CN108327179B - Nitrogen nozzle assembly used in gas-assisted mold - Google Patents

Abstract

The invention provides a nitrogen nozzle assembly used in a gas-assisted mold. The gas-assisted mold is provided with an insert for accommodating the nitrogen nozzle assembly, the nitrogen nozzle assembly is arranged in the insert, and includes: a gas needle The core sleeve is embedded in the installation part of the insert, the wall surface enclosed by the outer surface is matched with the inner wall surface of the installation part, and the inside of the gas needle core sleeve defines an accommodating space; and the gas needle core is fixed in the accommodating space , and has a gas channel connecting the air channel and the flow channel, the air channel is used to introduce gas from the outside, and the flow channel is the flow channel after the gas enters the cavity in the gas-assisted mold; and the gas channel has an inlet connecting the air channel. The gas end is connected to the gas outlet end of the flow channel, and the gas needle core on the gas outlet end side exceeds the first predetermined length of the surface where the insert is located on the gas outlet end side. The invention ensures the tightness of the nitrogen nozzle in the working process, facilitates its disassembly, installation and maintenance on the gas-assisted mold, and ensures that the sealing ring therein is not damaged.

Description

A nitrogen nozzle assembly used in a gas-assisted mold

technical field

The invention relates to the technical field of gas-assisted molding, in particular to a nitrogen nozzle assembly used in a gas-assisted mold.

Background technique

Gas-assisted molding has more and more application trends recently. Gas-assisted molding (GIM) refers to the injection of high-pressure inert gas when the plastic is properly filled into the cavity (90% to 99%), and the gas pushes the molten plastic to continue to fill the cavity, and the gas pressure is used instead of the plastic. An emerging injection molding technology. The mold commonly used in gas-assisted molding is a gas-assisted mold. In the gas-assisted molding process, the gas has two functions: one is to drive the flow of plastic to continue to fill the mold cavity; the other is to form a hollow pipe, reduce the amount of plastic used, reduce the weight of the finished product, shorten the cooling time and transmit the holding pressure more effectively . Generally, the nitrogen nozzle assembly is used as the main device for air intake in gas-assisted molding. Therefore, the structure and performance of the nitrogen nozzle assembly as the gas inlet device in the gas-assisted molding process directly affect the final quality of the gas-assisted molding.

The nitrogen nozzles in the prior art are generally installed by means of threaded fastening, which may have problems such as insufficient machining accuracy of the holes and insufficient verticality of the threads during tapping, and then cause air leakage after the nitrogen nozzles are installed. . What's more, the nitrogen nozzle in the prior art may not be installed or stuck after installation during the installation process, which is inconvenient for the replacement and maintenance of the nitrogen nozzle in the later stage. Moreover, when the nitrogen gas nozzle is installed in the prior art, the sealing ring on the nitrogen gas nozzle is always broken, which cannot make it actually function in the subsequent use process.

SUMMARY OF THE INVENTION

One object of the present invention is to provide a nitrogen nozzle assembly used in a gas-assisted mold, which ensures the tightness of the nitrogen nozzle during the working process and avoids any occurrence of air leakage.

A further object of the present invention is to enable the nitrogen nozzle to be easily disassembled, installed and maintained on the gas-assisted mold, and to ensure that the sealing ring is not damaged during the installation process.

In particular, the present invention provides a nitrogen nozzle assembly used in a gas-assisted mold, the gas-assisted mold is provided with an insert for accommodating the nitrogen nozzle assembly, and the nitrogen nozzle assembly is disposed in In the insert, it includes: a gas needle core sleeve, which is embedded in the mounting part of the insert, the wall surface enclosed by the outer surface is matched with the inner wall surface of the mounting part, and the gas needle core The inside of the sleeve defines an accommodating space; and the gas needle core is fixed in the accommodating space and has a gas channel communicating with the air channel and the flow channel, the air channel is used for introducing gas from the outside, and the flow channel is a flow channel after the gas enters the cavity in the gas-assisted mold; and the gas channel has an inlet end connected to the air channel and an air outlet end connected to the flow channel, and the gas needle core is at the gas outlet The side of the end exceeds the first predetermined length of the surface of the insert on the side of the gas outlet.

Further, the gas-assisted mold has a separable fixed mold and a movable mold, the fixed mold is provided with the air channel, the movable mold is provided with the flow channel, and the insert is a fixed mold insert, The fixed mold insert is fixed in the fixed mold, and the gas needle core, the gas needle core sleeve, and the fixed mold insert seal and fit the fixed mold on the side of the air inlet end, so as to Leakage of gas from the air passage into the gas passage is prevented.

Further, the gas-assisted mold has a separable fixed mold and a movable mold, the fixed mold is provided with the flow channel, the movable mold is provided with the air channel, and the insert is a movable mold insert, The movable mold insert is fixed in the movable mold, and the gas needle core, the gas needle core sleeve, and the movable mold insert are sealed and fit the movable mold on the side of the air inlet end, so as to Leakage of gas from the air passage into the gas passage is prevented.

Further, the nitrogen nozzle assembly further includes: a sealing ring arranged on one side of the intake end, and the sealing ring is arranged between the gas needle core sleeve and the fixed mold, so that the sealing ring is The ring can seal the gap between the gas needle core sleeve and the fixed die, so as to prevent gas from overflowing from the gap when entering the gas channel from the air channel.

Further, the gas needle core sleeve has a sealing groove arranged around the circumference of the gas channel on one side of the gas inlet end, and the sealing ring is arranged in the sealing groove.

Further, the gas needle core sleeve on the side of the gas outlet end exceeds the surface of the insert on the side of the gas outlet end by a second predetermined length.

Further, the first predetermined length is greater than the second predetermined length.

Further, the wall surface enclosed by the outer surface of the gas needle core sleeve has a taper on the side close to the gas outlet end, so that the gas needle core sleeve seals the port of the installation portion on the gas outlet end side. , so as to prevent the molten plastic from overflowing from the gap between the mounting portion and the gas needle core sleeve.

Further, the cross-sectional area of the gas channel at the gas inlet end is larger than the cross-sectional area of the gas outlet end, so as to control the flow rate and flow of the gas when it leaves the gas channel and enters the flow channel.

Further, the first predetermined length is 1.5mm˜2mm.

The nitrogen nozzle assembly used in the gas-assisted mold of the present invention is due to the tight combination between the nitrogen nozzle and the insert, as well as the tight structural design and specific positional relationship between the nitrogen nozzle, the fixed die insert and the sealing ring, so It can avoid the occurrence of gas leakage during the working process of the nitrogen nozzle to the greatest extent. Because the nitrogen nozzle is installed on the fixed mold insert, the sealing ring of the nitrogen nozzle is compressively arranged between the gas needle core sleeve and the fixed mold to fill the space between the gas needle core sleeve and the fixed mold clearance, so as to meet the sealing requirements between components.

Further, the nitrogen gas nozzle of the present invention is first installed on the fixed mold insert, and then the assembly is fixed on the fixed mold, so as to ensure that the sealing ring is not damaged during the installation process. Moreover, such an installation method can facilitate the disassembly, installation and maintenance of the nitrogen nozzle on the gas-assisted mold.

The above and other objects, advantages and features of the present invention will be more apparent to those skilled in the art from the following detailed description of the specific embodiments of the present invention in conjunction with the accompanying drawings.

Description of drawings

Hereinafter, some specific embodiments of the present invention will be described in detail by way of example and not limitation with reference to the accompanying drawings. The same reference numbers in the figures designate the same or similar parts or parts. It will be understood by those skilled in the art that the drawings are not necessarily to scale. In the attached picture:

1 is a schematic assembly diagram of a nitrogen nozzle assembly used in gas-assisted molding according to an embodiment of the present invention;

Fig. 2 is a partial enlarged view of the assembly schematic diagram of the nitrogen nozzle assembly shown in Fig. 1;

Fig. 3 is a detailed view of the gas needle core cover shown in Fig. 1, wherein the front view, cross-sectional view and top view of the gas needle core cover are shown;

4 is a detailed view of the gas needle core shown in FIG. 1, wherein the front view, cross-sectional view, top view and bottom view of the gas needle core are shown;

FIG. 5 is a disassembled perspective view of the gas needle core, the gas needle core sleeve and the sealing ring shown in FIG. 1 .

The meanings of the symbols in the figure are:

1. Moving die, 2. Flow channel, 3. Nitrogen nozzle, 31. Gas needle core, 32, Gas needle core sleeve, 33, Seal ring, 4. Fixed die insert, 5. Screw, 6. Air channel, 7 , Fixed mold, 81, first end, 82, second end, 83, sealing groove, 91, inlet end, 92, outlet end.

Detailed ways

As shown in FIG. 1 and FIG. 5 , the nitrogen nozzle 3 of the present invention is mainly composed of a gas needle core 31 , a gas needle core sleeve 32 and a sealing ring 33 . FIG. 3 shows the inner and outer structure of the gas needle core sleeve 32 in detail. FIG. 4 shows the inner and outer structures of the gas needle core 31 in detail. The structure of the nitrogen gas nozzle will be described in detail below with reference to FIGS. 3 , 4 and 5 .

As shown in FIG. 3 , the gas needle core sleeve 32 is in the shape of a long cylinder, wherein the wall surface surrounded by the outer surface of the gas needle core sleeve 32 is a shape formed by combining a plurality of cylinders with different diameters. At the first end 81 of the gas needle core sleeve 32, the wall surface enclosed by the outer surface thereof is a first cylindrical shape, which has a first diameter and a first length extending along the central axis. At the second end 82 of the gas needle core sleeve 32, the wall surface enclosed by the outer surface thereof is a second cylindrical shape, which has a second diameter and a second length extending along the central axis. The combination of the first cylindrical shape and the second cylindrical shape, the central axes of the two are the same central axis, wherein the first diameter is larger than the second diameter, and the first length is smaller than the second length. The wall surface surrounded by the outer surface of the gas needle core sleeve 32 has a certain taper at the second end 82 . On the other hand, the gas needle core sleeve 32 is provided at the first end 81 with a sealing groove 83 circumferentially disposed around the inner wall surface of the first cylindrical first end 81 . Therefore, the wall surface enclosed by the outer surface of the gas needle core sleeve 32 is finally roughly "T" shaped. The gas needle core sleeve 32 defines an accommodating space inside.

As shown in FIG. 4 , the gas needle core 31 is fixed in the accommodating space. In order to better fix the gas needle core 31 in the accommodating space, the wall surface enclosed by the outer surface of the gas needle core 31 cooperates with the inner wall surface of the gas needle core sleeve 32 to be tightly fixed. The gas needle core 31 also has two ends, which are an air inlet end 91 and an air outlet end 92 respectively. The air inlet end 91 corresponds to the first end 81 , and the air outlet end 92 corresponds to the second end 82 . Between the gas inlet end 91 and the gas outlet end 92 is a through passage of the gas needle core 31 , that is, a gas passage, so that the gas can flow smoothly from the gas inlet end 91 in the gas passage to the gas outlet 92 . The cross-sectional area of the gas passage at the inlet end 91 is larger than the cross-sectional area at the outlet end 92 . This facilitates control of the flow rate and flow of gas as it exits the gas channel. In this embodiment, the cross-sectional area of the gas channel at the gas outlet end 92 is drastically reduced. Since the flow rate of the gas is related to the change of the channel section through which it flows, the gas can obtain a faster flow rate after passing through the gas channel with a sharply reduced cross-section.

As shown in FIG. 5 , the gas channel formed by the gas inlet end 91 and the gas outlet end 92 is arranged on the side of the wall surface surrounded by the outer surface of the gas needle core 31 . The sealing ring 33 is arranged on one side of the air inlet end 91 , and the sealing ring 33 is arranged in the sealing groove 83 of the gas needle core sleeve 32 .

As shown in FIG. 1 and FIG. 2 , the nitrogen nozzle 3 composed of the gas needle core 31 , the gas needle core sleeve 32 and the sealing ring 33 is installed in the fixed die insert 4 . The stationary mold insert 4 has a mounting portion capable of nesting the gas needle core sleeve 32 . The wall surface enclosed by the outer surface of the gas needle core sleeve 32 is matched with the inner wall surface of the mounting portion. In particular, the wall surface enclosed by the outer surface of the gas needle core sleeve 32 has a taper on the side of the second end 82, that is, the side close to the gas outlet end 92, and the taper can make the gas The needle core sleeve 32 seals the mounting portion on one side of the gas outlet end 92 to prevent molten plastic from overflowing from the gap between the mounting portion and the gas needle core sleeve 32 during operation. In one embodiment, the taper of the gas needle core sleeve 32 at the second end 82 is matched with the taper of the fixed die insert 4 on the same side, in order to prevent the fitting clearance between the gas needle core sleeve 32 and the taper of the fixed die insert 4 If it is too large, the fitting clearance between the taper of the gas needle core sleeve 32 and the fixed die insert 4 is generally set to be 0.01-0.02 mm. Optionally, the fitting clearance between the taper of the gas needle core sleeve 32 and the fixed die insert 4 may be 0.015 mm. Optionally, the fitting clearance between the taper of the gas needle core sleeve 32 and the fixed die insert 4 may also be 0.01 mm. Optionally, the fitting clearance between the taper of the gas needle core sleeve 32 and the fixed die insert 4 may also be 0.02 mm.

In other embodiments, the nitrogen nozzle 3 composed of the gas needle core 31 , the gas needle core sleeve 32 and the sealing ring 33 can also be installed in the movable mold insert. The movable mold insert is fixed in the movable mold 1 . Moreover, correspondingly, the stationary mold 7 is provided with the flow channel 2 , and the movable mold 1 is provided with the air channel 6 for introducing gas from the outside. The gas needle core 31 , the gas needle core sleeve 32 and the movable mold insert are sealed against the movable mold 1 on the side of the air inlet 91 to prevent the gas from entering the air passage 6 . leaks when the gas passage is described.

Further, the gas-assisted mold has a separable fixed mold 7 and a movable mold 1 . The fixed mold 7 and the movable mold 1 are the upper and lower parts of the mold, respectively, which can be parted at the set position. The stationary mold 7 is provided with an air passage 6 for introducing gas from the outside. The fixed mold insert 4 is fixed in the fixed mold 7 , and the gas needle core 31 , the gas needle core sleeve 32 and the fixed mold insert 4 are sealed on the side of the air inlet 91 . The fixed mold 7 is fitted to avoid leakage of gas when entering the gas channel from the air channel 6 . In this embodiment, the fixed mold insert 4 is fixed to the fixed mold 7 by a plurality of screws or screws 5 . After the nitrogen gas nozzle 3 is fixed to the fixed mold insert 4, the sealing ring 33 of the nitrogen gas nozzle 3 is arranged between the gas needle core sleeve 32 and the fixed mold 7, so that the sealing ring 33 can be The gap between the gas needle core sleeve 32 and the fixed die 7 is sealed to prevent gas from overflowing from the gap when entering the gas channel from the air channel 6 .

Further, the movable mold 1 is provided with a flow channel 2, and the flow channel 2 is a flow channel after the gas enters the cavity in the gas-assisted mold. The fixed fixed mold insert 4 is attached to the movable mold 1 on the side of the gas outlet 92 . Wherein, the gas needle core 31 on the side of the gas outlet end 92 exceeds the surface of the fixed die insert 4 on the side of the gas outlet end 92 by a first predetermined length. In this embodiment, the first predetermined length is 1.5 mm˜2 mm. The designer of the present application further found through analysis of the gas flow rate in the gas needle core 31 and the flow channel 2 that when the first predetermined length exceeds 2 mm, the length of the gas needle core 31 will break through the flow of the cavity of the gas-assisted mold. Channel 2, so that the gas cannot fully enter the flow channel 2, but the gas will leak in the flow channel 2, thereby affecting the molding of the product; on the contrary, when the first predetermined length is less than 1.5mm, the length of the gas needle core 31 is too small. The power of the gas to enter the flow channel 2 initially is insufficient, which in turn affects the molding of the product by the gas in the flow channel 2 . Therefore, the designer of the present application found that when the first predetermined length is in the range of 1.5mm to 2mm, the gas can completely enter the flow channel 2 with a suitable initial power, and then the product can be well formed in the flow channel 2 . That is to say, the first predetermined length may be 1.5mm, 1.6mm, 1.8mm, 2mm and other values. The gas needle core sleeve 32 on the side of the gas outlet end 92 exceeds the surface of the fixed die insert 4 on the side of the gas outlet end 92 by a second predetermined length. The first predetermined length is greater than the second predetermined length, that is, the length of the gas needle core 31 extending into the flow channel 2 is greater than the length of the gas needle core sleeve 32 extending into the flow channel 2 . Therefore, the gas can smoothly enter the flow channel 2 through the gas needle core 31 instead of flowing back into the gas needle core sleeve 32 .

The nitrogen gas nozzle assembly is arranged in the fixed die insert 4 , in particular, the nitrogen gas nozzle assembly includes a nitrogen gas nozzle 3 . The gas needle core 31 in the nitrogen nozzle 3 has a gas channel connecting the gas channel 6 and the flow channel 2, so that the external air enters the gas needle core 31 through the air channel 6 of the fixed die 7, and then passes through the gas channel of the gas needle core 31. Enter the flow channel 2 of the movable mold 1 to push the molten plastic in the flow channel 2 to a predetermined position, thereby obtaining a hollow cast plastic product.

Further, the installation steps of the nitrogen gas nozzle 3 will be described in detail with reference to FIGS. 1 to 5 . First, the gas needle core 31 , the gas needle core sleeve 32 and the sealing ring 33 are assembled to form the nitrogen gas nozzle 3 . Then, the nitrogen gas nozzle 3 is installed in the stationary mold insert 4 . Next, the stationary mold insert 4 is fastened to the stationary mold 7 with the screws 5 . The gap between the nitrogen gas nozzle 3 and the air passage 6 of the stationary die 7 is sealed with a sealing ring 33 . This fixing method avoids the high damage rate of the sealing ring 33 during the installation process. The installed nitrogen nozzle 3 has its inlet end 91 butted against the air channel 6 , and its outlet end 92 extends into a part of the first predetermined length into the flow channel 2 . Since the gas-assisted mold covers the nitrogen nozzle 3 with molten plastic during the intake process, the gas will not leak on the runner 2, which will cause the product to be unstable during production.

Further, both the gas needle core sleeve 32 and the gas needle core 31 have their special processing precision requirements. In the cooperation between the gas needle core sleeve 32 and the gas needle core 31, in order to achieve a better cooperation during use, the dimensional accuracy of the two planes of the gas needle core 31 requires key control, especially in the parts with tolerances. within the tolerance range.

By now, those skilled in the art will recognize that, although various exemplary embodiments of the present invention have been illustrated and described in detail herein, the present invention may still be implemented in accordance with the present disclosure without departing from the spirit and scope of the present invention. The content directly determines or derives many other variations or modifications consistent with the principles of the invention. Accordingly, the scope of the present invention should be understood and deemed to cover all such other variations or modifications.

Claims (8)

1. A nitrogen gas nozzle assembly for use in a gas-assisted mold, the gas-assisted mold having therein an insert for housing the nitrogen gas nozzle assembly, the nitrogen gas nozzle assembly disposed in the insert and comprising:

the gas needle core sleeve is embedded in the mounting part of the insert, the wall surface surrounded by the outer surface of the gas needle core sleeve is matched with the inner wall surface of the mounting part, and a containing space is limited in the gas needle core sleeve; and

the gas needle core is fixed in the accommodating space, the wall surface surrounded by the outer surface of the gas needle core is matched with the inner wall surface of the gas needle core sleeve to be tightly fixed, the gas needle core is provided with a gas channel communicated with a gas channel and a flow channel, the gas channel is used for introducing gas from the outside, and the flow channel is a flow channel after the gas enters a cavity in the gas-assisted mold; and is

The gas channel is provided with a gas inlet end connected with the gas channel and a gas outlet end connected with the flow channel, and the gas needle core exceeds the surface of the insert on one side of the gas outlet end by a first preset length;

the gas needle core is sleeved on one side of the gas outlet end and exceeds the surface of the insert on one side of the gas outlet end by a second preset length, wherein the first preset length is larger than the second preset length.

2. The nitrogen nozzle assembly as claimed in claim 1, wherein the gas-assisted mold has a fixed mold and a movable mold which are separable, the fixed mold is provided with the gas passage, the movable mold is provided with the flow passage, wherein the insert is a fixed mold insert fixed in the fixed mold, and the gas needle core, the gas needle core sleeve and the fixed mold insert are in sealing fit with the fixed mold on the side of the gas inlet end so as to prevent gas from leaking from the gas passage into the gas passage.

3. The nitrogen nozzle assembly as claimed in claim 1, wherein the gas-assisted mold has a fixed mold and a movable mold which are separable, the fixed mold is provided with the flow passage, the movable mold is provided with the gas passage, wherein the insert is a movable mold insert fixed in the movable mold, and the gas needle core, the gas needle core sleeve and the movable mold insert are hermetically attached to the movable mold on the side of the gas inlet end to prevent gas from leaking from the gas passage into the gas passage.

4. The nitrogen nozzle assembly as recited in claim 2, further comprising:

the sealing ring is arranged on one side of the air inlet end and arranged between the air needle core sleeve and the fixed die, so that the sealing ring can seal a gap between the air needle core sleeve and the fixed die to prevent gas from entering the gas channel from overflowing from the gap.

5. The nitrogen nozzle assembly as claimed in claim 4, wherein said gas needle hub has a seal groove around a circumference of said gas channel on a side of said gas inlet end, said seal ring being disposed in said seal groove.

6. The nitrogen nozzle assembly of any one of claims 1-5, wherein a wall bounded by an outer surface of the air spike sheath is tapered on a side adjacent the air exit end such that the air spike sheath seals a port of the mounting portion on the air exit end side to prevent molten plastic from escaping from a gap between the mounting portion and the air spike sheath.

7. The nitrogen nozzle assembly of any of claims 1-5, wherein the cross-sectional area of the gas channel at the gas inlet end is larger than the cross-sectional area thereof at the gas outlet end to control the flow rate and flow of gas as it exits the gas channel into the flow passage.

8. The nitrogen nozzle assembly as recited in claim 1, wherein the first predetermined length is between 1.5mm and 2 mm.

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