JP2019111671A - Method for operating injection blow molding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an operation method of an injection injection molding machine capable of efficiently rotating an intermediate plate to efficiently carry out a molding cycle and without a problem of deterioration of mechanical parts such as a ball screw required for driving the intermediate plate. To do. SOLUTION: An injection blow molding machine (1) in which a mold plate device (2) is composed of a fixed plate (5), a movable plate (6), and an intermediate plate (8) provided between them and rotating in a reversible manner. It is configured as an operation method of. The fixed plate (5) is provided with an injection molding die (21), and the movable plate (6) is provided with a blow molding die (23A, 23a). A parison (40) is formed by injection molding. This is blow molded. The intermediate board (8) is rotated by an intermediate board rotation servomotor (38) provided with an encoder. The mold clamping of the mold plate device (2) makes the intermediate plate rotation servomotor (38) servo-free before the mold (21) touches. [Selection diagram] Fig. 3

Description

  The present invention relates to an operation method of an injection blow molding machine in which an injection molding machine for molding a parison by injection molding and a blow molding machine for molding a hollow molded product from the parison by blow molding are integrated.

  Most of hollow containers made of resin are molded by blow molding. The blow molding method uses, for example, a half mold. The mold is provided with a cavity for forming the outer side of the molded product, and the hollow mold or parison heated by the two halves of the mold is sandwiched, and air is blown into the inside of the parison. The parison is then expanded and forced into the cavity. That is, a hollow molded article is obtained. After the resin has cooled and solidified, the mold is opened and the hollow molded article is taken out. By the way, in parisons, there are pipe-like parisons that are extruded and come out in a so-called direct blow molding method, and there are parisons with bottoms. The bottomed parison can be molded by injection molding. A method of forming a parison by injection molding and blow molding the parison is called injection blow molding. Furthermore, when blow molding an injection molded parison immediately without cooling, it may be referred to as hot parison injection blow molding.

  Since the hot parison injection blow molding method uses the parison without cooling, in other words, since the parison is used without reheating, the waste of energy is small and excellent. An injection blow molding machine is known as an apparatus capable of efficiently performing the hot parison injection blow molding method. The injection blow molding machine is well known as described in, for example, Patent Document 1, and has a structure in which the injection molding machine and the blow molding machine are integrated.

Unexamined-Japanese-Patent No. 2006-35667

  Generally, an injection blow molding machine comprises a fixed platen, a movable platen, and an intermediate platen provided therebetween. The movable disc is driven by a mold opening and closing mechanism, and the intermediate disc is driven by a predetermined intermediate disc opening and closing mechanism. The fixed platen is provided with an injection molding die, and the nozzle of the injection device provided on the back surface of the fixed platen touches the sprue of the injection molding die. When the fixed platen and the intermediate platen are closed, a cavity for molding a parison is formed by the injection mold and a predetermined portion of the intermediate platen. On the other hand, the movable platen is provided with a two-piece blow molding die that slides on the movable platen. The intermediate plate and the movable plate are closed, and when the two halves of the blow molding die slide and integrate, a blow molding cavity is formed. In the injection blow molding machine, it is necessary to leave the parison obtained by injection molding on the intermediate plate and to move it to the opposite side of the intermediate plate in order to blow it. In the injection blow molding machine described in Patent Document 1, the intermediate board is provided with a rotary frame rotating with respect to the intermediate board and a molded article gripping device moved by the rotary frame, whereby injection molding is performed. A parison injection-molded between the mold and the intermediate plate is held by the molded article holding device, rotated by the rotary frame, and moved to the opposite side of the intermediate plate, ie, the movable side. However, in many injection blow molding machines, the intermediate plate rotates in reverse. In such an injection blow molding machine, the parison obtained by injection molding is left on the intermediate plate, and the parison can be moved to the opposite side of the intermediate plate simply by inverting the intermediate plate. In the injection blow molding machine, the hollow molded article is formed as follows. The intermediate disc and the fixed disc are closed by the intermediate disc opening / closing mechanism, and the movable disc is driven by the mold opening / closing mechanism to close the movable disc and the intermediate disc. When resin is injected from the injection device, a parison is formed in a cavity in an injection mold, which is closed between a fixed plate and an intermediate plate. The mold opening and closing mechanism is driven to open the movable disc and the intermediate disc opening and closing mechanism is driven to open the intermediate disc relative to the fixed disc. Then the parison remains on the middle board. Move the parison by rotating the middle board in reverse. Again, as described above, the intermediate plate and the fixed plate are closed, and the movable plate and the intermediate plate are closed. When the two halves of the blow molding die provided on the movable plate are slid and integrated, the parison is sandwiched between the blow molding dies. Blow molding is performed to form a hollow molded article. At this time, resin is injected from the injection device, and the next parison is molded in an injection mold. Open the movable plate and open the intermediate plate to the fixed plate to obtain a hollow molded article. The intermediate plate is rotated to move the injection molded parison to the opposite side. Hereinafter, it shape | molds similarly.

  The conventional injection blow molding machine can mold a resin hollow container by a hot parison injection blow molding method. As it can be carried out with a single machine from injection molding to blow molding, there is no concern of adhesion of dirt, and manufacturing efficiency is high. And since parisons can be blow molded without cooling, they are highly energy efficient. However, injection blow molding machines also have problems to be solved. In many injection blow molding machines, the intermediate plate rotates in reverse. In the case where the rotation of the intermediate disc is driven by a hydraulic motor, a plurality of sensors for detecting the rotational position of the rotary disc are required, which makes control difficult. In order to turn the rotating disc and stop at the correct reverse position, deceleration must be started from before the reverse position, and multiple sensors are required, and difficult control must be performed. It is. As a result, the cost of the control device and the like increases, and the cost for adjustment also increases. On the other hand, if the intermediate plate is rotated by a servomotor, it can be rotated to the reverse position with high accuracy. This is because the servomotor can control the rotation angle accurately by one encoder. In this case, adopting a servomotor is advantageous in terms of cost and is easy to control. However, although control by a servomotor is highly accurate, there is a problem that there is no play. Since there is no play, mechanical components such as ball screws are burdened at the time of mold clamping, and the mechanical components are deteriorated prematurely.

  An object of the present invention is to provide a method of operating an injection blow molding machine which solves the problems as described above, and more specifically, an intermediate plate is accurately rotated to efficiently carry out a molding cycle. It is an object of the present invention to provide a method of operating an injection blow molding machine which does not have the problem of deterioration of mechanical parts such as ball screws necessary for driving the intermediate plate.

  According to the present invention, in order to achieve the above object, a platen device is provided between a stationary platen, a movable platen which is opened and closed by a clamping mechanism, and the stationary platen and the movable platen to be reversely rotated. It is comprised as an operating method of the injection blow molding machine which consists of an intermediate board. A mold for injection molding is provided on the fixed platen, and a mold for blow molding is provided on the movable platen. A parison is formed by injection molding, and the parison is formed by blow molding. The intermediate disc is provided with an intermediate disc rotation servomotor provided with an encoder for detecting a rotational angle, and is thereby rotated. In the present invention, the mold clamping of the template device is configured to stop and control the control of the rotation angle by the intermediate disk rotating servomotor before the mold is touched. Further, the intermediate plate is adapted to be opened and closed with respect to the movable plate or the fixed plate by an intermediate plate opening / closing mechanism consisting of a predetermined ball screw mechanism and a servomotor for opening / closing the intermediate plate. The mold clamping of the mold machine is performed by stopping the control by the servomotor for opening / closing the intermediate board before the mold touches.

Thus, in order to achieve the above object, according to the first aspect of the present invention, in order to achieve the above object, a die apparatus is provided between a fixed board, a movable board which is opened and closed by a mold clamping mechanism, and the fixed board and the movable board. The fixed platen is provided with an injection molding die and the movable platen is provided with a blow molding die, the mold assembly is clamped, and the resin is injected from the injection device. Then, a parison is molded in the injection mold, and when the mold is opened, the parison is left on the intermediate plate, and the intermediate plate is reversely rotated to make the parison of the intermediate plate face the movable plate, A method of operating an injection blow molding machine in which a hollow molding is formed from a parison by clamping a mold and blow molding using the blow molding die, wherein the intermediate plate has a rotation angle of Encoder to detect A servomotor for rotating the intermediate plate is provided, and it is rotated by this, and the mold clamping of the die device is controlled by the servomotor for rotating the intermediate plate before the mold touches. A method of operating an injection blow molding machine comprising:
According to a second aspect of the present invention, in the method of operating an injection blow molding machine according to the first aspect, the intermediate disc is formed of a predetermined ball screw mechanism and an intermediate disc opening / closing servomotor on the movable disc or the fixed disc. An intermediate plate opening and closing mechanism is provided to open and close the mold with respect to the movable plate or the fixed plate, and the mold clamping of the template device is performed before the intermediate plate is opened and closed by the mold. It is configured as an operation method of an injection blow molding machine characterized by stopping control by a servomotor for driving.

  As described above, the present invention is configured as an operation method of an injection blow molding machine. The target injection blow molding machine is composed of a fixed platen, a movable platen that is opened and closed by a clamping mechanism, and an intermediate platen provided between the fixed platen and the movable platen. The injection molding mold is provided on the movable plate respectively for the blow molding mold, and the mold unit is clamped, and when resin is injected from the injection apparatus, a parison is formed in the injection molding mold, and the mold is opened. Then, the parison is left on the intermediate plate, and the intermediate plate is turned in reverse to make the parison of the intermediate plate face the movable plate, the mold unit is clamped, and blow molding is performed using the blow molding die. A hollow molded article is to be molded. The intermediate disc is provided with an intermediate disc rotation servomotor provided with an encoder for detecting the rotational angle, and is thereby rotated. In the present invention, the mold clamping of the template device is configured to stop the control of the rotation angle by the servomotor for rotating the intermediate disk before the mold is touched. That is, the servomotor for rotating the intermediate board is clamped in a so-called servo free state. During mold clamping, a force will be applied to the intermediate plate, and if control of the rotation angle is performed on the intermediate plate rotation servomotor, a strong load may be applied to the intermediate plate rotation servomotor, but servo free As it is in the condition, no load is applied to the servomotor for rotating the intermediate board. There is no risk of deterioration since the intermediate disc rotating servomotor and the mechanical structure for transmitting the rotation are not burdened. According to another invention, the intermediate board is provided with an intermediate board opening / closing mechanism consisting of a predetermined ball screw mechanism and a servomotor for opening / closing the intermediate board on the movable board or fixed board, whereby mold opening / closing is performed with respect to the movable board or fixed board It is supposed to And, the mold clamping of the mold machine is configured to be performed while stopping the control by the servomotor for opening and closing the intermediate board before the mold touches. In other words, the intermediate plate opening / closing servomotor is clamped in a servo free state. As a result, it is possible to prevent the load not only on the intermediate board opening / closing servomotor but also on the ball screw mechanism, and to prevent them from being deteriorated.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows typically the injection blow molding machine which concerns on embodiment of this invention, The (A) is the injection blow molding in the state which the (A) closed in the state where the mold apparatus was opened. It is a front view of a machine. FIG. 6 schematically illustrates a method of molding a hollow molded article in the injection blow molding machine according to the embodiment of the present invention, wherein (a) to (g) are parts of the injection blow molding machine in respective steps It is a front view showing. It is a flowchart which shows the operation method in the injection blow molding machine which concerns on embodiment of this invention, The (a) is each at the time of mold clamping, (i) at the time of mold opening and reversing an intermediate board. It is a flowchart which shows a driving method.

  Hereinafter, the present embodiment will be described. The injection blow molding machine 1 according to the present embodiment is, as shown in (A) and (A) of FIG. 1, high-pressure air not shown in the figure, the template apparatus 2, the injection apparatus 3. It roughly comprises a supply device. The platen device 2 is provided between the fixed platen 5 fixed to the bed, the movable platen 6 that slides with respect to the bed to be opened and closed by the mold, and the fixed platen 5 and the movable platen 6 It comprises an intermediate plate 8 adapted to slide relative to a bed, a clamping housing 10, four tie bars 11, 11, ..., a clamping mechanism 13 and the like. The tie bars 11, 11,... Connect the fixed platen 5 and the clamping housing 10, and the movable platen 6 and the intermediate platen 8 are inserted into the tie bars 11, 11,. The mold clamping mechanism 13 is provided between the mold clamping housing 10 and the movable platen 6 and, in the present embodiment, comprises a toggle mechanism 16 provided with a crosshead 15. The cross head 15 is driven by the mold opening / closing motor 18 and the ball screw mechanism 19, and when the cross head 15 is driven, the toggle mechanism 16 is extended and the movable platen 6 is slid back and forth. That is, the mold is opened and closed.

  The fixed platen 5 is provided with an injection molding die 21. The injection molding die 21 has a plurality of recesses 21a, 21b,... Formed in the parting line. These are bottomed hollow bodies of a resin used for blow molding, that is, recesses 21a, 21b,... For forming a parison by injection molding. Although only three concave portions 21a, 21b,... Are shown in FIG. 1, a large number of concave portions are actually provided. For example, a total of 64 recesses are formed, eight in the longitudinal direction and eight in the lateral direction. In this case, 64 parisons will be formed at the same time. An injection device 3 is provided on the back of the fixed platen 5, and an injection nozzle 3 a of the injection device 3 is in contact with a not-shown sprue of the injection molding die 21.

  The movable platen 6 is provided with a plurality of pairs of blow molding dies 23A, 23a, 23B, 23b,. The pair of blow molding molds 23A, 23a is composed of two split molds 23A, 23a, and slides on the movable plate 6 so as to be separated from or integrated with each other. A recess is formed in the pair of molds 23A and 23a, and when the pair of molds 23A and 23a are slid and integrated, an outer peripheral surface of the hollow molded article is formed from these recesses. A cavity is to be configured. The number of pairs of blow molding dies 23A, 23a, 23B, 23b,... Is equal to the number of recesses 21a, 21b,. Therefore, it is possible to blow-mold hollow molded articles as many as the number of parisons injection-molded at one time in the injection mold 21 at one time.

  In the present embodiment, the intermediate board 8 rotates in reverse. To be precise, the intermediate plate 8 is provided with an outer frame portion 25 sliding along the tie bars 11, 11, ..., and is provided inside the frame portion 25 and rotatably supported with respect to the frame portion 25. And the main body 26. The main body portion 26 is reversely rotated as shown by the arrow in FIG. Cores 30, 30,... Are provided on both sides of the body portion 26 of such an intermediate board 8. As shown in FIG. These cores 30, 30, ... are the cores 30, 30, ... of the surface facing the fixed platen 5 when the mold apparatus 2 is clamped, and the recesses 21a, 21b, ... of the injection molding die 21. And a cavity for parison molding is configured. Further, the cores 30, 30, ... of the surface facing the movable plate 6 are inserted between the respective sets of blow molding dies 23A, 23a, 23B, 23b, ... in a state where the parison is provided. It has become so. The cores 30, 30,... Are provided with jets of air at their tips, so that high pressure air from the high pressure air supply device is jetted from the tips.

  The injection blow molding machine 1 according to the present embodiment is provided with two drive mechanisms for driving the intermediate plate 8. The first drive mechanism is an intermediate disc opening / closing mechanism 14 for opening and closing the intermediate disc 8 with respect to the movable disc 6, and the second drive mechanism reversely rotates the intermediate disc 8, that is, the main body 26 It is a rotation mechanism that rotates in reverse.

  The intermediate board opening and closing mechanism 14 is provided on the movable board 6 and the intermediate board 8 and is composed of a ball screw mechanism 32 and an intermediate board opening and closing servomotor 33 for rotating the same. Specifically, the ball nut 35 of the ball screw mechanism 32 is fixed to the frame 25 of the intermediate disc 8 and is screwed to the ball screw 36. A servomotor 33 for opening and closing the intermediate disc is provided on the movable disc 6 so as to rotate the ball screw 36. The servomotor 33 for opening and closing the intermediate board is provided with an encoder, and can rotate the ball screw 36 with high accuracy by feedback control so that the intermediate board 8 can be opened and closed with respect to the movable board 6 at an accurate position.

  The rotation mechanism for rotating the intermediate disc 8 in reverse is constituted by a servo motor 38 for intermediate disc rotation. The intermediate disc rotating servomotor 38 is provided on the frame 25 of the intermediate disc 8 so as to rotate the main body 26 directly. The intermediate disc rotating servomotor 38 is also provided with an encoder, and the rotational position can be controlled by feedback control to invert the intermediate disc 8, that is, the main body 26.

  Since the two drive mechanisms of these rotary disks 8 are composed of servomotors 33 and 38, the mold open / close position and rotational position can be accurately controlled by feedback control, but since there is no play, when a predetermined external force acts It is easy to deteriorate. In the injection blow molding machine 1 according to the present embodiment, a predetermined operation method is implemented to prevent deterioration of these drive mechanisms. Hereinafter, the operation method will be described while describing a method of forming a hollow molded article by the injection blow molding machine 1.

  As shown in (A) of FIG. 2, the description will be given from the state where the mold apparatus 2 is opened. In this state, the intermediate board rotating servomotor 33 controls the rotational position so that the intermediate board 8, that is, the main body 26 is accurately in the vertical state. From this state, the mold assembly 2 is clamped. As shown in the flow chart of FIG. 3A, first, the intermediate disc opening / closing servomotor 33 is driven to close the intermediate disc 8 with respect to the movable disc 6. Next, the toggle mechanism 16 is driven by the mold opening / closing motor 18 to drive the movable platen 6 in the mold closing direction. Then, the movable platen 6 and the intermediate platen 8 are driven in the direction of the fixed platen 5. Immediately before the intermediate disc 8 and the fixed disc 5 are closed, that is, immediately before the mold 21 is touched, the control of the intermediate disc opening and closing servomotor 33 and the intermediate disc rotating servomotor 38 is stopped. That is, the servo free state is set. Subsequently, the toggle mechanism 16 is driven by the mold open / close motor 18 to clamp the mold. The servomotor 33 for opening and closing the intermediate disc and the servomotor 38 for rotating the intermediate disc are servo-free, so no force is exerted at the time of mold clamping. As a result, no load is applied to the intermediate disc opening / closing servomotor 33, the intermediate disc rotation servomotor 38, and the ball screw mechanism 32, and these deteriorations are prevented. The clamped condition is shown in FIG. A cavity is formed by the recess 21 a of the injection mold 21 and the core 30 of the intermediate plate 8. When resin is injected from the injection device 3, a parison 40 is formed as shown in FIG. 2 (c).

  As shown in FIG. 2D, the mold apparatus 2 is opened to leave the parison 40 on the core 30, and then the rotary table 8, ie, the main body, as shown in FIG. 2E. The unit 26 is reversely rotated. These procedures will be described with reference to the flow chart of FIG. First, the toggle mechanism 16 is driven to open the movable plate 6 and the intermediate plate 8 with respect to the fixed plate 5. The intermediate plate 8 is opened from the movable plate 6 by driving the intermediate plate opening / closing servomotor 33. The driving of the intermediate plate opening / closing servomotor 33 may be started as soon as the fixed plate 5 and the movable plate 6 are separated. When the mold assembly 2 is completely opened, the intermediate disc rotating servomotor 38 is driven to reversely rotate the intermediate disc 8, ie, the main body 26. The servomotor 33 for opening and closing the intermediate board and the servomotor 38 for rotating the intermediate board are completed in a state in which the control is maintained.

  At this time, as shown in FIG. 2 (E), the parison 40 faces the blow molding dies 23A and 23a. The mold assembly 2 is clamped in the order described above. As shown in (f) of FIG. 2, the pair of blow molding dies 23A and 23a are slid and integrated immediately before the mold clamping. Then, the parison 40 is sandwiched between the pair of blow molding dies 23A and 23a. When the high-pressure air supply device is driven to blow high-pressure air from the core 30, a hollow molded article 41 is formed as shown in FIG. At this time, resin is simultaneously injected into the injection mold 21 to mold the parison 40. The mold apparatus 2 is opened in the order described above, and the pair of blow molding dies 23A and 23a are opened. Then, a hollow molded article 41 is obtained as shown in FIG. 2 (g), and the mold is opened in a state where the parison 40 is left on the intermediate plate 8. The same procedure is followed.

  The injection blow molding machine 1 according to the present embodiment and the operation method thereof can be variously modified. For example, in the injection blow molding machine 1, the main body portion 26 of the intermediate board 8 is described as being directly rotated by the intermediate board rotating servomotor 38, but may be rotated via a predetermined reduction gear. Further, although the intermediate board opening and closing mechanism 14 is described as being provided on the movable board 6 and the intermediate board 8, it may be provided on the fixed board 5 and the intermediate board 8. In this case, the intermediate board opening / closing servomotor 33 for driving the ball screw mechanism 32 is provided on the fixed board 5. Further, the direction of the reverse, that is, the rotation of the intermediate disc 8 can be deformed. In the present embodiment, the main body portion 26 of the intermediate board 8 is configured to rotate around a horizontal rotation axis, but may be configured to rotate around a vertical rotation axis. In the operation method according to the present embodiment, the servo motor 33 for opening / closing the intermediate disc and the servo motor 38 for rotating the intermediate disc at the time of mold clamping are servo-free just before the intermediate disc 8 and the fixed disc 5 are closed. It was explained to carry out. However, it may not be immediately before. Generally, a guide pin and a guide hole are provided in the mold so that the mold does not shift when the mold is closed. Although not described in detail, the injection molding machine mold 21 is also provided with a guide pin and a guide hole. When the guide pin is inserted into the guide hole by mold closing, the servomotor 33 for opening and closing the intermediate disc and the servomotor 38 for rotating the intermediate disc may be servo-free.

DESCRIPTION OF SYMBOLS 1 injection blow molding machine 2 mold machine apparatus 3 injection apparatus 5 fixed board 6 movable board 8 middle board 10 mold clamping housing 11 tie bar 13 mold clamping mechanism 14 middle board opening and closing mechanism 21 injection molding mold 21a recessed part 23A, 23a for blow molding Mold 25 Frame body part 26 Body part 30 Core 32 Ball screw mechanism 33 Servomotor for opening and closing the intermediate disc 35 Ball nut 36 Ball screw
38 Servomotor for intermediate plate rotation 40 Parison 41 Hollow molded product

Claims (2)

The mold apparatus comprises a fixed board, a movable board which is opened and closed by a mold clamping mechanism, and an intermediate board provided between the fixed board and the movable board, and the fixed board is provided with a mold for injection molding. A blow molding die is provided on the movable plate respectively, the mold unit is clamped, and a resin is injected from the injection device to form a parison in the injection mold, and when the mold is opened, the parison is It is left on the intermediate plate, and the intermediate plate is reversely rotated to face the parison of the intermediate plate to the movable plate, the mold unit is clamped, and blow molding is performed using the blow molding die. A method of operating an injection blow molding machine wherein hollow molded articles are to be molded from
The intermediate disc is provided with an intermediate disc rotating servomotor provided with an encoder for detecting a rotational angle, and is thereby rotated.
The method for operating an injection blow molding machine according to claim 1, wherein the mold clamping of the mold assembly is performed by stopping the control of the rotation angle by the servomotor for rotating the intermediate disc before the mold touches. In the method of operating an injection blow molding machine according to claim 1, the intermediate board is provided with an intermediate board opening / closing mechanism consisting of a predetermined ball screw mechanism and an intermediate disc opening / closing servomotor on the movable board or the fixed board. By this, the mold is opened and closed with respect to the movable plate or the fixed plate,
The method of operating an injection blow molding machine according to claim 1, wherein the mold clamping of the mold assembly is performed by stopping control by the servomotor for opening and closing the intermediate disc before the mold touches.

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