Molding machine, and method for controlling molding machine

Abstract

Provided is a molding machine comprising a mold, a mold opening means, driven by hydraulic pressure, for opening the mold, and a control means for controlling the position of the mold through the mold opening means, wherein the control means corrects the stroke of the mold for a mold opening process of the next molding, on the basis of the difference between an actual value and a target value of the position of the mold at the completion of the mold opening.

Description

Molding machine and molding machine control method

[0001] The present invention relates to shortening the cycle time of molding machines such as die-casting machines.

[0002] The prior art of Patent Document 1 describes a die casting machine that performs feedback control of the valve opening based on the speed of the plunger during injection.

[0003] JP 2019-150861 A

[0004] However, the above-mentioned prior art merely involves feedback control during injection, and there is no particular mention of the mold opening process.

[0005] The present invention has been made in consideration of the above circumstances, and its purpose is to shorten the distance between the molds when they are opened by performing feedback control during the mold opening process, thereby shortening the cycle time including mold opening and mold clamping.

[0006] In order to solve the above problems, the present invention provides a molding machine that includes a mold, a mold opening means that is hydraulically driven and opens the mold, and a control means that controls the position of the mold via the mold opening means, wherein the control means corrects the stroke of the mold based on the difference between the target value and actual value of the position of the mold at the time the mold opening is completed.

[0007] This reduces the distance between the molds when they are opened, thereby shortening the casting cycle time.

[0008] Fig. 1 is a diagram showing an example of a die-casting machine to which the present invention is applied, Fig. 2 is a diagram showing a mold opening process, and Fig. 3 is a flowchart of the present invention.

[0009] The present invention will now be described in detail with reference to the accompanying drawings.

[0010] [Overall Configuration] Figure 1 shows a die-casting machine according to the molding machine of the present invention. The die-casting machine 1 shown in Figure 1 is a device that produces a product (casting) by filling a mold with molten metal (hereinafter referred to as "molten metal") and molding it. As shown in Figure 1, the die-casting machine 1 includes an injection device 10, a mold 20, a mold opening means 30, and a control means 100.

[0011] The injection device 10 is a device that injects and fills a molten metal into a cavity formed in a mold 20. The injection device 10 has, for example, an injection sleeve 11, a plunger 12, and an injection cylinder 13. The injection sleeve 11 is a member that guides the molten metal into the cavity of the mold 20, and is formed, for example, in a cylindrical shape that extends horizontally in one direction. The injection sleeve 11 is provided with a pouring port 11a, and the molten metal is supplied to the space within the injection sleeve 11 through the pouring port 11a.

[0012] The injection cylinder 13 is connected to the plunger 12 arranged in the injection sleeve 11 and is a member that drives the plunger 12. The injection cylinder 13 may be a hydraulically driven cylinder. When the injection cylinder 13 advances the plunger 12 toward the mold 20, the molten metal in the injection sleeve 11 is injected and filled into the cavity of the mold 20. The space within the injection sleeve 11 and the cavity formed in the mold 20 are connected to each other.

[0013] The mold 20 is a component that forms a cavity corresponding to the product (cast product). The mold 20 has a fixed mold 21 and a movable mold 22, and mold opening is performed by moving the movable mold 22 (mold) using a mold opening means 30. The fixed mold 21 is fixed to a fixed platen 27 provided in the die casting machine 1. The movable mold 22 is fixed to a movable platen 28 provided in the die casting machine 1. The movable platen 28 is arranged to move in one horizontal direction. The movable mold 22 moves in conjunction with the movement of the movable platen 28.

[0014] 1 , one horizontal direction in which the movable platen 28 (movable mold 22) moves is indicated by an arrow with an "X" attached. "Mold opening" is performed when the movable mold 22 moves in a direction away from the fixed mold 21 from a state in which the movable mold 22 has come into contact with the fixed mold 21 to form a cavity. "Mold clamping" is performed when the movable mold 22 moves in a direction approaching the fixed mold 21 from a state in which the fixed mold 21 and the movable mold 22 are not in contact with each other to a position where a cavity is formed.

[0015] The mold opening means 30 is a hydraulic actuator driven by a hydraulic source (not shown). The mold opening means 30 is a device that drives (moves) the movable platen 28 along the direction X. The mold opening means 30 has, for example, a hydraulic cylinder 31 and a toggle mechanism 38. The hydraulic cylinder 31 is connected to the movable platen 28 via the toggle mechanism 38. The toggle mechanism 38 functions as a link arm. The hydraulic cylinder 31 reciprocates the movable platen 28 in the direction X via the toggle mechanism 38.

[0016] The hydraulic cylinder 31 includes a cylinder container 32, a cylinder rod 33, and a cylinder head 34. The cylinder container 32 forms a space for movement of some of the components included in the hydraulic cylinder 31. The cylinder rod 33 is a rod-shaped member formed to extend along the direction X. One end of the cylinder rod 33 is connected to the cylinder head 34, and the other end of the cylinder rod 33 is connected to a toggle mechanism 38.

[0017] The interior of the cylinder container 32 is divided into two spaces in the direction X by the cylinder head 34. Of the two spaces, the space where the cylinder rod 33 is located is called the "rod-side hydraulic chamber," and the space where the cylinder rod 33 is not located is called the "head-side hydraulic chamber." For example, mold clamping is performed by supplying hydraulic oil to the head-side hydraulic chamber, and mold opening is performed by supplying hydraulic oil to the rod-side hydraulic chamber.

[0018] The mold opening means 30 may have a hydraulic oil supply unit 36. The hydraulic oil supply unit 36 ​​is a portion inside the cylinder container 32 configured to supply hydraulic oil to the rod-side hydraulic chamber. The hydraulic oil supply unit 36 ​​may include a pipe and a valve that opens and closes the inside of the pipe. In the hydraulic oil supply unit 36, a state in which hydraulic oil is supplied and a state in which hydraulic oil is not supplied may be switched by opening and closing the valve. In the hydraulic oil supply unit 36, the flow rate (flow rate per unit time) of hydraulic oil supplied to the rod-side hydraulic chamber may be adjusted by the opening degree of the valve.

[0019] The mold opening means 30 may have a position sensor 37. The position sensor 37 is a sensor that acquires information indicating the position of the movable mold 22. The position sensor 37 acquires information indicating the position of the movable mold 22 in the direction (direction X) in which the movable mold 22 moves as the mold is opened. The position sensor 37 may acquire the information indicating the position of the movable mold 22, for example, by detecting the position of the cylinder rod 33 or the cylinder head 34. The position sensor 37 outputs the information indicating the position of the movable mold 22 to the control means 100.

[0020] The control means 100 controls the position and stroke (amount of movement) of the movable mold 22. The control means 100 is one or more computers configured to control at least the mold opening means 30. When the control means 100 is configured with two or more computers, the two or more computers may be connected to each other so that they can communicate with each other. The control means 100 may control the mold opening means 30 so that the movable mold 22 approaches the fixed mold 21 when mold clamping is performed. The control means 100 may control the mold opening means 30 so that pressure from the movable mold 22 continues to be applied to the fixed mold 21 even after the movable mold 22 comes into contact with the fixed mold 21 when mold clamping is performed.

[0021] The control means 100 may control the mold opening means 30 so that the movable mold 22 moves away from the fixed mold 21 when mold opening is performed. The control means 100 may control the mold opening means 30 so that the movable mold 22 stops before reaching the limit position to which the movable mold 22 can be moved when mold opening is performed. The stroke of the movable mold 22 when mold opening may be the amount of movement of the movable mold 22 when the position of the movable mold 22 in a state in which mold clamping continues is set as a reference position (0). The stroke of the movable mold 22 is calculated based on the stroke of the mold opening means 30 (the movable part of the mold opening means 30). In FIG. 1 , the position of the movable mold 22 when mold clamping is performed is represented by "0", and the stroke of the movable mold 22 associated with mold opening is represented by "x". The position of the movable mold 22 in direction X is represented by "p", and the limit position to which the movable mold 22 can be moved is represented by "Pm".

[0022] The control means 100 includes, for example, a circuit 102 as a hardware configuration. The circuit 102 may have a processor, memory, storage, and input / output ports. The storage of the circuit 102 may be configured with one or more non-volatile memory devices such as flash memory or a hard disk. The memory of the circuit 102 is configured with one or more volatile memory devices such as random access memory. The memory temporarily stores programs loaded from the storage. The processor of the circuit 102 is configured with one or more arithmetic devices such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit). The input / output ports of the circuit 102 input and output information to and from the mold opening means 30, etc., in response to a request from the processor.

[0023] [Casting Process] During the period when the die-casting machine 1 is operating (hereinafter referred to as the "operating period"), the casting process is repeatedly performed to obtain one molded product (cast product). In the casting process, for example, a mold clamping process, a filling process, a mold opening process, a removal process, and a spraying process are performed in this order. The mold clamping process is a process of clamping the mold 20. In the mold clamping process, the control means 100 controls the mold opening means 30 to perform mold clamping. The filling process is a process of filling the cavity formed in the mold 20 with molten metal while the mold is continuously clamped.

[0024] The mold opening process is a process of opening the mold 20 after the filling process is completed. In the mold opening process, the mold opening means 30 is controlled by the control means 100 to open the mold. The removal process is a process of removing the casting remaining in the mold 20 after the mold opening has been completed. For example, a robot provided in the die-casting machine 1 removes the product (casting). The spraying process is a process of spraying (applying) a release agent to the mold 20 after the mold opening has been completed. For example, the release agent is sprayed by a robot provided in the die-casting machine 1 and a spray device attached to the robot. The mold opening process will be described in detail below.

[0025] [Mold Opening Process] Figure 2 is a diagram showing the position of the mold (movable mold 22) during the mold opening process and each process during mold opening. The horizontal axis represents the position of the movable mold 22. The mold opening process may consist of, for example, four processes: (A) a mold release process, (B) a high-speed mold opening process, (C) a deceleration process, and (D) a sliding process. The movable mold 22 moves from the mold opening start position to the mold opening end position through these four processes.

[0026] (A: Demolding Process) At the mold opening start position, the movable mold 22 moves in the demolding direction, starting the demolding process. Moving in the demolding direction means that the movable mold 22 moves in a direction away from the fixed mold 21. The movement distance of the movable mold 22 during the demolding process is a preset value and is not changed by control. In one example, the control means 100 executes demolding control in the demolding process, moving the movable mold 22 by a predetermined first stroke (the distance from the mold opening start position in FIG. 2 to the start position of the high-speed mold opening process B). When the mold opening process is repeated, the first stroke is constant (it is executed at a constant stroke to suppress product deformation, etc.). During the demolding control, the hydraulic oil supply unit 36 ​​may supply hydraulic oil to the rod-side hydraulic chamber in the cylinder container 32 at a predetermined flow rate. For example, the demolding process ends when the movable mold 22 moves by the first stroke.

[0027] In the above, the demolding process is continued until the movable mold 22 has moved a certain distance, but the demolding process may be continued until a predetermined time has elapsed from the start of demolding, regardless of the distance. For example, the time required for the demolding process may be set in advance, and the demolding process may end when this time has elapsed (in this case, the speed of the movable mold 22 is also set in advance). In either case, the demolding process continues until the predetermined distance or time has elapsed, and is not changed by control.

[0028] (B: High-Speed ​​Mold Opening Process) After the mold release process is completed, the process transitions to the high-speed mold opening process. In this process, the mold opening means 30 is hydraulically driven to quickly move the movable mold 22 in the mold opening direction. Because the movable mold 22 moves quickly in this process, the cycle time can be shortened. The movement distance (stroke) in this high-speed mold opening process is controlled by the control means 100. In the present invention, the stroke in this high-speed mold opening process is the object of control. By appropriately correcting and changing this stroke, the position of the movable mold 22 at the end of mold opening can be brought closer to a target value. By bringing the position of the movable mold 22 at the end of mold opening closer to the target value, the mold-to-mold distance required for product removal and mold release agent application can be secured while preventing the movable mold 22 (movable platen) from moving excessively in the mold opening direction. Details will be described later (see FIG. 3 ).

[0029] In one example, the control means 100 executes high-speed mold opening control in the high-speed mold opening process, moving the movable mold 22 by a set stroke (B in FIG. 2 : the distance from the start position of the high-speed mold opening process to the start position of the deceleration process, i.e., x(n)) at a higher speed than in the mold release control. The set stroke is the stroke to be controlled. The set stroke does not change during the execution of one mold opening process. During the execution of the high-speed mold opening control, the hydraulic oil supply unit 36 ​​may supply hydraulic oil to the rod-side hydraulic chamber in the cylinder container 32 at a predetermined flow rate. The flow rate in the high-speed mold opening control may be set to a value greater than that in the mold release control. When the movable mold 22 reaches the deceleration start position, the high-speed mold opening process ends. For example, the distance from the mold opening start position (reference position: 0) to the deceleration start position corresponds to the sum of the first stroke and the set stroke.

[0030] (C: Deceleration process) After the high-speed mold opening process is completed, the process moves to the deceleration process. In this deceleration process, the mold opening means 30 is driven at a speed slower than in the high-speed mold opening process. Therefore, the mold 22 moves in the mold opening direction while decelerating. The movement distance of the movable mold 22 in this deceleration process is also a preset value. When the movement distance from the start of the deceleration process reaches a preset value, the deceleration process ends. When the movement distance from the start of the deceleration process reaches a preset value, the movable mold 22 reaches the deceleration end position. The deceleration process ends by stopping the supply of hydraulic oil from a hydraulic device not shown. However, due to inertia, the movable mold 22 continues to move in the mold opening direction even after the deceleration process is completed (sliding process, described below).

[0031] In one example, the control means 100 executes deceleration control in the deceleration process, moving the movable mold 22 by a predetermined second stroke while reducing the speed compared to the high-speed mold opening control. When the mold opening process is repeated, the second stroke is constant (a constant stroke is set to prevent sudden deceleration because sudden deceleration may cause shock due to a sudden hydraulic fluctuation). During the execution of the deceleration control, the hydraulic oil supply unit 36 ​​may supply hydraulic oil to the rod-side hydraulic chamber in the cylinder container 32 at a predetermined flow rate. The flow rate in the deceleration control may be set to a value smaller than that in the high-speed mold opening control. For example, the deceleration process ends when the movable mold 22 moves by the second stroke and the supply of hydraulic oil from the hydraulic oil supply unit 36 ​​is stopped. The second stroke corresponds to the distance (movement amount) from the deceleration start position to the deceleration end position.

[0032] (D: Sliding Process) After the deceleration process is completed, the process moves to the sliding process. In this sliding process, the mold opening means 30 is not driven, but the movable mold 22 moves due to inertia. The sliding process also ends when the movable mold 22 stops. In FIG. 2, the "actual stop position" (mold opening end position) indicates the position of the movable mold 22 at the time when it stops. In the sliding process, the movable mold 22 moves due to inertia, so the actual stop position may deviate from the target stop position. The target stop position may be set to a position moved a certain distance from the deceleration end position. The amount of movement (stroke) from the mold opening start position to the target stop position is the target stroke. Because the sliding process is included, the sum of the first stroke, the set stroke, and the second stroke (the distance from the mold opening start position to the deceleration end position) is smaller than the target stroke.

[0033] If the position of the movable mold 22 does not reach the target stop position after the sliding process is completed, there is a risk of interference with a robot or the like that removes the cast product. Therefore, a threshold is set at a predetermined position from the target stop position toward the fixed mold 21, and if the position of the movable mold 22 after the sliding process is completed is closer to the fixed mold 21 than this threshold, the mold opening operation is performed again to move the movable mold 22 in the mold opening direction, and the movement of the movable mold 22 is repeated until the distance from the target stop position becomes equal to or less than the threshold.

[0034] [Flowchart] Figure 3 is a flowchart of stroke correction in the high-speed mold opening process of the present invention. Because the movable mold 22 is hydraulically driven, the target stop position (target value) often deviates from the actual stop position (actual value). Therefore, the difference Δx between the target and actual stop position values ​​in the nth (n is an integer greater than or equal to 1) casting is calculated, and feedback control is performed to correct the stroke of the high-speed mold opening process in the next casting (n+1th) based on this difference Δx, thereby bringing the stop position of the movable mold 22 closer to the target value. The difference Δx is calculated, for example, by subtracting the target stop position value from the actual stop position value. The series of steps S1 to S5 in the flowchart shown in Figure 3 are performed each time a casting (a mold opening operation) is performed. Each step is described below.

[0035] In step S1, the mold opening process (mold release process) for the nth casting is initiated. In step S1, the stroke of the high-speed mold opening process is further set to x(n). In step S1, for example, the control means 100 sets the stroke of the high-speed mold opening process to x(n). Note that the stroke x(1) of the high-speed mold opening process for the first casting (n=1) is set to an initial value. In the second and subsequent castings, the stroke x(n+1) calculated for the previous casting is used as x(n). In step S1, the control means 100 may control the mold opening means 30 so that the mold release process and the high-speed mold opening process are performed in sequence. The stroke x(n) corresponds to the set stroke in the high-speed mold opening control described above.

[0036] In step S2, the stroke x(n) of the mold opening process ends, the movable mold 22 reaches the deceleration position, and the deceleration process begins. That is, after the high-speed mold opening process included in the mold opening process begins, the movable mold 22 moves by the stroke x(n), and reaches the deceleration start position. In step S2, for example, the control means 100 controls the mold opening means 30 to execute the deceleration process.

[0037] In step S3, the movable mold 22 stops and mold opening is completed. In step S3, for example, the control means 100 controls the mold opening means 30 to end the deceleration process after the movable mold 22 reaches the deceleration end position. Then, the movable mold 22 goes through the sliding process and stops.

[0038] In step S4, the stop position (actual value) of the movable mold 22 is detected, and the difference Δx(n) between this and the target value for the stop position for the current casting (nth casting) is calculated. In step S4, for example, the control means 100 detects the actual stop position of the movable mold 22 based on information from the position sensor 37. The control means 100 may calculate the target value for the stop position for the current casting by adding a constant value to the stroke x(n) in the high-speed mold opening step for the current casting (nth casting).

[0039] In step S5, the stroke x(n+1) of the high-speed mold opening process in the next casting (n+1th casting) is set to x(n) - Δx(n), and the control is terminated. In step S5, for example, the control means 100 sets x(n+1) to a value obtained by subtracting the difference Δx(n) calculated in step S4 from the stroke x(n) used in the current casting. By feeding back the difference Δx(n) from the target value in the current casting to the next casting and bringing the stopping position of the movable mold 22 closer to the target value, the distance between the movable mold 22 and the fixed mold 21 at the completion of mold opening is prevented from becoming excessively close or far apart.

[0040] [Distance between molds at completion of mold opening] If the movable mold 22 and the fixed mold 21 are too far apart at the completion of mold opening, this will lead to an increase in the stroke during the mold opening process or mold clamping process, thereby extending the time required for one casting (cycle time).

[0041] Furthermore, if the molds are spaced apart by a large distance, spraying the release agent requires separate spraying onto both the movable mold 22 and the fixed mold 21, which is cumbersome. For example, a procedure is required in which a spray of the release agent enters the mold, sprays the release agent onto the fixed mold 21, and then moves the spray to the vicinity of the movable mold 22 to spray the release agent again, which hinders the shortening of the casting cycle. It is also possible to provide a plurality of sprayers of the release agent (providing a plurality of sprayers that are independently driven) to spray the release agent onto the fixed mold 21 and the movable mold 22, respectively, but this would result in a complex equipment configuration.

[0042] Therefore, excessive spacing between the molds is not desirable, but conventionally, a physical stopper was provided to stop the movable mold 22, which resulted in the movable mold 22 moving more than necessary when the mold opening process was completed, and the distance between the molds became larger than necessary. On the other hand, if the molds are too close to each other when mold opening is completed, there is a risk that the distance required for removing the product and spraying the mold release agent cannot be secured.

[0043] In contrast, in the present application, by setting a target value for the position of the movable mold 22 at the completion of mold opening and performing control, the movable mold 22 (movable platen) and the fixed mold 21 (fixed platen) are prevented from being separated excessively. This reduces the amount of movement in both the mold clamping and mold opening processes, thereby shortening the cycle time. Furthermore, because the distance between the movable mold 22 and the fixed mold 21 is not greater than necessary, the release agent can be sprayed onto both the fixed mold 21 and the movable mold 22 in a single spray, further shortening the cycle. For example, by using a single spray device capable of spraying the release agent in two opposite directions (forward and backward), the release agent can be sprayed onto both the fixed mold 21 and the movable mold 22 in a single spray.

[0044] On the other hand, by setting the target value, the movable mold 22 (movable platen) and the fixed mold (fixed platen) do not come too close to each other, so that the distance between the molds necessary for removing the product and spraying the release agent can be secured. Note that the target stop position of the movable mold 22 can be set arbitrarily, so that the target value can be set at a position where the distance between the molds appropriate for removing the product and spraying the release agent can be secured while minimizing the distance between the molds when mold opening is complete, or it can be set at another position depending on the purpose of casting.

[0045] [Modification] In FIG. 3 , the difference between the stroke of the high-speed mold opening step of the current casting and the difference Δx(n) is used as the stroke of the high-speed mold opening step of the next casting. However, other calculation methods may be used. For example, a predetermined threshold value may be set for the difference Δx(n), and the stroke of the high-speed mold opening step may be corrected when a predetermined number of consecutive castings (mold openings) exceed the threshold value. Specifically, if three consecutive castings exceed the threshold value, the average value of the differences Δx(n) for those three castings is calculated, and the stroke of the next high-speed mold opening step is calculated based on this average value. If three consecutive castings fall below the threshold value, the average value of the differences Δx(n) for those three castings may be calculated, and the stroke of the next high-speed mold opening step may be calculated based on this average value. Alternatively, an upper and lower limit may be set for the threshold value of the difference Δx(n), and the average value may be calculated and corrected if the difference Δx(n) falls outside this range a predetermined number of times in a row. On the other hand, correction may also be performed even if the difference Δx(n) does not fall outside the threshold range consecutively, but only once.

[0046] Furthermore, the correction based on the average value of the differences over a predetermined number of times (e.g., three times) as described above may be combined with the method of performing correction for each casting as shown in the flowchart of Figure 3. When there is no risk of product deformation, the stroke in the mold release process may be adjusted based on the difference Δx(n) instead of or in addition to the high-speed mold opening process. Furthermore, when there is no need to consider the hydraulic pressure shock due to sudden deceleration, the stroke in the deceleration process may be adjusted based on the difference Δx(n) instead of or in addition to the high-speed mold opening process.

[0047] [Summary and Supplementary Information of Control Steps] The control means 100 corrects the stroke of the movable mold 22 (stroke of the mold opening means 30) based on the difference Δx between the target value and the actual value of the stop position of the movable mold 22 at the completion of mold opening. The control means 100 corrects the stroke of the movable mold 22 at the next mold opening, for example, based on the difference Δx at the current (nth) mold opening, during at least a part of the operating period of the die casting machine 1. In one example, when correcting the stroke of the movable mold 22 at the next mold opening, the control means 100 sets the stroke of the movable mold 22 at the next mold opening to a different value.

[0048] The control means 100 may repeatedly correct the stroke of the movable mold 22 at the next mold opening based on the difference Δx at the current mold opening during an initial period of the operating period of the die-casting machine 1. The control means 100 may terminate the correction for each mold opening (casting) when the difference Δx becomes sufficiently small to a level at which it can be evaluated that the actual stop position substantially matches the target stop position (i.e., when the difference Δx becomes equal to or smaller than a predetermined threshold value). Note that the initial period may be defined as the period until the difference Δx becomes sufficiently small.

[0049] The control means 100 may correct the stroke of the movable mold 22 if the difference Δx between multiple consecutive mold openings satisfies a predetermined condition during a period after the initial period of the operating period of the die casting machine 1. If the difference Δx between multiple consecutive mold openings does not satisfy the predetermined condition, the control means 100 may not correct the stroke of the movable mold 22. It may be determined that the predetermined condition is met if the difference Δx exceeds a threshold value for a predetermined number of consecutive mold openings (e.g., three times) or if the difference Δx falls below the threshold value for a predetermined number of consecutive mold openings. By correcting the stroke for each mold opening at the beginning of the operating period and then correcting the difference Δx between multiple mold openings (casting) if the difference Δx satisfies a certain condition thereafter, efficient stroke correction can be achieved. One of the various examples described above may combine at least some of the features described in the other examples.

[0050] [Effects] The effects obtained by the following configurations [1] to [5] are exemplified below.

[0051] [1] In a molding machine (die-casting machine 1) comprising a mold 20 (a fixed mold 21 and a movable mold 22), a mold opening means 30 driven by hydraulic pressure to open the mold 20, and a control means 100 to control the position of the mold 20 via the mold opening means 30, the control means 100 corrects the stroke of the movable mold 22 based on the difference Δx(n) between the target value and the actual value of the position of the movable mold 22 at the time of completion of mold opening.

[0052] [2] In the configuration of [1] above, the control means 100 corrects the stroke of the movable mold 22 at the next mold opening based on the difference Δx(n) at the current mold opening during at least a part of the operating period of the molding machine (die-casting machine 1).

[0053] [3] In the configuration of [1] or [2] above, the control means 100 repeatedly corrects the stroke of the movable mold 22 at the next mold opening based on the difference Δx(n) at the current mold opening during an initial period of the operating period of the molding machine (die-casting machine 1), and the control means 100 corrects the stroke of the movable mold 22 when the difference Δx at multiple consecutive mold openings satisfies a predetermined condition during a period after the initial period of the operating period of the molding machine (die-casting machine 1).

[0054] [4] In any one of the configurations [1] to [3] above, the control means 100 executes, in one mold opening, mold release control that moves the movable mold 22 by a predetermined first stroke, high-speed mold opening control that moves the movable mold 22 by a set stroke at a higher speed than the mold release control, and deceleration control that moves the movable mold 22 by a predetermined second stroke while reducing the speed compared to the high-speed mold opening control, wherein the sum of the first stroke, the set stroke, and the second stroke is smaller than the target stroke corresponding to the target value of the mold position at the completion of mold opening, and the control means 100 corrects the stroke of the movable mold 22 by changing the set value of the set stroke.

[0055] [5] A control method for a molding machine (die-casting machine 1) equipped with a hydraulically driven mold opening means, the control method including a control step of controlling the position of the movable mold 22 via the mold opening means 30 when the mold opening means 30 opens the mold 20 (fixed mold 21 and movable mold 22), and in the control step, correcting the stroke of the movable mold 22 based on the difference between the target value and the actual value of the position of the movable mold 22 at the time of completion of mold opening.

[0056] Because the movable mold 22 is hydraulically driven, there is often a discrepancy between the target stop position (target value) and the actual stop position (actual value). Therefore, by calculating the difference Δx(n) between the target and actual stop position values ​​for the nth casting, and performing feedback control to correct the stroke of the high-speed mold-opening step during the next casting (n+1th casting) based on this difference Δx(n), it is possible to bring the stop position of the movable mold 22 closer to the target value. This prevents the distance between the movable mold 22 and the fixed mold 21 from becoming too far away or too close, thereby shortening the cycle time while ensuring the distance between the molds necessary for product removal and release agent application.

[0057] The difference Δx calculated in the present invention may be used for other control purposes, such as correction of the chuck position when removing a product.

[0058] REFERENCE SIGNS LIST 1 Die casting machine 10 Injection device 20 Mold 22 Movable mold 30 Mold opening means 100 Control means

Claims

1. A molding machine comprising a hydraulically driven mold opening means for opening a mold, and a control means for controlling the mold position via said mold opening means, wherein said control means corrects the stroke of said mold based on the difference between the target value and actual value of said mold position at the completion of said mold opening.

2. The molding machine according to claim 1, characterized in that the control means corrects the stroke of the mold when the next mold is opened based on the difference at the current mold opening, for at least part of the operating period of the molding machine.

3. The molding machine according to claim 2, wherein the control means, during an initial period of the operating period of the molding machine, repeatedly corrects the stroke of the mold when the next mold is opened based on the difference when the current mold is opened, and the control means, during a period after the initial period of the operating period of the molding machine, corrects the stroke of the mold when the difference between multiple consecutive mold openings satisfies a predetermined condition.

4. The molding machine according to any one of claims 1 to 3, wherein the control means executes, in one mold opening, mold release control which moves the mold by a predetermined first stroke, high-speed mold opening control which moves the mold by a set stroke at a higher speed than the mold release control, and deceleration control which moves the mold by a predetermined second stroke while reducing the speed compared to the high-speed mold opening control, wherein the sum of the first stroke, the set stroke, and the second stroke is smaller than a target stroke corresponding to a target value for the mold position at the completion of the mold opening, and the control means corrects the stroke of the mold by changing the set value of the set stroke.

5. A control method for a molding machine equipped with a hydraulically driven mold opening means, comprising a control step of controlling the mold position via said mold opening means when opening the mold with said mold opening means, wherein said control step corrects the stroke of said mold based on the difference between the target value and actual value of said mold position at the completion of said mold opening.

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