Plastic part injection mold
By designing fixing plates, lifting components and connecting components in plastic parts injection molds, combining flow guides and segmented structures to lift rods, small size and irregular shapes are solved due to excessive pressure during the release process of products with small size and irregular shapes. The problem of white top or concave top achieves stable, smooth mold release and high-quality finished products of plastic parts.
Patent Information
- Application Number
- CN202411356296.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-27
- Publication Date
- 2025-01-03
AI Technical Summary
During the mold release process of plastic parts injection molds, products with smaller volume and irregular shapes are too high due to the excessive pressure between the top rod and the plastic parts, resulting in white or concave surfaces of the plastic parts, affecting product quality.
A plastic injection mold including a fixing plate, a lifting assembly and a connecting assembly is designed. The lifting rod is driven to rise through the lifting plate. The lifting rod shrinks during the pressing process, and the use of the flow guide and coolant is used to reduce the lifting. The rod temperature reduces the release stress, and the lifting force is buffered through the sectioned structure's top rod and spring device to ensure the stable release of the plastic parts.
It effectively avoids deformation and quality problems caused by stress concentration during the release process of plastic parts, improves product integrity and production efficiency, and ensures high-quality release of plastic parts.
Smart Images
Figure CN119238874A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of injection molds, and in particular to a plastic part injection mold. Background Art
[0002] An injection mold for plastic parts is a molding tool used to produce plastic products. Injection molds can quickly and mass-produce products of the same specifications, and are an indispensable key tool in the production process of plastic products. Injection molds usually include a male mold plate, a female mold plate, a fixing plate, a cooling system, and a discharge system. During use, the preheated plastic raw material is injected into the mold cavity formed by the male mold plate and the female mold plate. After the plastic is cooled and formed in the mold cavity, the molded plastic product is ejected from the mold through the ejector.
[0003] After the plastic injection mold is cooled and formed, the plastic product in the mold cavity needs to be taken out. During the demolding process, it is usually necessary to use a lifter to eject the molded plastic product. In this process, due to the small contact area between the lifter and the plastic part, the ejection speed is too fast or the demolding pressure is too high, the surface of the plastic part will be whitened, and even the plastic part will crack, affecting the product quality. The prior art has proposed a good solution to this problem, such as a laminated lifter anti-whitening bucket injection mold with patent publication number CN109878041B. By increasing the contact area between the lifter and the plastic part and making the lifter carry a rotational force during the lifting process, it will not adhere to the molded plastic part. In addition, due to the increase in the contact area, the lifter force can be distributed to ensure that the plastic part will not be subjected to excessive pressure, resulting in whitening and cracking, so that the plastic part can be completely demolded to ensure the quality of the plastic part.
[0004] Although the prior art solves the problem that the plastic parts are subjected to a large lifting pressure due to the small contact area between the plastic parts and the lifting parts, resulting in whitening and cracking, the following problems still exist: for products with small volume and irregular shape, it is impossible to reduce the pressure by increasing the contact area during lifting, and the mold can only be demolded by using a small diameter ejector rod. At this time, a large pressure will still be applied to the surface of the plastic parts, resulting in whitening or concave phenomena on the surface of the plastic parts, thereby reducing the quality of the plastic parts.
[0005] In view of the above situation, in order to overcome the above technical problems, the present invention designs a plastic part injection mold. Summary of the invention
[0006] The present invention provides a plastic part injection mold, which solves the problem that the surface quality of the finished plastic part is low due to the strong pressure between the plastic part and the ejector pin during the demolding process of a product with a small volume and an irregular shape. When the ejector pin presses the plastic part, the plastic part is fixed and the force applied to the plastic part is gradually increased, thereby avoiding deformation of the surface of the plastic part caused by excessive pressure at the moment, and making the ejection process change from slow to fast and then to slow again, thereby reducing the influence of vacuum negative pressure on the plastic part and ensuring the demolding quality of the plastic part.
[0007] To achieve the above object, the present invention provides the following technical solutions:
[0008] A plastic part injection mold comprises an injection hole, a male mold plate, a female mold plate and a cooling component; further comprising a fixing plate, a lifting component and a connecting component; the fixing plate comprises an upper fixing plate and a lower fixing plate; the lifting component is connected to the lower fixing plate; the connecting component is connected between the upper fixing plate and the lifting component; the upper fixing plate and the female mold plate are lifted upward, the upper fixing plate rises to drive the connecting component to rotate, the connecting component rotates to drive the lifting component to rise at a speed slower than the upper fixing plate, the lifting component rises to press the plastic part, the lifting component shrinks during the pressing process, and when the plastic part is separated from the male mold plate, the lifting component recovers and quickly ejects the plastic part.
[0009] Preferably, the lifting assembly includes a guide column, a top plate, a rising groove, a push rod and a guide piece; the guide column is connected between the lower fixed plate and the male template; the top plate is slidably mounted on the guide column; the push rod is connected to the top plate; the rising groove is opened inside the male template, and a limiting ring is provided at the upper end of the rising groove; the diameter of the limiting ring is smaller than the diameter of the upper end of the push rod; the guide piece is connected to the cooling assembly.
[0010] In the above scheme, the rise of the top plate can drive the ejector rod to rise, thereby realizing the lifting movement; the limit ring can ensure that the ejector rod will not slide downward under the high-pressure working environment, thereby preventing the melted plastic from entering the rising groove; the coolant in the cooling assembly is guided by the guide piece to connect with the ejector rod, thereby reducing the surface of the ejector rod to the optimal demolding temperature, thereby preventing the ejector rod and the plastic part from sticking together.
[0011] Preferably, the guide member includes a guide groove, a pressure piston, a cooling groove and a drainage groove; the guide groove is connected to the cooling assembly; the pressure piston is connected to the push rod; the cooling groove is opened on the outer ring of the push rod; the drainage groove is connected to the cooling groove.
[0012] In the above scheme, during the lifting process, the low-temperature coolant can be directed to the position of the ejector pin to assist in demolding, and the ejector pin can be lowered to a reasonable demolding temperature, thereby reducing the demolding stress and avoiding deformation of the plastic part due to stress concentration; during the cooling process, the coolant will not reach the position of the ejector pin, thereby avoiding deformation of the plastic part due to uneven cooling during the cooling process.
[0013] Preferably, the push rod includes a contact end, a sliding end, a spring pin and a top pressure spring; the contact end is connected to the male template, and the contact end matches the shape of the bottom surface of the male template; the sliding end is connected to the top plate; the spring pin is connected to the sliding end, and a gap is maintained between the spring pin and the contact end; the top pressure spring is sleeved on the spring pin and connected between the sliding end and the contact end.
[0014] In the above scheme, the push rod is designed to be a segmented structure, so that when the push rod is pushed upward, the push spring is first compressed during the force process, and then the force is transmitted to the plastic part through the push spring. The force is deformed by the spring to form a buffer for the plastic part, thereby avoiding damage to the plastic part. The spring pin can prevent the push spring from radially deforming during the lifting process, resulting in deviation during the lifting process, thereby ensuring a smooth lifting process; when the push spring is compressed to the point where the spring pin presses against the contact end, the lifting force reaches a maximum, and when the plastic part is separated from the male template, the push spring returns to its original state and will use elastic force to quickly push the plastic part out and separate it from the male template, thereby avoiding too long demolding time for the plastic part, uneven deformation of the plastic part due to cooling and shrinkage, and increasing the clamping force between the male template, thereby causing wear on the surface of the plastic part during the demolding process, and can avoid adhesion between the contact end of the push rod and the plastic part, thereby improving production efficiency; at the same time, the demolding method of slow first and fast later helps to reduce the damage to the plastic part caused by vacuum negative pressure.
[0015] Preferably, the elastic modulus of the connection position between the pressure spring and the contact end is greater than the elastic modulus of the connection position between the pressure spring and the sliding end.
[0016] In the above scheme, by changing the elastic modulus, during the jacking process, when the jacking spring is subjected to the upward jacking force of the sliding end, the part with a small elastic modulus of the jacking spring is deformed first for buffering, so that the jacking force on the plastic part is a gradually increasing process, ensuring that the impact force is reduced when the plastic part is jacked up. For some plastic parts that are easy to deform or have a more complex structure, by slowly increasing the jacking force, they can better adapt to the demoulding process, ensure that the jacking force acts evenly on the plastic part, reduce damage caused by material or structural problems, and make the demoulding process smoother and more reliable; and because the spring pin and the contact end are not directly connected in the initial state, the large elastic modulus of the connection position between the jacking spring and the contact end helps the jacking spring not to undergo radial deformation, and the part with a small elastic modulus of the jacking spring will not undergo radial deformation under the fixation of the spring pin, thereby improving the stability of the jacking process.
[0017] Preferably, the contact end includes a contact block, a contact groove, a contact slider and a contact spring; the contact groove is provided on the contact block; the contact slider is installed in the contact groove; the contact spring is connected between the contact groove and the contact slider; the notch of the rising groove is provided at the edge position of the molding cavity formed by the male template and the female template.
[0018] In the above scheme, during the lifting process of the contact end, the female template removes the pressure on the contact slider. At this time, the contact slider extends higher than the surface of the male template under the action of the spring and fits with the edge of the plastic part, thereby making the plastic part more stable during the demolding process.
[0019] Preferably, the contact slider is made of silicone rubber, and the inner surface of the contact slider is provided with a fitting slope; the fitting slope angle is equal to the demoulding slope α.
[0020] In the above scheme, since the temperature during the injection molding process is generally between 40 and 80 degrees, even if the raw material is polyphenylene sulfide, the mold temperature is below 180 degrees, and silicone rubber can work in an environment of 200 degrees, and after the silicone rubber is bonded to the plastic part, it will not cause wear of the plastic part during the lifting process, and in the process of demolding and removal, the bonding action of the contact slider can ensure that the plastic part will not be directly ejected after demolding is completed, but will reach a position that is convenient for removal, thereby avoiding damage to the plastic part, and the angle of the bonding slope is equal to the demolding slope, ensuring that demolding is carried out at the demolding slope α during the demolding process, making demolding easier, avoiding damage to the plastic part, and ensuring the quality of the plastic part.
[0021] Preferably, the connecting assembly includes a driving rack, a driven rack and a gear set; the driving rack is connected to the upper fixed plate; the driven rack is connected to the top plate; and the gear set is installed between the driving rack and the driven rack.
[0022] In the above scheme, compared with the traditional injection mold, which requires removing the upper fixed plate and the mother template, and then manually lifting the lifting assembly or pressing the male template downward so that the ejector rod lifts the plastic part from the male template to complete demolding, the connecting assembly in this scheme can automatically drive the lifting assembly to move during the process of lifting the upper fixed plate and the mother template upward, drive the gear set to rotate by driving the rack upward, and then drive the driven rack through the gear set to drive the lifting assembly to rise, thereby realizing the lifting function.
[0023] Preferably, the gear set includes a pinion and a gear; the pinion is connected to the driving rack; the gear is connected between the driven rack and the pinion, and the gear ratio between the gear and the pinion is greater than 1.
[0024] In the above scheme, the driving rack is connected to the small gear, the driven rack is connected to the large gear, and the gear ratio of the large gear and the small gear is adjusted to change the lifting speed of the upper fixed plate and the lifting assembly. When the upper fixed plate and the mother template rise to a space position where the mold can be detached, the lifting assembly only lifts a short distance, slowing down the lifting speed of the plastic part, avoiding the whitening phenomenon on the surface of the plastic part caused by too fast a lifting speed, and ensuring the quality of the plastic part; the gear ratio of the large gear and the small gear can be adjusted according to the actual products produced, so as to ensure that neither the ejection is too fast to cause quality degradation, nor the demolding is too slow to reduce production efficiency.
[0025] Preferably, the driven rack includes a telescopic guide groove and a telescopic rack; the telescopic guide groove is connected to the lower fixed plate; a sliding part is provided at the lower part of the telescopic rack; and the sliding part is slidably installed in the telescopic guide groove.
[0026] In the above scheme, when the demolding work is not carried out, the sliding part of the telescopic rack can be retracted in the telescopic guide groove, thereby reducing the structural space, and under the guiding action of the telescopic guide groove, the lifting component can be guided to ensure the stability of the lifting component during the demolding process, thereby ensuring that during the demolding process, the plastic parts will not have a large friction with the side wall of the male template, thereby ensuring the quality of the plastic parts after demolding.
[0027] Compared with the prior art, the present invention has the following beneficial effects:
[0028] 1. Compared with the existing injection mold, the present invention designs the ejector pin into a segmented structure. During the ejection process, the top pressure spring is first compressed during the force-bearing process, and then the force is transmitted to the plastic part through the top pressure spring. The force is deformed by the spring to form a buffer for the plastic part, and the elastic modulus of the top pressure spring is set to be larger at one end and smaller at the other end, so that the ejection force on the plastic part is gradually increased. By slowly increasing the ejection force, the plastic part can better adapt to the demolding process, thereby helping the plastic part to make the demolding process more stable and reliable; after the plastic part is separated from the male mold plate, the plastic part can be quickly bounced upwards by the restoring force of the top pressure spring, so that the demolding process of the plastic part is from slow to fast, which can further avoid the influence of vacuum negative pressure on the quality of the plastic part, thereby ensuring the demolding quality of the plastic part.
[0029] 2. The present invention provides a contact slider at the top of the ejector pin. During the upward lifting of the mother template, the contact slider will pop out from the ejector pin and fit with the edge of the plastic part to be fixed, thereby making the ejection process more stable and the force more uniform, avoiding stress concentration during the ejection process, and fixing the plastic part after the ejector pin is pushed out to avoid the plastic parts from popping out and falling off to cause damage. At the same time, the surface where the contact slider contacts the plastic part is set to a fitting slope with an angle equal to the demolding slope α, which can help the plastic part to be demolded according to the demolding slope α during the ejection process, reduce the force required for demolding, and thus avoid the occurrence of top whitening or top concave.
[0030] 3. The present invention is provided with a connecting assembly. On the one hand, the plastic parts can be lifted up by lifting the upper fixed plate and the mother template, so that the lifting process is more automated and the demoulding efficiency is improved. The gear transmission makes the entire demoulding process more stable and the speed is controllable. On the other hand, by adjusting the gear ratio between the driven rack and the driving rack, the lifting speed of the lifting assembly is slower than the lifting speed of the upper fixed plate and the mother template, thereby leaving enough space for the plastic parts to be removed, and the lifting speed of the lifting assembly can be slowed down to avoid the whitening phenomenon on the surface of the plastic parts caused by too fast a lifting speed, thereby ensuring the quality of the plastic parts. BRIEF DESCRIPTION OF THE DRAWINGS
[0031] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0032] Figure 1 It is a schematic diagram of the overall structure of the present invention;
[0033] Figure 2 It is a schematic diagram of the structure of the jacking assembly of the present invention;
[0034] Figure 3 is a cross-sectional view of a jacking assembly of the present invention;
[0035] Figure 4 It is a schematic diagram of the top rod structure of the present invention;
[0036] Figure 5 It is a cross-sectional view of the internal structure of the mandrel of the present invention;
[0037] Figure 6 for Figure 5 A magnified view of the structure at center;
[0038] Figure 7 It is a cross-sectional view of the overall structure of the present invention;
[0039] Figure 8 for Figure 7 A magnified view of the structure at B in FIG.
[0040] In the figure: 1, injection hole; 2, male template; 3, female template; 4, cooling assembly; 5, fixing plate; 51, upper fixing plate; 52, lower fixing plate; 6, lifting assembly; 61, guide column; 62, top plate; 63, rising groove; 631, limiting ring; 64, ejector rod; 641, contact end; 6411, contact block; 6412, contact slide; 6413, contact slider; 64131, fitting inclined surface; 6414 , contact spring; 642, sliding end; 643, spring pin; 644, top pressure spring; 65, guide piece; 651, guide groove; 652, pressure piston; 653, cooling groove; 654, drainage groove; 7, connecting assembly; 71, driving rack; 72, driven rack; 721, telescopic guide groove; 722, telescopic rack; 7221, sliding part; 73, gear set; 731, small gear; 732, large gear. DETAILED DESCRIPTION
[0041] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.
[0042] See also Figures 1 to 8 The present invention provides a plastic part injection mold, and the technical solution is as follows:
[0043] As a specific embodiment of the present invention, refer to Figure 1; A plastic part injection mold, comprising an injection hole 1, a male mold plate 2, a female mold plate 3 and a cooling component 4; also comprising a fixing plate 5, a lifting component 6 and a connecting component 7; the fixing plate 5 comprises an upper fixing plate 51 and a lower fixing plate 52; the lifting component 6 is connected to the lower fixing plate 52; the connecting component 7 is connected between the upper fixing plate 51 and the lifting component 6; driven by an external force, a motor or a cylinder with an adjustable lifting speed can be used as a driving member here to lift the upper fixing plate 51 and the female mold plate 3 upward, the upper fixing plate 51 rises to drive the connecting component 7 to rotate, and the rotation of the connecting component 7 drives the lifting component 6 to rise at a speed slower than the upper fixing plate 51, so that a height difference is formed between the lifting height of the lifting component 6 and the lifting height of the upper fixing plate 51 and the female mold plate 3, allowing the plastic part to be taken out, the lifting component 6 rises to press the plastic part, and the lifting component 6 shrinks during the pressing process. When the plastic part is separated from the male mold plate 2, the lifting component 6 recovers and quickly ejects the plastic part.
[0044] As a specific embodiment of the present invention, refer to Figure 2 and Figure 3 The lifting assembly 6 includes a guide column 61, a top plate 62, a rising groove 63, a push rod 64 and a guide member 65; the guide column 61 is connected between the lower fixed plate 52 and the male mold plate 2; the top plate 62 is slidably mounted on the guide column 61; the push rod 64 is connected to the top plate 62; the rising groove 63 is provided inside the male mold plate 2, and a limit ring 631 is provided at the upper end of the rising groove 63; the diameter of the limit ring 631 is smaller than the diameter of the upper end of the push rod 64; the guide member 65 is connected to the cooling assembly 4. The lifting of the top plate 62 can drive the push rod 64 to rise, thereby realizing the lifting movement; the limit ring 631 can ensure that the push rod 64 will not slide downward under the high-pressure working environment, and prevent the melted plastic from entering the rising groove 63; the coolant in the cooling assembly 4 is guided to the push rod 64 through the guide member 65, so that the surface of the push rod 64 is reduced to the optimal demoulding temperature, and the push rod 64 and the plastic parts are prevented from adhering.
[0045] As a specific embodiment of the present invention, refer to Figure 3The guide member 65 includes a guide groove 651, a pressure piston 652, a cooling groove 653 and a drainage groove 654; the guide groove 651 is connected to the cooling assembly 4; the pressure piston 652 is connected to the push rod 64, the pressure piston 652 is an inverted cone structure and the maximum diameter is smaller than the diameter of the guide groove 651. When the lifting movement is not performed, the pressure piston 652 will enter the entrance position of the guide groove 651 to block it, thereby preventing the cooling water from entering the cooling groove 653 when the lifting movement is not performed, and the structure is opened. There is no friction during the closing process, so it has a long service life; the cooling groove 653 is opened on the outer ring of the ejector pin 64, and the cooling groove 653 is a circular ring structure, which is set on the upper outer ring of the ejector pin 64, and the cooling water entering the cooling groove 653 does not directly contact the ejector pin 64, but circulates in the cooling groove 653 for one cycle, and then flows into the drainage groove 654; the drainage groove 654 is connected to the cooling groove 653, and the drainage groove 654 is a channel obliquely connected to the outside world, and the cooling water flowing out of the cooling groove 653 flows out from the drainage groove 654. In the process of lifting, the low-temperature coolant can be directed to the position of the ejector pin 64 to help demolding, and the ejector pin 64 is reduced to a reasonable demolding temperature, thereby reducing the demolding stress and avoiding deformation of the plastic part due to stress concentration; and in the cooling process, the coolant will not reach the position of the ejector pin 64, thereby avoiding deformation of the plastic part due to uneven cooling during the cooling process.
[0046] As a specific embodiment of the present invention, refer to Figure 3 , Figure 4 and Figure 5; The push rod 64 includes a contact end 641, a sliding end 642, a spring pin 643 and a top pressure spring 644; the contact end 641 is connected to the male template 2, and the contact end 641 matches the shape of the bottom surface of the male template 2; the sliding end 642 is connected to the top plate 62; the spring pin 643 is connected to the sliding end 642, and a gap is maintained between the spring pin 643 and the contact end 641; the top pressure spring 644 is sleeved on the spring pin 643 and connected between the sliding end 642 and the contact end 641. By designing the push rod 64 into a segmented structure, when the push rod 64 is pushed upward, the push spring 644 is first compressed during the force process, and then the force is transmitted to the plastic part through the push spring 644. The force is deformed by the spring to form a buffer for the plastic part, thereby avoiding damage to the plastic part. The spring pin 643 can prevent the push spring 644 from radially deforming during the lifting process to cause deviation during the lifting process, thereby ensuring a smooth lifting process. When the push spring 644 is compressed to the point where the spring pin 643 presses against the contact end 641, the lifting force reaches At most, when the plastic part is separated from the male template 2, the top pressure spring 644 returns to its original state and will use elastic force to quickly push the plastic part out and separate it from the male template 2, avoiding the plastic part demolding time being too long, the plastic part cooling and shrinking unevenly and deforming, increasing the clamping force between the male template 2, thereby causing the plastic part surface to wear during the demolding process, and avoiding adhesion between the contact end 641 of the push rod 64 and the plastic part, thereby improving production efficiency; at the same time, the demolding method of slow first and fast later helps to reduce the damage to the plastic part caused by vacuum negative pressure.
[0047] As a specific embodiment of the present invention, refer to Figure 3 , Figure 4 and Figure 5 ; The elastic modulus of the connection position between the top pressure spring 644 and the contact end 641 is greater than the elastic modulus of the connection position between the top pressure spring 644 and the sliding end 642. By changing the elastic modulus, during the lifting process, when the pressure spring 644 is subjected to the upward lifting force of the sliding end 642, the part of the pressure spring 644 with a small elastic modulus will first deform for buffering, so that the lifting force on the plastic part is a gradually increasing process, ensuring that the impact force is reduced when the plastic part is lifted up. For some plastic parts that are easy to deform or have a more complex structure, by slowly increasing the lifting force, they can better adapt to the demolding process, ensure that the lifting force acts evenly on the plastic part, reduce damage caused by material or structural problems, and make the demolding process smoother and more reliable; and because the spring pin 643 and the contact end 641 are not directly connected in the initial state, the large elastic modulus of the connection position between the pressure spring 644 and the contact end 641 helps the pressure spring 644 not to undergo radial deformation, and the part with a small elastic modulus of the pressure spring 644 will not undergo radial deformation under the fixation of the spring pin 643, thereby improving the stability of the lifting process.
[0048] As a specific embodiment of the present invention, refer to Figure 3 , Figure 4 and Figure 5 The contact end 641 includes a contact block 6411, a contact slot 6412, a contact slider 6413 and a contact spring 6414. The contact slot 6412 is provided on the contact block 6411. The contact slider 6413 is installed in the contact slot 6412. The contact spring 6414 is connected between the contact slot 6412 and the contact slider 6413. The notch of the rising groove 63 is provided at the edge of the molding cavity formed by the male mold plate 2 and the female mold plate 3. During the lifting process of the contact end 641, since the female mold plate 3 removes the pressure on the contact slider 6413, the contact slider 6413 extends out above the surface of the male mold plate 2 under the action of the spring and fits with the edge of the plastic part, so that the plastic part is more stable during the demoulding process.
[0049] As a specific embodiment of the present invention, refer to Figure 6 The contact slider 6413 is made of silicone rubber, and the inner surface of the contact slider 6413 is provided with a fitting bevel 64131; the angle of the fitting bevel 64131 is equal to the demoulding slope α. Since the temperature during the injection molding process is generally between 40 and 80 degrees, even if the raw material is polyphenylene sulfide, the mold temperature is below 180 degrees, and silicone rubber can work in an environment of 200 degrees, and after the silicone rubber is fitted with the plastic part, it will not cause wear of the plastic part during the lifting process, and in the process of demoulding and removal, under the fitting effect of the contact slider 6413, it can be ensured that after the demoulding is completed, the plastic part will not be directly ejected, but will reach a position that is convenient for removal, avoiding damage to the plastic part, and the angle of the fitting bevel 64131 is equal to the demoulding slope α, ensuring that the demoulding is carried out at the demoulding slope during the demoulding process, making demoulding easier, avoiding damage to the plastic part, and ensuring the quality of the plastic part.
[0050] As a specific embodiment of the present invention, refer to Figure 7 and Figure 8; The connecting assembly 7 includes a driving rack 71, a driven rack 72 and a gear set 73; the driving rack 71 is connected to the upper fixed plate 51; the driven rack 72 is connected to the top plate 62; the gear set 73 is installed between the driving rack 71 and the driven rack 72. Compared with the traditional injection mold, which requires removing the upper fixed plate 51 and the mother template 3, and then manually lifting the lifting component 6 or pressing the male template 2 downward so that the ejector rod 64 lifts the plastic part from the male template 2 to complete demolding, the connecting component 7 in this scheme can automatically drive the lifting component 6 to move during the upward lifting of the upper fixed plate 51 and the mother template 3, and drive the gear set 73 to rotate by driving the rack 71 to rise, and then drive the driven rack 72 to drive the lifting component 6 to rise through the gear set 73, thereby realizing the lifting function, automating the entire process, improving production efficiency, and ensuring that during the demolding process, the overall movement trajectory of the plastic part is in the vertical direction, and during the removal of the upper fixed plate 51 and the mother template 3, a horizontal force is generated on the plastic part to ensure that the surface of the plastic part is not damaged.
[0051] As a specific embodiment of the present invention, refer to Figure 7 and Figure 8 The gear set 73 includes a pinion 731 and a large gear 732; the pinion 731 is connected to the driving rack 71; the large gear 732 is connected between the driven rack 72 and the pinion 731, and the gear ratio of the large gear 732 to the pinion 731 is greater than 1. By connecting the driving rack 71 to the pinion 731 and the driven rack 72 to the large gear 732, and adjusting the gear ratio of the large gear 732 to the pinion 731, the lifting speed of the upper fixed plate 51 and the lifting assembly 6 can be changed, so that when the upper fixed plate 51 and the mother mold plate 3 rise to a space position where the mold can be detached, the lifting assembly 6 only lifts a short distance, slowing down the lifting speed of the plastic part, avoiding the whitening phenomenon on the surface of the plastic part caused by the excessive lifting speed, and ensuring the quality of the plastic part; the gear ratio of the large gear 732 to the pinion 731 can be adjusted according to the actual products produced, so as to ensure that neither the quality is reduced due to excessive ejection, nor the production efficiency is reduced due to excessive demoulding.
[0052] As a specific embodiment of the present invention, refer to Figure 7 and Figure 8The driven rack 72 includes a telescopic guide groove 721 and a telescopic rack 722; the telescopic guide groove 721 is connected to the lower fixed plate 52; a sliding portion 7221 is provided at the lower portion of the telescopic rack 722; the sliding portion 7221 is slidably installed in the telescopic guide groove 721. When the demoulding work is not performed, the sliding portion 7221 of the telescopic rack 722 can be retracted in the telescopic guide groove 721, thereby reducing the structural space, and under the guiding effect of the telescopic guide groove 721, the lifting component 6 can be guided to ensure the stability of the lifting component 6 during the demoulding process, thereby ensuring that the plastic part will not have a large friction with the side wall of the male mold plate 2 during the demoulding process, and ensuring the quality of the plastic part after demoulding.
[0053] Working principle: lift the upper fixed plate 51 and the female template 3 upward, the upper fixed plate 51 rises and drives the driving rack 71 to rise, the driving rack 71 rises and drives the gear set 73 to rotate, the gear set 73 rotates and drives the driven rack 72 to drive the lifting assembly 6 to rise; the lifting assembly 6 rises and presses the plastic part, and when the plastic part leaves the male template 2, the contact end 641 quickly pushes the plastic part out under the restoring force of the pressing spring 644.
[0054] Specifically, the upper fixing plate 51 and the mother mold plate 3 are lifted upward, and the upper fixing plate 51 rises to drive the driving rack 71 to rise, and the driving rack 71 rises to drive the pinion 731 to rotate, and the pinion 731 drives the large gear 732 to rotate, and the large gear 732 rotates to drive the driven rack 72 to move upward. In this process, the gear ratio of the large gear 732 and the pinion 731 is used to slow down the speed at which the driven rack 72 drives the lifting assembly 6 to rise, thereby slowing down the initial lifting process of the plastic part and making the lifting more stable; during the lifting process, the ejector rod 64 moves upward in the rising groove 63 During the sliding process of the push rod 64, the pressure piston 652 is driven to move upward, so that the cooling water in the cooling component 4 flows through the guide groove 651 into the cooling groove 653, so that the cooling water cools the contact end 641 to avoid adhesion between the contact end 641 and the plastic part during the demoulding process. The cooling water in the cooling groove 653 flows out of the mold through the drainage groove 654; when the female template 3 and the male template 2 are separated, the contact slider 6413 pops up under the elastic force of the contact spring 6414, and makes the fitting bevel 64131 fit with the edge of the plastic part, so as to fit the plastic part The fixing is formed to make the lifting process more stable, and because the angle of the fitting inclined surface 64131 is equal to the demoulding slope α, it helps the plastic part to be demoulded along the demoulding slope, so that the plastic part can be demoulded under a smaller force, thereby reducing the pressure during demoulding and avoiding the generation of whitening; during the lifting process, the top pressure spring 644 is first compressed under the lifting force, so that the plastic part is buffered when the lifting force is applied, and the elastic modulus of the top pressure spring 644 at the connection position with the contact end 641 is greater than the elastic modulus of the top pressure spring 644 at the connection position with the sliding end 642, so that the top pressure spring 644 During the pressing process, the force transmitted to the plastic part gradually increases, so that the plastic part adapts to the demoulding process, thereby helping the plastic part to make the demoulding process smoother and more reliable; when the plastic part is separated from the male template 2, the plastic part can be quickly bounced upwards under the action of the restoring force of the pressing spring 644, so that the demoulding process of the plastic part is from slow to fast, which can further avoid the influence of vacuum negative pressure on the quality of the plastic part, thereby ensuring the demoulding quality of the plastic part. During the pop-up process, the contact slider 6413 will fix the plastic part, avoiding the plastic part from falling out of the mold directly, thus completing the demoulding process.
[0055] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected, and the scope of the present invention to be protected is defined by the attached claims and their equivalents.
Claims
1. A plastic part injection mold, comprising an injection hole (1), a male mold plate (2), a female mold plate (3) and a cooling component (4); characterized in that: The invention also comprises a fixing plate (5), a lifting assembly (6) and a connecting assembly (7); the fixing plate (5) comprises an upper fixing plate (51) and a lower fixing plate (52); the lifting assembly (6) is connected to the lower fixing plate (52); the connecting assembly (7) is connected between the upper fixing plate (51) and the lifting assembly (6); the upper fixing plate (51) and the female template (3) are lifted upward, the upper fixing plate (51) rises to drive the connecting assembly (7) to rotate, the connecting assembly (7) rotates to drive the lifting assembly (6) to rise at a speed slower than that of the upper fixing plate (51), the lifting assembly (6) rises to press the plastic part, during the lifting process of the lifting assembly (6), the cooling water introduced from the outside into the cooling assembly (4) is diverted to the upper outer ring position of the lifting assembly (6), the lifting assembly (6) shrinks during the pressing process, and when the plastic part is separated from the male template (2), the lifting assembly (6) recovers and quickly ejects the plastic part.
2. A plastic part injection mold according to claim 1, characterized in that: The lifting assembly (6) comprises a guide column (61), a top plate (62), a rising groove (63), a push rod (64) and a flow guide (65); the guide column (61) is connected between the lower fixed plate (52) and the male template (2); the top plate (62) is slidably mounted on the guide column (61); the push rod (64) is connected to the top plate (62); the rising groove (63) is provided inside the male template (2), and a limiting ring (631) is provided at the upper end of the rising groove (63); the diameter of the limiting ring (631) is smaller than the diameter of the upper end of the push rod (64); and the flow guide (65) is connected to the cooling assembly (4).
3. A plastic part injection mold according to claim 2, characterized in that: The guide member (65) comprises a guide groove (651), a pressure piston (652), a cooling groove (653) and a drainage groove (654); the guide groove (651) is connected to the cooling assembly (4); the pressure piston (652) is connected to the push rod (64), and the pressure piston (652) is an inverted cone structure; the cooling groove (653) is arranged on the outer ring of the push rod (64); and the drainage groove (654) is connected to the cooling groove (653).
4. The plastic part injection mold according to claim 2, characterized in that: The push rod (64) includes a contact end (641), a sliding end (642), a spring pin (643) and a pressure spring (644); the contact end (641) is connected to the male template (2), and the contact end (641) matches the shape of the bottom surface of the male template (2); the sliding end (642) is connected to the top plate (62); the spring pin (643) is connected to the sliding end (642), and a gap is maintained between the spring pin (643) and the contact end (641); the pressure spring (644) is sleeved on the spring pin (643) and connected between the sliding end (642) and the contact end (641).
5. The plastic part injection mold according to claim 4, characterized in that: The elastic modulus at the connection position between the pressure spring (644) and the contact end (641) is greater than the elastic modulus at the connection position between the pressure spring (644) and the sliding end (642).
6. The plastic part injection mold according to claim 4, characterized in that: The contact end (641) comprises a contact block (6411), a contact groove (6412), a contact slider (6413) and a contact spring (6414); the contact groove (6412) is provided on the contact block (6411); the contact slider (6413) is installed in the contact groove (6412); the contact spring (6414) is connected between the contact groove (6412) and the contact slider (6413); and the notch of the rising groove (63) is arranged at the edge position of the molding cavity formed by the male template (2) and the female template (3).
7. The plastic part injection mold according to claim 6, characterized in that: The contact slider (6413) is made of silicone rubber, and the inner surface of the contact slider (6413) is provided with a fitting slope (64131); the demoulding slope of the male mold plate (2) is α, and the angle of the fitting slope (64131) is equal to the demoulding slope α.
8. The plastic part injection mold according to claim 2, characterized in that: The connecting assembly (7) comprises a driving rack (71), a driven rack (72) and a gear set (73); the driving rack (71) is connected to the upper fixed plate (51); the driven rack (72) is connected to the top plate (62); and the gear set (73) is installed between the driving rack (71) and the driven rack (72).
9. The plastic part injection mold according to claim 8, characterized in that: The gear set (73) comprises a pinion (731) and a large gear (732); the pinion (731) is connected to the driving rack (71); the large gear (732) is connected between the driven rack (72) and the pinion (731), and the gear ratio between the large gear (732) and the pinion (731) is greater than 1.
10. The plastic part injection mold according to claim 9, characterized in that: The driven rack (72) comprises a telescopic guide groove (721) and a telescopic rack (722); the telescopic guide groove (721) is connected to the lower fixed plate (52); a sliding portion (7221) is provided at the lower portion of the telescopic rack (722); the sliding portion (7221) is slidably mounted in the telescopic guide groove (721).