JP2017087526A - Injection molding machine and control method of injection molding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an injection molding machine in which two or more molding dies are successively provided in a mold opening and closing direction and mold thickness size can be set to an appropriate value.SOLUTION: An injection molding machine 11 in which two or more molding dies A and B are successively provided in a mold opening and closing direction, comprises: mold thickness measuring means 26 and 27 measuring mold thickness dimensions of respective molding dies directly or indirectly; mold thickness correction means 43 which can correct individually the mold thickness dimensions t1 and t2 of the respective molding dies A and B measured by the mold thickness measuring means 26 and 27; and storing means 44 storing the corrected mold thickness dimensions t1a and t2b.SELECTED DRAWING: Figure 1

Description

The present invention relates to an injection molding machine and a method for controlling an injection molding machine.

When the molding die is replaced in the injection molding machine, the mold thickness dimension of the molding mold is measured, and the measured recording thickness dimension is stored in the storage means, and the mold opening / closing control of the injection molding machine during molding, etc. Used for. However, as the molding time by the injection molding machine becomes longer, the molding die is heated and thermally expanded, so that an error is generated from the mold thickness dimension measured in advance. For this reason, as in Patent Document 1, a mold thickness correcting means for correcting the mold thickness dimension stored in the mold thickness storage means based on the position of the movable mold detected by the mold position detecting means is provided. Further, Patent Document 1 describes that a mold thickness correction amount is obtained for each appropriate number of mold clamping operations every several or several times in the mold clamping device body. However, Patent Document 1 does not describe any correction of the mold thickness dimension in an injection molding machine in which two or more molding dies are continuously provided in the mold opening / closing direction. Further, Patent Document 1 does not describe anything about the correction of the mold thickness when using a mold in which a spring is compressed when the mold is closed.

On the other hand, Patent Document 2 describes the detection and control of the mold thickness of an injection molding machine in which two or more molding dies are connected in the mold opening / closing direction. However, Japanese Patent Laid-Open No. 2004-228688 stops the rotating disk at an arbitrary position according to the thickness of the mold to be used, and the mold thickness adjusting mechanism according to the thickness of the mold (the total thickness of each mold). Only the adjustment of the position of the rear platen is described, and there is no description about correction of the mold thickness dimension.

JP-A-7-148740 (Claims 1, 0028, FIG. 1, FIG. 4) JP 2011-31535 A (Claims 1, 0023, 0026, FIG. 1)

However, in the case of an injection molding machine in which two or more molding dies are connected in the mold opening / closing direction, the structure of the two or more molding dies or a mold opening / closing means for opening / closing the two or more molding dies is provided. The structure and operation are rarely the same. Under such circumstances, how to set the mold thickness dimension of two or more molding dies to an appropriate value is an important problem.

In view of the above problems, the present invention provides an injection molding machine capable of setting the mold thickness dimension to an appropriate value in an injection molding machine in which two or more molding dies are connected in the mold opening / closing direction. The purpose is to do.

The injection molding machine according to claim 1 of the present invention is an injection molding machine in which two or more molding dies are continuously arranged in the mold opening / closing direction, and the mold thickness dimensions of the respective molding dies directly or indirectly. A mold thickness measuring means for measuring the mold thickness, a mold thickness correcting means capable of individually correcting the mold thickness dimension of each molding die measured by the mold thickness measuring means, and storing the corrected mold thickness dimension And a storage means.

The injection molding machine according to claim 2 of the present invention is characterized in that in claim 1, at least one molding die to which a spring is compressed when the mold is closed is attached.

An injection molding machine according to claim 3 of the present invention is characterized in that in claim 2, a storage means for storing a correction value corresponding to a molding die in which a spring is compressed when the mold is closed is provided. To do.

According to a fourth aspect of the present invention, there is provided a method for controlling an injection molding machine according to a control method for an injection molding machine in which two or more molding dies are continuously arranged in the mold opening / closing direction. The mold thickness dimension of the mold is measured, the measured mold thickness dimension is individually corrected, and the corrected mold thickness dimension is used for control.

According to a fifth aspect of the present invention, there is provided a method for controlling an injection molding machine according to the fourth aspect, wherein a positive correction value of a mold thickness dimension of at least one molding die is set to a positive value of a mold thickness dimension of another molding mold. It is characterized by having a correction value or more.

The injection molding machine of the present invention is an injection molding machine in which two or more molding dies are continuously arranged in the mold opening / closing direction, and a mold thickness measurement that directly or indirectly measures the mold thickness dimension of each molding dies. Means, a mold thickness correcting means capable of individually correcting the mold thickness dimension of each molding die measured by the mold thickness measuring means, and a storage means for storing the corrected mold thickness dimension. Therefore, the mold thickness dimensions of two or more molding dies arranged continuously in the mold opening / closing direction can be set to appropriate values, and more accurate control can be performed during molding.

It is a top view of the injection molding machine of this embodiment of this invention, Comprising: It is a figure which shows the state at the time of a mold opening. It is a top view of the injection molding machine of this embodiment of this invention, Comprising: It is a figure which shows the state at the time of a mold closing (at the time of mold thickness measurement). It is a flowchart figure of the control method of the injection molding machine of this invention. It is the schematic which shows another control method of the injection molding machine of this invention. It is the schematic which shows the injection molding machine of another embodiment of this invention. It is the schematic which shows the injection molding machine of another embodiment of this invention.

An injection molding machine 11 according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. The injection molding machine 11 is an injection molding machine in which two or more molding dies A and B are continuously provided in the mold opening / closing direction. A mold clamping device 13 is disposed on the upper surface of the bed 12. The mold clamping device 13 moves in the mold opening / closing direction between the movable platen 15 to which the movable mold 14 is attached and movable in the mold opening / closing direction and the fixed platen 16 to which the fixed die 16 is fixedly provided. A free intermediate member 19 is provided. A rotating plate 20 constituting a part of the intermediate member 19 is rotatably attached, and intermediate molds 18 and 18 are attached to both surfaces of the rotating plate 20, respectively. When the mold is closed and when the mold is clamped, the fixed mold 16 and one of the intermediate molds 18 form a fixed mold A, and the movable mold 14 and the other of the intermediate molds 18 move the movable mold. A molding die B is formed. The molding die A is not always formed by the same intermediate die 18 and the fixed die 16 because the intermediate die 18 is inverted together with the 180 ° reversal of the turntable 20 when the intermediate die 18 is molded. A mold 18 is also formed. Further, the molding die B is not always formed by the same intermediate mold 18 and the movable mold 14, but is also formed by different intermediate molds 18.

In the vicinity of the four corners of the fixed platen 17, mold clamping cylinders 22 that are operated by hydraulic pressure as mold clamping means 21 are provided, and the rods of the mold clamping cylinders 22 constitute tie bars 23. The tie bar 23 is also inserted through the movable platen 15 and the intermediate member 19. Further, a half nut 24 is provided in the vicinity of the insertion portion of the tie bar 23 on the outer side surface of the movable platen 15 so as to be locked to a locking portion 25 provided on the tie bar 23. The arrangement of the mold clamping means 21 is not limited to this, and a mold clamping cylinder provided on the movable platen 15 side or a toggle mechanism may be used.

The injection molding machine 11 also opens and closes a mold opening / closing means 26 for moving the movable platen 15 (including the movable mold 14) in the mold opening / closing direction, and an intermediate member 19 (including the intermediate molds 18, 18 and the rotating plate 20). A mold opening / closing means 27 for moving in the direction is provided. The movable plate mold opening / closing means 26 (movable mold mold opening / closing means) includes a drive shaft of a servo motor 28 fixed on the bed 12 and a ball screw 29 pivotally supported on the bed 12 via a belt or the like. Are connected. The servo motor 28 is provided with a rotary encoder 31.

A ball screw nut 33 is fixed to a bracket on the side surface of the movable platen 15, and a ball screw 29 is inserted into the ball screw nut 33. The servo motor 28 is connected to a control device 35 that controls the entire injection molding machine 11 via a servo amplifier 34. The mold opening / closing means 26 of the movable plate including the servo motor 28 and the rotary encoder 31 capable of detecting the position of the movable plate 15 with respect to the bed 12 or the fixed plate 17 also constitutes the mold thickness measuring unit of the present invention. 1 and 2, only one movable plate mold opening / closing means 26 is shown, but generally two to four groups are provided.

As for the mold opening / closing means 27 (middle mold opening / closing means) of the intermediate member for opening and closing the mold between the movable platen 15 and the intermediate member 19, a servo motor 36 is fixed to the bracket on the side surface of the movable platen 15, and the intermediate member A ball screw nut 37 is fixed to the ball screw nut 19, and a ball screw 38 inserted through the ball screw nut 37 is connected to the drive shaft of the servo motor 36. The servo motor 36 is provided with a rotary encoder 39. The servo motor 36 is connected to a control device 35 that controls the entire injection molding machine 11 via a servo amplifier 40. The mold opening / closing means 27 of the intermediate member including the servo motor 36 and the rotary encoder 39 capable of detecting the position of the intermediate member 19 also constitutes the mold thickness measuring means of the present invention. 1 and 2, only one intermediate member mold opening / closing means 27 is shown, but generally two to four groups are provided. It should be noted that the method of connecting the plate and bed to which the mold opening / closing means 26 of the movable plate 26 and the mold opening / closing means 27 of the intermediate member are attached, the drive shafts of the servo motors 28 and 36, and the ball screws 29 and 38 are not limited thereto. The servo motors 28 and 36 may be provided with an electromagnetic brake.

A first injection device 41 is provided on the bed 12 outside the fixed platen 17, and a second injection device 42 that moves together with the movable platen 15 is provided outside the movable platen 15. The control device 35 performs overall control of the injection molding machine 11, but in the part relating to the correction of the mold thickness dimension of the present invention, the mold thickness dimension t1 of the respective molding dies A and B measured by the mold thickness measuring means. , T2 and a mold thickness correcting means 43 capable of individually correcting the mold thickness dimensions t1 and t2, and a storage means 44 for storing the corrected mold thickness dimensions t1a and t2b. The control device 35 is connected to the setting screen 45.

Next, a control method of the injection molding machine 11 will be described. The injection molding machine 11 measures the mold thickness dimensions of the fixed-side mold A and the movable-side mold B before starting molding (especially the first time), and uses it for control. More specifically, the control origin of the mold opening / closing means 26 of the movable platen is determined by measuring and setting the mold thickness dimensions of the molding die A and the molding die B, and the mold closing of the movable platen 15 is performed based on the control origin. A completion position, a mold protection start position, a mold opening / closing speed changing position, a mold opening completion position, and the like are set. For the intermediate member 19, the control origin of the mold opening / closing means 27 of the intermediate member is determined, and the mold closing completion position of the intermediate member, the mold protection start position, the mold opening / closing speed change position, the mold opening are determined based on the control origin. The completion position is set. Therefore, it is very important to accurately set the mold thickness dimensions of the mold A and the mold B.

However, in the case of the injection molding machine 11 in which two or more molding dies A and B are continuously provided in the mold opening / closing direction, the mold opening / closing means 27 of the intermediate member and the mold opening / closing means 26 of the movable plate are mutually connected. Since the structure of the molding die A and the molding die B and the structure and operation of the mold opening / closing means 27 of the intermediate member and the mold opening / closing means 26 of the movable plate are different, respectively. It is difficult to accurately measure the mold thickness dimensions of the mold B individually. The determination of the completion of mold closing at the time of mold thickness measurement is performed by the servo motors 28 and 36 of the mold opening / closing means when the movable mold 14 and the intermediate mold 18 and the fixed mold 16 and the intermediate mold 18 are in contact with the mold, respectively. Since the torque is detected, it is accurate when a load is generated on the ball screws 29 and 38 when it is determined that the mold closing is completed, and the mold A and the mold B are compressed. There is also a problem of affecting the mold thickness measurement.

Next, a specific procedure for mold thickness measurement and mold thickness correction will be described with reference to the flowchart of FIG. First, in the storage means 44 of the control device 35 of the injection molding machine, the correction value a (offset value) of the mold thickness dimension of the molding die A and the correction value b (offset value) of the mold thickness dimension of the molding die B are stored in advance. Saved. As described above, the correction values a and b (offset values) of the mold thickness dimensions of the molding die A and the molding die B are the elongations of the ball screws 29 and 38 for opening and closing the die, the molding die A, and the molding die B. In normal cases, positive correction values a and b (offset values) are stored. However, as a modification, the correction values a and b (offset values) of the mold thickness dimensions of the molding die A and the molding die B may be individually set by the operator from the setting screen. Further, the case where the same correction value is used as a result is also included in the present invention. Furthermore, the present invention includes a case where any of the mold thickness dimensions t1 and t2 is not corrected. The individual correction values a and b (offset values) of the fixed mold and movable mold thickness dimensions may be incorporated from the time of shipment.

When the molding die A and the molding die B of the injection molding machine 11 are replaced with the first molding die, the mold thickness dimension is always measured. Then, the measured mold thickness dimension (including the corrected mold thickness dimension) is stored in the storage means 44 and used in the next molding. When the mold of the injection molding machine 11 is replaced with the molding mold A and the molding mold B at a later date, the mold thickness dimension measured last time is stored in the storage means 44, so the mold thickness dimension is measured. You may, but it is not necessary.

The mold thickness dimension is measured after the molding die A and the molding die B are attached to the stationary platen 17, the rotating plate 20 of the intermediate member 19, and the movable platen 15, and before molding including semi-automatic molding is started. First, the description starts from a state in which the intermediate member 19 and the intermediate molds 18 and 18, the movable platen 15, and the movable mold 14 are in the mold opening completion position. The operator inputs the mold closing switch on the setting screen 45 (s1) to start the automatic mold thickness adjustment mode. Then, the servo motor 28 of the mold opening / closing means 26 of the movable plate and the servo motor 36 of the mold opening / closing means 27 of the intermediate member start operation (s2), and the movable plate 15 and the movable mold 14 are moved to the intermediate member 19 and the intermediate mold. It is moved toward the mold 18,18. At this time, the servo motor 36 of the mold opening / closing means 27 of the intermediate member operates in a direction to reduce the distance between the movable platen 15 and the intermediate member 19. At this time, the position of the intermediate member 19 with respect to the fixed platen 17 is not changed. Then, the determination of the mold contact between the movable mold 14 and the intermediate mold 18 is made by detecting the torque limit value in which the torque of the servo motor 36 is set (s3). The servo motor 36 is made servo-free (s4).

Next, the servo motor 28 of the mold opening / closing means 26 of the movable plate is started again (s5), and the movable plate 15, the movable mold 14, the intermediate member 19, and the intermediate molds 18, 18 are replaced with the fixed plate 17 and the fixed mold. It is moved toward the mold 16. The determination of the mold contact between the fixed mold 16 and the intermediate mold 18 (on the fixed mold side) is made when the torque of the servo motor 28 senses the torque limit value (s6). When it is determined that the fixed mold 16 and the intermediate mold 18 are in contact with each other, the detection value of the rotary encoder 39 of the servo motor 36 of the mold opening / closing means 27 of the intermediate member which is the mold thickness measuring means is read next. The position of the intermediate member 19 relative to the movable platen 15 is detected (s7). Then, the measured value of the mold thickness dimension t2 (movable side mold thickness) of the molding die B is calculated from the position of the intermediate member 19 with respect to the movable platen 15 (s8). Therefore, the measurement of the mold thickness dimension of the molding die B is performed directly. Further, the detection value of the rotary encoder 31 of the servo motor 28 of the mold opening / closing means 26 of the movable plate which is the mold thickness measuring means is read to detect the position of the movable plate 15 relative to the fixed plate 17 (s9). The mold thickness dimension of the molding die B is subtracted from the position of the movable platen 15 with respect to the fixed platen 17 to calculate the measured value of the mold thickness dimension t1 (fixed side mold thickness) of the molding die A (s10). Therefore, the measurement of the mold thickness dimension of the molding die A is performed indirectly.

Next, using the correction value b (offset value) of the mold thickness dimension of the molding die B preset and stored in the storage means 44, the mold thickness dimension of the molding mold B is corrected by the mold thickness correction means 43 (s11). ). Then, the corrected mold thickness dimension t2b of the molding die B is stored in the storage means 44 (s12). Further, using the correction value a (offset value) of the mold thickness dimension of the molding die A preset and stored in the storage means, the mold thickness correction means 43 corrects the fixed-side mold thickness dimension (s13), and after correction The mold thickness dimension t1a of the molding die A is stored in the storage means 44 (s14). Although not limited to this, in the present embodiment, a corrected mold thickness dimension t2b is obtained by adding a positive correction value b to the measured mold thickness dimension t2 of the molding die B. Further, a corrected mold thickness dimension t1a is obtained by adding a positive correction value a equal to or larger than the correction value b of the molding mold B to the measured mold thickness dimension t1 of the molding mold A. The reason why the correction value a on the side of the molding die A is set to be equal to or larger than the correction value b of the molding die B (or larger than the correction value b) is that the length of the ball screw 29 of the mold opening / closing means 26 of the movable platen. The length is longer than the length of the ball screw 38 of the mold opening / closing means 27 of the intermediate member and is likely to be stretched. When measuring the mold thickness dimension, the measured value of the mold thickness dimension t1 of the mold A is the molding mold. This is because the measured value of the mold thickness dimension t2 of B tends to be measured smaller than the actual mold dimension. However, the correction value a on the mold A side and the correction value b on the mold B may be the same value. The corrected mold thickness dimensions t1a and t2b stored in the storage means 44 are used for controlling the molding cycle of the injection molding machine 11 as described below. However, in the case where there is a problem by performing molding with the corrected mold thickness dimensions t1a and t2b, the correction value a and the correction value b may be changed, and the mold thickness dimensions t1a and t2b used for control may be changed again.

Next, the control of the molding cycle of the injection molding machine 11 after setting the mold thickness dimensions t1a and t2b will be described. In the mold closing process of the injection molding machine 11, the servo motor 36 of the mold opening / closing means 27 of the intermediate member 19 and the movable plate 15 are moved from the state in which the fixed mold 16, the intermediate molds 18, 18 and the movable mold 14 are opened. When the servo motor 28 of the mold opening / closing means 26 is actuated, based on the corrected mold thickness dimension t2b of the molding die B and the corrected mold thickness dimension t1a of the molding mold A stored in the storage means 44, The intermediate molds 18 and 18 and the movable mold 14 are moved by closed loop control to the respective mold closing completion positions. Needless to say, the positions at which the mold opening / closing speed changes and the mold protection start position are controlled by reading the detection values of the rotary encoders 31 and 39 of the servo motors 28 and 36. Then, the mold closing of the molding die A by the fixed mold 16 and the intermediate mold 18 and the mold closing of the molding die B by the intermediate mold 18 and the movable mold 14 are completed almost simultaneously.

With the movable platen 15 stopped at the mold closing completion position when the mold clamping process is started, the locking teeth of the half nut 24 of the movable platen 15 are locked to the locking portion 25 of the tie bar 23, and then the mold clamping cylinder. 22 is operated to clamp the mold A and the mold B. When the mold clamping is completed, an injection process is started, and the primary injection resin is injected from the first injection device 41 to the molding die A, and the secondary molding is performed from the second injection device 42 to the molding die B. (In this case, the previous primary molded product remains in the cavity of the molding die B, and the resin is added and bonded by secondary molding. The cooling process is performed for a predetermined time. When the cooling process is completed, the mold A or the mold B is released (strong mold opening process) using the clamping cylinder 22. In the next mold opening process, the movable plate is opened and closed. The servo motor 28 of the means 26 and the servo motor 36 of the mold opening / closing means 27 of the intermediate member are operated to open the molds A and B. The intermediate molds 18 and 18 and the movable mold 14 are opened. When the mold opening completion position is reached, an unloading process is performed and unillustrated unloading As a result, the composite molded product that has been subjected to the secondary molding is taken out from one mold of the molding die B. Then, the rotating plate 20 is rotated 180 °, and the intermediate mold 18 to which the primary molded product is attached is the movable mold. Then, the next mold closing process is started again.

Next, another control method of the injection molding machine 11 of the present invention will be described with reference to FIG. The structure of the injection molding machine 11 used for another control method is the same as that shown in FIG. In another control method, the mold thickness dimension is measured by firstly opening and closing the movable plate from the state where the movable mold 14 and the intermediate molds 18 and 18 are in the mold opening completion position (the state of FIG. 4A). Only the servo motor 28 of the means 26 is operated, and the movable platen 15, the movable mold 14, the intermediate member 19, and the intermediate molds 18 and 18 are moved in the mold closing completion direction. At this time, the servo motor 36 of the mold opening / closing means 27 of the intermediate member is locked. When the contact of the intermediate mold 18 with the fixed mold 16 is detected (the state shown in FIG. 4B), the mold thickness dimension of the mold A is measured by the rotary encoder 31. Then, using the correction value a (offset value) of the molding die A preset and stored in the storage means 44, the die thickness dimension is corrected by the mold thickness correcting means 43, and the corrected mold thickness dimension of the molding die A is corrected. t1a is stored in the storage means 44.

Next, in a state where the servo motor 28 of the mold opening / closing means 26 of the movable plate is servo-locked, only the servo motor 36 of the mold opening / closing means 27 of the intermediate member is operated to move the intermediate member 19 and the intermediate molds 18, 18. Move toward the mold 14. When the mold contact between the movable mold 14 and the intermediate mold 18 is detected (the state shown in FIG. 4C), the mold thickness dimension of the molding mold B is measured by the rotary encoder 39. Then, using the correction value b (offset value) of the molding die B set and stored in advance in the storage unit 44, the mold thickness dimension is corrected by the mold thickness correcting unit 43, and the corrected mold thickness dimension of the molding die B is obtained. t2b is stored in the storage means 44. The corrected mold thickness dimension t1a of the molding die A and the corrected mold thickness dimension t2b of the molding die B are used for control during molding. In FIG. 4, the mold thickness dimension of the molding die A may be measured after the mold thickness dimension of the molding die B is measured first. Further, measurement, correction, and storage of the mold thickness dimension using the injection molding machine 11 may be performed by a method other than the above embodiment.

In the injection molding machine 11 of FIG. 1, both the molding die A and the molding die B are clamped at the same time without rotating the turntable 20 and the intermediate dies 18 and 18, and molding is performed from the first injection device 41. Only the mold A may be formed by injecting a molten resin only from the second injection device 42 to the molding mold B to form a single-color molded product. Further, as a modification of the injection molding machine 11, the intermediate member (intermediate disk) is not provided with a mechanism for rotating the intermediate mold, and the intermediate mold attached to one surface of the fixed mold and the intermediate member (always the same) The molding die A may be formed by the intermediate die), and the molding die B may be formed by the intermediate die (always the same intermediate die) attached to the movable die and the other surface of the intermediate member. In the case of the modification, the number of molding dies may be two or more.

Further, the present invention may be an injection molding machine in which two or more molds are connected in the mold opening / closing direction. As shown in FIG. 5, three molding dies C, D, E are arranged in the mold opening / closing direction. The injection molding machine 51 provided continuously may be used. In FIG. 5, a fixed mold 53 is attached to the fixed platen 52. Then, first intermediate molds 55 and 55 are attached to both surfaces of the first intermediate member 54 that can be turned 180 °. Further, second intermediate molds 57 and 57 are attached to both surfaces of the second intermediate member 56 that can be turned 180 °. A movable mold 59 is attached to the movable platen 58.

The first intermediate member 54 can be moved in the mold opening / closing direction by the first mold opening / closing mechanism 60, and the second intermediate member 56 can be moved in the mold opening / closing direction by the second mold opening / closing mechanism 61. 58 is movable in the mold opening / closing direction by the third mold opening / closing mechanism 62. The molds C, D, and E are closed by the operations of the first mold opening / closing mechanism 60, the second mold opening / closing mechanism 61, and the third mold opening / closing mechanism 62, respectively. In the embodiment of FIG. 5, the molds C, D, and E are clamped by a mold clamping mechanism (not shown). The injection molding machine 51 is also provided with a plurality of injection devices (not shown).

When measuring the mold thickness dimension, the first mold opening / closing mechanism 60, the second mold opening / closing mechanism 61, and the third mold opening / closing mechanism 62, which are the respective mold thickness measuring means, are used to form the molds C, D, Although the mold thickness dimension of E is measured, the initial mold thickness dimension may not be accurately performed due to the difference in the structure of the molding die and the mold opening / closing mechanism. Correction is possible. As for the correction of the mold thickness dimension, it may be possible to correct or not perform the correction, or it may be possible to set whether or not to correct. The corrected mold thickness dimension is stored in the storage means and used for control during molding.

Next, an injection molding machine 71 in which two or more molds of FIG. 6 according to the present invention are connected in the mold opening / closing direction will be described. The injection molding machine 71 is fixedly provided with a fixed platen 72 at the center, and the fixed platen 72 is provided with an intermediate plate 73 that rotates about a vertical axis. Intermediate molds 74 and 74 are attached to both surfaces of the intermediate plate 73, respectively. Further, on the left side in FIG. 6, a first movable plate 76 that is opened / closed by a first mold opening / closing mechanism 75 with respect to the fixed platen 72 is provided, and the first movable plate 76 has a first movable mold 77. Is installed. Further, on the right side in FIG. 6, a second movable plate 79 that is opened / closed by a second mold opening / closing mechanism 78 with respect to the fixed platen 72 is provided, and the second movable plate 79 has a second movable mold 80. Is installed. A mold clamping device (not shown) is provided, and at the time of mold clamping, one of the intermediate molds 74 and 74 and the first movable mold 77 constitute the molding mold F, and the other of the intermediate molds 74 and 74 is the other. The second movable mold 80 constitutes a molding mold G. In addition, an injection device (not shown) is provided outside each of the first movable plate 76 and the second movable plate 79.

Also in the injection molding machine 71, the position of the first movable plate 76 with respect to the fixed platen 72, the fixed platen by the rotary encoder of the servo motor (not shown) of the first mold opening / closing mechanism 75 and the second mold opening / closing mechanism 78 when the mold is closed. By detecting the position of the second movable platen 79 with respect to 72, the mold thicknesses of the molding die F and the molding die G can be measured. Since the measured mold thickness is different between the mold F and the mold G, the mold thickness is corrected by the mold thickness correcting means (one of the mold thickness is not corrected). Including cases)

Further, in an injection molding machine provided with a mold opening / closing mechanism having the same arrangement as the injection molding machine 71, 79 may be a fixed platen, 73 may be an intermediate member, and 76 may be a movable platen.

In the above injection molding machines 11, 51, 71, when the actuator of the mold opening / closing means is a hydraulic cylinder, the mold thickness measuring means for detecting the mold position and measuring the mold thickness dimension is a linear direction other than the rotary encoder. It may be a displacement sensor that can detect the position. Further, the distance between the surface of the fixed plate and the intermediate plate (rotary plate) or the intermediate plate (rotary plate) and the movable plate may be measured by a sensor such as a non-contact ultrasonic sensor or a laser sensor.

Further, in the injection molding machines 11, 51, 71, the molding die to be attached may be one in which at least one molding die (spring die) in which a spring is compressed when the die is closed is attached. In the case of a molding die in which the spring is compressed, a mold closing force larger than that of other molding dies is required when the mold is closed to the mold closing completion position by the mold opening / closing means. Therefore, a large set value is also required for a torque limit value for detecting the mold closing completion position. As a result, when the mold thickness is measured after the mold closing is completed, a larger load such as a ball screw is applied to cause elongation. As a result, the mold thickness dimension measured by the mold thickness measuring means is smaller than the actual value, and a relatively large correction value (offset value) is often required. The correction value c (offset value) corresponding to the molding die (spring die) whose spring is compressed when the die is closed may be stored in the storage unit 44 separately. Further, when a spring mold is further mounted at a position where correction values a and b (offset values) for the fixed mold and the movable mold of the injection molding machine 11 are set in advance, correction for the spring mold is performed. It is also assumed that the value c (offset value) is further added.

Further, in the injection molding machines 11 and 71, the mold thickness dimensions of the molding die A and the molding die B are measured and corrected twice, respectively, before the intermediate molds 18 and 74 are rotated by 180 °. It may be a thing. For example, in the injection molding machine 11, the intermediate molds 18 and 18 are manufactured to have the same thickness, but there may actually be a slight error or the like. The mold thickness dimension used for the control may be changed according to the number of times of molding and the number of times of molding.

In the present invention, as in Patent Document 1, in order to cope with thermal expansion of the mold during molding, the mold thickness dimension may be corrected even during the molding. The mold thickness dimension may be corrected by detecting the molding shot, molding time, mold temperature, etc., and the mold clamping force is detected by the torque of the servo motor for opening and closing the mold and the tie bar sensor. You may go.

The present invention is not enumerated one by one, but is not limited to that of the above-described embodiment, and it goes without saying that those skilled in the art also apply modifications made in accordance with the spirit of the present invention. is there. For injection molding, the material is not limited, and includes materials that perform molding such as injection compression molding, foam molding, sandwich molding, and insert molding. Further, the present invention may be a vertical injection molding machine or a press molding machine in which two or more molds are continuously provided in the vertical mold opening / closing direction.

11, 51, 71 Injection molding machine 13 Clamping device 14, 59, 77, 80 Movable die 15, 58, 76, 79 Movable platen 16, 53, Fixed die 17, 52, 72 Fixed platen 18, 55, 57 , 74 Intermediate molds 19, 57 Intermediate member 26 Mold opening / closing means (mold thickness measuring means) of movable platen
27 Mold opening / closing means (mold thickness measuring means) for intermediate member
22 Clamping cylinders 28, 36 Servo motor 43 Mold thickness correcting means 44 Storage means A, B, C, D, E, F, G Mold

Claims (5)

In an injection molding machine in which two or more molding dies are continuously provided in the mold opening and closing direction,
Mold thickness measuring means for directly or indirectly measuring the mold thickness dimension of each molding die;
Mold thickness correcting means capable of individually correcting the mold thickness dimension of each molding die measured by the mold thickness measuring means;
An injection molding machine comprising: storage means for storing the corrected mold thickness dimension. 2. The injection molding machine according to claim 1, wherein at least one molding die is attached to which a spring is compressed when the mold is closed. The injection molding machine according to claim 2, further comprising storage means for storing a correction value corresponding to a molding die whose spring is compressed when the mold is closed. In a control method of an injection molding machine in which two or more molding dies are continuously provided in the mold opening / closing direction,
When the mold is closed, measure the mold thickness of each mold,
A method for controlling an injection molding machine, wherein the measured mold thickness dimension is individually corrected, and the corrected mold thickness dimension is used for control. 5. The method of controlling an injection molding machine according to claim 4, wherein the positive correction value of the mold thickness dimension of at least one molding die is set to be equal to or greater than the positive correction value of the mold thickness dimension of other molding dies. .