The secondary shrinkage core structure of an injection mold

Abstract

The present invention discloses a secondary core-retracting structure for an injection mold, which includes a panel, a sprue plate, an A plate, a B plate, a core-retracting plate, and a bottom plate that are sequentially installed from top to bottom. The panel is used for mold clamping and the placement of the locating ring. A glue injection runner is provided between the sprue plate and the A plate for delivering the rubber material. The B plate is used for placing the mold core. A core-pulling mechanism is provided on the core-retracting plate for demolding. A glue pulling device is provided between the B plate and the A plate to provide a pulling force between the B plate and the A plate for controlling the mold opening sequence. A buckle base is provided between the core-retracting plate and the B plate to provide a pulling force between the core-retracting plate and the B plate for controlling the mold opening sequence. The present invention realizes secondary core-retracting through the design of the core-pulling mechanism, solves the problem of difficult demolding of box-shaped products with undercuts, simplifies the mold structure, reduces the mold design and production costs, effectively avoids product damage, and ensures the normal production of products.

Description

Technical Field

[0001] The present invention relates to the technical field of injection molds, and particularly to a secondary core shrinking structure of an injection mold. Background Art

[0002] With the development of injection molding technology, existing injection molding methods have been able to achieve the one-time injection molding of relatively complex box-shaped products within a set of molds; as shown in the attached instructions, Figure 1 the inner side of product a has multiple undercuts a1, and the forming grooves for forming these undercuts a1 are generally designed on the lifters; during mold opening, affected by the shape characteristics of the product, it is necessary to first complete the core pulling of the undercuts a1 of product a and then complete the demolding action of the product, otherwise the product is easily pulled and deformed; however, the existing core pulling and demolding structures cannot effectively demold such relatively complex products, resulting in product damage or difficult demolding, interfering with the normal production of the product; on the other hand, even if the existing core pulling and demolding structures can achieve the demolding function of such box-shaped products with undercuts, it will make the mold structure very complex, with a large mold design difficulty, increasing the cost of mold design and production.

[0003] Therefore, there are defects in the prior art and improvements are needed. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a secondary core shrinking structure of an injection mold.

[0005] The technical solution of the present invention is as follows: A secondary core shrinking structure of an injection mold includes a panel, a sprue plate, a plate A, a plate B, a core shrinking plate, and a bottom plate that are sequentially installed from top to bottom; the panel is used for mold clamping and placing the locating ring; a glue injection runner is provided between the sprue plate and plate A for feeding the rubber material; several mold cores are placed on the plate B; a core pulling mechanism matching the number of several mold cores is provided on the core shrinking plate for core shrinking and demolding;

[0006] Several glue pulling members are provided between the plate B and the plate A to provide a pulling force between the plate B and the plate A, playing a role in controlling the mold opening sequence;

[0007] Several buckle bases are provided between the core shrinking plate and the plate B to provide a pulling force between the core shrinking plate and the plate B, playing a role in controlling the mold opening sequence.

[0008] Preferably, a number of first stroke tie rods are provided on the panel; the bottoms of the number of first stroke tie rods penetrate through the panel, and the sprue plate, A plate, B plate, core-pulling plate and bottom plate are sequentially placed on the number of first stroke tie rods from top to bottom; during mold opening, the first stroke tie rods abut against the A plate, providing a pulling force to the A plate and playing an auxiliary role in mold opening.

[0009] Preferably, a number of first screw mounting grooves are further provided on the panel, and a first stop screw is installed in each first screw mounting groove. Each first stop screw penetrates through the first screw mounting groove and is fixedly arranged on the sprue plate; during mold opening, the first stop screw abuts against the panel, playing a limiting role on the panel through the first stop screw.

[0010] Preferably, a number of second stroke tie rods are provided on the sprue plate. The bottoms of the number of second stroke tie rods penetrate through the sprue plate, and the A plate and B plate are sequentially placed on the number of second stroke tie rods from top to bottom; during mold opening, the second stroke tie rods abut against the A plate, providing a pulling force to the A plate and playing an auxiliary role in mold opening.

[0011] Preferably, each core-pulling mechanism is composed of a slide block base, a first slide block insert and a number of second slide block inserts; each slide block base is arranged on the core-pulling plate corresponding to the position of the mold core; a first mounting groove is provided in the slide block base, and the first slide block insert can be slidably placed in the first mounting groove, and the bottom of the first slide block insert is connected to the bottom plate; a number of inclined platforms matching the number of the second slide block inserts are provided at the top of the first slide block insert, a second mounting groove is provided in the slide block base corresponding to each inclined platform, and each second slide block insert can be slidably placed in each second mounting groove, and each second slide block insert is provided with an inclined groove, and the first slide block insert and the second slide block inserts are connected through the inclined platforms and the inclined grooves.

[0012] Preferably, a number of second screw mounting grooves are further provided on the core-pulling plate, and a second stop screw is installed in each second screw mounting groove. Each second stop screw penetrates through the second screw mounting groove and is fixedly arranged on the bottom plate; during mold opening, the core-pulling plate abuts against the second stop screw, playing a limiting role on the core-pulling plate through the second stop screw.

[0013] Preferably, a number of third stroke tie rods are arranged on the bottom plate, and the tops of the number of third stroke tie rods penetrate through the bottom plate. The sprue plate, A plate, B plate, and shrink core plate are placed on the number of third stroke tie rods in sequence from top to bottom. When the mold is opened, the B plate abuts against the third stroke tie rod, and a pulling force is provided to the B plate through the third stroke tie rod, playing an auxiliary role in mold opening.

[0014] Adopting the above scheme, the present invention has the following beneficial effects:

[0015] 1. The present invention realizes secondary shrink core through the design of the core-pulling mechanism. Compared with the prior art, the present invention solves the problem of difficult demolding of box-shaped products with undercuts, simplifies the mold structure, reduces the mold design and production costs, effectively avoids product damage, and ensures the normal production of products.

[0016] 2. In the preferred scheme, the application of the pull glue and the buckle base effectively plays a role in controlling the mold opening sequence. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on the structures shown in these drawings without creative efforts.

[0018] Figure 1 It is a three-dimensional structure schematic diagram of a product in the prior art;

[0019] Figure 2 It is a three-dimensional structure schematic diagram of the present invention;

[0020] Figure 3 It is a top view of the present invention;

[0021] Figure 4 For Figure 3 The sectional view from the A-A perspective in

[0022] Figure 5 For Figure 3 The sectional view from the B-B perspective in

[0023] Figure 6 For Figure 3 The sectional view from the C-C perspective in

[0024] Figure 7 It is a three-dimensional structure schematic diagram of the present invention after removing the panel, sprue plate, and A plate;

[0025] Figure 8This is a three-dimensional structural schematic diagram of the core-pulling mechanism of the present invention.

[0026] The realization of the object of the present invention, functional features and advantages will be further described in conjunction with embodiments with reference to the accompanying drawings. Specific embodiments

[0027] The following will describe the present invention in detail in conjunction with the accompanying drawings and specific embodiments.

[0028] Referring to Figures 2 to 8 As shown, the present invention provides a secondary core-shrinking structure for an injection mold, which includes a panel 1, a sprue plate 2, a plate A 3, a plate B 4, a core-shrinking plate 5 and a bottom plate 6 installed in sequence from top to bottom. The panel 1 is used for mold clamping and placing the locating ring. A glue injection runner is arranged between the sprue plate 2 and the plate A 3 for feeding the rubber material. The plate B 4 is used for placing the mold core. A core-pulling mechanism 7 is arranged on the core-shrinking plate 5 for core-shrinking demoulding;

[0029] Four first stroke pull rods 11 are arranged on the panel 1. The bottoms of the four first stroke pull rods 11 pass through the panel 1. The sprue plate 2, the plate A 3, the plate B 4, the core-shrinking plate 5 and the bottom plate 6 are placed on the four first stroke pull rods 11 in sequence from top to bottom. And a first stroke is arranged between the plate A 3, the plate B 4, the core-shrinking plate 5 and the bottom plate 6. When the first stroke pull rod 11 moves upward to the maximum stroke of the first stroke, the first stroke pull rod 11 abuts against the plate A 3, and a pulling force is provided to the plate A 3 through the first stroke pull rod 11, playing an auxiliary mold-opening role;

[0030] Four first screw installation grooves with a first limit stroke preset are also arranged on the panel 1. A first thimble screw 12 is installed in each first screw installation groove. Each first thimble screw 12 passes through the first screw installation groove and is fixedly arranged on the sprue plate 2. When the panel 1 moves upward to the maximum stroke of the first limit stroke, the panel 1 abuts against the first thimble screw 12, and the first thimble screw 12 plays a limiting role on the panel 1;

[0031] Four second stroke pull rods 21 are arranged on the sprue plate 2. The bottoms of the four second stroke pull rods 21 pass through the sprue plate 2. The plate A 3 and the plate B 4 are placed on the four second stroke pull rods 21 in sequence from top to bottom. And a second stroke is arranged between the plate A 3 and the plate B 4. When the second stroke pull rod 21 moves upward to the maximum stroke of the second stroke, the second stroke pull rod 21 abuts against the plate A 3, and a pulling force is provided to the plate A 3 through the second stroke pull rod 21, playing an auxiliary mold-opening role;

[0032] Two of the mold cores are fixed on the A plate 3. Correspondingly, mold core positioning grooves are provided on the B plate 4 at positions corresponding to each mold core for placing the mold cores; four positioning pins are respectively arranged in each mold core positioning groove. Correspondingly, four positioning pin holes are provided at the bottom of each mold core at positions corresponding to the positioning pins one by one. When the mold is closed, each positioning pin is correspondingly inserted into the positioning pin hole for positioning and fixing the mold core;

[0033] Eight glue pulls 8 are arranged between the B plate 4 and the A plate 3 to provide a pulling force between the B plate 4 and the A plate 3, playing a role in controlling the mold opening sequence;

[0034] Two core-pulling mechanisms 7 are arranged on the core-retracting plate 5. Each core-pulling mechanism 7 is composed of a slider base 71, a first slider insert 72 and four second slider inserts 73; slider mounting grooves are provided on the core-retracting plate 5 at positions corresponding to each mold core, and the slider base 71 is fixedly installed in each slider mounting groove; a first mounting groove is arranged in the slider base 71, and the first slider insert 72 can be slidably placed in the first mounting groove, and the bottom of the first slider insert 72 sequentially passes through the first mounting groove and the core-retracting plate 5 and is connected to the bottom plate 6. Two threaded holes penetrating to the bottom of the bottom plate 6 are provided on the bottom plate 6 at positions corresponding to each first slider insert 72, and each first slider insert 72 is fixed by locking screws screwed in from the two threaded holes; four inclined platforms 721 are respectively arranged around the top of the first slider insert 72, and second mounting grooves are provided on the slider base 71 at positions corresponding to each inclined platform 721. Each second slider insert 73 can be slidably placed in each second mounting groove, and each second slider insert 73 is provided with an inclined groove, and each second slider insert 73 can be slidably installed on the inclined platform 721 of the first slider insert 72 through the inclined groove;

[0035] A cavity is formed among the mold core, the B plate 4 and the slider base 71 for molding products; the slider base 71 is further provided with an undercut groove 711 below each second slider insert 73 for molding the undercut feature of the product;

[0036] Four second screw installation grooves with a preset second limit stroke are further arranged on the core-retracting plate 5. A second thimble screw 51 is installed in each second screw installation groove, and each second thimble screw 51 passes through the second screw installation groove and is fixedly arranged on the bottom plate 6. When the core-retracting plate 5 moves upward to the maximum stroke of the second limit stroke, the core-retracting plate 5 abuts against the second thimble screw 51, and the second thimble screw 51 plays a limiting role on the core-retracting plate 5;

[0037] On both sides of the reduced core plate 5 and the B plate 4, two buckle bases 9 are respectively arranged, providing a pulling force between the reduced core plate 5 and the B plate 4, and playing an auxiliary mold opening role through the buckle bases 9;

[0038] Six third stroke pull rods 61 are also arranged on the bottom plate 6. The tops of the six third stroke pull rods 61 penetrate through the bottom plate 6. The sprue plate 2, the A plate 3, the B plate 4 and the reduced core plate 5 are placed on the six third stroke pull rods 61 from top to bottom in sequence. A third stroke is provided between the A plate 3 and the B plate 4. When the B plate 4 moves upward to the maximum stroke of the third stroke, the B plate 4 abuts against the third stroke pull rod 61, and a pulling force is provided to the B plate 4 through the third stroke pull rod 61, playing an auxiliary mold opening role.

[0039] The working process and principle of the present invention are as follows:

[0040] When the product injection molding is completed, under the action of the mold opening control mechanism, the parting surface between the sprue plate 2 and the A plate 3 is first opened. The sprue plate 2 moves upward, and the second stroke pull rod 21 moves upward together with the sprue plate 2. The panel 1 is pushed upward by the sprue plate 2, and the first stroke pull rod 11 moves upward together with the panel 1. At this time, the first stroke pull rod 11 and the second stroke pull rod 21 have not reached the maximum stroke yet. Therefore, the A plate 3, the B plate 4, the reduced core plate 5 and the bottom plate 6 remain stationary;

[0041] When the parting surface between the sprue plate 2 and the A plate 3 is completely opened, the first stroke pull rod 11 has not reached the maximum stroke yet, and the second stroke pull rod 21 has reached the maximum stroke. The second stroke pull rod 21 abuts against the A plate 3, and the second stroke pull rod 21 provides a pulling force to the A plate 3. At this time, the parting surface between the panel 1 and the sprue plate 2 is opened under the action of the mold opening control mechanism, and the panel 1 moves upward. The first stroke pull rod 11 moves upward together with the panel 1. At this time, the first stroke pull rod 11 still has not reached the maximum stroke. Therefore, the sprue plate 2, the A plate 3, the B plate 4, the reduced core plate 5 and the bottom plate 6 remain stationary;

[0042] When the parting surface between the panel 1 and the sprue plate 2 is completely opened, the first stroke pull rod 11 has reached the maximum stroke. The first stroke pull rod 11 abuts against the A plate 3, and the first stroke pull rod 11 provides a pulling force to the A plate 3. At this time, the panel 1 abuts against the first set screw 12, and the panel 1 provides a pulling force to the sprue plate 2 through the first set screw 12;

[0043] The mold opening control mechanism continues to act on the panel 1, and the panel 1 continues to move upward, driving the sprue plate 2 connected to it by the first setscrew 12 to move upward together. The first stroke pull rod 11 moves upward with the panel 1, and the second stroke pull rod 21 moves upward with the sprue plate 2. The A plate 3 moves upward under the action of the pulling force provided by the first stroke pull rod 11 and the second stroke pull rod 21. At this time, the pulling force provided by the first stroke pull rod 11 and the second stroke pull rod 21 is not sufficient to complete the separation of the buckle base 9 and break the glue pull 8. The B plate 4 moves upward with the A plate 3 under the action of the glue pull 8, and the core shrinking plate 5 moves upward with the B plate 4 under the action of the buckle base 9. The bottom plate 6 remains stationary, causing the parting surface between the core shrinking plate 5 and the bottom plate 6 to open. At this time, the slider base 71 moves upward together with the core shrinking plate 5, and the second slider insert 73 moves upward under the action of the inclined platform 721 on the first slider insert 72 and also moves laterally inward towards the inside of the slider base 71; when the core shrinking plate 5 moves upward to abut against the second setscrew 51, the second slider insert 73 releases the restraint on the product undercut;

[0044] Under the action of the mold opening control mechanism, the panel 1 continues to move upward, the first stroke pull rod 11 and the sprue plate 2 move upward together with the panel 1, the second stroke pull rod 21 moves upward with the sprue plate 2, and the A plate 3 moves upward under the action of the pulling force provided by the first stroke pull rod 11 and the second stroke pull rod 21. At this time, the pulling force provided by the first stroke pull rod 11 and the second stroke pull rod 21 is not sufficient to break the glue pull 8. The B plate 4 moves upward with the A plate 3 under the action of the glue pull 8, and the core shrinking plate 5 remains stationary under the action of the second setscrew 51. At this time, the buckle base 9 is pulled open under the pulling force of the B plate 4, and then the restraint of the buckle base 9 on the B plate 4 and the core shrinking plate 5 is released. As the panel 1 continues to move upward, the B plate 4 moves upward with the A plate 3 under the action of the glue pull 8, and the parting surface between the B plate 4 and the core shrinking plate 5 opens, realizing the secondary core shrinking operation;

[0045] When the B plate 4 moves upward to abut against the third stroke pull rod 61, the B plate 4 remains stationary under the action of the third stroke pull rod 61, and the A plate 3 moves upward under the action of the pulling force provided by the first stroke pull rod 11 and the second stroke pull rod 21. At this time, the glue pull 8 is broken under the pulling force of the A plate 3, and then the restraint of the glue pull 8 on the A plate 3 and the B plate 4 is released. As the panel 1 continues to move upward, the A plate 3 moves upward under the action of the pulling force provided by the first stroke pull rod 11 and the second stroke pull rod 21, and the parting surface between the A plate 3 and the B plate 4 opens; when the parting surface between the A plate 3 and the B plate 4 is completely opened, the mold opening action is completed.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] 1. Through the design of the core-pulling mechanism, the present invention realizes secondary core shrinking. Compared with the prior art, the present invention solves the problem of difficult demolding of box-shaped products with undercuts, simplifies the mold structure, reduces the mold design and production costs, effectively avoids product damage, and ensures the normal production of products.

[0048] 2. In the preferred solution, the application of the glue pulling and the buckle base effectively plays a role in controlling the mold opening sequence.

[0049] 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 secondary shrinkage core structure for an injection mold, characterized in that It includes a panel, a sprue plate, a plate A, a plate B, a core-pulling plate and a bottom plate which are installed successively from top to bottom; the panel is used for mold clamping and placement of the locating ring; a glue injection runner is arranged between the sprue plate and the plate A for feeding the rubber material; several mold cores are placed on the plate B; a core-pulling mechanism matching the number of the several mold cores is arranged on the core-pulling plate for core-pulling demolding. Several rubber pulling members are arranged between the plate B and the plate A to provide a pulling force between the plate B and the plate A, which plays a role in controlling the mold opening sequence. Several buckle bases are arranged between the core-pulling plate and the plate B to provide a pulling force between the core-pulling plate and the plate B, which plays a role in controlling the mold opening sequence. Each core-pulling mechanism is composed of a slider base, a first slider insert and several second slider inserts; each slider base is arranged on the core-pulling plate corresponding to the position of the mold core; a first installation groove is arranged in the slider base, the first slider insert can be slidably placed in the first installation groove, and the bottom of the first slider insert is connected to the bottom plate; a bevel platform matching the number of the several second slider inserts is arranged at the top of the first slider insert, a second installation groove is arranged on the slider base corresponding to the position of each bevel platform, each second slider insert can be slidably placed in each second installation groove, and each second slider insert is provided with an inclined groove, and the first slider insert and the second slider insert are connected through the bevel platform and the inclined groove. Several first stroke pull rods are arranged on the panel; the bottoms of the several first stroke pull rods penetrate through the panel, and the sprue plate, the plate A, the plate B, the core-pulling plate and the bottom plate are successively placed on the several first stroke pull rods from top to bottom; during mold opening, the first stroke pull rods abut against the plate A to provide a pulling force to the plate A, which plays a role in assisting mold opening. Several second stroke pull rods are arranged on the sprue plate; the bottoms of the several second stroke pull rods penetrate through the sprue plate, and the plate A and the plate B are successively placed on the several second stroke pull rods from top to bottom; during mold opening, the second stroke pull rods abut against the plate A to provide a pulling force to the plate A, which plays a role in assisting mold opening.

2. The secondary shrink core structure of the injection mold according to claim 1, wherein Several first screw installation grooves are further arranged on the panel, a first stop screw is installed in each first screw installation groove, and each first stop screw penetrates through the first screw installation groove and is fixedly arranged on the sprue plate; during mold opening, the first stop screw abuts against the panel to play a role in limiting the panel through the first stop screw.

3. The secondary shrink core structure of the injection mold according to claim 1, characterized in that, Several second screw installation grooves are further arranged on the core-pulling plate, a second stop screw is installed in each second screw installation groove, and each second stop screw penetrates through the second screw installation groove and is fixedly arranged on the bottom plate; during mold opening, the core-pulling plate abuts against the second stop screw to play a role in limiting the core-pulling plate through the second stop screw.

4. The secondary shrink core structure of the injection mold according to claim 1, characterized in that, A number of third stroke tie rods are arranged on the bottom plate, and the tops of the number of third stroke tie rods penetrate through the bottom plate. The sprue plate, A plate, B plate, and shrink core plate are sequentially placed on the number of third stroke tie rods from top to bottom. When the mold is opened, the B plate abuts against the third stroke tie rod, and a pulling force is provided to the B plate through the third stroke tie rod, playing an auxiliary role in mold opening.

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