging the cooling water in the flow path 107. For convenience, a description of the supply of air will be omitted below. The internal cooling device 17 may not recover the cooling water supplied to the mold 101 (example of FIG. 2), or may recover the cooling water supplied to the mold 101 (example of FIG. 3). In either case, the specific configuration thereof is arbitrary.

[0061] The internal cooling device 17A illustrated in Fig. 2 has a pump 43 that delivers cooling water and a valve 45 that controls the flow of the delivered cooling water. The pump 43, for example, sucks cooling water stored in a tank (not shown) and delivers it to the flow path 107. Note that the pump 43 may be a factory facility that also supplies cooling water to other machines (for example, other die-casting machines). From another perspective, the internal cooling device 17A does not necessarily have to have the pump 43.

[0062] In the internal cooling device 17A, the valve 45 may be a valve that simply allows or prohibits the flow of cooling water, or may be a flow control valve that can control the flow rate of cooling water. The flow control valve may or may not be a pressure-compensated flow control valve that can maintain a desired flow rate regardless of pressure fluctuations, and may or may not be a servo valve.

[0063] The internal cooling device 17A may have sensors at appropriate positions for detecting various physical quantities related to the cooling water. For example, the internal cooling device 17 may have a sensor 47 for detecting the flow rate of the cooling water, a sensor (not shown) for detecting the pressure of the cooling water, and / or a sensor (not shown) for detecting the temperature of the cooling water, located upstream and / or downstream of the flow path 107. For example, in an embodiment in which the valve 45 is a flow control valve, the sensor 47 may be used for feedback control of the flow rate.

[0064] 3 has the same configuration as the internal cooling device 17A, and in addition has a recovery section 51 that recovers the cooling water that has flowed out of the mold 101. A pump 43 sends the cooling water recovered in the recovery section 51 to the mold 101. Except for this point, the above description of the internal cooling device 17A may be applied to the internal cooling device 17B.

[0065] The recovery unit 51 may include, for example, one or more tanks for storing cooling water and a device for cooling the cooling water (e.g., a heat pump), although these are not particularly shown. Part or all of the recovery unit 51 may be factory equipment that also supplies cooling water to other machines (e.g., other die-casting machines). From another perspective, the internal cooling device 17B may not include the recovery unit 51.

[0066] 3, the internal cooling device 17 (17A or 17B) may have a pump 49 that generates a negative pressure in the flow path 107 in addition to or instead of the pump 43 that sends cooling water to the flow path 107 of the mold 101. The negative pressure may then cause the cooling water to flow inside the mold 101. In this case, the likelihood of the cooling water leaking out of the flow path 107 is reduced.

[0067] Although not specifically shown, the internal cooling device 17 (17A or 17B) may have a valve that controls the flow on the outlet side of the flow path 107 in addition to or instead of the valve 45 that controls the flow on the inlet side of the flow path 107. This valve may then control whether or not cooling water is supplied, and the flow rate.

[0068] (Control unit that controls the cooling unit) 2 and 3, the control device 5 has, for example, a main body control unit 53 that controls the machine main body 3, a spray control unit 55 that controls the spray device 15, and an internal cooling control unit 57 that controls the internal cooling device 17. These functional units are configured, for example, by the CPU executing a program, as described above.

[0069] The main body control unit 53, spray control unit 55, and internal cooling control unit 57 may be separated from one another in terms of hardware, or may be integrated into one unit. As an example of the former, the main body control unit 53 and internal cooling control unit 57 may be configured by hardware distributed together with the machine main body 3, while the spray control unit 55 may be configured by hardware distributed together with the spray device 15. In this case, the spray control unit 55 may control the operation of the spray device 15 based on, for example, a signal received from the main body control unit 53 via a cable (not shown).

[0070] (Temperature sensor) 2 or 3 (59A or 59B), as will be understood from the above description, is used to detect, for example, the temperature of the mold 101 before spraying and the temperature of the mold 101 after spraying. The temperature sensor 59 may be regarded as a part of the die-casting machine 1, the cooling section 13, the spray device 15, or the internal cooling control section 57, or may be regarded as a component separate from these.

[0071] The temperature sensor 59 may be configured in various ways, for example, it may be similar to a known way. For example, the temperature sensor may be a contact type (for example, a thermocouple, a thermistor, or a resistance temperature detector) or a non-contact type (for example, a radiation thermometer). Furthermore, for example, the temperature sensor may be one that directly detects the temperature of the mold 101, or one that detects a physical quantity that is highly correlated with the temperature of the mold 101 (for example, the temperature of the cooling water flowing through the flow path 107). The temperature sensor may be only a transducer, or may be one that includes a transducer and a circuit for performing processing such as amplification.

[0072] 2 illustrates a contact-type temperature sensor 59A as the temperature sensor 59. For ease of illustration, only the temperature sensor 59A that detects the temperature of the movable mold 105 is illustrated in FIG. 2, but it goes without saying that a temperature sensor 59A that detects the temperature of the fixed mold 103 may also be provided.

[0073] The temperature sensor 59A may be positioned arbitrarily. For example, when the mold (103 or 105) is divided into thirds in the x, y, or z directions, the temperature sensor 59A may be positioned in any of these areas. The detected value of the temperature sensor 59A may be used as is, or may be corrected appropriately before use. In the description of this disclosure, the corrected value is also considered to be a type of detected value. The same applies to the example of FIG. 3 described later.

[0074] Although not particularly shown, two or more temperature sensors 59A may be provided in one mold (103 or 105). The two or more temperature sensors 59A may be arranged at different positions when viewed in the opposing direction of the fixed mold 103 and the movable mold 105, or may be arranged at different positions when viewed in a direction perpendicular to the opposing direction.

[0075] The detection values ​​of two or more temperature sensors 59A may be used to determine a representative value of the temperature of the entire mold (103 or 105) or the entire surface 109 to be coated, or may be used to determine the temperature distribution of the mold or surface 109 to be coated. Examples of representative values ​​include an average value (arithmetic mean) and a weighted average value. In determining the temperature distribution, the detection values ​​of each temperature sensor may be used, or values ​​obtained by interpolation may be used in addition to or instead of the detection values ​​themselves. In the description of this disclosure, values ​​obtained by interpolation are also considered to be a type of detection value.

[0076] 3 illustrates a non-contact temperature sensor 59B as the temperature sensor 59. For ease of illustration, only the temperature sensor 59B that detects the temperature of the movable mold 105 is illustrated in FIG. 3, but it goes without saying that a temperature sensor 59B that detects the temperature of the fixed mold 103 may also be provided.

[0077] More specifically, the temperature sensor 59B is, for example, a thermograph that acquires an image of the temperature distribution of the surface 109 to be coated. The temperature sensor 59B may acquire the temperature distribution of the entire surface 109 to be coated, or may acquire the temperature distribution of a partial region of the surface 109 to be coated. Although not particularly shown, a plurality of temperature sensors 59B (or imaging units thereof) that capture images of different regions of the surface 109 to be coated may be provided, thereby acquiring the temperature distribution of the entire surface 109 to be coated.

[0078] The temperature sensor 59B may be positioned at any location. For example, the temperature sensor 59B may be positioned above (in the illustrated example), to the side, or below the mold (103 or 105). The imaging unit of the temperature sensor 59B may be fixed, or the position and / or orientation may be changeable. In other words, the temperature sensor 59B may or may not be capable of mechanical scanning.

[0079] The temperature distribution obtained by the temperature sensor 59B may be used to identify a representative value of the temperature on the surface 109, or may be used to identify a representative value of the temperature for each of the regions into which the surface 109 is divided, or may be used to extract the temperature at a specific position on the surface 109. Examples of the representative value include an average value (arithmetic average) and a weighted average value.

[0080] (Control of operation of cooling unit based on first temperature and second temperature) As described above, the die casting machine 1 (or, from another perspective, the control device 5, the spray control unit 55, or the internal cooling control unit 57) controls the operation of the cooling unit 13 thereafter (for example, in the next molding cycle) based on the difference between the first temperature and the second temperature within the same molding cycle. More specifically, for example, the control device 5 determines the operation amount of the cooling unit 13 required to obtain the target temperature based on the difference between the first temperature and the second temperature, and controls the cooling unit 13. Here, the control of the operation of the cooling unit based on the first temperature and the second temperature will be roughly described in the following order. Overall control of the cooling unit operation based on the first and second temperatures (Figure 4) Example of how to calculate the manipulated variable based on the first and second temperatures Specific examples of the operation of the cooling unit controlled based on the first temperature and the second temperature (FIGS. 5(a) to 6(b))

[0081] (Overall control of the operation of the cooling unit based on the first temperature and the second temperature) The outline of Figure 4 has already been described. More details are as follows.

[0082] The main body control unit 53 controls the mold clamping unit 7 to close the molds (step ST2). Although not shown, after the molds are closed (for example, after the movable mold 105 comes into contact with the fixed mold 103), the main body control unit 53 controls the mold clamping unit 7 to clamp the movable mold 105 and the fixed mold 103 together. Also, although not shown, the main body control unit 53 controls, for example, a melt supply unit (not shown) to supply molten metal to the injection unit 9. Once the supply of molten metal is complete, the main body control unit 53 controls the injection unit 9 to inject the molten metal into the cavity Ca (step ST3). Once the injected molten metal solidifies, the main body control unit 53 controls the mold clamping unit 7 to open the molds (step ST4). Although not shown, during or after mold opening, the main body control unit 53 controls the extrusion unit 11 to extrude the molded product. The main body control unit 53 repeats this control (molding cycle MC).

[0083] The spray control unit 55 controls the spray device 15 to spray a release agent at an appropriate time between after the mold is opened (usually after the molded product is extruded) and before the mold is closed (usually before the mold closing process begins) (step ST1). Although not specifically shown, the spray control unit 55 may sequentially spray release agents (liquids) with different components. In such an embodiment, the spray that serves as the basis for detecting the first temperature D1 and the second temperature D2 may be a spray of any one type of release agent or may be a spray of all types of release agents. As already mentioned, the spray control unit 55 may also control the spray device 15 to clean the mold 101 with air blowing before spraying the release agent, or to remove moisture with air blowing after spraying the release agent.

[0084] In addition, the molding cycle MC may be defined such that any point in any step of a plurality of steps performed sequentially is the reference point (the end point of the previous molding cycle MC and the start point of a new molding cycle MC). In the explanation of the present disclosure, for convenience, the molding cycle MC may be expressed as being the reference point at the time when mold opening in step ST4 (or the extrusion step (not shown) for extruding the molded product) is completed.

[0085] As described above, the control device 5 (from another perspective, the machine main body 3, the spray control unit 55, or the internal cooling control unit 57; the same applies below) acquires the first temperature D1 and the second temperature D2 detected by the temperature sensor 59 (steps ST11 and ST12). Note that in the explanation of the present disclosure, there is no particular distinction between the time when the temperature is measured by the temperature sensor 59 and the time when the control device 5 acquires information about the measured temperature from the temperature sensor 59.

[0086] As described above, the measurement time of the first temperature D1 is before spraying (step ST1). Whether or not it is "before spraying" may be reasonably determined in light of the above-described operation of this embodiment. For example, typically, the measurement time of the first temperature D1 may be before spraying begins. In this case, the measurement time of the first temperature D1 may be immediately before spraying begins, or may be a time a certain length of time before the start of spraying. Examples of the latter include, for example, when mold opening begins, immediately after mold opening, or immediately after extrusion of the molded product. Furthermore, other than typical examples, the start of spraying or immediately after spraying begins may be mentioned. In other words, the measurement time of the first temperature D1 may be at least a part of the period during which spraying is performed, rather than before the entire period during which spraying is performed.

[0087] As described above, the measurement time of the second temperature D2 is after the spraying (step ST1). Whether or not it is "after the spraying" may be reasonably determined in light of the above-described operation of this embodiment, similar to the "before the spraying" determination. For example, the measurement time of the second temperature D2 may typically be after the completion of the spraying. In this case, the measurement time of the second temperature D2 may be immediately after the completion of the spraying, or may be a time a certain length of time later than the completion of the spraying. Examples of the latter include the start of mold closing, the completion of mold closing, the start of mold clamping, the completion of mold clamping, or just before the start of injection. Furthermore, other than the typical examples, the completion of the spraying or just before the completion of the spraying may be mentioned. In other words, the measurement time of the second temperature D2 may be after at least a part of the period during which the spraying is performed (but after the measurement time of the first temperature D1).

[0088] As described above, "before spraying" and "after spraying" may refer to before and after at least a portion of the period during which spraying is performed. From another perspective, it is sufficient that at least a portion of the period during which spraying is performed is included in the period from the time point at which the first temperature D1 is measured to the time point at which the second temperature D2 is measured. In this case, the portion may be, for example, 30% or more, 50% or more, or 80% or more of the entire period during which spraying is performed, and may be close to the start of spraying, close to the end of spraying, or somewhere in between.

[0089] As can be seen from the above, the period from the time when the first temperature D1 is measured to the time when the second temperature D2 is measured may include a period during which spraying is not being performed (a period before the start of spraying and / or a period after the completion of spraying). In this case, the proportion of the period during which spraying is being performed (at least a portion of the period from the start to the completion of spraying) within the period from the time when the first temperature D1 is measured to the time when the second temperature D2 is measured may be any proportion. For example, this proportion may be 10% or more, 30% or more, 50% or more, or 80% or more.

[0090] As described below, the period during which spraying is performed in each molding cycle may be changed. In such an embodiment, the time point at which the first temperature D1 and / or the second temperature D2 are measured may or may not be changed.

[0091] 4, the operation of the spray device 15 is controlled based on the difference between the first temperature D1 and the second temperature D2. However, in addition to or instead of the operation of the spray device 15, the operation of the internal cooling device 17 (or the operation of another cooling means) may be controlled based on the difference between the first temperature D1 and the second temperature D2. Just to be clear, in an embodiment in which cooling by two or more cooling means is performed simultaneously (e.g., during spraying), the operation of one cooling means may be controlled based on the difference between the first temperature D1 and the second temperature D2, and the operation of the other cooling means may not be controlled based on the difference between the first temperature D1 and the second temperature D2.

[0092] 4, the first temperature D1 and the second temperature D2 are detected for each molding cycle (in other words, for all molding cycles). The first temperature D1 and the second temperature D2 detected in each molding cycle are used to control the operation of the cooling unit 13 in the next molding cycle. In the description of this embodiment, this mode is basically taken as an example.

[0093] However, unlike the illustrated example, for example, the detection of the first temperature D1 and the second temperature D2 may be performed every two or more predetermined number of molding cycles (in only one of the predetermined number of molding cycles), or may be performed irregularly. An example of the latter is a mode in which detection is performed when some kind of abnormality is detected. Then, for example, the first temperature D1 and the second temperature D2 detected every predetermined number of times or irregularly may be used for multiple subsequent molding cycles.

[0094] Furthermore, for example, unlike the illustrated example, the operation of the cooling unit 13 in the subsequent molding cycle may be controlled based on the first temperature D1 and the second temperature D2 detected in each of multiple molding cycles. For example, average values ​​(moving average values) of the first temperature D1 and the second temperature D2 in the multiple molding cycles may be calculated based on the first temperature D1 and the second temperature D2 detected in each of the multiple molding cycles. Then, the operation of the cooling unit 13 in the subsequent molding cycle may be controlled based on the average values. In this case, for example, the influence of a specific error in the detected temperature occurring in any one molding cycle on the operation of the cooling unit 13 is reduced.

[0095] Furthermore, for example, control of the operation of the cooling unit 13 based on the difference between the first temperature D1 and the second temperature D2 may be started without waiting for the start of the next molding cycle. From another perspective, a change in the operation of the cooling unit 13 based on the difference between the first temperature D1 and the second temperature D2 may occur within the molding cycle in which the first temperature D1 and the second temperature D2 are detected. In this case, the operation of the cooling unit 13 controlled based on the difference between the first temperature D1 and the second temperature D2 may affect the difference between the first temperature D1 and the second temperature D2 in the next molding cycle. For example, the operation (or, from another perspective, the manipulated variable) changed based on the difference between the first temperature D1 and the second temperature D2 may be maintained until the spray period of the next molding cycle. A specific example of such an embodiment will be described later ( FIG. 5( b) ).

[0096] The control of the operation of the cooling unit 13 based on the difference between the first temperature D1 and the second temperature D2 may be performed throughout the multiple molding cycles MC (from the first molding cycle to the last molding cycle), or may be performed only during some of the multiple molding cycles MC. An example of the latter is a mode in which the control is performed only when the temperature of the mold 101 is not stable (for example, when multiple molding cycles MC are started). Note that although the control is performed throughout the multiple molding cycles MC, strictly speaking, the control is not performed during all molding cycles MC depending on the specific mode of the control. For example, before the first temperature D1 and the second temperature D2 are detected for the first time in the first molding cycle MC, the operation of the cooling unit 13 is controlled based on a predetermined initial setting.

[0097] (Example of how to calculate the manipulated variable based on the first and second temperatures) The control of the operation of the cooling unit 13 based on the difference between the first temperature and the second temperature may be performed in various ways. Below, a relatively simple control mode will be exemplified to explain the control of the operation of the cooling unit 13 based on the difference between the first temperature and the second temperature.

[0098] Assume that in each molding cycle, when the temperature of the mold 101 is detected and a detected temperature Ta is obtained, the cooling unit 13 is controlled with an operation amount u to set the temperature of the mold 101 to a target temperature Tb. In this case, the operation amount u may be calculated, for example, by the following equation (1). u = K(Tb - Ta) (1)

[0099] Note that K is sometimes referred to as the proportional gain. The manipulated variable u is calculated, for example, once per molding cycle. Equation (1) can be regarded as an equation showing proportional control in which the molding cycle period is the feedback period.

[0100] In this embodiment, the control device 5 sets the proportional gain K based on the difference between the first temperature D1 and the second temperature D2. For example, suppose that the first temperature D1 and the second temperature D2 are detected in the same molding cycle, and the manipulated variable from the time the first temperature D1 is detected to the time the second temperature D2 is detected is u. In this case, the proportional gain K to be used in the next molding cycle is calculated by the following equation (2). K=u / (D2-D1) (2)

[0101] Although the same symbols are used for the manipulated variables in equations (1) and (2), they may be different. From another perspective, the time difference between Ta and Tb and the time difference between D2 and D1 may be the same or different.

[0102] The above is an example of a simple mode of controlling the operation of the cooling unit 13 based on the first temperature and the second temperature. Actual control may be performed in various modes other than the above. For example, instead of the above formula, the proportional gain K may be set based on a map correlating D2-D1 (or D1 and D2), the manipulated variable u, and the proportional gain K. The differential gain and / or the integral gain may be calculated based on the history of past molding cycles, etc. Since there is a correlation between the relationship between the manipulated variable and the cooling effect during the period from the first temperature to the second temperature and the relationship between the manipulated variable and the cooling effect during other periods, the manipulated variable during other periods may be adjusted to achieve the target temperature at an appropriate time.

[0103] The above concept can also be applied to an embodiment in which the temperature of multiple regions (or, from another perspective, multiple positions) of the mold 101 is controlled. As described above, the temperatures of the multiple regions may be detected by multiple contact-type temperature sensors 59A and / or by thermographic temperature sensors 59B, or may be obtained by interpolation. Furthermore, the temperature of the multiple regions may be controlled by individually controlling the discharge rates of the multiple nozzles 19 of the spray device 15, by controlling the discharge rate for each region when spraying by sequentially moving the head 21 of the spray device 15 to the multiple regions, and / or by individually controlling the amount of cooling water supplied to the multiple flow paths 107.

[0104] The following equation (3) shows the determinant when the concepts of equations (1) and (2) are expanded to temperatures in multiple regions.

[0105]

number

[0106] Here, ΔT1 to ΔT n indicates the temperature change in the first to nth regions, and corresponds to D2-D1 in equation (2) (or Tb-Ta in equation (1)). n indicates the temperatures of the first to nth regions, and corresponds to D1 in equation (2) (or Ta in equation (1)). m indicates the manipulated variable related to the first to m-th cooling, and corresponds to u in equation (2) (or equation (1)).

[0107] A 11 ~A nn (n × n matrix elements) are coefficients that represent the mutual influence of the first to nth regions on temperature, and more specifically, the temperatures T1 to T n The temperature change ΔT1 to ΔT occurs up to the time of measurement of the second temperature. n The coefficient may be determined based on theory and / or experiments.

[0108] B 11 ~B nm (n × m matrix elements) are the operation variables u1~u m is the temperature change ΔT1~ΔT n This is a coefficient that represents the influence on the 11 ~A nn The measured values ​​T1 to T n and ΔT1 to ΔT n and the operation amount u1~u at the time of measurement m Substituting and, B 11 ~B nmIf the solution of m is obtained, the operation amounts u1 to u for obtaining the target temperature in each of the n regions in the next molding cycle can be obtained.

[0109] The magnitude relationship between the number n of the plurality of regions where the temperature is controlled and the number m of the plurality of operation amounts is arbitrary. That is, it may be any of n = m, n < m, and n > m. As an example of n = m, an aspect using the discharge amount of the spray in n regions can be cited as u1 to u m . As an example of n < m, an aspect using the discharge amount of the spray in n regions and the flow rate of the cooling water in one or more flow paths 107 can be cited as u1 to u m . As an example of n > m, an aspect using the discharge amount of the spray in a number of regions less than the number of divisions of the coated surface 109 for obtaining the temperature distribution can be cited as u1 to u m . As u1 to u m , when the discharge amount of the spray in one or more regions and the flow rate of the cooling water in one or more flow paths 107 are used as the operation amounts, n = m or n < m may be satisfied.

[0110] As understood from the above description, the m operation amounts may be operation amounts corresponding to different regions of the same type of operation amount, or may be different types of operation amounts. Further, the different types of operation amounts may be operation amounts of different cooling elements, such as the difference between the operation amount of the spray device 15 and the operation amount of the internal cooling device 17, or may be different types of operation amounts of the same cooling element, such as the length of time during which the spray is performed and the discharge amount per unit time in the spray.

[0111] (Specific example of the operation of the cooling unit controlled based on the first temperature and the second temperature) As also mentioned above, the operation of the cooling unit 13 controlled based on the first temperature and the second temperature may be various. From another perspective, the operation of the cooling unit 13 that changes according to the change in the difference between the first temperature and the second temperature or the physical quantity related to the operation may be various.

[0112] For example, with regard to the operation of the spray device 15, the length of time for which spraying is performed, the amount of release agent dispensed per unit time during spraying, and / or the temperature of the release agent may be adjusted. Adjustment of the length of time and / or the amount of release agent dispensed per unit time may be performed as a type of adjustment of the total amount of release agent dispensed over the entire spray period. Furthermore, adjustment of the physical quantity may be performed only for some of the nozzles 19 or for all of the nozzles 19. Furthermore, the amount of adjustment of the physical quantity may be different for each nozzle 19 or for two or more nozzles 19, or may be the same for all of the nozzles 19.

[0113] Furthermore, for example, with regard to the operation of the internal cooling device 17, the length of time for which cooling water is supplied to the mold 101, the flow rate of the cooling water per unit time, and / or the temperature of the cooling water may be adjusted. Adjustment of the length of time and the flow rate per unit time may be performed as a type of adjustment of the total amount of cooling water supplied to the mold 101 over the entire molding cycle period. Furthermore, adjustment of the physical quantity may be performed only for some of the multiple flow paths 107, or for all of the flow paths 107. Furthermore, the adjustment amount of the physical quantity may be different for each flow path 107 or for two or more flow paths 107, or may be common to all of the flow paths 107.

[0114] FIG. 5(a) is a timing chart showing an example of a mode for controlling the length of time for which cooling water is supplied to the mold 101 based on the first temperature and the second temperature.

[0115] In this figure, the horizontal axis represents elapsed time t. The vertical axis represents the flow rate Q of cooling water per unit time supplied to the mold 101 (or one or more flow paths 107; the same applies below). On the horizontal axis, time t1 represents the start of a molding cycle MC (or the end of the previous molding cycle MC). For ease of illustration, time t1 is taken to be the start of the period during which spraying is performed (spray period SP) and the time when the first temperature D1 is detected. Time t2 is taken to be the end of the spray period SP. For ease of illustration, time t2 is taken to be the time when the second temperature D2 is detected. In the explanation of FIG. 5(a), the spray period SP may be interpreted as the detection period DP (symbol: FIG. 6(a)) from the detection of the first temperature D1 to the detection of the second temperature D2.

[0116] In this example, cooling water is supplied intermittently within each molding cycle. The flow rate Q when cooling water is supplied is set to a constant flow rate Qc. That is, the internal cooling device 17 allows or prohibits the supply of cooling water, but does not control the flow rate Q. The internal cooling device 17 (or the control device 5 from another perspective) controls the length of time for which cooling water is supplied based on the difference between the first temperature D1 and the second temperature D2.

[0117] More specifically, in the illustrated example, the internal cooling device 17 starts supplying cooling water during the spray period SP of each molding cycle MC, and stops supplying cooling water at an appropriate time after the spray period SP. Examples of times to stop supplying cooling water include when mold opening begins, when mold opening is completed, and when extrusion of the molded product is completed. Unlike the illustrated example, the supply of cooling water may be stopped after the next molding cycle is started (but before the supply of cooling water for the next molding cycle begins).

[0118] Then, the internal cooling device 17 changes the start time of the supply of cooling water in the molding cycle following the molding cycle MC in which the first and second temperatures were detected, depending on the difference between the first and second temperatures. This changes the length of time for which cooling water is supplied. Figure 5(a) illustrates a situation in which the length of time is increased from TM1 to TM2. Note that the illustrated example may be interpreted as changing the length of time for which cooling water is supplied from TM5 to TM6 within the spray period SP.

[0119] FIG. 5(b) is a timing chart showing an example of a mode in which the flow rate per unit time of the cooling water supplied to the mold 101 is controlled based on the first temperature and the second temperature.

[0120] In this figure, the horizontal axis (elapsed time t), vertical axis (flow rate Q per unit time), time t1, and time t2 are the same as those in Figure 5(a). Here, too, the spray period SP may be interpreted as the detection period DP (symbol shown in Figure 6(a)) from the detection of the first temperature D1 to the detection of the second temperature D2.

[0121] In this example, cooling water is continuously supplied throughout the entire molding cycle MC. The flow rate Q of the cooling water is set to any value or one of multiple preset values. The internal cooling device 17 (or the control device 5 from another perspective) controls the flow rate Q based on the difference between the first temperature D1 and the second temperature D2.

[0122] More specifically, in the illustrated example, the internal cooling device 17 changes the flow rate Q at a predetermined time t3 and maintains the flow rate Q until time t3 of the next molding cycle MC. Time t3 may be any time within the molding cycle MC. For example, time t3 may be located within the period from the end of the spray period SP to the start of injection (the time when the temperature of the mold 101 starts to rise), or may be during the start of injection, or after the completion of injection. Furthermore, unlike the illustrated example, time t3 may be the period from the start of the molding cycle MC to the start of spraying in an embodiment in which spraying starts after the start of the molding cycle MC. Furthermore, time t3 may be within the spray period.

[0123] The internal cooling device 17 then changes the flow rate Q in accordance with the difference between the first and second temperatures at the first time point t3 after the time point at which the first and second temperatures are detected (in the illustrated example, time point t3 within the same molding cycle MC as the molding cycle at which the first and second temperatures are detected). FIG. 5(b) illustrates a situation in which the flow rate Q increases from Q1 to Q2, and then from Q2 to Q3. Note that the illustrated example may be interpreted as the flow rate Q being changed from the flow rate Q within the spray period SP in the molding cycle at which the first and second temperatures are detected to the flow rate Q within the spray period SP in the next molding cycle.

[0124] FIG. 6(a) is a timing chart showing an example of an aspect in which the length of time for spraying is controlled based on the first temperature and the second temperature.

[0125] In this figure, the horizontal axis represents elapsed time t. The vertical axis represents the amount q of release agent discharged per unit time from one nozzle 19, two or more nozzles 19, or all nozzles 19 (hereinafter simply referred to as nozzles 19; the same applies to the explanation of FIG. 6(b)). On the horizontal axis, time t1 represents the start of the molding cycle MC, as in FIG. 5(a), and is also the detection time of the first temperature D1 (the start of the detection period DP). However, here, unlike FIG. 5(a), time t1 is not the start of the spray period SP. Also, time t2 is the detection time of the second temperature D2 (the end of the detection period DP), as in FIG. 5(a). However, here, unlike FIG. 5(a), time t2 is not the completion time of the spray period SP.

[0126] In this example, the discharge amount q of the release agent when spraying is set to a constant discharge amount qc. That is, the spray device 15 controls the time length for spraying (TM11 and TM12), but does not control the discharge amount q. The spray device 15 (or the control device 5 from another perspective) controls the time length for spraying based on the difference between the first temperature D1 and the second temperature D2.

[0127] More specifically, in the illustrated example, the spray device 15 starts and completes spraying within the detection period DP of each molding cycle MC. Then, the spray device 15 changes the duration (TM11 and TM12) of spraying in the molding cycle following the molding cycle in which the first and second temperatures were detected, depending on the difference between the first and second temperatures. This change may be made by changing the start time of spraying, the completion time of spraying, or both (illustrated example). Figure 6(a) illustrates a situation in which the duration of spraying is increased from TM11 to TM12.

[0128] 6(b) is a timing chart showing an example of controlling the amount of release agent discharged per unit time based on the first and second temperatures. In this diagram, the horizontal axis (elapsed time t), the vertical axis (discharge amount per unit time q), time t1, and time t2 are the same as those in FIG. 6(a).

[0129] In this example, the time length for spraying is a fixed time length TMc. Meanwhile, the release agent discharge amount q is set to an arbitrary value or one of several preset values. Then, the spray device 15 (or, from another perspective, the control device 5) changes the discharge amount q in the molding cycle following the molding cycle in which the first temperature D1 and the second temperature D2 were detected, based on the difference between the first temperature D1 and the second temperature D2. The example in FIG. 6(b) illustrates a situation in which the discharge amount increases from q1 to q2. Note that, in the illustrated example, the fixed time length TMc is set shorter than the detection period DP and falls within the detection period DP. However, as can be understood from the above explanation, the time length TMc is not limited to such a mode.

[0130] As described above, equation (1) may be regarded as an equation indicating control in which feedback is performed in a period of one molding cycle. Naturally, to achieve such control, normal feedback control may be performed in a period shorter than the molding cycle. For example, in the example of FIG. 5(b), the flow rates Q1, Q2, or Q3, or the value obtained by multiplying these flow rates by the molding cycle (total amount of cooling water in one molding cycle), may be regarded as an example of the manipulated variable u in equation (1). In this case, the manipulated variable (different from the manipulated variable u) of the valve 45 may be calculated from the deviation between the detected value of the flow rate Q and the flow rate Q1, Q2, or Q3 in a period shorter than the molding cycle, and feedback control may be performed.

[0131] (Summary of the embodiment) As described above, the die-casting machine 1 according to this embodiment repeats molding cycles MC and includes a machine main body 3, a cooling unit 13, and a control device 5. The machine main body 3 sequentially performs mold closing, injection, and mold opening during each molding cycle. The cooling unit 13 cools the mold (die 101) during each molding cycle. The control device 5 controls the cooling unit 13 based on a signal from a sensor (temperature sensor 59) that detects the temperature of the die 101. The cooling unit 13 includes a spray device 15 that sprays the die 101 before closing during each molding cycle. The control device 5 controls the operation of the cooling unit 13 based on the temperature difference between a first temperature D1 detected by the temperature sensor 59 before spraying and a second temperature D2 detected by the temperature sensor 59 after spraying during the molding cycle in which the first temperature D1 was detected.

[0132] Therefore, for example, as described above, it is possible to quantitatively grasp the cooling effect of the cooling unit 13 and specify the amount of operation of the cooling unit 13 required to obtain the target temperature, etc. As a result, the accuracy of temperature control of the mold 101 is improved.

[0133] The control device 5 may control the operation of the cooling section 13 when spraying is performed in the next molding cycle based on the difference between the first temperature and the second temperature in each molding cycle.

[0134] In this case, for example, the temperature is detected for each molding cycle, and the detection result is immediately reflected in the control of the cooling unit 13, thereby quickly improving the accuracy of control. Also, for example, the cooling unit 13 is controlled during the spray period of the next molding cycle based on the temperature during the spray period, so when the molding cycle is repeated, there is a high correlation between the control content and the temperature detection result. As a result, for example, when the molding cycle is repeated, the control tends to be stable, and ultimately the accuracy of control is improved.

[0135] In addition, when it says "based on the difference between the first temperature and the second temperature in each molding cycle," the first temperature and the second temperature detected in the previous molding cycle may be used along with the first temperature and the second temperature detected in the current molding cycle, as in the case of using a moving average value of the first temperature and the second temperature. In addition, when it says "controlling the operation of the cooling unit when spraying is performed in the next molding cycle," as in the example of Figure 5(b), the change itself according to the difference between the first temperature and the second temperature may occur in the current molding cycle, and the state after the change may be maintained in the next molding cycle.

[0136] The cooling section 13 may include an internal cooling device 17 that supplies a coolant (e.g., water) into a flow path 107 provided in the mold 101. The control device 5 may adjust a physical quantity related to the cooling water thereafter (e.g., in the subsequent molding cycle) based on the difference between the first temperature and the second temperature within the same molding cycle.

[0137] The operation of the internal cooling device 17 is easier to change than that of the spray device 15. Specifically, the operation of the spray device 15 is controlled taking into consideration not only the cooling effect but also the effects of seizure and / or mold release resistance. On the other hand, the internal cooling device 17 does not basically require any other effects from the cooling water. Therefore, the operation of the internal cooling device 17 can be flexibly changed. Temperature detection is performed based on the spray period, when the temperature drop of the mold 101 is large, while the internal cooling device 17 adjusts the cooling effect based on the detected temperature, thereby enabling optimal temperature control of the entire die casting machine 1.

[0138] The physical quantity related to the cooling water may include the length of time during which the cooling water is supplied into the flow path 107 in each molding cycle (FIG. 5(a)).

[0139] In this case, for example, the need to adjust the flow rate of the cooling water is reduced. As a result, for example, the need to provide a flow rate control valve (or the need to increase the accuracy of the flow rate control valve) is reduced, and cost reduction of the internal cooling device 17 is facilitated.

[0140] The physical quantity related to the cooling water may include the flow rate Q of the cooling water per unit time flowing into the flow path 107 during a predetermined period in each molding cycle (FIG. 5(b)). In the example of FIG. 5(b), the "predetermined period" corresponds to the length of the molding cycle from time t3 to the next time t3. The spray period SP or the detection period DP may be considered to correspond to the predetermined period.

[0141] In this case, for example, the gradient of the temperature change of the mold 101 can be changed by changing the flow rate Q. In other words, the timing at which the gradient of the temperature change of the mold 101 changes can be maintained. Therefore, for example, the likelihood of an unintended temperature change occurring due to a change in the interrelationship between the timing of cooling by the internal cooling device 17, the timing of temperature change due to the operation of the machine body 3, and the timing of cooling by spraying is reduced.

[0142] The control device 5 may adjust the physical amount related to the spray in the subsequent molding cycle based on the difference between the first temperature and the second temperature in the same molding cycle.

[0143] In this case, for example, the operation of the cooling means, which is highly correlated with the difference between the first temperature and the second temperature, is controlled. As a result, for example, when the manipulated variable related to cooling based on the first temperature and the second temperature is repeatedly corrected as the molding cycle is repeated, the temperature of the mold 101 tends to stabilize (temperature changes within a molding cycle tend to be similar across multiple molding cycles).

[0144] The physical quantity related to the spraying may include the time during which the spraying is performed within each molding cycle (FIG. 6(a)).

[0145] In this case, similar to the aspect of adjusting the time for supplying cooling water to the flow path 107, the need to provide a flow control valve (or the need to increase the accuracy of the flow control valve) is reduced, making it easier to reduce the cost of the spray device 15.

[0146] The physical quantity related to the spray may include the amount of liquid (discharge amount q) ejected by the spray per unit time in each molding cycle.

[0147] In this case, for example, the timing at which the gradient of the temperature change in the mold 101 changes can be maintained, similar to the aspect of changing the flow rate Q of the cooling water. As a result, for example, the likelihood of an unintended temperature change occurring due to a change in the correlation with the timing of the operation of other components that affect the temperature change is reduced.

[0148] The die 101 is replaced as needed by the user of the die-casting machine 1. The temperature sensor 59 may be attached to the die 101. Therefore, the die-casting machine 1 may be regarded as a machine that does not include the die 101 and the temperature sensor 59, or as a machine that includes the die 101 and the temperature sensor 59.

[0149] Furthermore, a spray device that can be considered as a device including a spray control unit 55 can be extracted from the die casting machine 1 according to this embodiment. The spray device may have a spray device main body (the spray device 15 when the spray device 15 and the control device 5 are considered as separate components) and a spray control unit 55. When a molding cycle including mold closing, injection, and mold opening is repeated, the spray device 15 sprays toward the mold (mold 101) before mold closing during each molding cycle. The spray control unit 55 may control the spray device 15 based on a signal from a sensor (temperature sensor 59) that detects the temperature of the mold 101. Furthermore, the spray control unit 55 may control the operation of the spray device 15 during a subsequent molding cycle based on the temperature difference between a first temperature D1 detected by the temperature sensor 59 before spraying and a second temperature D2 detected by the temperature sensor 59 after spraying during the molding cycle in which the first temperature D1 was detected.

[0150] The spray device including such a spray control unit 55 may be distributed (or may be capable of being distributed) separately from the machine main body 3 and the main body control unit 53, or may not be distributed (or may not be capable of being distributed) separately. In either embodiment, the spray device may or may not include a temperature sensor 59.

[0151] The technology according to the present disclosure is not limited to the above-described embodiments and may be implemented in various forms.

[0152] For example, the molding machine is not limited to a die-casting machine. For example, the molding machine may be another metal molding machine, an injection molding machine for molding resin, or a molding machine for molding a material in which wood powder is mixed with a thermoplastic resin or the like. Furthermore, the molding machine is not limited to a horizontal clamping / horizontal injection molding machine, and may be, for example, a vertical clamping / vertical injection molding machine, a vertical clamping / horizontal injection molding machine, or a horizontal clamping / vertical injection molding machine.

[0153] In the example of Fig. 5(b), the flow rate Q is changed over the entire period corresponding to the molding cycle (the period from time t3 to the next time t3). However, the flow rate Q may be changed only for a part of the period (for example, the spray period SP or the detection period DP).

[0154] In the embodiment, the operation of the cooling unit in the molding cycle following the molding cycle in which the first and second temperatures were detected is adjusted based on the difference between these temperatures. However, the operation of the cooling unit may be adjusted based on the first and second temperatures only within the molding cycle in which these temperatures were detected.

[0155] For example, in the example of Figure 5(a), the time for which cooling water is supplied within the spray period SP (within the detection period DP) may be the same for multiple molding cycles.Then, based on the difference between the first temperature and the second temperature, the time for which cooling water is supplied may be adjusted only within the molding cycle in which these temperatures are detected.Similarly, in the example of Figure 5(b), the flow rate Q within the spray period SP (within the detection period DP) may be the same for multiple molding cycles.Then, based on the difference between the first temperature and the second temperature, the flow rate Q may be adjusted only within the molding cycle in which these temperatures are detected.

[0156] As can be seen from the above, even if the difference between the first and second temperatures changes with the repetition of the molding cycle, the operation of the cooling unit within the detection period DP (spray period SP) may be the same across multiple molding cycles. In this aspect, for example, when the cooling effect of the cooling unit relative to the operating amount of the cooling unit changes due to some abnormality or a change in the environmental temperature, adjustments can be made in response to the change. Furthermore, in the embodiment, in which the operation of the cooling unit within the detection period DP of the subsequent molding cycle is adjusted in response to the difference between the first and second temperatures, adjustments can be made taking into account, for example, the effect of a change in the operating amount of the cooling unit on a change in the cooling effect of the cooling unit. [Explanation of symbols]

[0157] 1...Die-casting machine (molding machine), 3...Machine body, 5...Control device, 13...Cooling section, 15...Spray device, 59...Temperature sensor (sensor), 101...Mold (die).

Claims

1. A die casting machine that repeats molding cycles, A machine body that performs mold closing, injection, and mold opening in order in each molding cycle; a cooling section for cooling the mold within each molding cycle; a control device that controls the cooling unit based on a signal from a sensor that detects the temperature of the mold; It has The cooling unit includes a spray device that sprays toward the mold before the mold is closed in each molding cycle, The control device controlling the cooling unit with an operation amount based on a proportional gain and a difference between a predetermined target temperature and a temperature detected by the sensor for each molding cycle; The proportional gain is reset based on a temperature difference between a first temperature detected by the sensor at a first time point before the spraying and a second temperature detected at a second time point after the spraying in the molding cycle in which the first temperature was detected, and the manipulated variable of the control of the cooling unit executed from the first time point to the second time point. Molding machine.

2. The control device controls the operation of the cooling unit when the spraying is performed in the next molding cycle of each molding cycle based on the temperature difference within each molding cycle. The molding machine according to claim 1.

3. the cooling unit includes an internal cooling device that supplies a refrigerant into a flow path provided in the mold, The control device adjusts a physical quantity related to the refrigerant based on the temperature difference. The molding machine according to claim 1 or 2.

4. The physical quantity related to the refrigerant includes the length of time during which the refrigerant is supplied into the flow path in each molding cycle. The molding machine according to claim 3.

5. The physical quantity related to the refrigerant includes a flow rate per unit time of the refrigerant flowing into the flow path during a predetermined period in each molding cycle. The molding machine according to claim 3 or 4.

6. The control device adjusts a physical quantity related to the spray based on the temperature difference. The molding machine according to any one of claims 1 to 5.

7. The physical quantity related to the spray includes the time during which the spray is performed in each molding cycle. The molding machine according to claim 6.

8. The physical quantity related to the spray includes the amount of liquid ejected by the spray per unit time in each molding cycle. The molding machine according to claim 6 or 7.

9. The mold; the sensor; The molding machine according to any one of claims 1 to 8, further comprising:

10. A spray device body that sprays toward the mold before it is closed during each molding cycle when a molding cycle including mold closing, injection, and mold opening is repeated; a spray control unit that controls the spray device body based on a signal from a sensor that detects the temperature of the mold; It has The spray control unit The spray device main body is controlled with an operation amount based on a difference between a predetermined target temperature and the temperature detected by the sensor and a proportional gain for each molding cycle; The proportional gain is reset based on a temperature difference between a first temperature detected by the sensor at a first time point before the spraying and a second temperature detected at a second time point after the spraying in the molding cycle in which the first temperature was detected, and the manipulated variable of the control of the spray device main body executed from the first time point to the second time point. Spray device.

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