Die structure with self-shrinking loose core

Abstract

A mold structure with a self-shrinking loose core comprises a movable mold and a fixed mold which are arranged up and down, the fixed mold is provided with a cavity, the rear portion of the cavity is a forming area, the front portion of the cavity is provided with a loose core seat, and a loose core block capable of moving in the front-back direction, a left loose core and a right loose core are arranged in the loose core seat and located on the left side and the right side of the loose core block respectively. The left loose core and the right loose core are in sliding fit along the left-right direction relative to the loose core seat; the movable mold is provided with a guide table extending to the front portion of the cavity, the guide table is provided with a third guide rail gradually inclining forwards from top to bottom, and the front end of the core pulling block is slidably connected to the third guide rail. According to the scheme, by designing the movable left loose core and the movable right loose core, rapid demolding of the forming parts of the left loose core and the right loose core relative to the clamping hook structure during demolding is achieved, and the situation that in the prior art, when two fixed forming parts are separated from the clamping hook structure, the clamping hook structure is prone to being pulled apart is effectively improved.

Description

Technical Field

[0001] This invention relates to the technical field of injection molds, and more specifically to a mold structure with self-shrinking core pulling. Background Technology

[0002] Injection molds are key tools for mass production of plastic or metal products, typically consisting of a fixed mold, a moving mold, and a gating system. The fixed and moving molds enclose a cavity, the shape of which corresponds to the product form. During processing, molten raw material is injected into the cavity under high pressure, cooled and solidified, and then demolded to obtain a finished product with stable quality.

[0003] For thin-walled products, due to their thin walls, the structural strength is often low after cooling and molding within the mold cavity, thus requiring core pulling to assist in demolding. For example... Figure 11 As shown, some thin-walled products require two spaced hook structures to be machined on the sidewalls. The hooks of the two hook structures are opposite and symmetrical. Current solutions typically involve designing two forming parts on the core puller with shapes corresponding to the hook structures. After the product cools and solidifies, the two forming parts are disengaged from the hook structures by pushing the core puller upwards or downwards. However, because the hook structures are also thin-walled, the tight fit between the forming parts and the hook structures creates significant demolding resistance during the upward or downward movement of the core puller. This frequently results in the hook structures being torn off by the core puller, severely restricting the product yield. Summary of the Invention

[0004] The purpose of this invention is to solve the problem in the prior art that when processing thin-walled products with hook structures, the core-pulling molding part and the hook structure are closely fitted, resulting in large demolding resistance. This often leads to the hook structure being torn off by the core-pulling process, which seriously restricts the product qualification rate.

[0005] To solve the above problems, the present invention provides a mold structure with self-shrinking core pulling, including a moving mold and a fixed mold arranged vertically. The fixed mold has a cavity facing the moving mold. The rear part of the cavity is a forming area and the front part is a core pulling seat. The fixed mold has a push rod for pushing the core pulling seat to rise and fall. The core pulling seat has a core pulling block that can move in the front-back direction, and a left core pulling and a right core pulling respectively located on the left and right sides of the core pulling block. The left side of the rear part of the core pulling block has a first guide rail and the right side has a second guide rail. The first guide rail is inclined from front to back and to the right, and the second guide rail is inclined from front to back and to the left. The left core pulling and the right core pulling are slidably connected to the first guide rail and the second guide rail respectively, and the left core pulling and the right core pulling slide in the left-right direction relative to the core pulling seat. The left side of the left core pulling facing the forming area has a forming part, and the right side of the right core pulling facing the forming area has a forming part. The movable mold is provided with a guide table extending to the front part of the cavity, and the guide table is provided with a third guide rail gradually inclined forward from top to bottom, and the front end of the core-pulling block is slidably connected to the third guide rail; When demolding, as the movable mold moves upward away from the fixed mold, the guide table moves upward so that the core-pulling block is driven by the third guide rail to move forward, and the left core-pulling block is driven by the first guide rail to move right, and the right core-pulling block is driven by the second guide rail to move left.

[0006] In the above scheme, the forming area of the cavity is the forming position of the product, the rear side of the core-pulling seat corresponds to the outer side wall of the product, and the forming parts of the left and right core-pulling blocks on the core-pulling seat realize the forming processing of the two hook structures of the outer side wall of the product; when demolding, as the movable mold moves upward, the core-pulling block drives the left and right core-pulling blocks to move close to each other, so that the forming parts of the left and right core-pulling blocks can directly separate from the hook structure by moving a small distance, and then the core-pulling seat is lifted by the push rod, and the product can be taken out. Compared with the prior art, the above scheme realizes the rapid demolding of the forming parts of the left and right core-pulling blocks relative to the hook structure by designing the movable left and right core-pulling blocks, effectively improves the situation that the two fixed forming parts in the prior art are easily torn off when separating from the hook structure, and has good practicability.

[0007] In an improved scheme, the core-pulling seat is provided with a guide hole penetrating in the front-rear direction, the front part of the guide hole is provided with a limiting convex ring, the front part of the core-pulling block is slidably inserted into the inner hole of the limiting convex ring and the rear side corresponds to the rear end of the guide hole, the left and right core-pulling blocks are located in the rear part of the guide hole, and the rear sides of the left and right core-pulling blocks are flush with the rear side of the core-pulling block, and the front ends of the left and right core-pulling blocks are slidably abutted to the rear side of the limiting convex ring, so as to realize the guidance of the front-rear direction of the core-pulling block through the inner hole of the limiting convex ring, and the movement direction of the left and right core-pulling blocks relative to the core-pulling seat is limited to the left-right direction through the sliding abutment of the limiting convex ring to the front ends of the left and right core-pulling blocks, so as to realize the compact structure and stable operation.

[0008] In an improved scheme, the rear end of the guide hole is rectangular, and the lower side edge of the rear end of the guide hole is provided with a scraping blade, when the core-pulling block drives the left and right core-pulling blocks to move close to each other, the front sides of the left and right core-pulling blocks will extrude the outer side wall of the product, so that the corresponding position of the outer side wall of the product forms a excess material protrusion, therefore, by setting the scraping blade on the lower side edge of the front end of the guide hole, when the core-pulling seat is lifted by the push rod in the last stage, the scraping blade can scrape the excess material protrusion, so as to ensure the flatness of the outer side wall of the product.

[0009] In an improved scheme, the rear part of the lower side wall of the guide hole is provided with a downward penetrating waste discharge hole, so that the excess material scraped by the scraping blade can be discharged from the waste discharge hole and fall back into the cavity of the fixed mold, avoiding the accumulation of excess material in the guide hole.

[0010] In an improved scheme, the left side of the rear part of the core-pulling block is inclined rightward from front to back, and the right side is inclined leftward from front to back, the first guide rail is arranged in parallel to the left side of the rear part of the core-pulling block, and the second guide rail is arranged in parallel to the right side of the rear part of the core-pulling block.

[0011] In an improved scheme, a guide groove extending in the vertical direction is arranged on the front side of the core-pulling base, and the guide table is slidingly fitted into the guide groove. Since the guide table will be subjected to a larger deflection torque when the third guide rail drives the core-pulling block, the guide groove is arranged on the front side of the core-pulling base to guide the guide table through the guide groove, thereby improving the stability of the guide table during movement.

[0012] In an improved scheme, the mold clamping device further comprises a lifting plate and a lifting driving member, the lifting driving member is arranged on one side of the fixed mold in the vertical direction, the lifting plate is arranged below the fixed mold and is driven to lift by the lifting driving member, the push rod is at least two, the lower end of the push rod is connected with the lifting plate, and the upper end of the push rod is connected with the core-pulling base, so that the lifting driving member drives the lifting plate to drive the plurality of push rods to lift, thereby realizing more stable lifting drive of the core-pulling base. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 It is a whole schematic view of a mold structure with self-shrinking core-pulling; Figure 2 It is a front view schematic view of a mold structure with self-shrinking core-pulling; Figure 3 It is a sectional view schematic view along Figure 2 A-A sectional line; Figure 4 It is a sectional view schematic view along Figure 3 B-B sectional line; Figure 5 It is a partial enlarged schematic view of C area; Figure 3 Figure 6 It is a schematic view of a mold structure with self-shrinking core-pulling after the fixed mold is hidden; Figure 7 It is a schematic view of a mold structure with self-shrinking core-pulling after the fixed mold and the movable mold are hidden; Figure 8 It is a schematic view of the rear side of the core-pulling base of a mold structure with self-shrinking core-pulling; Figure 9 It is a schematic view of the core-pulling block, the left core-pulling block and the right core-pulling block of a mold structure with self-shrinking core-pulling; Figure 10 It is a schematic view of the core-pulling block of a mold structure with self-shrinking core-pulling; ​Figure 11 schematic diagram of a product.

[0014] Reference signs, 1, moving die; 11, guide table; 12, third guide rail; 2, fixed die; 21, cavity; 21a, forming area; 3, push rod; 4, core-pulling base; 41, guide hole; 42, limiting convex ring; 43, scraping blade; 44, waste hole; 45, guide groove; 5, core-pulling block; 51, first guide rail; 52, second guide rail; 61, left core-pulling; 62, right core-pulling; 63, forming part; 7, lifting driving part; 71, lifting plate; 8, hook structure. DETAILED DESCRIPTION

[0015] It should be understood by those skilled in the art that the following embodiments are only used to explain the technical principles of the embodiments of the present application, and are not intended to limit the protection scope of the embodiments of the present application. Those skilled in the art can make adjustments as needed in order to adapt to specific application occasions.

[0016] In the description of the following embodiments, it should be noted that unless otherwise explicitly specified and limited, the terms "connected", "connected" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0017] In the embodiments of the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature. The first and second features can be in direct contact, or the first and second features can be in indirect contact through an intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature can be that the first feature is directly above or obliquely above the second feature, or it only means that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature can be that the first feature is directly below or obliquely below the second feature, or it only means that the horizontal height of the first feature is less than that of the second feature.

[0018] The present application will be further described in detail below in combination with the drawings and specific embodiments.

[0019] Please refer to Figures 1-11The embodiment of the present application provides a mold structure with self retracting cores, which comprises a movable mold 1 and a fixed mold 2 arranged in a top-down mode, the fixed mold 2 is provided with a cavity 21 facing the movable mold 1, the rear part of the cavity 21 is a forming area 21a and the front part is provided with a core-pulling base 4, the fixed mold 2 is provided with a push rod 3 used for pushing the core-pulling base 4 to ascend and descend, the core-pulling base 4 is provided with a core-pulling block 5 which can move in the front-rear direction, and a left core-pulling block 61 and a right core-pulling block 62 which are respectively arranged on the left side and the right side of the core-pulling block 5, the left side of the rear part of the core-pulling block 5 is provided with a first guide rail 51 and the right side is provided with a second guide rail 52, the first guide rail 51 is arranged in a right tilt mode from front to back, the second guide rail 52 is arranged in a left tilt mode from front to back, the left core-pulling block 61 and the right core-pulling block 62 are respectively slidably connected to the first guide rail 51 and the second guide rail 52, and the left core-pulling block 61 and the right core-pulling block 62 are slidably matched with the core-pulling base 4 in the left-right direction, the left core-pulling block 61 is provided with a forming part 63 on the left side of one end of the forming area 21a, and the right core-pulling block 62 is provided with a forming part 63 on the right side of one end of the forming area 21a. The movable mold 1 is provided with a guide table 11 extending to the front part of the cavity 21, the guide table 11 is provided with a third guide rail 12 which is gradually tilted forward from top to bottom, and the front end of the core-pulling block 5 is slidably connected to the third guide rail 12. When demolding, with the movable mold 1 moving upward and away from the fixed mold 2, the guide table 11 moves upward, so that the core-pulling block 5 is driven by the third guide rail 12 to move forward, then the left core-pulling block 61 is driven by the first guide rail 51 to move right, and the right core-pulling block 62 is driven by the second guide rail 52 to move left.

[0020] In the above scheme, the forming area 21a of the cavity 21 is the forming position of the product, the rear side of the core-pulling base 4 corresponds to the outer side wall of the product, and the forming parts 63 of the left core-pulling block 61 and the right core-pulling block 62 on the core-pulling base 4 are used for forming the two hook structures 8 of the outer side wall of the product. Figure 3 As shown, since the forming parts 63 of the left core-pulling block 61 and the right core-pulling block 62 correspond to the hook structures 8, the forming part 63 of the left core-pulling block 61 is a groove arranged on the left side of the rear end of the left core-pulling block 61, and the forming part 63 of the right core-pulling block 62 is a groove arranged on the right side of the rear end of the right core-pulling block 62. It should be understood that the forming part 63 can also adopt other shapes according to needs, and the design does not limit this.

[0021] When demolding, as the movable mold 1 moves upward, the core pulling block 5 drives the left core pulling block 61 and the right core pulling block 62 to approach each other, so that the forming portions 63 of the left core pulling block 61 and the right core pulling block 62 can directly separate from the hook structure 8 by moving a small distance, and then the core pulling block 4 is lifted by the push rod 3, so that the product can be taken out. Compared with the prior art, the above scheme realizes the quick demolding of the forming portions 63 of the left core pulling block 61 and the right core pulling block 62 relative to the hook structure 8 during demolding by designing the movable left core pulling block 61 and the right core pulling block 62, effectively improves the situation that the two fixed forming portions 63 in the prior art are easily torn off from the hook structure 8, and has good practicability.

[0022] In combination Figure 3 As shown in the embodiment, the core pulling block 5 is provided with a guide hole 41 penetrating in the front-rear direction, the guide hole 41 is located in the middle of the core pulling block 4, the front part of the guide hole 41 is provided with a limiting convex ring 42, the front part of the core pulling block 5 is slidingly inserted into the inner hole of the limiting convex ring 42 and the rear side corresponds to the rear end of the guide hole 41, the left core pulling block 61 and the right core pulling block 62 are located in the rear part of the guide hole 41, and the rear sides of the left core pulling block 61 and the right core pulling block 62 are flush with the rear side of the core pulling block 5, the front ends of the left core pulling block 61 and the right core pulling block 62 are slidingly abutted to the rear side of the limiting convex ring 42, so as to realize the front-rear direction guidance of the core pulling block 5 through the inner hole of the limiting convex ring 42, and the sliding abutment of the front ends of the left core pulling block 61 and the right core pulling block 62 by the limiting convex ring 42 makes the left core pulling block 61 and the right core pulling block 62 unable to move forward and backward, but only able to move left and right relative to the core pulling block 4, so that the structure is compact and the operation is stable. In addition, the rear sides of the left core pulling block 61 and the right core pulling block 62 are flush with the rear side of the core pulling block 5, which can make the product outer side wall in a flat state during forming; if the product outer side wall does not need to be in a flat state, the rear sides of the left core pulling block 61 and the right core pulling block 62 do not need to be flush with the rear side of the core pulling block 5, and this way also belongs to the protection scope of the embodiment.

[0023] In combination Figure 4 And Figure 8 As an optimization scheme of the embodiment, the rear end of the guide hole 41 is rectangular, and the lower side of the rear end of the guide hole 41 is provided with a scraping blade 43, which is a relatively sharp horizontal edge and has a higher hardness than the core pulling block 5. After the core pulling block 5 drives the left core pulling block 61 and the right core pulling block 62 to approach each other, the rear sides of the left core pulling block 61 and the right core pulling block 62 will extrude the product outer side wall, causing the corresponding position of the product outer side wall to form a excess material protrusion. Therefore, by providing the scraping blade 43 on the lower side of the rear end of the guide hole 41, when the core pulling block 4 is lifted by the push rod 3 in the last stage, the scraping blade 43 can scrape the excess material protrusion, ensuring the flatness of the product outer side wall.

[0024] Further, as Figure 4As shown, the rear part of the lower side wall of the guide hole 41 is provided with a waste hole 44 penetrating downward to the bottom surface of the core-pulling base 4, so that the excess material scraped off by the scraping blade 43 can be discharged from the waste hole 44 and fall back into the cavity of the fixed mold, avoiding the accumulation of excess material in the guide hole 41.

[0025] As shown in the drawings, Figure 5 In the present embodiment, the left side surface of the rear part of the core-pulling block 5 is inclined to the right from front to back, and the right side surface is inclined to the left from front to back, so that the rear part of the core-pulling block 5 forms a shape similar to a trapezoid or a cone, the first guide rail 51 is arranged in parallel on the left side surface of the rear part of the core-pulling block 5, and the second guide rail 52 is arranged in parallel on the right side surface of the rear part of the core-pulling block 5. In addition, the first guide rail 51 and the second guide rail 52 are both dovetail guide rails, so as to ensure more stable sliding fit between the first guide rail 51 and the left core-pulling block 61, and between the second guide rail 52 and the right core-pulling block 62.

[0026] As shown in the drawings, Figure 7 As an improvement of the present embodiment, the front side of the core-pulling base 4 is provided with a vertically extending guide groove 45, and the guide table 11 is slidingly fitted into the guide groove 45. Since the guide table 11 will be subjected to a large deflection torque when the third guide rail 12 drives the core-pulling block 5, the guide groove 45 is arranged on the front side of the core-pulling base 4 to guide the guide table 11, thereby improving the stability of the guide table 11 during movement.

[0027] As another improvement of the present embodiment, a lifting plate 71 and a lifting driving member 7 are further included, the lifting driving member 7 is preferably an oil cylinder and is arranged vertically on one side of the fixed mold 2, the lifting plate 71 is located below the fixed mold 2 and is driven to lift by the lifting driving member 7, the push rod 3 is at least two and the lower end of the push rod 3 is connected with the lifting plate 71, and the upper end of the push rod 3 is connected with the core-pulling base 4, so that the lifting driving member 7 drives the lifting plate 71 to drive the plurality of push rods 3 to lift, thereby realizing more stable lifting drive of the core-pulling base 4.

[0028] It should be noted that in the description of the present application, the terms indicating the direction or positional relationship of "in", "out" and the like are based on the direction or positional relationship shown in the drawings, which is only for the convenience of description, and does not indicate or imply that the device or member must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application; all directional indications (such as up, down, left, right, front, back, inner, outer) are only used to explain the relative positional relationship, movement condition, etc. between the components in a certain specific posture, and if the specific posture changes, the directional indications will also change accordingly.

[0029] In the description of the application, the description of the terms "one embodiment", "some embodiments", "in this embodiment", "specific example", or "some examples" and the like means that the specific features, mechanisms, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the application. In the description, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, mechanisms, materials or characteristics described can be combined in any suitable manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine the different embodiments or examples described in the specification and the features of the different embodiments or examples without contradiction.

[0030] The above description is merely a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A mold structure having a self- retracting core, characterized by, The die set comprises an upper and lower movable die and a fixed die, the fixed die is provided with a cavity towards the movable die, the rear part of the cavity is a forming area and the front part is provided with a core-pulling base, the fixed die is provided with a push rod for pushing the core-pulling base to move up and down, the core-pulling base is provided with a core-pulling block which can move in the front-rear direction, and a left core-pulling and a right core-pulling are respectively arranged on the left side and the right side of the core-pulling block, the left side of the rear part of the core-pulling block is provided with a first guide rail which is inclined to the right from front to back, the right side of the rear part of the core-pulling block is provided with a second guide rail which is inclined to the left from front to back, the left core-pulling and the right core-pulling are respectively connected to the first guide rail and the second guide rail by sliding, and the left core-pulling and the right core-pulling are slidably matched with the core-pulling base in the left-right direction, the left side of one end of the left core-pulling towards the forming area is provided with a forming part, and the right side of one end of the right core-pulling towards the forming area is provided with a forming part. The movable die is provided with a guide table extending to the front part of the cavity, the guide table is provided with a third guide rail which is gradually inclined forward from top to bottom, and the front end of the core-pulling block is connected to the third guide rail by sliding. When the mold is demolded, as the movable die moves upward away from the fixed die, the guide table moves upward, so that the core-pulling block is driven by the third guide rail to move forward, the left core-pulling is driven by the first guide rail to move right, and the right core-pulling is driven by the second guide rail to move left.

2. The mold structure having self- retracting core according to claim 1, wherein, The core-pulling base is provided with a guide hole which penetrates in the front-rear direction, the front part of the guide hole is provided with a limiting convex ring, the front part of the core-pulling block is inserted into the inner hole of the limiting convex ring and the rear side corresponds to the rear end of the guide hole, the left core-pulling and the right core-pulling are both located in the rear part of the guide hole, and the rear sides of the left core-pulling and the right core-pulling are flush with the rear side of the core-pulling block, and the front ends of the left core-pulling and the right core-pulling are slidably abutted to the rear side of the limiting convex ring.

3. The mold structure having self- retracting core according to claim 2, wherein, The rear end of the guide hole is rectangular, and the lower side edge of the rear end of the guide hole is provided with a scraping blade.

4. The mold structure having self- retracting core according to claim 3, wherein The rear part of the lower side wall of the guide hole is provided with a waste discharge hole which penetrates downward.

5. A mould structure with self- retracting cores according to any one of claims 2-4, characterised in that The left side surface of the rear part of the core-pulling block is inclined to the right from front to back, and the right side surface of the rear part of the core-pulling block is inclined to the left from front to back, the first guide rail is arranged in parallel on the left side surface of the rear part of the core-pulling block, and the second guide rail is arranged in parallel on the right side surface of the rear part of the core-pulling block.

6. The mold structure having self- retracting core according to claim 1, wherein, The front side of the core-pulling base is provided with a guide groove which extends in the vertical direction, and the guide table is slidably matched with the guide groove.

7. A mold structure having self- retracting cores according to claim 1 or 6, characterized in that, Further comprising a lifting plate and a lifting driving member, the lifting driving member is arranged in the vertical direction on one side of the fixed die, the lifting plate is located below the fixed die and is driven by the lifting driving member to move up and down, the push rod is at least two, and the lower end of the push rod is connected with the lifting plate, and the upper end of the push rod is connected with the core-pulling base.

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