Color mixing screw head assembly of injection molding machine and injection molding screw

Abstract

The utility model relates to the field of injection molding machines, and discloses an injection molding machine color mixing screw head assembly and an injection molding screw, the injection molding machine color mixing screw head assembly comprises a screw head, a thrust ring fixedly sleeved on a connecting rod of the screw head, and a non-return ring sleeved on the connecting rod and capable of moving between the head of the screw head and the thrust ring, and an overflowing distance for guiding the molten plastic into the discharging groove exists between the non-return ring and the connecting rod, a plurality of stirring protrusions are arranged on the outer ring wall of the thrust ring at intervals in a protruding mode, and the screw head assembly can improve the color mixing efficiency.

Description

Technical Field

[0001] This utility model relates to the field of injection molding machines, and in particular to a color mixing screw head assembly and injection screw for an injection molding machine. Background Technology

[0002] Injection screws generally consist of a screw body and a screw head assembly. A typical screw head assembly consists of three parts, which can be referred to as follows: Figure 1 As shown, the assembly includes a screw head, a check ring, and a thrust ring in sequence. The screw head includes a head with its tip facing the nozzle and a connecting rod with a diameter smaller than the maximum diameter of the head. The check ring is slidably fitted onto the connecting rod, and the thrust ring is fixedly fitted onto the connecting rod. The check ring can slide between the head and the thrust ring. A flow gap is provided between the check ring and the connecting rod to allow material to pass through. A discharge trough is provided on the head to allow molten plastic passing through the flow gap to be discharged. When the check ring moves to abut against the thrust ring, it restricts the molten plastic from entering the flow gap, that is, it restricts the molten plastic from entering the discharge trough. When the check ring moves to abut against the head, the molten plastic can pass through the flow gap and enter the discharge trough.

[0003] While conveying materials, the existing screw has a certain color mixing function. However, different products have different color mixing requirements. If the color mixing requirements are increased, the existing screw can only increase the back pressure by adjusting the back pressure function on the injection molding machine. Although this method can improve the color mixing efficiency, it will prolong the color mixing time and reduce the production efficiency, which obviously does not meet the market demand. Therefore, it is necessary to improve the color mixing efficiency of the injection molding screw without reducing the production efficiency. Utility Model Content

[0004] In view of the shortcomings of existing injection molding screws in terms of color mixing efficiency, the primary objective of this utility model is to provide an injection molding machine color mixing screw head assembly that improves color mixing efficiency.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0006] A color mixing screw head assembly for an injection molding machine includes a screw head, a thrust ring fixedly sleeved on a connecting rod of the screw head, and a check ring sleeved on the connecting rod and movable between the head of the screw head and the thrust ring. The outer ring wall of the thrust ring is provided with a plurality of stirring protrusions at intervals.

[0007] By adopting the above solution, stirring protrusions are added to the outer ring wall of the thrust ring. When the thrust ring rotates with the screw body, these stirring protrusions can increase the contact area with the molten plastic, increase the stirring efficiency of the molten plastic, and accelerate the mixing. Therefore, compared with the existing screw head assembly, this screw head assembly can improve the mixing efficiency.

[0008] Preferably, the stirring protrusions are evenly spaced along the circumference of the thrust ring.

[0009] With the above scheme, after the stirring protrusions are evenly spaced circumferentially, molten plastic can pass evenly between adjacent stirring protrusions and the stirring efficiency is good.

[0010] Preferably, one or more sets of stirring protrusions are arranged along the axial direction of the thrust ring.

[0011] Preferably, two adjacent sets of stirring protrusions are set in a one-to-one correspondence or staggered arrangement.

[0012] Preferably, the stirring protrusions are vertically or obliquely protruding on the outer ring wall of the thrust ring.

[0013] Preferably, the stirring protrusions are columnar, frustum-shaped, or pyramidal.

[0014] Preferably, the cross-section of the stirring protrusion is circular, elliptical, racetrack-shaped, semi-circular, or polygonal.

[0015] Preferably, the cross-section of the stirring protrusion is square or rhomboid.

[0016] By adopting the above scheme, the above-mentioned settings for the stirring protrusions can all increase the stirring efficiency.

[0017] Preferably, the check ring has a protruding guide block that is inserted into the discharge trough, and there is a discharge gap between the guide block and the bottom of the discharge trough.

[0018] With the above scheme, the check ring rotates synchronously with the screw head, resulting in higher injection accuracy compared to a scheme where the check ring does not rotate synchronously with the screw head.

[0019] The second objective of this utility model is to provide an injection molding screw, including a screw body, wherein the end of the screw body is fixedly inserted with the aforementioned injection molding machine color mixing screw head assembly.

[0020] This utility model has significant technical effects due to the adoption of the above technical solutions: stirring protrusions are added to the outer ring wall of the thrust ring. When the thrust ring rotates with the screw body, these stirring protrusions can increase the contact area with the molten plastic, increase the stirring efficiency of the molten plastic, and accelerate the mixing. Therefore, the screw head assembly and the injection screw equipped with the screw head assembly can improve the mixing efficiency. Attached Figure Description

[0021] Figure 1 This is an isometric drawing of a screw head assembly based on existing technology;

[0022] Figure 2 This is an isometric view of a color mixing screw head assembly for an injection molding machine according to Embodiment 1;

[0023] Figure 3 This is a front view of a color mixing screw head assembly for an injection molding machine according to Embodiment 1;

[0024] Figure 4 yes Figure 3 A sectional view of AA;

[0025] Figure 5 This is an isometric view of a color mixing screw head assembly for an injection molding machine according to Embodiment 2;

[0026] Figure 6 This is a front view of the injection screw in Example 2.

[0027] The parts referred to by the numbers in the above attached figures are as follows: 1. Screw head; 101. Head; 1011. Discharge trough; 102. Connecting rod; 2. Check ring; 201. Guide block; 3. Thrust ring; 301. Stirring protrusion; 4. Flow gap; 5. Screw body; 6. Discharge gap. Detailed Implementation

[0028] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0029] Example 1

[0030] An injection molding screw, as shown in the reference Figures 2-4 As shown, the injection molding machine includes a screw body 5 and a color mixing screw head assembly fixedly installed at one end of the screw body 5. The color mixing screw head assembly includes a screw head 1, which includes a head 101 and a connecting rod 102 for insertion and fixing with the screw body 5. A thrust ring 3 is sleeved and fixed on the connecting rod 102, and a check ring 2 is sleeved on the connecting rod 102 between the head 101 and the thrust ring 3. The end of the screw body 5 is recessed with a slot for interference insertion of the end of the connecting rod 102 away from the head 101.

[0031] Three sets of discharge grooves 1011 are evenly spaced around the outer ring wall of the head 101. There is a flow gap 4 between the check ring 2 and the connecting rod 102 to guide the molten plastic into the discharge grooves 1011. Several stirring protrusions 301 are spaced on the outer ring wall of the thrust ring 3. Three sets of stirring protrusions 301 are spaced along the axial direction of the thrust ring 3, and each set has several protrusions evenly spaced around the circumference of the thrust ring 3. Two adjacent sets of stirring protrusions 301 are arranged one-to-one. The stirring protrusions 301 are perpendicular to the outer ring wall of the thrust ring 3. The stirring protrusions 301 are frustum-shaped and have a square cross-section.

[0032] A stirring protrusion 301 is added to the outer ring wall of the thrust ring 3. When the thrust ring 3 rotates with the screw body 5, these stirring protrusions 301 can increase the contact area with the molten plastic, increase the stirring efficiency of the molten plastic, and accelerate the mixing. Therefore, the injection screw equipped with the color mixing screw head assembly of the injection molding machine can improve the color mixing efficiency.

[0033] Example 2

[0034] Combination Figures 5-6 As shown, in this embodiment, based on embodiment 1, a guide block 201 is provided on the check ring 2 along its axial direction to be inserted into the discharge groove 1011. There is a discharge gap 6 between the guide block 201 and the bottom of the discharge groove 1011.

[0035] The guide block 201 drives the check ring 2 and the screw head 1 to rotate synchronously at all times. Compared with Example 1, the injection accuracy is higher. Of course, the requirements for the assembly accuracy between the injection screw and the barrel are also higher.

[0036] The above description is merely a preferred embodiment of this utility model. The protection scope of this utility model is not limited to the above embodiments. All technical solutions falling within the scope of this utility model's concept are protected. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of this utility model should also be considered within the protection scope of this utility model.

Claims

1. A color mixing screw head assembly of an injection molding machine, comprising a screw head (1), a thrust ring (3) fixedly sleeved on a connecting rod (102) of the screw head (1), and a non-return ring (2) sleeved on the connecting rod (102) and movable between a head portion (101) of the screw head (1) and the thrust ring (3), characterized in that: A plurality of stirring protrusions (301) are protruded on the outer wall of the thrust ring (3) at intervals.

2. A color-mixing screw head assembly for an injection molding machine as defined in claim 1, wherein: The stirring protrusions (301) are evenly spaced along the circumference of the thrust ring (3).

3. A color-mixing screw head assembly for an injection molding machine as defined in claim 2, wherein: The stirring protrusions (301) are arranged in one group or two or more groups at intervals along the axial direction of the thrust ring (3).

4. A color-mixing screw head assembly for an injection molding machine as defined in claim 3, wherein: The two adjacent groups of stirring protrusions (301) are arranged one by one or staggered.

5. A color-mixing screw head assembly for an injection molding machine as defined in claim 2 or 3 or 4, characterized in that: The stirring protrusions (301) are vertically or obliquely protruded on the outer wall of the thrust ring (3).

6. A color-mixing screw head assembly for an injection molding machine as defined in claim 5, wherein: The stirring protrusions (301) are columnar, frustum-shaped or prismatic.

7. A color-mixing screw head assembly for an injection molding machine as defined in claim 6, wherein: The cross section of the stirring protrusions (301) is circular, oval, track-shaped, semicircular or polygonal.

8. A color-mixing screw head assembly for an injection molding machine as defined in claim 7, wherein: The cross section of the stirring protrusions (301) is square or diamond-shaped.

9. A color-mixing screw head assembly for an injection molding machine as defined in claim 1, wherein: A guide block (201) is protruded on the reverse ring (2) and is guided and inserted into the discharge groove (1011), and the guide block (201) and the bottom of the discharge groove (1011) have a discharge gap (6).

10. An injection molding screw comprising a screw body (5), characterized in that: The end of the screw body (5) is fixedly inserted with the injection molding machine color mixing screw head assembly as claimed in any one of claims 1-9.

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