Front and back pressure maintaining needle withdrawing structure

Abstract

The invention discloses a front-back pressure maintaining needle withdrawing structure which comprises a bottom plate. The two sides of the top of the bottom plate are each provided with a supporting block, and a plate B is arranged on the supporting blocks; the plate A, the hot runner base plate and the panel are sequentially arranged on the plate B from bottom to top; a rear mold core is mounted at the top of the plate B, and a front mold core is mounted at the position, corresponding to the rear mold core, of the bottom of the plate A. The mold further comprises a front pressure-maintaining needle withdrawing mechanism mounted on the plate A and a rear pressure-maintaining needle withdrawing mechanism mounted in the middle of the top of the bottom plate; the front pressure maintaining needle withdrawing mechanism comprises a front insert and a front pressure maintaining lifting assembly. Through mutual cooperation of the front pressure-maintaining needle withdrawing mechanism and the rear pressure-maintaining needle withdrawing mechanism, the problems of punching deviation, deformation, glue shortage, burr, copper exposure and the like of hardware caused by injection pressure and high temperature in the die sleeving process can be solved, and the quality and the use performance of products are guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of plastic molds, and particularly to a front and rear pressure-holding and needle-retracting structure. Background Art

[0002] In plastic mold production, it is often necessary to embed metal parts into plastic for insert molding production. However, when the metal parts are large or thin, they are prone to being displaced by the injection pressure during the insert molding process and are also prone to deformation at a relatively high plastic melt temperature. These problems can lead to defects such as missing glue, flash, and exposed copper in the product, seriously affecting the product quality and service performance. To solve these problems, existing conventional methods include changing the structure of the metal parts (such as turning them into multiple small metal parts), hardening the material of the metal parts, or adopting a scheme of multiple local insert moldings for shaping. However, these methods not only reduce production efficiency but also increase production costs and may have an adverse impact on the service performance of the product. Summary of the Invention

[0003] The purpose of the present invention is to provide a front and rear pressure-holding and needle-retracting structure to solve the problems of displacement, deformation, missing glue, flash, and exposed copper of metal parts during the insert molding process due to injection pressure and high temperature, ensuring the product quality and service performance.

[0004] To achieve the above purpose, the following technical solutions are adopted:

[0005] A front and rear pressure-holding and needle-retracting structure includes a bottom plate; two support blocks are installed on both sides of the top of the bottom plate, and a B plate is arranged on the support blocks; an A plate, a hot runner backing plate, and a panel are arranged on the B plate in sequence from bottom to top; a rear mold core is installed on the top of the B plate, and a front mold core is installed at the corresponding position of the bottom of the A plate and the rear mold core. It also includes a front pressure-holding and needle-retracting mechanism installed on the A plate and a rear pressure-holding and needle-retracting mechanism installed in the middle of the top of the bottom plate; the front pressure-holding and needle-retracting mechanism includes a front insert and a front pressure-holding lifting assembly; a first accommodation groove is formed in the A plate, and the front insert is movably arranged in the first accommodation groove; a front insert pin is also installed at the bottom of the front insert, and one end of the front insert pin is movably inserted into the front mold core; the front pressure-holding lifting assembly is installed on the A plate and connected to the front insert, and the front pressure-holding lifting assembly is used to drive the front insert to drive the front insert pin to do lifting motion.

[0006] Further, a second accommodation groove is formed at one end of the top of the A plate, and a first limiting groove communicating with the second accommodation groove is further formed along the length direction of the top of the A plate; the first accommodation groove is formed in the first limiting groove; the front pressure-holding lifting assembly includes a front oil cylinder installed at one end of the A plate, a first connecting rod connected to the output shaft of the front oil cylinder, a front positioning seat movably arranged in the second accommodation groove and connected to the first connecting rod, a second connecting rod connected to one side of the front positioning seat, and a positioning push rod movably arranged in the first limiting groove and connected to the second connecting rod; a guiding notch is obliquely formed downward at the position corresponding to the bottom of the positioning push rod and the first accommodation groove, and a guiding seat is integrally connected obliquely downward to the inner wall of the top of the guiding notch; the front insert is slidably connected to the guiding seat, and an inclined surface that fits the inner wall of the top of the guiding notch is formed at the top of the front insert.

[0007] Further, guiding chutes are obliquely formed downward along the length direction on both sides of the guiding seat; a guiding connection block is connected to each of the two sides of the top of the front insert; the guiding connection block is of an L-shaped structure, the vertical ends of the L-shaped of the two guiding connection blocks are integrally connected to one side of the top of the front insert respectively, and the horizontal ends of the L-shaped of the two guiding connection blocks are respectively movably inserted into a guiding chute for arrangement.

[0008] Further, a wear-resistant block is further installed at the position corresponding to the top of the positioning push rod and the guiding notch.

[0009] Further, a second limiting groove is further formed at the top of the A plate; one end of the second limiting groove communicates with the second accommodation groove, and the other end of the second limiting groove penetrates to one end of the A plate; the first connecting rod is movably arranged in the second limiting groove.

[0010] Further, the rear pressure-holding needle-retracting mechanism includes two rear oil cylinders and a rear lifting seat; the two rear oil cylinders are respectively arranged vertically at one end of the top of the bottom plate, and the two ends of the bottom of the rear lifting seat are respectively connected to the output shafts of a rear oil cylinder; a third accommodation groove is further formed at the bottom of the B plate, and the upper part of the rear lifting seat is movably arranged in the third accommodation groove; a rear insert needle is further installed on the rear lifting seat, and one end of the rear insert needle is movably inserted into the rear mold core for arrangement.

[0011] Further, a limiting screw is further installed on the rear lifting seat, and the upper part of the limiting screw extends upward through the top of the rear lifting seat; a limiting groove is further formed at the bottom of the B plate corresponding to the limiting screw.

[0012] Further, guiding blocks are further installed on both sides of the rear lifting seat, and guiding holes are formed in the guiding blocks; guiding columns are further installed at the positions corresponding to the guiding blocks on the top of the supporting block, and the guiding blocks are movably sleeved on the guiding columns through the guiding holes.

[0013] Further, one end of the rear lifting seat is also connected with a connecting rod; the connecting rod is of an L-shaped structure, the L-shaped horizontal end of the connecting rod is connected with the rear lifting seat, and the L-shaped vertical end of the connecting rod is arranged at one end of the B plate; an induction block is also installed on the L-shaped vertical end of the connecting rod; a stroke switch is installed on each of the upper and lower parts at one end of the B plate, and the induction block is located between the two stroke switches.

[0014] Adopting the above scheme, the beneficial effects of the present invention are:

[0015] Through the mutual cooperation of the front and rear pressure-holding and needle-retracting mechanisms, problems such as offset punching, deformation, lack of glue, flash, exposed copper, etc. that occur to the hardware parts during the process of overmolding can be solved, ensuring the quality and service performance of the products. At the same time, inefficient schemes such as multiple local overmoldings are avoided, reducing the production processes and production time, thereby significantly improving the production efficiency. Description of the Drawings

[0016] Figure 1 is a schematic structural diagram of the present invention;

[0017] Figure 2 is Figure 1 a sectional view of one of the perspectives;

[0018] Figure 3 is Figure 1 a sectional view of another perspective;

[0019] Figure 4 is a schematic structural diagram of the present invention omitting the hot runner backing plate and the panel;

[0020] Figure 5 is a schematic structural diagram of the A plate of the present invention;

[0021] Figure 6 is a schematic structural diagram of the front pressure-holding and needle-retracting mechanism of the present invention;

[0022] Figure 7 is a schematic structural diagram of the front pressure-holding and needle-retracting mechanism of the present invention omitting some structures;

[0023] Figure 8 is a schematic structural diagram of the bottom plate, the rear pressure-holding and needle-retracting mechanism and the B plate of the present invention;

[0024] Figure 9 is a schematic structural diagram of the rear pressure-holding and needle-retracting mechanism and the bottom plate of the present invention;

[0025] Among them, the description of the attached drawing reference numerals:

[0026] 1. Bottom plate; 2. Support block; 3. B plate; 4. A plate; 5. Hot runner backing plate; 6. Panel; 7. Front pressure-holding and needle-retracting mechanism; 8. Rear pressure-holding and needle-retracting mechanism; 31. Rear mold core; 41. Front mold core; 42. First accommodating groove; 43. Second accommodating groove; 44. First limiting groove; 45. Second limiting groove; 71. Front insert; 72. Front needle; 73. Front oil cylinder; 74. First connecting rod; 75. Front slider base; 76. Second connecting rod; 77. Slide push rod; 78. Guide seat; 79. Wear-resistant block; 70. Limit stop block; 81. Rear oil cylinder; 82. Rear lifting seat; 83. Rear needle; 84. Limit screw; 711. Guide connection block; 781. Guide chute; 821. Guide block; 822. Guide post; 823. Connecting rod; 824. Induction block; 825. Travel switch. Detailed implementation mode

[0027] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0028] Refer to Figures 1 to 9 As shown, the present invention provides a front and rear pressure-holding and needle-retracting structure, including a bottom plate 1; two support blocks 2 are respectively installed on both sides of the top of the bottom plate 1, and a B plate 3 is arranged on the support blocks 2; an A plate 4, a hot runner backing plate 5 and a panel 6 are sequentially arranged on the B plate 3 from bottom to top; a rear mold core 31 is installed on the top of the B plate 3, and a front mold core 41 is installed at the corresponding position of the bottom of the A plate 4 and the rear mold core 31. In one embodiment, it further includes a front pressure-holding and needle-retracting mechanism 7 installed on the A plate 4, and a rear pressure-holding and needle-retracting mechanism 8 installed in the middle of the top of the bottom plate 1; the front pressure-holding and needle-retracting mechanism 7 includes a front insert 71 and a front pressure-holding lifting assembly; a first accommodating groove 42 is formed in the A plate 4, and the front insert 71 is movably arranged in the first accommodating groove 42; a front needle 72 is further installed at the bottom of the front insert 71, and one end of the front needle 72 is movably inserted into the front mold core 41; the front pressure-holding lifting assembly is installed on the A plate 4 and connected to the front insert 71, and the front pressure-holding lifting assembly is used to drive the front insert 71 to drive the front needle 72 to perform lifting motion.

[0029] Continue to refer to Figure 6 As shown, the product targeted by the present invention is a plastic-coated large copper bar, made of PPS+GF20 material, with a 0.5-mm-thick copper hardware part to be inserted in the middle. The thickness of the upper and lower rubber positions of the hardware part is 1.5 mm. The hardware part is prone to deformation when heated, and at the same time, the hardware part is relatively thin and is prone to being offset by the injection pressure, resulting in problems such as lack of glue, flash, and exposed copper. Therefore, in this application, a front pressure-holding and needle-retracting mechanism 7 and a rear pressure-holding and needle-retracting mechanism 8 are respectively designed at the suspended parts of the upper (top) and lower (bottom) parts of the hardware part to solve the above problems.

[0030] Continue to refer to Figures 1 to 9As shown, in this embodiment, a second accommodation groove 43 is formed at one end of the top of the A plate 4, and a first limiting groove 44 communicating with the second accommodation groove 43 is further formed along the length direction of the top of the A plate 4; the first accommodation groove 42 is formed in the first limiting groove 44; the front pressure-holding lifting assembly includes a front oil cylinder 73 installed at one end of the A plate 4, a first connecting rod 82374 connected to the output shaft of the front oil cylinder 73, a front positioner seat 75 movably arranged in the second accommodation groove 43 and connected to the first connecting rod 82374, a second connecting rod 82376 connected to one side of the front positioner seat 75, and a positioner push rod 77 movably arranged in the first limiting groove 44 and connected to the second connecting rod 82376; a guiding notch is obliquely formed downward at the position corresponding to the bottom of the positioner push rod 77 and the first accommodation groove 42, and a guiding seat 78 is integrally connected obliquely downward to the inner wall of the top of the guiding notch; the front insert 71 is slidably connected to the guiding seat 78, and an inclined surface that fits the inner wall of the top of the guiding notch is formed at the top of the front insert 71.

[0031] In this embodiment, there are two rear mold cores 31 and two front mold cores 41, and two products can be injection-molded simultaneously. Correspondingly, the number of the second connecting rods 82376 and the positioner push rods 77 is also set to two groups, which are respectively arranged corresponding to one front mold core 41; two first accommodation grooves 42 are formed in each first limiting groove 44, and the first accommodation grooves 42 are correspondingly formed at the positions on the top of the hardware part that need to be suspended. One front insert 71 is arranged in each first accommodation groove 42 (correspondingly, two guiding notches are formed at the bottom of the positioner push rod 77), and two front pins 72 are installed at the bottom of each front insert 71; driven by the front oil cylinder 73, the positioner push rod 77 can be driven to move in the first limiting groove 44 through the first connecting rod 82374, the front positioner seat 75, and the second connecting rod 82376. When the positioner push rod 77 moves in the first limiting groove 44, since the front insert 71 is slidably connected to the guiding seat 78, the front insert 71 will move relative to the guiding seat 78. And since the front insert 71 is arranged in the first accommodation groove 42, the inner wall of the first accommodation groove 42 will limit the front insert 71, so that when the front insert 71 moves relative to the guiding seat 78, it can only move up and down, thereby driving the front pins 72 to lift, so that the front pins 72 contact or move away from the top of the hardware part, thereby applying or canceling the downward pressure to the top of the hardware part (when applying the downward pressure, that is, pressing down on the top of the hardware part to realize the limit in the height direction of the hardware part to prevent it from being offset or deformed), so as to meet the normal production of such products.

[0032] In a preferred embodiment, guiding chutes 781 are inclined downward along the length direction on both sides of the guiding seat 78; on both sides of the top of the front insert 71, a guiding connection block 711 is connected respectively; the guiding connection block 711 is of an L-shaped structure, the vertical ends of the L-shaped of the two guiding connection blocks 711 are integrally connected to one side of the top of the front insert 71 respectively, and the horizontal ends of the L-shaped of the two guiding connection blocks 711 are respectively inserted into a guiding chute 781 movably; a second limiting groove 45 is further formed at the top of the A plate 4; one end of the second limiting groove 45 communicates with the second accommodating groove 43, and the other end of the second limiting groove 45 penetrates through to one end of the A plate 4; the first connecting rod 82374 is movably arranged in the second limiting groove 45.

[0033] The horizontal end of the L-shaped of the guiding connection block 711 is inserted into the guiding chute 781, so as to realize the sliding connection between the front insert 71 and the guiding seat 78. When the slide push rod 77 moves, the front insert 71 can move up and down along the guiding chute 781. The guiding chute 781 can guide the lifting of the front insert 71 to ensure the accuracy of its movement. In addition, a wear-resistant block 79 is further installed at the corresponding position of the top of the slide push rod 77 and the guiding notch, which can reduce wear; in this embodiment, the two guiding notches on the slide push rod 77 are respectively formed at both ends of its bottom, as Figure 7 shown. In order to limit the movement stroke of one of the front inserts 71, a limiting block 70 is further connected to the end of the slide push rod 77 far away from the front oil cylinder 73.

[0034] In one embodiment, the post-pressure needle retracting mechanism 8 includes two post oil cylinders 81 and a post lifting seat 82; the two post oil cylinders 81 are respectively arranged at one end of the top of the bottom plate 1 along the vertical direction, and both ends of the bottom of the post lifting seat 82 are connected to the output shafts of a post oil cylinder 81 respectively; a third accommodating groove is further formed at the bottom of the B plate 3, and the upper part of the post lifting seat 82 is movably arranged in the third accommodating groove; a post insert needle 83 is further installed on the post lifting seat 82, and one end of the post insert needle 83 is movably inserted into the post mold core 31. The position of the post insert needle 83 is at the suspended part at the bottom of the hardware part, and its quantity and distribution are set according to the actual structure of the product. The post oil cylinder 81 can drive the lifting seat to drive the post insert needle 83 to lift, so that the post insert needle 83 contacts or is away from the bottom of the hardware part, thereby applying or canceling the upward pressure to the bottom of the hardware part (when applying the upward pressure, that is, pressing the bottom of the hardware part to realize the limit in the height direction of the hardware part to prevent it from being offset or deformed), so as to meet the normal production of such products.

[0035] Meanwhile, a limit screw 84 is also installed on the rear lifting seat 82, and the upper part of the limit screw 84 passes through the top of the rear lifting seat 82 and extends upward; a limit groove is also provided at the bottom of the B plate 3 corresponding to the limit screw 84. The limit screw 84 can limit the upward stroke of the rear lifting seat 82. In addition, guide blocks 821 are installed on both sides of the rear lifting seat 82, and guide holes are provided in the guide blocks 821; guide posts 822 are also installed at the top of the support block 2 corresponding to the guide blocks 821, and the guide blocks 821 are movably sleeved on the guide posts 822 through the guide holes. When the rear lifting seat 82 moves up and down, it can be guided by the guide posts 822 and the guide blocks 821. At the same time, in order to prevent the rear lifting seat 82 from moving up and down excessively, it is necessary to limit and control the lifting stroke of the rear lifting seat 82. Therefore, in a preferred embodiment, one end of the rear lifting seat 82 is also connected with a connecting rod 823; the connecting rod 823 is of an L-shaped structure, the L-shaped horizontal end of the connecting rod 823 is connected to the rear lifting seat 82, and the L-shaped vertical end of the connecting rod 823 is arranged at one end of the B plate 3; an induction block 824 is also installed on the L-shaped vertical end of the connecting rod 823; a stroke switch 825 is installed on the upper and lower parts of one end of the B plate 3 respectively, and the induction block 824 is located between the two stroke switches 825. Through the induction block 824 and the stroke switch 825, the background can detect the position of the rear lifting seat 82 in real time, ensuring the safety of its operation.

[0036] In actual use, the front oil cylinder 73 drives the slider push rod 77 to move the front insert 71 and the front ejector pin 72 by 1.5 mm, which is the rubber position thickness at the top (upper section) of the product; and the two rear oil cylinders 81 drive the rear lifting seat 82 and the rear ejector pin 83 to move by 1.5 mm as well, which is the rubber position thickness at the bottom (lower section) of the product; the specific working process is as follows:

[0037] Start injecting glue. One second before the end of the injection (this is controlled by time, or it can also be controlled by the injection position), the injection molding machine neutron supplies oil to the front oil cylinder 73 and the rear oil cylinder 81, driving the front ejector pin 72 and the rear ejector pin 83 to retreat 1.5 mm. At this time, it enters the holding pressure stage. Using the pressure of the holding pressure, the holes of the front ejector pin 72 and the rear ejector pin 83 are filled to the full glue state (ensuring the appearance requirements of the product), then it is cooled. Next, the A / B plates 3 are opened, the product is ejected, the overmolded metal part is placed in, the A / B plates 3 are closed, the injection molding machine neutron supplies oil to the front oil cylinder 73 and the rear oil cylinder 81, realizing the reset of the front ejector pin 72 and the rear ejector pin 83, that is, pressing the metal part to achieve height direction limit (preventing it from being offset or deformed), and then start injecting glue to enter the next working cycle.

[0038] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A front and rear pressure-holding and needle-retracting structure, comprising a bottom plate; on both sides of the top of the bottom plate, a support block is installed respectively, and a B plate is arranged on the support block; on the B plate, an A plate, a hot runner backing plate and a panel are arranged in sequence from bottom to top; a rear mold core is installed on the top of the B plate, and a front mold core is installed at the position corresponding to the rear mold core at the bottom of the A plate, characterized in that, It further includes a front pressure-holding and needle-retracting mechanism installed on the A plate, and a rear pressure-holding and needle-retracting mechanism installed in the middle of the top of the bottom plate; the front pressure-holding and needle-retracting mechanism includes a front insert and a front pressure-holding lifting assembly; a first accommodation groove is formed in the A plate, and the front insert is movably arranged in the first accommodation groove; a front insert needle is further installed at the bottom of the front insert, and one end of the front insert needle is movably inserted into the front mold core for arrangement; the front pressure-holding lifting assembly is installed on the A plate and connected to the front insert, and the front pressure-holding lifting assembly is used to drive the front insert to drive the front insert needle to perform lifting movement.

2. The front and rear pressure-holding and needle-retracting structure according to claim 1, wherein A second accommodation groove is formed at one end of the top of the A plate, and a first limiting groove communicating with the second accommodation groove is further formed along the length direction of the top of the A plate; the first accommodation groove is formed in the first limiting groove; the front pressure-holding lifting assembly includes a front oil cylinder installed at one end of the A plate, a first connecting rod connected to the output shaft of the front oil cylinder, a front travel seat movably arranged in the second accommodation groove and connected to the first connecting rod, a second connecting rod connected to one side of the front travel seat, and a travel push rod movably arranged in the first limiting groove and connected to the second connecting rod; a guiding notch is obliquely downward formed at the position corresponding to the bottom of the travel push rod and the first accommodation groove, and a guiding seat is integrally connected obliquely downward to the inner wall of the top of the guiding notch; the front insert is slidably connected to the guiding seat, and an inclined surface fitting the inner wall of the top of the guiding notch is formed at the top of the front insert.

3. The front and rear pressure-holding and needle-retracting structure according to claim 2, characterized in that, Guiding chutes are obliquely downward formed along the length direction on both sides of the guiding seat; a guiding connection block is connected to each of the two sides of the top of the front insert; the guiding connection block is of an L-shaped structure, the L-shaped vertical ends of the two guiding connection blocks are integrally connected to one side of the top of the front insert respectively, and the L-shaped horizontal ends of the two guiding connection blocks are respectively movably inserted into a guiding chute for arrangement.

4. The front and rear pressure-holding and needle-retracting structure according to claim 3, wherein, A wear-resistant block is further installed at the position corresponding to the top of the travel push rod and the guiding notch.

5. The front and rear pressure-holding and needle-retracting structure according to claim 3, wherein, A second limiting groove is further formed at the top of the A plate; one end of the second limiting groove communicates with the second accommodation groove, and the other end of the second limiting groove penetrates to the end of one end of the A plate; the first connecting rod is movably arranged in the second limiting groove.

6. The front and rear pressure-holding and needle-retracting structure according to claim 1, characterized in that, The rear pressure-holding and needle-retracting mechanism includes two rear oil cylinders and a rear lifting seat; the two rear oil cylinders are respectively arranged vertically at one end of the top of the bottom plate, and the two ends of the bottom of the rear lifting seat are respectively connected to the output shafts of one rear oil cylinder; a third accommodation groove is formed at the bottom of the B plate, and the upper part of the rear lifting seat is movably arranged in the third accommodation groove; a rear insert needle is further installed on the rear lifting seat, and one end of the rear insert needle is movably inserted into the rear mold core for arrangement.

7. The front and rear pressure-holding and needle-retracting structure according to claim 6, wherein A limiting screw is further installed on the rear lifting seat, and the upper part of the limiting screw extends upward through the top of the rear lifting seat; a limiting groove is further formed at the bottom of the B plate corresponding to the limiting screw.

8. The front and rear pressure-holding and needle-retracting structure according to claim 6, wherein Guide blocks are further installed on both sides of the rear lifting seat, and guide holes are formed in the guide blocks; guide columns are further installed at the positions corresponding to the guide blocks at the top of the support block, and the guide blocks are movably sleeved on the guide columns through the guide holes.

9. The front and rear pressure-holding and needle-retracting structure according to claim 6, characterized in that, One end of the rear lifting seat is also connected with a connecting rod; the connecting rod is in an L-shaped structure, the L-shaped horizontal end of the connecting rod is connected with the rear lifting seat, and the L-shaped vertical end of the connecting rod is arranged at one end of the B plate; an induction block is also installed on the L-shaped vertical end of the connecting rod; one upper part and one lower part of one end of the B plate are each installed with a travel switch, and the induction block is located between the two travel switches.

Images