A drawing rod for assisting bottle preform forming

Abstract

The present invention discloses a drawing rod for assisting in the forming of a bottle blank, comprising a rod body, a movable rod, and a supporting mechanism. The rod body is provided with a cavity, one end of the cavity is provided with a baffle, the baffle being provided with a through hole in the axial direction. One end of the movable rod is inserted into the cavity after passing through the through hole and moves axially along the cavity. A spring and a nut are mounted on the outside of the movable rod, with the two sides of the spring respectively abutting against the inner wall of the cavity and the nut. The supporting mechanism is arranged on the outside of the movable rod, comprising a push rod and a support rod, one end of the support rod being connected to the movable rod, the other end of the support rod being connected to the push rod, and the end of the push rod proximate the rod body being rotatably connected to the movable rod. When the movable rod moves axially, the support rod and the push rod are stretched outward or contracted inward, and the push rod is stretched outward so that the side wall of the bottle blank is radially stretched outward to assist in the forming of the bottle blank. The present invention has the advantages of radially stretching the side wall of the bottle blank to assist in the forming of the bottle blank, reducing the accumulation of material at the bottom or neck of the bottle blank, and meeting the requirements of the bottle blowing process.

Description

Technical Field

[0001] The invention belongs to the technical field of bottle blowing machines, and in particular relates to a drawing rod for assisting bottle blank forming. Background Art

[0002] A blow molding machine is a device that uses blow molding to form hollow containers from plastic pellets. Common models include extrusion blow molding machines, injection stretch blow molding machines, and stretch blow molding machines. PET preform stretch blow molding machines utilize a stretching rod to stretch the preform to assist in forming. Existing stretching rods in blow molding machines have the following issues: They only stretch the preform axially and are unable to stretch it radially to assist in forming. Imprecise blow molding techniques can easily lead to problems such as collapsed corners, flattened bottles, and oval bottles. Inadequate stretching of the bottle base or neck can also result in significant material buildup. Summary of the Invention

[0003] The purpose of the present invention is to solve the problems in the background technology and propose a drawing rod for assisting the forming of the bottle blank, which can radially stretch the side wall of the bottle blank to assist the forming of the bottle blank, reduce the accumulation of material at the bottom or neck of the bottle blank, better meet the requirements of the bottle blowing process, and avoid the occurrence of bottle corner collapse, deflated bottle, and oval bottle during the bottle blowing process.

[0004] To achieve the above-mentioned purpose, the present invention proposes a drawing rod for assisting in forming a preform, comprising:

[0005] A rod body, wherein a cavity is provided inside the rod body, a baffle is installed at one end of the cavity, and the baffle is provided with a through hole along the axial direction;

[0006] A movable rod, one end of which passes through the through hole and is inserted into the cavity and moves axially along the interior of the cavity. A spring and a nut are sleeved on the outer side of the movable rod. Two sides of the spring respectively abut against the inner wall of the cavity and the nut. The diameter of the nut is larger than the diameter of the through hole.

[0007] The supporting mechanism is arranged on the outside of the movable rod. The supporting mechanism includes a push rod and a support rod. One end of the support rod is connected to the movable rod, and the other end of the support rod is connected to the push rod. The end of the push rod close to the rod body is rotatably connected to the movable rod. When the movable rod moves axially, the support rod and the push rod are expanded outward or contracted inward. The push rod is expanded outward so that the side wall of the bottle blank is stretched radially outward to assist the bottle blank in molding.

[0008] Preferably, a groove for accommodating the support rod is provided on the inner side of the push rod, and one end of the support rod close to the rod body is rotatably installed in the groove corresponding to the push rod.

[0009] Preferably, a receiving portion is provided at one end of the movable rod away from the cavity, and a card slot is provided on the outside of the receiving portion. The card slots are arranged in a one-to-one correspondence with the push rods, and the push rods are snapped into the corresponding card slots after being retracted inwards.

[0010] Preferably, the end of the support rod away from the rod body and the end of the push rod close to the rod body are respectively installed on the outside of the movable rod with fastening rings, and the side walls of the support rod and the push rod are provided with fastening grooves for installing fastening rings.

[0011] Preferably, a raised portion is provided at the middle of one end of the push rod close to the rod body, a side wall of the raised portion is provided with a fastening groove for installing a fastening ring, and the width of the raised portion is smaller than the width of the push rod.

[0012] Preferably, the length of the ejector rod in the ejection mechanism and the outward extension distance are set according to the maximum radial stretching distance required at the corresponding position of the bottle blank side wall, the outer side surface of the end of the ejector rod away from the rod body is an arc-shaped surface, and the number of ejector rods in the ejection mechanism is set according to the direction in which the bottle blank side wall needs to be stretched.

[0013] Preferably, the cavity is arranged inside the lower end of the rod body, the longitudinal section of the cavity is convex, the upper end of the movable rod is slidably installed in the rod body, and the push rod in the supporting mechanism is pushed outward from bottom to top.

[0014] Preferably, the cavity is arranged inside the upper end of the rod body, the longitudinal section of the cavity is convex, the lower end of the movable rod is slidably installed in the rod body, and the top rod in the supporting mechanism is supported outward from top to bottom.

[0015] Preferably, the rod body includes a first rod body and a second rod body, the number of the movable rods is 2, and the two movable rods are an upper movable rod and a lower movable rod respectively. The two ends of the upper movable rod are connected to the first rod body and the second rod body respectively, and a cavity is provided inside the upper and lower ends of the first rod body. The two cavities are symmetrically arranged and the longitudinal cross-section of the cavity is convex. The upper end of the lower movable rod is slidably installed inside the lower end of the first rod body, and the top rod in the supporting mechanism on the outside of the lower movable rod is stretched outward from bottom to top. The lower end of the upper movable rod is slidably installed inside the upper end of the first rod body, and the top rod in the supporting mechanism on the outside of the upper movable rod is stretched outward from top to bottom.

[0016] Preferably, a limiting groove adapted to the nut is provided on the side of the baffle close to the spring, and a plurality of limiting columns are provided on the side of the baffle away from the spring, and the end of the push rod close to the rod body corresponds to the area between two adjacent limiting columns.

[0017] The beneficial effects of the present invention are as follows: the present invention arranges at least one movable rod and a top support mechanism on the drawing rod. The top support mechanism expands outward or contracts inward during the movement of the movable rod, so as to radially stretch the side wall of the bottle preform to assist in the forming of the bottle preform, thereby reducing the accumulation of material at the bottom or neck of the bottle preform. The arrangement of the top support mechanism can better and evenly blow bottles of various shapes, better meeting the requirements of the bottle blowing process.

[0018] The features and advantages of the present invention will be described in detail through embodiments with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural diagram of an embodiment of the present invention.

[0020] Figure 2 It is a front view of an embodiment of the present invention.

[0021] Figure 3 This is an embodiment of the present invention Figure 2 Cross-sectional view of the middle BB plane.

[0022] Figure 4 2 is a schematic diagram of a push rod according to an embodiment of the present invention.

[0023] Figure 5 2 is a schematic diagram of a movable rod according to an embodiment of the present invention.

[0024] Figure 6 It is a front view of the movable rod according to an embodiment of the present invention.

[0025] Figure 7 It is a bottom view of the movable rod according to an embodiment of the present invention.

[0026] Figure 8 Schematic diagram of a baffle according to an embodiment of the present invention.

[0027] Figure 9 It is a left sectional view of a baffle according to an embodiment of the present invention.

[0028] Figure 10 This is a schematic diagram of a usage state of an embodiment of the present invention.

[0029] Figure 11 This is a schematic diagram of a usage state of an embodiment of the present invention.

[0030] Figure 12 This is a schematic diagram of a usage state of an embodiment of the present invention.

[0031] In the figure: 1-rod body, 2-movable rod, 3-support mechanism, 4-spring, 5-nut, 6-baffle, 7-fastening ring, 8-bottle blank, 11-cavity, 21-storage portion, 22-slot, 31-lift rod, 32-support rod, 33-groove, 34-protrusion, 61-limiting column, 62-through hole. DETAILED DESCRIPTION

[0032] Example 1 see Figure 1 、 Figure 2 、 Figure 3 This embodiment provides a drawing rod for assisting in forming a preform, comprising:

[0033] The rod body 1 has a cavity 11 formed inside, a baffle 6 is installed at one end of the cavity 11, a through hole 62 is formed in the middle of the baffle 6 along the axial direction, and the baffle 6 is threadedly connected to the rod body 1;

[0034] The movable rod 2 has one end inserted into the cavity 11 after passing through the through hole and moves axially along the inside of the cavity 11. The outer side of the movable rod 2 is provided with a spring 4 and a nut 5. The two sides of the spring 4 respectively abut against the inner wall of the cavity 11 and the nut 5. The diameter of the nut 5 is larger than the diameter of the through hole 62.

[0035] The supporting mechanism 3 is arranged on the outside of the movable rod 2. The supporting mechanism 3 includes a push rod 31 and a support rod 32. One end of the support rod 32 is connected to the movable rod 2, and the other end of the support rod 32 is connected to the push rod 31. The end of the push rod 31 close to the rod body 1 is rotatably connected to the movable rod 2. When the movable rod 2 moves axially inside the cavity 11, the support rod 32 and the push rod 31 are expanded outward or contracted inward. The push rod 31 is expanded outward so that the side wall of the bottle blank 8 is stretched radially outward to assist the bottle blank 8 in forming.

[0036] See Figure 9 and Figure 10 The cavity 11 is arranged inside the lower end of the rod body. The longitudinal section of the cavity 11 is convex. The upper end of the movable rod 2 is slidably installed in the rod body 1. The ejector rod 31 in the supporting mechanism 3 is stretched outward from bottom to top. When the movable rod 2 moves axially, the upper end of the movable rod 2 is inserted into the cavity part with a smaller diameter in the cavity 11. The movable rod 2 is installed at the lower end of the rod body 1 to stretch the bottom of the bottle blank.

[0037] As an implementation option, see Figure 4 A groove 33 for accommodating the support rod 32 is provided on the inner side of the ejector rod 31. The end of the support rod 32 close to the rod body 1 is rotatably installed in the groove 33 corresponding to the ejector rod 31 by a pin. The support rod 32 is retracted in the groove of the ejector rod 31 to ensure the flatness of the outer surface of the drawing rod, making it convenient for the drawing rod to extend into the bottle blank.

[0038] As an example of an implementation method, see Figures 5 to 7 A receiving portion 21 is provided at the end of the movable rod 2 away from the cavity 11, and a card slot 22 is provided on the outside of the receiving portion 21. The card slot 22 is arranged in a one-to-one correspondence with the ejector rod 31. After the ejector rod 31 is retracted inward, it is snapped into the corresponding card slot 22. The card slot 22 can be used to accommodate the ejector rod 31, ensuring the flatness of the outer surface of the drawing rod and facilitating the insertion of the drawing rod into the preform.

[0039] As an implementable embodiment, the end of the support rod 32 away from the rod body 1 and the end of the top rod 31 close to the rod body 1 are respectively installed on the outside of the movable rod 2 with a fastening ring 7. The side walls of the support rod 32 and the top rod 31 are provided with fastening grooves for installing the fastening ring 7. The fastening ring 7 can be made of copper wire or hard rubber. The fastening grooves on multiple support rods 32 are distributed in concentric circles, and the fastening grooves on multiple top rods 31 are distributed in concentric circles, so that the support rods 32 and the top rod 31 can only rotate within a small range in the horizontal direction and cannot slide up and down.

[0040] As an implementable embodiment, a protrusion 34 is provided in the middle of one end of the push rod 31 close to the rod body 1, and a fastening groove is provided on the side wall of the protrusion 34 for installing the fastening ring 7. The width of the protrusion 34 is smaller than the width of the push rod 31. The protrusion 34 is inserted into one end of the baffle 6, and the push rod 31 is rotated under the obstruction of the baffle 6 and the limiting action of the fastening ring 7. The setting of the fastening groove facilitates the limiting installation of the fastening ring 7.

[0041] As an implementable embodiment, the length and outward stretching distance of the push rod 31 in the push-up mechanism 3 are set according to the maximum radial stretching distance required at the corresponding position of the side wall of the bottle blank 8. For example, the bottle blank 8 that needs to be stretched is an eccentric bottle, and the push rod 31 can be designed on one side or set on the long and short sides; the outer side surface of the end of the push rod 31 away from the rod body 1 is an arc-shaped surface, and the number of the push rods 31 in the push-up mechanism 3 is set according to the direction in which the side wall of the bottle blank 8 needs to be stretched. For example, if the bottle blank 8 that needs to be stretched has a five-petal bottom, five push rods 31 are distributed in the direction of the petals of the bottle bottom to better meet the production needs of different bottle types.

[0042] As an example of an implementation method, see Figure 8 and Figure 9 A limiting groove adapted to the nut 5 is provided on the side of the baffle 6 close to the spring 4, and a plurality of limiting posts 61 are provided on the side of the baffle 6 away from the spring 4. The end of the ejector pin 31 close to the rod body 1 corresponds to the area between two adjacent limiting posts 61. The limiting posts 61 play a certain limiting role on the ejector pin 31, preventing the ejector pin 31 from rotating too much, thereby ensuring the smooth storage of the ejector pin 31 and the accuracy of the stretching of the preform.

[0043] The working process of the drawing rod of Example 1: when it is necessary to stretch the neck of the bottle blank 8, the rod body 1 is extended into the bottle blank 8 and abuts against the inner wall of the bottom of the bottle blank 8. When the movable rod 2 is continued to be pressed, the lower half of the movable rod 2 is further inserted into the cavity 11, and the outer wall of the upper end of the ejector rod 31 abuts against the upper end of the baffle 6. The upper end of the ejector rod 31 rotates around the fastening ring 7, and the lower end of the ejector rod 31 rotates outward from bottom to top and stretches the bottom side wall of the bottle blank 8 outward, thereby extending the accumulated material at the bottom of the bottle blank 8 to both sides to reduce the accumulated material at the bottom of the bottle. 2 also rotates outward to support the ejector rod 31 for bottle blowing. When the ejector rod 31 needs to be retracted, the rod body 1 moves upward, and the movable rod 2 is separated from the bottle bottom. Under the elastic restoring action of the spring 4, the upper half of the movable rod 2 gradually moves out of the cavity 11, and the support rod 32 rotates toward the movable rod 2 and drives the ejector rod 31 to shrink inward from top to bottom until it returns to its initial state, pulling the blank rod out of the bottle mouth. The position of the nut on the movable rod 2 can be adjusted by screwing the nut 5, thereby adjusting the maximum moving distance of the movable rod 2 and the spring 4.

[0044] Example 2 see Figure 12 In this embodiment, except that the cavity 11 is set inside the upper end of the rod body 1, the longitudinal section of the cavity 11 is convex, the lower end of the movable rod 2 is slidably installed in the rod body 1, and the top rod 31 in the supporting mechanism 3 is stretched outward from top to bottom, the rest of the structure is the same as that of Example 1.

[0045] The support rod 32 rotates in the direction close to the movable rod 2 and drives the ejector rod 31 to retract inwardly from bottom to top until it returns to its original state, thereby pulling the blank out of the bottle mouth.

[0046] Example 3. In addition to the rod body 1 including the first rod body and the second rod body, this embodiment also includes 2 movable rods 2. The two movable rods 2 are respectively an upper movable rod and a lower movable rod. The two ends of the upper movable rod are connected to the first rod body and the second rod body respectively. A cavity 11 is provided inside the upper and lower ends of the first rod body. The two cavities 11 are symmetrically arranged and the longitudinal section of the cavity 11 is convex. The upper end of the lower movable rod is slidably installed inside the lower end of the first rod body. The push rod 31 in the supporting mechanism 3 on the outside of the lower movable rod is stretched outward from bottom to top. The lower end of the upper movable rod is slidably installed inside the upper end of the first rod body. The push rod 31 in the supporting mechanism 3 on the outside of the upper movable rod is stretched outward from top to bottom. The rest of the structure is the same as Example 1. By setting two sets of supporting mechanisms 3, it can assist in blowing out complex bottle shapes with different upper and lower offset angles, rotation and large size differences. The bottom and neck of the bottle blank 8 are stretched by the two sets of supporting mechanisms 3 to reduce material accumulation.

[0047] In the present invention, the number and position of the supporting mechanism 3 are set according to the requirements of bottle blank molding or material accumulation. For example, if there is a lot of material accumulation at the bottom of the bottle, the supporting mechanism 3 is set at the bottom of the drawing rod. If there is a lot of material accumulation at the neck of the bottle, the supporting mechanism 3 can be set in the middle of the drawing rod. The ejection angle of the ejector rod 31 is adjusted by the flat wire. The flat wire and the parallel reference surface for tightening the force with a wrench can be set at the upper part of the drawing rod to correspond to the required angle. After tightening the upper thread of the drawing rod, fine-tune the parallel reference surface to be parallel or perpendicular to the mold parting surface (determined according to the installation requirements of the machine model), and then lock the locking nut. This is the correct installation angle of the drawing rod corresponding to this bottle shape. The flat wire is a structure on the existing drawing rod and is not described in detail in the present invention.

[0048] The supporting mechanism 3 in the present invention can specifically assist the preform to stretch in one or more directions in advance, and the final formed bottle can selectively make some curved surfaces weaker, so as to achieve the effect of gathering internal pressure, opening up some bottle design ideas. When assisting the bottle body with a smaller diameter in the middle section and larger diameters at the upper and lower sections, a double supporting mechanism can be used to make the wall thickness of the smaller diameter part in the middle section thinner and the wall thickness of the larger diameter part in the upper and lower sections thicker, thereby gathering the negative pressure of refrigeration, so that the height of the bottle can be elastically shrunk without almost deforming the whole bottle body, and rebound after opening the cover. This method can not only avoid the collision deformation during transportation (relying on the larger diameter section to support the external force) but also alleviate the situation of the bottle being oval and deflated during refrigeration. A groove can also be designed on one side to achieve the interesting effect of "bending" during refrigeration and rebounding after opening the cover. In addition, the bottom part of the bottle can be axially stretched first (such as Figure 11As shown in FIG, the length of the support rod 32 can be adjusted during the design process to accommodate bottle bases of different shapes and functions. For example, a longer support rod 32 can overstretch the bottle base, thereby making the bottom wall thickness of the bottle base smaller than the circumference wall thickness of the bottle base (for use with a negative pressure-resistant base). When the support rod 32 is longer and the top support structure is positioned relatively upward, the PET material contained in the entire bottle base can be increased due to the expansion during the downward pressure of the drawing rod and the simultaneous downward pressure of the support rod, thereby meeting the design requirements of aesthetic molding such as "peaks" and "snowflakes" and protruding the bottle base higher.

[0049] Under the premise of meeting the requirements of limiting the spring 4 and preventing the movable rod 2 from falling off, other limiting components such as a retaining ring can be used to replace the nut 5.

[0050] The above embodiments are intended to illustrate the present invention, not to limit the present invention. Any solution that is a simple transformation of the present invention falls within the protection scope of the present invention.

Claims

1. A drawing rod for assisting preform forming, characterized in that: include: A rod body, wherein a cavity is provided inside the rod body, a baffle is installed at one end of the cavity, and the baffle is provided with a through hole along the axial direction; A movable rod, one end of which passes through the through hole and is inserted into the cavity and moves axially along the interior of the cavity. A spring and a nut are sleeved on the outer side of the movable rod. Two sides of the spring respectively abut against the inner wall of the cavity and the nut. The diameter of the nut is larger than the diameter of the through hole. The supporting mechanism is arranged on the outside of the movable rod. The supporting mechanism includes a push rod and a support rod. One end of the support rod is connected to the movable rod, and the other end of the support rod is connected to the push rod. The end of the push rod close to the rod body is rotatably connected to the movable rod. When the movable rod moves axially, the support rod and the push rod are expanded outward or contracted inward. The push rod is expanded outward so that the side wall of the bottle blank is stretched radially outward to assist the bottle blank in molding.

2. The drawing rod for assisting preform forming according to claim 1, characterized in that: A groove for accommodating the support rod is provided on the inner side of the push rod, and one end of the support rod close to the rod body is rotatably installed in the groove corresponding to the push rod.

3. The drawing rod for assisting preform forming according to claim 1, characterized in that: A receiving portion is provided at one end of the movable rod away from the cavity, and a clamping slot is provided on the outside of the receiving portion. The clamping slots are arranged in a one-to-one correspondence with the push rods, and the push rods are clamped into the corresponding clamping slots after being retracted inwards.

4. The drawing rod for assisting preform forming according to claim 1, characterized in that: The end of the support rod away from the rod body and the end of the push rod close to the rod body are respectively installed on the outside of the movable rod with fastening rings, and the side walls of the support rod and the push rod are provided with fastening grooves for installing the fastening rings.

5. The drawing rod for assisting preform forming according to claim 4, characterized in that: A raised portion is provided at the middle of one end of the push rod close to the rod body, and a fastening groove for installing a fastening ring is provided on the side wall of the raised portion. The width of the raised portion is smaller than the width of the push rod.

6. The drawing rod for assisting preform forming according to claim 1, characterized in that: The length and outward extension distance of the ejector rod in the ejection mechanism are set according to the maximum radial stretching distance required at the corresponding position of the bottle preform side wall. The outer side surface of the end of the ejector rod away from the rod body is an arc-shaped surface. The number of ejector rods in the ejection mechanism is set according to the direction in which the bottle preform side wall needs to be stretched.

7. The drawing rod for assisting preform forming according to claim 1, characterized in that: The cavity is arranged inside the lower end of the rod body, and the longitudinal section of the cavity is convex. The upper end of the movable rod is slidably installed in the rod body, and the push rod in the support mechanism is supported outward from bottom to top.

8. The drawing rod for assisting preform forming according to claim 1, characterized in that: The cavity is arranged inside the upper end of the rod body, and the longitudinal section of the cavity is convex-shaped. The lower end of the movable rod is slidably installed in the rod body, and the push rod in the support mechanism is supported outward from top to bottom.

9. The drawing rod for assisting preform forming according to claim 1, characterized in that: The rod body includes a first rod body and a second rod body, and the number of the movable rods is 2, and the two movable rods are an upper movable rod and a lower movable rod respectively. The two ends of the upper movable rod are connected to the first rod body and the second rod body respectively. A cavity is provided inside the upper and lower ends of the first rod body. The two cavities are symmetrically arranged and the longitudinal cross-section of the cavity is convex. The upper end of the lower movable rod is slidably installed inside the lower end of the first rod body, and the top rod in the supporting mechanism on the outside of the lower movable rod is stretched outward from bottom to top. The lower end of the upper movable rod is slidably installed inside the upper end of the first rod body, and the top rod in the supporting mechanism on the outside of the upper movable rod is stretched outward from top to bottom.

10. The drawing rod for assisting preform forming according to claim 1, characterized in that: The side of the baffle close to the spring is provided with a limiting groove adapted to the nut, and the side of the baffle away from the spring is provided with a plurality of limiting columns, and the end of the push rod close to the rod body corresponds to the area between two adjacent limiting columns.

Images