Production method of lubricating pump

Abstract

The invention discloses a production method of a lubricating pump. The production method of the lubricating pump comprises a machining method of the pump shell, and the machining method of the pump shell comprises the following steps that models are manufactured, specifically, a foam plastic model and a casting head model are manufactured; model clustering is conducted, specifically, the foam plastic model and the casting head model are combined and bonded together, and a model cluster is formed; coating the model, selecting a coating, adding water into a coating stirrer for stirring to obtain a proper viscosity, and coating the coating on the model cluster; the model is dried, specifically, the coated model cluster is put into drying equipment to be dried at the temperature of 40-60 DEG C; smelting and pouring are conducted, liquid metal is poured into the model cluster, and after molten metal is cooled and hardened, the wax mold is made to fall off from the surface of the pump shell blank to form the pump shell blank; and finish machining is conducted, specifically, the pump shell blank is subjected to finish machining. In the pump shell machining process, by controlling the quality of molten metal and the pouring speed, the situation that the instantaneous contact area of the molten metal and the model cluster is too large is prevented, and it is guaranteed that the molten metal level has a certain rising speed.

Description

Technical Field

[0001] The invention relates to the technical field of pump production methods, in particular to a production method for a lubrication pump. Background Art

[0002] The lubrication pump is the main component of the intelligent centralized lubrication system, which mainly includes an oil tank and a pump head assembly. The pump head assembly is equipped with a drive device, a cam assembly and a plunger assembly used in conjunction with the cam assembly. Each plunger assembly is an independent oil pumping unit, which is connected to the oil pipe to lubricate each lubrication point.

[0003] The pump casing is an important component of the lubrication pump. The volute of this component is used to install the impeller and connect the internal space of the pump body with the external pipeline. In order to ensure the reliable and beautiful connection and the sealing of the pump body, the pump casing needs to have higher precision requirements. Therefore, it is necessary to provide a high-precision pump casing production method. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a production method of a lubrication pump.

[0005] To achieve the above object, the technical solution of a production method of a lubrication pump of the present invention is as follows:

[0006] A method for producing a lubrication pump includes a method for processing a pump casing, wherein the method for processing the pump casing includes the following steps:

[0007] Model making, making foam models and pouring and riser models;

[0008] Model clustering: the foam model and the pouring and rising model are combined and bonded together to form a model cluster;

[0009] For model coating, select special paint, add water and stir it in a paint mixer to obtain the appropriate viscosity, and then apply the paint on the model cluster;

[0010] Model drying: put the coated model cluster into the drying equipment and dry it at 40-60℃;

[0011] Melting and pouring, pouring liquid metal into the model cluster, after the liquid metal cools and hardens, the wax model falls off from the surface of the pump casing blank to form the pump casing blank;

[0012] Before pouring, the amount of molten metal poured is controlled to be M, and during pouring, the pouring speed is controlled to be V.

[0013] M = V*D / F, where: M-mass of molten metal filled per unit time (kg / s), V-total volume of casting and runner (m3), D-density of molten metal (kg / m3), F-casting pouring time (s);

[0014] v = √2gh, where: v-initial velocity of molten metal (m / s), g-acceleration due to gravity (9.8m / s2), h-height of ladle from pouring head (m);

[0015] Finishing: finish machining the pump casing blank.

[0016] As a further improvement to the above technical solution, the model making step includes the following steps:

[0017] Pre-foaming, adding foam beads into the mold and pre-foaming to expand the beads to a certain size;

[0018] Maturation: the pre-foamed foam beads are placed in a dry and ventilated silo for a certain period of time, and the aging time is 10-45 hours;

[0019] Foam molding, fill the pre-foamed and matured foam beads into the cavity of the metal mold, heat it, and must be cooled before demolding to make the model cool down to below the softening temperature. The model will be demolded after hardening and shaping.

[0020] As a further improvement to the above technical solution, the mold is preheated to 100°C, cooled by spraying water on the back of the mold to quickly cool the mold to 40°C to 50°C, and then the mold is blown out with compressed air.

[0021] As a further improvement of the above technical solution, water vapor is introduced into the mold after the bubble beads fill the cavity. The water vapor enters from one side of the mold through the air inlet and is discharged from the other side. Under the action of water vapor, the bubble beads soften and expand, fill the gaps between the bubble beads and stick to each other. After the bubble beads are melted, water vapor is blown into the mold from both sides. The water vapor temperature is controlled at 120°C and the pressure is controlled at 0.15MPa.

[0022] As a further improvement to the above technical solution, the finishing step includes the following steps:

[0023] Blank profiling: buckle the pump casing blank on the profiling die, make the inner end surface of the pump casing blank fit with the reference surface of the profiling die, and use pressure equipment to apply a certain pressure to the pump casing blank;

[0024] Rough turning of the pump housing, machining the outer end face of the pump body blank and the profile on the outer end face, and machining the circumference of the blank;

[0025] Semi-finishing machining: remove the pump casing and reinstall it with the outer end face as the reference surface, use the center inner hole as the reference hole, and finish the inner end face and the inner end face profile;

[0026] CNC milling, taking the outer end face of the pump casing as the reference surface, finishing the inner end face of the pump casing and the sealing ring installation groove, and finishing the profile groove on the inner end face of the pump casing;

[0027] Finish machining, finish machining all unfinished surfaces on the outer end face of the pump casing, and finish machining the center inner hole of the pump casing.

[0028] As a further improvement to the above technical solution, during the pouring process, h is controlled to be between 0.05 and 0.15 m to prevent the molten metal from cooling, oxidizing and splashing.

[0029] As a further improvement to the above technical solution, the foam beads are expandable polystyrene resin beads.

[0030] The present invention provides a production method of a lubrication pump, which has the following beneficial effects compared with the prior art:

[0031] The traditional lubrication pump has a problem of poor processing accuracy due to the difficulty of core extraction during the casting process of the pump casing. The pump casing processing method of the present invention adopts lost foam casting technology with great advantages. During the filling process, the high-temperature molten metal contacts the plastic white mold, so that the white mold is liquefied, dissolved, and gasified in a very short time. If the area of ​​the white mold that the front end of the metal liquid surface contacts is too large in a short time, a large amount of gas will be instantly generated. These gases will not have time to overflow and will be sprayed back to cause defects such as wrinkles. The white mold will take away a large amount of heat during the liquefaction, gasification and decomposition process, so that the temperature of the front end of the molten metal drops rapidly. If the contact area between the molten metal and the white mold is too small, slow pouring will occur, and the molten metal will be locally cold, which is prone to defects such as cold shut and shrinkage. In the process of processing the pump casing, the production method of the lubrication pump of the present invention controls the quality of the molten metal and the pouring speed, thereby preventing the molten metal from having too large an instantaneous contact area with the model cluster, and ensuring that the molten metal surface has a certain rising speed. The pouring speed is the same as the speed of the liquefied, gasified and decomposed white mold by heat, which prevents the molten metal from being cut off and causing isolated liquid phases or box collapse defects, thereby improving the processing accuracy of the pump casing. In addition, the pump casing production method of the present invention avoids the occurrence of blind corners or horizontal blind holes, so that the pump casing is conducive to sand filling and compaction, thereby reducing the consumption of molten metal.

[0032] The pump casing processing method of the present invention uses a profiling mold and a pressure device to calibrate the shape of the pump casing blank before processing the pump casing blank, which can prevent the pump casing blank from being deformed too much during casting, improve the processing accuracy of the pump casing processing, and reduce the reserved processing amount of the pump casing during casting, thereby reducing the time required for the pump casing blank to be processed into place, thereby greatly improving the processing efficiency of the pump casing. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is an operation flow chart of the pump casing processing method of the present invention;

[0034] Figure 2 It is the operation flow chart of the foaming molding in the present invention;

[0035] Figure 3 It is an operation flow chart of finishing in the present invention. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0037] A specific embodiment of the production method of the lubrication pump of the present invention is as follows: Figure 1-Figure 3 As shown, the method for processing a pump casing includes the following steps: model making, model clustering, model coating, model drying, smelting and pouring, and fine processing.

[0038] Model making includes the following steps:

[0039] Pre-foaming, adding foam beads into the mold and pre-foaming to expand the beads to a certain size;

[0040] Maturation: the pre-foamed foam beads are placed in a dry and ventilated silo for a certain period of time, and the aging time is 10-45 hours;

[0041] Foam molding, fill the pre-foamed and matured foam beads into the cavity of the metal mold, heat it, and must be cooled before demolding to make the model cool down to below the softening temperature. The model will be demolded after hardening and shaping.

[0042] According to the lost foam casting process and characteristics, the pump casing processing method should first ensure the casting molding and minimize casting defects to ensure the quality of the casting. The pump casing processing method should be able to show its high precision, smooth surface, clear contour and other characteristics.

[0043] The process of foaming molding is: preheating → filling → steam → cooling → demolding. The mold must be preheated to 100℃, and the cooling method is to spray water on the back of the mold to make the mold cool quickly to 40℃~50℃, and then blow out the pattern with compressed air. Due to the low strength of the pattern, the correct demolding method must be selected to avoid deformation or damage to the pattern. The water vapor temperature is controlled at about 120℃ and the pressure is 0.15MPa. During molding, many problems will occur if the mold is not filled. The exhaust of the mold must ensure that the gas in the cavity is discharged smoothly, and the feeding port must be adjusted to a suitable position to facilitate the pre-expanded beads to fill the cavity. After the cavity is filled with beads, steam begins to pass. The steam enters from one side of the mold through the air inlet and is discharged from the other side. Under the action of steam, the beads soften and expand, fill the gaps between the beads and adhere to each other. After the beads are melted inside, steam should be blown into the mold from both sides immediately to increase the pressure, increase the temperature of the mold surface, and further expand the beads. This process must be cautious to prevent overburning from causing the beads on the surface of the model to collapse.

[0044] In the model clustering step, the foam model and the pouring and riser model are bonded together to form a model cluster. In the bonding process, attention should be paid to the selection of the adhesive. The adhesive should not only have low gas emission and sufficiently high strength, but also have relatively fast drying performance to meet the requirements of large-scale production. The adhesive used is a water-soluble polyvinyl acetate solution. Although it has high bonding strength, good storage performance and low cost, it pollutes the environment. The adhesive should be used as little as possible to reduce casting defects, because a considerable part of the waste of lost foam castings is related to the bonding surface problems of the model. A better design is to avoid using complex bonding surfaces and multiple bonding as much as possible.

[0045] In the model coating step, a special coating is selected, water is added to the coating mixer and stirred to obtain a suitable viscosity, the stirred coating is put into a container, and the model group is coated by dipping, brushing, pouring and spraying, and at least twice, so that the coating thickness is 0.5-2mm, and then dried at 40-50°C.

[0046] In the melting and pouring step, the liquid metal is poured into the model cluster. After the molten metal is cooled and hardened, the wax pattern is dropped from the surface of the pump casing blank to form the pump casing blank. Before pouring, the pouring amount of the molten metal is controlled to be M, and the pouring speed is controlled to be V during the pouring process.

[0047] M = V*D / F, where: M-the mass of the metal liquid filled per unit time (kg / s), V-the total volume of the casting and runner (m 3 ), D-metal density (kg / m 3 ), F-casting pouring time (s).

[0048] v = √2gh, where: v-initial velocity of the molten metal (m / s), g-gravitational acceleration (9.8m / s 2 ), h-the height of the ladle from the pouring head (m). In actual pouring production, in order to prevent the cooling oxidation and splashing of the molten metal, the distance between the ladle and the pouring cup is generally 0.05-0.15m. In this embodiment, h is 0.1m.

[0049] The finishing steps include the following steps: blank correction, pump body rough turning, semi-finishing turning, CNC milling, CNC milling flipping and finishing turning.

[0050] In the blank shaping step, the pump casing blank is buckled on the shaping mold so that the inner end surface of the pump casing blank is kept in contact with the reference surface of the shaping mold, and a certain pressure is applied to the pump casing blank using a pressure device.

[0051] In the rough turning step of the pump casing, after the contour of the pump casing blank is aligned, the center inner hole of the rough-machined blank is used as a positioning hole, the outer end face of the pump casing blank and the profile on the outer end face are machined, and the circumference of the blank is machined to reduce the amount of fine machining, thereby reducing the subsequent fine machining time and stress deformation after fine machining.

[0052] In the semi-finishing machining step, the pump casing is removed and reinstalled with the outer end face as the reference surface, the circumference of the pump casing is used for alignment, the center inner hole is used as the reference hole, and the inner end face and the upper profile of the inner end face are finely machined.

[0053] In the CNC milling process, the outer end face of the pump casing is pressed downward and fixed on the workbench, and the outer end face of the pump casing is used as the reference surface to fine-machine the inner end face of the pump casing and the sealing ring installation groove, and the profile groove on the inner end face of the pump casing is fine-machined, and multiple installation threaded holes are made on the circumference of the pump casing;

[0054] In the CNC milling flipping processing step, the machine tool worktable and the pump casing are flipped 90° at the same time, so that the end face of the pump casing at the water outlet faces upward, the end face of the pump casing at the water outlet is processed, and multiple screw holes are processed on the end face at the water outlet.

[0055] In the finishing step, the pump casing is installed and fixed with the inner end face as a reference, all the unfinished profiles on the outer end face of the pump casing are finished, and the central inner hole of the pump casing is finished.

[0056] In the casting process of the pump casing of the traditional lubrication pump, there will be problems such as difficulty in extracting the core. The pump casing processing method of the present invention adopts the lost foam casting technology and has great advantages. During the filling process, the high-temperature molten metal contacts the plastic white mold, causing the white mold to liquefy, dissolve, and gasify and overflow in a very short time. If the area of ​​the white mold that the front end of the metal liquid contacts is too large in a short time, a large amount of gas will be instantly generated. These gases will not have time to overflow and will spray back to cause defects such as wrinkles. The white mold will take away a large amount of heat during the liquefaction, gasification and decomposition process, causing the temperature of the front end of the molten metal to drop rapidly. If the contact area between the molten metal and the white mold is too small, slow pouring will occur, and the molten metal will have a local cold zone, which is prone to defects such as cold shut and shrinkage. In the process of processing the pump casing, the production method of the lubrication pump of the present invention controls the quality of the molten metal and the pouring speed, thereby preventing the molten metal from having an excessively large instantaneous contact area with the model cluster, and ensuring that the molten metal surface has a certain rising speed. The pouring speed is the same as the speed of the liquefied, gasified and decomposed white mold by heat, preventing the molten metal from being interrupted and causing isolated liquid phases or box collapse defects. In addition, the pump casing production method of the present invention avoids the occurrence of blind corners or horizontal blind holes, which facilitates the compaction of sand filling in the casting and reduces the consumption of molten metal.

[0057] The pump casing processing method of the present invention can prevent the pump casing blank from being deformed too much during casting by using a profiling mold and a pressure device to calibrate the shape of the pump casing blank before processing the pump casing blank, thereby improving the processing accuracy of the pump casing processing and reducing the reserved processing amount of the pump casing during casting, thereby reducing the time required for the pump casing blank to be processed into place, thereby greatly improving the processing efficiency of the pump casing.

[0058] The above are only embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for producing a lubrication pump, characterized in that: The invention relates to a method for processing a pump casing, wherein the method for processing the pump casing comprises the following steps: Model making, making foam models and pouring and riser models; Model clustering: the foam model and the pouring and rising model are combined and bonded together to form a model cluster; For model coating, select special paint, add water and stir it in a paint mixer to obtain the appropriate viscosity, and then apply the paint on the model cluster; Model drying: put the coated model cluster into the drying equipment and dry it at 40-60℃; Melting and pouring, pouring liquid metal into the model cluster, after the liquid metal cools and hardens, the wax model falls off from the surface of the pump casing blank to form the pump casing blank; Before pouring, the amount of molten metal poured is controlled to be M, and the pouring speed is controlled to be V during pouring, M = V*D / F, where: M-the mass of molten metal filled per unit time (kg / s), V-the total volume of the casting and runner (m 3 ), D-metal density (kg / m 3 ), F-casting pouring time (s); v = √2gh, where: v-initial velocity of the molten metal (m / s), g-gravitational acceleration (9.8m / s 2 ), h-the height of the ladle from the pouring head (m); Finishing: finish machining the pump casing blank.

2. The method for producing a lubrication pump according to claim 1, characterized in that: The model making step comprises the following steps: Pre-foaming, adding foam beads into the mold and pre-foaming to expand the beads to a certain size; Maturation: the pre-foamed foam beads are placed in a dry and ventilated silo for a certain period of time, and the aging time is 10-45 hours; Foam molding, fill the pre-foamed and matured foam beads into the cavity of the metal mold, heat it, and must be cooled before demolding to make the model cool down to below the softening temperature. The model will be demolded after hardening and shaping.

3. The method for producing a lubrication pump according to claim 2, characterized in that: The mold is preheated to 100°C, and cooled by spraying water on the back of the mold to quickly cool the mold to 40°C ~ 50°C, and then compressed air is used to blow out the pattern.

4. The method for producing a lubrication pump according to claim 2, characterized in that: After the bubble beads fill the cavity, water vapor is introduced. The water vapor enters from one side of the mold through the air inlet and is discharged from the other side. Under the action of water vapor, the bubble beads soften and expand, fill the gaps between the bubble beads and stick together. After the bubble beads are melted inside, water vapor is blown into the mold from both sides. The water vapor temperature is controlled at 120°C and the pressure is controlled at 0.15MPa.

5. The method for producing a lubrication pump according to claim 1, characterized in that: The finishing step includes the following steps: Blank profiling: buckle the pump casing blank on the profiling die, make the inner end surface of the pump casing blank fit with the reference surface of the profiling die, and use pressure equipment to apply a certain pressure to the pump casing blank; Rough turning of the pump housing, machining the outer end face of the pump body blank and the profile on the outer end face, and machining the circumference of the blank; Semi-finishing machining: remove the pump casing and reinstall it with the outer end face as the reference surface, use the center inner hole as the reference hole, and finish the inner end face and the inner end face profile; CNC milling, taking the outer end face of the pump casing as the reference surface, finishing the inner end face of the pump casing and the sealing ring installation groove, and finishing the profile groove on the inner end face of the pump casing; Finish machining, finish machining all unfinished surfaces on the outer end face of the pump casing, and finish machining the center inner hole of the pump casing.

6. The method for producing a lubrication pump according to claim 1, characterized in that: During the pouring process, in order to prevent the molten metal from cooling, oxidation and splashing, h is controlled at 0.05~0.15m.

7. The method for producing a lubrication pump according to claim 2, characterized in that: The foam beads are expanded polystyrene resin beads.

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