Low-noise one-step injection-drawing bottle blowing machine

Abstract

The invention relates to the technical field of bottle blowing machines, in particular to a low-noise one-step injection drawing bottle blowing machine which comprises a rack and a transmission belt. A mounting plate is arranged on the rack, an injection mold and a blow mold are fixedly arranged on the mounting plate, a lifting frame is arranged on the mounting plate in a sliding manner, a turntable assembly is clamped in the middle of the lifting frame in a sliding manner, and at least three groups of mold nozzle assemblies are arranged on the turntable assembly; a lead screw is rotationally arranged in the rack, and the lower end of the lead screw is in threaded connection with the lower end of the lifting frame and is in transmission with a servo motor through a synchronous wheel and a transmission belt. A transmission structure composed of the synchronous wheel and the transmission belt is used for replacing a speed reducer, the lifting frame is driven to slide up and down on the rack under the action of the servo motor and the lead screw, then the working noise of the bottle blowing machine is reduced, and a low-noise environment is provided for workers. In addition, the servo cam rotary table is used for replacing a traditional linear servo speed reducer to drive the rotary table to rotate, and the levelness of the rotary table and the accuracy of the shutdown angle are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of bottle blowing machines, and more specifically, it relates to a low-noise one-step injection stretch blow molding machine. Background Art

[0002] Most beverage bottles on the market are produced by bottle blowing machines. A bottle blowing machine is a machine that extrudes or injects a thermoplastic resin or plastic to obtain a tubular preform. After heating to a softened state, it is placed in a split mold. After the mold closing mechanism drives the mold to close, compressed air is immediately introduced into the preform to blow up the plastic preform and make it adhere tightly to the inner wall of the mold. After cooling and demolding, various hollow products are made.

[0003] In the stage of forming the preform of the existing bottle blowing machine, a hydraulic device is mainly used to lock the injection mold (reference can be made to CN204431711U). Although a large mold locking pressure can be obtained, the hydraulic device is easily affected by voltage. When the voltage is too high or too low, the mold locking pressure will change, resulting in mold shaking or displacement, and problems such as bottle body deformation and uneven wall thickness.

[0004] To solve the problem that the mold locking pressure of the existing bottle blowing machine is prone to instability during the injection molding stage, the applicant previously applied for a bottle blowing machine (publication number CN119369691A). This bottle blowing machine includes a power device composed of a servo motor, a reducer, and a lead screw for driving the lifting frame to slide up and down on the frame, so that the mold nozzle assembly is adapted to the injection mold with a constant mold locking pressure under the drive of the turntable assembly, avoiding problems such as deformation, uneven wall thickness, and unstable bottle mouth size of the preform due to unstable mold locking pressure when the voltage is unstable. However, the inside of the reducer mainly relies on bevel gear transmission, which has the disadvantage of high noise in actual production and seriously affects the working environment. Summary of the Invention

[0005] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide a low-noise one-step injection stretch blow molding machine to solve the technical problem of high working noise of the existing bottle blowing machine.

[0006] The above technical purpose of the present invention is achieved through the following technical solutions:

[0007] A low-noise one-step injection stretch blow molding machine, comprising a frame and a transmission belt; an installation plate is arranged on the frame, and an injection mold for forming a preform and a blow molding mold for blowing the preform into a bottle body are arranged on the installation plate. A lifting frame that slides vertically is slidably arranged on the installation plate. A turntable assembly is slidably clamped in the middle of the lifting frame. At least three sets of nozzle assemblies for adapting to the injection mold to thermoform plastic into a preform and conveying the preform to the blow molding mold are arranged on the turntable assembly; a lead screw for driving the lifting frame to slide up and down is rotatably arranged in the frame, and the lead screw is threadedly connected to the lower end of the lifting frame; a synchronous pulley is arranged at the lower end of the lead screw, and a servo motor is arranged in the frame; one end of the transmission belt is wound around the synchronous pulley, and the other end is wound around the output pulley of the servo motor; the lower end of the lifting frame is located below the installation plate, and the upper end is located above the installation plate.

[0008] Optionally, the lifting frame includes an upper end plate located above the installation plate, a lower end plate located below the installation plate, and four guide columns slidably connected to the installation plate; the guide columns penetrate the installation plate, the upper ends thereof are fixedly connected to the upper end plate, and the lower ends thereof are fixedly connected to the lower end plate; a limit sleeve for preventing the turntable assembly from abutting against the upper end plate is arranged on the guide columns; the turntable assembly is slidably sleeved on the guide columns and is located between the installation plate and the upper end plate.

[0009] Optionally, the limit sleeve is a plastic sleeve and is sleeved on the guide column.

[0010] Optionally, the turntable assembly includes a turntable base. A turntable is rotatably arranged on the lower end surface of the turntable base. A servo cam turntable for driving the turntable to rotate is arranged on the upper end surface of the turntable base. Quick-release locking parts for locking the nozzle assembly on the turntable are arranged at equal intervals in a circumferential array on the lower end surface of the turntable, and the quick-release locking parts are slidably clamped with the nozzle assembly; the output shaft of the servo cam turntable penetrates the turntable base and is fixedly connected to the turntable; four linkage rods for driving the turntable base to move up and down following the lifting frame are arranged on the upper end surface of the turntable base, and the ends of the linkage rods far from the turntable base are slidably clamped with the upper end plate.

[0011] Optionally, it further includes a water liquid solenoid valve; a cooling water channel is opened in the injection mold, the water inlet of the cooling water channel is communicated with the water outlet of the water liquid solenoid valve, the water outlet of the cooling water channel is communicated with the water return port of an external water conveying mechanism, and the water inlet of the water liquid solenoid valve is communicated with the water outlet of the external water conveying mechanism.

[0012] Optionally, the water liquid solenoid valve is a normally closed solenoid valve.

[0013] Optionally, the injection mold is a hot runner type mold.

[0014] The above embodiments of the present invention have the following beneficial effects compared with the prior art: The transmission structure composed of a synchronous pulley and a transmission belt is used to replace the speed reducer, and under the action of the servo motor and the lead screw, the lifting frame is driven to slide up and down on the frame, thereby reducing the working noise of the blow molding machine and providing a low-noise environment for employees. In addition, the servo cam turntable is used to replace the traditional linear servo speed reducer to drive the turntable to rotate, improving the levelness of the turntable and the accuracy of the stop angle, so that the stop angle error reaches ±0.05°. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic structural diagram of the present invention;

[0016] Figure 2 is a schematic structural diagram of the lifting frame and the turntable assembly in the present invention;

[0017] Figure 3 is a first schematic structural diagram of the turntable assembly in the present invention;

[0018] Figure 4 is a second schematic structural diagram of the turntable assembly in the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] In order to make the objectives, features, and advantages of the present invention more obvious and understandable, the following provides a detailed description of the specific embodiments of the present invention with reference to the accompanying drawings. Several embodiments of the present invention are shown in the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein.

[0020] The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0021] The present invention provides a low-noise one-step injection stretch blow molding machine, as Figures 1-4 shown, including a frame 1 and a transmission belt 13; an installation plate 11 is provided on the frame 1, and an injection mold 2 for forming a preform and a blow mold 3 for blowing the preform into a bottle body are provided on the installation plate 11. A lifting frame 4 that slides in the vertical direction is slidably provided on the installation plate 11. A turntable assembly 5 is slidably clamped in the middle of the lifting frame 4. At least three groups of nozzle assemblies 6 for adapting to the injection mold 2 to thermally form plastic into a preform and convey the preform to the blow mold 3 are provided on the turntable assembly 5; a lead screw 14 for driving the lifting frame 4 to slide up and down is rotatably provided in the frame 1. The lead screw 14 is threadedly connected to the lower end of the lifting frame 4; a synchronous pulley 15 is provided at the lower end of the lead screw 14, and a servo motor 12 is provided in the frame 1; one end of the transmission belt 13 is wound around the synchronous pulley 15, and the other end is wound around the output pulley of the servo motor 12; the lower end of the lifting frame 4 is located below the installation plate 11, and the upper end is located above the installation plate 11.

[0022] In this embodiment, the mounting plate 11 is mounted on the right end of the frame 1, and an injection molding machine (not shown in the drawings) is mounted on the left end of the frame 1. An injection mold 2 and a blow mold 3 are mounted on the mounting plate 1. The included angle between the injection mold 2 and the blow mold 3 is 120°. The lifting frame 4 is mounted on the mounting plate 11 in a manner of sliding in the vertical direction and is slidably connected to the frame 1. The turntable assembly 5 is mounted on the lifting frame 4 in a manner of sliding and clamping in the vertical direction; three nozzle assemblies 6 are equidistantly arranged in a circumferential array on the lower end surface of the turntable assembly 5. The servo motor 12, the transmission belt 13 and the lead screw 14 are mounted inside the frame 1. The two ends of the lead screw 14 are rotatably connected to the frame 1 through load-bearing bearings, and the synchronous pulley 15 is fixedly mounted at the bottom end of the lead screw 14. The servo motor 12 drives the lifting frame 4 to lift through the transmission of the transmission belt 13, the synchronous pulley 15 and the lead screw 14. Anti-slip teeth are provided on the outside of the synchronous pulley 15, the inside of the transmission belt 13 and the outside of the output pulley of the servo motor 12 to prevent transmission slippage.

[0023] The present invention uses the servo motor 12, the transmission belt 13, the lead screw 14 and the synchronous pulley 15 to form a power device for driving the lifting frame 4 to slide up and down on the frame 1. On the one hand, the nozzle assembly 6 is adapted to the injection mold 2 with a constant clamping pressure under the transmission of the turntable assembly 6, avoiding problems such as deformation, uneven wall thickness, and unstable bottle mouth size of the preform due to unstable clamping pressure when the voltage is unstable. On the other hand, the transmission structure composed of the synchronous pulley 15 and the transmission belt 13 is used to replace the speed reducer in the patent with the publication number CN119369691A. Under the action of the servo motor 12 and the lead screw 14, the lifting frame 4 is driven to slide up and down on the frame 1, thereby reducing the working noise of the blow molding machine and providing a low-noise environment for employees.

[0024] In addition, for the same stroke, the time for the servo to drive the lifting frame 4 to lift and lower is shorter (for example, the hydraulic time may be 5 seconds, while the servo only needs 2-3 seconds), thereby improving the production speed, increasing the output, and reducing the energy consumption.

[0025] Further, the lifting frame 4 includes an upper end plate 41 located above the mounting plate 11, a lower end plate 42 located below the mounting plate 11, and four guide columns 43 slidably connected to the mounting plate 11; the guide columns 43 penetrate through the mounting plate 11, and their upper ends are fixedly connected to the upper end plate 41, and their lower ends are fixedly connected to the lower end plate 42; a limit sleeve 44 for preventing the turntable assembly 5 from abutting against the upper end plate 41 is provided on the guide columns 43; the turntable assembly 5 is slidably sleeved on the guide columns 43 and is located between the mounting plate 11 and the upper end plate 41.

[0026] Further, the limit sleeve 44 is a plastic sleeve with a high elastic modulus and is sleeved on the guide column 43.

[0027] Further, the turntable assembly 5 includes a turntable base 51. A turntable 52 is rotatably arranged on the lower end face of the turntable base 51. A servo cam turntable 53 for driving the turntable 52 to rotate is arranged on the upper end face of the turntable base 51. Quick-release locking members 54 for locking the nozzle assembly 6 onto the turntable 52 are arranged in a circumferential array at equal intervals on the lower end face of the turntable 52. The quick-release locking members 54 are slidably clamped to the nozzle assembly 6. The output shaft of the servo cam turntable 53 passes through the turntable base 51 and is fixedly connected to the turntable 52. Four linkage rods 511 for driving the turntable base 51 to move up and down following the lifting frame 4 are arranged on the upper end face of the turntable base 51. One end of each linkage rod 511 away from the turntable base 51 is slidably clamped to the upper end plate 41.

[0028] As Figures 1-4 shown, the four guide posts 43 are respectively located at the four corner positions of the upper end plate 41. The upper ends of the four guide posts 43 are fixedly connected to the upper end plate 41 by screws, and the lower ends of the four guide posts 43 are fixedly connected to the lower end plate 42 by screws. Through holes corresponding to the guide posts 43 are formed in the turntable base 51, and the guide posts 43 are sleeved through these through holes, so that the turntable base 51 can slide between the upper end plate 41 and the lower end plate 42. The servo cam turntable 53 is installed on the upper end face of the turntable base 51. The output shaft of the servo cam turntable 53 passes downward through the turntable base 51 and is fixedly connected to the turntable 52 by an existing method. In the patent with the publication number CN119369691A, a servo motor is used to directly drive the turntable 52 to rotate. However, the servo motor does not have a large output torque and cannot quickly drive the turntable 52 to rotate during actual production. On the one hand, there is a lag and it is easy to be damaged (due to the large weight of the turntable 52). On the other hand, due to inertia, the turntable 52 cannot accurately stop at the preset position, resulting in a large error between the stopping angle of the turntable 52 and the preset position, and the preform cannot be accurately placed into the blow molding die 3, and there are large quality problems with the blown bottle body. To improve this problem, a servo reduction motor with a deceleration function can be selected for the servo motor. However, traditional servo reducers are generally linear servo reducers, which have the disadvantage of large volume, are not conducive to reducing the height of the equipment, and are prone to causing the turntable 52 to be high on one side and low on the other side (i.e., poor levelness), and have limited improvement in the quality of bottle blowing. The servo cam turntable 53 in the present application has the characteristics of high stability, high precision, high flexibility, zero backlash, etc., can improve production efficiency and reduce the failure rate, and is an ideal choice for the application of large-size and heavy-load equipment; using the servo cam turntable 53 to drive the turntable 52 to rotate instead of the traditional linear servo reducer in the prior art can improve the levelness of the turntable 42 and the accuracy of the stopping angle, and make the stopping angle error reach ±0.05°.

[0029] Three workstations are arranged in an equally spaced circular array on the lower end face of the turntable 52. At each workstation, a quick-release locking component 54 is fixedly installed by bolts. The turntable 52 is installed with three nozzle assemblies 6 through the quick-release locking components 54. The three nozzle assemblies 6 respectively correspond to the injection molding station, the blow molding station, and the part-taking station; the included angle between the injection molding station, the blow molding station, and the part-taking station is 120°. When producing the bottle body, the turntable base 51 moves downward under the drive of the lifting frame 4, so that the nozzle assembly 6 located at the injection molding station extends into the injection mold 2 to form a cavity for molding the preform with the injection mold 2. After the preform is molded, the nozzle assembly 6 fixes the preform by pressing against the mouth of the preform, and then the lifting frame 4 drives the turntable base 51 to move upward; then the servo cam turntable 53 drives the turntable 52 to rotate 120° to the blow molding station. The turntable base 51 moves downward under the drive of the lifting frame 4, so that the nozzle assembly 6 located at the blow molding station moves the preform into the blow mold 3 to blow the preform. After blow molding, the lifting frame 4 drives the turntable base 51 to move upward; then the servo cam turntable 53 drives the turntable 52 to rotate 120°, moves the bottle body obtained by blow molding to the part-taking station, and waits for the manipulator to take the part; then the steps of injection molding, blow molding, and part-taking are repeated in sequence.

[0030] The lower end of the linkage rod 511 is fixedly connected to the turntable base 51 by thread, and its upper end is slidably clamped to the upper end plate 41. When the lifting frame 4 is at the highest position, the upper end plate 41 clamps the linkage rod 511, and the upper surface of the upper end plate 41 is flush with the upper end of the linkage rod 511; when the lifting frame 4 is at the lowest position, the upper end of the linkage rod 111 protrudes above the upper end plate 41, and at this time the distance between the upper end plate 41 and the turntable base 51 is the smallest.

[0031] In the present invention, under the action of the linkage rod 511, the lifting frame 4 and the turntable assembly 5 only need a set of power mechanism for driving the lifting of the lifting frame (that is, the power mechanism composed of the servo motor 12, the transmission belt 13, the lead screw 14, and the synchronous pulley 15) during the process of blowing the preform into the bottle body. Compared with the blow molding machine in the patent of CN204431711 U, one set of power mechanism is saved, and the equipment cost is reduced.

[0032] The quick-release locking component 54, the nozzle assembly 6 and other component structures in the present application are the same as the structures disclosed in the patent of CN119369691A (the number of some components may be different). Since there is no improvement involved, it will not be elaborated here. For the specific structure, reference can be made to the patent of CN119369691A. The beneficial effects of the patent of CN119369691A are also possessed by the present application.

[0033] Further, it also includes a water solenoid valve (not shown in the drawings); a cooling water channel is provided in the injection mold 2, the water inlet of the cooling water channel is communicated with the water outlet of the water solenoid valve, the water outlet of the cooling water channel is communicated with the water return port of an external water delivery mechanism, and the water inlet of the water solenoid valve is communicated with the water outlet of the external water delivery mechanism.

[0034] Further, the water solenoid valve is a normally closed solenoid valve.

[0035] In this embodiment, the water solenoid valve is a conventional diaphragm type pilot solenoid valve with secondary valve opening, which is suitable for using water or other gas-liquids as the working medium and can automatically control or remotely control the on-off of working medium pipelines such as air, water, and oil liquids. The water inlet of the water solenoid valve is communicated with the water outlet of the external water delivery machine through a conduit, and its water outlet is communicated with the water inlet of the cooling water channel through a conduit; the water outlet of the cooling water channel is communicated with the water return port of the external water delivery machine through a conduit. The external water delivery machine is a conventional ice water machine used in the injection molding field and can output cooling water at a specific temperature. The cooling water enters the cooling water channel inside the injection mold through the water solenoid valve and the conduit, and then returns to the inside of the external water delivery machine through the conduit for temperature reduction treatment.

[0036] The water solenoid valve is a normally closed solenoid valve. When the injection mold is not in production, the water solenoid valve is normally closed, the cooling water channel is not supplied with water, the temperature of the injection mold 2 is close to the indoor temperature, and it is not easy to generate water mist or water droplets, thereby preventing the mold from rusting and improving the appearance yield of the product. When the injection mold 2 is in production (taking the time of the injection and holding pressure stages as the mold production time), the water solenoid valve is synchronously opened under the control of the PLC, the cooling water channel is supplied with water, and the injection mold is cooled. In order to quickly cool the injection mold, the water temperature is adjusted to 1 - 5°C (the traditional cooling water temperature is about 20°C). In the same time, the mold is cooled better, thereby shortening the cooling time and increasing the output. After a production cycle is completed, the power supply is immediately cut off and the water solenoid valve is closed. The specific power-on duration and power-on / off time of the water solenoid valve can be set on the PLC computer of the low-noise one-step injection stretch blow molding machine.

[0037] In this embodiment, by connecting a water solenoid valve to the cooling water channel of the injection mold 2, the water solenoid valve is in a normally closed state during the non-injection and holding pressure stages, the cooling water channel is not supplied with water inside, the temperature of the injection mold is close to the indoor temperature, and it is not easy to generate water mist or water droplets, thereby preventing the mold from rusting and improving the appearance yield of the product.

[0038] Further, in order to reduce plastic waste and scrap rate, and at the same time reduce the mold maintenance cost, the injection mold 2 adopts a hot runner type mold.

[0039] The above are only the preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions falling within the concept of the present invention belong to the protection scope of the present invention. It should be noted that for those of ordinary skill in the art, several improvements and refinements made without departing from the principle of the present invention should also be regarded as within the protection scope of the present invention.

Claims

1. A low-noise one-step injection stretch blow molding machine, characterized in that: It comprises a frame and a transmission belt; a mounting plate is arranged on the frame, an injection mold for forming a bottle blank and a blow mold for blowing the bottle blank into a bottle body are arranged on the mounting plate, a lifting frame sliding in a vertical direction is slidably arranged on the mounting plate, a turntable assembly is slidably engaged with the middle part of the lifting frame, and at least three groups of die nozzle assemblies for adapting to the injection mold to thermoform the plastic into a bottle blank and conveying the bottle blank to the blow mold are arranged on the turntable assembly; a screw rod for driving the lifting frame to slide up and down is rotatably arranged in the frame, and the screw rod is threadedly connected to the lower end of the lifting frame; a synchronous wheel is arranged at the lower end of the screw rod, and a servo motor is arranged in the frame; one end of the transmission belt is wound around the synchronous wheel, and the other end thereof is wound around the output wheel of the servo motor; the lower end of the lifting frame is located below the mounting plate, and the upper end thereof is located above the mounting plate.

2. The low-noise one-step injection stretch blow molding machine according to claim 1, characterized in that: The lifting frame includes an upper end plate located above the mounting plate, a lower end plate located below the mounting plate, and four guide columns slidably connected to the mounting plate; the guide columns penetrate the mounting plate, and their upper ends are fixedly connected to the upper end plate, and their lower ends are fixedly connected to the lower end plate; a limiting sleeve is provided on the guide column to prevent the turntable assembly from abutting the upper end plate; the turntable assembly is slidably sleeved with a guide column, and is located between the mounting plate and the upper end plate.

3. The low-noise one-step injection stretch blow molding machine according to claim 2, characterized in that: The limiting sleeve is a plastic sleeve and is sleeved on the guide column.

4. The low-noise one-step injection stretch blow molding machine according to claim 2, characterized in that: The turntable assembly includes a turntable seat, a turntable is rotatably arranged on the lower end surface of the turntable seat, a servo cam turntable is arranged on the upper end surface of the turntable seat for driving the turntable to rotate, and quick-release locking parts for locking the die nozzle assembly on the turntable are arranged in an evenly spaced circular array on the lower end surface of the turntable, and the quick-release locking parts are slidably engaged with the die nozzle assembly; the output shaft of the servo cam turntable passes through the turntable seat and is fixedly connected with the turntable; four linkage rods are arranged on the upper end surface of the turntable seat for driving the turntable seat to move up and down with the lifting frame, and the end of the linkage rod away from the turntable seat is slidably engaged with the upper end plate.

5. The low-noise one-step injection stretch blow molding machine according to claim 1, characterized in that: It also includes a water-liquid solenoid valve; a cooling water circuit is opened in the injection mold, the water inlet of the cooling water circuit is connected to the water outlet of the water-liquid solenoid valve, the water outlet of the cooling water circuit is connected to the return water port of the external water transport mechanism, and the water inlet of the water-liquid solenoid valve is connected to the water outlet of the external water transport mechanism.

6. The low-noise one-step injection stretch blow molding machine according to claim 5, characterized in that: The water solenoid valve is a normally closed solenoid valve.

7. The low-noise one-step injection stretch blow molding machine according to claim 5, characterized in that: The injection mold is a hot runner type mold.

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