An injection mold

Abstract

The present application relates to injection molding technology field, specifically to a kind of injection mold, comprising: front mould plate, front mould core, back mould plate, back mould core and back mould row seat, material removal plate, upper fixed plate, ejector pin plate, sprue pin, respectively connect the ejector pin plate and the back mould core, the sprue pin is equipped with sprue demoulding part;The upper fixed plate is provided with main runner, the material removal plate, the front mould plate, the front mould core and the back mould row seat are provided with shunt, the back mould core is provided with sprue, the main runner, the shunt and the sprue three intercommunication settings, the sprue is divided into needle part, real sprue part and false sprue part, the real sprue part and the false sprue part are symmetrically balanced relative to the needle part setting.Benefiting from sprue demoulding part, reduce the contact area between sprue pin and material head, not prone to the situation of bouncing, since the symmetrically balanced setting between real sprue part and false sprue part, material head gravity balance, not prone to the situation of bouncing.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of injection molding, and particularly relates to an injection mold. BACKGROUND

[0002] In the injection molding production process, a latent gate is widely used because it can automatically cut off the gate. The principle of ejection is to forcibly eject the mold cavity by making the formed material head of the latent gate yield under the action of the ejector pin.

[0003] Currently, the material head is mainly cleaned by using a nozzle ejector pin to eject the material head, relying on two ways of automatic falling after ejection and clamping by a mechanical hand after ejection. The automatic falling way has the problem that the material head is bounced after being ejected due to elastic deformation. In addition, the mold cavity structure is complex, and the material head may be stuck in the mold cavity. If it is not cleaned in time before the mold is closed, a mold pressing accident is likely to occur, which may damage the precise and expensive mold cavity. Therefore, with the improvement of industrial automation, the use of a mechanical hand to position and clamp in a fixed station has become the mainstream scheme. This scheme requires that the material head must be stably kept at a preset position after being ejected, but it faces a core contradiction: if the wrapping force of the material head on the ejector pin is too small, the material head is easy to fall; if the wrapping force is too large, the mechanical hand is difficult to clamp.

[0004] Patent No. CN218660209U is an injection material head, which comprises a material head body, a push rod is formed on the body, and a plurality of spaced apart baffles are arranged on the end of the push rod, which enclose a pin cavity. The core purpose of this design is that the pin is inserted into the cavity to push the material head, and is positioned by the cooperation of the baffles and the pin. At the same time, the gap between the baffles reduces the wrapping force of the material head on the pin after cooling, thereby facilitating subsequent grabbing by the mechanical hand. However, there are the following problems. First, although the push rod reduces the wrapping force of the material head on the pin by designing a cavity at the baffle, the uniform distribution of the cavity excessively weakens the guiding and positioning effect of the pin on the material head, so that the restraining force is excessively weakened. Second, this design does not consider the problem of the center of gravity balance of the material head, and the center of gravity does not coincide with the pin.

[0005] Based on the above two problems, the following situations may occur. First, in the process of separating from the mold cavity, the part of the material head close to the product cavity will accumulate elastic potential energy. When the material head has not completely left the mold cavity, if the force applied by the mold to the material head is greater than the restraining force between the pin and the material head, a certain separation inclination will occur between the material head and the pin. After the material head completely leaves the mold cavity, the force generated by the release of the elastic potential energy will be greater than the restraining force between the pin and the material head, and the material head will be bounced.

[0006] Second, after the material head leaves the mold cavity, if the material head is still on the ejector pin, the torque generated by the unbalanced center of gravity will cause the softer material head to deviate and deform itself under the condition of greater constraint force, and will cause the softer material head to deviate and rotate relative to the ejector pin under the condition of smaller constraint force, thereby affecting the accuracy of the mechanical hand clamping. SUMMARY

[0007] The purpose of the embodiments of the present application is to provide an injection mold to solve the technical problems existing in the prior art.

[0008] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is to provide an injection mold, comprising:

[0009] The front mold plate is provided with a front mold core;

[0010] The rear mold plate is provided with a rear mold core and a rear mold row seat;

[0011] The stripper plate is arranged on the front side of the front mold plate

[0012] The upper fixed plate is arranged on the front side of the stripper plate;

[0013] The ejector pin plate is arranged on the rear side of the rear mold plate;

[0014] The gate pin is connected to the ejector pin plate and the rear mold core, respectively, and the end of the rear mold core is tapered towards the front mold plate to form a gate demolding part;

[0015] The upper fixed plate is provided with a main flow channel, the stripper plate, the front mold plate, the front mold core and the rear mold row seat are provided with a branch flow channel, the rear mold core is provided with a gate, the main flow channel, the branch flow channel and the gate are communicated, the gate is divided into a needle connecting part, a real gate part and a false gate part, the needle connecting part communicates with the chamber where the gate pin is located, the real gate part communicates with the product cavity, and the real gate part and the false gate part are symmetrically and balancedly arranged relative to the needle connecting part.

[0016] Optionally, the end of the gate pin inserted into the rear mold core also has an anti-rotation limiting part, the anti-rotation limiting part is located on the side of the gate demolding part away from the gate, the circumferential outer wall of the anti-rotation limiting part is used to connect with the material head, and the non-circular arc outer wall of the anti-rotation limiting part is connected with the material head.

[0017] Optionally, the circumferential outer wall of the anti-rotation limiting part has a material connecting surface and a cavity abutting surface, the material connecting surface is used to connect with the material head, and the cavity abutting surface is used to abut against the inner wall of the chamber where the gate pin is located.

[0018] Optionally, an angle between the real gate and the connecting pin is larger than an angle between the false gate and the connecting pin.

[0019] Optionally, a length of the real gate along the gate pin axial direction is consistent with a length of the false gate along the gate pin axial direction.

[0020] Optionally, the real gate is tapered towards the connecting pin.

[0021] Optionally, the gate further comprises a supplementary connecting cavity part connecting the real gate and the product cavity, and an end of the supplementary connecting cavity part away from the real gate extends towards the front mold plate.

[0022] Optionally, the ejector plate is connected with a gate inclined ejector, the gate inclined ejector is slidably arranged in the back mold core, and an outer wall of the gate inclined ejector forms part of an inner wall of the product cavity and the supplementary connecting cavity part.

[0023] Optionally, the back mold core comprises a back mold core and a back mold insert, the back mold core is arranged for the gate and is fixed on the back mold plate, the back mold insert is fixedly arranged in the back mold core and is used for forming a rib cavity in the back mold core, the back mold insert is provided with an ejector guide hole, and the ejector plate is connected with an insert ejector, the insert ejector is slidably arranged in the ejector guide hole.

[0024] Optionally, a side of the ejector plate away from the back mold plate is provided with a lower fixed plate, the lower fixed plate is fixedly arranged, the lower fixed plate is provided with a hole-forming insert, the hole-forming insert is slidably arranged in the back mold core, the ejector plate is provided with a hole-removing guide sleeve, the hole-removing guide sleeve is slidably arranged on the hole-forming insert, and the hole-removing guide sleeve is slidably arranged in the back mold core.

[0025] The injection mold provided by the application has the following beneficial effects:

[0026] Compared with the prior art, the application solves the following problems: first, by means of the gate demolding part, the contact area between the gate pin and the material head is reduced, but the restraint force of the gate pin on the material head is not excessively weakened, so that the material head is not easy to tilt or deviate uncontrollably when not completely separated from the mold cavity, so that the material head is not easy to fly at the moment of subsequent separation, and the tapered gate demolding part converts the force generated by the cooling and shrinkage of the material head into the tendency of the material head to be released along the gate pin axial direction, thereby ensuring the convenience of the mechanical hand clamping; second, due to the symmetrical and balanced arrangement between the real gate and the false gate, the center of gravity of the material head is balanced, so that the material head is not easy to deviate or rotate, and is not easy to affect the clamping accuracy of the subsequent mechanical hand, and is not easy to fly the material head at the moment of separation from the mold cavity. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0028] Figure 1 The three-dimensional structure of the present application is shown in the embodiment Figure 1 ;

[0029] Figure 2 The cross-sectional view of the present application is shown in the embodiment along A-A Figure 1 ; Figure 2

[0030] Figure 3 The flow channel structure of the present application is shown in the embodiment Figure 3 ;

[0031] Figure 4 The force on the material head of the present application is shown in the embodiment Figure 4 ;

[0032] Figure 5 The three-dimensional structure of the present application is shown in the embodiment of the gate pin Figure 5 ;

[0033] Figure 6 The cooperation of the back core and the back mold plate of the present application is shown in the embodiment Figure 6 ;

[0034] Figure 7 The cooperation of the hole extraction guide sleeve and the hole forming insert of the present application is shown in the embodiment Figure 7 ;

[0035] Figure 8 The partial enlargement of the present application is shown in the embodiment Figure 7 A place Figure 8 .

[0036] In the drawings, various reference signs represent:

[0037] ​1, front template; 11, front mold core; 2, rear template; 21, rear mold core; 211, rear mold core; 212, rear mold insert rod; 2121, ejector pin guide hole; 213, rib cavity; 214, insert rod ejector pin; 22, rear mold position seat; 3, stripping plate; 4, upper fixed plate; 5, ejector plate; 51, gate inclined top; 52, stripping hole guide sleeve; 6, gate pin; 61, gate stripping part; 62, anti-rotation limiting part; 621, material connecting surface; 622, cavity adhering surface; 7, main runner; 71, sub-runner; 72, gate; 721, pin connecting part; 722, real gate part; 723, false gate part; 724, supplementary cavity connecting part; 8, lower fixed plate; 81, hole forming insert pin. DETAILED DESCRIPTION

[0038] In order to make the technical problems, technical solutions and beneficial effects of the present application clearer, the present application will be further described in detail below in conjunction with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application.

[0039] It should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0040] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the present application and simplify the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0041] The embodiments of the present application will be described below in conjunction with Figures 1 to 8 The injection mold provided by the embodiments of the present application,

[0042] As Figures 1 to 3As shown, specifically, the injection mold includes a front mold plate 1, a rear mold plate 2, a stripping plate 3, an upper fixed plate 4, a ejector plate 5, and a sprue pin 6. The front mold plate 1 is provided with a front mold core 11, which is fixedly arranged on the side of the front mold plate 1 close to the rear mold plate 2, that is, the lower side of the front mold plate 1 in the figure. The rear mold plate 2 is provided with a rear mold core 21 and a rear mold core seat 22. The rear mold core 21 is fixedly arranged, and the rear mold core seat 22 is slidingly arranged, which can be brought together or away from the front mold core 11 and the rear mold core 21. The stripping plate 3 is arranged on the front side of the front mold plate 1, which is the side of the front mold plate 1 away from the rear mold plate 2, and the stripping plate 3 can be close to or away from the front mold plate 1. The upper fixed plate 4 is arranged on the front side of the stripping plate 3, which is the side of the stripping plate 3 away from the front mold plate 1, and the upper fixed plate 4 can also be close to or away from the stripping plate 3. The ejector plate 5 is located on the rear side of the rear mold plate 2, which is the side of the rear mold plate 2 away from the front mold plate 1, and the ejector plate 5 can be close to or away from the rear mold plate 2. The sprue pin 6 is connected to the ejector plate 5 and the rear mold core 21 respectively, and the sprue pin 6 is inserted into the tapered end of the rear mold core 21, which narrows towards the front mold plate 1 to form a sprue stripping part 61. The above forms the entity structure of the mold.

[0043] The mold also involves a gating system. Specifically, the upper fixed plate 4 is provided with a main runner 7, the stripping plate 3, the front mold plate 1, the front mold core 11, and the rear mold core seat 22 are provided with a branch runner 71, the rear mold core 21 is provided with a sprue 72, the main runner 7 communicates with the two side surfaces of the upper fixed plate 4 close to and away from the stripping plate 3, one end of the branch runner 71 communicates with the side surface of the stripping plate 3 close to the upper fixed plate 4, the other end communicates with the side surface of the rear mold core seat 22 abutting against the rear mold core 21, one end of the sprue 72 communicates with the side surface of the rear mold core 21 abutting against the rear mold core seat 22, and the other end communicates with the product cavity, so that the main runner 7, the branch runner 71, and the sprue 72 are communicated.

[0044] In this embodiment, the latent sprue 72 is used, which is mainly used in multi-cavity molds, that is, one mold can process multiple products, so the branch runner 71 is provided. The main runner 7, the branch runner 71, and the sprue 72 are communicated to form a complete flow path from the injection molding machine to the product cavity, ensuring that the melt can be continuously and stably filled into every corner of the product cavity.

[0045] Meanwhile, the sprue 72 is also divided into a connecting needle part 721, a real sprue part 722 and a false sprue part 723. The connecting needle part 721 communicates with the cavity where the sprue pin 6 is located. The real sprue part 722 communicates with the product cavity. The real sprue part 722 and the false sprue part 723 are symmetrically and balancedly arranged relative to the connecting needle part 721. Among them, the symmetrically and balancedly arranged is not that the geometry of the material head between the real sprue part 722 and the false sprue part 723 is completely the same, but that the material head is located at two parts of the real sprue part 722 and the false sprue part 723. The combined gravity center of the two parts is located at the connecting needle part 721, so as to balance the gravity center of the material head.

[0046] It should be noted that, since the part of the material head located at the main runner 7 and the branch runner 71 is separated from the part located at the sprue 72 when the mold is opened, the part of the material head located at the main runner 7 and the branch runner 71 is in a mesh structure, and the part of the material head located at the main runner 7 and the branch runner 71 does not yield during the mold opening process. Therefore, the material head does not pop and deviate, and the material head mentioned in the present application is only the part located in the sprue 72. In order to facilitate description, the material head is directly used for expression.

[0047] Considering that the material head needs to stably move along the demolding path during the ejection process of the sprue pin 6, in order to avoid the material head from popping due to uneven force at the moment of separation, the sprue pin 6 has a sprue demolding part 61 in the present embodiment. Therefore, no matter which circumferential direction the material head deviates to during the ejection process, the material head will be subjected to a reverse force of the taper surface, so as to ensure that the material head stably moves along the demolding path. The ejected material head will shrink to the center during the natural cooling process. Since the contact surface between the material head and the sprue demolding part 61 is tapered, the shrinkage force generated by the cooling deformation of the contact surface will be converted into a displacement component along the axis direction of the sprue pin 6.

[0048] Among them, in the present embodiment, the taper of the sprue demolding part 61 is 15°. The angle value is the optimal solution based on the comprehensive consideration of the friction characteristics, shrinkage behavior and ejection mechanics of various plastics. It is especially suitable for commonly used engineering plastics such as ABS and PC. If the taper of the sprue demolding part 61 is too large, the wrapping force will decrease due to the reduction of the contact area between the sprue demolding part 61 and the material head. If the taper is too small, the wrapping force will increase due to the increase of the contact area between the sprue demolding part 61 and the material head, which cannot make the material head well separate from the sprue demolding part 61.

[0049] Because the sprue head formed at gate 72, if only the true gate portion 722 is present, the center of gravity of the sprue head will be significantly deviated from the axis of the gate pin 6. Since the ejected sprue head is not fully cooled, the shifted center of gravity will cause the incompletely cooled sprue head to rotate around the axis of the gate pin 6, affecting the gripper's ability to hold it. Furthermore, during the ejection process, the true gate is prone to elastic deformation; that is, the true gate portion 722 will release elastic force the instant it detaches from gate 72, which could potentially cause the entire sprue head to be ejected. Therefore, in this embodiment, a false gate portion 723 is provided. The false gate portion 723 and the true gate portion 722 are symmetrically positioned relative to the connecting pin portion 721 and are of balanced mass. The false gate portion 723 ensures that the center of gravity of the ejected sprue head remains at the axis of the gate pin 6, preventing the incompletely cooled sprue head from rotating around the axis of the gate pin 6.

[0050] In summary, firstly, by using the gate ejection section 61, the contact area between the gate pin 6 and the sprue is reduced without excessively weakening the constraint force of the gate pin 6 on the sprue. Therefore, the sprue is less likely to tilt or deviate uncontrollably when it is not completely detached from the mold cavity, and is less likely to bounce off at the moment of detachment. At the same time, the conical gate ejection section 61 transforms the force generated by the cooling and shrinkage of the sprue into a tendency for the sprue to loosen along the axial direction of the gate pin 6, ensuring the convenience of the robot's gripping. Secondly, due to the symmetrical balance between the true gate section 722 and the false gate section 723, the center of gravity of the sprue is balanced, so the sprue is less likely to deviate, deform, or rotate, which will not affect the subsequent gripping accuracy of the robot, and is less likely to bounce off at the moment of detachment from the mold cavity.

[0051] It is important to note that when the mold is opened, the sprue is in a state that is somewhat soft and has a certain degree of toughness. However, the ratio of softness to toughness is determined by the cooling efficiency. If the softness ratio is higher, the aforementioned factors will cause the sprue to deviate and deform after leaving the mold cavity, and will also cause the sprue to deviate and rotate relative to the gate pin 6. If the hardness ratio is higher, the aforementioned bounce-off situation will occur.

[0052] like Figure 4 As shown in the attached figure, A is the ejection direction of the gate pin 6, B is the direction of the force applied to the feed head by the mold when the feed head accumulates elastic potential energy, and C is the direction of the torque generated by the feed head due to the imbalance of the center of gravity.

[0053] In summary, the present application adopts the combination of the gate demolding part 61 and the symmetric arrangement of the real gate part 722 and the false gate part 723, which is expected to adapt to most types of sprues, that is, to adapt to various different soft and hard proportion cases, so that after the mold is opened, the sprue will not fly, and the relative attitude of the sprue and the gate pin 6 will not change too much, so as to facilitate the clamping of the mechanical hand, and this clamping is relatively convenient, and a large force is not needed to pull the sprue off the gate pin 6.

[0054] As shown in Figure 2 and Figure 4 , considering that the gate demolding part 61 is conical, the ejection sprue may rotate around the axis of the gate pin 6 when subjected to external force, affecting the subsequent clamping of the mechanical hand. Based on this, the gate pin 6 is inserted into the end of the rear mold core 21 and also has an anti-rotation limiting part 62, which is located on the side away from the gate 72 of the gate demolding part 61. The peripheral side wall of the anti-rotation limiting part 62 is used to connect with the sprue, and the non-circular arc outer wall of the anti-rotation limiting part 62 is connected with the sprue. Specifically, from the cross section of the anti-rotation limiting part 62 perpendicular to the axis direction of the gate pin 6, there is at least one straight line at the circumference of the cross section, which can limit the rotation of the sprue around the axis of the gate pin 6, and ensure that the attitude of the sprue is unique when the mechanical hand clamps the sprue each time.

[0055] If the sprue completely wraps the peripheral side wall of the anti-rotation limiting part 62, it may be difficult for the mechanical hand to clamp the sprue due to the excessive contact area between the anti-rotation limiting part 62 and the sprue, which may cause the wrapping force of the sprue on the anti-rotation limiting part 62 to be too large after cooling. To solve this contradiction, the anti-rotation limiting part 62 has a material connecting surface 621 and a cavity abutting surface 622. The material connecting surface 621 is used to connect with the sprue, and the cavity abutting surface 622 is used to abut against the inner wall of the cavity where the gate pin 6 is located. The material connecting surface 621 plays a role in preventing the sprue from rotating as described above, and the cavity abutting surface 622 reduces the contact area between the anti-rotation limiting part 62 and the sprue, making it easier for the mechanical hand to clamp the sprue.

[0056] In another embodiment of the present application, the internal space of the mold is very compact, and the position and angle of the real gate part 722 are determined by product design and glue feeding requirements, and often cannot be changed. The false gate part 723 serves as a cavity to balance the center of gravity of the sprue. If the included angle between the false gate part 723 and the needle connecting part 721 is equal to or greater than the included angle between the real gate part 722 and the needle connecting part 721, the volume of the rear mold core 21 needs to be larger to set the false gate part 723, which not only increases the production cost, but also occupies the space layout inside the mold.

[0057] Based on this, there are the following settings: the angle between the true water gap part 722 and the connecting needle part 721 is greater than the angle between the false water gap part 723 and the connecting needle part 721. Although this setting, intuitively, the volume of the false water gap part 723 is smaller than the volume of the true water gap part 722, wherein when pouring, part of the molten plastic flows to the true water gap part 722 and part of the molten plastic flows to the false water gap part 723, but the false water gap part 723 will be filled faster. After the product cavity is filled, the density of the sprue at the false water gap part 723 is greater than that at the true water gap part 722, so the balance of the center of gravity is realized by means of the density difference, and the internal space utilization of the mold is improved and the production cost is reduced.

[0058] In another embodiment of the present application, considering that the true water gap part 722 and the false water gap part 723 will release elastic force at the moment when the pin 21 is ejected, if the elastic forces released by the two are not synchronized and asymmetric, an impact torque in the opposite direction will be formed, causing the sprue to twist, shake or even fly off at the moment when the pin 21 is ejected. Based on this, there are the following settings: the length of the true water gap part 722 along the axis of the sprue pin 6 is consistent with the length of the false water gap part 723 along the axis of the sprue pin 6. By ensuring that the two water gap parts have the same axial length, the elastic deformation degree and energy storage state thereof in the ejection process tend to be synchronized. When the sprue is separated from the pin 21, the elastic potential energy stored by the true water gap part 722 and the false water gap part 723 is released at the same moment and on the same axis. Since they are symmetrically arranged relative to the sprue pin 6, the elastic forces generated by the two are in opposite directions, and the two opposite torque moments cancel each other out and neutralize, eliminating the phenomenon of the sprue flying off due to uneven release of internal stress at the moment when the sprue is separated from the pin 21.

[0059] In another embodiment of the present application, the true water gap part 722 serves as a channel connecting the product cavity. If the cross section of the true water gap along the melt flow direction is equal, it will cause melt pressure loss, and for high viscosity materials such as PC and POM, it is easy to cause defects such as insufficient filling and bubbles in the product cavity. In order to reduce the melt pressure loss, there are the following settings: the true water gap part 722 is narrowed in the direction away from the connecting needle part 721. A larger cross section is reserved on the side of the true water gap part 722 close to the connecting needle part 721 to ensure sufficient melt inlet flow, and the cross section gradually narrows along the melt flow direction to form a stable pressure boosting effect, solving the problem of insufficient filling of high viscosity materials.

[0060] In another embodiment of the present application, for products with high appearance requirements, if the gate 72 is arranged on the appearance surface, traces such as protrusions, depressions, etc. will be left, greatly affecting the appearance, and in the present embodiment, the product cavity is deep, and therefore the gate 72 needs to be connected to the inner side of the product, i.e. the non-appearance surface, and the gate 72 further comprises a supplementary connecting cavity portion 724 connecting the true gate portion 722 and the product cavity, the supplementary connecting cavity portion 724 extends away from the true gate portion 722 and is arranged towards the front mold plate 1, and the supplementary connecting cavity portion 724 extends in a straight line.

[0061] The supplementary connecting cavity portion 724 connects the inner wall of the product, and the traces of the gate 72 are not easy to be detected, thereby ensuring the perfection of the appearance of the product. In addition, the gate 72 is connected to the inner wall of the product, and it is usually easier to perform subsequent removal and trimming operations. In contrast, the appearance surface of the product needs to consider the impact on the surface quality when the gate is removed, and the operation is more difficult.

[0062] In summary, the aforementioned optimization of the gate 72 includes the arrangement of the anti-rotation limiting portion 62, the arrangement of the material connecting surface 621 and the cavity abutting surface 622, the angle relationship and axial length relationship between the true gate portion 722 and the false gate portion 723, the shape of the true gate portion 722, and the arrangement of the supplementary connecting cavity portion 724. These optimized structures are usually used in combination to improve the overall performance of the mold. The overall performance of the mold should be considered from two dimensions, one is whether the product made by the mold is good, and the other is how convenient it is to take out the product and the material head during frequent use of the mold. Therefore, from these two dimensions, the aforementioned optimization of the gate 72 is used in combination.

[0063] In addition, due to the aforementioned supplementary connecting cavity portion 724, when the product is demolded, the material head is located in the supplementary connecting cavity portion 724, and the ejector plate 5 is connected with a gate inclined ejector 51, the gate inclined ejector 51 is slidingly arranged on the rear mold core 21, and the outer wall of the gate inclined ejector 51 forms part of the inner wall of the product cavity and the supplementary connecting cavity portion 724. During mold opening, the gate inclined ejector 51 moves away from the part of the material head located in the supplementary connecting cavity portion 724, so that during the process of ejecting the product from the rear mold core 21, the gate inclined ejector 51 and the product are offset relative to the mold opening direction, to release the adhesion between the gate inclined ejector 51 and the product, and at the same time, the gate inclined ejector 51 also moves away from the part of the material head located in the supplementary connecting cavity portion 724, to release the adhesion between the gate inclined ejector 51 and the material head, thereby facilitating the subsequent removal of the product from the mold.

[0064] Since the gate screw 51 also separates the two parts of the sprue head located between the supplementary cavity 724 and the true gate 722, in order to achieve a smoother separation, the part of the gate screw 51 that mates with the supplementary cavity 724 will have a groove to provide more sufficient upward force so as to more smoothly separate the two parts of the sprue head located between the supplementary cavity 724 and the true gate 722.

[0065] After the final mold opening action is completed, on the sprue pin 6, the sprue head is located in the connecting pin part 721, the dummy sprue part 723, and the real sprue part 722. On the product, there is also a part of the sprue head located in the supplementary connecting cavity part 724. In order to facilitate the removal of the part of the sprue head located in the supplementary connecting cavity part 724 on the product, the connection between the supplementary connecting cavity part 724 and the product cavity will gradually narrow, so as to facilitate the subsequent removal of the remaining sprue head on the product.

[0066] like Figure 6 As shown, in another embodiment of this application, in order to improve the structural rigidity and bending resistance of the product, most products are provided with reinforcing ribs. Since the reinforcing ribs are thin plates, it is difficult to directly form the cavity where the reinforcing ribs are located on the rear mold core 21. In addition, the contact area between the reinforcing ribs and the rear mold core 21 is large. If the reinforcing ribs are forcibly ejected during demolding, the root of the reinforcing ribs may be broken. Based on this, the following configuration is provided: the rear mold core 21 includes a rear mold core 211 and a rear mold insert 212. The rear mold core 211 is provided with a gate 72 and is fixedly set on the rear mold plate 2. The rear mold insert 212 is fixedly inserted into the rear mold core 211, which will form a rib cavity 213 in the rear mold core 211. The cavity formed by the reinforcing ribs is formed by embedding the rear mold insert 212 into the rear mold core 211, which greatly reduces the difficulty of forming the cavity where the reinforcing ribs are located.

[0067] Meanwhile, the rear mold insert 212 is provided with an ejector guide hole 2121, and the ejector plate 5 is connected with an insert ejector pin 214. The insert ejector pin 214 slides through the ejector guide hole 2121 to directly eject the part of the product near the reinforcing rib, so as to promote demolding at the reinforcing rib. Since it acts directly near the reinforcing rib, it is less likely that other parts will demold first and the reinforcing rib will demold later, resulting in the reinforcing rib being torn off.

[0068] like Figure 7 and Figure 8As shown, in another embodiment of the present application, since the product after ejection will gradually cool down, and after cooling, it will tightly wrap the molded part. For the deep hole position in the product, if the ordinary ejector pin is used for ejection, the contact area between the ejector pin and the hole position is larger, and the product hole position has a strong wrapping force on the ejector pin after cooling, so that the robot is difficult to clamp the product. Therefore, it is necessary to reduce the wrapping force while ensuring that the hole position is ejected, and then the following settings are correspondingly provided. The ejector pin plate 5 is provided with a lower fixed plate 8 away from the rear die plate 2, the lower fixed plate 8 is fixedly arranged, the lower fixed plate 8 is provided with a hole forming pin 81, the hole forming pin 81 is slidably arranged through the rear die core 21; the ejector pin plate 5 is provided with a hole releasing guide sleeve 52, the hole releasing guide sleeve 52 is slidably arranged on the hole forming pin 81, and the hole releasing guide sleeve 52 is slidably arranged through the rear die core 21. The hole forming pin 81 is fixedly arranged on the lower fixed plate 8, one end of the hole forming pin 81 away from the lower fixed plate 8 is wrapped by the product, forming the inner wall of the product hole, and the hole releasing guide sleeve 52 is slidably arranged on the hole forming pin 81, and the end face of the hole releasing guide sleeve 52 away from the lower fixed plate 8 abuts against the product. In summary, during the ejection process, the hole forming pin 81 is fixedly arranged, the hole releasing guide sleeve 52 is slidably arranged with the ejector pin plate 5, the hole forming pin 81 is finally separated from the inner wall of the product hole, and the problem that the product cannot be clamped due to the excessive wrapping force after cooling is avoided.

[0069] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. An injection mold, characterized in that, include: The front template (1) is provided with a front mold core (11); The rear template (2) is provided with a rear mold core (21) and a rear mold slide seat (22); A stripper plate (3) is disposed on the front side of the front template (1); The upper fixing plate (4) is disposed on the front side of the stripping plate (3); Ejector plate (5) is disposed on the rear side of the rear template (2); The sprue pin (6) is connected to the ejector plate (5) and the rear mold core (21) respectively. The end of the sprue pin (6) inserted into the rear mold core (21) is tapered and narrows towards the front mold plate (1) to form a sprue demolding part (61). The upper fixed plate (4) is provided with a main runner (7), the stripper plate (3), the front template (1), the front mold core (11) and the rear mold slide seat (22) are provided with a branch runner (71), the rear mold core (21) is provided with a gate (72), the main runner (7), the branch runner (71) and the gate (72) are connected, the gate (72) is divided into a connecting pin part (721), a true gate part (722) and a false gate part (723), the connecting pin part (721) is connected to the cavity where the gate pin (6) is located, the true gate part (722) is connected to the product cavity, the true gate part (722) and the false gate part (723) are symmetrically and balanced with respect to the connecting pin part (721); The sprue pin (6) inserted into the end of the rear mold core (21) also has an anti-rotation limiting part (62). The anti-rotation limiting part (62) is located on the side of the sprue demolding part (61) away from the sprue (72). The peripheral outer wall of the anti-rotation limiting part (62) is used to connect with the sprue head. The non-circular arc outer wall of the anti-rotation limiting part (62) is connected with the sprue head. The outer wall of the anti-rotation limiting part (62) has a material connecting surface (621) and a cavity-attaching surface (622). The material connecting surface (621) is used to connect with the material head, and the cavity-attaching surface (622) is used to abut against the inner wall of the chamber where the gate needle (6) is located. The length of the true gate (722) along the axial direction of the gate needle (6) is the same as the length of the false gate (723) along the axial direction of the gate needle (6); The rear mold core (21) includes a rear mold core (211) and a rear mold insert (212). The rear mold core (211) is provided for the gate (72) and is fixedly mounted on the rear mold plate (2). The rear mold insert (212) is fixedly inserted into the rear mold core (211) to form a rib cavity (213) in the rear mold core (21). The rear mold insert (212) is provided with an ejector guide hole (2121). The ejector plate (5) is connected to an insert ejector pin (214), which slides through the ejector guide hole (2121). The ejector plate (5) is provided with a lower fixing plate (8) on the side away from the rear mold plate (2). The lower fixing plate (8) is fixedly installed and is provided with a hole-forming insert. The hole-forming insert slides through the rear mold core (21). The ejector plate (5) is provided with a hole-removing guide sleeve (52). The hole-removing guide sleeve (52) slides on the hole-forming insert and slides through the rear mold core (21).

2. The injection mold as described in claim 1, characterized in that: The angle between the true sprue (722) and the connecting needle (721) is greater than the angle between the false sprue (723) and the connecting needle (721).

3. The injection mold as described in claim 1, characterized in that: The true water inlet (722) is narrowed in the direction away from the connecting needle part (721).

4. The injection mold as described in claim 1, characterized in that: The gate (72) also includes a supplementary connecting cavity (724) that connects the true gate (722) and the product cavity. The supplementary connecting cavity (724) extends from the end away from the true gate (722) toward the front template (1).

5. The injection mold as described in claim 4, characterized in that: The ejector plate (5) is connected to a sprue riser (51), which slides through the rear mold core (21). The outer wall of the sprue riser (51) forms the product cavity and part of the inner wall of the supplementary connecting cavity (724).

Images