A blow molding mechanism with synchronous linkage of sealing and stretching

Abstract

The present invention relates to a blow molding mechanism with synchronous linkage of sealing and stretching, which includes a fixed plate, a sealing component and a stretching component both installed on the fixed plate, and a linkage driving component installed on the fixed plate; the linkage driving component includes a motor installed on the fixed plate, a turntable connected to the output end of the motor, a needle roller cam guide, a gear connected to the turntable, and a rack installed on the fixed plate; a chute is provided on the end face of the turntable, the needle roller cam guide is located in the chute and the needle roller cam guide slides relative to the turntable, the circumferential side surface of the needle roller cam guide fits with the inner wall of the chute, the rack meshes with the gear, the chute has an arc groove section and a straight groove section, the arc groove section and the straight groove section are connected, the center of the arc groove section is the same as the center of the turntable, the distance from the arc groove section to the center of the turntable is greater than the distance from the straight groove section to the center of the turntable, the rack is connected to the stretching component, and the needle roller cam guide is connected to the sealing component. The present invention belongs to the field of blow molding mechanisms.

Description

Technical Field

[0001] The present invention relates to a blow molding mechanism, and more particularly to a blow molding mechanism in which sealing and stretching are synchronously linked. Background Art

[0002] Blow molding, also known as hollow blow molding, is a rapidly developing plastic processing method. Plastics suitable for blow molding include polyethylene, polyvinyl chloride, polypropylene, polyester, etc., and the resulting hollow containers are widely used as industrial packaging containers. According to the method of making the preform, blow molding can be divided into extrusion blow molding and injection blow molding. Newly developed ones include multi-layer blow molding and stretch blow molding. In the actual production process, stretch blow molding generally seals the preform first and then blows and stretches the preform. This will cause the blow molding mechanism to be asynchronous during the sealing and stretching processes, reducing production efficiency. At the same time, since a cylinder is used for driving in the existing technology, the cylinder requires a certain response process, making it easy for the coordination of the two productions of sealing and stretching to have errors. For example, if the sealing response is slow and the stretching response is fast, the production quality will decline, and even defective products will be produced. Summary of the Invention

[0003] Aiming at the technical problems existing in the prior art, the object of the present invention is to provide a blow molding mechanism in which sealing and stretching are synchronously linked. The blow molding mechanism has a simple structure, and the sealing and stretching are carried out synchronously, improving the production efficiency while ensuring the production quality.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] A blow molding mechanism in which sealing and stretching are synchronously linked includes a fixed plate, a sealing assembly and a stretching assembly that are both slidably installed on the fixed plate, and a linkage driving assembly installed on the fixed plate; the linkage driving assembly includes a motor installed on the fixed plate, a turntable fixedly connected to the output end of the motor, a needle roller cam guide installed on the turntable, a gear fixedly connected to the turntable, and a rack slidably installed on the fixed plate; the rotation centers of the turntable and the gear are the same and rotate synchronously. A chute is provided on the end face of the turntable. The needle roller cam guide is located in the chute and the needle roller cam guide slides relative to the turntable. The circumferential side surface of the needle roller cam guide fits with the inner wall of the chute. The rack meshes with the gear. The chute has an arc groove section and a straight groove section, and the arc groove section and the straight groove section are connected. The center of the arc groove section is the same as the center of the turntable. The distance from the arc groove section to the center of the turntable is greater than the distance from the straight groove section to the center of the turntable. The rack is fixedly connected to the stretching assembly, and the needle roller cam guide is fixedly connected to the sealing assembly. Driven by the motor, the turntable drives the sealing assembly and the stretching assembly to move downward at the same time, and the stroke of the sealing assembly is controlled by the chute, so that the blow molding mechanism seals and stretches the preform in sequence.

[0006] Furthermore, a guide rail is fixed on the fixed plate, a first slider and a second slider are slidably mounted on the guide rail, the sealing assembly and the stretching assembly are slidably mounted on the guide rail through the first slider and the second slider, respectively, and the sealing assembly is located below the stretching assembly. The guide rail can guide the sealing assembly and the stretching assembly to move up and down.

[0007] Furthermore, the sealing assembly includes a connecting block fixedly connected to the needle roller cam guide, a first sliding frame fixedly connected to the connecting block, and a sealing unit installed on the first sliding frame; the first sliding frame is fixed on the first sliding block. The sealing assembly can seal the bottle mouth of the bottle blank.

[0008] Furthermore, there are a plurality of sealing units, which are evenly distributed horizontally along the second sliding frame, and the sealing units include a sealing cylinder installed on the first sliding frame and a sealing preform head fixedly connected to the output end of the sealing cylinder. The plurality of sealing units seal a plurality of preforms at the same time, thereby improving production efficiency.

[0009] Furthermore, the stretching assembly includes a second sliding frame fixed on the second slider, a pull rod fixed on the second sliding frame; the rack is fixedly connected to the second sliding frame, one end of the pull rod is fixed on the second sliding frame, and the other end of the pull rod passes through the sealing cylinder and the sealing preform head in sequence, and there are a plurality of pull rods, which correspond to a plurality of sealing units. After the sealing assembly seals the bottle mouth of the preform, the pull rod of the stretching assembly performs blow molding and stretching on the preform.

[0010] Furthermore, the blow molding mechanism with synchronous linkage between sealing and stretching also includes a first anti-collision block, a first limit block and a second limit block; the first anti-collision block is fixed on the first sliding frame and is located between the first sliding frame and the second sliding frame, the first limit block is fixed on the fixed plate and is located below the first sliding frame, and the second limit block is fixed on the fixed plate and is located above the second sliding frame. The first anti-collision block can prevent the sealing component and the stretching component from colliding, and the first limit block and the second limit block limit the first sliding frame and the second sliding frame respectively to prevent the first sliding frame and the second sliding frame from detaching from the guide rail.

[0011] Furthermore, the blow molding mechanism with synchronous sealing and stretching also includes a guide column, which is fixed on the fixed plate, and a bearing is rotatably mounted on the guide column, and the circumferential side of the bearing is tangent to the side of the rack. The guide column guides the rotation of the turntable, and the bearing can guide the rack to slide up and down while preventing the rack from deviating in the horizontal direction.

[0012] Furthermore, the fixing plate is also provided with positioning keys, and there are two positioning keys and two guide rails, the two guide rails are parallel to each other, the turntable is located between the two guide rails, and the two positioning keys are respectively located beside the two guide rails and in contact with the guide rails. The positioning keys can prevent the guide rails from deflecting.

[0013] Further, the blow molding mechanism with synchronous linkage of sealing and stretching further includes a first detection switch for detecting the position of the first sliding frame and a second detection switch for detecting the position of the second sliding frame; both the first detection switch and the second detection switch are fixed on the fixed plate. The first detection switch and the second detection switch can respectively detect whether the first sliding frame and the second sliding frame return to the origin.

[0014] Further, the diameter of the needle roller cam guide is equal to the width of the chute. One end of the arc chute section is connected to one end of the straight chute section, and the other end of the arc chute section is tangent to and not connected to the other end of the straight chute section. The needle roller cam guide slides along the chute. During the sliding process, by controlling the distance from the needle roller cam guide to the center of the turntable, the sealing assembly is lowered or remains stationary.

[0015] Generally speaking, the present invention has the following advantages:

[0016] The blow molding mechanism with synchronous linkage of sealing and stretching can perform sealing and stretching on the preform synchronously. Through one motor, the sealing and stretching can be carried out synchronously. While realizing the simultaneous start of the sealing assembly and the stretching assembly, it also realizes the sequential progress of the sealing and stretching operations. The sealing and stretching of this blow molding mechanism are carried out synchronously, solving the problems of slow response and instability of pneumatic and other driving methods. At the same time, it also avoids the problem of the decline in the matching accuracy of the two processes of sealing and stretching when different driving methods are used for driving respectively. This blow molding mechanism has a simple structure, can improve production efficiency while ensuring the quality of production. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic structural diagram of the blow molding mechanism with synchronous linkage of sealing and stretching.

[0018] Figure 2 is a schematic structural diagram of the fixed plate, the linkage drive assembly, the stretching assembly, and the guide rail.

[0019] Figure 3 is a schematic structural diagram of the fixed plate, the linkage drive assembly, and the first limit block.

[0020] Figure 4 is Figure 2 a schematic structural diagram of the structure at position A in

[0021] Figure 5 is a schematic structural diagram of the turntable. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] The following will further describe the present invention in detail in conjunction with the drawings and specific embodiments.

[0023] For the convenience of uniformly viewing each reference numeral in the drawings of the specification, the reference numerals appearing in the drawings of the specification are uniformly described as follows:

[0024] 1 is a fixed plate, 2 is a motor, 3 is a turntable, 4 is a switch bracket, 5 is a needle roller cam guide, 6 is a gear, 7 is a rack, 8 is a chute, 9 is a guide rail, 10 is a first slider, 11 is a second slider, 12 is a connecting block, 13 is a first sliding frame, 14 is a sealing unit, 15 is a second sliding frame, 16 is a pull rod, 17 is a first anti-collision block, 18 is a first limit block, 19 is a second limit block, 20 is a guide post, 21 is a bearing, 22 is a positioning key, 23 is a first detection switch, 24 is a second detection switch, 8-1 is an arc groove section, 8-2 is a straight groove section, 14-1 is a sealing cylinder, 14-2 is a sealing blank head.

[0025] Combined with Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5As shown in the figure, a blow molding mechanism with synchronous linkage of sealing and stretching includes a fixed plate, a sealing component and a stretching component that are both slidably installed on the fixed plate, and a linkage driving component installed on the fixed plate; the sealing component and the stretching component can slide up and down under the drive of the linkage driving component, and the sealing component is located below the stretching component. The linkage driving component includes a motor installed on the fixed plate, a turntable fixedly connected to the output end of the motor, a needle roller cam guide installed on the turntable, a gear fixedly connected to the turntable, and a rack slidably installed on the fixed plate; the body of the motor is fixedly installed on the fixed plate, a rotating shaft is provided at the center of the turntable, and the output end of the motor is fixedly connected to the rotating shaft of the turntable through a coupling. When the motor rotates, it drives the turntable to rotate synchronously. The centers of rotation of the turntable and the gear are the same and they rotate synchronously. A chute is provided on the end face of the turntable, the gear is fixed on the end face of the turntable, both the chute and the gear are located on the same end face of the turntable, and the gear is surrounded by the chute. The needle roller cam guide is located in the chute and the needle roller cam guide slides relative to the turntable. The circumferential side surface of the needle roller cam guide is in contact with the inner walls on both sides of the chute, and the needle roller cam guide can only roll along the length direction of the chute. The rack is fixedly connected to the stretching component, and the needle roller cam guide is fixedly connected to the sealing component. The upper end of the rack is connected to the stretching structure, and the rack meshes with the gear. When the turntable drives the gear to rotate, on the one hand, the sealing component is driven to move up and down by the needle roller cam guide sliding in the chute; on the other hand, the stretching component is driven to move up and down by the gear and the rack, realizing that one motor can drive the sealing component and the stretching component to move simultaneously. The chute has an arc groove section and a straight groove section, and the arc groove section and the straight groove section are connected. The needle roller cam guide on the needle roller cam guide can roll from the arc groove section to the straight groove section, or from the straight groove section to the arc groove section. The center of the arc groove section is the same as the center of the turntable, that is, when the needle roller cam guide rolls in the arc groove section, the distance from the needle roller cam guide to the center of the turntable remains unchanged. Thus, when the needle roller cam guide slides relative to the turntable (the turntable rotates and the position of the needle roller cam guide remains unchanged), the needle roller cam guide can stay in the same position, and the needle roller cam guide is always located at a position close to the lower circumferential side surface of the turntable. The distance from the arc groove section to the center of the turntable is greater than the distance from the straight groove section to the center of the turntable. When the needle roller cam guide moves from the arc groove section to the straight groove section, the needle roller cam guide is closer to the center of the turntable. However, the center of the turntable is fixed, so the needle roller cam guide will move upward, thereby driving the sealing component to move upward; conversely, when the needle roller cam guide rolls from the straight groove section to the arc groove section, the needle roller cam guide will move downward, thereby driving the sealing component to move downward.

[0026] The straight groove section is inclined, that is, when the needle roller cam guide is at different positions on the straight groove section, the distance from the needle roller cam guide to the center of the turntable is different. When the needle roller cam guide slides on the straight groove section and approaches the arc groove section, the needle roller cam guide is farthest from the center of the turntable, and the sealing component moves downward to the lower limit position; when the needle roller cam guide moves away from the arc groove section, the needle roller cam guide is closest to the center of the turntable, and the sealing component moves upward to the upper limit position.

[0027] When the needle roller cam guide rolls in the arc groove section, the distance from the needle roller cam guide to the center of the turntable remains unchanged, and the sealing component does not move up and down. However, the turntable still rotates, and the gear and the rack still drive the stretching component to move.

[0028] A guide rail is fixedly arranged on the fixed plate. A first slider and a second slider are slidably installed on the guide rail. The sealing component and the stretching component are respectively slidably installed on the guide rail through the first slider and the second slider. The sealing component is located below the stretching component. The guide rail is vertically arranged, and the first slider is located below the second slider.

[0029] The sealing component includes a connecting block fixedly connected to the needle roller cam guide, a first sliding frame fixedly connected to the connecting block, and a sealing unit installed on the first sliding frame; the first sliding frame is horizontally installed, the first sliding frame is fixedly connected to the needle roller cam guide through the connecting block, the first sliding frame is fixed on the first slider, and the first sliding frame is installed on the guide rail through the first slider. The guide rail restricts the first sliding frame to only slide up and down, so that the needle roller cam guide cannot move horizontally (left and right), and the needle roller cam guide always remains below the gear.

[0030] There are several sealing units. The several sealing units are horizontally and evenly distributed along the second sliding frame. The sealing unit includes a sealing cylinder installed on the first sliding frame and a sealing embryo head fixedly connected to the output end of the sealing cylinder. Arranging multiple sealing units can seal multiple preforms simultaneously, improving production efficiency.

[0031] The stretching component includes a second sliding frame fixed on the second slider and a pull rod fixed on the second sliding frame; the rack is vertically arranged, one side of the rack is provided with teeth, the upper end of the rack is fixedly connected to the second sliding frame. When the turntable rotates, the gear drives the rack to move up and down, thereby driving the second sliding frame to move up and down along the guide rail. One end of the pull rod is fixed on the second sliding frame, and the other end of the pull rod passes through the sealing cylinder and the sealing embryo head from top to bottom. There are several pull rods, and the several pull rods correspond to the several sealing units one by one, realizing simultaneous sealing and stretching of multiple preforms, improving production efficiency. The sealing unit and the stretching component are prior arts, and their structures are not described in detail here.

[0032] The blow molding mechanism with synchronous linkage of sealing and stretching further includes a first anti-collision block, a first limit block and a second limit block; the first anti-collision block is fixed on the upper end surface of the first sliding frame and is located between the first sliding frame and the second sliding frame, and the first anti-collision block prevents the first sliding frame from colliding with the second sliding frame. The first limit block is fixed on the fixed plate and is located below the first sliding frame, and the first limit block prevents the first sliding frame from sliding downward beyond the stroke range and disengaging from the guide rail, preventing damage to the sealing component. The second limit block is fixed on the fixed plate and is located above the second sliding frame, and the second limit block prevents the second sliding frame from sliding upward beyond the stroke range and disengaging from the guide rail, preventing damage to the stretching component.

[0033] The blow molding mechanism with synchronous linkage of sealing and stretching further includes a guide post; the guide post can prevent the rack from shifting laterally. The guide post is fixed on the fixed plate, and a bearing is rotatably installed on the guide post. The circumferential side surface of the bearing is tangent to the side surface of the rack. The distance between the bearing and the gear only allows the rack to slide up and down, restricting the lateral movement of the rack, so that the rack is always meshed with the gear. The bearing also makes the up and down movement of the rack easier through its own rotation.

[0034] Two positioning keys are also fixed on the fixed plate. There are two guide rails, and the two guide rails are parallel to each other. The turntable is located between the two guide rails. The two positioning keys are respectively located beside the two guide rails and are in contact with the guide rails. The positioning keys can prevent the guide rails from shifting laterally, so that the two guide rails always remain vertical. Each of the two guide rails has a first slider and a second slider. The sealing component and the stretching component are guided by the two guide rails to move up and down, making the movement of the sealing component and the stretching component smoother and the force more balanced.

[0035] The blow molding mechanism with synchronous linkage of sealing and stretching further includes a first detection switch for detecting the position of the first sliding frame and a second detection switch for detecting the position of the second sliding frame; both the first detection switch and the second detection switch are fixed on the fixed plate through a switch bracket. The first detection switch is close to the lower end of the guide rail, and the first detection switch can detect the position when the sealing component moves to the lowest point. The second detection switch is close to the upper end of the guide rail, and the second detection switch can detect the position when the stretching component moves to the highest point. During the working process, when the moving component of the sealing component or the stretching component is abnormal, the blow molding mechanism will automatically stop running and issue an alarm.

[0036] The diameter of the needle roller cam guide is equal to the width of the chute, ensuring that the needle roller cam guide can only roll along the length direction of the chute and ensuring the uniqueness of the rolling direction of the needle roller cam guide. One end of the arc chute section is connected to one end of the straight chute section (the end farthest from the center of the turntable); the other end of the arc chute section is tangent to and not connected to the other end of the straight chute section (the end closest to the center of the turntable). When the needle roller cam guide slides to the other end of the straight chute section (the end closest to the center of the turntable), it reaches the limit position. The rolling of the needle roller cam guide in the chute is not a circular motion but a reciprocating motion.

[0037] The working principle of the blow molding mechanism with synchronous linkage of sealing and stretching:

[0038] The origin position of the blow molding mechanism is as follows: the sealing component and the stretching component are located at the upper limit position of the guide rail, and the needle roller cam guide is located at the end of the straight groove section of the chute (i.e., away from the arc groove section, and at this time the needle roller cam guide is closest to the rotation center of the turntable). First, start the blow molding mechanism. Driven by the motor, the turntable and the gear rotate synchronously. When the turntable drives the stretching component to move downward, the needle roller cam guide slides from the straight groove section to the arc groove section. When the needle roller cam guide moves in the straight groove section, the needle roller cam guide will slowly move away from the turntable center, so that the needle roller cam guide drives the sealing component to slide downward to approach the preform and seal the bottle mouth, realizing the simultaneous downward movement of the sealing component and the stretching component. After the sealing component seals the bottle mouth, the sealing component no longer needs to move downward. At this time, when the needle roller cam guide slides into the arc groove section and slides in the arc groove section, the distance between the needle roller cam guide and the turntable center remains unchanged. At this time, the needle roller cam guide no longer moves downward, so that the sealing component remains stationary, but the gear and the rack still drive the stretching component to move downward to stretch the preform, enabling the blow molding mechanism to complete the sealing and stretching processes in sequence. After completing the sealing and stretching, the turntable rotates in reverse. The needle roller cam guide first slides along the arc groove section, and the distance between the needle roller cam guide and the turntable center remains unchanged. The sealing component remains stationary temporarily, but the gear and the rack drive the stretching component to move upward at this time. When the needle roller cam guide slides into the straight groove section, the distance between the needle roller cam guide and the turntable center gets closer and closer, thus realizing the upward movement of the sealing component and the stretching component together, and realizing one working cycle. By using the same motor to drive the sealing component and the stretching component to move up and down simultaneously, and at the same time, due to the design of the chute, the moving strokes of the sealing component and the stretching component are different, enabling the sealing and stretching actions to be carried out successively, ensuring the sequence of the process. When each of the sealing component and the stretching component uses one drive, it is easy to cause the problem that the sealing and stretching actions are difficult to accurately cooperate. Especially when using a cylinder or a hydraulic cylinder, due to the need for a certain response time for the cylinder or the hydraulic cylinder, it is easy to cause a starting time error. When the preform is sealed and stretched, the time of one working cycle is very short. If the previous action responds slowly, the next action will be affected, resulting in a change in the sequence of the process, affecting the production quality, and even producing scrapped products.

[0039] The above embodiments are the preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A blow molding mechanism with synchronous linkage of sealing and stretching, characterized in that: It includes a fixed plate, a sealing component and a stretching component that are both slidably installed on the fixed plate, and a linkage driving component installed on the fixed plate; the linkage driving component includes a motor installed on the fixed plate, a turntable fixedly connected to the output end of the motor, a needle roller cam guide installed on the turntable, a gear fixedly connected to the turntable, and a rack slidably installed on the fixed plate; the rotation centers of the turntable and the gear are the same and rotate synchronously. There is a chute on the end face of the turntable. The needle roller cam guide is located in the chute and the needle roller cam guide slides relative to the turntable. The circumferential side of the needle roller cam guide fits against the inner wall of the chute. The rack meshes with the gear. The chute has an arc groove section and a straight groove section, and the arc groove section and the straight groove section are connected. The center of the arc groove section is the same as the center of the turntable. The distance from the arc groove section to the center of the turntable is greater than the distance from the straight groove section to the center of the turntable. The rack is fixedly connected to the stretching component, and the needle roller cam guide is fixedly connected to the sealing component; A guide rail is fixedly installed on the fixed plate. A first slider and a second slider are slidably installed on the guide rail. The sealing component and the stretching component are respectively slidably installed on the guide rail through the first slider and the second slider. The sealing component is located below the stretching component; The blow molding mechanism with synchronous linkage of sealing and stretching further includes a guide post; the guide post is fixed on the fixed plate, and a bearing is rotatably installed on the guide post. The circumferential side of the bearing is tangent to the side of the rack.

2. A blow molding mechanism with synchronous linkage of sealing and stretching according to claim 1, characterized in that: The sealing component includes a connecting block fixedly connected to the needle roller cam guide, a first sliding frame fixedly connected to the connecting block, and a sealing unit installed on the first sliding frame; the first sliding frame is fixed on the first slider.

3. A blow molding mechanism with synchronous linkage of sealing and stretching according to claim 1, characterized in that: There are several sealing units, and several sealing units are evenly distributed along the horizontal direction of the first sliding frame. The sealing unit includes a sealing cylinder installed on the first sliding frame and a sealing blank head fixedly connected to the output end of the sealing cylinder.

4. A blow molding mechanism with synchronous linkage of sealing and stretching according to claim 3, characterized in that: The stretching component includes a second sliding frame fixed on the second slider and a pull rod fixed on the second sliding frame; the rack is fixedly connected to the second sliding frame. One end of the pull rod is fixed on the second sliding frame, and the other end of the pull rod passes through the sealing cylinder and the sealing blank head in sequence. There are several pull rods, and several pull rods correspond to several sealing units one by one.

5. A blow molding mechanism with synchronous linkage of sealing and stretching according to claim 4, characterized in that: The blow molding mechanism with synchronous linkage of sealing and stretching further includes a first anti-collision block, a first limit block and a second limit block; the first anti-collision block is fixed on the first sliding frame and is located between the first sliding frame and the second sliding frame. The first limit block is fixed on the fixed plate and is located below the first sliding frame. The second limit block is fixed on the fixed plate and is located above the second sliding frame.

6. A blow molding mechanism with synchronous linkage of sealing and stretching according to claim 1, characterized in that: A positioning key is also fixedly arranged on the fixed plate. There are two positioning keys and two guide rails. The two guide rails are parallel to each other. The turntable is located between the two guide rails. The two positioning keys are respectively located beside the two guide rails and in contact with the guide rails.

7. A blow molding mechanism with synchronous linkage of sealing and stretching according to claim 1, characterized in that: The blow molding mechanism with synchronous linkage of sealing and stretching further includes a first detection switch for detecting the position of the first sliding frame and a second detection switch for detecting the position of the second sliding frame; the first detection switch and the second detection switch are both fixed on the fixed plate.

8. A blow molding mechanism with synchronous linkage of sealing and stretching according to claim 1, characterized in that: The diameter of the needle roller cam guide is equal to the width of the chute. One end of the arc chute section is communicated with one end of the straight chute section. The other end of the arc chute section is tangent to the other end of the straight chute section and not communicated.

Images