CN212045772U

CN212045772U - Hot runner valve needle system of anti melt disturbance of moulding plastics

Info

Publication number: CN212045772U
Application number: CN202020118221.XU
Authority: CN
Inventors: 张�浩
Original assignee: Shenyang Jinbei Yanfeng Automotive Interior System Co Ltd
Current assignee: Shenyang Jinbei Yanfeng Automotive Interior System Co Ltd
Priority date: 2020-01-19
Filing date: 2020-01-19
Publication date: 2020-12-01
Anticipated expiration: 2030-01-19

Abstract

A hot runner valve needle system resisting disturbance of injection molding melt belongs to the technical field of injection molding of automobile parts and overcomes the problem that the valve needle in the prior art cannot accurately enter a discharge port of a liner at the front end of a melt nozzle due to the disturbance of the injection molding melt in an injection molding melt channel to cause mutual damage of the valve needle and the discharge port of the liner, so that the surface of an injection molding product generates a flash defect and the use function of the injection molding product is influenced, the hot runner valve needle system is characterized in that an encircling positioning sleeve is arranged on the upper surface of the liner at the front end of a cylinder of the injection molding melt nozzle, the lower end of the valve needle penetrates through the encircling positioning sleeve to be matched with the discharge port of the liner at the front end of the cylinder of the injection molding melt nozzle, the double guiding positioning of the upper end positioning sleeve and the encircling positioning sleeve of the valve needle can be ensured all the time in the injection molding production process, so that the valve, the industrial requirements of mass and high-quality production of automobile injection molding parts are met.

Description

Hot runner valve needle system of anti melt disturbance of moulding plastics

Technical Field

The utility model belongs to the technical field of automobile parts injection moulding, in particular to hot runner needle system who is applied to an anti melt disturbance of moulding plastics among the automobile parts injection moulding mould.

Background

With the technical development of injection molding products and the improvement of the quality of the application field of the products, the hot runner system is widely used in the injection molding industry of automobile parts. The hot runner system has the advantages of saving injection molding particle raw materials, shortening the injection molding production period, improving the appearance quality and the mechanical property of injection molding products, simplifying the structure of the injection mold and improving the automatic production degree of the injection mold. In the hot runner system, the injection melt enters the cavity of the injection mold through the opening of the hot runner valve needle, and after the injection molding of a product is finished, the hot runner valve needle is closed to finish the production of an injection molding product, so that the batch production is finished repeatedly. In the whole injection molding production process, the stability of the hot runner valve needle in the injection molding melt is a key factor influencing the appearance quality state and the product performance of an injection molding product.

The utility model with the application number of CN201220226702.8 discloses a hot runner valve needle system, which comprises a nozzle body, a nozzle head fixed at the bottom of the nozzle body and a valve needle passing through the nozzle body and the nozzle head simultaneously, wherein a channel is longitudinally arranged in the nozzle body, a first positioning hole with the inner diameter larger than that of the channel is formed at the bottom of the channel, and a threaded hole is formed at the bottom of the first positioning hole; a first positioning column is formed at the top of the nozzle head, a locking column with external threads is formed at the bottom of the first positioning column, a through hole is longitudinally formed in the nozzle head, and a nozzle head guide hole is formed in the through hole in the middle of the nozzle head in the vertical direction; the valve needle comprises a valve rod and a valve needle guide column formed at the bottom of the valve rod; the mouth head penetrates into the channel from the bottom of the mouth body, and the first positioning column is inserted into the first positioning hole; the locking column is accommodated in the threaded hole, and the nozzle head and the nozzle body are mutually fixed through the matching of the external thread on the locking column and the threaded hole; the valve needle penetrates into the channel from the top of the nozzle body, and the valve needle guide column is inserted into the nozzle head guide hole. The hot runner valve needle system described by the utility model is a typical universal structure, the utility model realizes the precise assembly between the nozzle head and the nozzle body through the precise matching of the first positioning column and the first positioning hole, and ensures the coaxiality between the two; the precision assembly between the valve needle and the nozzle head is realized through the precision fit between the valve needle guide column and the nozzle head guide hole, and finally the precision assembly between the nozzle body, the nozzle head and the valve needle is realized; and the cooperation between screw hole and the external screw thread has then strengthened chewing the head and chewing the rigidity of being connected between the body, like this, when needle and the axis between the two of chewing the head disalignment, needle guide post and the cooperation of chewing the first guiding hole have guaranteed that needle and the axis between the head are coaxial, have avoided needle to seal the gluey post and have chewed the friction between the head, have improved the life of needle. Therefore, when the nozzle head works and meets the impact of molten glue or the impact of the valve needle on the nozzle head, the matching screw threads of the nozzle head and the nozzle body cannot be damaged, so that the interchangeability of the nozzle body and the nozzle core is enhanced, and the maintenance cost is reduced. When the hot runner system needs to close the melt adhesive, the cylinder system enables the valve needle to move downwards, and when the valve needle moves to the lower part of the nozzle head, the guide surface of the valve needle is matched with the guide surface of the nozzle head, so that the coaxiality of the sealing surface of the valve needle and the sealing surface of the nozzle head is ensured, and the collision of the end part of the valve needle and the nozzle head is avoided, and the sealing surface of the valve needle is damaged. The needle continues to move downwards, and part of the melt adhesive in the nozzle head moves upwards along the needle return trough, so that the resistance of the needle to move downwards is reduced, the acting force of the cylinder on the needle is reduced, and smooth sealing of the needle is facilitated.

However, the utility model does not describe the state in which the needle is moved upward to be opened. In fact, in the injection molding of automobile parts, as the structure of the prior art valve needle system shown in fig. 1 of the drawings of the present specification, since the diameter of the valve needle 3 is only 5mm, but the length thereof reaches 200-800 mm, the valve needle 3 is an elongated rod, as the structure diagram of the open state of the prior art valve needle shown in fig. 2 of the drawings of the present specification, when the valve needle 3 moves upward and the channel between the injection melt channel 2 and the injection product mold cavity 7 is opened, the valve needle 3 is separated from the restriction of the discharge port 4-1 of the injection melt nozzle front end bushing 4, and at this time, the valve needle 3 is disturbed by the high temperature, high pressure and high viscosity of the injection melt in the injection melt channel 2 in actual production, i.e. it is impacted by the melt, and after the injection product mold cavity 7 is filled, the valve needle 3 of the hot runner system needs to move downward, the channel between the injection molding melt channel 2 and the injection molding product mold cavity 7 is closed through the matching hole of the discharge hole of the injection molding melt nozzle front end lining 4, because the matching clearance diameter tolerance of the valve needle 3 and the discharge hole 4-1 of the injection molding melt nozzle front end lining 4 is only 0.02 mm, the valve needle 3 is impacted and disturbed by various factors of the injection molding melt in the injection molding melt channel 2, and the valve needle 3 is only restrained by the valve needle upper end positioning guide sleeve 5 arranged on the injection molding melt splitter plate 8, when the product is injection molded and the valve needle 3 is closed, the valve needle cannot accurately enter the discharge hole 4-1 of the melt nozzle front end lining 4, so that the axes of the discharge hole 4-1 of the valve needle 3 and the melt nozzle front end lining 4 are not coaxial, the valve needle 3 and the lining 4 perform relative opening and closing movement repeatedly, and mutual damage of the discharge hole 4-1 of the valve needle 3 and the lining 4 can be caused quickly, a wear gap 6 is generated between the valve needle 3 and the discharge port 4-1 of the liner 4, so that the surface of the injection molding product has flash defects, and the use function of the injection molding product is affected. According to the actual production statistics of the injection molding products of the automotive interior door panels, the flash defect generally occurs on the surfaces of the injection molding products when 200 pieces are produced. Therefore, the runner valve needle system in the prior art cannot meet the production quality requirement of mass automobile injection molding parts. In order to ensure the quality of the injection molding product and avoid the mutual abrasion of the valve needle and the front end bushing, the spare parts need to be replaced frequently.

Application number is CN 201220071910.5's utility model discloses a needle guide block for hot runner needle valve system, including the base member, be provided with the direction taper hole on the base member, with the locating hole of direction taper hole intercommunication, the cylinder body phase-match of locating hole and needle. Because the valve needle guide block adopts the structure of direction taper hole and locating hole, consequently closing the runner in-process, can realize the motion direction and the location of valve needle through the valve needle guide block to ensure that the axis of valve needle is coaxial with the axis of runner, avoid valve needle and runner wearing and tearing condition to appear, thereby effectively solve and seal the untight scheduling problem of glue, and extension valve needle life. However, as shown in fig. 3 and 4 disclosed in the drawings of the utility model, the valve needle guide block of the utility model is installed in the sprue cone, i.e. at the lower end of the discharge port of the hot nozzle, and plays a role in realizing the motion guidance and positioning of the valve needle through the valve needle guide block during the process of closing the sprue, thereby ensuring that the axis of the valve needle is coaxial with the axis of the sprue and avoiding the abrasion of the valve needle and the sprue. The utility model does not describe the state of the valve needle moving upwards to open, as shown in fig. 2 of the attached drawings of the present specification, when the valve needle 3 moves upwards and the channel between the injection melt channel 2 and the injection product mold cavity 7 is opened, the valve needle 3 is separated from the constraint of the discharge port 4-1 of the injection melt nozzle front end bushing 4, at this time, the valve needle 3 is disturbed by the high temperature, high pressure and high viscosity of the injection melt in the injection melt channel 2 in the actual production, namely, the valve needle is impacted by the molten glue, when the injection product mold cavity 7 is filled, the valve needle 3 of the hot runner system needs to move downwards and needs to pass through the matching hole of the discharge port 4-1 of the injection melt nozzle front end bushing 4 again to close the channel between the injection melt channel 2 and the injection product mold cavity 7, only before the valve needle 3 enters the discharge port 4-1 of the injection melt nozzle front end bushing 4, the valve needle guide block can realize the motion guidance and the positioning of the valve needle through the valve needle guide block only after entering the valve needle guide block, thereby avoiding the abrasion of the valve needle and a pouring gate, but the fit clearance diameter tolerance of the valve needle 3 and the positioning hole of the valve needle guide block is only 0.02 mm, the fit clearance diameter tolerance of the guide taper hole of the valve needle guide block is also very limited and is only 0.05mm, because the valve needle 3 is impacted by the injection melt and disturbed by various factors in the injection melt channel 2, the deviation degree of the valve needle 3 is far greater than the fit clearance diameter tolerance of the guide taper hole of the valve needle guide block, and the valve needle 3 is only restrained by the positioning guide sleeve 5 at the upper end of the valve needle, the valve needle 3 can not enter the valve needle guide block accurately, thereby leading the valve needle 3 to collide with the inlet of the guide taper hole of the valve needle guide block, the valve needle and the entrance of the guide taper hole of the valve needle guide block are worn mutually, and after the valve needle 3 is worn, even if the valve needle enters the positioning hole of the valve needle guide block and then is matched with the pouring gate, the sealing glue is not tight, and the service life of the valve needle system is shortened.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the problem that, overcome prior art's weak point and defect, solve the hot runner needle and receive the melt disturbance of moulding plastics, the needle can't accurate stable when closing with the accurate cooperation of bush discharge gate, can't seal the melt passageway and the injection moulding product die cavity of moulding plastics completely, cause the problem that injection moulding product can't satisfy appearance quality requirement and batch injection moulding production, the provision can be in the production process of moulding plastics, both can resist the melt disturbance of moulding plastics, can guarantee the smooth and easy flow of the melt of moulding plastics again and improve a hot runner system needle of the melt disturbance of moulding plastics of a needle life.

The technical proposal adopted by the utility model comprises an injection molding melt nozzle cylinder body and a valve needle upper end positioning sleeve, an injection molding melt channel which is longitudinally communicated is arranged in the injection molding melt nozzle cylinder body, a valve needle is arranged in the injection molding melt channel, the lower end of the injection melt nozzle cylinder is connected with an injection melt nozzle cylinder front end bushing in a threaded manner, the upper end of the valve needle passes through the valve needle upper end positioning sleeve to be connected with a piston rod of the cylinder, an encircling positioning sleeve is arranged on the upper surface of a lining at the front end of the injection molding melt nozzle cylinder body, the upper end of the encircling positioning sleeve is limited by an upper end seam allowance of an inner wall stepped positioning step of the injection molding melt nozzle cylinder body, so that the encircling positioning sleeve is locked and positioned in the injection melt channel by the lining sleeve at the front end of the injection melt nozzle cylinder body, the lower end of the valve needle penetrates through the surrounding positioning sleeve to be matched with a discharge hole of a lining at the front end of the injection molding melt nozzle barrel.

The encircling positioning sleeve comprises a cylindrical sleeve, wherein 3 positioning claws are uniformly distributed on the inner wall of the cylindrical sleeve, the two sides of the root of each positioning claw are in arc transition with the inner wall of the cylindrical sleeve respectively, the two sides of the body of each positioning claw are in arc transition with the bottom surface of each positioning claw, the front end of each positioning claw forms an elliptic encircling positioning surface, a valve needle lower end positioning guide sleeve is formed among the 3 positioning claws, and a curved streamline-shaped injection molding melt diversion channel is formed among each 2 positioning claws, the inner wall of the cylindrical sleeve and the outer wall of the valve needle lower end positioning guide sleeve.

The upper portion of needle is elongated valve rod, is equipped with the sealed valve head with the discharge gate complex of the fuse-element nozzle barrel front end bush of moulding plastics in the lower extreme of valve rod, is equipped with between the valve rod of needle and the locating pawl and embraces the clearance.

And the encircling gap between the positioning claw and the valve rod is 0.05 mm.

Compared with the prior art, the beneficial effects of the utility model reside in that:

(1) the encircling positioning sleeve with the limiting valve needle reciprocating motion position of the utility model can completely ensure that the valve needle reciprocates in the whole injection molding production process, because the valve needle is always subjected to double guiding positioning of the valve needle lower end positioning guide sleeve formed by the valve needle upper end positioning guide sleeve and the encircling positioning sleeve and limited by the stroke of the cylinder no matter the valve needle is in the opening state or the closing state, the valve needle cannot be separated from the encircling positioning sleeve, thereby make needle among the hot runner system all has abundant guiding orientation at whole motion in-process, makes the needle have sufficient rigidity to resist the fuse-element disturbance of moulding plastics, no matter open or close the cooperation precision that can guarantee the needle and the discharge gate of the fuse-element nozzle front end bush of moulding plastics, has thoroughly solved injection moulding product appearance quality problem, has satisfied the automobile and has moulded plastics the industry requirement of spare part big batch and high quality production.

(2) Embrace the melt flow channel that moulds plastics that has the curved surface streamline molding on the position sleeve, in the use, because 3 curved surface streamline molding's the melt-flow distribution box of moulding plastics, guaranteed to mould plastics the fuse-element and can be smoothly through embracing the position sleeve, do not have any influence to the smooth passing through of the fuse-element of moulding plastics, can avoid because the non-Newton fluid characteristic of the fuse-element of moulding plastics receives the structure shearing in the melt-flow channel easily and takes place the change of fuse-element viscosity to injection molding physical properties after having avoided the shaping receives the destruction. And 3 the clearance of embracing between individual positioning pawl and the valve rod can carry out the guiding orientation to the valve rod in order to guarantee, can let the valve rod reciprocate wherein smoothly again, has guaranteed the normal work of needle.

(3) The utility model provides a valve needle is easily worn and torn among the original structure of traditional hot runner system, need frequently to change the manufacturing cost including the spare part of valve needle, has improved the life of valve needle system.

Description of the drawings:

figure 1 is a schematic diagram of the structure of a prior art valve pin system,

figure 2 is a schematic view of the open state of the prior art valve needle,

figure 3 is a schematic structural diagram of the valve needle system of the present invention,

figure 4 is a structural schematic diagram of the valve needle opening state of the utility model,

figure 5 is an enlarged cross-sectional view a-a of figure 3,

figure 6 is a front view of the valve needle of the present invention encircling the positioning sleeve,

figure 7 is a cross-sectional view B-B of figure 6,

figure 8 is an axonometric view of the encircling positioning sleeve of the utility model,

fig. 9 shows the effect of the cooperation between the surrounding positioning sleeve and the needle.

In the figure:

1. an injection molding melt nozzle cylinder, 2. an injection molding melt channel,

3. the valve needle is provided with a valve needle,

3-1, valve rod, 3-2, sealing valve head,

4. a lining at the front end of the injection melt nozzle cylinder body, and a discharge hole of 4-1.

5. A positioning guide sleeve is arranged at the upper end of the valve needle, 6. an abrasion gap,

7. a mold cavity of an injection molding product, 8. an injection molding melt splitter plate,

9. the positioning sleeve is surrounded by the positioning sleeve,

9-1 parts of cylindrical sleeve, 9-2 parts of positioning claw,

9-3 parts of an injection molding melt diversion channel, 9-4 parts of a valve needle lower end positioning guide sleeve,

9-5. an elliptic encircling positioning surface,

10. encircling the gap, 11 cylinder.

Detailed Description

As shown in figures 3, 4 and 5, the utility model adopts the technical proposal that the injection molding melt splitter plate 8 is arranged in the groove at the lower surface of the injection molding melt splitter plate 8, the inner wall at the lower end of the injection molding melt nozzle barrel 1 is provided with an inner wall step type positioning step, the lower end of the inner wall step type positioning step is processed with an internal thread, an injection molding melt channel 2 which is longitudinally communicated is arranged in the injection molding melt nozzle barrel 1, the internal thread at the inner wall at the lower end of the injection molding melt nozzle barrel 1 is connected with an injection molding melt nozzle barrel front end bushing 4 in a threaded manner, the upper surface of the injection molding melt nozzle barrel front end bushing 4 is provided with an encircling positioning sleeve 9, the upper end of the encircling positioning sleeve 9 is limited by an upper end spigot of the inner wall step type positioning step of the injection molding melt nozzle barrel 1, so that the encircling positioning sleeve 9 is locked and positioned by the injection molding melt nozzle barrel front end bushing 4 in the injection molding melt channel 2, forming the basic structure of the utility model for resisting disturbance of injection molding melt; the injection molding nozzle is characterized in that a valve needle 3 is installed in an injection molding melt channel 2, the lower end of the valve needle 3 penetrates through an encircling positioning sleeve 9 to be matched with a discharge port 4-1 of a front end lining 4 of an injection molding melt nozzle barrel, the discharge port 4-1 is communicated with an injection molding product mold cavity 7, a valve needle upper end positioning sleeve 5 is installed in an upper surface groove of an injection molding melt flow distribution plate 8, and the upper end of the valve needle 3 penetrates through the valve needle upper end positioning sleeve 5 to be connected with a piston rod of an air cylinder 11.

As shown in fig. 5 to 8, the encircling positioning sleeve 9 comprises a cylindrical sleeve 9-1, 3 positioning claws 9-2 are uniformly distributed on the inner wall of the cylindrical sleeve 9-1, two sides of the root of each positioning claw 9-2 are respectively in arc transition with the inner wall of the cylindrical sleeve 9-1, two sides of the body of each positioning claw 9-2 are also in arc transition with the bottom surface of the corresponding positioning claw 9-2, so that an elliptical encircling positioning surface 9-5 is formed at the front end of each positioning claw 9-2, a valve needle lower end positioning guide sleeve 9-4 is formed among the 3 positioning claws 9-2, and an injection molding melt diversion channel 9-3 with a curved streamline is formed among each 2 positioning claws 9-2, the inner wall of the cylindrical sleeve 9-1 and the outer wall of the valve needle lower end positioning guide sleeve 9-4; an encircling gap 10 is arranged between the positioning claw 9-2 and the valve needle 3.

As shown in fig. 3, 6 and 9, the upper part of the valve needle 3 is a slender valve rod 3-1, the lower end of the valve rod 3-1 is provided with a sealing valve head 3-2 matched with a discharge port 4-1 of a front end bushing 4 of an injection molding melt nozzle cylinder, the valve rod 3-1 and the sealing valve head 3-2 are of an integral structure, an encircling gap 10 is arranged between a positioning claw 9-2 and the valve rod 3-1 of the valve needle 3, the diameter of the sealing valve head 3-2 is 5mm, the diameter of the valve rod 3-1 is 6mm, the diameter tolerance of the matching gap between the sealing valve head 3-2 and the discharge port 4-1 of the front end bushing 4 of the injection molding melt nozzle is 0.02 mm, and the encircling gaps 10 between 3 positioning claws 9-2 and the valve rod 3-1 are all 0.05 mm. In the using process, no matter the valve needle 3 is in the opening state or the closing state, the double guiding and positioning of the valve needle lower end positioning guide sleeve 9-4 formed between the valve needle upper end positioning guide sleeve 5 and the 3 positioning claws 9-2 surrounding the positioning sleeve 9 are always carried out, and the stroke of the cylinder 11 is limited, so that the valve needle 3 cannot be separated from the surrounding positioning sleeve 9, thereby leading the valve needle 3 in the hot runner system of the utility model to have sufficient guiding and positioning process in the whole movement process, leading the valve needle 3 to have enough rigidity to resist the disturbance of the injection melt, ensuring that the valve needle 3 accurately enters the discharge port 4-1 of the front end bushing 4 of the injection melt nozzle cylinder body, and because the utility model discloses 3 figurative fuse-element splitter boxes 9-3 of moulding plastics of curved surface streamline have guaranteed that the fuse-element of moulding plastics can pass through smoothly and embrace position sleeve 9, do not have any influence to the smooth passing through of the fuse-element of moulding plastics.

Claims

1. A hot runner valve needle system resisting disturbance of injection molding melt comprises an injection molding melt nozzle cylinder body (1) and a valve needle upper end positioning sleeve (5), wherein an injection molding melt channel (2) which is longitudinally communicated is arranged in the injection molding melt nozzle cylinder body (1), a valve needle (3) is arranged in the injection molding melt channel (2), the lower end of the injection molding melt nozzle cylinder body (1) is in threaded connection with an injection molding melt nozzle cylinder body front end bushing (4), the upper end of the valve needle (3) penetrates through the valve needle upper end positioning sleeve (5) to be connected with a piston rod of a cylinder (11), and the hot runner valve needle system is characterized in that an encircling positioning sleeve (9) is arranged on the upper surface of the injection molding melt nozzle cylinder body front end bushing (4), the upper end of the encircling positioning sleeve (9) is limited by an upper end spigot of an inner wall stepped positioning step of the injection molding melt nozzle cylinder body (1), so that the encircling positioning sleeve (9) is locked and positioned by the injection molding melt nozzle cylinder body front end bushing (4, the lower end of the valve needle (3) penetrates through the surrounding positioning sleeve (9) to be matched with a discharge hole (4-1) of the front end lining (4) of the injection molding melt nozzle barrel.

2. The hot runner valve needle system capable of resisting disturbance of injection molding melt according to claim 1, wherein the encircling positioning sleeve (9) comprises a cylindrical sleeve (9-1), 3 positioning claws (9-2) are uniformly distributed on the inner wall of the cylindrical sleeve (9-1), two sides of the root of each positioning claw (9-2) are respectively in arc transition with the inner wall of the cylindrical sleeve (9-1), two sides of the body of each positioning claw (9-2) are also in arc transition with the bottom surface of each positioning claw (9-2), the front end of each positioning claw (9-2) forms an elliptical encircling positioning surface (9-5), a valve needle lower end positioning guide sleeve (9-4) is formed between the 3 positioning claws (9-2), and the inner wall of the cylindrical sleeve (9-1) and the outer wall of the lower end valve needle positioning guide sleeve (9-4) to form a curved streamline between each 2 positioning claws (9-2) and the outer wall of the cylindrical sleeve (9-1) and the lower end valve needle positioning guide sleeve (9-4 A molded injection molding melt shunt groove (9-3).

3. The injection molding melt disturbance resistant hot runner valve needle system according to claim 1 or 2, wherein the upper part of the valve needle (3) is an elongated valve rod (3-1), a sealing valve head (3-2) matched with the discharge hole (4-1) of the front end bushing (4) of the injection molding melt nozzle barrel is arranged at the lower end of the valve rod (3-1), and an encircling gap (10) is arranged between the positioning claw (9-2) and the valve rod (3-1) of the valve needle (3).

4. An injection molding melt disturbance resistant hot runner valve pin system according to claim 3, wherein the embracing clearance (10) between the positioning pawl (9-2) and the valve stem (3-1) is 0.05 mm.