CN111674009A - an extruder screw - Google Patents

Abstract

The invention provides an extruder screw, in particular to the field of extruders, comprising a screw, the cross section of the screw is oval; the screw is provided with a helical fin outside, and the center point of the helical fin is the same as the screw. The center point of the ellipse is coincident, and the diameter of the helical fin is the same as the large diameter Do of the ellipse; the ratio of the large diameter Do of the ellipse to the small diameter Di of the ellipse is 1.5 to 1.7; the screw It is a hollow structure, and the screw is provided with an internal spline, and the pressure angle of the internal spline is 25 to 35 degrees; and the screw is provided with a spline shaft matching the internal spline. The invention can improve the extrusion efficiency of the screw.

Description

an extruder screw

technical field

The invention belongs to the field of extruders, in particular to an extruder screw.

Background technique

The screw extruder relies on the pressure and shear force generated by the rotation of the screw, so that the material can be fully plasticized and uniformly mixed, and formed through the die. Plastic extruders can be basically classified into twin-screw extruders, single-screw extruders and less common multi-screw extruders and screw-free extruders. The extrusion efficiency of the existing extruder screw still needs to be further improved; in view of the deficiencies of the existing technology, an extruder screw is needed, which can improve the extrusion efficiency of the screw.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide an extruder screw, which can improve the extrusion efficiency of the screw.

The invention provides the following technical solutions:

An extruder screw, including a screw, the cross section of the screw is oval; the screw is provided with a helical fin outside, and the center point of the helical fin coincides with the center point of the ellipse, and the helical fin is The diameter of the sheet is the same as the major diameter Do of the oval; the major diameter Do is 18 to 177 mm;

The ratio of the large diameter Do of the ellipse to the small diameter Di of the ellipse is 1.5 to 1.7; the screw is a hollow structure, and the screw is provided with internal splines, and the pressure angle of the internal splines is 25 to 35 The screw is provided with a spline shaft matching the internal spline.

Preferably, the ratio of the large diameter Do of the ellipse to the small diameter Di of the ellipse is 1.55; the pressure angle of the internal spline is 30 degrees.

Preferably, the helical fin, the screw and the internal spline are integrally formed.

Preferably, the spline shaft includes an inner shaft and an outer shaft, the outer shaft is hollow inside, the outer shaft of the outer shaft matches the inner spline of the screw, and the inner shaft is arranged inside the outer shaft; The outside of the shaft is provided with a strip-shaped groove, the inner side wall of the outer shaft is provided with a strip-shaped protrusion, and the protrusion is embedded in the groove.

Preferably, there are three grooves and three protrusions each, and the protrusions are evenly arranged on the inner sidewall of the outer shaft; the grooves are evenly arranged on the outer sidewall of the inner shaft.

Preferably, both ends of the outer shaft are provided with a limiting mechanism for locking the outer shaft, and the limiting mechanism is movably connected with the inner shaft.

Preferably, the limiting mechanism includes a limiting block and a threaded rod, one end of the threaded rod is connected to the limiting block, and the other end of the threaded rod is threadedly connected to the inner shaft.

Preferably, the side of the limiting block is provided with a groove whose cross section is a regular hexagon, a regular quadrilateral or a regular triangle.

Beneficial effects of the present invention:

The cross section of the screw of the present invention is oval; the screw fin is provided outside the screw, and the center point of the helical fin is coincident with the center point of the ellipse, and the diameter of the helical fin is the same as the large diameter Do of the ellipse; The ratio of the large diameter Do and the elliptical small diameter Di is 1.5 to 1.7; the screw is a hollow structure, and there are internal splines in the screw, and the pressure angle of the internal splines is 25 to 35 degrees; The spline shaft with matching key can ensure the maximum diameter-to-volume ratio and torque of screw extrusion by controlling the ratio of the large diameter Do and the small diameter Di of the screw, and the pressure angle, thereby improving the extrusion efficiency and ensuring the internal spline. Strength of.

Description of drawings

The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of the specification, and are used to explain the present invention together with the embodiments of the present invention, and do not constitute a limitation to the present invention. In the attached image:

Fig. 1 is the axial view of the present invention;

Fig. 2 is the front view of the present invention;

3 is a sectional view of the present invention;

Figure 4 is a structural diagram of a spline shaft;

Marked as: 1, screw; 2, spiral fin; 3, internal spline; 4, spline shaft; 41, inner shaft; 42, outer shaft; 5, limit mechanism; 51, limit block; 52 , threaded rod.

Detailed ways

1 to 4, an extruder screw includes a screw 1, and the cross section of the screw 1 is elliptical; the screw 1 is provided with a helical fin 2 outside, and the center point of the helical fin 2 is the same as the The center points of the ellipse 1 are coincident, and the diameter of the helical fins 2 is the same as the large diameter Do of the ellipse; the ratio of the large diameter Do of the ellipse to the small diameter Di of the ellipse is 1.5 to 1.7 The screw 1 is a hollow structure, and the screw 1 is provided with an internal spline 3, and the pressure angle of the internal spline 3 is 25 to 35 degrees; and the screw 1 is provided with a spline matching the internal spline 3 The shaft 4 is used to drive the rotation of the screw 1 . By controlling the ratio of the large diameter Do and the small diameter Di and the pressure angle of the screw, the diameter-to-volume ratio and torque of the screw extrusion can be maximized, thereby improving the extrusion efficiency and ensuring the strength of the internal spline; the helical fins 2. The screw 1 and the internal spline 3 are integrally formed; the ratio of the large diameter Do of the ellipse to the small diameter Di of the ellipse is 1.55; the pressure angle of the internal spline 3 is 30 degrees; Selecting the screw of this size can ensure that the diameter-to-volume ratio and torque of the extruder are maximized, thereby improving the extrusion efficiency, and the internal spline of this size has high strength;

The spline shaft 4 includes an inner shaft 41 and an outer shaft 42, the outer shaft 42 is hollow inside, the outer shaft 42 is matched with the inner spline 3 of the screw 1, and the inner shaft 41 is arranged outside The inside of the shaft 42; and the outside of the inner shaft 41 is provided with a strip-shaped groove, the inner side wall of the outer shaft 42 is provided with a strip-shaped protrusion, and the protrusion is embedded in the groove to ensure the force transmission, and can ensure that the inner shaft 41 and the outer shaft 42 are firmly connected. The external teeth of the spline shaft 4 are easily damaged, and once damaged, the entire spline shaft 4 needs to be replaced, which is costly; the spline shaft 4 is set to a separate structure, and only the damaged part needs to be replaced; the groove and the There are three protrusions, and the protrusions are evenly arranged on the inner side wall of the outer shaft 42; smooth. Both ends of the outer shaft 42 are provided with a limiting mechanism 5 for locking the outer shaft 42 , the limiting mechanism 5 is movably connected with the inner shaft 41 , and the outer shaft 42 is fixed by the limiting mechanism 5 ; The limit mechanism 5 includes a limit block 51 and a threaded rod 52 , one end of the threaded rod 52 is connected to the limit block 51 , the other end of the threaded rod 52 is threadedly connected to the inner shaft 41 , and is limited by the limit block 51 . The position block can realize the threaded rod 52 and the inner shaft 41, and then the outer shaft 42 can be disassembled; the side of the limit block 51 is provided with a groove whose cross section is a regular hexagon, a regular quadrilateral or a regular triangle, which is convenient for using tools. Rotate the limit block 51 .

How the present invention works:

As shown in Figures 1 to 4, the ratio of the large diameter Do of the ellipse to the small diameter Di of the ellipse is 1.55; the pressure angle of the internal spline 3 is 30 degrees; selecting a screw of this size can ensure the extrusion The diameter-to-volume ratio and torque of the machine are maximized, which can improve the extrusion efficiency, and the internal spline of this size has high strength; the limit block 51 is rotated by using a tool, and the thread can be realized through the limit block 51. The rod 52 and the inner shaft 41, and then the outer shaft 42 can be disassembled; the outer teeth of the spline shaft 4 are easily damaged, and once damaged, the entire spline shaft 4 needs to be replaced, and the cost is relatively large; the spline shaft 4 is set to a separate structure , only need to replace the damaged part

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still describe the foregoing embodiments. modify the technical solutions, or perform equivalent replacements for some of the technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (8)

1. An extruder screw, characterized in that: the screw rod is provided with an oval cross section; the screw is externally provided with a spiral fin, the central point of the spiral fin is coincident with the central point of the ellipse, and the diameter of the spiral fin is the same as the major diameter Do of the ellipse; the major diameter Do is 18 to 177 mm;

the ratio of the major diameter Do of the ellipse to the minor diameter Di of the ellipse is 1.5 to 1.7; the screw rod is of a hollow structure, an internal spline is arranged in the screw rod, and the pressure angle of the internal spline is 25-35 degrees; and a spline shaft matched with the internal spline is arranged in the screw rod.

2. An extruder screw according to claim 1, wherein: the ratio of the major diameter Do of the ellipse to the minor diameter Di of the ellipse is 1.55; the pressure angle of the internal spline is 30 degrees.

3. An extruder screw according to claim 1, wherein: the helical fins, the screw rod and the internal spline are of an integrally formed structure.

4. An extruder screw according to claim 1, wherein: the spline shaft comprises an inner shaft and an outer shaft, the inner part of the outer shaft is hollow, the outer part of the outer shaft is matched with the inner spline of the screw, and the inner shaft is arranged in the outer shaft; and the outside of interior axle is equipped with the recess of bar, the inside wall of outer axle is equipped with the arch of bar, the arch embedding in the recess.

5. An extruder screw according to claim 4, wherein: the number of the grooves and the number of the protrusions are three respectively, and the protrusions are uniformly arranged on the inner side wall of the outer shaft in an annular mode; the grooves are uniformly arranged on the outer side wall of the inner shaft in an annular mode.

6. An extruder screw according to claim 4, wherein: and two ends of the outer shaft are provided with limiting mechanisms for locking the outer shaft, and the limiting mechanisms are movably connected with the inner shaft.

7. An extruder screw according to claim 6, wherein: the limiting mechanism comprises a limiting block and a threaded rod, one end of the threaded rod is connected with the limiting block, and the other end of the threaded rod is in threaded connection with the inner shaft.

8. An extruder screw according to claim 7, wherein: the side face of the limiting block is provided with a groove with a cross section of a regular hexagon, a regular quadrangle or a regular triangle.

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