A seamless screw head assembly and installation method thereof

Abstract

The present invention relates to a seamless screw head assembly and an installation method thereof, wherein the screw head assembly comprises a screw head, a meson, a check ring and a glue head, wherein the meson is fixed to the screw head, the glue head is sleeved at one end of the screw head, the check ring is sleeved on the screw head and is located between the glue head and the meson, one end of the screw head is provided with an external threaded portion and a front guide in sequence, the middle part of the glue head is provided with an internal threaded portion and a glue head sealing guide, wherein the external threaded portion and the internal threaded portion match each other, the glue head sealing guide is sleeved outside the front guide, and the front guide and the glue head sealing guide are interference fit by heat sleeve. The screw head assembly of the present invention can solve the problem of heterochromaticity of injection molded products, and has low cost.

Description

Technical Field

[0001] The invention relates to the technical field of injection molding accessories, and in particular to a seamless screw head assembly and an installation method thereof. Background Art

[0002] Nowadays, injection molded products have become more and more widespread, and the products have higher and higher requirements for mechanical equipment, molds, raw materials, processes and environment. Among them, the requirements for transparent, white and brightly colored products are the most prominent. The products must not have black spots, black lines, different colors, yellowing, discoloration, mixed colors, crystal points and other impurities and foreign matter, etc. These are basically the most troublesome and difficult to solve problems for product manufacturers. After research, it was found that many of the black spots, black lines, yellowing and different colors are mainly caused by the following two reasons: (1) After the rubber head and the screw head are tightened, there is a gap in the thread gap between the two, and air is left inside; (2) After the piezo on the screw head and the screw are tightened, there is still a gap between the piezo and the screw, which allows the air between the screw head and the screw to overflow. The above two parts of air expand and overflow due to heat during the injection molding process, resulting in black spots, black lines, yellowing, different colors, etc. on the product.

[0003] To solve the above problems, Chinese patent CN205202045U discloses a PC material anti-return structure, which eliminates the three components of the screw head, the meson and the glue head, and instead integrates them at one end of the screw, thus avoiding the problem of gaps between the screw head, the meson and the glue head. However, since the screw head is a wearing part, it will generally wear out every 3 to 6 months and need to be replaced. If the above integrated technical solution is adopted, once the screw head is worn, the entire screw needs to be replaced, which is very costly.

[0004] Therefore, there is an urgent need in the art for a screw head assembly that can solve the problem of yellowing and discoloration of products and has low cost. Summary of the invention

[0005] The purpose of the present invention is to provide a seamless screw head assembly in order to overcome the defects of the prior art.

[0006] The purpose of this application is also to provide a method for installing the above-mentioned screw head group.

[0007] In order to achieve the purpose of the present invention, this application provides the following technical solutions.

[0008] In the first aspect, the present application provides a seamless screw head group, the screw head group includes a screw head, a meson, a check ring and a glue head, the meson is fixed to the screw head, the glue head is sleeved at one end of the screw head, the check ring is sleeved on the screw head and is located between the glue head and the meson, one end of the screw head is provided with an external threaded portion and a front guide in sequence, the middle part of the glue head is provided with an internal threaded portion and a glue head sealing guide, wherein the external threaded portion and the internal threaded portion match each other, the glue head sealing guide is sleeved outside the front guide, and the front guide and the glue head sealing guide are interference fit by heat sleeve. Under normal conditions, the inner diameter of the glue head sealing guide is smaller than the outer diameter of the front guide. During installation, the glue head is heated to expand so that the inner diameter of the glue head sealing guide is larger than the outer diameter of the front guide, and the glue head sealing guide is sleeved outside the front guide. After the glue head is cooled, the glue head sealing guide shrinks, thereby achieving interference fit with the front guide. Since the sealing guide of the rubber head and the front guide are in a state of interference fit, the air between the external thread part and the internal thread part cannot escape, thereby ensuring the quality of the product.

[0009] In one embodiment of the first aspect, the meson is coaxially arranged on the screw head. The meson used in the present application is different from the existing meson. The meson of the present application and the screw head are integrally formed, that is, they are directly formed by mechanical processing. The one-piece design reduces many problems of matching errors and processing errors of multiple split parts in the past, and can ensure that the tail end plane of the meson is perpendicular to the axis of the screw head. When the screw head is screwed into the screw, the meson of the present application can fit completely with the top of the screw to play a sealing role, thereby preventing the air between the screw head and the screw from overflowing and ensuring product quality.

[0010] In one embodiment of the first aspect, the outer wall of the glue head is tapered at the head and the outer wall tail is a wrench position. The so-called wrench position means that the outer wall is in a regular hexagon or regular octagon shape, ensuring that a wrench can be directly applied thereon.

[0011] In one embodiment of the first aspect, the angle of the tapered outer wall head of the laminating head is 10 to 120 degrees. The angle of the taper is designed according to the viscosity of each material. The smaller the taper, the less material adheres to the flow channel, thereby reducing carbonization and reducing the risk of yellowing and blackening. The viscosity and other characteristics of each material are different, so different angles are required to adapt to different raw materials.

[0012] In one embodiment of the first aspect, 2 to 20 discharge slots are evenly arranged on the conical outer wall head of the laminating head. The number of discharge slots is also determined according to the fluidity of the plastic raw material and the degree of wear of the screw head and the check ring. For example, when producing PC (polycarbonate) with a high viscosity, the melt index is 8g / 10min. At this time, the number of slots should be increased or the slots should be widened to ensure that the plastic can flow smoothly.

[0013] In one embodiment of the first aspect, the screw head is fixedly connected to the screw rod via a thread, and the screw teeth matched between the screw head and the screw rod, and the screw teeth matched between the internal threaded portion and the external threaded portion are opposite to the rotation direction of the screw rod. This arrangement ensures that when the screw rod is working, the rubber head and the screw head will not loosen, and the screw head and the screw rod will not loosen, thereby avoiding a gap between the two due to looseness, thereby affecting product quality.

[0014] In one implementation of the first aspect, the diameter of the screw head is 14 to 300 mm, and the length of the screw head is 30 to 500 mm.

[0015] In one embodiment of the first aspect, the surfaces of the coating head, the check ring and the screw head are subjected to coating treatment, and the coating treatment includes one of PVD vacuum coating CRN, TIN, TD, electroplating, QPQ, DLC or CROMA. Through the coating treatment, the surface of the screw head assembly is smoother, more wear-resistant, and more corrosion-resistant, and less likely to adhere to plastic.

[0016] In a second aspect, the present application also provides a method for installing the seamless screw head assembly as described above, the installation method comprising the following steps:

[0017] (1) Installing the screw head on one end of the screw until the top end of the screw fits with the tail end of the meson;

[0018] (2) The check ring is sleeved on the screw head;

[0019] (3) The glue head is heated and rotated, and the external threaded portion of the screw head is screwed into the internal threaded portion of the glue head until it is tightened, so that the sealing guide of the glue head expands and is inserted into the front guide of the screw head. After the glue head cools down, the installation is completed.

[0020] In one embodiment of the second aspect, in step (3), the heating temperature is 120-400°C. At this temperature, a shrink-fitting of the rubber head and the screw head can be achieved. At the same time, since this temperature is higher than the temperature of the material during injection molding, during injection molding, although the rubber head will expand slightly at the working temperature, it cannot make the inner diameter of the rubber head sealing guide larger than the outer diameter of the front guide, thereby ensuring that the rubber head sealing guide and the front guide always maintain an interference fit during injection molding, isolating the air between the external threaded portion and the internal threaded portion.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] (1) It can eliminate the gap generated when the ordinary screw head is installed into the screw and fits with the meson, and at the same time isolate the gap between the rubber head and the screw head from the outside world, thereby preventing the air in the gap from overflowing during the production process, which would cause the air to continuously decompose and flow into the product;

[0023] (2) Solve the problem that the screw head needs to be replaced as a whole after it is worn. Different materials of glue heads can be installed to suit different working conditions, and replacement is convenient and quick;

[0024] (3) Simple structure, low processing difficulty and lower cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the structure of the seamless screw head assembly of the present application;

[0026] Figure 2 It is a schematic diagram of the main structure of the screw head;

[0027] Figure 3 It is a left view structural schematic diagram of the screw head;

[0028] Figure 4 This is a schematic diagram of the main structure of the laminating head;

[0029] Figure 5 The left side structural diagram of the laminating head;

[0030] Figure 6 This is a schematic diagram of the main structure of the stop reverse ring;

[0031] Figure 7 This is a schematic diagram of the left-side structure of the stop reverse ring.

[0032] In the accompanying drawings, 1 is a glue head, 11 is an internal threaded portion, 12 is a glue head sealing guide, 13 is a conical head, 14 is a wrench position, 15 is a discharge trough, 2 is a stop ring, 21 is a seal angle of the stop ring, 22 is a glue passage, 3 is a screw head, 31 is a meson, 32 is an external threaded portion, 33 is a front guide, 34 is a rear guide, 35 is a rear thread, 36 is a front hexagonal wrench position, 37 is a rear hexagonal wrench position, 38 is a seal angle of the meson, and 39 is a glue portion. DETAILED DESCRIPTION

[0033] Unless otherwise indicated, implied from the context, or customary in the prior art, all parts and percentages in this application are based on weight, and the test and characterization methods used are all current as of the filing date of this application. Where applicable, the contents of any patent, patent application or publication referred to in this application are fully incorporated herein by reference, and their equivalent patent families are also incorporated by reference, especially the definitions of synthesis techniques, product and processing designs, polymers, comonomers, initiators or catalysts disclosed in these documents in the art. If the definition of a specific term disclosed in the prior art is inconsistent with any definition provided in this application, the definition of the term provided in this application shall prevail.

[0034] The numerical ranges in this application are approximate, and therefore may include values ​​outside the range unless otherwise specified. The numerical range includes all values ​​from the lower limit to the upper limit in increments of 1 unit, provided that there is an interval of at least 2 units between any lower value and any higher value. For ranges containing single digits less than 10 (e.g., 1 to 5), 1 unit is generally considered to be 0.1. These are only specific examples of what is intended to be expressed, and all possible combinations of values ​​between the lowest and highest values ​​listed are considered to be clearly recorded in this application.

[0035] The terms "comprise", "include", "have" and their derivatives do not exclude the presence of any other components, steps or processes, and have nothing to do with whether these other components, steps or processes are disclosed in this application. In contrast, the term "consisting essentially of excludes any other components, steps or processes from the scope of any subsequent description of the term, except those necessary for operational performance. The term "consisting of" does not include any components, steps or processes that are not specifically described or listed. Unless explicitly stated, the term "or" refers to the listed members alone or in any combination.

[0036] Example

[0037] The embodiments of the present invention will be described in detail below. This embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation method and a specific operation process are given, but the protection scope of the present invention is not limited to the following embodiments.

[0038] Example 1

[0039] A seamless screw head assembly, the structure of which is as follows Figure 1 As shown, it is mainly composed of a glue head 1, a check ring 2, and a screw head 3.

[0040] The structure of the screw head 3 is as follows Figure 2 , Figure 3 As shown, from left to right are the front hexagon wrench position 36, the external threaded portion 32, the front guide 33, the glue portion 39, the meson 31, the rear screw thread 35 and the rear hexagon wrench position 37. The right end of the screw head 3 is fixedly connected to the screw through the rear screw thread 35 (the screw is not shown in the figure, and the screw axis is provided with an internal thread matching the rear screw thread). The screw thread at the connection between the rear screw thread 35 and the screw is a left thread, and the external threaded portion 32 is a left thread. This is because the rotation mode of the screw is right rotation (positive rotation), and the screw threads at both ends of the screw head 3 adopt a reverse thread structure, which can prevent loosening. The screw head 3 and the glue head 1 will become tighter and tighter as they rotate, avoiding loosening and gaps. However, there are also a small number of European injection molding machine screws that are reversed, so when the screw is reversed, the screw head must be designed as a positive thread to prevent loosening. The front hexagon wrench position 36 and the rear hexagon wrench position 37 are used to disassemble and install the screw head 3. A meson 31 is integrally formed in the middle of the screw head 3. The left end face of the meson 31 is tapered to form a meson sealing angle 38. The right end of the meson 31 is a rear guide 34, which fits the left end of the screw and is used for guiding and positioning when the screw head 3 is installed with the screw. The front guide 33 is used for guiding and positioning when the screw head 3 is installed with the glue head 1.

[0041] The structure of the glue head 1 is as follows Figure 4 , Figure 5As shown, the outer wall of the glue head 1 includes a conical head 13 and a wrench position 14. The middle inner hole of the glue head 1 and the rightmost end of the wrench position 14 of the glue head 1 have a small step, so that the glue head 1 can better cooperate with the screw head. In the inner hole, an internal threaded portion 11 and a glue head sealing guide 12 are arranged from left to right, and a guide matching the front guide 33 is arranged on the glue head sealing guide 12. Among them, the external threaded portion 32 and the internal threaded portion 11 match each other, the glue head sealing guide 12 is sleeved on the outside of the front guide 33, and the front guide 33 and the glue head sealing guide 12 are interference fit by heat sleeve, and the guides of the two are also interference fit. In this embodiment, the angle of the conical head 13 is 30°, and four discharge grooves 15 are arranged on the conical head 13. In this embodiment, the thread teeth of the internal threaded portion 11 of the glue head 1 and the external threaded portion 32 of the screw head 3 are both left-handed to prevent falling during rotation. The outer diameter, length and inner hole tolerance of the check ring are all within the normal standard range. The outer diameter of the rubber head 1 is smaller than the outer diameter of the check ring 2. In this embodiment, the diameter of the screw head 3 is 50 mm, and the length of the screw head 3 is 100 mm.

[0042] The structure of the check ring is as follows: Figure 6 , Figure 7 As shown, the check ring 2 is a hollow annular structure, which is sleeved outside the glue passing part 39 of the screw head 3, and the inner wall of the check ring 2 and the outer wall of the glue passing part 39 form a glue passing channel 22. At the right end of the check ring 2, a check ring sealing angle 21 with a conical surface is formed. The check ring sealing angle 21 is the same as the meson sealing angle 38, which plays the role of fine sealing. The check ring sealing angle 21 and the meson sealing angle 38 have specifications such as 90°, 15°, and 30°, mainly 90° and 15°.

[0043] During installation, first install the screw head 3 in the thread of the screw, and tighten it with a wrench on the front hexagonal wrench position 36 at the left end of the screw head 3; then insert the check ring 2 into the screw head 3, and finally heat the rubber head 1 to 150°C, so that the rubber head 1 expands slightly, just making the inner diameter of the rubber head sealing guide 12 slightly larger than the outer diameter of the front guide 33, so that the rubber head sealing guide 12 can be sleeved outside the front guide 33, and then quickly sleeve the rubber head 1 on the screw head 3 and tighten it to complete the installation. After the rubber head 1 cools down, the rubber head 1 shrinks, and the front guide 33 and the rubber head sealing guide 12 have an interference fit.

[0044] The above description of the embodiments is to facilitate those of ordinary skill in the art to understand and apply the present application. It is obvious that those familiar with the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without having to pay creative labor. Therefore, the present application is not limited to the embodiments herein, and improvements and modifications made by those skilled in the art based on the contents disclosed in the present application without departing from the scope and spirit of the present application are within the scope of the present application.

Claims

1. A seamless screw head assembly, the screw head assembly is fixed at one end of the screw, the screw head assembly comprises a screw head, a meson, a non-return ring and a glue head, the meson is fixed to the screw head, the glue head is sleeved at one end of the screw head, the non-return ring is sleeved on the screw head and is located between the glue head and the meson, characterized in that: One end of the screw head is provided with an external threaded portion and a front guide in sequence, and the middle part of the gluing head is provided with an internal threaded portion and a gluing head sealing guide, wherein the external threaded portion and the internal threaded portion match each other, the gluing head sealing guide sleeve is arranged on the outside of the front guide, and the front guide and the gluing head sealing guide are interference fit by shrink sleeve.

2. The seamless screw head assembly according to claim 1, characterized in that: The meson is coaxially arranged on the screw head.

3. The seamless screw head assembly according to claim 1, characterized in that: The head of the outer wall of the glue-passing head is conical, and the tail of the outer wall is a wrench position.

4. The seamless screw head assembly according to claim 3, characterized in that: The angle of the tapered outer wall head of the laminating head is 10-120°.

5. The seamless screw head assembly according to claim 3, characterized in that: 2 to 20 discharge slots are evenly arranged on the conical outer wall head of the laminating head.

6. The seamless screw head assembly according to claim 1, characterized in that: The screw head is fixedly connected to the screw rod via a thread, and the thread teeth matching between the screw head and the screw rod, and the thread teeth matching between the internal thread part and the external thread part are all opposite to the rotation direction of the screw rod.

7. The seamless screw head assembly according to claim 1, characterized in that: The diameter of the screw head is 14-300 mm, and the length of the screw head is 30-500 mm.

8. The seamless screw head assembly according to any one of claims 1 to 7, characterized in that: The surfaces of the coating head, the check ring and the screw head are subjected to coating treatment, wherein the coating treatment includes one of PVD vacuum coating CRN, TIN, TD, electroplating, QPQ, DLC or CROMA.

9. A method for installing a seamless screw head assembly as claimed in any one of claims 1 to 8, characterized in that: The installation method comprises the following steps: (1) Install the screw head on one end of the screw until the top end of the screw fits with the tail end of the meson; (2) Sleeve the check ring onto the screw head; (3) Heat the glue head and rotate the glue head. Screw the external thread portion of the screw head into the internal thread portion of the glue head until it is tightened. Finally, the sealing guide of the glue head expands and is inserted into the front guide of the screw head. After the glue head cools down, the installation is completed.

10. The method for installing a seamless screw head assembly according to claim 9, characterized in that: In step (3), the heating temperature is 120-400°C.

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