A process for sand grain size optimization for casting compressor cylinder liner

Abstract

The application discloses a molding sand granularity optimization process for casting compressor cylinder seats, which comprises the following steps: setting an initial target value of molding sand granularity (AFS), feeding 100 / 200 mesh silica sand and 70 / 140 mesh silica sand into a new sand hopper in turns according to the requirement of the initial target value of the molding sand granularity (AFS), tracking and counting the sand sticking condition of the sound-absorbing cavities of the cylinder seats in the same period, determining the optimal molding sand granularity (AFS) value, and formulating a new standard of silica sand as 140 / 70 mesh silica sand and providing the silica sand supplier. The molding sand granularity is optimized, the sand sticking problem of the sound-absorbing cavities of the cylinder seats is obviously improved, and the silica sand supplier is provided with the new standard of the silica sand according to the optimized molding sand granularity, so that the silica sand supplier can make and directly provide the silica sand meeting the requirement, the silica sand mixing process is saved, the addition amount of the coal powder with the sand sticking prevention function in the molding sand process is reduced, and the casting material cost is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of molding sand, in particular to a molding sand granularity optimization process for casting compressor cylinder bases. BACKGROUND

[0002] The cylinder base is a core component of the compressor assembly, and the sound attenuation cavity thereof is a key part for the operation of the compressor, and the mechanical sand sticking on the sound attenuation cavity appearance will directly affect the working noise of the compressor.

[0003] Currently, 70 / 140 mesh silica sand is used in the casting production line, and the granularity (AFS) of the molding sand is controlled in the range of 60±5, and the sand sticking occurs when the sound attenuation cavity of the cylinder base is produced, and the sand sticking waste of the castings is high. SUMMARY

[0004] In view of the above technical problems in the related art, the present application provides a molding sand granularity optimization process for casting compressor cylinder bases, which can solve the above problems.

[0005] To achieve the above technical purposes, the technical solution of the present application is as follows:

[0006] A molding sand granularity optimization process for casting compressor cylinder bases, comprising the following steps:

[0007] S100, setting an initial target value of the molding sand granularity (AFS), wherein the initial target value of the molding sand granularity (AFS) is 68±N, wherein N is an integer and 1≤N≤5;

[0008] S200, according to the requirement of the initial target value of the molding sand granularity (AFS), the 100 / 200 mesh silica sand and the 70 / 140 mesh silica sand are sequentially fed into the new sand hopper;

[0009] S210, taking one week as a cycle, first, the 100 / 200 mesh silica sand is quantitatively fed into the new sand hopper for t consecutive days, and then the 70 / 140 mesh silica sand is quantitatively fed into the new sand hopper for 7-t consecutive days, and the feeding is alternated;

[0010] S220, the fed silica sand is mixed with the bentonite, the coal powder and the old sand as new sand to form the molding sand for casting the sound attenuation cavity of the cylinder base, the granularity change of the molding sand is detected twice a week, and the feeding days or the feeding amount of the 100 / 200 mesh silica sand and the 70 / 140 mesh silica sand are correspondingly increased or decreased according to the granularity change, so that the molding sand granularity (AFS) is controlled in the range of 68±N;

[0011] S230, tracking and counting the sand sticking conditions of the sound attenuation cavities of the cylinder bases in the same period;

[0012] S300, the optimal sand grain size (AFS) value is determined by verifying different N values in sequence by using steps S200-S230, and the final optimal sand grain size (AFS) value is 68±3;

[0013] S400, according to the optimal sand grain size (AFS), a new standard of silica sand is formulated as 140 / 70 mesh silica sand, and is provided to the silica sand supplier.

[0014] Further, the SiO2[A] of the 100 / 200 mesh silica sand is ≥90%, the AFS of the 100 / 200 mesh silica sand is 90-115, the clay content of the 100 / 200 mesh silica sand is ≤0.7%, the water content of the 100 / 200 mesh silica sand is ≤0.3%, the acid consumption value of the 100 / 200 mesh silica sand is ≤6ml, the ignition loss of the 100 / 200 mesh silica sand is ≤0.7%, the particle composition [B] of the 100 / 200 mesh silica sand is 100 # +140 # +200 # ≥90%, the particle shape of the 100 / 200 mesh silica sand is nearly round, and the angular coefficient of the 100 / 200 mesh silica sand is ≤1.2.

[0015] Further, the SiO2[A] of the 70 / 140 mesh silica sand is ≥90%, the AFS of the 70 / 140 mesh silica sand is 70±3, the clay content of the 70 / 140 mesh silica sand is ≤0.5%, the water content of the 70 / 140 mesh silica sand is ≤0.3%, the acid consumption value of the 70 / 140 mesh silica sand is ≤5ml, the ignition loss of the 70 / 140 mesh silica sand is ≤0.5%, the particle composition [B] of the 70 / 140 mesh silica sand is 70 # +100 # +140 # ≥90%, the particle shape of the 70 / 140 mesh silica sand is nearly round, and the angular coefficient of the 70 / 140 mesh silica sand is ≤1.2.

[0016] Further, the SiO2[A] of the 140 / 70 mesh silica sand is ≥90%, the AFS of the 140 / 70 mesh silica sand is 76±3, the clay content of the 140 / 70 mesh silica sand is ≤0.5%, the water content of the 140 / 70 mesh silica sand is ≤0.3%, the acid consumption value of the 140 / 70 mesh silica sand is ≤5ml, the ignition loss of the 140 / 70 mesh silica sand is ≤0.5%, the particle composition [B] of the 140 / 70 mesh silica sand is 70 # +100 # +140 # ≥90%, the particle shape of the 140 / 70 mesh silica sand is nearly round, and the angular coefficient of the 70 / 140 mesh silica sand is ≤1.2.

[0017] Further, in the verification of different N values by using steps S200-S230, only the change of the sand grain size (AFS) value is changed, and other process conditions remain unchanged.

[0018] The application has the following beneficial effects: the sand grain size is optimized, the problem of sand sticking in the cylinder block muffling cavity is obviously improved, and the optimized sand grain size is used to formulate a new standard for the silica sand type, so that the silica sand supplier can make and directly provide the silica sand meeting the requirements, thereby saving the silica sand mixing process, reducing the amount of coal powder added in the sand process for preventing sand sticking, and reducing the cost of casting materials. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the application will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art belong to the scope of protection of the application.

[0020] The sand grain size optimization process for casting a compressor cylinder block according to the embodiment of the application comprises the following steps: setting an initial target value of the sand grain size (AFS), setting the initial target value of the sand grain size (AFS) as 68±3; according to the requirement of the initial target value of the sand grain size (AFS), feeding 100 / 200 mesh silica sand and 70 / 140 mesh silica sand into the new sand hopper alternately; taking one week as a cycle, first feeding 4 bags (6 tons) of 100 / 200 mesh silica sand into the new sand hopper every day for 3-4 days, and then feeding 4 bags (6 tons) of 70 / 140 mesh silica sand into the new sand hopper every day for 3-4 days, so as to alternately feed the silica sand; mixing the fed silica sand as new sand with bentonite, coal powder and old sand as the sand for casting the cylinder block muffling cavity, detecting the change of the sand grain size twice a week (the detection results are shown in Table 1, and the average value is 68.82), increasing or decreasing 1 day of feeding of the 100 / 200 mesh silica sand and the 70 / 140 mesh silica sand according to the change of the sand grain size, so as to control the sand grain size (AFS) in the range of 68±3; tracking and counting the sand sticking condition of the cylinder block muffling cavity in the same period, and when the sand grain size (AFS) value is 68±3, the sand sticking in the cylinder block muffling cavity is obviously improved.

[0021] Table 1

[0022]

[0023] The verification sequence of the initial target value of the molding sand granularity (AFS) is 68±1, 68±2, 68±3, 68±4, 68±5 in turn. When the initial target value of the molding sand granularity (AFS) is 68±4, the number of unqualified silencing cavity sand sticking of the cylinder block is relatively large, and the effect is relatively poor. Therefore, the molding sand granularity (AFS) is finally selected as 68±3 (the silencing cavity sand sticking of the cylinder block is obviously improved, and the range is relatively large, which is beneficial to process control). According to the range requirement of the molding sand granularity (AFS), a new standard of silica sand is 140 / 70 mesh silica sand, which is provided to the silica sand supplier. The silica sand manufacturer prepares the silica sand meeting the requirement according to the new standard requirement and provides it to the applicant. The 140 / 70 mesh silica sand is directly used for the casting of the cylinder block to replace the mixed sand (100 / 200 mesh and 70 / 140 mesh granularity silica sand) in production, which avoids the complicated operation mode of adding 100 / 200 mesh and 70 / 140 mesh granularity silica sand for several days in the past. Moreover, the molding sand granularity fluctuates greatly and is unstable, which leads to the occurrence of silencing cavity sand sticking during the production of the cylinder block. The addition amount of the coal powder with the anti-sand sticking effect in the molding sand process can be reduced, and the casting material cost can be reduced. At the same time, because the molding sand granularity is fine, the surface roughness of the casting is reduced, the surface finish is improved, and the amount of steel shot for shot blasting of the casting is reduced.

[0024] The technical requirements for purchasing silica sand are shown in Table 2.

[0025] Table 2

[0026]

[0027] The above only describes the preferred embodiments of the present application and is not used to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A molding sand particle size optimization process for casting compressor cylinder seats, characterized in that, Includes the following steps: S100. Set the initial target value for molding sand particle size (AFS). The initial target value for molding sand particle size (AFS) is 68±N, where N is an integer and 1≤N≤5. S200. According to the initial target value of molding sand particle size (AFS), feed 100 / 200 mesh silica sand and 70 / 140 mesh silica sand into the new sand hopper in turn. S210. Using a week as a cycle, first feed 100 / 200 mesh silica sand into the new sand hopper for t days, then feed 70 / 140 mesh silica sand into the new sand hopper for 7-t days, and so on, alternating feeding. S220. The silica sand fed in is mixed with bentonite, coal powder and old sand as new sand to be used as molding sand for casting the cylinder seat muffler cavity. The particle size change of the molding sand is detected twice a week. According to the particle size change, the number of days or the amount of 100 / 200 mesh silica sand and 70 / 140 mesh silica sand are increased or decreased accordingly to keep the particle size of molding sand (AFS) within the range of 68±N. S230. Track and statistically analyze the sand adhesion situation in the cylinder block muffler cavity during the same period; S300. Using steps S200 to S230, verify different N values ​​sequentially to determine the optimal molding sand particle size (AFS) value. The final optimal molding sand particle size (AFS) value is 68±3. S400. Based on the optimal molding sand particle size (AFS), a new standard for silica sand is established as 140 / 70 mesh silica sand, and provided to silica sand suppliers. The 140 / 70 mesh silica sand has the following characteristics: SiO2[A] ≥ 90%; AFS ≥ 76 ± 3; mud content ≤ 0.5%; moisture content ≤ 0.3%; acid consumption ≤ 5 ml; loss on ignition ≤ 0.5%; and particle size distribution [B] ≥ 70. # +100 # +140 # ≥90%, the particle shape of the 140 / 70 mesh silica sand is nearly round, and the angularity coefficient of the 70 / 140 mesh silica sand is ≤1.

2.

2. The molding sand particle size optimization process for casting compressor cylinder seats according to claim 1, characterized in that, The 100 / 200 mesh silica sand has SiO2[A] ≥ 90%, an AFS of 90-115, a mud content ≤ 0.7%, a moisture content ≤ 0.3%, an acid consumption value ≤ 6 ml, a loss on ignition ≤ 0.7%, and a particle size distribution[B] of 100 / 200 mesh silica sand. # +140 # +200 # ≥90%, the particle shape of the 100 / 200 mesh silica sand is nearly round, and the angularity coefficient of the 100 / 200 mesh silica sand is ≤1.

2.

3. The molding sand particle size optimization process for casting compressor cylinder seats according to claim 1, characterized in that, The 70 / 140 mesh silica sand has SiO2[A] ≥ 90%, an AFS of 70±3, a mud content of ≤ 0.5%, a moisture content of ≤ 0.3%, an acid consumption value of ≤ 5 ml, a loss on ignition of ≤ 0.5%, and a particle size distribution[B] of 70. # +100 # +140 # ≥90%, the particle shape of the 70 / 140 mesh silica sand is nearly round, and the angularity coefficient of the 70 / 140 mesh silica sand is ≤1.

2.

4. The molding sand particle size optimization process for casting compressor cylinder seats according to claim 1, characterized in that, When verifying different N values ​​using steps S200 to S230, only the AFS (Advanced Sand Size) value is changed, while other process conditions remain unchanged.

Images