Method for machining exhaust insert and use thereof

Abstract

The application provides a processing method of an exhaust insert, and specifically comprises the following steps: S1, cutting and rough machining to obtain a required workpiece shape; S2, using a hole opening device to process a diameter D exhaust hole on the workpiece; S3, adopting a forging forming process to forge the workpiece, so that the exhaust hole is extruded and reduced in the same direction to form a micro slit; S4, measuring the micro slit length a and calculating the micro slit width b, until the target micro slit width range is reached, if the calculated micro slit width b cannot reach the target micro slit width range, repeating step S3; S5, finishing, to obtain the exhaust insert with the micro slit. The application also provides the exhaust insert with the micro slit processed by the processing method of the exhaust insert. The application overcomes the deficiency that the existing processing method of the exhaust insert cannot well process extremely small micro slits, and can process the exhaust insert with extremely small pores and excellent exhaust effect. The processed exhaust insert can well meet the exhaust demand and does not affect the appearance quality of the injection molding or die casting product.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of exhaust inserts, and more particularly to a processing method of an exhaust insert and application thereof. BACKGROUND

[0002] Both die casting molds and injection molds have common process features, that is, high-temperature molten material is filled into a mold cavity, and then solidified through a cooling process. In a naturally vented mold, such as an engine cylinder die casting mold and an injection mold for an airbag, the design of an exhaust system is a key factor in product forming. The main means include: through an exhaust structure or an exhaust groove opened on a mold parting surface, air in the mold cavity and air generated by molten liquid are discharged from the mold to avoid trapped air, resulting in defects such as air marks, air bubbles, and shrinkage holes. These defects can cause problems such as insufficient strength of structural injection molded parts, appearance bulging, poor adhesion of appearance painting, and leakage of oil and water channels in engine cylinders.

[0003] The exhaust insert can be embedded in the mold body to enhance the exhaust performance of the mold. Through the exhaust effect of the venting insert, not only the production efficiency can be improved, but also the formation of trapped air during the injection molding and die casting process can be avoided, which can cause defects such as air marks, air bubbles, and shrinkage holes in the product. In the injection molding and die casting process, the hardness, strength, and pore size of the exhaust insert can affect the use effect of the exhaust insert and the appearance quality of the product. The physical properties of the exhaust insert depend on the processing method of the exhaust insert. For some injection molded or die cast parts with high quality and appearance requirements, the exhaust pore size of the exhaust insert can also affect the appearance quality of the product. If the exhaust pore size is too small, it can easily block the exhaust and affect the exhaust. If the exhaust pore size is too large, the injection or die casting material can benefit from the exhaust pore, which can easily form a protrusion on the appearance of the product, affecting the appearance quality of the product. At present, the exhaust pore size of the exhaust insert is realized by drilling. Based on the size limitation of the drilling tool, the exhaust pore size of the exhaust insert cannot be too small. Therefore, it is necessary to develop a processing method of an exhaust insert to form a venting micro-slit, that is, to have an exhaust effect without affecting the quality of the product produced. SUMMARY

[0004] The present application aims to overcome the shortcomings of the prior art that the processing method of the exhaust insert cannot process extremely small micro-slit, and provides a processing method of an exhaust insert. The method can process an exhaust insert with extremely small pores and excellent exhaust effect. The processed exhaust insert can well meet the exhaust demand and does not affect the appearance quality of the injection molded or die cast product.

[0005] To solve the above technical problems, the technical solution adopted by the present application is as follows:

[0006] A processing method of an exhaust insert, specifically comprising the following steps:

[0007] S1: cutting and rough machining to obtain the required workpiece shape;

[0008] S2: using a hole opening device to process an exhaust hole with a diameter D on the workpiece;

[0009] S3: adopting a forging forming process to forge the workpiece, so that the exhaust hole is extruded and narrowed in the same direction to form a micro slit;

[0010] S4: measuring the length a of the micro slit and calculating the width b of the micro slit, until the target micro slit width range is reached, if the calculated micro slit width b does not reach the target micro slit width range, repeat step S3;

[0011] S5: according to the requirements of the part drawing, the workpiece is finished to obtain an exhaust insert with a micro slit.

[0012] The present application adopts a forging forming process to compress and lengthen the exhaust hole opening to form a slit-shaped micro slit. According to the fact that the circumference of the exhaust hole port does not change before and after forging, the length of the forged exhaust micro slit can be measured to determine the size of the micro slit width. After the deformation of the exhaust hole, the air flow is not affected, but the air passage is changed into a long and narrow slit. The slit width can be controlled below the overflow value of various die casting or injection molding materials. The micro slit width can be controlled in a very small range. The micro slit can release the residual pressure in the mold cavity and prevent the overflow defect of the injection or die casting product surface. The processing method of the present application is simple, easy to operate and low in cost, and can be widely applied to the production and processing of various exhaust inserts in the die casting and injection molding industries.

[0013] Further, the target micro slit width range is 0.005mm~0.05mm. It should be noted that the commonly used injection or die casting materials include but are not limited to ABS, PMMA, hard PVC, soft PVC, PE / HDPE / LDPE, PPO / PPE, PP, PP+GF / PP+TD, TPE / TPV / TPU, PA / PA6 / PA66, (PA / PA6 / PA66)+GF, POM / POM+GF, AL (aluminum alloy) and the like. The overflow value of the commonly used materials is between 0.01mm and 0.05mm. Therefore, for exhaust inserts used in different material injection or die casting, the target micro slit width can be reasonably adjusted to be smaller than the overflow value of the material, so as to ensure good exhaust performance and not affect the appearance quality of the product.

[0014] Further, after step S4 and before step S5, there is also a step S41: micro slit detection, detecting the actual width of the micro slit of the exhaust insert with a micro slit and the air flow. If the actual width of the micro slit does not reach the target micro slit width range, repeat steps S3 and S4. If the micro slit cannot ventilate, repeat steps S2 to S4.

[0015] Further, the actual width of the micro gap is detected by microscopy, and the ventilation condition of the micro gap is detected by visual inspection or air suction / drawing detection.

[0016] It should be noted that the micro gap width b is calculated during forging to meet the requirement of quickly calibrating the current width range, so as to facilitate the quick forging operation, and after the target micro gap width is reached, the micro gap is detected by a measuring tool, which is an actual detection of the target micro gap width, and can accurately measure the specific width and eliminate possible errors in the calculation.

[0017] Further, the calculation relationship of the micro gap width b in step S4 is: a = πD / 2-b; wherein D is the diameter of the exhaust hole, a is the length of the micro gap, and b is the width of the micro gap.

[0018] It should be noted that the length of the exhaust micro gap after forging can be measured to quickly judge the size of the micro gap according to the unchanged circumference of the exhaust hole port before and after forging, and the quick judgment of the size of the micro gap can meet the requirement of predicting and better grasping the micro gap width range at this time during forging, thereby improving the processing efficiency.

[0019] Further, step S3 specifically comprises the following steps:

[0020] S31: heating the workpiece to a certain temperature;

[0021] S32: forming a micro gap by extruding and reducing the exhaust hole in the same direction through upsetting forging on a group of opposite surfaces of the workpiece parallel to the axis of the exhaust hole;

[0022] S33: removing the stress of the workpiece after forging.

[0023] Further, the heating method in step S31 is heating by a heating furnace or electromagnetic induction heating.

[0024] Further, the upsetting forging area in step S32 is an area containing all the exhaust holes and extending at least 20mm beyond the edge of the outermost exhaust hole.

[0025] Further, the way of removing the stress of the workpiece in step S33 is normalizing, and the workpiece is naturally cooled after forging.

[0026] It should be noted that the determination principle of the heating temperature of the workpiece is: the metal should have high plasticity and small deformation resistance in the heating temperature range, and the forged workpiece can obtain the desired organization and performance. For actual operation process, different metal materials are used for processing, and the optimal heating temperature is selected according to the forging characteristics of different metals and through repeated tests. After heating to a certain temperature, the workpiece is forged and processed.

[0027] It should be noted that the present application adopts a forging forming process. After heating the workpiece, the hot plasticity of the workpiece is utilized to upset and forge on a group of opposite surfaces of the exhaust hole. The opposite surfaces are opposite side surfaces parallel to the circumferential direction of the exhaust hole. The exhaust hole is extruded and deformed in the same direction and the port is reduced to form a micro slit. The forging force applied by forging should be controlled within the reasonable range of the hot plasticity of the workpiece metal under stress, so as to ensure that the exhaust hole is gradually extruded and deformed during forging, and avoid that the inner wall of the exhaust hole is extruded and fitted, the air passage is blocked and the processing fails due to excessive forging force. After the forging is completed, the physical properties of the workpiece can be improved through certain heat treatment. The normalizing process can refine the crystal grains of the steel under slightly faster cooling. Not only the strength can be satisfied, but also the toughness (AKV value) can be significantly improved, the cracking tendency of the component is reduced, the grain refinement and carbide distribution are uniformized, the stress of the workpiece is removed, and the comprehensive mechanical properties of the workpiece are greatly improved.

[0028] The present application also provides a micro-slit exhaust insert, which is processed by the above-mentioned processing method of the exhaust insert. It should be noted that the specific form of the exhaust insert obtained by the processing method of the exhaust insert of the present application includes but is not limited to the exhaust insert, the formed part with exhaust function, etc.

[0029] Compared with the prior art, the present application has the following advantages:

[0030] (1) The present application adopts a forging forming process to compress and lengthen the exhaust hole opening to form a slit-shaped micro slit. According to the fact that the circumference of the exhaust hole port does not change before and after forging, the width of the micro slit can be determined by measuring the length of the exhaust micro slit after forging. The deformation of the exhaust hole does not affect the air flow, but the air passage can be changed into a long and narrow slit. The width of the slit can be controlled below the overflow value of various die casting or injection molding materials. The width of the micro slit can be controlled in a very small range. The micro slit can well exhaust and release the residual pressure in the mold cavity, and can also prevent the overflow defect on the surface of the injection or die casting product.

[0031] (2) the present application is through unique, novel processing method, using the forging forming technology, for the industry first, realized the micro gap forming processing, this kind of processing method has originality and skill, processing method is simple and easy to operate, low cost, can be widely used in die casting industry and injection molding industry various exhaust insert production and processing. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 is the operation flow chart of embodiment 1 of the present application;

[0033] Figure 2 is the operation flow chart in embodiment 2 of the present application;

[0034] Figure 3 is the assembly drawing of bumper injection mold in embodiment 3 of the present application;

[0035] Figure 4 is the sectional view of exhaust insert in embodiment 3 of the present application.

[0036] The illustration mark is explained as follows:

[0037] 1-exhaust insert, 2-bumper injection mold. DETAILED DESCRIPTION

[0038] The present application will be further described below in conjunction with specific embodiments. Wherein, the drawings are only used for example description, and the representation is only schematic diagram, and not physical diagram, and can not be understood as the limitation of the present patent; in order to better illustrate the embodiment of the present application, some components of the drawings will be omitted, enlarged or reduced, and not represent the size of actual product; for those skilled in the art, it is understandable that some well-known structures in the drawings and their description can be omitted.

[0039] The same or similar reference numerals in the drawings of the embodiments of the present application correspond to the same or similar components; in the description of the present application, it is understood that if there are terms such as 'upper', 'lower', 'left', 'right' indicating the orientation or positional relationship is based on the orientation or positional relationship shown in the drawings, only for the convenience of describing the present application and simplifying the description, and not indicating or implying that the device or element indicated must have a particular orientation, a particular orientation and operation, therefore, the positional relationship described in the drawings is only used for example description, and can not be understood as the limitation of the present patent, for those skilled in the art, the specific meaning of the above terms can be understood according to the specific situation.

[0040] Embodiment 1

[0041] As shown in Figure 1 , a processing method of exhaust insert, specifically comprising the following steps:

[0042] S1: cutting and rough machining to obtain the required workpiece shape;

[0043] S2: machining an exhaust hole with a diameter of D on the workpiece using a drilling device;

[0044] S3: forging the workpiece by adopting a forging forming process, so that the exhaust hole is extruded to be smaller in the same direction and a micro slit is formed;

[0045] S4: measuring the length a of the micro slit and calculating the width b of the micro slit, until the target micro slit width range is reached, and if the calculated micro slit width b does not reach the target micro slit width range, repeating step S3;

[0046] S5: performing finish machining on the workpiece according to the part drawing requirements to obtain an exhaust insert with a micro slit.

[0047] The machining principle of the embodiment is that: the exhaust hole opening is compressed and elongated to form a slit-shaped micro slit by adopting a forging forming process. According to the fact that the circumference of the exhaust hole port before and after forging does not change, the width of the micro slit can be judged by measuring the length of the exhaust micro slit after forging. After the deformation of the exhaust hole, the air flow does not change, but the air passage becomes a long and narrow slit. The slit width can be controlled below the overflow value of various die casting or injection molding materials. The micro slit width can be controlled in a very small range. The micro slit can well exhaust and release the residual pressure in the mold cavity, and at the same time, it can eliminate the overflow defects on the surface of the injection or die casting product. The processing method is simple and easy to operate, the cost is low, and it can be widely applied to the production and processing of various exhaust inserts in the die casting industry and the injection molding industry.

[0048] In the embodiment, the target micro slit width range is 0.005mm~0.05mm.

[0049] It should be noted that for different product materials, the target micro slit width can be referred to the material overflow value as a basis. As shown in Table 1, the overflow values of commonly used injection or die casting materials ABS, PMMA, hard PVC, soft PVC, PE / HDPE / LDPE, PPO / PPE, PP, PP+GF / PP+TD, TPE / TPV / TPU, PA / PA6 / PA66, (PA / PA6 / PA66)+GF, POM / POM+GF, AL (aluminum alloy) are between 0.01mm~0.05mm. Therefore, for exhaust inserts used in different materials injection or die casting, the target micro slit width can be reasonably adjusted to be smaller than the overflow value of the material, so as to ensure good exhaust performance and not affect the appearance quality of the product.

[0050] Table 1: Overflow value of commonly used injection or die casting materials

[0051]

[0052] In this embodiment, the metal material of the workpiece is 45# steel, and step S3 specifically includes the following steps:

[0053] S31: heating the workpiece to 600±50°C by a heating furnace or electromagnetic induction;

[0054] S32: by upsetting the workpiece on a set of opposite surfaces parallel to the axis of the exhaust hole, the exhaust hole is extruded and reduced in size in the same direction to form a micro slit; the upsetting area is an area containing all the exhaust holes and extending at least 20mm beyond the edge of the outermost exhaust hole;

[0055] S33: after the forging is completed, the workpiece is naturally cooled, and normalizing is performed to remove the stress of the workpiece.

[0056] In this embodiment, before processing, the same metal workpiece material is tested by adjusting different forging temperature conditions and forging pressure for trial forging, so as to obtain reliable temperature data and forging force data, and the most suitable heating temperature and forging force are selected to avoid rework and scrap.

[0057] In this embodiment, the forging forming process is used, after heating the workpiece, the hot plasticity of the workpiece is used to upset the workpiece on a set of opposite surfaces parallel to the axis of the exhaust hole, which can be manually forged, and related forging tooling can be used for assistance, the opposite surfaces are opposite surfaces parallel to the circumferential direction of the exhaust hole, the exhaust hole is extruded and deformed in the same direction and the port is reduced, a micro slit is formed, the forging force applied by the forging is controlled within the reasonable range of the hot plasticity of the workpiece metal, which ensures that the exhaust hole is gradually extruded and deformed during the forging process, avoids the exhaust hole inner wall from being extruded and fitted, and the air passage is blocked due to excessive forging force, resulting in processing failure, and after the forging is completed, the physical properties of the workpiece can be improved by a certain heat treatment method, wherein the normalizing process can refine the crystal grains of the steel under slightly faster cooling, not only can satisfy the strength, but also can significantly improve the toughness (AKV value), reduce the cracking tendency of the component, refine the grains and uniformize the carbide distribution, remove the stress of the workpiece, and greatly improve the comprehensive mechanical properties of the workpiece.

[0058] In this embodiment, the relationship for measuring the micro slit width b in step S4 is: a=πD / 2-b; where D is the diameter of the exhaust hole, a is the length of the micro slit, and b is the width of the micro slit.

[0059] Table 2: Corresponding relationship between micro slit length and width

[0060]

[0061] It should be noted that, according to the embodiment, the length-width relationship of the micro slit can be converted into the quantity relationship shown in Table 2, the length of the micro slit after forging can be measured to quickly determine the width of the micro slit, and the quick determination of the size of the micro slit can meet the requirements of predicting and better mastering the width range of the micro slit during forging, thereby improving the processing efficiency.

[0062] The implementation of the embodiment is tested and experimented repeatedly, and innovatively adopts the forging forming technology to process the exhaust insert, and replaces the traditional exhaust hole with a micro slit to exhaust, so that the width of the micro slit can be controlled in a very small range, the micro slit can well exhaust and release the residual pressure in the mold cavity, and the overflow defect on the surface of the injection molded or die cast product can be eliminated. The unique and novel processing method of the embodiment is first created in the industry, realizes the forming and processing of the micro slit, and has originality and skill. The processing method is simple and easy to operate, has low cost, and can be widely applied to the production and processing of various exhaust inserts in the die casting industry and the injection molding industry.

[0063] Embodiment 2

[0064] As shown in Figure 2 the embodiment is similar to the embodiment 1, and the difference is that:

[0065] In the embodiment, after step S4 and before step S5, the step S41 of micro slit detection is further included, that is, the actual width of the micro slit of the exhaust insert with the micro slit and the ventilation condition are detected. If the actual width of the micro slit does not reach the target micro slit width range, steps S3 and S4 are repeated. If the micro slit cannot be ventilated, steps S2 to S4 are repeated.

[0066] In the embodiment, the actual width detection of the micro slit is the microscopic measurement, which can accurately measure whether the actual width of the micro slit reaches the target micro slit width.

[0067] In the embodiment, the ventilation condition detection of the micro slit is the visual detection or the air suction / drawing detection.

[0068] It should be noted that the micro slit width b is calculated during the forging process to quickly calibrate the current width range and facilitate the quick forging operation. After reaching the target micro slit width, the micro slit is detected by using a measuring tool, which is the actual detection of the target micro slit width, can accurately measure the specific width, and can eliminate the possible error of the calculation.

[0069] The other operation steps and principles of the embodiment are the same as those of the embodiment 1.

[0070] Embodiment 3

[0071] An exhaust insert 1 with a micro slit, taking the micro slit processing of the injection exhaust insert as an example, Figure 3Figure 2 is an assembly view of an injection mold for a bumper, in which the vent insert 1 of the present embodiment is embedded. Figure 3 In the dashed line range, there is a risk of gas trapping. In the mold design stage, the vent insert 1 of the present embodiment is designed in advance. The vent insert 1 is processed by the processing method of any one of the vent inserts described in Embodiments 1 or 2.

[0072] As shown in Figure 4 Figure 2, the vent insert 1 of the present embodiment is embedded in the injection mold 2 for the bumper. The target width of the micro slit is 0.01 mm. In the injection molding process, the gas trapped can be discharged to the outside of the mold cavity through the micro slit of the vent insert 1, thereby avoiding the formation of product gas trapping to cause quality problems.

[0073] Obviously, the above embodiments of the present application are merely exemplary and are not intended to limit the embodiments of the present application. Based on the above description, those of ordinary skill in the art can make other different forms of changes or modifications. Here, it is not necessary and impossible to exhaust all the embodiments. Any modification, equivalent replacement and improvement made within the spirit and principles of the present application shall be included in the protection scope of the claims of the present application.

Claims

1. A method of machining an exhaust insert, characterized by, Specifically comprising the following steps: S1: cutting and rough machining to obtain the desired workpiece shape; S2: using a hole opening device to process exhaust holes with a diameter of D on the workpiece; S3: using a forging forming process to forge the workpiece, so that the exhaust holes are extruded and reduced in the same direction to form micro-slits; S4: measuring the micro-slit length a and calculating the micro-slit width b until the target micro-slit width range is reached, if the measured micro-slit width b does not reach the target micro-slit width range, repeat step S3; S5: according to the requirements of the part drawing, the workpiece is finished to obtain the exhaust insert with micro-slits.

2. The method of claim 1, wherein, The target micro-slit width range is 0.005mm~0.05mm.

3. The method of claim 1, wherein the exhaust insert is made of a material selected from the group consisting of: steel, cast iron, and aluminum. After step S4 and before step S5, it further comprises step S41: micro-slit detection, detecting the actual width of the micro-slit of the exhaust insert with micro-slits and the ventilation condition, if the actual width of the micro-slit does not reach the target micro-slit width range, repeat steps S3 and S4, if the micro-slit cannot ventilate, repeat steps S2 to S4.

4. The method of claim 3, wherein the exhaust insert is formed from a material selected from the group consisting of: steel, cast iron, and aluminum. The actual width of the micro-slit is detected by a microscope, and the ventilation condition of the micro-slit is detected by visual observation or air suction / drainage detection.

5. The method of claim 1, wherein the exhaust insert is made of a material selected from the group consisting of: steel, cast iron, and aluminum. The calculation relationship of the micro-slit width b in step S4 is: a=πD / 2-b; where D is the diameter of the exhaust hole, a is the micro-slit length, and b is the micro-slit width.

6. The method of claim 1, wherein, The step S3 specifically comprises the following steps: S31: heating the workpiece to a certain temperature; S32: by upsetting forging the workpiece and the exhaust hole axis parallel to a set of opposite surfaces, the exhaust hole is extruded and reduced in the same direction to form a micro-slit; S33: after forging, remove the stress of the workpiece.

7. The method of claim 6, wherein the exhaust insert is formed by a process comprising: The heating method in step S31 is by heating furnace or electromagnetic induction heating.

8. The method of claim 6, wherein the exhaust insert is formed from a material selected from the group consisting of: steel, cast iron, and aluminum. The upsetting forging area in step S32 is an area that contains all exhaust holes and extends at least 20mm beyond the edge of the outermost exhaust hole.

9. The method of claim 6, wherein the exhaust insert is formed from a material selected from the group consisting of: steel, cast iron, and aluminum. The way to remove the stress of the workpiece in step S33 is normalizing, and the workpiece is naturally cooled after forging.

10. An exhaust insert with micro-slits, characterized in that, The exhaust insert is processed by the processing method of any one of claims 1-9. The exhaust insert is processed by the processing method of any one of claims 1-9.

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