A high-speed plastic mold for secondary injection molding

Abstract

The present application discloses a high-speed plastic mold for secondary injection molding, comprising a front mold and a rear mold, wherein a cavity suitable for molding a workpiece is defined between the front mold and the rear mold, wherein the workpiece comprises a primary molding portion and a secondary molding portion, wherein the primary molding portion is molded by a primary injection molding process, and the secondary molding portion is molded by a secondary injection molding process, wherein the mold comprises a clamping surface, wherein the clamping surface is arranged perpendicular to the opening and closing directions of the front mold and the rear mold, wherein the maximum contour projection surface of the primary molding portion is the α surface, and the maximum contour projection surface of the secondary molding portion is the β surface, wherein the α surface and the β surface have an angle θ between them, satisfying θ=90°, and the β surface is arranged parallel to the clamping surface. One purpose of the present application is to provide a high-speed plastic mold for secondary injection molding that has a fast molding speed, a small mold volume, a simple structure, and a low cost.

Description

Technical Field

[0001] The present application relates to the field of secondary injection molding, and in particular to a high-speed plastic mold for secondary injection molding. Background Art

[0002] At present, secondary injection molding is a common injection molding process. The product undergoes primary molding and secondary molding processes respectively. Generally speaking, different plastic raw materials are used for primary molding and secondary molding (for example, PP or PE and other materials are used for primary molding, and soft rubber materials are used for secondary molding). The product after primary molding is placed in the secondary injection mold and subjected to secondary molding process, so that the manufactured workpiece has a primary molding part and a secondary molding part, and the materials of the primary molding part and the secondary molding part are generally different.

[0003] However, existing secondary injection molds have disadvantages such as slow molding speed, large mold volume, complex structure, and high cost, which are problems that technicians in this field need to solve. Summary of the Invention

[0004] One purpose of the present application is to provide a high-speed plastic mold for secondary injection molding with fast molding speed, small mold volume, simple structure and low cost.

[0005] To achieve the above objectives, the technical solution adopted in this application is: a high-speed plastic mold for secondary injection molding, comprising a front mold and a rear mold, wherein a cavity suitable for molding a workpiece is defined between the front mold and the rear mold, wherein the workpiece comprises a primary molding part and a secondary molding part, wherein the primary molding part is molded by a primary injection molding process, and the secondary molding part is molded by a secondary injection molding process, wherein the mold comprises a clamping surface, wherein the clamping surface is arranged perpendicular to the opening and closing directions of the front mold and the rear mold, wherein the maximum contour projection surface of the primary molding part is the α surface, and the maximum contour projection surface of the secondary molding part is the β surface, wherein an angle θ is formed between the α surface and the β surface, satisfying θ=90°, and the β surface is arranged parallel to the clamping surface.

[0006] It is worth mentioning that the maximum contour projection surfaces of the primary and secondary molding parts are projected onto the XOZ, YOZ, and XOY planes, respectively, with the α and β planes being the projection surfaces of the maximum contours. (Usually, the maximum contour refers to the area enclosed by the contour that is the largest.) Determining the maximum contour projection surface is to facilitate parting of the mold and thus determine the optimal parting surface. (For easier demolding, the parting surface should be located at the maximum contour of the plastic part in the demolding direction, that is, at the largest cross-section of the plastic part in that direction.)

[0007] Since the maximum outline projections of the primary and secondary molded parts are projections onto the XOZ, YOZ, and XOY planes, respectively, the maximum outline projections of the primary and secondary molded parts can only be perpendicular or parallel to each other. Setting the angle θ between the α and β planes to 90° means that the α and β planes 121 and 131 are not parallel but perpendicular to each other.

[0008] For a workpiece with a primary molded part and a secondary molded part, since the α and β surfaces are perpendicular to each other, the α surface of the primary molded part is usually set parallel to the mold surface of the primary mold in the mold design. In the secondary mold, the α surface of the primary molded part is also set parallel to the mold surface of the secondary mold. This will result in:

[0009] (1) In order to form the secondary molding part, an auxiliary slider needs to be added, and it is ensured that the auxiliary slider can maintain a fixed position relative to the inner wall of the cavity, thereby forming the secondary molding part. The addition of the auxiliary slider greatly increases the volume and structure of the secondary molding mold, and increases the manufacturing cost;

[0010] (2) It is also necessary to increase the clamping force of the injection molding machine so that the clamping force is applied to the auxiliary slider, thereby ensuring that during the actual injection molding process, the auxiliary slider will not be displaced or misaligned due to the increase in the mold cavity pressure, causing flash and overflow of the product;

[0011] (3) After the molding is completed, it is necessary to drive the auxiliary slider to move, so as to facilitate the demoulding of the workpiece. Driving the auxiliary slider to move increases the molding time, which greatly increases the overall molding cycle;

[0012] (4) Since soft rubber materials are generally used in the secondary molding process, they have a large mold adhesion force, making it difficult to separate the auxiliary slider from the secondary molding part on the workpiece. External force pulling is required for demolding, which further increases the molding cycle.

[0013] The high-speed plastic mold for secondary injection molding of the present application controls the β surface to be parallel to the mold surface of the secondary mold, that is, controls the α surface to be perpendicular to the mold surface of the secondary mold (because the α surface and the β surface are perpendicular to each other), which has the following beneficial effects:

[0014] (1) There is no need to add an auxiliary slider. Since the β surface is arranged parallel to the clamping surface of the secondary mold, the size and position of the cavity of the secondary molded part can be ensured by directly clamping the front mold and the rear mold of the secondary mold. This reduces the volume and structure of the mold, thereby reducing the production cost of the mold.

[0015] (2) Since the clamping force of the injection molding machine acts directly on the front mold and the rear mold, there is no need to use an auxiliary slider to change the direction and angle of the force, thereby ensuring direct transmission of the clamping force, thereby reducing the clamping force required by the mold of the present application during the injection molding process;

[0016] (3) After the molding is completed, there is no need to drive the slider to move, so the molding cycle and production tact can be reduced. In addition, during the mold opening process, the direction of the mold opening action is opposite to the direction of the mold sticking force, thereby ensuring the smooth separation of the workpiece and the front mold, which has the effect of reducing the mold production cycle.

[0017] Further preferably, the α surface is arranged parallel to the YOZ plane, the β surface is arranged parallel to the XOZ plane, the mold opening and closing directions are arranged along the Y-axis direction, and the projection length of the once-molded part on the α surface along the Z-axis direction is longer than the projection length of the once-molded part on the α surface along the Y-axis direction.

[0018] Further preferably, the workpiece protrudes from the mold in both upper and lower directions.

[0019] Further preferably, the primary molding part is provided with a through opening along the Y-axis, and a positioning insert is provided on the rear mold protruding along the Y-axis direction, and the outer wall of the positioning insert is suitable for contacting the inner wall of the through opening. During the secondary injection molding, the primary molding part is installed on the rear mold through the through opening and the positioning insert.

[0020] Further preferably, there are multiple groups of through openings, and auxiliary inserts are protruding from the front mold along the Y-axis direction, and the inner walls of the multiple groups of through openings respectively abut against the positioning inserts and the auxiliary inserts.

[0021] It is further preferred that the primary molding part has a plurality of undercuts in different directions, and a plurality of clearance grooves are provided in the mold, the clearance grooves are arranged along the mold opening and closing direction, and the notches of the clearance grooves are arranged toward the mold opening and closing direction, and in the secondary injection molding mold closing process, the undercuts are suitable for entering the clearance grooves along the mold opening and closing direction.

[0022] Further preferably, a demolding assembly is provided on the rear mold, and the demolding assembly includes a base and a demolding rod. The demolding rod is rotatably mounted on the base around the Z axis, and the demolding rod is suitable for contacting the rear side surface of the workpiece. When the secondary injection molding is completed, the demolding rod rotates around the Z axis and separates the workpiece from the rear mold.

[0023] Further preferably, the demolding assembly further comprises a mounting block, which is rotatably mounted on the base around the Z axis; a demolding rod and a driving rod are provided on the mounting block; the demolding rod is fixedly connected to the mounting block; the driving rod is slidably connected to the mounting block; a spring is provided between the mounting block and the driving rod; a driving groove is provided on the front mold along the mold opening and closing direction, and the notch of the driving groove is arranged towards the mold opening and closing direction; when the primary molding part is mounted on the rear mold, the primary molding part is adapted to contact the demolding rod and drive the mounting block to rotate counterclockwise around the Z axis; during the mold closing process, the mounting block and the driving rod are adapted to invade the driving groove; the driving rod and the mounting block slide relative to each other and compress the spring; after the mold is opened, the side wall of the mounting block separates from the inner wall of the driving groove, the spring restores its elastic deformation, and drives the driving rod and the mounting block to slide away from each other, thereby causing the mounting block to rotate clockwise around the Z axis, and finally driving the demolding rod to separate the workpiece from the rear mold.

[0024] Further preferably, the driving rod and the demoulding rod are both arranged along the negative direction of the X-axis, and after the mold is opened, the projections of the distal end of the driving rod and the distal end of the demoulding rod on the XOZ plane are staggered in the X-axis direction.

[0025] Further preferably, the demoulding components have two groups and are arranged along the Z-axis direction.

[0026] Compared with the prior art, the present invention has the following advantages:

[0027] (1) The high-speed plastic mold for secondary injection molding of the present application controls the β surface to be parallel to the clamping surface of the secondary mold, that is, controls the α surface to be perpendicular to the clamping surface of the secondary mold (because the α surface and the β surface are perpendicular to each other), so there is no need to add an auxiliary slider. Since the β surface is parallel to the clamping surface of the secondary mold, the clamping action is directly performed by the front mold and the rear mold of the secondary mold, which can ensure the size and position of the cavity of the secondary molding part, thereby reducing the volume and structure of the mold, thereby reducing the production cost of the mold;

[0028] (2) Since the clamping force of the injection molding machine acts directly on the front mold and the rear mold, there is no need to use an auxiliary slider to change the direction and angle of the force, thereby ensuring direct transmission of the clamping force, thereby reducing the clamping force required by the mold of the present application during the injection molding process;

[0029] (3) After the molding is completed, there is no need to drive the slider to move, so the molding cycle and production tact can be reduced. In addition, during the mold opening process, the direction of the mold opening action is opposite to the direction of the mold sticking force, thereby ensuring the smooth separation of the workpiece and the front mold, which has the effect of reducing the mold production cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic diagram of an embodiment of a workpiece of the present application, showing a primary molding portion and a secondary molding portion;

[0031] Figure 2 A schematic diagram of an embodiment of a workpiece of the present application, showing the α surface;

[0032] Figure 3 is a schematic diagram of a secondary molded portion of a workpiece of the present application, showing the β surface;

[0033] Figure 4 A schematic diagram of a workpiece of the present application, showing the α-plane and the β-plane;

[0034] Figure 5 Schematic diagram of a mold in the prior art;

[0035] Figure 6 This is an exploded view of a mold in the prior art, showing that the mating surfaces of the primary molding and the secondary molding are parallel to each other;

[0036] Figure 7 A schematic diagram of an embodiment of a high-speed plastic mold of the present application;

[0037] Figure 8 This is an exploded view of an embodiment of the high-speed plastic mold of the present application, showing that the β surface is arranged parallel to the mold surface;

[0038] Figure 9 This is a schematic diagram of an embodiment of the high-speed plastic mold of the present application, showing that both the upper and lower ends of the primary molding portion protrude from the mold arrangement;

[0039] Figure 10 A schematic diagram of an embodiment of a high-speed plastic mold of the present application, showing a positioning insert;

[0040] Figure 11 A schematic diagram of an embodiment of a high-speed plastic mold of the present application, showing a through port;

[0041] Figure 12 A schematic diagram of an embodiment of a high-speed plastic mold of the present application, showing auxiliary inserts;

[0042] Figure 13 A schematic diagram of an embodiment of a high-speed plastic mold of the present application, showing a clearance groove;

[0043] Figure 14 A schematic diagram of an embodiment of a high-speed plastic mold of the present application, showing a demoulding component;

[0044] Figure 15 An exploded view of a demoulding assembly of an embodiment of a high-speed plastic mold of the present application;

[0045] Figure 16 A schematic diagram of an embodiment of a high-speed plastic mold of the present application, showing the rotation of the demoulding rod;

[0046] Figure 17 A schematic diagram of an embodiment of a high-speed plastic mold of the present application, showing a demoulding rod driving a workpiece to move;

[0047] Figure 18 A cross-sectional view of an embodiment of the high-speed plastic mold of the present application, showing the driving rod abutting against the workpiece;

[0048] Figure 19 A cross-sectional view of an embodiment of the high-speed plastic mold of the present application, showing the spring restoring its deformation and driving the mounting block to rotate;

[0049] Figure 20 A cross-sectional view of an embodiment of the high-speed plastic mold of the present application, showing the staggered arrangement of the distal ends of the driving rod and the demoulding rod;

[0050] Figure 21 This is a cross-sectional view of an embodiment of the high-speed plastic mold of the present application, showing the primary molding part driving the demoulding rod to rotate;

[0051] Figure 22 An embodiment of the high-speed plastic mold of this application Figure 18 A partial enlarged cross-sectional view at position A in the middle shows the first through hole, the second through hole, and the third through hole;

[0052] Figure 23 This is a cross-sectional view of an embodiment of the high-speed plastic mold of the present application, showing the auxiliary insert abutting against the driving rod.

[0053] In the figure: 1. workpiece; 11. undercut; 12. primary molding part; 121. α surface; 122. through-port; 13. secondary molding part; 131. β surface; 2. demoulding assembly; 21. base; 22. demoulding rod; 23. driving rod; 231. sliding section; 2311. spring; 232. limiting section; 233. limiting screw; 24. mounting block; 241. first through hole; 242. second through hole; 243. third through hole; 3. front mold; 31. auxiliary insert; 32. driving groove; 4. rear mold; 41. positioning insert; 42. demoulding assembly mounting groove; 421. anti-rotation surface; 5. cavity; 6. closing surface; 7. clearance groove; 100. auxiliary slider. DETAILED DESCRIPTION

[0054] Below, the present application is further described in conjunction with specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0055] In the description of this application, it should be noted that for directional words, such as the terms "center", "horizontal", "longitudinal", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and so on, the directions and positional relationships indicated are based on the directions or positional relationships shown in the accompanying drawings, which are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and cannot be understood as limiting the specific scope of protection of this application.

[0056] It should be noted that the terms "first", "second", etc. in the description and claims of this application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0057] The terms "comprises" and "having" and any variations thereof in the specification and claims of this application are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus that includes a series of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, product or apparatus.

[0058] like Figures 1 to 4 As shown, the workpiece 1 is a side panel of a car seat, which has a primary molding part 12 and a secondary molding part 13. A coordinate system XYZ is established on the workpiece 1 as shown in FIG. Figures 1 to 4 As shown, the secondary molding part 13 is made of soft rubber material, and the primary molding part 12 also has a plurality of undercuts 11 with different demolding directions. It is worth mentioning that the maximum contour projection surfaces of the primary molding part 12 and the secondary molding part 13 are the projections of the primary molding part 12 and the secondary molding part 13 on the XOZ, YOZ and XOY planes respectively, and the projection surfaces of the maximum contours are selected as α surface 121 and β surface 131 respectively. (Usually the maximum contour refers to the area surrounded by the contour with the largest area) The maximum contour projection surface is determined to facilitate the parting surface of the mold, so as to determine the best parting surface (in order to facilitate demolding, the position of the parting surface should be selected at the maximum outer contour of the plastic part in the demolding direction, that is, at the maximum cross-section of the plastic part in this direction) In this specific embodiment, as Figure 2 As shown, the primary molded portion 12 and the α surface 121 are shown; Figure 3 As shown, the secondary molded portion 13 and the β surface 131 are shown.

[0059] For the workpiece 1 having the primary molding portion 12 and the secondary molding portion 13, since the α surface 121 and the β surface 131 are perpendicular to each other, in the design of the mold, the α surface 121 of the primary molding portion 12 is usually set parallel to the die surface 6 of the primary molding mold, and in the secondary molding mold, the α surface 121 of the primary molding portion 12 is still set parallel to the die surface 6 of the secondary molding mold, such as Figure 5 and Figure 6 It shows that in common mold design, the direction of the mold surface 6 of the primary molding mold and the secondary molding mold is parallel to the YOZ plane. This will lead to the following consequences:

[0060] (1) In order to form the secondary molding portion 13, an auxiliary slider 100 needs to be added, and it is ensured that the auxiliary slider 100 can maintain a fixed position relative to the inner wall of the cavity 5, thereby forming the secondary molding portion 13. The addition of the auxiliary slider 100 significantly increases the volume and structure of the secondary molding mold, and increases the manufacturing cost;

[0061] (2) It is also necessary to increase the clamping force of the injection molding machine so that the clamping force is applied to the auxiliary slider 100, thereby ensuring that during the actual injection molding process, the auxiliary slider 100 will not be displaced or misaligned due to the increase in the mold cavity pressure, thereby causing flash and overflow of the product;

[0062] (3) After the molding is completed, it is necessary to drive the auxiliary slider 100 to move, so as to facilitate the demoulding of the workpiece 1. Driving the auxiliary slider 100 to move increases the molding time, which greatly increases the overall molding cycle;

[0063] (4) Since soft rubber materials are generally used in the secondary molding process, they have a large mold adhesion force, making it difficult to separate the auxiliary slider 100 from the secondary molding portion 13 on the workpiece 1. External force pulling is required for demolding, which further increases the molding cycle.

[0064] Therefore, the inventors of this application have developed a high-speed plastic mold for secondary injection molding, one embodiment of which is as follows: Figures 7 to 23 As shown, it includes a front mold 3 and a rear mold 4, and a cavity 5 suitable for molding a workpiece 1 is defined between the front mold 3 and the rear mold 4. The workpiece 1 includes a primary molding part 12 and a secondary molding part 13. The primary molding part 12 is molded by a primary injection molding process, and the secondary molding part 13 is molded by a secondary injection molding process. The mold includes a clamping surface 6, and the clamping surface 6 is set perpendicular to the opening and closing directions of the front mold 3 and the rear mold 4 (in this specific embodiment, it is set parallel to the XOZ plane). The maximum contour projection surface of the primary molding part 12 is the α surface 121, and the maximum contour projection surface of the secondary molding part 13 is the β surface 131. There is an angle θ between the α surface 121 and the β surface 131, satisfying θ=90°, and the β surface 131 is set parallel to the clamping surface 6.

[0065] Because the maximum outline projections of the primary molded portion 12 and the secondary molded portion 13 are projections onto the XOZ, YOZ, and XOY planes, respectively, the maximum outline projections of the primary molded portion 12 and the secondary molded portion 13 can only be perpendicular or parallel to each other. Setting the angle θ between the α-plane 121 and the β-plane 131 to 90° means that the α-plane and the β-plane are not parallel but perpendicular to each other.

[0066] The high-speed plastic mold for secondary injection molding of the present application controls the β surface 131 to be arranged parallel to the die-clamping surface 6 of the secondary mold, that is, controls the α surface 121 to be arranged perpendicular to the die-clamping surface 6 of the secondary mold (because the α surface 121 and the β surface 131 are perpendicular to each other), which has the following beneficial effects:

[0067] (1) There is no need to add an auxiliary slider 100. Since the β surface 131 is arranged parallel to the clamping surface 6 of the secondary mold, the clamping action can be performed directly by the front mold 3 and the rear mold 4 of the secondary mold to ensure the size and position of the cavity of the secondary molding part 13. This reduces the volume and structure of the mold, thereby reducing the production cost of the mold.

[0068] (2) Since the clamping force of the injection molding machine acts directly on the front mold 3 and the rear mold 4, there is no need to change the direction and angle of the force through the auxiliary slider 100, thereby ensuring direct transmission of the clamping force, thereby reducing the clamping force required by the mold of the present application during the injection molding process;

[0069] (3) After the molding is completed, there is no need to drive the auxiliary slider 100 to move, so the molding cycle and the production rhythm can be reduced. In addition, during the mold opening process, the mold opening action direction is opposite to the mold sticking force direction, thereby ensuring that the workpiece 1 and the front mold 3 are smoothly separated, which has the effect of reducing the mold production cycle.

[0070] After experiments, in the actual production process, the mold designed with traditional scheme is Figure 5 and Figure 6 As shown, its production cycle is about 30 seconds, and the high-speed mold using the structural design of this application is as shown in FIG. Figure 7 and Figure 8 As shown, the production cycle is about 15 seconds, which greatly reduces the production cycle, greatly reduces the volume and weight of the secondary mold, and effectively reduces the number of injection molding machines required, saving production costs.

[0071] More preferably, Figure 8 and Figure 9As shown, the α surface 121 is arranged parallel to the YOZ plane, the β surface 131 is arranged parallel to the XOZ plane, the mold opening and closing directions are arranged along the Y-axis direction, and the projection length of the primary molded portion 12 on the α surface 121 along the Z-axis direction is longer than the projection length of the primary molded portion 12 on the α surface 121 along the Y-axis direction. Controlling the projection length of the primary molded portion 12 on the α surface 121 along the Z-axis direction to be longer than the projection length of the primary molded portion 12 on the α surface 121 along the Y-axis direction can ensure that the long side of the primary molded portion 12 is arranged along the Z-axis direction during the production process. It is easy to understand that the Z-axis direction refers to the up-down direction. Making the primary molded portion 12 protrude from the mold design in the up-down direction can reduce the required X-axis and Y-axis dimensions during the mold production process, thereby effectively reducing the mold volume and preventing safety hazards caused during the actual production process.

[0072] It is further preferred that the workpiece 1 protrudes from the mold in both the up and down directions. It is worth mentioning that the up and down directions refer to the Z-axis direction. Compared with the traditional design (such as Figure 5 and Figure 6 As shown), it is necessary to control the cavity 5 of the secondary molding part 13 to be located in the middle of the mold as much as possible. Since it adopts the locking method of the auxiliary slider 100, it is designed to be in the middle as much as possible to effectively transmit the clamping force and reduce the possibility of flash and overflow. In the mold of this application, the locking of the cavity 5 of the secondary molding part 13 depends on the clamping force between the front mold 3 and the rear mold 4 (as shown). Figure 7 and Figure 8 As shown), the required clamping force is greatly reduced, and there is no need to make the cavity 5 of the secondary molding part 13 as close to the middle of the mold as possible, so the workpiece 1 will protrude from the mold design in both the upper and lower directions (as shown). Figure 9 As shown), the volume and weight of the mold are reduced, and the manufacturing cost of the mold is reduced.

[0073] Further preferably, the primary molding part 12 is provided with a through-hole 122 along the Y-axis, and a positioning insert 41 is provided on the rear mold 4 protruding along the Y-axis direction. The outer wall of the positioning insert 41 is adapted to contact the inner wall of the through-hole 122. During the secondary injection molding, the primary molding part 12 is installed on the rear mold 4 through the through-hole 122 and the positioning insert 41. In conventional technology, it is relatively difficult to position and install the primary molding part 12 with the rear mold 4 of the secondary mold. It is necessary to drive the auxiliary slider 100 to move in order to achieve the positioning of the primary molding part 12. Since the primary molding part 12 is provided with the through-hole 122 along the Y-axis and is consistent with the mold opening and closing direction, in the actual production process, it is only necessary to install the through-hole 122 on the workpiece 1 on the positioning insert 41, so that the primary molding part 12 can be installed on the rear mold 4, facilitating its secondary injection molding. Through this design, the purpose of reducing the mold volume and optimizing the production cycle can be further achieved.

[0074] More preferably, Figures 9 to 13 As shown, there are multiple groups of through openings 122, and auxiliary inserts 31 are provided on the front mold 3 protruding along the Y-axis direction. The inner walls of the multiple groups of through openings 122 respectively contact the positioning inserts 41 and the auxiliary inserts 31. The auxiliary inserts 31 protruding in the Y-axis direction can further fix the relative position of the primary molding part 12 on the workpiece 1 in the mold, reduce the design of the auxiliary slider 100, and prevent the primary molding part 12 from being misplaced in the mold. In addition, the auxiliary inserts 31 and the positioning inserts 41 are provided to act at the same time, which can further fix the relative position of the primary molding part 12 in the mold and prevent it from shaking during the secondary injection molding process. Since the mold of the present application is relatively small in size, the upper and lower ends of the primary molding part 12 on the workpiece 1 protrude from the mold design. Therefore, it is necessary to control the shaking of the workpiece 1 during the actual secondary injection molding process to prevent the primary molding part 12 from being misplaced.

[0075] More preferably, Figure 12 and Figure 13 As shown, the primary molding part 12 has a plurality of undercuts 11 in different directions, and a plurality of clearance grooves 7 are provided in the mold. The clearance grooves 7 are provided along the mold opening and closing direction, and the notches 7 of the clearance grooves are provided in the mold opening and closing direction. In the secondary injection molding closing process, the undercuts 11 are suitable for entering the clearance grooves 7 along the mold opening and closing direction. The undercuts 11 in different directions refer to undercuts 11 with different demoulding directions during the primary injection molding process. Providing the clearance grooves 7 and making the clearance grooves 7 along the mold opening and closing direction, and making the notches 7 of the clearance grooves face the mold opening and closing direction, can facilitate the undercuts 11 to directly invade the clearance grooves 7 during the mold closing process of the secondary injection molding, without the need to design multiple sliders to lock the position of the undercuts 11.

[0076] More preferably, Figure 10 、 Figure 14 and Figure 15 As shown, the rear mold 4 is provided with a demoulding assembly 2, which includes a base 21 and a demoulding rod 22. The demoulding rod 22 is rotatably mounted on the base 21 around the Z axis. The demoulding rod 22 is suitable for contacting the rear side of the workpiece 1. When the secondary injection molding is completed, the demoulding rod 22 rotates around the Z axis and separates the workpiece 1 from the rear mold 4. Figure 16 and Figure 17 As shown, when the demoulding rod 22 is required to rotate around the Z axis, Figure 16 As shown by the arrow, it will drive the workpiece 1 to move in the negative direction of the Y axis, as shown in Figure 17As shown, the workpiece 1 is separated from the rear mold 4. The demolding assembly 2 has a simple structure and can reduce the number of ejector pins used in the mold, further reducing mold design and operating costs. Furthermore, during the secondary injection molding process, the secondary molding portion 13 is made of soft rubber, which has a strong mold adhesion. The demolding rod 22 is used to separate the workpiece 1, providing a strong demolding force, making it easy to separate the secondary molding portion 13 and the rear mold 4, further reducing production cycle time.

[0077] More preferably, Figures 15 to 22 As shown, the demoulding assembly 2 also includes a mounting block 24, which is rotatably mounted on the base 21 around the Z axis. A demoulding rod 22 and a driving rod 23 are provided on the mounting block 24. The demoulding rod 22 is fixedly connected to the mounting block 24, and the driving rod 23 is slidably connected to the mounting block 24. A spring 2311 is provided between the mounting block 24 and the driving rod 23. A driving groove 32 is provided on the front mold 3 along the mold opening and closing direction, and the notch of the driving groove 32 is arranged toward the mold opening and closing direction. When the primary molding part 12 is mounted on the rear mold 4, the primary molding part 12 It is suitable for contacting the demoulding rod 22 and driving the mounting block 24 to rotate counterclockwise around the Z axis. During the mold closing process, the mounting block 24 and the driving rod 23 are suitable for invading the driving groove 32. The driving rod 23 and the mounting block 24 slide relative to each other and compress the spring 2311. After the mold is opened, the side wall of the mounting block 24 is separated from the inner wall of the driving groove 32. The spring 2311 restores its elastic deformation and drives the driving rod 23 and the mounting block 24 to slide back to back, thereby causing the mounting block 24 to rotate clockwise around the Z axis, and finally driving the demoulding rod 22 to separate the workpiece 1 and the rear mold 4.

[0078] In the actual production process, Figure 21 As shown, the workpiece 1 moves downward in the direction of the arrow until it hits the demoulding rod 22, driving the demoulding rod 22 and the mounting block 24 to rotate counterclockwise, and then controls the driving rod 23 and the mounting block 24 to move toward each other, thereby compressing the spring 2311. When the secondary injection molding is completed, as shown in FIG. Figure 18 and Figure 19 As shown, the front mold 3 and the rear mold 4 are separated, and under the action of the elastic force of the spring 2311, a negative force along the X axis is generated on the mounting block 24 (as shown in FIG. Figure 19 As shown), the mounting block 24 is driven to rotate clockwise, thereby driving the demoulding rod 22 to rotate as shown Figure 22 As shown, the demoulding rod 22 is then used to separate the workpiece 1 from the rear mold 4 .

[0079] More preferably, Figure 20As shown, the rear mold 4 is provided with a demolding assembly mounting groove 42 along the mold opening and closing direction. When the primary molding portion 12 is mounted on the rear mold 4, the primary molding portion 12 is adapted to abut against the demolding rod 22 and drive the mounting block 24 to rotate counterclockwise about the Z-axis, causing the demolding rod 22 to penetrate into the demolding assembly mounting groove 42. The provision of the demolding assembly mounting groove 42 can further reduce the volume of the rear mold 4 occupied by the demolding assembly 2, thereby further reducing the volume of the mold of the present application.

[0080] More preferably, Figure 20 As shown, the demolding assembly mounting groove 42 is provided with a rotation-blocking surface 421 on its wall. After the mold is opened, the rotation-blocking surface 421 is adapted to limit the maximum clockwise rotation angle of the mounting block 24 about the Z axis. The rotation-blocking surface 421 is configured to contact the sidewall of the mounting block 24, thereby limiting the maximum clockwise rotation angle of the mounting block 24 about the Z axis. This prevents the mounting block 24 from rotating too far, which would make it difficult for the subsequent workpiece 1 to push the demolding rod 22 to rotate.

[0081] More preferably, Figure 22 As shown, the driving rod 23 includes a sliding section 231, which is slidably connected to the mounting block 24. One end of the sliding section 231 extends along the axis of the sliding section 231 to form a limiting section 232. The diameter of the limiting section 232 is larger than that of the sliding section 231. A spring 2311 is sleeved on the exterior of the sliding section 231, with one end of the spring 2311 connected to the end surface of the limiting section 232 and the other end of the spring 2311 connected to the mounting block 24. The provision of the sliding section 231 and the limiting section 232, with the diameter of the limiting section 232 being larger than that of the sliding section 231, facilitates the installation of the spring 2311 and facilitates the movement of the limiting section 232, thereby driving the movement of the sliding section 231, thereby compressing the spring 2311. After the mold is opened, the demolding rod 22 automatically rotates under the action of the spring, achieving the purpose of rapid demolding. Compared with ejector pin demolding, the demolding force is greater and the demolding speed is faster.

[0082] More preferably, Figure 22As shown, the mounting block 24 is provided with a first through hole 241, a second through hole 242 and a third through hole 243. The first through hole 241 and the third through hole 243 are connected through the second through hole 242, and the diameters of the first through hole 241 and the third through hole 243 are both larger than the diameter of the second through hole 242. The sliding section 231 is slidably connected to the third through hole 243. A limiting section 232 is axially provided at one end of the sliding section 231, and a limiting screw 233 is axially installed at the other end of the sliding section 231. The limiting screw 233 is slidably connected to the first through hole 241. The end face of the first through hole 241 and the end face of the limiting screw 233 cooperate with each other and limit the maximum displacement of the driving rod 23 along the positive direction of the X-axis. The end face of the sliding section 231 and the end face of the third through hole 243 cooperate with each other and limit the maximum displacement of the driving rod 23 along the negative direction of the X-axis. Figure 22 As shown, when the drive rod 23 moves in the positive direction of the X-axis, the left end surface of the limit screw 233 contacts the end surface of the first through hole 241, thereby limiting further movement of the drive rod 23 in the positive direction of the X-axis. When the drive rod 23 moves in the negative direction of the X-axis, the right end surface of the sliding section 231 contacts the end surface of the third through hole 243, limiting further movement of the drive rod 23 in the negative direction of the X-axis. This arrangement prevents the drive rod 23 from separating from the mounting block 24 during sliding, thereby causing failure of the demolding assembly 2.

[0083] More preferably, Figure 23 As shown, an auxiliary insert 31 is provided on the front mold 3 protruding along the Y-axis direction, and the workpiece 1 has a through opening 122. The inner wall of the through opening 122 abuts against the auxiliary insert 31. After the mold is closed, the side wall of the auxiliary insert 31 is adapted to abut against the drive rod 23, causing the drive rod 23 to slide in the negative direction of the X-axis and compress the spring 2311. The auxiliary insert 31 can drive the drive rod 23 to slide in the negative direction of the X-axis, thereby compressing the spring 2311. This facilitates the spring 2311 to recover its elastic deformation after the mold is opened, and drives the mounting block 24 to rotate clockwise, thereby enabling the demolding rod 22 to drive the workpiece 1 to separate from the rear mold 4.

[0084] More preferably, Figure 18 As shown, when the primary molding portion 12 is mounted on the rear mold 4, the side wall of the workpiece 1 is adapted to abut against the driving rod 23, causing the driving rod 23 to slide in the negative direction of the X-axis and compress the spring 2311. Alternatively, the side wall of the workpiece 1 can drive the driving rod 23 to slide, thereby compressing the spring 2311.

[0085] More preferably, Figure 20As shown, the driving rod 23 and the demoulding rod 22 are both arranged along the positive direction of the X-axis, and after the mold is opened, the projections of the distal ends of the driving rod 23 and the distal ends of the demoulding rod 22 on the XOY plane are offset in the X-axis direction. In this specific embodiment, the projections of the distal ends of the driving rod 23 and the distal ends of the demoulding rod 22 on the XOY plane are offset in the X-axis direction, that is, the distal end of the driving rod 23 is controlled to have a distance X1 relative to the rear mold 4 in the X-axis direction, and the distal end of the demoulding rod 22 is controlled to have a distance X2 relative to the rear mold 4 in the X-axis direction, satisfying X1≠X2, thereby facilitating the installation of the workpiece 1 on the rear mold 4. Specifically, X2>X1 can also be made to ensure that when the workpiece 1 moves downward, as shown in FIG. Figure 21 As shown, it will interfere with the demolding rod 22 and drive the mounting block 24 to rotate, but will not interfere with the driving rod 23, which can make the installation of the workpiece 1 more convenient. Of course, the driving rod 23 will slide relative to the mounting block 24. Therefore, during the downward displacement of the workpiece 1, it can drive the driving rod 23 to slide, thereby ensuring that X2>X1.

[0086] More preferably, Figure 16 and Figure 17 As shown, there are two sets of demolding assemblies 2, which are arranged along the Z-axis. Providing two sets of demolding assemblies 2 can increase the demolding force during the demolding process, facilitate the separation between the workpiece 1 and the rear mold 4, and provide two sets of demolding assemblies 2 to reduce the swing of the workpiece 1 during the demolding process, reduce damage to the surface of the workpiece 1, and effectively reduce damage to the mold core, thereby extending the service life of the mold.

[0087] The above describes the basic principles, main features, and advantages of the present application. Those skilled in the art should understand that the present application is not limited to the above-described embodiments. The above-described embodiments and the specification merely illustrate the principles of the present application. Various changes and improvements may be made to the present application without departing from the spirit and scope of the present application. These changes and improvements fall within the scope of the present application for which protection is sought. The scope of protection claimed by the present application is defined by the appended claims and their equivalents.

Claims

1. A high-speed plastic mold for secondary injection molding, comprising a front mold and a rear mold, wherein a cavity suitable for molding a workpiece is defined between the front mold and the rear mold, wherein the workpiece comprises a primary molding portion and a secondary molding portion, wherein the primary molding portion is molded by a primary injection molding process and the secondary molding portion is molded by a secondary injection molding process, characterized in that: The mold includes a mold surface, the mold surface is arranged perpendicular to the opening and closing directions of the front mold and the rear mold, the maximum contour projection surface of the primary molding part is the α surface, the maximum contour projection surface of the secondary molding part is the β surface, an angle θ is formed between the α surface and the β surface, and θ=90° is satisfied, and the β surface is arranged parallel to the mold surface; The α surface is arranged parallel to the YOZ plane, the β surface is arranged parallel to the XOZ plane, the mold opening and closing directions are arranged along the Y axis, and the projection length of the primary molded part on the α surface along the Z axis is longer than the projection length of the primary molded part on the α surface along the Y axis; The rear mold is provided with a demoulding assembly, which includes a base and a demoulding rod. The demoulding rod is rotatably mounted on the base around a Z axis. The demoulding rod is adapted to abut against the rear side surface of the workpiece. When the secondary injection molding is completed, the demoulding rod rotates around the Z axis to separate the workpiece from the rear mold. The demoulding assembly also includes a mounting block, which is rotatably mounted on the base around the Z axis. A demoulding rod and a driving rod are provided on the mounting block, the demoulding rod is fixedly connected to the mounting block, and the driving rod is slidably connected to the mounting block. A spring is provided between the mounting block and the driving rod. A driving groove is provided on the front mold along the mold opening and closing direction, and the notch of the driving groove is set towards the mold opening and closing direction. When the primary molding part is mounted on the rear mold, the primary molding part is suitable for contacting the demoulding rod and driving the mounting block to rotate counterclockwise around the Z axis. During the mold closing process, the mounting block and the driving rod are suitable for invading the driving groove. The driving rod and the mounting block slide relative to each other and compress the spring. After the mold is opened, the side wall of the mounting block separates from the inner wall of the driving groove, the spring restores its elastic deformation, and drives the driving rod and the mounting block to slide away from each other, thereby causing the mounting block to rotate clockwise around the Z axis, and finally driving the demoulding rod to separate the workpiece from the rear mold.

2. A high-speed plastic mold for secondary injection molding according to claim 1, characterized in that: The workpiece protrudes from the mold in both upper and lower directions.

3. A high-speed plastic mold for secondary injection molding according to claim 1, characterized in that: The primary molding part is provided with a through opening along the Y-axis, and a positioning insert is provided on the rear mold protruding along the Y-axis direction. The outer wall of the positioning insert is suitable for contacting the inner wall of the through opening. During the secondary injection molding, the primary molding part is installed on the rear mold through the through opening and the positioning insert.

4. A high-speed plastic mold for secondary injection molding according to claim 3, characterized in that: There are multiple groups of through openings, and auxiliary inserts are protruding from the front mold along the Y-axis direction. The inner walls of the multiple groups of through openings respectively abut against the positioning inserts and the auxiliary inserts.

5. The high-speed plastic mold for secondary injection molding according to claim 1, characterized in that: The primary molding part has multiple undercuts in different directions, and the mold is provided with multiple give-way grooves, which are arranged along the mold opening and closing direction, and the notches of the give-way grooves are arranged toward the mold opening and closing direction. In the secondary injection molding mold closing process, the undercuts are suitable for entering the give-way grooves along the mold opening and closing direction.

6. A high-speed plastic mold for secondary injection molding according to claim 1, characterized in that: The driving rod and the demoulding rod are both arranged along the negative direction of the X-axis, and after the mold is opened, the projections of the distal ends of the driving rod and the demoulding rod on the XOZ plane are staggered in the X-axis direction.

7. The high-speed plastic mold for secondary injection molding according to claim 1, characterized in that: The demoulding components have two groups and are arranged along the Z-axis direction.

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