A screw

Abstract

The present application relates to injection molding production technical field, specifically disclose a kind of screw, with screw rib and flow channel, the flow channel has several protrusions, and the groove is formed between adjacent two protrusions;On the arbitrary section perpendicular to the spiral direction of the flow channel, the protrusion forms first circular arc, the groove forms second circular arc, the first circular arc is tangent to adjacent second circular arc, and the circle corresponding to all the first circular arc and the circle corresponding to the second circular arc are tangent to the curve formed by the section;The surface of the flow channel of the present application is changed in length direction every section, to form uneven surface, to improve the mixing and melting effect of screw, avoid material blockage groove, solve the problem that finished product appears black dot.

Description

Technical Field

[0001] This invention relates to the field of injection molding production technology, and in particular to a screw. Background Technology

[0002] Screw extrusion mechanisms are commonly used due to their advantages such as simple structure, convenient operation and maintenance, and ability to establish stable extrusion pressure. The screw is a crucial component of an extruder, typically employing a single or twin screw. The application of screws is gradually expanding to include filling, blending, and reactive extrusion of various materials, placing higher demands on melt mixing efficiency. Currently commonly used types include pin screws, corrugated screws, cavitation transfer mixers, and separator screws.

[0003] Current screws have varying degrees of poor adaptability to different material systems and screw speeds, lack an adaptive mechanism for the melting process, and may even cause material blockage in the screw channel, resulting in problems such as black spots on the finished product.

[0004] Therefore, existing technologies still need to be improved and developed. Summary of the Invention

[0005] The purpose of this invention is to address the difficulties of enhanced melting and poor adaptability to blending of multiple materials by providing a screw that solves the problem of material blockage in the screw channel, which leads to black spots on the finished product, in conventional screws of the prior art.

[0006] A screw having helical screw ridges and flow channels formed between two adjacent screw ridges, the flow channels having a plurality of protrusions extending along the helical direction of the flow channels, and a groove being formed between two adjacent protrusions;

[0007] On any cross section perpendicular to the spiral direction of the flow channel, the protrusion forms a first arc, the groove forms a second arc, the first arc is tangent to the adjacent second arc, and all circles corresponding to the first arc and the second arc are tangent to the curve formed by the cross section.

[0008] The curve is: y=Asin(ωx+φ)+k, where A is the height of the spiral edge, k, ω, φ∈R and ω≠0.

[0009] Specifically, the center of the circle of the screw in any cross section is set as (x0, y0), and this center is defined as the origin of the coordinates of the curve, that is: (x0, y0) = (0, 0);

[0010] The curve satisfies the following condition: k is the radius of the screw.

[0011] Specifically, the flow channel has a first cross section perpendicular to the spiral direction, and the curve formed by the first cross section satisfies the following conditions: ω=1 / 2L, φ=-π / 8L, where L is the width of the flow channel, and -0.5L≤x≤0.5L.

[0012] Specifically, the flow channel has a second cross section perpendicular to the spiral direction, and the curve formed by the second cross section satisfies the following conditions: ω=1 / 2L, φ=-3π / 8L, where L is the width of the flow channel, and -0.5L≤x≤0.5L.

[0013] Specifically, the flow channel has a third cross section perpendicular to the spiral direction, and the curve formed by the third cross section satisfies the following conditions: ω=1 / L, φ=-π / 2L, where L is the width of the flow channel, and -0.5L≤x≤0.5L.

[0014] The beneficial effects of this invention are:

[0015] This invention discloses a screw in which an arbitrary curve is used as a reference within the flow channel, and the curve continuously changes along the length of the flow channel. A curve is formed at the upper end of each cross-section, and this curve is tangent to the circles formed by protrusions and grooves. Furthermore, the circle formed by each protrusion is tangent to the circle formed by the adjacent groove. The number of protrusions and grooves, and the size of the circles formed, can follow a certain pattern or be irregular, but the tangency principle must be maintained to ensure smooth flow without dead angles. This allows the flow channel surface to vary at each cross-section along its length, creating an uneven surface. This improves the mixing and melting effect of the screw, prevents material from clogging the grooves, and solves the problem of black spots appearing in the finished product. In addition, the curve variation allows for a large operational space, the unevenness effect can be controlled, and there are no dead angles, so it can be arranged on the surface of the screw at any position. Attached Figure Description

[0016] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0017] Figure 1 This is a perspective view of the screw in Example 1;

[0018] Figure 2 This is a perspective view of the spiral edge and flow channel of Example 1 after unfolding along the spiral direction;

[0019] Figure 3 This is a front view of the spiral edge and flow channel of Example 1 after unfolding along the spiral direction;

[0020] Figure 4 This is a rear view of the spiral edge and flow channel of Example 1 after they have been unfolded along the spiral direction.

[0021] Figure 5This is a schematic diagram of the structure of multiple cross sections on the flow channel in Example 1;

[0022] Figure 6 The coordinate graph of the curve formed by the first cross section of Example 1;

[0023] Figure 7 The coordinate graph of the curve formed by the second cross section of Example 1;

[0024] Figure 8 The coordinate graph of the curve formed by the third section of Example 1;

[0025] Figure 9 This is a structural schematic diagram of the third section of Example 1;

[0026] Figure 10 This is a structural schematic diagram of the seventh section of Example 2.

[0027] The attached figures are labeled as follows: screw 10; screw ridge 11; flow channel 12; protrusion 121c; groove 122c; first arc 1211c; second arc 1221c; curves 30a, 30b, 30c, 30d, 30e, 30f, 30g; first section 40a; second section 40b; third section 40c; fourth section 40d; fifth section 40e; sixth section 40f; seventh section 40g. Detailed Implementation

[0028] This invention provides a screw. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention.

[0029] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0030] Example 1

[0031] This embodiment discloses a screw; please refer to [reference needed]. Figure 1As shown, the screw 10 in this embodiment can be applied in the injection molding process as a screw unit in the injection molding machine. The radius of the screw 10 is k, k≠0, and the size of k can be adjusted according to the actual production application. The outer surface of the screw 10 has a spiral screw ridge 11 and a flow channel 12 formed between two adjacent screw ridges 11. Various plastic masterbatches are fed from the feed port of the injection molding machine and formed into molten material after being subjected to high temperature. Under the rotation of the screw 10, the molten material flows along the feed end of the flow channel 12 to the discharge end.

[0032] To improve the mixing effect of the molten material, please refer to... Figure 1 As shown, the flow channel 12 in this embodiment has a plurality of protrusions 121 extending along the spiral direction of the flow channel 12, and a groove 122 is formed between two adjacent protrusions 121. The protrusions 121 and the grooves 122 form an uneven surface. When the material passes through the uneven surface, the mixing and melting effect of the material can be improved. Because the curve change has a large operating space, the uneven effect can be controlled, and there are no dead corners. Therefore, it can be arranged on the surface of any position of the screw 10.

[0033] For ease of understanding, this embodiment simulates the unfolding of the spiral ridge 11 and flow channel 12 along the spiral direction. The three-dimensional view of the unfolded spiral ridge 11 and flow channel 12 is shown below. Figure 2 As shown, the front view of the unfolded screw thread 11 and flow channel 12 is as follows: Figure 3 As shown, the rear view of the unfolded screw thread 11 and flow channel 12 is as follows. Figure 4 As shown, through Figures 2-4 As can be seen, the protrusions 121 and the grooves 122 are irregular, wavy extension structures. When the material flows through the protrusions 121 and the grooves 122, the mixing and melting effect of the material can be improved, the material can be prevented from blocking the grooves 122, and the problem of black spots appearing in the finished product can be solved.

[0034] The surface of the flow channel 12 varies in every cross section along its length. The upper end of each cross section forms a curve that is tangent to the circle formed by the protrusion 121 and the circle formed by the groove 122. Moreover, the circle formed by each protrusion 121 is tangent to the circle formed by the adjacent groove 122. The number of protrusions 121 and grooves 122 and the size of the circles formed can follow a certain pattern or be irregular, but the tangency principle must be guaranteed. That is, each circle of the cross section is tangent to the adjacent circle and also tangent to the curve of the cross section, so as to ensure that the screw edge 11 and the flow channel 12 are smooth and unobstructed, with no dead angles throughout.

[0035] The curve mentioned above should be a sine curve, i.e., y = Asin(ωx + φ) + k, where A is the height of the screw 11, k is the radius of the screw 10, ω and φ ∈ R and ω ≠ 0; and the values ​​of ω and φ are different for each cross section to form curves with different shapes and curvatures.

[0036] It should be noted that in the above sine curve, A refers to the amplitude. When the object makes a linear reciprocating motion with a trajectory that conforms to the sine curve, its value is 1 / 2 of the stroke. In this embodiment, the amplitude is set to the height of the screw ridge 11, which can prevent the highest point of the curve from exceeding the highest point of the screw ridge 11, and maximize the fluctuation amplitude of the screw ridge 11 and the flow channel 12.

[0037] It should be noted that in the above sine curve, k is the offset, which is reflected in the coordinate system as an upward or downward shift of the image. In this embodiment, the offset is set to the radius of screw 10, but this does not mean that k for all sine curves is necessarily the radius of screw 10. The value of k is set according to the coordinate reference system. For example, if... Figure 5 If the bottom left side of the flow channel 12 is taken as the origin (0, 0), then in this case, the value of k can be set to 0. Setting the offset k as the radius of the screw 10 is to better illustrate the positional relationship between the flow channel 12 and the screw 10.

[0038] Based on the above, in this embodiment, the center of the screw 10 in any cross section is set as (x0, y0), and the center of the circle is defined as the origin of the curve, that is: (x0, y0) = (0, 0), which can better explain the positional relationship between the flow channel 12 and the screw 10. The origin of the coordinates in the following cases is based on the center of the screw 10 in any cross section as the origin of the curve.

[0039] It should be noted that this embodiment uses... Figure 2 The structure of the flow channel 12 shown is described below. The flow channel 12 has, in sequence along the material flow direction, a first cross section 40a, a fourth cross section 40d, a third cross section 40c, a second cross section 40b, a third cross section 40c, a fifth cross section 40e, a third cross section 40c, and a sixth cross section 40f, which are perpendicular to the spiral direction of the flow channel 12. The top of the first cross section 40a forms a curve 30a; the top of the second cross section 40b forms a curve 30b; the top of the third cross section 40c forms a curve 30c; the top of the fourth cross section 40d forms a curve 30d; the top of the fifth cross section 40e forms a curve 30e; and the top of the sixth cross section 40f forms a curve 30f.

[0040] Please refer to Figure 5 and 6 As shown, curve 30a is: y = Asin(1x / 2L + φ) + k, where A is the height of the screw 11, k is the radius of the screw 10, ω = 1 / 2L, φ = -π / 8L, and -0.5L ≤ x ≤ 0.5L. When x = -0.5L, y = k, meaning the starting point of curve 30a is the bottom position of the left screw 11 inside the flow channel 12; when x = 0.5L, y = k + A, meaning the ending point of curve 30a is the top position of the right screw 11 inside the flow channel 12.

[0041] Please refer to Figure 5 and 6 As shown, with the first section 40a to the fourth section 40d as the reference positive direction, the material first flows from the inlet of the flow channel 12 to the position of the first section 40a. The starting point of the curve 30a of the first section 40a is the bottom position of the left screw ridge 11 in the flow channel 12, and the ending point is the top position of the right screw ridge 11 in the flow channel 12. In the flow channel 12, the curve 30a, the screw ridge 11 and the screw 10 form an approximately triangular cross section. Inside the triangle, there are several circles formed by the protrusions 121 and the grooves 122.

[0042] Please refer to Figure 5 As shown, from the first section 40a to the fourth section 40d, compared with the curve 30a, the lowest point on the left side of the curve 30d rises and the highest point on the right side falls. At the same time, the size of the circle formed by the protrusion 121 and the groove 122 below the curve 30d also changes.

[0043] From the fourth section 40d to the third section 40c, compared to the curve 30d, the lowest point on the left side of curve 30c rises and the highest point on the right side falls. At the same time, the size of the circle formed by the protrusion 121 and the groove 122 below curve 30c also changes.

[0044] From the third section 40c to the second section 40b, compared to curve 30c, the lowest point on the left side of curve 30b rises and the highest point on the right side falls. At the same time, the size of the circle formed by the protrusion 121 and the groove 122 below curve 30b also changes.

[0045] Please refer to Figure 5 and 7 As shown, curve 30b is: y = Asin(1x / 2L + φ) + k, where A is the height of the screw 11, k is the radius of the screw 10, ω = 1 / 2L, φ = -3π / 8L, and -0.5L ≤ x ≤ 0.5L. When x = -0.5L, y = k + A, meaning the starting point of curve 30b is the top position of the left screw 11 inside the flow channel 12; when x = 0.5L, y = k, meaning the ending point of curve 30b is the bottom position of the right screw 11 inside the flow channel 12.

[0046] like Figure 9 As shown, in the third section 40c, the protrusion 121 forms the first arc 1211c, and the groove 122 forms the second arc 1221c. The first arc 1211c is tangent to the adjacent second arc 1221c. All the circles corresponding to the first arc 1211c and the circles corresponding to the second arc 1221c are tangent to the curve 30c formed by the third section 40c.

[0047] Please refer to Figure 5 and 8As shown, curve 30c is: y = Asin(1x / 2L + φ) + k, where A is the height of the screw ridge, k is the radius of screw 10, ω = 1 / L, φ = -π / 2L, and -0.5L ≤ x ≤ 0.5L. When x = -0.5L, y = k + 0.5A, meaning the starting point of curve 30c is the middle position of the left screw ridge 11 inside the flow channel 12; when x = 0, y = k + A, meaning the midpoint of curve 30c is the same height as the top of screw ridge 11 inside the flow channel 12; when x = 0.5L, y = k + 0.5A, meaning the ending point of curve 30c is the middle position of the right screw ridge 11 inside the flow channel 12.

[0048] Between the first section 40a and the second section 40b, since the curves 30a and 30b vary considerably, in order to make the protrusions 121 and the grooves 122 smoother, at least one third section 40c needs to be formed between the first section 40a and the second section 40b. The third section 40c is symmetrical from left to right. By changing the size and number of circles below the curve 30c it forms, the third section 40c can smoothly transition to any section. Moreover, when changing from any section to other sections, it can first change to the third section 40c and then change to other sections to achieve a smooth transition.

[0049] The transition from the first section 40a to the second section 40b is one possible variation, but other variations can also be used, such as... Figure 5 As shown, for example, the change from the third section 40c to the sixth section 40f is another variation. Of course, the method of changing the section is not limited to the above two, and can be adapted according to the width of the flow channel 12, the height of the screw ridge 11, etc.

[0050] Example 2

[0051] In addition, such as Figure 10 As shown, the position of the curve can also be adjusted. For example, the curve 30g can be set below the circle formed by the seventh section 40g. The curve used can be a sine curve or a cosine dashed line. The parameters can be adjusted according to the actual situation, but the tangency principle must be ensured. That is, each circle of the seventh section 40g is tangent to the adjacent circle and tangent to the curve 30g to ensure that the screw edge 11 and the flow channel 12 are smooth and unobstructed, with no dead angles throughout, while avoiding material blockage of the groove 122 and solving the problem of black spots appearing in the finished product.

[0052] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention, and these equivalent modifications or substitutions are all included within the scope defined by the claims of the present invention.

Claims

1. A screw, characterized in that, The screw has a helical spiral edge and a flow channel formed between two adjacent spiral edges. The flow channel has a plurality of protrusions extending along the spiral direction of the flow channel, and a groove is formed between two adjacent protrusions. On any cross section perpendicular to the spiral direction of the flow channel, the protrusion forms a first arc, the groove forms a second arc, the first arc is tangent to the adjacent second arc, and all circles corresponding to the first arc and the second arc are tangent to the curve formed by the cross section. The curve is: y=Asin(ωx+φ)+k, where A is the height of the spiral edge, k, ω, φ∈R and ω≠0; Let the center of the circle of the screw in any cross section be (x0, y0), and define the center of the circle as the origin of the coordinates of the curve, that is: (x0, y0) = (0, 0); The curve satisfies the following condition: k is the radius of the screw.

2. A screw according to claim 1, characterized in that, The flow channel has a first cross section perpendicular to the spiral direction, and the curve formed by the first cross section satisfies the following conditions: ω=1 / 2L, φ=-π / 8L, where L is the width of the flow channel, and -0.5L≤x≤0.5L.

3. A screw according to claim 1, characterized in that, The flow channel has a second cross section perpendicular to the spiral direction, and the curve formed by the second cross section satisfies the following conditions: ω=1 / 2L, φ=-3π / 8L, where L is the width of the flow channel, and -0.5L≤x≤0.5L.

4. A screw according to claim 1, characterized in that, The flow channel has a third cross section perpendicular to its spiral direction. The curve formed by the third cross section satisfies the following conditions: ω=1 / L, φ=-π / 2L, where L is the width of the flow channel, and -0.5L≤x≤0.5L.

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