Rotary transport device, control method, and program

Abstract

The rotary conveying device is provided with: a conveying body that rotates and conveys a workpiece between a plurality of stations by moving in a rotation direction; a positioning part which is clamped with the conveying body at a stop position corresponding to the station and limits the conveying body in the horizontal direction; a motor that drives the conveyance body in the rotational direction; a drive mechanism that transmits the power of the motor to the conveyance body; and a control unit that controls the positioning unit and the motor. The control unit detects a first stop position of the transport body stopped by the control of the motor and a second stop position of the transport body after the positioning unit engages with the transport body, and corrects the next movement amount of the transport body on the basis of the difference between the second stop position and the first stop position.

Description

Technical Field

[0001] The present invention relates to a rotary conveying device, a control method, and a program. Background Art

[0002] Conventionally, a processing device is known that conveys a workpiece between a plurality of processes by a rotational movement of a transfer plate and processes the workpiece. As an example of such a processing device, an injection molding device that injects a preform made of resin, a blow molding device that blow-molds a container from a preform made of resin, etc. can be cited.

[0003] In such a processing device, the transfer plate that conveys the workpiece is respectively positioned at a given position in each process and is restricted from moving during processing. For example, in Patent Document 1, a blow molding device is disclosed in which a locking pin is inserted into a rotating disk at a given stop position to restrict the movement of the rotating disk in the rotational direction. Prior Art Documents Patent Documents

[0004] Patent Document 1: Japanese Patent No. 3200181 Gazette Summary of the Invention Technical Problem to be Solved by the Invention

[0005] In a state where the transfer plate stops at a given position, if there is a positional deviation between the positioning pin and the receiving hole formed in the transfer plate, the positioning pin and the transfer plate interfere with each other, and wear of the receiving hole may occur. If the receiving hole is worn, it becomes difficult to position the transfer plate at an accurate stop position, and thus replacement or repair of the transfer plate is required.

[0006] In addition, the position adjustment of the positioning pin and the receiving hole of the transfer plate is affected by, for example, the weight of a mold, a workpiece, etc. conveyed by the transfer plate, the conveying speed of the transfer plate, etc. For example, in the case where an operator performs the position adjustment of the positioning pin and the receiving hole of the transfer plate, the operator needs to perform the above-described position adjustment when switching the product to be processed or whenever the processing condition setting is changed, and this operation is very complicated. Also, in the case where the position adjustment is performed by an operator, it may not be possible to sufficiently ensure the positioning accuracy between the positioning pin and the transfer plate.

[0007] Therefore, the present invention has been completed in view of such problems, and an object thereof is to provide a rotary conveying device that can accurately and easily perform the position adjustment between a workpiece conveying body and a positioning unit. Technical Solution for Solving the Technical Problem

[0008] One embodiment of the rotary transfer device of the present invention includes: a transfer body that rotates and transfers workpieces between multiple workstations by moving in the rotational direction; a positioning portion that engages with the transfer body at a stop position corresponding to the workstation and restricts the transfer body in the horizontal direction; an electric motor that drives the transfer body in the rotational direction; a drive mechanism that transmits the power of the electric motor to the transfer body; and a control portion that controls the positioning portion and the electric motor. The control portion respectively detects a first stop position of the transfer body stopped by controlling the electric motor and a second stop position of the transfer body after the positioning portion engages with the transfer body, and corrects the next movement amount of the transfer body based on the difference between the second stop position and the first stop position. Advantages of the Invention

[0009] According to one embodiment of the present invention, a rotary transfer device capable of accurately and easily adjusting the position of a workpiece transfer body and a positioning unit can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a diagram showing a structural example of the blow molding device of the present embodiment. Figure 2 It is a diagram showing a structural example of the rotary transfer device. Figure 3 It is a diagram showing a structural example of the control portion of the blow molding device. Figure 4 It is a flowchart showing the steps of a method for manufacturing a container. In Figure 5 Figure 5 (a) of Figure 5 is a diagram showing the positional relationship between the second gear and the first gear when the transfer plate moves, Figure 5 and (b) of is a diagram showing the state of the positioning pin in Figure 6 (a) of Figure 6 In Figure 6 (a) of Figure 6 is a diagram showing the positional relationship between the second gear and the first gear when the control portion instructs the electric motor to stop, and (b) of Figure 7 is a diagram showing the state of the positioning pin in Figure 7 (a) of Figure 6 is a subsequent diagram of Figure 7 (a) of Figure 7 and (b) of In Figure 8 Figure 8 (a) of Figure 7 is a subsequent diagram of Figure 8 (a) of Figure 8The figure of the state of the positioning pin in (a). In Figure 9 it Figure 9 (a) of Figure 8 is the subsequent figure of (a) of Figure 9 (b) of Figure 9 is the figure of the state of the positioning pin in (a) of Figure 10 is the figure showing the case where the transfer plate moves in the reverse direction when it interferes with the positioning pin. Figure 11 is the figure showing an example of judgment of the moving direction of the transfer plate based on the abutting action. Figure 12 is the figure showing an example of judgment of the moving direction of the transfer plate based on the abutting action. Figure 13 is the figure showing an example of the operation of the correction process. Figure 14 is the flowchart showing an example of control of the conveying operation of the transfer plate. Detailed implementation mode

[0011] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the embodiment, for the sake of easy understanding of the description, structures and elements other than the main part of the present invention are simplified or omitted for description. In addition, in the drawings, the same reference numerals are assigned to the same elements. It should be noted that the shapes, sizes, etc. of the respective elements shown in the drawings are schematically represented and do not represent actual shapes, sizes, etc.

[0012] In the present embodiment, as an example of a processing device (molding device) equipped with a rotary conveying device, a structural example of a blow molding device that pre-molds a resin by injection molding and blow-molds the pre-molded parison to manufacture a container will be described. The blow molding device of the present embodiment adopts a hot parison method (also called a one-stage method) that does not cool the pre-molded parison to room temperature and uses the retained heat (internal heat) during injection molding to blow-mold the container. It should be noted that, as described later, as long as the rotary conveying device is a structure that holds the processed product (molded product) on the transfer plate and intermittently rotates and conveys it between processes (between molding parts), it can also be applied to an injection molding device.

[0013] Figure 1 is the figure showing a structural example of the blow molding device of the present embodiment. Figure 2 is the figure showing a structural example of the rotary conveying device included in the blow molding device.

[0014] The blow molding device 1 includes a machine base 2, an upper base plate 4, an injection molding section 10, a temperature adjustment section 12, a blow molding section 14, a take-out section 16, and a control section 22 that controls each section of the blow molding device 1. The upper base plate 3 is supported by a plurality of rod-shaped members (not shown) erected on the machine base 2 and fixed above the machine base 2.

[0015] In the blow molding device 1, the injection molding section 10, the temperature adjustment section 12, the blow molding section 14, and the take-out section 16 are arranged in the space between the machine base 2 and the upper base plate 4. The injection molding section 10, the temperature adjustment section 12, the blow molding section 14, and the take-out section 16 are arranged at positions that rotate a given angle (for example, 90 degrees) each time around the rotation center O in the vertical direction of the paper surface of Figure 1 this.

[0016] The injection molding section 10 has an injection cavity mold and an injection core mold (not shown), and an injection device 11 that supplies a resin material as a preform blank. The injection molding section 10 closes these molds with a neck mold described later to form a mold space in the shape of a preform blank, and injects the resin material into this mold space from the injection device 11, thereby manufacturing a bottomed cylindrical preform blank. It should be noted that the preform blank is an example of a workpiece.

[0017] The temperature adjustment section 12 has a mold unit (temperature control tank, temperature control rod) for temperature adjustment (not shown). The temperature adjustment section 12 equalizes the temperature of the preform blank manufactured by the injection molding section 10 and removes temperature deviation, and adjusts the temperature of the preform blank to a blow molding temperature suitable for final blow molding (for example, about 90°C to 105°C).

[0018] The blow molding section 14 includes a blow molding mold, an introduction member for blow molding air, and a stretching rod (all not shown). The blow molding section 14 performs biaxial stretch blow molding by axially stretching the preform blank having the heat retained during injection molding and arranged in the blow molding mold by using the stretching rod, and introducing high-pressure air (blow molding air) into the inside of the preform blank, thereby manufacturing a container.

[0019] The take-out section 16 opens the neck mold 18 described later by a take-out cam not shown, and takes out the container manufactured by the blow molding section 14 from the blow molding device 1. The container taken out by the take-out section 16 is packed in a box or conveyed to a filling line.

[0020] In addition, at the position of the injection molding section 10 of the upper base plate 4, the upper clamping plate and the injection core mold (both not shown) of the injection molding section 10 are respectively arranged on the upper surface side. At the position of the temperature adjustment section 12 of the upper base plate 4, for example, a temperature adjusting rod and a lifting mechanism of the temperature adjusting rod (both not shown) are arranged on the upper surface side. At the position of the blow molding section 14 of the upper base plate 4, a stretching rod, an introducing member for blow molding air, and their lifting mechanisms (both not shown) are respectively arranged on the upper surface side. In addition, at the position of the take-out section 16 of the upper base plate 4, a take-out cam (not shown) is arranged.

[0021] In addition, the upper base plate 4 supports a transfer plate 6 that rotates intermittently and a motor 20 that drives the transfer plate 6. The transfer plate 6 is an example of a conveying body. It should be noted that although not shown in the figure, the blow molding device 1 further includes a lifting mechanism (a vertical mold opening and closing mechanism) for lifting the transfer plate 6 between the machine table 2 and the upper base plate 4 or between the transfer plate 6 and the machine table 2 to perform the operations related to mold closing and mold opening (demolding).

[0022] The overall shape of the transfer plate 6 is generally fan-shaped or a single disk shape, and it is arranged on the lower surface of the upper base plate 4 in a rotatable manner. In addition, when the transfer plate 6 is in a generally fan-shaped case, a plurality of them are arranged (for example, 4 quarter circles are arranged when there are 4 molding stations), and when the transfer plate 6 is in a disk shape, one is arranged. On the lower surface of each transfer plate 6, a support plate 8 (a pair of split plates) is arranged, and the support plate 8 supports a plurality of (for example, 8) neck molds 18 as split molds in an openable and closable manner. The plurality of or single transfer plates 6 are guided by a guiding member 46 described later on the upper base plate 4 and intermittently move at a given angle (for example, 90 degrees) in the rotational direction (forward rotation direction) with the rotation center O as the rotation axis. The preform (or container) held by the neck mold 18 on the transfer plate 6 is conveyed in the order of the injection molding section 10, the temperature adjustment section 12, the blow molding section 14, and the take-out section 16 through the movement of the transfer plate 6.

[0023] The motor 20 is, for example, a pulse motor or a servo motor, and its rotation amount and torque are controlled by a control unit 22 via a conveying drive unit 65 described later. As Figure 2 shown, the rotation axis A of the motor 20 is arranged at a position eccentric with respect to the rotation center O of the transfer plate 6 and is connected to a speed reducer 24 that decelerates the output of the motor 20 at a given reduction ratio. The speed reducer 24 is fixed to the upper base plate 4 by bolts via a speed reducer fixing plate 28. Thus, the motor 20 and the speed reducer 24 are mounted on the upper surface of the upper base plate 4.

[0024] In addition, a gear fixing metal member 32 is fixed to the output shaft 26 of the speed reducer 24 via a first key 34. A second gear 30 is fixed to the gear fixing metal member 32 via a second key 36. The gear fixing metal member 32 is supported via a first bearing 38 so as to be rotatable relative to the speed reducer fixing plate 28. Thus, the second gear 30 rotates as the output shaft 26 rotates.

[0025] On the other hand, a first gear 40 is provided on the transfer plate 6. The first gear 40 has internal teeth that mesh with the second gear 30. The first gear 40 is fixed to an intermediate member 43 connected to the transfer plate 6 via bolts 44 and is supported via a second bearing 42 so as to be rotatable relative to the upper base plate 4. In addition, a guide member 46 that supports the lower surface of the peripheral edge portion of the transfer plate 6 is provided on the outer edge portion of the upper base plate 4. It should be noted that the output of the speed reducer 24 is further decelerated by the first gear 40 and the second gear 30. The first gear 40 and the second gear 30 are an example of a drive mechanism.

[0026] In addition, a cylinder 52 that moves a positioning pin 50 forward and backward in the vertical direction (the plumb direction) is provided on the upper base plate 4. On the other hand, a receiving hole 54 for receiving the positioning pin 50 is formed in the transfer plate 6. When the holding plate 8 that supports the neck mold 18 is in the stop position facing each station, the positioning pin 50 is inserted into the receiving hole 54 of the transfer plate 6. By the engagement of the positioning pin 50 and the receiving hole 54, the transfer plate 6 is positioned and its movement in the rotational direction is restricted.

[0027] It should be noted that the positioning pin 50 and the cylinder 52 can be respectively arranged at the stop positions of each station, or can be arranged at the stop positions of any one or more of the four stations.

[0028] Figure 3 It is a diagram showing a structural example of the control unit 22 of the blow molding apparatus 1. The control unit 22 includes a CPU (Central Processing Unit), a RAM (Random Access Memory) 62, a storage unit 63, an operation unit 64, a conveyance drive unit 65, a positioning drive unit 66, an injection molding drive unit 67, a temperature adjustment drive unit 68, a blow molding drive unit 69, and a take-out drive unit 70. Each element of the control unit 22 is interconnected via a bus 60.

[0029] The CPU 61 is a processor that executes programs stored in the storage unit 63 and uniformly controls each part of the blow molding apparatus 1. The RAM 62 is a memory that functions as a main memory, a working area, etc. of the CPU 61. The storage unit 63 includes, for example, a hard disk, a solid-state drive, etc., which store programs and various data.

[0030] The operation unit 64 is a module that receives inputs of the operating conditions of various actuators in the blow molding apparatus 1 and the processing conditions (molding conditions) of the preform / container (e.g., change in the conveying speed of the transfer plate 6, etc.) from the operator. The operation unit 64 includes, for example, an operation panel having a plurality of input buttons, a touch panel device having a screen display function in which a light-transmissive touch panel is laminated on a liquid crystal screen, and the like.

[0031] The conveyance drive unit 65 is a driver and interface for controlling the rotation amount and torque of the motor 20. The conveyance drive unit 65 detects the rotation amount of the motor 20 from an encoder (not shown) attached to the rotation shaft A of the motor 20. The positioning drive unit 66 is a driver and interface for controlling the cylinder 52 that moves the positioning pin 50 forward and backward.

[0032] The injection molding drive unit 67 is a driver and interface for performing injection control of the injection device 11 in the injection molding unit 10, mold opening / closing control of the injection cavity mold and the injection core mold, and the like. The temperature adjustment drive unit 68 is a driver and interface for performing temperature control of the mold unit in the temperature adjustment unit 12, mold opening / closing control of the mold unit, and the like.

[0033] The blow molding drive unit 69 is a driver and interface for performing mold opening / closing control of the blow molding mold in the blow molding unit 14, longitudinal axis stretching control based on the stretching rod, flow rate control of the compressed air, and the like. The take-out drive unit 70 is a driver and interface for performing mold opening control of the neck mold 18 in the take-out unit 16, and the like.

[0034] Next, a method for manufacturing a container using the blow molding apparatus 1 according to the present embodiment will be briefly described. Figure 4 It is a flowchart showing the steps of the method for manufacturing a container.

[0035] (Step S101: Injection molding process) In step S1, in the injection molding unit 10, resin is injected from the injection device 11 into the mold space having a preform shape formed by the injection cavity mold, the injection core mold, and the neck mold 18 to manufacture a preform.

[0036] Then, the injection cavity mold and the injection core mold are opened, and the preform having the heat retained during injection molding is demolded from the mold. Then, the transfer plate 6 moves by an amount of rotating a given angle, and the preform held by the neck mold 18 is conveyed to the temperature adjustment unit 12.

[0037] (Step S102: Temperature adjustment process) Next, in the temperature adjustment unit 12, the preform is housed in a temperature-controlled tank adjusted to a given temperature, and a temperature-controlled rod adjusted to a given temperature is inserted into the preform. Thereby, temperature adjustment for bringing the temperature of the preform close to the temperature suitable for final blow molding and reduction of temperature unevenness generated during injection molding are performed.

[0038] Then, the mold unit of the temperature adjustment unit 12 is opened, and the temperature-adjusted preform is demolded from the mold. Then, the transfer plate 6 moves by an amount of rotating a given angle, and the preform held by the neck mold 18 is conveyed to the blow molding unit 14.

[0039] (Step S103: Blow molding process) Next, in the blow molding unit 14, blow molding of the container is performed. First, when the preform is housed in the blow molding mold of the blow molding unit 14, the blow molding mold is closed to form a mold space corresponding to the shape of the container. Next, the blow air introduction member and the stretching rod are inserted into the preform, and the preform is axially stretched by the lowering of the stretching rod. After that, blow air is introduced into the preform from the blow air introduction member. Thereby, the preform bulges in a manner that closely adheres to the blow molding mold and is blow molded into a container.

[0040] (Step S104: Container removal process) When the blow molding is completed, the blow molding mold is opened. Next, the transfer plate 6 moves by an amount of rotating a given angle, and the container is conveyed to the removal unit 16. In the removal unit 16, the neck of the container is released from the neck mold 18, and the container is removed to the outside of the blow molding apparatus 1.

[0041] Thus, one cycle in the manufacturing method of the container ends. After that, the transfer plate moves by an amount of rotating a given angle, and the above-described steps from S101 to S104 are repeated. It should be noted that when the blow molding apparatus 1 is operating, four sets of containers with a time difference of one process each are manufactured in parallel.

[0042] In addition, in the structure of the blow molding apparatus 1, the times of the injection molding process, the temperature adjustment process, the blow molding process, and the container removal process are respectively of the same length. Similarly, the conveyance times between the respective processes are also respectively of the same length.

[0043] Next, the conveying operation of the transfer plate 6 in this embodiment will be described. In the blow molding apparatus 1 of this embodiment, as described above, through the control of the control unit 22, the transfer plate 6 intermittently moves in the rotational direction, and the holding plates 8 stop at the stop positions facing the respective stations. It should be noted that, in the following description, the rotational direction in which the transfer plate 6 moves in the order of the injection molding section 10, the temperature adjustment section 12, the blow molding section 14, and the take-out section 16 is also referred to as the forward rotation direction, and the rotational direction opposite thereto is also referred to as the reverse rotation direction. It should be noted that the forward rotation direction is an example of the conveying direction.

[0044] When the transfer plate 6 is at the stop position, by the drive of the air cylinder 52, the positioning pin 50 descends and is inserted into the receiving hole 54 of the transfer plate 6. Then, the positioning pin 50 engages with the receiving hole 54, and the transfer plate 6 is positioned at the stop position and the movement in the rotational direction is restricted. After that, when the positioning pin 50 is raised by the drive of the air cylinder 52 and retracts from the transfer plate 6, the engagement between the receiving hole 54 and the positioning pin 50 is released, and the transfer plate 6 can move in the forward rotation direction again. The operation of the air cylinder 52 described above is performed whenever the transfer plate 6 moves through the control of the control unit 22.

[0045] However, when the positioning pin 50 is inserted into the receiving hole 54 of the transfer plate 6, if the transfer plate 6 is displaced from the stop position, the positioning pin 50 will interfere with the transfer plate 6 (the outer edge portion of the receiving hole 54). If the positioning pin 50 interferes with the transfer plate 6 every time the transfer plate 6 stops, the receiving hole 54 will be worn and its shape will become larger, making it difficult to position the transfer plate 6 at the accurate stop position. In addition, the wear powder generated by the wear of the receiving hole 54 may also be mixed into the processed product.

[0046] Therefore, the control unit 22 of this embodiment performs the position adjustment operation of the receiving hole 54 of the transfer plate 6 and the positioning pin 50 as follows.

[0047] In the position adjustment operation, first, the control unit 22 accurately obtains the position offset amount between the receiving hole 54 and the positioning pin 50 by setting a state where there is no backlash between the second gear 30 on the motor 20 side and the first gear 40 on the transfer plate 6 side in the forward rotation direction side. The state where there is no backlash in the forward rotation direction side is a state where the second gear 30 presses the first gear 40 or the first gear 40 presses the second gear 30. Then, the control unit 22 corrects the movement amount of the transfer plate 6 based on the obtained position offset amount so that the position offset between the receiving hole 54 and the positioning pin 50 is within the dimensional tolerance. As a result, when the transfer plate 6 comes to the stop position after the next time, the position offset between the receiving hole 54 and the positioning pin 50 becomes smaller, and the positioning pin 50 no longer interferes with the transfer plate 6.

[0048] Hereinafter, with reference to the drawings, the position adjustment operation of the receiving hole 54 and the positioning pin 50 will be described in detail.Figure 5 Fig. (a) shows the positional relationship between the second gear 30 and the first gear 40 when the transfer plate 6 moves. Figure 5 Fig. (b) shows Figure 5 the state of the positioning pin 50 in Fig. (a).

[0049] When the transfer plate 6 moves, as Figure 5 shown in Fig. (b), the positioning pin 50 is in a state of retracting from the transfer plate 6. In addition, as Figure 5 shown in Fig. (a), the second gear 30 on the motor 20 side presses the first gear 40 on the transfer plate 6 side in the forward rotation direction. Thus, the first gear 40 meshes with the second gear 30, and since the power of the motor 20 is transmitted to the transfer plate 6, the transfer plate 6 moves in the forward rotation direction.

[0050] Figure 6 Fig. (a) shows the positional relationship between the second gear 30 and the first gear 40 when the control unit 22 instructs the motor 20 to stop. Figure 7 Fig. (a), Figure 8 Fig. (a), Figure 9 Fig. (a) is the subsequent figure thereof. In addition, Figure 6 Fig. (b), Figure 7 Fig. (b), Figure 8 Fig. (b), Figure 9 Fig. (b) respectively show Figure 6 Fig. (a), Figure 7 Fig. (a), Figure 8 Fig. (a), Figure 9 the state of the positioning pin in Fig. (a).

[0051] At the stop position of the transfer plate 6, as Figure 6 shown in Fig. (b), the receiving hole 54 of the transfer plate 6 is located below the positioning pin 50. When the control unit 22 gives an instruction to stop the motor 20 at the stop command position P0, as Figure 6 shown in Fig. (a), the second gear 30 fixed to the rotating shaft A of the motor 20 stops. On the other hand, the first gear 40 on the transfer plate 6 side rotates in the forward rotation direction due to the inertial force acting on the transfer plate 6.

[0052] When the first gear 40 on the transfer plate 6 side rotates in the forward rotation direction due to inertial force, as Figure 7 shown in Fig. (a), the first gear 40 contacts the stopped second gear 30. Then, although the second gear 30 becomes an obstacle and the first gear 40 stops soon after, the second gear 30 receiving the first gear 40 rotates in the forward rotation direction from the stop command position P0. It should be noted that in Figure 7 the state of Fig. (a), due to the inertial movement of the transfer plate 6, as Figure 7As shown in (b), the position of the receiving hole 54 of the transfer plate 6 is shifted in the forward rotation direction compared to Figure 6 that in (b).

[0053] Figure 8 (a) and (b) of show the state when the positioning pin 50 is lowered. In Figure 8 (a) of, the stop command position P0 of the motor and the stop position P1 after inertial movement are respectively shown. It should be noted that Figure 8 in (a) of, the first gear 40 presses the second gear 30, which is equivalent to a state without backlash on the forward rotation side. Therefore, the control unit 22 can detect the stop position P1 after inertial movement from the encoder of the motor 20. The stop position P1 after inertial movement is an example of the first stop position.

[0054] After the inertial movement of the transfer plate 6 stops, the control unit 22 gives an instruction to lower the positioning pin 50. Then, as Figure 8 shown in (b) of, by driving the cylinder 52, the positioning pin 50 descends from the state in Figure 7 (b) of.

[0055] Figure 9 (a) and (b) of show the state where the positioning pin 50 is inserted into the receiving hole 54 of the transfer plate 6. It should be noted that in Figure 9 (a) and (b) of, the transfer plate 6 is located at a position where it interferes with the positioning pin 50, and the transfer plate 6 moves in the forward rotation direction.

[0056] When the positioning pin 50 is inserted into the receiving hole 54 in a state where the transfer plate 6 interferes with the positioning pin 50, as Figure 9 shown in (b) of, when inserting, the transfer plate 6 is pressed by the positioning pin 50, and the transfer plate 6 further moves in the forward rotation direction. Then, the first gear 40 on the transfer plate 6 side presses the second gear 30 on the motor 20 side in the forward rotation direction, and the second gear 30 rotates from the stop position P1 after inertial movement to the final stop position P2. It should be noted that Figure 9 in (a) of, the first gear 40 presses the second gear 30, which is equivalent to a state without backlash on the forward rotation side. Therefore, the control unit 22 can detect the final stop position P2 from the encoder of the motor 20. The final stop position P2 is an example of the second stop position.

[0057] In order to avoid interference between the transfer plate 6 and the positioning pin 50, it is only necessary to make the stop position P1 after the inertial movement of the second gear 30 coincide with the final stop position P2. Therefore, the control unit 22 calculates a correction value obtained by subtracting the stop position P1 after the inertial movement from the final stop position P2 based on the movement amount of the transfer plate 6, and corrects the movement amount applied in the next movement of the transfer plate 6 (adding the value based on the correction value (P2 - P1) to the command value of the next stop command position P0). As a result, in the next movement of the transfer plate 6, the stop position P1 after the inertial movement of the second gear 30 coincides with the final stop position P2, and the receiving hole 54 is located at the position of the positioning pin 50. Therefore, the positioning pin 50 no longer interferes with the transfer plate 6.

[0058] Here, in the above example, the case where the transfer plate 6 moves in the forward rotation direction when the transfer plate 6 interferes with the positioning pin 50 has been described. However, as Figure 10 shown in (a) of, there is also a case where the transfer plate 6 moves in the reverse rotation direction when the transfer plate 6 interferes with the positioning pin 50.

[0059] Even when the transfer plate 6 moves in the reverse rotation direction, before the positioning pin 50 descends, due to the inertial movement of the transfer plate 6, the first gear 40 also presses the second gear 30 (refer to Figure 10 (b) of). However, if the positioning pin 50 descends, the transfer plate 6 moves in the reverse rotation direction. As a result, as Figure 10 shown by the single-dot chain line in (c) of, the first gear 40 separates from the second gear 30. In Figure 10 the state of (c) of, since the difference (movement amount) between the stop position P1 after the inertial movement and the final stop position P2 is absorbed by the backlash on the reverse rotation side (because it converges within the distance / clearance of the backlash on the reverse rotation side), the deviation of the transfer plate 6 cannot be accurately obtained by the encoder of the motor 20.

[0060] As a countermeasure against the above problem, the control unit 22 of the present embodiment performs the following abutting action and determines the direction in which the transfer plate 6 moves due to the insertion of the positioning pin 50.

[0061] After the transfer plate 6 is restricted by being inserted with the positioning pin 50, the control unit 22 rotates the motor 20 in the forward rotation direction at a low torque such that the transfer plate 6 does not move. Then, the control unit 22 stops the rotation of the motor 20 at the moment when the second gear 30 contacts the first gear 40. The control unit 22 determines that the second gear 30 contacts the first gear 40, for example, when the difference between the commanded rotation speed of the motor 20 and the actual rotation speed acquired by the encoder is equal to or greater than a given value (i.e., when the load on the motor 20 increases). In addition, the control unit 22 sets the clearance G (clearance, distance) formed between the two gears on the non-contact side or the maximum allowable value of the clearance G in the state where the first gear 40 abuts against the second gear 30 as a threshold value.

[0062] Figure 11 , Figure 12 FIG. is a diagram showing an example of determining the moving direction of the transfer plate 6 based on the abutting operation. Figure 11 shows the case where the transfer plate 6 moves in the forward rotation direction due to the insertion of the positioning pin 50, Figure 12 shows the case where the transfer plate 6 moves in the reverse rotation direction due to the insertion of the positioning pin 50.

[0063] As Figure 11 shown, when the transfer plate 6 moves in the forward rotation direction due to the insertion of the positioning pin 50, the first gear 40 on the transfer plate 6 side presses the second gear 30 in the forward rotation direction. That is, in the example of Figure 11 , as shown in the upper diagram, a clearance G is generated between the second gear 30 and the first gear 40 on the forward rotation side of the second gear 30. Therefore, when the motor 20 is rotated in the forward rotation direction at a low torque, although the load on the motor 20 is small in the interval of the above-mentioned clearance G, as shown in the lower diagram of Figure 11 , if the second gear 30 presses the first gear 40, the load on the motor 20 increases. In addition, through the abutting operation, it can be detected that the second gear 30 has moved in the forward rotation direction by the same distance as the clearance G. Thereby, the control unit 22 can determine that the transfer plate 6 has moved in the forward rotation direction (advancing direction) due to the insertion of the positioning pin 50, and can accurately obtain the offset of the transfer plate 6 through the encoder of the motor 20.

[0064] On the other hand, as Figure 12 shown, when the transfer plate 6 moves in the reverse rotation direction due to the insertion of the positioning pin 50, the first gear 40 on the transfer plate 6 side presses the second gear 30 in the reverse rotation direction. That is, in the example of Figure 12 , as shown in the upper diagram, there is almost no clearance between the second gear 30 and the first gear 40 on the forward rotation side of the second gear 30. Therefore, as Figure 12As shown in the figure on the lower side, when the motor 20 rotates in the forward rotation direction with low torque, the second gear 30 presses the first gear 40, so the load of the motor 20 shows a high value from the beginning. In addition, through the abutting action, it can be detected that the second gear 30 has moved a distance less than the clearance G (for example, 1 / 2 of the clearance G) in the forward rotation direction. Thus, the control unit 22 can judge that due to the insertion of the positioning pin 50, the transfer plate 6 moves in the reverse rotation direction (retreat direction), and the deviation of the transfer plate 6 cannot be accurately obtained through the encoder of the motor 20.

[0065] Therefore, as Figure 11 shown, when the clearance G is detected during the abutting action (when the load of the motor 20 increases from the middle), the control unit 22 judges that due to the insertion of the positioning pin 50, the transfer plate 6 moves in the forward rotation direction. In this case, the control unit 22 calculates a correction value obtained by subtracting the stop position P1 after inertial movement from the final stop position P2 based on the movement amount of the transfer plate 6, and corrects the movement amount applied in the next movement of the transfer plate 6.

[0066] On the other hand, as Figure 12 shown, when the clearance G cannot be detected during the abutting action (when the load of the motor 20 is large from the beginning), the control unit 22 judges that due to the insertion of the positioning pin 50, the conveying plate 6 moves in the reverse rotation direction.

[0067] In this case, regardless of the difference between P2 and P1, the control unit 22 performs a correction process of offsetting the movement amount of the transfer plate 6 by a given amount (for example, a value on the order of the radius of the positioning pin) in the reverse rotation direction. Figure 13 (a) of Figure 13 shows the positional relationship between the positioning pin 50 and the receiving hole 54 before the correction process,

[0068] Figure 14 is a flowchart showing a control example of the conveying operation of the transfer plate 6. The control of the conveying operation including the position adjustment operation is realized by the CPU 61 executing a program loaded from the storage unit 63 to the RAM 62 in the control unit 22. It should be noted that this program is not limited to being installed at the time of device factory shipment, and can also be provided to existing devices through updates, etc.

[0069] In step S201, the control unit 22 gives an instruction to the motor 20 to move the transfer plate 6 in the forward rotation direction by a given amount of movement.

[0070] In step S202, when the transfer plate 6 moves to the stop position, the control unit 22 gives a stop command to the motor 20. The position at this time corresponds to the stop command position P0.

[0071] In step S203, the control unit 22 detects the stop position P1 after inertial movement from the encoder of the motor 20.

[0072] In step S204, after the transfer plate 6 stops, the control unit 22 drives the cylinder 52 to lower the positioning pin 50. Thus, the positioning pin 50 is inserted into the receiving hole 54 of the transfer plate 6.

[0073] In step S205, after the positioning pin 50 is inserted, the control unit 22 detects the final stop position P2 from the encoder of the motor 20.

[0074] In step S206, after the positioning pin 50 is inserted, the control unit 22 performs a counteraction operation of rotating the motor 20 in the forward rotation direction with a low torque such that the transfer plate 6 does not move. Then, the control unit 22 determines the moving direction of the transfer plate 6 accompanying the insertion of the positioning pin 50 based on the load of the motor 20 or the encoder of the motor 20.

[0075] In step S207, the control unit 22 determines whether the moving direction of the transfer plate 6 accompanying the insertion of the positioning pin 50 is the forward rotation direction. If the moving direction is the forward rotation direction (yes), the process proceeds to S208. On the other hand, if the moving direction is the reverse rotation direction (no), the process proceeds to S209.

[0076] In step S208, the control unit 22 calculates a correction value obtained by subtracting the stop position P1 after inertial movement from the final stop position P2 based on the amount of movement of the transfer plate 6, and corrects the amount of movement to be applied in the next movement of the transfer plate 6. After that, the process proceeds to S210.

[0077] In step S209, the control unit 22 performs a correction process of offsetting the amount of movement of the transfer plate 6 in the reverse rotation direction by a given amount. After that, the process proceeds to S210.

[0078] In step S210, the control unit 22 drives the cylinder 52 to raise the positioning pin 50 to retract it from the receiving hole 54 of the transfer plate 6. Thus, the engagement between the receiving hole 54 and the positioning pin 50 is released, and the transfer plate 6 can move in the forward rotation direction again. After that, the process returns to S201, and the control unit 22 repeats the above operations. The above is the end Figure 14 of the description.

[0079] Next, the effects of this embodiment will be described. The blow molding apparatus 1 of this embodiment includes: a transfer plate 6 that rotates and conveys a preform between a plurality of stations by moving in the rotational direction; a positioning pin 50 that engages with the transfer plate 6 at a stop position corresponding to the station and restricts the transfer plate 6 in the horizontal direction; a motor 20 that drives the transfer plate 6 in the rotational direction; a first gear 40 and a second gear 30 that transmit the power of the motor 20 to the transfer plate 6; and a control unit 22 that controls the positioning pin 50 and the motor 20. The control unit 22 respectively detects a first stop position (P1) of the transfer plate 6 stopped by the control of the motor 20 and a second stop position (P2) of the transfer plate 6 after the positioning pin 50 engages with the transfer plate 6, and corrects the next movement amount of the transfer plate 6 based on the difference between the second stop position and the first stop position.

[0080] According to this embodiment, since the control unit 22 automatically corrects the next movement amount of the transfer plate 6 using the detected second stop position and first stop position, it is possible to accurately and easily adjust the position of the receiving hole 54 of the transfer plate 6 and the positioning pin 50 without relying on an operator. As a result, wear of the receiving hole 54 caused by interference between the transfer plate 6 and the positioning pin 50 can be suppressed, the frequency of replacement and repair of the transfer plate 6 is reduced, and the generation of wear powder can also be suppressed.

[0081] In addition, according to this embodiment, since the position adjustment of the receiving hole 54 of the transfer plate 6 and the positioning pin 50 is automatically performed, in the case of switching the product to be processed (formed), changing the setting of the processing conditions (forming conditions), replacing the mold (neck mold 18, holding plate 8, etc.) provided on the transfer plate 6, etc., the position adjustment operation of the receiving hole 54 and the positioning pin 50 performed by the operator is reduced. Therefore, the operation cost of the apparatus can be reduced.

[0082] The present invention is not limited to the above embodiment, and various improvements and design changes can also be made without departing from the gist of the present invention.

[0083] In the position adjustment operation of the above embodiment, an example is described in which the moving speed of the transfer plate is relatively fast and backlash of the gear is generated in the reverse direction when the transfer plate 6 stops. However, when the moving speed of the transfer plate is relatively slow, the inertial force acting on the transfer plate becomes smaller, so the stop command position P0 of the motor and the stop position P1 after inertial movement are almost unchanged. Therefore, when the moving speed of the transfer plate is relatively slow, the control unit can also execute the above position adjustment operation by regarding the stop command position P0 of the motor as the stop position P1 after inertial movement. In this case, the stop command position P0 becomes an example of the first stop position.

[0084] In addition, in the above-described embodiment, although an example in which the rotary conveying device is installed in the blow molding device 1 has been described, the rotary conveying device of the present invention can be installed in all other processing devices. As an example, the rotary conveying device of the present invention can also be installed in an injection molding device (for example, the injection molding device disclosed in Japanese Patent Application Laid-Open No. 03-140219), which includes: an injection molding section that injects resin products such as preform blanks; a post-cooling section that cools the resin product after injection molding by storing it in a cooling mold; and a take-out section that takes out the cooled product. In the above case, the arrangement angle of each station and the rotation amount of the transfer plate are 120 degrees apart.

[0085] In addition, in the above-described embodiment, although an example in which the rotary conveying device is installed in a blow molding device having four stations has been described, the structure of the blow molding device is not limited to the above-described embodiment. For example, the blow molding device may have the following structure: successively including five stations of a first injection molding section, a second injection molding section, a temperature adjustment section, a blow molding section, and a take-out section, and the blow molding device can manufacture multi-layer containers by forming a multi-layer preform blank. In this case, the arrangement angle of each station and the rotation amount of the transfer plate are 72 degrees apart. Further, as a deformation example of the above, the blow molding device may have the following structure: including six stations of a first injection molding section, a first temperature adjustment section, a second injection molding section, a second temperature adjustment section, a blow molding section, and a take-out section. In this case, the arrangement angle of each station and the rotation amount of the transfer plate are 60 degrees apart.

[0086] In addition, as long as the blow molding device and the injection molding device equipped with the rotary conveying device have the following mechanism, the overall structure of the device can also be any structure. The mechanism is to hold the workpiece (such as a preform blank) by using a mold member (such as a neck mold) provided on the transfer plate and convey the workpiece to the downstream side (downstream process or molding station) by the intermittent rotation of the transfer plate. For example, the number of stations of the blow molding device and the injection molding device can be two (for example, an injection molding section and a take-out section), or three (for example, an injection molding section, a blow molding section, and a take-out section).

[0087] In addition, in the above-described embodiment, the control section may also include hardware (such as an ASIC, etc.) that implements the functions of the program.

[0088] In addition, all the contents of the embodiments disclosed this time should be regarded as illustrative rather than restrictive. The scope of the present invention is shown not by the above description but by the scope of the patent claims, and is intended to include meanings equivalent to the scope of the patent claims and all changes within the scope. Description of Reference Numerals

[0089] 1: Blow molding device, 4: Upper base plate, 6: Transfer plate, 10: Injection molding section, 12: Temperature adjustment section, 14: Blow molding section, 16: Take-out section, 20: Motor, 22: Control section, 30: Second gear, 40: First gear, 50: Positioning pin, 52: Cylinder, 54: Receiving hole.

Claims

1. A rotary conveying device, comprising: A conveying body that rotates and conveys workpieces among a plurality of workstations by moving in the rotational direction; A positioning portion that engages with the conveying body at a stop position corresponding to the workstation and restricts the conveying body in the horizontal direction; A motor that drives the conveying body in the rotational direction; A drive mechanism that transmits the power of the motor to the conveying body; and A control portion that controls the positioning portion and the motor, The control portion respectively detects a first stop position of the conveying body stopped by controlling the motor, and a second stop position of the conveying body after the positioning portion engages with the conveying body, and corrects the next movement amount of the conveying body based on the difference between the second stop position and the first stop position.

2. The rotary conveying device according to claim 1, Wherein, The control portion detects the position where the conveying body stops after inertial movement after the rotation of the motor stops as the first stop position.

3. The rotary conveying device according to claim 2, Wherein, The control portion detects the first stop position and the second stop position based on the rotation amount of the motor.

4. The rotary conveying device according to claim 2, Wherein, After detecting the second stop position, the control portion drives the motor in the conveying direction with a torque that does not move the restricted conveying body and detects the clearance of the gear of the drive mechanism, The control portion determines the deviation direction of the conveying body when the positioning portion engages with the conveying body based on the size of the clearance.

5. The rotary conveying device according to claim 4, Wherein, When the deviation direction of the conveying body is in the direction opposite to the conveying direction of the workpiece, the control portion performs a process of offsetting the movement amount of the conveying body in the direction opposite to the conveying direction by a given amount regardless of the difference.

6. A control method, which is a control method of a rotary conveying device, the rotary conveying device comprising: A conveying body that rotates and conveys workpieces among a plurality of workstations by moving in the rotational direction; A positioning portion that engages with the conveying body at a stop position corresponding to the workstation and restricts the conveying body in the horizontal direction; A motor that drives the conveying body in the rotational direction; and A drive mechanism that transmits the power of the motor to the conveying body, The control method of the rotary conveying device includes: A process of detecting a first stop position of the conveying body stopped by controlling the motor; A process of detecting a second stop position of the conveying body after the positioning portion engages with the conveying body; and A process of correcting the next movement amount of the conveying body based on the difference between the second stop position and the first stop position.

7. A program that causes a computer of a rotary conveying device to execute processes, the rotary conveying device comprising: A conveying body that rotates and conveys workpieces among a plurality of workstations by moving in the rotational direction; A positioning portion that engages with the conveying body at a stop position corresponding to the workstation and restricts the conveying body in the horizontal direction; A motor that drives the conveyor in the rotational direction; and a drive mechanism that transmits the power of the motor to the conveyor, The process includes: a process of detecting a first stop position of the conveyor that has stopped by controlling the motor; a process of detecting a second stop position of the conveyor after the positioning portion engages with the conveyor; and a process of correcting a next movement amount of the conveyor based on a difference between the second stop position and the first stop position.

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