A plastic spiral bevel gear injection mold and a manufacturing method thereof

Abstract

The invention discloses a plastic spiral bevel gear injection mold and a manufacturing method thereof, comprising a top layer upper mold, a middle thin gear main body and a bottom layer lower mold which are stacked in sequence from top to bottom, the middle thin gear main body is provided with an arc groove, the bottom layer lower mold is provided with a first liquid inlet pipe, a first liquid return pipe, and a liquid cooling circulation pipe, the middle part of the middle thin gear main body is hollowed out to provide a first arc groove, the two ends of the first arc groove are respectively connected to the first liquid inlet pipe and the first liquid return pipe to form a first liquid cooling channel; the upper end surface of the bottom layer lower mold is provided with a first annular groove and a second annular groove, the first annular groove and the second annular groove are respectively connected to the liquid cooling circulation pipe; the design can more quickly take away heat from the inside of the mold, especially the gear molding area, to achieve efficient liquid cooling heat dissipation, thereby reducing the shrinkage deformation and dimensional instability of the plastic gear, and improving the overall performance and service life of the final product.

Description

Technical Field

[0001] The invention relates to the technical field of mold gear tools, and in particular to a plastic spiral bevel gear injection mold and a manufacturing method thereof. Background Art

[0002] Plastic gears play an important role in modern industry and are widely used in various mechanical equipment such as automobiles, electronics, and household appliances. With the continuous development of industrial automation and precision manufacturing technology, the requirements for the accuracy and performance of plastic gears are getting higher and higher. In particular, spiral bevel gears have become the first choice for many high-precision transmission systems due to their unique tooth design and transmission efficiency. However, due to the characteristics of plastic materials and the limitations of traditional injection molding processes, how to improve production efficiency and product quality while ensuring high precision has become an urgent problem to be solved in the industry.

[0003] The manufacturing technology of plastic gear molds in the prior art mainly adopts the method of upper and lower molds integrated molding, and the gear products are manufactured by mold combination injection molding. Although this method has a relatively simple process, it has some obvious disadvantages and technical problems in practical applications: the upper and lower molds integrated molding molds in the prior art usually rely on the cooling system of the entire mold to dissipate heat. Since the cooling water channel is designed on the periphery of the mold, it is difficult for the heat to be quickly dissipated from the inside of the mold, especially the part close to the gear molding area, resulting in the mold core temperature being too high; during the injection molding process, the high temperature of the plastic material will cause the temperature inside the mold to rise rapidly, especially in continuous production, the heat will continue to accumulate, causing the mold temperature to continue to rise. This heat accumulation will cause shrinkage deformation and dimensional instability of the plastic gear. Plastic gears are prone to dimensional instability, poor surface quality and tooth surface runout during the molding process, affecting the accuracy and performance of the gear.

[0004] In view of this, it is necessary to improve the plastic gear mold in the prior art to solve the technical problems of insufficient heat dissipation and heat accumulation during the cooling process of the product. Summary of the invention

[0005] The purpose of the present invention is to provide a plastic spiral bevel gear injection mold and a manufacturing method thereof to solve the above technical problems.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] A plastic spiral bevel gear injection mold, comprising a top-layer upper mold, a middle thin-tooth body and a bottom-layer lower mold which are stacked in sequence from top to bottom; wherein the upper end surface of the middle thin-tooth body is provided with an arc groove for injection molding the spiral bevel gear surface;

[0008] The middle thin-tooth body is fixedly mounted on the bottom lower mold, and the bottom lower mold is provided with a first liquid inlet pipe, a first liquid return pipe, and a liquid cooling circulation pipe;

[0009] A first arc groove is hollowed out in the middle of the middle thin-tooth body, the center angle a of the first arc groove is in the range of 180°≤a<360°, and two ends of the first arc groove are respectively connected to the first liquid inlet pipe and the first liquid return pipe to form a first liquid cooling channel;

[0010] The upper end surface of the bottom lower mold is provided with a first annular groove and a second annular groove, the first annular groove is arranged on the inner side of the first arc groove, the second annular groove is arranged on the outer side of the first arc groove, and the first annular groove and the second annular groove are respectively connected to the liquid cooling circulation pipeline.

[0011] Optionally, a molding groove is provided in the middle of the middle thin tooth body, and an injection molding chamber for molding the plastic spiral bevel gear is formed between the lower end surface of the top upper mold, the molding groove and the upper end surface of the bottom lower mold;

[0012] The top layer upper mold is provided with an injection passage, and one end of the injection passage is communicated with the injection cavity.

[0013] Optionally, the bottom lower mold is provided with a mounting hole extending through the bottom lower mold in the vertical direction, a positioning seat is provided in the mounting hole, the upper end surface of the positioning seat is flush with the upper end surface of the bottom lower mold, and an insertion pin portion is provided, and the insertion pin portion is used to form a hollow groove in the plastic spiral bevel gear;

[0014] A positioning pin is arranged in the middle of the positioning seat, and one end of the positioning pin protrudes from the positioning seat and extends upward into the injection molding cavity;

[0015] A positioning sleeve is arranged in the middle of the top-layer upper mold in the vertical direction, and one end of the positioning pin is inserted into the positioning sleeve.

[0016] Optionally, a stepped column is provided at the upper end of the positioning pin, and the stepped column is inserted into the positioning sleeve; wherein the upper end surface of the stepped column is a transition circular curved surface;

[0017] A step surface is formed between the step column and the positioning pin, and the step surface abuts against one end surface of the positioning sleeve.

[0018] Optionally, the upper end surface of the top layer upper mold is provided with a second arc groove, a third annular groove arranged on the inner side of the second arc groove, and a fourth annular groove arranged on the outer side of the second arc groove; wherein the second arc groove extends in the vertical direction toward the interior of the top layer upper mold.

[0019] Optionally, it further comprises an upper mold assembly and a lower mold assembly, wherein the lower mold assembly is provided with a guide column assembly along the vertical direction, and the upper mold assembly is slidably connected to the guide column assembly;

[0020] The upper end surface of the lower mold assembly is provided with a first cavity, the middle thin-tooth body and the bottom lower mold are accommodated in the first cavity, the lower end surface of the upper mold assembly is provided with a second cavity, the top upper mold is accommodated in the second cavity;

[0021] The lower mold assembly includes a base plate, the base plate is provided with a plurality of columns, a lifting plate is slidably connected to the columns, a lifting column is provided at the circumference of the lifting plate, and the lifting column runs through the lower mold assembly; wherein a contraction spring is sleeved on the lifting column, one end of the contraction spring is connected to the lifting plate, and the contraction spring is used to push the lifting column to move upward to lift the upper mold assembly.

[0022] Optionally, the upper mold assembly includes a first plate body and a second plate body stacked in sequence from top to bottom, and the first plate body is provided with an injection port;

[0023] The second plate body is provided with a mounting groove, the inner plate body is installed in the mounting groove, the upper end surface of the inner plate body is provided with an injection flow channel, and the two ends of the injection flow channel are respectively connected with the injection port and the injection passage;

[0024] Wherein, the injection molding flow channel is provided with a plurality of flow paths, and each flow path is respectively connected with a corresponding injection molding passage.

[0025] The present invention also provides a method for manufacturing a plastic spiral bevel gear, which is implemented by using the plastic spiral bevel gear injection mold as described above, and the manufacturing method comprises:

[0026] Step S1: stacking and assembling the top upper mold, the middle thin-tooth body and the bottom lower mold in sequence, so that the arc groove of the middle thin-tooth body is sealed and connected with the liquid cooling circulation pipeline of the bottom lower mold;

[0027] Step S2: Add the plastic raw material into the injection molding machine and set the initial parameters of the injection molding machine;

[0028] Step S3: starting the injection molding machine, injecting the heated and molten plastic raw material into the arc groove of the middle thin tooth body through the injection molding passage, and using the segmented injection molding technology to injection mold the plastic spiral bevel gear;

[0029] Step S4: After the injection molding is completed, the intelligent cooling system is started to control the flow and temperature of each cooling channel according to the cooling requirements of different parts of the plastic spiral bevel gear;

[0030] Step S5, after the plastic spiral bevel gear is cooled and solidified, the automatic demoulding system is started to take the molded plastic spiral bevel gear product out of the mold, and the appearance and size of the plastic spiral bevel gear product are inspected in real time through the online quality inspection system.

[0031] Optionally, the step S3 specifically includes:

[0032] Step S31: pre-filling, injecting heated and molten plastic raw materials into the arc groove of the middle thin tooth body at a low speed and low pressure;

[0033] Step S32: After the pre-filling is completed, the injection speed and pressure are gradually increased to quickly inject the plastic material into the remaining part of the arc groove;

[0034] Step S33: After the plastic material completely fills the arc groove, the pressure holding stage is entered; at this time, the preset injection pressure is maintained to fully compact the plastic material in the mold;

[0035] Step S34: during the pressure holding stage, starting the liquid cooling circulation pipeline and the first liquid cooling channel, and controlling the mold temperature through the liquid cooling circulation system;

[0036] Step S35: After the injection molding is completed, cooling is continued through the liquid cooling circulation pipeline and the first liquid cooling channel to make the plastic spiral bevel gear evenly cooled and solidified.

[0037] Compared with the prior art, the present invention has the following beneficial effects: the injection mold comprises a top upper mold, a middle thin-tooth body and a bottom lower mold; the middle thin-tooth body is used for injection molding the spiral bevel gear surface; the middle of the middle thin-tooth body is hollowed out to provide a first circular arc groove, and a first liquid cooling channel is formed; the upper end surface of the bottom lower mold is provided with alternating first circular annular grooves and second circular annular grooves, forming another liquid cooling cycle; during the operation of the mold, the coolant flowing in the first circular arc groove penetrates into the middle thin-tooth body for circulation, directly cooling the plastic spiral bevel gear, and after absorbing the heat in the mold, passes through the first liquid return pipe At the same time, the liquid cooling circulation pipeline further cools the middle thin gear body through the first annular groove and the second annular groove to ensure uniform temperature distribution; this mold realizes efficient liquid cooling heat dissipation through the independently set middle thin gear body and the internal spiral water cooling pipeline system; compared with the traditional upper and lower mold one-piece molding method, this design can more quickly take away the heat from the inside of the mold, especially the gear molding area, to avoid heat accumulation; and multi-stage annular grooves are set to further enhance the cooling effect, thereby reducing the shrinkage deformation and dimensional instability of the plastic gear, and improving the overall performance and service life of the final product. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0039] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with this technology. They are not used to limit the conditions under which the present invention can be implemented, and therefore have no substantive technical significance. Any structural modification, change in proportion or adjustment of size, without affecting the effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical contents disclosed by the present invention.

[0040] Figure 1 This is a schematic diagram of the inner mold body structure of the plastic spiral bevel gear injection mold of the first embodiment;

[0041] Figure 2 It is a schematic cross-sectional structure diagram of the inner mold body of the plastic spiral bevel gear injection mold of the first embodiment of the present invention from a first viewing angle;

[0042] Figure 3 It is a schematic cross-sectional structure diagram of the inner mold body of the plastic spiral bevel gear injection mold of the first embodiment from a second viewing angle;

[0043] Figure 4 This is a schematic structural diagram of a positioning seat of an inner mold body of a plastic spiral bevel gear injection mold according to the first embodiment of the present invention;

[0044] Figure 5 This is a schematic structural diagram of the middle thin tooth body of the inner mold body of the plastic spiral bevel gear injection mold of the first embodiment;

[0045] Figure 6 It is a schematic diagram of the cooling channel layout of the inner mold body of the plastic spiral bevel gear injection mold of the first embodiment of the present invention;

[0046] Figure 7 This is a schematic diagram of the overall structure of the plastic spiral bevel gear injection mold of the first embodiment;

[0047] Figure 8 This is a schematic structural diagram of the lower mold assembly of the plastic spiral bevel gear injection mold of the first embodiment;

[0048] Fig. 9 Schematic diagram of the structure of the upper mold assembly of the plastic spiral bevel gear injection mold of the first embodiment.

[0049] Illustrations: top upper mold 100, middle thin-tooth body 200, bottom lower mold 300, arc groove 201, first liquid inlet pipe 310, first liquid return pipe 320, liquid cooling circulation pipe 330, first arc groove 202, first annular groove 301, second annular groove 302, injection molding chamber 400, injection molding passage 110, mounting hole 340, positioning seat 350, insertion pin portion 360, positioning pin 370, positioning sleeve 12 0, stepped column 371, transition circular curved surface 372, stepped surface 373, second arc groove 101, third annular groove 102, fourth annular groove 103, upper mold assembly 500, lower mold assembly 600, bottom plate 610, column 620, lift plate 630, lift column 640, contraction spring 650, first plate body 510, second plate body 520, injection port 530, mounting groove 521, inner plate body 540, injection channel 541. DETAILED DESCRIPTION

[0050] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] In the description of the present invention, it should be understood that the terms "upper", "lower", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. It should be noted that when a component is considered to be "connected" to another component, it may be directly connected to the other component or there may be a centrally arranged component at the same time.

[0052] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0053] Embodiment 1:

[0054] An embodiment of the present invention provides a plastic spiral bevel gear injection mold, which mainly includes an inner mold body, wherein the inner mold body includes a top layer upper mold 100, a middle thin tooth body 200 and a bottom layer lower mold 300 stacked in sequence from top to bottom; wherein, an arc groove 201 for injection molding a spiral bevel gear surface is opened on the upper end face of the middle thin tooth body 200, and a plurality of arc grooves 201 are designed, and the plurality of arc grooves 201 are evenly arranged along the circumferential direction of the end face of the middle thin tooth body 200; the design feature of the plastic spiral bevel gear injection mold lies in its layered structure, wherein the independently designed middle thin tooth body 200 is the main structure for molding the plastic spiral bevel gear.

[0055] The middle thin-tooth body 200 is fixedly mounted on the bottom lower mold 300, and the bottom lower mold 300 is provided with a first liquid inlet pipe 310 and a first liquid return pipe 320, as well as a liquid cooling circulation pipe 330; the middle thin-tooth body 200 is firmly fixed on the bottom lower mold 300 to ensure the overall structural stability of the mold. The bottom lower mold 300 is provided with a first liquid inlet pipe 310 and a first liquid return pipe 320, which are used for the flow of cooling liquid. In addition, a liquid cooling circulation pipe 330 is also provided, and these pipes together constitute the cooling system of the mold to ensure that heat can be effectively dissipated during the injection molding process to prevent the mold from overheating.

[0056] The middle part of the middle thin-tooth body 200 is hollowed out to set a first circular arc groove 202, and the range of the central angle a of the first circular arc groove 202 is 180°≤a<360°. The two ends of the first circular arc groove 202 are respectively connected to the first liquid inlet pipe 310 and the first liquid return pipe 320 to form a first liquid cooling channel; the central angle a of the first circular arc groove 202 is set to 180°~360°, which can fully ensure the cooling and heat dissipation effect of the first circular arc groove 202, and at the same time needs to be less than one circle (360°), thereby forming a liquid cooling circulation channel.

[0057] The upper end surface of the bottom lower mold 300 is provided with a first annular groove 301 and a second annular groove 302. The first annular groove 301 is arranged on the inner side of the first arc groove 202, and the second annular groove 302 is arranged on the outer side of the first arc groove 202. The first annular groove 301 and the second annular groove 302 are respectively connected to the liquid cooling circulation pipeline 330.

[0058] Among them, combined Figure 6 As shown, it is a schematic diagram of the cooling channel layout of the inner mold body. The figure indicates the position distribution relationship between the first arc groove 202, the first annular groove 301 and the second annular groove 302. Please note that this does not mean that these three are located on the same component.

[0059] It should be noted that the two ends of the first arc groove 202 are respectively connected to the first liquid inlet pipe 310 and the first liquid return pipe 320 to form a first liquid cooling channel. The first liquid cooling channel goes deep into the interior of the middle thin-tooth body 200. Since it is close to the plastic spiral bevel gear product, it can directly cool and dissipate the product in the middle thin-tooth body 200 as a primary heat dissipation. In addition, the first annular groove 301 and the second annular groove 302 are arranged in contact with the bottom lower mold 300 to form another liquid cooling cycle, which plays a role in cooling the middle thin-tooth body 200 and the contact part between the bottom lower mold 300 and the product as a secondary heat dissipation. By independently setting the middle thin-tooth body 200, the upper and lower molds can be broken up and reconstructed, thereby establishing a multi-stage liquid cooling cycle heat dissipation, which plays a better heat dissipation role and avoids heat accumulation.

[0060] The working principle of the present invention is as follows: the injection mold comprises three parts, namely, a top upper mold 100, a middle thin-tooth body 200 and a bottom lower mold 300. The middle thin-tooth body 200 is used for injection molding the spiral bevel gear surface. The middle of the middle thin-tooth body 200 is hollowed out to set a first circular arc groove 202, and a first liquid cooling channel is formed. The upper end surface of the bottom lower mold 300 is provided with alternating first circular grooves 301 and second circular grooves 302, forming another liquid cooling cycle. During the operation of the mold, the coolant flowing in the first circular arc groove 202 penetrates into the middle thin-tooth body 200 for circulation, directly cooling the plastic spiral bevel gear, and after absorbing the heat in the mold, passes through the first circulation. The liquid is discharged through the liquid pipe 320. At the same time, the liquid cooling circulation pipe 330 further cools the middle thin-tooth body 200 through the first annular groove 301 and the second annular groove 302 to ensure uniform temperature distribution. The mold achieves efficient liquid cooling through the independently arranged middle thin-tooth body 200 and the internal spiral water cooling pipe system. Compared with the traditional upper and lower mold one-piece molding method, the present design can more quickly take away the heat from the inside of the mold, especially the gear molding area, to avoid heat accumulation. Multi-stage annular grooves are provided to further enhance the cooling effect, thereby reducing the shrinkage deformation and dimensional instability of the plastic gear and improving the overall performance and service life of the final product.

[0061] In this embodiment, a molding groove is opened in the middle of the middle thin-tooth body 200, and an injection molding chamber 400 for molding plastic spiral bevel gears is formed between the lower end surface of the top upper mold 100, the molding groove and the upper end surface of the bottom lower mold 300; the top upper mold 100 is provided with an injection molding passage 110, and one end of the injection molding passage 110 is connected to the injection molding chamber 400.

[0062] It should be noted that a molding groove is provided in the middle of the middle thin tooth body 200 of the injection mold, and the molding groove, the lower end surface of the top upper mold 100 and the upper end surface of the bottom lower mold 300 together form a complete injection molding chamber 400 for molding plastic spiral bevel gears. Extending from one end of the top upper mold 100 to the injection molding chamber 400, it ensures that the molten plastic raw material can be smoothly injected into the injection molding chamber 400, thereby realizing the molding of the plastic spiral bevel gears.

[0063] In the present embodiment, it is further explained that a mounting hole 340 is provided through the bottom lower mold 300 along the vertical direction, a positioning seat 350 is arranged in the mounting hole 340, the upper end surface of the positioning seat 350 is flush with the upper end surface of the bottom lower mold 300, and an insertion pin portion 360 is provided, and the insertion pin portion 360 is used to form a hollow groove in the plastic spiral bevel gear; a positioning pin 370 is provided in the middle of the positioning seat 350, one end of the positioning pin 370 protrudes from the positioning seat 350 and extends upward into the injection molding chamber 400; a positioning sleeve 120 is provided in the middle of the top upper mold 100 along the vertical direction, and one end of the positioning pin 370 is inserted into the positioning sleeve 120.

[0064] The purpose of this design is to make the molding structure of the entire plastic spiral bevel gear assembled in blocks, which is convenient for reducing heat accumulation. Corresponding cooling structures can be set up separately to improve the cooling effect of the product. At the same time, different mold components are processed and formed separately, which helps to improve the surface accuracy and manufacturing accuracy of the mold.

[0065] As a preferred solution of this embodiment, a step column 371 is provided at the upper end of the positioning pin 370, and the step column 371 is inserted into the positioning sleeve 120; wherein, the upper end surface of the step column 371 is a transition circular curved surface 372; a step surface 373 is formed between the step column 371 and the positioning pin 370, and the step surface 373 abuts against one end surface of the positioning sleeve 120.

[0066] It should be noted that the upper end of the positioning pin 370 is provided with a stepped column 371, and the stepped column 371 is inserted into the positioning sleeve 120. The upper end surface of the stepped column 371 is a transition circular curved surface 372 to ensure a smooth transition during insertion. A stepped surface 373 is formed between the stepped column 371 and the positioning pin 370, and the stepped surface 373 abuts against one end surface of the positioning sleeve 120. Through this design, the tight fit between the positioning pin 370 and the positioning sleeve 120 can be better ensured, the positioning accuracy of the upper and lower molds can be improved, and the molding quality and accuracy of the plastic spiral bevel gear can be further improved.

[0067] In this embodiment, the upper end surface of the top layer upper mold 100 is provided with a second arc groove 101, a third annular groove 102 arranged on the inner side of the second arc groove 101, and a fourth annular groove 103 arranged on the outer side of the second arc groove 101; wherein, the second arc groove 101 extends inwardly of the top layer upper mold 100 in a vertical direction.

[0068] It should be noted that, in this embodiment, a second circular arc groove 101 is designed on the upper end surface of the top upper mold 100, and a third annular groove 102 and a fourth circular annular groove 103 are respectively arranged on the inner and outer sides thereof. The design of these grooves helps to further optimize the cooling effect of the mold. The second circular arc groove 101 extends vertically toward the inside of the top upper mold 100, increasing the flow path of the coolant, ensuring that the coolant can fully contact the inside of the mold and improving the heat dissipation efficiency. The third annular groove 102 and the fourth circular annular groove 103 are respectively located on the inner and outer sides of the second circular arc groove 101, forming a multi-level cooling structure, making the temperature distribution of the mold more uniform, avoiding local overheating, and improving the molding quality and precision of the plastic spiral bevel gear.

[0069] It is further explained that the injection mold also includes an upper mold assembly 500 and a lower mold assembly 600. The lower mold assembly 600 is provided with a guide column assembly along the vertical direction, and the upper mold assembly 500 is slidably connected to the guide column assembly; the upper end surface of the lower mold assembly 600 is provided with a first cavity, and the middle thin-tooth body 200 and the bottom lower mold 300 are accommodated in the first cavity; the lower end surface of the upper mold assembly 500 is provided with a second cavity, and the top upper mold 100 is accommodated in the second cavity.

[0070] The lower mold assembly 600 includes a base plate 610, and the base plate 610 is provided with a plurality of columns 620. A lifting plate 630 is slidably connected to the column 620. A lifting column 640 is provided at the circumference of the lifting plate 630. The lifting column 640 runs through the lower mold assembly 600. A contraction spring 650 is sleeved on the lifting column 640, and one end of the contraction spring 650 is connected to the lifting plate 630. The contraction spring 650 is used to push the lifting column 640 to move upward to lift the upper mold assembly 500.

[0071] It should be noted that the upper end surface of the lower mold assembly 600 is provided with a first cavity for accommodating the middle thin-tooth body 200 and the bottom lower mold 300, and the lower end surface of the upper mold assembly 500 is provided with a second cavity for accommodating the top upper mold 100. This cavity design can accommodate multiple sets of mold monomer structures (a combination of the top upper mold 100, the middle thin-tooth body 200 and the bottom lower mold 300), making the mold structure more compact and easy to install and disassemble.

[0072] In addition, the lower mold assembly 600 includes a bottom plate 610 and a lifting plate 630 slidably connected to the column 620, and a lifting column 640 is provided at the circumference of the lifting plate 630. The lifting column 640 runs through the lower mold assembly 600 and is covered with a contraction spring 650. One end of the contraction spring 650 is connected to the lifting plate 630, and is used to push the lifting column 640 to move upward, thereby lifting the upper mold assembly 500. The design of this lifting device makes the demoulding process smoother and more efficient, avoids product damage caused by excessive demoulding force, and improves production efficiency and product quality. In particular, through the driving effect of the contraction spring 650, automated lifting and demoulding operations can be achieved, improving the automation level and operational safety of the production line.

[0073] In this embodiment, the upper mold assembly 500 includes a first plate body 510 and a second plate body 520 which are stacked in sequence from top to bottom, and the first plate body 510 is provided with an injection port 530; the second plate body 520 is provided with a mounting groove 521, and an inner plate body 540 is installed in the mounting groove 521, and an injection channel 541 is provided on the upper end surface of the inner plate body 540, and both ends of the injection channel 541 are respectively connected to the injection port 530; wherein, the injection channel 541 is provided with a plurality of flow paths, and each flow path is respectively connected to the corresponding ones.

[0074] It should be noted that the two ends of the injection flow channel 541 are respectively connected to the injection port 530 and the injection port 530 to ensure that the plastic raw material can flow smoothly into the injection chamber 400. In order to improve the injection efficiency and molding quality, the injection flow channel 541 is designed with multiple flow paths, each of which is respectively connected to the corresponding injection passage 110. This multi-flow path design can evenly distribute the plastic raw material, avoid the problem of uneven flow caused by a single flow channel, ensure that each can be fully filled, and finally achieve high-quality molding of the plastic spiral bevel gear.

[0075] Embodiment 2:

[0076] The present invention also provides a method for manufacturing a plastic spiral bevel gear, which is implemented by using the plastic spiral bevel gear injection mold as in the first embodiment. The manufacturing method comprises:

[0077] Step S1: stacking and assembling the top upper mold 100, the middle thin-tooth body 200 and the bottom lower mold 300 in sequence, so that the arc groove 201 of the middle thin-tooth body 200 is sealed and connected with the liquid cooling circulation pipe 330 of the bottom lower mold 300;

[0078] Step S2: Add the plastic raw material into the injection molding machine and set the initial parameters of the injection molding machine; the initial parameters include injection temperature, pressure and time. Start the intelligent monitoring system to monitor various parameters in the injection molding process, such as temperature, pressure and flow rate, in real time, and dynamically adjust the injection molding parameters according to the monitoring data to ensure the stability and consistency of the injection molding process.

[0079] Step S3: Start the injection molding machine, inject the heated molten plastic raw material into the arc groove 201 of the middle thin tooth body 200, and use the segmented injection molding technology to injection mold the plastic spiral bevel gear; wherein, the segmented injection molding technology is used to divide the injection molding process into multiple stages, and different injection molding parameters are adjusted in each stage to optimize the flow and filling effect of the plastic. During the injection molding process, the coolant enters the first arc groove 202 through the first liquid inlet pipe 310, circulates along the first liquid cooling channel, absorbs the heat in the mold, and is discharged through the first liquid return pipe 320. At the same time, the liquid cooling circulation pipe 330 further cools the mold through the first annular groove 301 and the second annular groove 302 to ensure uniform temperature distribution.

[0080] Step S4: After the injection molding is completed, the intelligent cooling system is started to control the flow and temperature of each cooling channel according to the cooling requirements of different parts of the plastic spiral bevel gear, ensuring that the plastic spiral bevel gear is evenly cooled and solidified in the mold. The heat of the plastic gear product is quickly removed through the multi-stage liquid cooling circulation system to prevent heat accumulation and reduce shrinkage and deformation of the product. Real-time monitoring and adjustment of cooling parameters to ensure the best cooling effect;

[0081] Step S5, after the plastic spiral bevel gear is cooled and solidified, the automatic demoulding system is started to take the molded plastic spiral bevel gear product out of the mold, and the appearance and size of the plastic spiral bevel gear product are inspected in real time through the online quality inspection system to ensure that it meets the design requirements. If necessary, the product is automatically post-processed, such as deburring and surface treatment, to ensure product quality. The inspection data is recorded in real time to form a product quality traceability system.

[0082] In this embodiment, it is specifically described that step S3 specifically includes:

[0083] Step S31: Pre-filling, injecting heated molten plastic raw materials into the arc groove 201 of the middle thin tooth body 200 at a low speed and low pressure; ensuring that the plastic raw materials are evenly distributed in the arc groove 201 to avoid the generation of bubbles and gaps. The main purpose of this stage is to pre-fill the plastic raw materials to provide a uniform foundation for subsequent high-pressure injection molding.

[0084] Step S32: After the pre-filling is completed, the injection speed and pressure are gradually increased to quickly inject the plastic material into the remaining part of the arc groove 201; the purpose of this stage is to quickly fill the mold to ensure that the plastic material completely covers the toothed groove to avoid incomplete filling due to too fast cooling.

[0085] Step S33: After the plastic material completely fills the arc groove 201, it enters the pressure holding stage; at this time, the preset injection pressure is maintained to fully compact the plastic material in the mold; the volume change caused by cooling shrinkage is eliminated to ensure the surface quality and dimensional accuracy of the gear.

[0086] Step S34: During the pressure holding stage, the liquid cooling circulation pipeline 330 and the first liquid cooling channel are started, and the mold temperature is controlled by the liquid cooling circulation system to prevent the mold from overheating and ensure that the plastic material is evenly cooled in the mold. The cooling at this stage is mainly to maintain the working temperature of the mold and prevent the plastic material from cooling and solidifying prematurely.

[0087] Step S35: After the injection molding is completed, the liquid cooling circulation pipeline 330 and the first liquid cooling channel are continued to be cooled so that the plastic spiral bevel gear is evenly cooled and solidified. At this time, the flow rate and temperature of each cooling channel are controlled respectively to ensure that the plastic spiral bevel gear maintains a uniform temperature distribution during the cooling process and reduces shrinkage deformation. After the cooling and solidification is completed, the pre-mold release system is started to loosen the mold slightly to ensure that the plastic spiral bevel gear is separated from the mold surface to avoid product damage caused by excessive demolding force.

[0088] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for manufacturing a plastic spiral bevel gear, characterized in that: The plastic spiral bevel gear injection mold is used for the production, and the plastic spiral bevel gear injection mold comprises a top-layer upper mold, a middle thin-tooth body and a bottom-layer lower mold which are stacked in sequence from top to bottom; wherein the upper end surface of the middle thin-tooth body is provided with an arc groove for injection molding the spiral bevel gear surface; The middle thin-tooth body is fixedly mounted on the bottom lower mold, and the bottom lower mold is provided with a first liquid inlet pipe, a first liquid return pipe, and a liquid cooling circulation pipe; A first arc groove is hollowed out in the middle of the middle thin-tooth body, the center angle a of the first arc groove is in the range of 180°≤a<360°, and two ends of the first arc groove are respectively connected to the first liquid inlet pipe and the first liquid return pipe to form a first liquid cooling channel; The upper end surface of the bottom lower mold is provided with a first annular groove and a second annular groove, wherein the first annular groove is arranged on the inner side of the first arc groove, and the second annular groove is arranged on the outer side of the first arc groove, and the first annular groove and the second annular groove are respectively connected to the liquid cooling circulation pipeline; A molding groove is provided in the middle of the middle thin tooth body, and an injection molding chamber for molding the plastic spiral bevel gear is formed between the lower end surface of the top upper mold, the molding groove and the upper end surface of the bottom lower mold; The top mold is provided with an injection passage, one end of which is connected to the injection chamber; The bottom lower mold is provided with a mounting hole extending through the bottom lower mold in the vertical direction, a positioning seat is provided in the mounting hole, the upper end surface of the positioning seat is flush with the upper end surface of the bottom lower mold, and an insertion pin portion is provided, and the insertion pin portion is used to form a hollow groove in the plastic spiral bevel gear; A positioning pin is arranged in the middle of the positioning seat, and one end of the positioning pin protrudes from the positioning seat and extends upward into the injection molding cavity; A positioning sleeve is provided in the middle of the top upper mold in the vertical direction, and one end of the positioning pin is inserted into the positioning sleeve; A stepped column is provided at the upper end of the positioning pin, and the stepped column is inserted into the positioning sleeve; wherein the upper end surface of the stepped column is a transition circular curved surface; A step surface is formed between the step column and the positioning pin, and the step surface abuts against one end surface of the positioning sleeve; The upper end surface of the top upper die is provided with a second arc groove, a third annular groove arranged inside the second arc groove, and a fourth annular groove arranged outside the second arc groove; wherein the second arc groove extends vertically toward the inside of the top upper die; It also includes an upper mold assembly and a lower mold assembly, wherein the lower mold assembly is provided with a guide column assembly along the vertical direction, and the upper mold assembly is slidably connected to the guide column assembly; The upper end surface of the lower mold assembly is provided with a first cavity, the middle thin-tooth body and the bottom lower mold are accommodated in the first cavity, the lower end surface of the upper mold assembly is provided with a second cavity, the top upper mold is accommodated in the second cavity; The lower mold assembly comprises a bottom plate, the bottom plate is provided with a plurality of columns, a lifting plate is slidably connected to the columns, a lifting column is provided at the circumference of the lifting plate, and the lifting column runs through the lower mold assembly; wherein a contraction spring is sleeved on the lifting column, one end of the contraction spring is connected to the lifting plate, and the contraction spring is used to push the lifting column to move upward to lift the upper mold assembly; The manufacturing method comprises: Step S1: stacking and assembling the top upper mold, the middle thin-tooth body and the bottom lower mold in sequence, so that the arc groove of the middle thin-tooth body is sealed and connected with the liquid cooling circulation pipeline of the bottom lower mold; Step S2: Add the plastic raw material into the injection molding machine and set the initial parameters of the injection molding machine; Step S3: starting the injection molding machine, injecting the heated and molten plastic raw material into the arc groove of the middle thin tooth body through the injection molding passage, and using the segmented injection molding technology to injection mold the plastic spiral bevel gear; Step S4: After the injection molding is completed, the intelligent cooling system is started to control the flow and temperature of each cooling channel according to the cooling requirements of different parts of the plastic spiral bevel gear; Step S5, after the plastic spiral bevel gear is cooled and solidified, the automatic demoulding system is started to take the molded plastic spiral bevel gear product out of the mold, and the appearance and size of the plastic spiral bevel gear product are inspected in real time through the online quality inspection system; Wherein, the step S3 specifically includes: Step S31: pre-filling, injecting heated and molten plastic raw materials into the arc groove of the middle thin tooth body at a low speed and low pressure; Step S32: After the pre-filling is completed, the injection speed and pressure are gradually increased to quickly inject the plastic material into the remaining part of the arc groove; Step S33: After the plastic material completely fills the arc groove, the pressure holding stage is entered; at this time, the preset injection pressure is maintained to fully compact the plastic material in the mold; Step S34: during the pressure holding stage, starting the liquid cooling circulation pipeline and the first liquid cooling channel, and controlling the mold temperature through the liquid cooling circulation system; Step S35: After the injection molding is completed, cooling is continued through the liquid cooling circulation pipeline and the first liquid cooling channel to make the plastic spiral bevel gear evenly cooled and solidified.

2. The method for manufacturing a plastic spiral bevel gear according to claim 1, characterized in that: The upper mold assembly comprises a first plate body and a second plate body stacked in sequence from top to bottom, wherein the first plate body is provided with an injection port; The second plate body is provided with a mounting groove, the inner plate body is installed in the mounting groove, the upper end surface of the inner plate body is provided with an injection flow channel, and the two ends of the injection flow channel are respectively connected with the injection port and the injection passage; Wherein, the injection molding flow channel is provided with a plurality of flow paths, and each flow path is respectively connected with a corresponding injection molding passage.

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