Core pulling mechanism of injection mold

Abstract

The invention provides a core pulling mechanism of an injection mold, and belongs to the technical field of molds. The core-pulling mechanism solves the problem that an existing core-pulling mechanism is insufficient in reliability. The core-pulling mechanism of the injection mold comprises a pull rod which is arranged on a fixed mold and can move downwards relative to the fixed mold, when the pull rod moves downwards, a core-pulling sliding block can be driven to slide out of a mold cavity, and a positioning clamping groove is formed in the outer wall of the pull rod; a locking assembly which is located below the pull rod and provided with an inserting hole is arranged on the movable mold, the lower end of the pull rod is inserted into the inserting hole in a sliding mode, a locking ball and an elastic piece are arranged in the locking assembly, and the locking ball can partially stretch into the inserting hole under the action of the elastic piece and is connected with a positioning clamping groove in the pull rod in a clamped mode. The core pulling mechanism further comprises a driving assembly capable of driving the locking assembly to move downwards relative to the movable mold. The mold opening mechanism has good working reliability, and meanwhile the problem that the mold or a product is strained in the mold opening process due to the fact that the mold action sequence is disordered is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of molds and relates to a core pulling mechanism of an injection mold. Background Art

[0002] In the injection mold molding process, when producing some products with complex shapes or deep cavities, especially when the geometric shape of the product makes it impossible to effectively demold the traditional core pulling method, a tunnel core pulling mechanism will be used to achieve smooth demolding of the product.

[0003] The existing tunnel core pulling mechanism usually uses a cylinder to drive the core pulling slider. Before the injection molding machine opens the mold, the core pulling slider is pulled out of the mold cavity by the cylinder, and then the mold is opened to take out the product. After the injection molding machine closes the mold, the core pulling slider is reset to its position by the cylinder before injection molding production. For example, a tunnel core pulling structure disclosed in the patent document (application number: 202310752442.0) includes a fixed mold and a movable mold. The opposite surfaces of the fixed mold and the movable mold are provided with cavities. When the fixed mold and the movable mold are combined, the cavity between them forms a mold cavity; the outer surface of the fixed mold is fixedly installed with a cylinder, and the telescopic end of the cylinder is provided with an inclined tunnel core pulling mechanism, which is used to drive the core pulling away from the product to realize product demolding; the inclined tunnel core pulling mechanism includes a slider seat slidably connected to the inside of the fixed mold, and the slider seat is connected to an inclined core pulling on the side close to the fixed mold; the telescopic end of the cylinder is fixedly installed with a shift block, and the shift block is located at the inclined surface of the slider seat. During the opening process of the mold, the tunnel core pulling mechanism drives the shift block to move to the side away from the slider seat through the oil cylinder, so that the slider seat attached to the surface of the shift block will also withdraw together. The slider seat drives the oblique core pulling away from the molded product to achieve smooth demoulding of the product. The above core pulling mechanism has the following shortcomings in the actual production process:

[0004] 1. During the injection molding process, the oblique core puller needs to be extended into the mold cavity to form a hole or cavity structure on the product. At this time, the plastic melt in the mold cavity will generate a certain pressure during injection molding. The plastic melt pressure will directly act on the oblique core puller, and then be transmitted to the piston rod of the oil cylinder through the slider seat and the shift block. Therefore, during the injection molding process, the oil cylinder needs to withstand the pressure exerted by the plastic melt on the oblique core puller. At this time, if the pressure of the plastic melt is too high, it will cause the piston rod of the oil cylinder to be subjected to excessive pressure, which may easily cause the piston rod to retreat due to excessive force, thereby failing to achieve the locking effect, and eventually causing the mold production to fail. Therefore, the core puller mechanism has the problem of insufficient reliability.

[0005] 2. There is a possibility of misoperation during operation, and the mold action sequence may be wrong, that is, the injection molding machine may be opened without the oblique core being pulled out, resulting in serious consequences such as damage to the mold or damage to the product during the mold opening process. If the oil cylinder resets the oblique core before the injection molding machine closes the mold, and then the injection molding machine closes the mold, the mold may be damaged. Summary of the invention

[0006] The purpose of the present invention is to solve the above problems in the prior art and to propose a core pulling mechanism for an injection mold. The present invention solves the problem of insufficient reliability of the prior core pulling mechanism.

[0007] The objectives of the present invention can be achieved through the following technical solutions: a core pulling mechanism of an injection mold, the injection mold includes a fixed mold and a movable mold located below the fixed mold, a core pulling slider that can extend into the mold cavity is slidably arranged in the fixed mold, and is characterized in that the core pulling mechanism includes a pull rod that is arranged on the fixed mold and can move downward relative to the fixed mold, and when the pull rod moves downward, it can drive the core pulling slider to slide out of the mold cavity, and a positioning groove is provided on the outer wall of the pull rod; a locking assembly with a plug-in hole is provided on the movable mold and is located below the pull rod, and the lower end of the pull rod is slidably inserted into the plug-in hole, and a locking ball and an elastic member are provided in the locking assembly, and the locking ball can be partially extended into the plug-in hole under the action of the elastic member and be engaged with the positioning groove on the pull rod. The core pulling mechanism also includes a driving assembly that can drive the locking assembly to move downward relative to the movable mold.

[0008] The working principle of this core pulling mechanism is as follows: when the injection molding is completed and the mold needs to be opened, before the fixed mold and the movable mold open to each other, the driving assembly first drives the locking assembly to move downward relative to the movable mold. At this time, the locking ball is partially extended into the plug-in hole by the elastic member and is engaged with the positioning slot on the pull rod, so that the pull rod and the locking assembly are locked with each other. Therefore, in the process of the locking assembly moving downward, the pull rod will move downward together, and when the pull rod moves downward, it can drive the core pulling slider to slide out of the mold cavity, thereby realizing the core pulling and demolding of the core pulling slider.

[0009] Afterwards, the fixed mold and the movable mold are opened to each other again. During the mold opening process, since the outer wall of the locking ball is a spherical surface and partially extends into the positioning slot, when the locking assembly on the movable mold moves downward with the movable mold, the lower slot wall of the positioning slot will force the locking ball to be pushed out radially outward, so that the elastic part is compressed, and finally the locking ball will fall out of the positioning slot of the pull rod, so that the locking state formed by the pull rod and the locking assembly is released, and finally the pull rod can be separated from the locking assembly as a whole, ensuring that the fixed mold and the movable mold can be opened smoothly.

[0010] Therefore, the core pulling mechanism is provided with a driving component, so that before the movable mold and the fixed mold are opened to each other, the pull rod can be driven to move downward to pull the core of the core pulling slider to demold, so as to avoid the problems of pulling the mold and the product during the mold opening process, thereby improving the reliability of the core pulling mechanism and the mold. In addition, the core pulling mechanism is provided with a pull rod and a locking component, and relies on the elastic action of the elastic member to push the locking ball, so that the locking ball is engaged with the positioning slot on the pull rod, so as to achieve the locking of the pull rod and the locking component. In this way, it can ensure that the driving component can smoothly drive the pull rod to move downward to realize the core pulling of the core pulling slider to demold, and at the same time, it can avoid the problem that when the oil cylinder is used to directly drive the core pulling slider to move for core pulling, it is easy to cause the plastic melt to apply too much pressure to the oil cylinder, causing the oil cylinder piston to retreat. Therefore, the core pulling mechanism has good working reliability.

[0011] In the core pulling mechanism of the above-mentioned injection mold, the locking assembly includes an inner core which is cylindrical and has the plug-in hole formed therein, and the side wall of the inner core is provided with a plurality of positioning holes along the circumferential direction, and a locking ball is provided in each positioning hole. The design of arranging a plurality of locking balls circumferentially makes the locking force evenly distributed, which is conducive to ensuring that the pull rod and the plug-in hole always maintain a good concentric fit, and improves the stability of the pull rod during the movement of the plug-in hole. In addition, the provision of multiple locking balls can also enhance the locking force, so that the locking ball has a better locking effect when it is engaged in the positioning slot of the pull rod, ensuring that the locking assembly can stably move the pull rod downward during the downward movement, thereby more stably realizing the core pulling and demoulding of the core pulling slider, and improving the working reliability of the core pulling mechanism.

[0012] In the core pulling mechanism of the above-mentioned injection mold, the driving assembly includes a sliding locking block that is vertically slidably arranged on the movable mold and a bottom plate that is located below the movable mold and fixedly connected to the sliding locking block. The inner core of the locking assembly is fixedly connected to the upper end of the sliding locking block. A parting spring that presses the bottom plate downward so that the bottom plate can move downward relative to the movable mold is provided between the bottom plate and the movable mold. When the injection molding is completed and the mold needs to be opened, the first parting surface between the bottom plate and the movable mold will be opened first due to the action of the parting spring. At this time, the bottom plate moves downward with the sliding locking block and the locking assembly, and then moves downward with the pull rod to realize the core pulling and demolding of the core pulling slider. In this process, the action of the parting spring can ensure that the core pulling action has been performed on the core pulling slider before the second parting surface between the movable mold and the fixed mold is opened, thereby avoiding the possibility of misoperation in the prior art described in the background technology, and solving the problem of damaging the mold or product during the mold opening process due to the disorder of the mold action sequence.

[0013] In the core-pulling mechanism of the injection mold described above, the locking assembly also includes an outer sleeve that is slidably sleeved on the outside of the inner core, and an escape groove that can accommodate the locking ball is opened circumferentially on the inner wall of the outer sleeve, and the lower groove wall of the positioning slot is a first push slope that is set toward the locking ball, and the lower groove wall of the escape groove is a second push slope that is set toward the locking ball, and the elastic member can push the outer sleeve to move upward and rely on the second push slope to resist the locking ball so that the locking ball in the positioning hole is engaged with the positioning slot. By setting the escape groove circumferentially on the outer sleeve, and the lower groove wall of the escape groove is the inclined second push slope, the outer sleeve can simultaneously push each locking ball, ensuring that the locking ball has a better locking effect when it is engaged in the positioning slot of the pull rod. In addition, the lower groove wall of the positioning groove is a push slope 1 set toward the locking ball. When the fixed mold and the movable mold are opened to each other, the push slope 1 can better push the locking ball to move radially outward, and then each locking ball can push the push slope 2 at the same time, so that the outer shell is subjected to uniform push force in the circumferential direction, and then can stably move downward relative to the inner core, so that each locking ball can smoothly enter the avoidance groove, and finally realize the release of the locking state of the pull rod and the locking assembly, thereby smoothly realizing the separation of the movable mold and the fixed mold.

[0014] In the core-pulling mechanism of the above-mentioned injection mold, the elastic member is a spring, the outer wall of the inner core has an annular boss arranged along the circumferential direction, the lower end surface of the outer shell is provided with a step hole plugged with the annular boss, the step surface of the step hole is directly opposite to the upper end surface of the annular boss, and the upper end surface of the annular boss is provided with a plurality of mounting holes along the circumferential direction, and the mounting holes are respectively provided with elastic members, and the upper end of the elastic member is against the step surface. The elastic member is arranged in the mounting hole, so that the elastic member has good stability and can better push the outer shell upward. The step hole is plugged with the annular boss, which can form a guide for the movement of the outer shell, so that the outer shell can stably move up and down relative to the inner core. By arranging multiple elastic members along the circumferential direction on the annular boss, the outer shell is subjected to uniform elastic force in the circumferential direction and the outer shell can also be subjected to a large elastic force, so that the outer shell can simultaneously form a better pushing effect on each locking ball, and then the locking ball has a better locking effect when it is connected to the positioning card slot of the pull rod.

[0015] In the core pulling mechanism of the above-mentioned injection mold, a guide hole is vertically opened on the upper edge of the movable mold, the sliding lock block is slidably arranged in the guide hole, and the lower end of the sliding lock block is fixedly connected to the bottom plate. By setting the guide hole and the lower end of the sliding lock block being fixedly connected to the bottom plate, when the first parting surface between the bottom plate and the movable mold is opened under the action of the parting spring, it can ensure that the sliding lock block moves downward stably, thereby driving the locking assembly and the pull rod to move downward to realize the core pulling and demoulding of the core pulling slider. The lower end of the inner core is connected to the upper end of the sliding lock block by a fastening bolt.

[0016] In the core-pulling mechanism of the above-mentioned injection mold, the lower end of the pull rod is in a cone head shape.

[0017] When the mold is in the open state, the pull rod as a whole will be out of the plug hole of the inner core, and when the mold needs to be closed for injection molding, the bottom plate pushes the movable mold upward, and the lower end of the pull rod will be inserted into the plug hole, and then the lower end of the pull rod will contact the locking ball. At this time, since the lower end of the pull rod is in the shape of a cone, it can push the locking ball to move radially outward. During the movement, the locking ball will push the second push slope on the outer shell, and finally the locking ball will be squeezed into the avoidance groove of the outer shell, ensuring that the pull rod can continue to be inserted into the plug hole of the inner core. During the insertion process, when the locking ball and the positioning slot at the lower end of the pull rod are at the same height, the locking ball can move radially inward under the action of the elastic member and engage with the positioning slot on the pull rod, so that the pull rod and the locking assembly are reset to the locked state.

[0018] In the core-pulling mechanism of the injection mold, an annular groove is provided on the outer wall of the upper end of the inner core, and a limit clamp spring is clamped in the annular groove and can abut against the upper end surface of the outer shell. When assembling the locking assembly, the outer shell is first sleeved on the outer core, and then the limit clamp spring is clamped in the annular groove to complete the assembly between the two, which is very convenient.

[0019] In the core pulling mechanism of the above-mentioned injection mold, a distance screw is vertically penetrated on the bottom plate, and the rod of the distance screw passes upward through the bottom plate and is threadedly connected to the movable mold. The bottom plate has a limiting surface located above the head of the distance screw. When the parting spring pushes the bottom plate to move downward, the limiting surface can abut against the head of the distance screw. When the first parting surface between the bottom plate and the movable mold is opened, the limiting surface will abut against the head of the distance screw, thereby limiting the opening distance of the first parting surface. Since the opening distance of the first parting surface is limited, when the bottom plate continues to move downward, it can move the movable mold downward through the bottom plate, thereby realizing the opening of the second parting surface between the movable mold and the fixed mold.

[0020] In the core pulling mechanism of the injection mold, the driving assembly is a driving screw that is vertically arranged and threadedly connected to the sliding lock block, and a driving motor that can drive the driving screw to rotate, and the driving motor is fixedly connected to the movable mold.

[0021] Before the movable mold and the fixed mold are opened, the driving motor drives the driving screw to rotate, so that the sliding lock block moves downward, and then drives the locking assembly and the pull rod to move downward to realize the core-pulling slider core-pulling demoulding. After the core-pulling slider core-pulling demoulding is completed, the movable mold and the fixed mold are opened again to take out the injection molded product.

[0022] Compared with the prior art, the core pulling mechanism of the injection mold has the following advantages:

[0023] 1. The core pulling mechanism is provided with a pull rod and a locking assembly, and relies on the elastic action of the elastic member to push the locking ball, so that the locking ball is engaged with the positioning groove on the pull rod, thereby locking the pull rod and the locking assembly. In this way, it can avoid the problem that when the oil cylinder is used to directly drive the core pulling slider to move for core pulling, the plastic melt may apply too much pressure to the oil cylinder, causing the oil cylinder piston to retreat. Therefore, the core pulling mechanism has good working reliability.

[0024] 2. When the mold needs to be opened after injection molding is completed, the first parting surface between the bottom plate and the movable mold will be opened first due to the action of the parting spring, ensuring that the core pulling action is performed on the core pulling slider before the second parting surface between the movable mold and the fixed mold is opened, thereby avoiding the possibility of misoperation in the prior art described in the background technology, and solving the problem of damaging the mold or product during the mold opening process due to the disorder of the mold action sequence. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a partial cross-sectional view of the mold.

[0026] Figure 2 yes Figure 1 Enlarged view of point A in the middle.

[0027] Figure 3 Schematic diagram of the pull rod and locking assembly in the unlocked state.

[0028] Figure 4 It is a partial cross-sectional view of the mold after the first parting surface between the base plate and the movable mold is opened.

[0029] Figure 5 It is a schematic diagram of the three-dimensional structure of the inner core.

[0030] Figure 6 It is a cross-sectional view of the inner core.

[0031] Figure 7 It is a three-dimensional structural diagram of the pull rod.

[0032] Figure 8 This is a partial cross-sectional view of the limit screw of the mold

[0033] Fig. 9 It is an exploded view of the core-pulling slider and the T-type slider.

[0034] In the figure, 1, fixed mold; 2, movable mold; 2a, guide hole; 3, mold cavity; 4, core-pulling slider; 41, inclined guide groove; 5, pull rod; 51, positioning slot; 511, push ramp 1; 6, locking assembly; 61, inner core; 611, plug-in hole; 612, positioning hole; 613, annular boss; 614, mounting hole; 615, annular slot; 62, outer shell; 621, avoidance groove; 621a, push ramp 2; 622, step hole; 622a, step surface; 7, locking ball; 8, elastic member; 9, sliding lock block; 10, bottom plate; 101, limit surface; 11, parting spring; 12, limit retaining spring; 13, fixed distance screw; 14, T-type slider; 15, limit screw. DETAILED DESCRIPTION

[0035] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0036] Embodiment 1

[0037] like Figure 1 As shown, the injection mold includes a fixed mold 1 and a movable mold 2 located below the fixed mold 1. When the movable mold 2 and the fixed mold 1 are in a mold-clamping state, a mold cavity 3 is formed between the two. A core-pulling slider 4 that can extend into the mold cavity 3 is provided in the fixed mold 1 along the horizontal direction, and a T-shaped slider 14 is also provided in the fixed mold 1 along the vertical direction. Fig. 9 As shown, the core-pulling slider 4 has an oblique guide groove 41, which is slidably connected to the T-shaped slider 14, so that when the T-shaped slider 14 moves downward, it can drive the core-pulling slider 4 to move horizontally to enable the core-pulling slider 4 to slide out of the mold cavity 3.

[0038] like Figure 1 and Figure 2 As shown, the core pulling mechanism includes a pull rod 5 which is arranged on the fixed mold 1 and can move downward relative to the fixed mold 1, combined with Figure 7 As shown, the lower end of the pull rod 5 is in a cone shape, and the upper end of the pull rod 5 is fixedly connected to the T-shaped slider 14. Therefore, when the pull rod 5 moves downward, it can drive the T-shaped slider 14 to move downward, and then drive the core-pulling slider 4 to move horizontally to slide out of the mold cavity 3, and finally realize the core-pulling demolding of the core-pulling slider 4.

[0039] Further, such as Figure 1 and Figure 2As shown, a positioning slot 51 is provided on the outer wall of the pull rod 5; a locking assembly 6 with a plug-in hole 611 located below the pull rod 5 is provided on the movable mold 2, and the lower end of the pull rod 5 is slidably plugged into the plug-in hole 611, and a locking ball 7 and an elastic member 8 are provided in the locking assembly 6. The lower groove wall of the positioning slot 51 is a push slope 511 set toward the locking ball 7. The locking ball 7 can be partially extended into the plug-in hole 611 and plugged with the positioning slot 51 on the pull rod 5 under the action of the elastic member 8. The core pulling mechanism also includes a driving assembly that can drive the locking assembly 6 to move downward relative to the movable mold 2.

[0040] like Figure 1 As shown, the driving assembly includes a sliding lock block 9 that is vertically slidably penetrated on the movable mold 2 and a bottom plate 10 that is located below the movable mold 2 and fixedly connected to the sliding lock block 9. The bottom plate 10 is connected to the hydraulic drive mechanism of the injection mold, so that the hydraulic drive mechanism can drive the bottom plate 10 to move up and down to realize the opening and closing of the injection mold. The locking assembly 6 is fixedly connected to the upper end of the sliding lock block 9, and a parting spring 11 is provided between the bottom plate 10 and the movable mold 2 to press the bottom plate 10 downward so that the bottom plate 10 can move downward relative to the movable mold 2. A fixed-distance screw 13 is vertically penetrated on the bottom plate 10, and the rod of the fixed-distance screw 13 passes through the bottom plate 10 upward and is threadedly connected to the movable mold 2. The bottom plate 10 has a limiting surface 101 located above the head of the fixed-distance screw 13. When the parting spring 11 pushes the bottom plate 10 to move downward, the limiting surface 101 can abut against the head of the fixed-distance screw 13. When the first parting surface between the bottom plate 10 and the movable mold 2 is opened, the limiting surface 101 will abut against the head of the fixed-distance screw 13, thereby limiting the opening distance of the first parting surface.

[0041] like Figure 2 and Figure 5 As shown, the locking ball 7 is a steel ball, and the locking assembly 6 includes an inner core 61 which is cylindrical and has an inserting hole 611 formed therein. The side wall of the inner core 61 is provided with a plurality of positioning holes 612 along the circumferential direction, and each positioning hole 612 is provided with a locking ball 7. Figure 6 As shown, the outer opening of the positioning hole 612 is larger than the inner opening, and the outer opening is larger than the diameter of the locking ball 7, ensuring that the locking ball 7 can enter the positioning hole 612, while the inner opening is smaller than the diameter of the locking ball 7, ensuring that when the pull rod 5 is completely disengaged from the plug-in hole 611, the locking ball 7 will not be disengaged from the positioning hole 612. The locking assembly 6 also includes an outer sleeve 62 slidably sleeved on the outside of the inner core 61, and an escape groove 621 that can accommodate the locking ball 7 is circumferentially provided on the inner wall of the outer sleeve 62, and the lower groove wall of the escape groove 621 is a second push slope 621a arranged toward the locking ball 7, and the elastic member 8 can push the outer sleeve 62 to move upward and rely on the second push slope 621a to resist the locking ball 7 so that the locking ball 7 in the positioning hole 612 is engaged with the positioning slot 51.

[0042] like Figure 2 and Figure 5 As shown, the elastic member 8 is a spring, and the outer wall of the inner core 61 is provided with an annular boss 613 arranged along the circumferential direction. The lower end surface of the outer shell 62 is provided with a step hole 622 which is plugged into the annular boss 613. The step surface 622a of the step hole 622 is directly opposite to the upper end surface of the annular boss 613. The upper end surface of the annular boss 613 is provided with a plurality of mounting holes 614 along the circumferential direction. The elastic members 8 are respectively arranged in the mounting holes 614, and the upper end of the elastic member 8 is abutted against the step surface 622a.

[0043] like Figure 1 As shown, a guide hole 2a is vertically provided on the upper edge of the movable mold 2, and a sliding lock block 9 is slidably arranged in the guide hole 2a, and the lower end of the sliding lock block 9 is fixedly connected to the bottom plate 10. By providing the guide hole 2a and the lower end of the sliding lock block 9 being fixedly connected to the bottom plate 10, when the first parting surface between the bottom plate 10 and the movable mold 2 is opened under the action of the parting spring 11, it can ensure that the sliding lock block 9 moves downward stably, thereby driving the locking assembly 6 and the pull rod 5 to move downward to realize the core pulling and demoulding of the core pulling slider 4.

[0044] like Figure 2 and Figure 5 As shown, an annular groove 615 is provided on the outer wall of the upper end of the inner core 61, and a limit clamping spring 12 that can abut against the upper end surface of the outer shell 62 is clamped in the annular groove 615, and the lower end of the inner core 61 is fixedly connected to the upper end of the sliding lock block 9 by a fastening bolt. When assembling the locking assembly 6, the outer shell 62 is first sleeved on the outside of the inner core 61, and then the limit clamping spring 12 is clamped in the annular groove 615, and the assembly between the two can be completed, and the assembly is very convenient.

[0045] The working principle of this core pulling mechanism is introduced below:

[0046] Mould opening:

[0047] When the injection molding is completed and the mold needs to be opened, Figure 3 As shown, the parting spring 11 causes the first parting surface between the bottom plate 10 and the movable mold 2 to open first. At this time, the bottom plate 10 moves downward with the sliding lock block 9 and the locking assembly 6 until the limit surface 101 on the bottom plate 10 abuts against the head of the fixed-distance screw 13, and the first parting surface is opened. In this process, the locking ball 7 in the locking assembly 6 remains in a state of being engaged with the positioning slot 51, so that the locking assembly 6 and the pull rod 5 are locked, and the sliding lock block 9 will move downward with the pull rod 5, and then the T-shaped slider 14 moves downward with the sliding lock block 9. At this time, since the T-shaped slider 14 is slidably connected with the oblique guide groove 41 on the core-pulling slider 4, and the T-shaped slider 14 is a structure that is narrow at the top and wide at the bottom, when the T-shaped slider 14 moves downward, a space for the core-pulling slider 4 to move horizontally can be formed at the top, so that the core-pulling slider 4 will move horizontally to slide out of the mold cavity 3, and finally the core-pulling slider 4 is demoulded.

[0048] After the core-pulling slider 4 is stripped, the hydraulic drive mechanism of the injection mold continues to move downward with the bottom plate 10. At this time, since the limit surface 101 on the bottom plate 10 abuts against the head of the fixed-distance screw 13 after the first parting surface is opened, the bottom plate 10 can move downward with the movable mold 2 when moving downward, so that the second parting surface between the fixed mold 1 and the movable mold 2 begins to open. At this time, Figure 8 As shown, since the setting of the limit screw 15 can limit the downward movement stroke of the T-shaped slider 14, the pull rod 5 will not move downward with the movable mold 2 during the downward movement of the movable mold 2. During the mutual opening of the fixed mold 1 and the movable mold 2, the sliding lock block 9 moves downward with the movable mold 2 and drives the locking assembly 6 to move downward. At this time, since the lower groove wall of the positioning groove 51 is a push slope 511 inclined toward the locking ball 7, the push slope 511 will force the locking ball 7 to be pushed outward radially during the downward movement of the locking assembly 6 with the movable mold 2, and the locking ball 7 pushes the push slope 2 621a on the outer sleeve 62, so that the outer sleeve 62 compresses the elastic member 8 and moves downward relative to the inner core 61, as shown in FIG. Figure 4 As shown, the locking ball 7 will eventually escape from the positioning slot 51 of the pull rod 5 and enter the avoidance groove 621, so that the locking state formed by the pull rod 5 and the locking assembly 6 is released. As the movable mold 2 continues to move downward, the pull rod 5 can be completely separated from the locking assembly 6, ensuring that the fixed mold 1 and the movable mold 2 can be opened smoothly.

[0049] Mould closing:

[0050] When the mold is in the open mold state, the pull rod 5 is completely out of the insertion hole 611 of the inner core 61. When the mold needs to be closed for injection molding, the hydraulic drive mechanism moves the bottom plate 10 upward, so that the bottom plate 10 pushes the movable mold 2 upward, and the lower end of the pull rod 5 is inserted into the insertion hole 611, and then the lower end of the pull rod 5 contacts the locking ball 7. At this time, since the lower end of the pull rod 5 is in the shape of a cone head, it can push the locking ball 7 to move radially outward. During the movement, the locking ball 7 will push the pushing inclined surface 621a on the outer shell 62, and finally the locking ball 7 will be squeezed into the avoidance groove 621 of the outer shell 62, ensuring that the pull rod 5 can continue to be inserted into the insertion hole 611 of the inner core 61. During the insertion process, when the locking ball 7 and the positioning slot 51 at the lower end of the pull rod 5 are at the same height, the locking ball 7 can move radially inward under the action of the elastic member 8 and engage with the positioning slot 51 on the pull rod 5, so that the pull rod 5 and the locking assembly 6 are reset to the state as shown. Figure 1 Lock status shown.

[0051] Embodiment 2

[0052] The principles of this embodiment are basically the same as those of the first embodiment. At the same time, the locking assembly 6 adopts the same structure as that of the first embodiment, and also includes an inner core 61 and an outer sleeve 62. The difference lies in the structure of the driving assembly. Specifically, in this embodiment, the driving assembly includes a sliding locking block 9 that is vertically slidably arranged on the movable mold 2 and a driving motor that is fixedly connected to the movable mold 2. A driving screw that is coaxially arranged with the sliding locking block 9 is connected to the rotating shaft of the driving motor, and the driving screw is threadedly connected to the sliding locking block 9. The inner core 61 of the locking assembly 6 is fixedly connected to the upper end of the sliding locking block 9.

[0053] In this embodiment, the hydraulic drive mechanism of the injection mold is connected to the movable mold 2. Before the movable mold 2 and the fixed mold 1 are opened, the driving motor drives the driving screw to rotate, so that the sliding lock block 9 moves downward, and then drives the inner core 61 of the locking assembly 6 and the pull rod 5 to move downward to realize the core pulling and demoulding of the core pulling slider 4. After the core pulling and demoulding of the core pulling slider 4 are completed, the hydraulic drive mechanism drives the movable mold 2 to move downward again, so that the movable mold 2 and the fixed mold 1 are opened, and the injection molded product is taken out.

[0054] The specific embodiments described herein are merely examples of the spirit of the present invention. A person skilled in the art of the present invention may make various modifications or additions to the specific embodiments described, or replace them in a similar manner, but this will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims. In the present injection mold, the movable mold 2 and the fixed mold 1 may be arranged in an upper and lower manner. In the actual production process, the movable mold 2 and the fixed mold 1 may also be arranged in a horizontal direction in the left and right directions.

[0055] Although this article uses the terms 1. fixed mold; 2. movable mold; 2a. guide hole; 3. mold cavity; 4. core-pulling slider; 5. pull rod; 51. positioning slot; 511. push ramp 1; 6. locking assembly; 61. inner core; 611. plug-in hole; 612. positioning hole; 613. annular boss; 614. mounting hole; 615. annular slot; 62. outer shell; 621. avoidance groove; 621a. push ramp 2; 622. step hole; 622a. step surface; 7. locking ball; 8. elastic member; 9. sliding lock block; 10. bottom plate; 101. limit surface; 11. parting spring; 12. limit retaining spring; 13. fixed distance screw; 14. T-type slider; 15. limit screw, etc., the possibility of using other terms is not excluded. These terms are used only to more conveniently describe and explain the essence of the present invention; any additional limitations interpreted as them are contrary to the spirit of the present invention.

Claims

1. A core pulling mechanism for an injection mold, the injection mold comprising a fixed mold (1) and a movable mold (2) located below the fixed mold (1), the fixed mold (1) being provided with a core pulling slider (4) capable of extending into a mold cavity (3), characterized in that: The core pulling mechanism comprises a pull rod (5) which is arranged on the fixed mold (1) and can move downward relative to the fixed mold (1), and when the pull rod (5) moves downward, it can drive the core pulling slider (4) to slide out of the mold cavity (3), and a positioning groove (51) is opened on the outer wall of the pull rod (5). The movable mold (2) is provided with a locking component (6) with a plug hole (611) located below the pull rod (5), and the lower end of the pull rod (5) is slidably plugged into the plug hole (611). The locking component (6) is provided with a locking ball (7) and an elastic member (8). The locking ball (7) can be partially extended into the plug hole (611) and be plugged into the positioning groove (51) on the pull rod (5) under the action of the elastic member (8). The core pulling mechanism also comprises a driving component which can drive the locking component (6) to move downward relative to the movable mold (2).

2. The core-pulling mechanism of the injection mold according to claim 1, characterized in that: The locking assembly (6) comprises an inner core (61) which is cylindrical and has the insertion hole (611) formed therein. The side wall of the inner core (61) is provided with a plurality of positioning holes (612) along the circumferential direction. A locking ball (7) is arranged in each positioning hole (612).

3. The core-pulling mechanism of the injection mold according to claim 2, characterized in that: The driving assembly comprises a sliding lock block (9) which is vertically slidably disposed on the movable mold (2) and a bottom plate (10) which is located below the movable mold (2) and fixedly connected to the sliding lock block (9); an inner core (61) of the locking assembly (6) is fixedly connected to the upper end of the sliding lock block (9); and a parting spring (11) which presses the bottom plate (10) downwardly and enables the bottom plate (10) to move downwardly relative to the movable mold (2) is provided between the bottom plate (10) and the movable mold (2).

4. The core-pulling mechanism of the injection mold according to claim 3, characterized in that: The locking assembly (6) further comprises an outer sleeve (62) slidably sleeved on the outside of the inner core (61); an escape groove (621) capable of accommodating the locking ball (7) is circumferentially provided on the inner wall of the outer sleeve (62); a lower groove wall of the positioning slot (51) is a first pushing inclined surface (511) arranged toward the locking ball (7); a lower groove wall of the escape groove (621) is a second pushing inclined surface (621a) arranged toward the locking ball (7); the elastic member (8) can push the outer sleeve (62) to move upward and rely on the second pushing inclined surface (621a) to press against the locking ball (7) so that the locking ball (7) in the positioning hole (612) is engaged with the positioning slot (51).

5. The core-pulling mechanism of the injection mold according to claim 4, characterized in that: The elastic member (8) is a spring. The outer wall of the inner core (61) is provided with an annular boss (613) arranged in the circumferential direction. The lower end surface of the outer shell (62) is provided with a step hole (622) which is plugged into and matched with the annular boss (613). The step surface (622a) of the step hole (622) is directly opposite to the upper end surface of the annular boss (613) in the upper end surface. A plurality of mounting holes (614) are provided in the upper end surface of the annular boss (613) in the circumferential direction. The elastic members (8) are respectively arranged in the mounting holes (614), and the upper end of the elastic member (8) abuts against the step surface (622a).

6. The core-pulling mechanism of the injection mold according to claim 3, 4 or 5, characterized in that: A guide hole (2a) is vertically opened on the upper edge of the movable mold (2), the sliding lock block (9) is slidably arranged in the guide hole (2a), and the lower end of the sliding lock block (9) is fixedly connected to the bottom plate (10).

7. The core pulling mechanism of the injection mold according to any one of claims 1 to 5, characterized in that: The lower end of the pull rod (5) is in the shape of a cone.

8. The core-pulling mechanism of the injection mold according to claim 4 or 5, characterized in that: An annular clamping groove (615) is provided on the outer wall of the upper end of the inner core (61), and a limit clamping spring (12) capable of abutting against the upper end surface of the outer shell (62) is clamped in the annular clamping groove (615).

9. The core pulling mechanism of the injection mold according to any one of claims 3 to 5, characterized in that: A fixed-distance screw (13) is vertically penetrated on the bottom plate (10), and the rod portion of the fixed-distance screw (13) passes through the bottom plate (10) upwards and is threadedly connected to the movable mold (2). The bottom plate (10) has a limiting surface (101) located above the head of the fixed-distance screw (13), and when the parting spring (11) pushes the bottom plate (10) to move downward, the limiting surface (101) can abut against the head of the fixed-distance screw (13).

10. The core-pulling mechanism of the injection mold according to claim 2, characterized in that: The driving assembly comprises a sliding lock block (9) vertically slidably inserted into the movable mold (2) and a driving motor fixedly connected to the movable mold (2); a driving screw rod coaxially arranged with the sliding lock block (9) is connected to the rotating shaft of the driving motor, and the driving screw rod is threadedly connected to the sliding lock block (9); and an inner core (61) of the locking assembly (6) is fixedly connected to the upper end of the sliding lock block (9).

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