阅读说明：本技术 一种发动机缸体型腔模具加工工艺 (Machining process of engine cylinder body cavity die ) 是由 林邦远 肖伟雄 周希旺 于 2019-12-02 设计创作，主要内容包括：本发明公开了一种发动机缸体型腔模具加工工艺,包括：下料并粗加工,然后调质、精加工,分别得到定模和动模,其中,定模的里侧面中部开设成型腔；下料并通过粗加工得到模芯坯件,将模芯坯件进一步进行热处理和精加工,得到模芯；其中,所述热处理包括：将模芯坯件连续加热至980-1030℃,随后使用油冷或气冷将模芯坯件冷却至420-450℃后空冷,对空冷后的模芯坯件回火,使其硬度为45-48HRC；将模芯组装固定于定模的成型腔内；将定模与动模合模,检查贴合度。本发明使模芯的微观组织转变为马氏体,减少或避免沿晶界析出的碳化物、贝氏体和残余奥氏体,使模芯硬度均匀,提高其成型和脱膜效果；将定模与动模合模,检查贴合度,可以提高合模效果,提高铸造质量。(The invention discloses a processing technology of a cavity die of an engine cylinder, which comprises the following steps: blanking and rough machining, then tempering and finish machining to respectively obtain a fixed die and a movable die, wherein a forming cavity is formed in the middle of the inner side surface of the fixed die; blanking and obtaining a mold core blank through rough machining, and further carrying out heat treatment and finish machining on the mold core blank to obtain a mold core; wherein the heat treatment comprises: continuously heating the mold core blank to 980-1030 ℃, then cooling the mold core blank to 420-450 ℃ by using oil cooling or air cooling, then air cooling, and tempering the air-cooled mold core blank to ensure that the hardness of the mold core blank is 45-48 HRC; assembling and fixing a mold core in a molding cavity of the fixed mold; and (5) closing the fixed die and the movable die, and checking the fitting degree. The invention enables the microstructure of the mold core to be transformed into martensite, reduces or avoids carbide, bainite and residual austenite precipitated along the grain boundary, enables the hardness of the mold core to be uniform, and improves the forming and demoulding effects; the fixed die and the movable die are matched, and the fitting degree is checked, so that the matching effect can be improved, and the casting quality is improved.)

1. A machining process for a cavity die of an engine cylinder block is characterized by comprising the following steps of:

blanking and rough machining, then tempering and finish machining to respectively obtain a fixed die and a movable die, wherein a forming cavity is formed in the middle of the inner side surface of the fixed die;

blanking and obtaining a mold core blank through rough machining, and further carrying out heat treatment and finish machining on the mold core blank to obtain a mold core; wherein the heat treatment comprises: continuously heating the mold core blank to 980-1030 ℃, then cooling the mold core blank to 420-450 ℃ by using oil cooling or air cooling, then air cooling, and tempering the air-cooled mold core blank to ensure that the hardness of the mold core blank is 45-48 HRC;

assembling and fixing a mold core in a molding cavity of the fixed mold;

and (5) closing the fixed die and the movable die, and checking the fitting degree.

2. The engine block cavity die machining process of claim 1, wherein: the blanking and rough machining comprises the following steps: 45# or 50# steel is selected for blanking and is roughly processed to form a blank and a forming cavity.

3. The engine block cavity die machining process according to claim 2, characterized in that: the quenching and tempering and finish machining comprises the following steps: tempering to a hardness of 28-32HRC, and finishing the molding cavity, removing burrs and polishing.

4. The engine block cavity die machining process of claim 1, wherein: blanking and obtaining a mold core blank through rough machining, comprising: h13 steel is selected for blanking, a rudiment is formed through bench work processing and numerical control processing, and finishing allowance is reserved to obtain a mold core blank.

5. The engine block cavity die machining process of claim 4, wherein: said allowance for finishing comprises: and reserving a finishing allowance of 1-1.8 mm.

6. The engine block cavity die machining process of claim 5, wherein: the further heat treatment and finishing of the mold core blank comprises: removing the excess material and burrs, and polishing.

7. The engine block cavity die machining process according to any one of claims 1 to 6, wherein: the check fitting degree includes: and checking the fitting degree to ensure that the clearance between the fixed die and the movable die after the fixed die and the movable die are assembled is less than or equal to 0.05 mm.

Technical Field

The invention relates to the technical field of cavity mold production, in particular to a machining process of a cavity mold of an engine cylinder body.

Background

The cylinder body of the automobile engine is a framework of the engine, and main parts are installed in the cylinder body. Since the cylinder block of the automobile engine has a complex structure and is difficult to mold and cannot be manufactured by an assembly method, a cavity die is generally used for casting.

The existing engine cylinder body cavity die has the problems of poor die assembly precision and poor die core forming and demoulding effects, so that the cast engine cylinder body has high defective rate and cannot meet the standard requirements.

Disclosure of Invention

Based on the above, the invention aims to provide a machining process of a cavity die of an engine block.

The invention relates to a processing technology of a cavity die of an engine cylinder block, which comprises the following steps:

blanking and rough machining, then tempering and finish machining to respectively obtain a fixed die and a movable die, wherein a forming cavity is formed in the middle of the inner side surface of the fixed die;

blanking and obtaining a mold core blank through rough machining, and further carrying out heat treatment and finish machining on the mold core blank to obtain a mold core; wherein the heat treatment comprises: continuously heating the mold core blank to 980-1030 ℃, then cooling the mold core blank to 420-450 ℃ by using oil cooling or air cooling, then air cooling, and tempering the air-cooled mold core blank to ensure that the hardness of the mold core blank is 45-48 HRC;

assembling and fixing a mold core in a molding cavity of the fixed mold;

and (5) closing the fixed die and the movable die, and checking the fitting degree.

According to the processing technology of the engine cylinder body cavity die, the fixed die, the movable die and the die core are respectively and independently processed, so that the processing precision of the fixed die, the movable die and the die core is improved; continuously heating the mold core blank to 980-1030 ℃, cooling the mold core blank to 420-450 ℃ by using oil cooling or air cooling, then performing air cooling, tempering the air-cooled mold core blank to ensure that the hardness of the mold core blank is 45-48HRC, and after heat treatment, converting the microstructure of the mold core into martensite, reducing or avoiding carbide, bainite and residual austenite precipitated along the grain boundary, ensuring that the hardness of the mold core is uniform, improving the molding and demolding effects of the mold core, and ensuring that the hardness and the strength of the mold core after tempering are good; the fixed die and the movable die are matched, and the fitting degree is checked, so that the matching effect can be improved, and the casting quality is improved.

In one embodiment, the blanking and roughing comprises: 45# or 50# steel is selected for blanking and is roughly processed to form a blank and a forming cavity.

In one embodiment, the conditioning, finishing, comprises: tempering to a hardness of 28-32HRC, and finishing the molding cavity, removing burrs and polishing.

In one embodiment, the blanking and rough machining produces a core blank comprising: h13 steel is selected for blanking, a rudiment is formed through bench work processing and numerical control processing, and finishing allowance is reserved to obtain a mold core blank.

In one embodiment, the leaving of a finishing allowance comprises: and reserving a finishing allowance of 1-1.8 mm.

In one embodiment, the further heat treating and finishing of the core blank comprises: removing the excess material and burrs, and polishing.

In one embodiment, the checking a degree of fitting includes: and checking the fitting degree to ensure that the clearance between the fixed die and the movable die after the fixed die and the movable die are assembled is less than or equal to 0.05 mm.

The processing technology of the engine cylinder body cavity die has the beneficial effects that:

(1) the fixed die, the movable die and the die core are respectively and independently processed, and the processing precision of the fixed die, the movable die and the die core is improved.

(2) The method comprises the steps of continuously heating a mold core blank to 980-1030 ℃, cooling the mold core blank to 420-450 ℃ by using oil cooling or air cooling, then performing air cooling, tempering the air-cooled mold core blank to ensure that the hardness of the mold core blank is 45-48HRC, converting the microstructure of a mold core into martensite after heat treatment, reducing or avoiding carbide, bainite and residual austenite precipitated along a crystal boundary, ensuring that the hardness of the mold core is uniform, improving the molding and demolding effects of the mold core, and ensuring that the hardness and the strength of the mold core after tempering are good.

(3) The fixed die and the movable die are matched, and the fitting degree is checked, so that the matching effect can be improved, and the casting quality is improved.

(4) The machining process of the engine cylinder cavity die is simple in machining process, high in machining precision and good in comprehensive performance of the die core.

Detailed Description

The implementations described in the exemplary embodiments below are not intended to represent all implementations consistent with the present disclosure. Rather, they are merely examples of methods consistent with certain aspects of the present disclosure, as detailed in the appended claims.

The terminology used in the present disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used in this disclosure and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

The invention relates to a processing technology of a cavity die of an engine cylinder block, which comprises the following steps:

and step S1, blanking and rough machining, then quenching and tempering, and finish machining to respectively obtain a fixed die and a movable die, wherein the middle part of the inner side surface of the fixed die is provided with a forming cavity.

In this step, the blanking and rough machining includes: 45# or 50# steel is selected for blanking and is roughly processed to form a blank and a forming cavity.

The quenching and tempering and finish machining comprises the following steps: tempering to a hardness of 28-32HRC, and finishing the molding cavity, removing burrs and polishing.

Step S2, blanking, obtaining a mold core blank through rough machining, and further performing heat treatment and finish machining on the mold core blank to obtain a mold core; wherein the heat treatment comprises: continuously heating the mold core blank to 980-1030 ℃, cooling the mold core blank to 420-450 ℃ by using oil cooling or air cooling, then air cooling, and tempering the air-cooled mold core blank to ensure that the hardness of the mold core blank is 45-48 HRC.

In this step, the unloading obtains the mold core blank through rough machining, includes: h13 steel is selected for blanking, a rudiment is formed through bench work processing and numerical control processing, and finishing allowance is reserved to obtain a mold core blank.

The H13 steel has excellent heat resistance, wear resistance, strength and hardness, and is suitable for use as casting mold material.

Said allowance for finishing comprises: and reserving a finishing allowance of 1-1.8 mm. The left finishing allowance can provide the machining allowance for the subsequent polishing.

The left finishing allowance is determined according to the size of the mold core, and under the normal condition, the small and medium mold cores leave the finishing allowance of 1-1.4mm, and the large mold cores leave the finishing allowance of 1.4-1.8 mm.

The method comprises the steps of continuously heating a mold core blank to 980-1030 ℃, cooling the mold core blank to 420-450 ℃ by using oil cooling or air cooling, then performing air cooling, tempering the air-cooled mold core blank to ensure that the hardness of the mold core blank is 45-48HRC, converting the microstructure of a mold core into martensite after heat treatment, reducing or avoiding carbide, bainite and residual austenite precipitated along a crystal boundary, ensuring that the hardness of the mold core is uniform, improving the molding and demolding effects of the mold core, and ensuring that the hardness and the strength of the mold core after tempering are good.

The heat treatment can ensure the hardness and the strength of the mold core, improve the stability, the wear resistance, the corrosion resistance and the fatigue resistance of the mold core, and play an important role in the service life of the mold core.

The further heat treatment and finishing of the mold core blank comprises: removing the excess material and burrs, and polishing.

The polishing purposes are two: one is to increase the smoothness and make the surface smooth and beautiful, and the other is to make the product easy to demould. Polishing generally involves grinding the surfaces of the molding cavity and the mold core using flint, file, oilstone, sand paper, pneumatic tools, ultrasonic instruments, and the like.

And step S3, assembling and fixing the mold core in the molding cavity of the fixed mold.

In step S4, the fixed mold and the movable mold are closed, and the degree of adhesion is checked.

In this step, the inspecting a degree of fitting includes: and checking the fitting degree to ensure that the clearance between the fixed die and the movable die after the fixed die and the movable die are assembled is less than or equal to 0.05 mm. The clearance between the fixed die and the movable die after die assembly is less than or equal to 0.05mm, so that the die assembly effect can be improved, and the casting quality can be improved.

The processing technology of the engine cylinder body cavity die has the beneficial effects that:

(1) the fixed die, the movable die and the die core are respectively and independently processed, and the processing precision of the fixed die, the movable die and the die core is improved.

(2) The method comprises the steps of continuously heating a mold core blank to 980-1030 ℃, cooling the mold core blank to 420-450 ℃ by using oil cooling or air cooling, then performing air cooling, tempering the air-cooled mold core blank to ensure that the hardness of the mold core blank is 45-48HRC, converting the microstructure of a mold core into martensite after heat treatment, reducing or avoiding carbide, bainite and residual austenite precipitated along a crystal boundary, ensuring that the hardness of the mold core is uniform, improving the molding and demolding effects of the mold core, and ensuring that the hardness and the strength of the mold core after tempering are good.

(3) The fixed die and the movable die are matched, and the fitting degree is checked, so that the matching effect can be improved, and the casting quality is improved.

(4) The machining process of the engine cylinder cavity die is simple in machining process, high in machining precision and good in comprehensive performance of the die core.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention.