Improved screw reverse ring mechanism for injection molding machine

Abstract

The utility model provides an improved screw reverse ring mechanism for injection molding machine, which comprises a reverse ring, an auxiliary ring and a sealing ring. The reverse ring comprises a first ring body and a second ring body. The auxiliary ring is sleeved on the second ring body. At least two first openings are axially penetrated through the reverse ring. At least two second openings are axially penetrated through the auxiliary ring. The second openings are staggered with the first openings. The reverse ring is divided into several reverse ring segments through the first openings. Each reverse ring segment is connected with the sealing ring. The staggered openings on the reverse ring and the auxiliary ring can achieve better deformation effect when the injection molding machine is working, thereby achieving very good sealing effect and finally improving the injection quality of the injection molding machine. The integrated design of the reverse ring, the auxiliary ring and the sealing ring can effectively prevent the leakage of raw materials during the working process and further affect the product quality of the injection molding.

Description

TECHNICAL FIELD

[0001] The application relates to the field of injection molding machines, in particular to an improved screw reverse ring mechanism for an injection molding machine. BACKGROUND

[0002] An injection molding machine is an indispensable machine in injection molding, which is mainly used for manufacturing various plastic products by using a plastic molding die on thermoplastic or thermosetting plastic. The screw reverse ring of the injection molding machine is one of important parts in the injection molding machine, which is mainly used for realizing the sealing effect during injection of the injection molding machine, and the sealing effect will affect the injection pressure and other factors, so the sealing effect brought by the screw reverse ring of the injection molding machine determines the performance of the injection molding machine to some extent.

[0003] The reverse ring is generally sleeved on the screw of the injection molding machine, and does the forward and backward axial movement with the screw in the barrel during work. The outer circular wall of the reverse ring is in abutment with the inner circular wall of the barrel, and the gap between the two circular walls (hereinafter referred to as the ring-cylinder gap) is sealed by the reverse ring.

[0004] In order to improve the injection performance, the ring-cylinder gap should be as small as possible in theory. However, due to the great difference in deformation of the reverse ring and the barrel caused by temperature influence, and the different working temperatures and pressures required when different materials are used to produce different products, combined with the influence of machining errors, the ring-cylinder gap will have a very large fluctuation in actual use, which is difficult to control. If the ring-cylinder gap is too small, it may become smaller under the influence of the above factors, so that the reverse ring cannot normally slide in the barrel, and both will have different degrees of wear, which greatly reduces the service life and seriously affects the product quality. If the ring-cylinder gap is too large, it may become larger under the influence of the above factors, which leads to the sealing performance not being guaranteed, thereby affecting the injection pressure, and finally seriously affecting the product quality.

[0005] The existing invention discloses a reverse ring which realizes sealing effect through deformation, such as the reverse ring with the application number "201910469528.6" and the name "screw reverse ring mechanism for injection molding machine". The reverse ring realizes deformation sealing by penetrating an opening on the reverse ring. During work, the screw moves forward to extrude the material into the reverse ring and expand outward, realizing complete sealing of the reverse ring and the barrel. When feeding, the screw rotates and moves backward, so that the raw material passes through the middle of the reverse ring and is fed into the filling area from the head of the screw to realize feeding. At this time, the reverse ring returns to its original shape without extrusion. However, the opening on the reverse ring may cause material leakage. Therefore, an auxiliary ring is added to the reverse ring to prevent material leakage. The auxiliary ring is sleeved on the reverse ring and also has an opening. The opening can realize deformation sealing with the reverse ring. The opening is not consistent with the opening on the reverse ring to prevent raw material from leaking from the gap between the openings on the reverse ring and the auxiliary ring. In order to prevent material leakage from the reverse ring during work and affect product quality, a sealing ring is added between the reverse ring and the screw gasket. When the screw moves forward during work, the material is extruded into the reverse ring and cannot leak out of the reverse ring due to the presence of the sealing ring. However, the invention still has the following shortcomings: 1) the opening on the reverse ring is only one, so the expansion effect of deformation is not good, which cannot completely match with the barrel without gap, affecting the use of the injection molding machine. 2) Because the reverse ring and the sealing ring are separated and there is no fixing structure between them, a gap will be generated between the reverse ring and the sealing ring under the action of extrusion force, and the raw material in the reverse ring will also leak out of the gap. SUMMARY

[0006] In order to overcome the above-mentioned shortcomings of the prior art, the present application provides an improved screw reverse ring mechanism for injection molding machine.

[0007] The technical scheme for solving the technical problems of the present application is as follows: an improved screw reverse ring mechanism for injection molding machine, comprising a reverse ring, an auxiliary ring and a sealing ring, wherein the reverse ring comprises a first ring body and a second ring body, the auxiliary ring is sleeved on the second ring body, at least two first openings are axially penetrated on the reverse ring, at least two second openings are axially penetrated on the auxiliary ring, the second openings are staggered with the first openings, the reverse ring is divided into several reverse ring segments through the first openings, and the several reverse ring segments are connected with the sealing ring.

[0008] Further, the inner ring of the second ring body is provided with a first annular groove, the front end of the sealing ring is provided with a first annular protrusion, and the first annular protrusion is clamped into the first annular groove.

[0009] Further, the outer ring of the second ring body is axially provided with a first circular-arc groove, and the inner ring of the auxiliary ring is axially provided with a first positioning rib, which is inserted into the first circular-arc groove.

[0010] Further, the first ring body and the second ring body are separately arranged, the inner ring of the second ring body is provided with a second annular groove, and the rear end of the first ring body is provided with a second annular protrusion, which is clamped into the second annular groove.

[0011] Further, the auxiliary ring is radially divided into a first auxiliary ring segment and a second auxiliary ring segment, the second opening is divided into a third opening penetrating through the first auxiliary ring segment and a fourth opening penetrating through the second auxiliary ring segment, and the third opening and the fourth opening are arranged in an interlaced manner.

[0012] Further, the outer ring of the second ring body is axially provided with a second positioning rib and a third positioning rib, the inner ring of the first auxiliary ring segment is provided with a second circular-arc groove, the inner ring of the second auxiliary ring segment is provided with a third circular-arc groove, the second positioning rib is inserted into the second circular-arc groove, and the third positioning rib is inserted into the third circular-arc groove.

[0013] Further, the first opening and the second opening are one of a straight line, a circular arc or a curve.

[0014] Further, the outer diameters of the first ring body, the auxiliary ring and the sealing ring are the same, the inner diameters of the second ring body and the sealing ring are the same, and the inner diameter of the sealing ring is smaller than the outer diameter of the screw gasket on the screw of the injection molding machine.

[0015] The present application has the following advantages: 1. The plurality of interlaced openings arranged on the reverse ring and the auxiliary ring can achieve a better deformation effect when the injection molding machine is working, so that the outer ring of the reverse ring is completely attached to the inner ring of the barrel when deformed, thereby achieving a very good sealing effect and finally improving the injection quality of the injection molding machine. 2. The integrated design of the reverse ring, the auxiliary ring and the sealing ring can effectively prevent the possibility of raw material leakage during work and further affect the product quality of the injection molding. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is the internal structure diagram of the injection molding machine of the present application.

[0017] Figure 2 is the exploded view of the first embodiment of the present application.

[0018] Figure 3 is the general assembly view of the first embodiment of the present application.

[0019] Figure 4 is the exploded view of the second embodiment of the present application.

[0020] Figure 5 is a structural diagram of the second ring body of embodiment two of the present application.

[0021] Figure 6 is an assembly diagram of embodiment two of the present application. DETAILED DESCRIPTION

[0022] The present application will be further described in detail below in conjunction with the drawings and specific embodiments.

[0023] Referring to Figure 1 , the working principle of the specific check ring mechanism in the injection molding machine is as follows: the check ring mechanism (including the check ring 1, the auxiliary ring 2 and the sealing ring 3) is arranged between the screw head 5 and the screw gasket 6 in the barrel 4, the screw head connecting rod 7 passes through the center through hole of the check ring 1, and the gap between the screw head connecting rod 7 and the check ring 1 is the material conveying channel 8. When the injection molding machine enters the injection state, the screw 9 moves to the left in the drawing, the check ring mechanism slides forward after being pressed by the screw 9 and the screw gasket 6, at this time, the rightmost sealing ring 3 is in close contact with the screw gasket 6 to form a seal, and the pressure in the material conveying channel 8 continuously increases during the forward movement of the screw 9 and the check ring mechanism, so that the injection material at the front end of the check ring 1 in the barrel 2 is extruded into the material conveying channel 8, and finally the check ring 1 and the auxiliary ring 2 are extruded radially outward, the check ring 1 and the auxiliary ring 2 are elastically deformed to expand the outer diameter, so that the barrel gap 10 reaches complete sealing, ensuring the sealing effect and shortening the response time. When the injection is completed, the check ring 1 and the auxiliary ring 2 shrink and reset as the pressure decreases, the barrel gap 10 returns to its original state, and the overall check ring mechanism smoothly slides to the right with the screw 8 to return to the original position.

[0024] Embodiment one

[0025] Referring to Figure 2 and Figure 3 , an improved screw check ring mechanism for an injection molding machine, including a check ring 1, an auxiliary ring 2 and a sealing ring 3, the check ring 1 includes a first ring body 11 and a second ring body 12, and the first ring body 11 and the second ring body 12 in this embodiment are integrally formed, the auxiliary ring 2 is sleeved on the second ring body 12, four first openings 13 are axially penetrated through the check ring 1, four second openings 14 are axially penetrated through the auxiliary ring 2, and the second openings 14 are staggered with the first openings 13. The first openings 13 and the second openings 14 can make the check ring 1 and the auxiliary ring 2 produce outward expansion deformation during the use of the injection molding machine to realize the close cooperation with the barrel 10, ensuring the injection effect and product quality. Of course, the number of the first openings 13 and the second openings 14 is not limited, and it can also be two, three, five, etc. Relatively speaking, the more the number of openings, the better the deformation effect, but the cost will certainly increase, and the specific optimal use effect of the number of openings is different when corresponding to different injection molding machines and injection molding materials.

[0026] Of course, the shape of the first opening 13 and the second opening 14 is not limited, which can be straight line, circular arc, curve and irregular shape, as long as it can be deformed.

[0027] Considering that in the barrel 4, and the reverse ring 1 and the auxiliary ring 2 and the barrel gap 10 of the barrel 4 is basically set at about 0.1mm when not working, if the first opening 13 has no support, after setting two or more first openings 13, the reverse ring 1 will be divided into multiple reverse ring segments by multiple first openings 13 and appear to be split, so the multiple reverse ring segments are connected with the sealing ring 3, and as preferred, the first annular groove 15 in the inner circle of the second ring body 12 and the first annular protrusion 16 at the front end of the sealing ring are matched to achieve mutual connection and fixation, so through the above structure design, through very small barrel gap 10, the fixation and deformation of the reverse ring 1 divided into multiple pieces by the first opening 13 can be ensured. At the same time, in order to prevent the second opening 14 from rotating and splitting, the first positioning rib 17 is arranged on the inner circle of the auxiliary ring 2 in the axial direction, and the first circular groove 18 is arranged on the outer circle of the second ring body 12 in the axial direction, through the cooperation of the first positioning rib 17 and the first circular groove 18, one of the auxiliary ring 2 divided by the second opening 14 is fixed with the reverse ring 1, which ensures the fixation and deformation of the auxiliary ring 2.

[0028] Before being put into the injection molding machine, the setting of two or more first openings 13 and second openings 14 will make the reverse ring 1 and the auxiliary ring 2 split and not easy to assemble, so before being put in, a connecting port with appropriate thickness can be reserved on the first opening 13 and the second opening 14 to prevent the reverse ring 1 and the auxiliary ring 2 from being split, which is convenient for the assembly of the whole reverse ring mechanism, and after being put in, through the internal bulging deformation movement, the connecting port will be broken, thereby forming the first opening 13 and the second opening 14 which are completely penetrated. Of course, the openings at the first opening 13 and the second opening 14 can also be temporarily bonded by glue or other methods, and then split after being put into the injection molding machine for work.

[0029] In designing the reverse ring mechanism, the open leakage and other gap leakage must be considered, because the leakage will directly affect the quality of the product. Therefore, in this embodiment, the leakage inside the reverse ring mechanism is considered first, the first opening 13 and the second opening 14 are staggered, and the outer diameters of the first ring body 12, the auxiliary ring 2 and the sealing ring 3 are the same. When the injection molding machine is working, the first ring body 12 and the auxiliary ring 2 are inflated to make the ring cylinder gap 10 completely sealed and not leak. The extruded raw material flows into the first opening 13 and is blocked by the auxiliary ring 2, so there is no leakage through the above design. Considering the gap between the inside of the barrel and the reverse ring, the inner diameters of the second ring body 12 and the sealing ring 3 are the same, and the inner diameters of the second ring body 12 and the sealing ring 3 are smaller than the outer diameter of the screw gasket 6 on the screw of the injection molding machine. Because the screw 9 moves forward when the injection molding machine is working, the reverse ring mechanism slides forward together with the screw 9 and the screw gasket 6 after being pushed by the screw 9 and the screw gasket 6. At this time, the rightmost sealing ring 3 is in contact with the screw gasket 6, and the above design ensures that the sealing ring 3 and the screw gasket 6 will not have a gap when they are matched, so as to prevent leakage and ensure the sealing effect of the sealing ring 3 and the screw gasket 6.

[0030] Embodiment two

[0031] Referring to Figure 4 , Figure 5 and Figure 6 , considering that the screw head 5 will rotate back when it is reset, the screw head 5 may be stuck on the first opening 13 and rotate the reverse ring mechanism together, which is not in working condition. When not in working condition, the reverse ring 1 and the auxiliary ring 2 are in free state and do not have internal inflation deformation, so they will slightly drop under the influence of gravity in the horizontal injection molding machine. Therefore, when the screw head 5 rotates the reverse ring 1 and the auxiliary ring 2, the outer circle of the reverse ring 1 and the auxiliary ring 2 will rub against the inner wall of the barrel 4, thereby accelerating the wear of the inner wall of the barrel 4 and the reverse ring 1 and the auxiliary ring 2, thereby greatly reducing the service life and sealing effect of the reverse ring mechanism and the barrel 4.

[0032] Considering the above problems, in this embodiment, the first ring body 11 and the second ring body 12 are separated and connected through the connecting structure on the basis of embodiment one. The first opening 13 is arranged on the second ring body 12, and the first ring body 11 is not arranged, so that the problem of the screw head 5 being stuck on the first ring body 11 when rotating is avoided. As a preferred embodiment, the second ring-shaped groove 19 on the inner circle of the second ring body 12 and the second ring-shaped protrusion 20 at the rear end of the first ring body 11 are matched and fixed.

[0033] However, the first ring body 11 without the first opening 13 will not deform when the inner expansion deformation is performed, and the non-deformation of the first ring body 11 will result in that the outer diameter of the first ring body 11 is smaller than the outer diameter of the auxiliary ring 2, and at this time, the injection material will have the possibility of material leakage from the second opening 14 of the auxiliary ring 2.

[0034] In order to avoid this situation, the auxiliary ring 2 is divided into a first auxiliary ring segment 21 and a second auxiliary ring segment 22 on the basis of the first embodiment, the second opening 14 is divided to form a third opening 23 penetrating through the first auxiliary ring segment 21 and a fourth opening 24 penetrating through the second auxiliary ring segment 22, and the third opening 23 and the fourth opening 24 are staggered. After being arranged in this way, the injection material will be blocked by the second auxiliary ring segment 22 after entering the third opening 23, thereby avoiding the possibility of material leakage.

[0035] In the embodiment, the outer circle of the second ring body 12 is axially provided with a second positioning rib 25 and a third positioning rib 26, the inner circle of the first auxiliary ring segment 21 is provided with a second circular arc groove 27, the inner circle of the second auxiliary ring segment 22 is provided with a third circular arc groove 28, the second positioning rib 25 is inserted into the second circular arc groove 27, and the third positioning rib 26 is inserted into the third circular arc groove 28. Thus, the above arrangement realizes the fixed connection of the first auxiliary ring segment 21 and the second auxiliary ring segment 22 on the backstop ring 1.

[0036] And the backstop ring 1 and the auxiliary ring 2 are divided into several parts in the second embodiment, which is more convenient to replace, so that when one of the parts is damaged, the whole large part does not need to be replaced, which is relatively more cost-saving.

[0037] The embodiment is only one of the more preferred schemes of the patent, and any change made without departing from the scope of the technical scheme is within the scope of the patent.

Claims

1. An improved non-return ring mechanism for a screw of an injection molding machine, characterized by: The reverse stop ring, the auxiliary ring and the sealing ring, the reverse stop ring comprises a first ring body and a second ring body, the auxiliary ring is sleeved on the second ring body, the first ring body and the second ring body are separately arranged, the second ring body has at least two first openings from one side end face to the other side end face along the axial direction, and the first ring body is not provided with the first opening;The auxiliary ring has at least two second openings from one side end face to the other side end face along the axial direction, and the second openings are staggered with the first openings;The auxiliary ring is divided into a first auxiliary ring segment and a second auxiliary ring segment, the second openings are divided into a third opening through the first auxiliary ring segment and a fourth opening through the second auxiliary ring segment, and the third opening and the fourth opening are staggered;The second ring body is divided into a plurality of reverse stop ring segments through the first opening;The inner circle of the second ring body is provided with a second annular groove, the rear end of the first ring body is provided with a second annular protrusion, and the second annular protrusion is clamped into the second annular groove.

2. The improved non-return ring mechanism for injection molding screw of claim 1, wherein: The inner circle of the second ring body is provided with a first annular groove, the front end of the sealing ring is provided with a first annular protrusion, and the first annular protrusion is clamped into the first annular groove.

3. The improved non-return ring mechanism for injection molding screw of claim 2, wherein: The outer circle of the second ring body is axially provided with a first circular arc groove, and the inner circle of the auxiliary ring is axially provided with a first positioning rib, and the first positioning rib is inserted into the first circular arc groove.

4. The improved non-return ring mechanism for injection molding screw of claim 2, wherein: The outer circle of the second ring body is axially provided with a second positioning rib and a third positioning rib, the inner circle of the first auxiliary ring segment is provided with a second circular arc groove, the inner circle of the second auxiliary ring segment is provided with a third circular arc groove, the second positioning rib is inserted into the second circular arc groove, and the third positioning rib is inserted into the third circular arc groove.

5. The improved non-return ring mechanism for injection molding screw as claimed in any one of claims 1 to 4, characterized in that: The first opening and the second opening are one of a straight line, a circular arc or a curve.

6. The improved non-return ring mechanism for injection molding screw as claimed in any one of claims 1 to 4, characterized in that: The outer diameters of the first ring body, the auxiliary ring and the sealing ring are the same, the inner diameters of the second ring body and the sealing ring are the same, and the inner diameter of the sealing ring is smaller than the outer diameter of the screw gasket on the screw of the injection molding machine.

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