CN111571960A

CN111571960A - Demoulding mechanism and demoulding method of staggered-tooth snap ring plastic part forming mould

Info

Publication number: CN111571960A
Application number: CN202010416224.6A
Authority: CN
Inventors: 华明伟
Original assignee: Ningbo Zheng Jia Molding Co ltd
Current assignee: Ningbo Zheng Jia Molding Co ltd
Priority date: 2020-05-17
Filing date: 2020-05-17
Publication date: 2020-08-25

Abstract

The invention relates to a demoulding mechanism of a staggered-tooth snap ring plastic part forming die, which comprises an inclined top type sliding block sub-mechanism, an inclined top type sliding block ejection sub-mechanism and a core wane ejection sub-mechanism, wherein the inclined top type sliding block sub-mechanism comprises an inclined top type sliding block, a sliding block guide block and a sliding block insert, the sliding block guide block is fixedly arranged in a groove formed in a movable die plate through a screw, a T-shaped rib is arranged on the sliding block guide block, and the T-shaped rib is in sliding fit with a T-shaped groove formed in the inclined top type sliding block and used for guiding the upward inclined movement of the inclined top type sliding block; through ejection of the ejection plate, the four ejector rods are synchronously pushed to push the ejection ring so as to complete ejection of 12 pitched-roof type slide blocks to 24 clamping teeth on the side surface, meanwhile, the warping mechanism is driven to synchronously eject a molding core of a plastic part, the first ejection and side surface demolding actions of the plastic part are completed, and then the warping mechanism is driven to completely eject the plastic part through continuous ejection of the ejection plate so as to realize automatic demolding.

Description

Demoulding mechanism and demoulding method of staggered-tooth snap ring plastic part forming mould

Technical Field

The invention relates to the field of plastic part injection molding, in particular to a demolding mechanism and a demolding method of a staggered-tooth clamping ring plastic part molding mold.

Background

Fig. 1a and 1b show staggered tooth snap ring parts of a new ambulance adjustable seat riser, which are formed by injection molding of ABS plastic. The main body of the staggered-tooth snap ring has an outer diameter of

The total height of the conical ring is 8mm, and the average wall thickness is 2 mm; the inner wall of the conical table is smooth, 24 clamping teeth are arranged on the outer wall of the conical table, the clamping teeth are of two types with different sizes, one type is clamping teeth with the width of 3mm, the single-layer thickness of 1mm and three layers, and the clamping teeth are respectively characterized by 01-12 shown in figure 1 a. One is a single layer of latch teeth 01 'to 12' with a width of 2mm and a thickness of 1 mm. The single three-layer latch and the single-layer latch are arranged at intervals of 15 degrees of the circumference, the circumference between the three-layer latch and the three-layer latch is arranged at 30 degrees, and the radial depth of the latch is 1 mm. The mold design difficulty of the plastic part is two aspects by combining the shape characteristics of the plastic part, wherein one aspect is the pouring of the plastic part, and the other aspect is the demolding of 24 clamping teeth on the outer wall of the plastic part.

At present, in the field of injection molding, a complete set of mold demolding mechanism does not exist for efficiently completing demolding of the staggered-tooth clamping ring, so that the demolding mechanism of the staggered-tooth clamping ring plastic part molding mold is in urgent need.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provides a demoulding mechanism and a demoulding method of a staggered-tooth clamping ring plastic part forming mould.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

the utility model provides a staggered teeth snap ring moulds a forming die's demoulding mechanism, including top formula slider sub-mechanism to one side, top formula slider sub-mechanism to one side and core wane ejection sub-mechanism, top formula slider sub-mechanism to one side includes top formula slider to one side, the slider guide block, the slider mold insert, the slider guide block passes through the screw fastening and installs in the inslot that the movable mould board was seted up, be provided with T type muscle on it, the T type groove sliding fit who sets up on this T type muscle and the top formula slider to one side, be used for the ascending slant motion of top formula slider to one side to lead, the upper end of slider guide block is provided with a spacing screw and prevents to top formula slider to one side slippage from the slider guide block.

Furthermore, the ejector mechanism of the inclined ejector type sliding block comprises an annular ejector plate ring ejector ring and four push rods, the upper ends of the push rods are fixedly connected with the ejector ring through screws, the lower ends of the push rods are installed on the ejector plate, and the ejector ring is ejected upwards through the upward ejection of the ejector plate and the ejector push plate.

Further, the core wane ejector mechanism includes the kicking block, the wane pillar, the wane, wear-resisting button head, push away material mold insert spring, push away a core, the upper end disc that pushes away a core is the shaping core that the piece was moulded to the staggered teeth snap ring, the lower extreme sets up to cylindrical rod-like handle, the lower extreme suit of handle is in the direction cylinder piece, after the certain length of pushing away material mold insert spring of precompression of handle bottom suit, restrict the locking by wear-resisting button head to the spring again, the bottom surface of the cylinder groove that the movable mould backing plate corresponds to seting up is withstood to the upper end that pushes away material mold insert spring.

Further, the wear-resistant round head is made of a high-strength and wear-resistant T8A material.

Further, the wane passes through the cylinder rotating pin and installs on the wane pillar, and the wane revolutes the rotating pin and rotates, and the wane left end is compressed tightly by wear-resisting button head and is hugged closely on thimble panel, and its right-hand member is 7mm apart from the lower extreme of kicking block, and the kicking block passes through the screw fastening and installs on the lower bottom surface of movable mould backing plate.

Further, the staggered tooth clamping ring plastic part is provided with two point gates G1 and G2 on the top end face for pouring, the staggered tooth clamping ring plastic part is provided with 24 clamping teeth, the 24 clamping teeth are spaced ring teeth, the clamping teeth comprise 12 three-layer clamping teeth and 12 single-layer clamping teeth, the three-layer clamping teeth and the single-layer clamping teeth are staggered, and the number of the pitched roof type sliding block sub-mechanisms is 12.

The demolding method of the demolding mechanism of the staggered-tooth clamping ring plastic part molding mold comprises the following steps of:

s1, after a P3 parting surface of a mold is opened, an ejector rod of an injection molding machine pushes an ejector pin panel and an ejector pin push plate to eject out, so that a push rod and a wane are synchronously ejected upwards, a push ring is pushed upwards by four leg rods, the push ring pushes 12 inclined ejection type slide blocks to eject upwards along a slide block guide block in an inclined mode, the sides of the 12 inclined ejection type slide blocks are ejected, side core pulling and demolding of 24 clamping teeth and the outer wall of a plastic part are completed, and the ejection distance is 7 mm;

synchronously, the mold core of the pushing piece is also ejected, and the mold core of the pushing piece pushes the plastic piece and the 12 inclined ejection type sliding blocks to move synchronously in the mold opening direction;

and S2, after the step S1 is completed, the ejector block blocks the right end of the warping plate, the ejector plate (the ejector pin panel and the ejector pin push plate) continues to move upwards, the left end of the warping plate is forced to drive the push piece core to continue ejecting, and the final demolding of the plastic piece is completed.

The invention has the beneficial effects that: this structural design has realized the automatic drawing of patterns of moulding a compound demoulding mechanism, in the mechanism, through the ejecting of liftout plate, four ejector pins are promoting the ejection ring in step, when come 24 latches drawing of patterns of lateral surface to accomplish 12 oblique top formula sliders, it is synchronous ejecting with the shaping core of moulding a piece to drive the wane formula mechanism simultaneously, accomplish the first ejecting and the lateral surface drawing of patterns action of moulding a piece, then it is ejecting through the continuation of liftout plate, drive wane mechanism will mould a piece ejecting completely and realize automatic drawing of patterns. The mechanism has ingenious conception and reasonable arrangement of parts, can effectively simplify the structure of the die and reduce the manufacturing cost of the die.

Drawings

FIG. 1a is a schematic structural view of a molded part of a staggered-tooth snap ring processed according to the present invention;

FIG. 1b is a schematic cross-sectional view of a machined interlocking teeth snap ring plastic part of the present invention;

FIG. 2 is a design drawing showing the parting of the molding cavity of the plastic part with staggered teeth and snap rings of the present invention;

FIG. 3 is a side schematic view of FIG. 2;

FIG. 4 is a top view of the moving mold of the present invention;

FIG. 5 is a bottom view of the stationary mold of the present invention;

FIG. 6 is a schematic cross-sectional view taken along line A-A of FIG. 4;

fig. 7 is a schematic cross-sectional view taken along line B-B in fig. 4.

Detailed Description

For the difficulty in forming the staggered-tooth snap ring plastic part, as shown in fig. 2, for the first difficult problem of forming a pouring system, because the inner wall has assembly requirements, the assembly effect cannot be influenced due to the existence of gate traces, and because the outer wall has 24 snap teeth, a side core-pulling mechanism needs to be arranged, the gate is not convenient to form, so that the gate can be formed only on the upper end surface and can be formed only in a point gate manner; the plastic part is a thin-wall annular plastic part, and the single gate is difficult to ensure the mold filling performance of the plastic part according to the size of the plastic part, so two point gates G1 and G2 are arranged on the top end surface of the plastic part for pouring. For the second difficulty, as for demolding of 24 latches, because demolding of annular side features is involved, the core-pulling demolding directions of the features are different, and 24 latches are spaced ring teeth, so that core pulling is implemented by using two simplified half sliders, the scheme is not feasible, only two sets of two single latches of two different latches can be combined together, and core-pulling demolding is implemented by using one side slider, obviously, for core-pulling demolding of the outer ring latch of the plastic part, 12 side core-pulling sliders need to be designed for core-pulling demolding. Wherein X1-X12 are serial numbers of the inclined top type sliding block mechanisms; P1-P4 are joint numbers.

Based on the above analysis, the parting design of the molding cavity of the plastic part is as shown in fig. 2 and fig. 3, and a P1 parting surface is adopted as a main parting surface of the plastic part, so as to ensure that the inclined top type sliding block mechanisms for side core pulling are all positioned on one side of the movable mold of the mold, thus facilitating the design and installation of the demolding mechanism and simplifying the mold structure. A P4 surface is used as a parting surface of an inner wall, P2 and P3 are used as parting surfaces of a molded piece with a set of characteristics, and 12 inclined top type sliders X1-X12 are divided. And one slider of the 12 pitched roof type sliders is used for completing side core-pulling and demolding of 1 three-layer latch and 1 single-layer latch.

After the pouring and demolding scheme for molding the plastic part is determined, the overall scheme of the mold can be basically determined, and the overall structural design of the mold of the plastic part is as follows.

As shown in fig. 4 to 7, in the design of the structure, the overall structure and the layout of the forming mold for the plastic part with the staggered-tooth snap ring, the basic structure of the mold adopts a three-plate type spot pouring gate structure in consideration of the requirement of the arrangement of a spot pouring gate system for the plastic part. The mold cavity layout is combined with the production requirement of the plastic part, and the mold cavity layout is arranged as 1 mold and 2 cavities.

The die comprises a fixed die plate 3, a movable die plate 4, a stripper plate 2 and a panel 1 which are arranged above the fixed die plate 3, wherein a cavity insert 22 is arranged in the fixed die plate 3, the side surface of the cavity insert 22 is provided with a pushing pin 26 and a pushing spring 25 which are matched with each other, the top of the cavity insert 22 is provided with a material pulling rod 23, the top of the cavity insert 22 is provided with a cavity insert locking block 27, the panel 1 is provided with a flange sprue bush 28, and the bottom of the flange sprue bush 28 is provided with a runner insert 29;

the bottom of the movable template 4 is provided with a template foot 6 and a bottom plate 7, a demoulding mechanism is arranged below the movable template 4, and the demoulding mechanism is suitable for ejecting the staggered-tooth clamping ring plastic part.

The cooling mainly cools the cavity insert 22, and due to the structural size, other formed parts are difficult to be provided with water channels, the cavity insert 22 is cooled by a ring groove water channel, and the water channel is sealed by a sealing ring 24.

Further, the demoulding mechanism comprises an inclined top type sliding block sub-mechanism, an ejection sub-mechanism of the inclined top type sliding block and a core warping plate ejection sub-mechanism, and the number of the inclined top type sliding block sub-mechanisms is 12.

In 12 pitched-roof-type sliding block sub-mechanisms on the outer wall, taking a single mechanism as an example, the pitched-roof-type sliding block sub-mechanism comprises a pitched-roof-type sliding block 42, a sliding block guide block 43 and a sliding block insert 44, wherein the sliding block guide block 43 is fixedly installed in a groove formed in the movable template 4 through a screw, a T-shaped rib is arranged on the sliding block guide block, the T-shaped rib is in sliding fit with a T-shaped groove formed in the pitched-roof-type sliding block 42 and used for guiding the upward oblique movement of the pitched-roof-type sliding block 42, and a limit screw is arranged at the upper end of the sliding block guide block 43 to prevent the pitched-roof-type sliding.

The ejector mechanism of the inclined ejector type sliding block comprises an integral annular ejector plate ring ejector ring 41 and four push rods 39, wherein the upper ends of the push rods 39 are fixedly connected with the ejector ring 41 through screws, the lower ends of the push rods 39 are arranged on the ejector pin panel 10, and the ejector ring 41 is ejected upwards through the upward ejection of the ejector pin panel 10 and the ejector pin ejector plate 11.

The core rocker ejector mechanism comprises an ejector block 34, a rocker support 35, a rocker 36, a wear-resistant round head 37, a pushing insert spring 38 and a pushing core 40, wherein an upper end disc of the pushing core 40 is a molding core of a staggered-tooth snap ring plastic part, the lower end of the pushing core is provided with a cylindrical rod-shaped handle, the lower end of the handle is sleeved in the guide cylindrical block 21, the bottom end of the handle is sleeved with the pushing insert spring 38 with a certain pre-compressed length, the spring is limited and locked by the wear-resistant round head 37, and the upper end of the pushing insert spring 38 abuts against the bottom surface of a cylindrical groove correspondingly formed in the movable die base plate 5. The wear-resistant round head 37 is made of a high-strength and wear-resistant T8A material.

The rocker 36 is installed on the rocker pillar 35 through a cylindrical rotating pin, the rocker 36 rotates around the rotating pin, the left end of the rocker 36 is tightly pressed by a wear-resistant round head 37 and tightly attached to the thimble panel 10, the distance between the right end of the rocker and the lower end of the ejector block 34 is 7mm, and the ejector block 34 is installed on the lower bottom surface of the movable die base plate 5 through screw fastening. The bottom of the movable die base plate 5 is provided with a reset rod 9, a reset rod spring 8 is sleeved on the reset rod 9, the reset rod 9 penetrates through the ejector pin panel 10 and the ejector pin push plate 11, an ejector pin plate guide pillar 12 is arranged on the ejector pin panel 10, an ejector pin plate guide sleeve 13 is sleeved on the ejector pin plate guide pillar 12, a garbage nail 14 is arranged at the bottom of the ejector pin push plate 11, and an anti-falling cushion block 15 is arranged at the bottom of the movable die base plate 5;

in addition, the fixed die plate 3 is provided with an auxiliary guide post 16, an auxiliary guide sleeve 17, a fixed die plate guide sleeve 18, a stripper plate guide sleeve 19 and a main guide post 20, the panel 1 is provided with a stripper plate pull rod 30, the fixed die plate 3 is provided with a resin shutter 31, a fixed die plate pull rod 32 is arranged between the fixed die plate 3 and the movable die plate 4, and the die feet 6 are provided with support posts 33.

The core wane ejector mechanism has the main functions of: when the ejector pin panel 10 and the ejector pin push plate 11 are ejected upwards by the ejector pin of the injection molding machine, the pushing rocker support 35 and the rocker 36 are ejected upwards synchronously, and as the rocker 36 is in contact with the ejector pin panel 10 and the wear-resistant round head 37, the combination of the wear-resistant round head 37 and the push piece core 40 is ejected upwards by the ejector pin panel 10 by overcoming the tension of the push insert spring 38, so that a plastic piece is pushed to be ejected, which is the first ejection of the mechanism. When the ejection distance exceeds 7mm, the right end of the wane 36 is blocked by the ejector block 34 to generate a lever effect, and due to the action of a lever arm, the left end of the wane 36 can accelerate to eject the combination of the wear-resistant round head 37 and the ejector core 40, so that the secondary ejection action of the sub-mechanism is realized.

Accordingly, the total demoulding action process of the special demoulding mechanism for the plastic part is as follows: the total demolding process is carried out in two steps, in the first step, after a P3 parting surface of a mold is opened, ejector rods of an injection molding machine push ejector pin panel 10 and an ejector pin push plate 11 to eject out, so that push rods 39 and a warping plate 36 are ejected upwards synchronously, four leg rods 39 push an ejection ring 41 to eject upwards, the ejection ring 41 pushes 12 pitched ejection type sliding blocks 42 to eject upwards obliquely along a sliding block guide block 43, the 12 pitched ejection type sliding blocks 42 are ejected at the same side, side core-pulling demolding of 24 clamping teeth and the outer wall of a plastic part is completed, and the ejection distance is 7 mm. In synchronism with this, the ejector core 40 is also ejected, which synchronizes the movement of the ejector slide 12 with the mold opening direction. After this step is completed, the ejector block 34 blocks the right end of the rocker 36, the ejector plate (the ejector pin panel 10 and the ejector pin push plate 11) continues to move upward, the left end of the rocker 36 is forced to drive the ejector core 40 to continue ejecting, and the final demolding of the plastic part is completed, which is the second step.

The working principle of the die is as follows: the mold is opened in a three-time parting manner, the opening sequence is PL1 → PL 2-PL 3, and after the mold is opened, the ejector rod of the injection molding machine pushes the ejector plates (the ejector pin panel 10 and the ejector pin push plate 11) to drive the rocker type secondary ejection demolding and circumferential inclined ejection sliding block side core-pulling demolding composite mechanism to perform automatic demolding of the plastic part. When the composite demolding mechanism is reset, the process is just opposite to the mold opening process, the ejector plate is reset firstly, the composite demolding mechanism is driven to reset firstly, and then the mold is reset and closed according to the sequence of PL3 → PL2 → PL 1.

Aiming at the problem of difficulty in pouring of the plastic part, the single cavity is provided with two point gates to finish pouring of the circular plastic part. The problem of difficult demoulding of 24 clamping teeth on the outer wall of a plastic part with staggered-tooth clamping rings is solved, a composite demoulding mechanism is designed to realize automatic demoulding of the plastic part, in the mechanism, ejection through an ejector plate is realized, four ejector rods are synchronously pushed to push an ejection ring so as to complete 12 pitched roof type sliding blocks to demould 24 clamping teeth on the side surface, meanwhile, a warping plate type mechanism is driven to synchronously eject a forming core of the plastic part, the first ejection and side demoulding actions of the plastic part are completed, then ejection is continued through the ejector plate, and the plastic part is completely ejected through the driving warping plate mechanism so as to realize automatic demoulding. The mechanism has ingenious conception and reasonable arrangement of parts, can effectively simplify the structure of the die and reduce the manufacturing cost of the die.

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are merely illustrative of the principles of the invention, but that various changes and modifications may be made without departing from the spirit and scope of the invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. The utility model provides a staggered teeth snap ring moulds demoulding mechanism of piece forming die, including top-inclined slider sub-mechanism, top-inclined slider's ejecting sub-mechanism and core wane ejecting sub-mechanism, a serial communication port, top-inclined slider sub-mechanism includes top-inclined slider (42), slider guide block (43), slider mold insert (44), slider guide block (43) are installed in the inslot that movable mould board (4) were seted up through screw fastening, be provided with T type muscle on it, T type groove sliding fit who sets up on this T type muscle and top-inclined slider (42) is used for the ascending slant motion direction of top-inclined slider (42), the upper end of slider guide block (43) is provided with a spacing screw and prevents that top-inclined slider (42) from slipping from slider guide block (43).

2. The demolding mechanism of the staggered-tooth clamp ring plastic part molding die as claimed in claim 1, wherein the ejection sub-mechanism of the inclined-ejection type sliding block comprises an integral annular ejector plate ring ejection ring (41) and four push rods (39), the upper ends of the push rods (39) are fixedly connected with the ejection ring (41) through screws, the lower ends of the push rods (39) are mounted on the ejector pin panel (10), and the ejection ring (41) is ejected upwards through upward ejection of the ejector pin panel (10) and the ejector pin push plate (11).

3. The demolding mechanism of the staggered-tooth snap ring plastic part molding mold as claimed in claim 2, wherein the core and rocker ejection sub-mechanism comprises an ejector block (34), a rocker support column (35), a rocker (36), a wear-resistant round head (37), a material pushing insert spring (38) and a pushing part core (40), an upper end disc of the pushing part core (40) is a molding core of the staggered-tooth snap ring plastic part, the lower end of the pushing part core is a cylindrical rod-shaped handle, the lower end of the handle is sleeved in the guide cylindrical block (21), after the material pushing insert spring (38) with a certain pre-compression length is sleeved at the bottom end of the handle, the spring is limited and locked by the wear-resistant round head (37), and the upper end of the material pushing insert spring (38) abuts against the bottom surface of a cylindrical groove correspondingly formed in the movable mold base plate (5).

4. The demolding mechanism for the staggered-tooth snap ring plastic part molding die as claimed in claim 3, wherein the wear-resistant round head (37) is made of a high-strength and wear-resistant T8A material.

5. The demolding mechanism of the staggered-tooth snap ring plastic part molding die as claimed in claim 3, wherein the rocker (36) is mounted on the rocker pillar (35) through a cylindrical rotating pin, the rocker (36) rotates around the rotating pin, the left end of the rocker (36) is tightly pressed and tightly attached to the ejector pin panel (10) through a wear-resistant round head (37), the distance between the right end of the rocker and the lower end of the ejector block (34) is 7mm, and the ejector block (34) is mounted on the lower bottom surface of the movable die base plate (5) through screw fastening.

6. The demolding mechanism for the staggered tooth snap ring plastic part forming mold as claimed in claim 1, wherein two point gates of G1 and G2 are arranged on the top end face of the staggered tooth snap ring plastic part for casting, the staggered tooth snap ring plastic part is provided with 24 snap teeth, the 24 snap teeth are spaced ring teeth, the snap teeth comprise 12 three-layer snap teeth and 12 single-layer snap teeth, the three-layer snap teeth and the single-layer snap teeth are staggered, and the number of the pitched roof type sliding block mechanism is 12.

7. A demoulding method of a demoulding mechanism of a staggered-tooth snap ring plastic part forming mould is characterized by comprising the following steps:

s1, after a P3 parting surface of a mold is opened, an ejector rod of an injection molding machine pushes an ejector pin panel (10) and an ejector pin push plate (11) to eject, so that a push rod (39) and a warping plate (36) are synchronously ejected upwards, four leg rods (39) push an ejection ring (41) to eject upwards, the ejection ring (41) pushes 12 inclined ejection type slide blocks (42) to eject upwards along a slide block guide block (43) in an inclined mode, the 12 inclined ejection type slide blocks (42) are ejected at the same side, side core pulling and demolding of 24 clamping teeth and the outer wall of a plastic part are completed, and the ejection distance is 7 mm;

synchronously, the ejector core (40) is also ejected, and the ejector core pushes the plastic part to be synchronous with the movement of 12 inclined ejection type sliding blocks (42) in the mold opening direction;

s2, after the step S1 is completed, the ejector block (34) blocks the right end of the warping plate (36), the ejector plates (the ejector pin panel 10 and the ejector pin push plate 11) continue to move upwards, the left end of the warping plate (36) is forced to drive the ejector core (40) to continue ejecting, and the final demolding of the plastic part is completed.

8. The method for demoulding the demoulding mechanism of the staggered-tooth snap ring plastic part forming mould as claimed in claim 7, wherein the mould is opened in three parting steps, the opening sequence is PL1 → PL 2-PL 3, after the mould is opened, the ejector rod of the injection molding machine pushes the ejector plate (the ejector pin panel 10 and the ejector pin push plate 11) to drive the demoulding mechanism to carry out automatic demoulding of the plastic part, the resetting process is just opposite to the mould opening process, the ejector plate is reset firstly, the demoulding mechanism is driven to reset firstly, and then the mould is reset and closed according to the sequence of PL3 → PL2 → PL 1.