Casting cylinder body preparation method and casting cylinder body

Abstract

The invention discloses a casting cylinder body preparation method. The casting cylinder body preparation method comprises the following steps that 1, the bottom of a plunger hole in a cylinder body is sealed; 2, the copper alloy and the casting cylinder body are sintered; step 3, cooling the cast cylinder body; according to the method, through a segmented cooling mode, casting defects such as shrinkage porosity and shrinkage cavities are avoided, copper-steel bimetal metallurgy diffusion bonding is achieved, it is guaranteed that a copper alloy layer has good mechanical and tribological properties, and therefore the service life of the copper-steel bimetal cylinder body is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of plunger pump cylinder body processing, in particular to a molten cast cylinder body preparation method and a molten cast cylinder body. Background Art

[0002] The cylinder body is a key core part of the plunger pump. Its service life and stability directly affect the service life and quality of the entire plunger pump. When preparing the plunger pump cylinder body, a copper sleeve is often inlaid in the steel base hole of the cylinder body. At present, the copper sleeve is generally inlaid by using a press to directly press the copper sleeve into the plunger hole of the cylinder body at room temperature, so that the copper sleeve and the steel base hole achieve interference fit. This method has high requirements on the process of the cylinder plunger hole before press-fitting, and the processing cost is relatively high. After the copper sleeve is press-fitted, in order to ensure the roundness and straightness of the plunger hole, the copper sleeve needs to be processed again after press-fitting. In addition, during the use of the cylinder body, the copper sleeve of the plunger hole may be scratched, pulled out, and other problems that affect the service life.

[0003] In addition to preparing the cylinder body by inserting a copper sleeve in the plunger hole, there is currently a method of realizing copper-steel bimetallic composite molding in the plunger hole by melt casting. In the process of bimetal smelting, high-temperature smelting is usually required, and cooling technology plays a vital role in this process. Due to the particularity of the cylinder structure, if air cooling is used, typical casting defects such as shrinkage and shrinkage holes will occur during the melting and solidification of the copper alloy, which seriously restricts the performance of the bimetallic material. The direct water cooling and air cooling methods currently used have a fast cooling speed, and the internal stress of the steel matrix and the copper alloy is large during solidification and shrinkage, which leads to cracks at the junction of the copper-steel bimetal, especially the copper-steel junction in the plunger hole. Summary of the invention

[0004] The object of the present invention is to provide a method for preparing a melting and casting cylinder body and a melting and casting cylinder body, so as to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A method for preparing a molten-cast cylinder body comprises the following steps:

[0007] Step 1, seal the bottom of the plunger hole on the cylinder body;

[0008] Step 2, sintering the copper alloy and the molten casting cylinder;

[0009] Step 3, cooling the cylinder body after melting and casting;

[0010] Step 4: Finish the cooled molten cast cylinder.

[0011] As a further solution of the present invention: in the step 1, the plunger hole plug is pressed into the bottom of the plunger hole of the cylinder blank, and then the plug and the edge of the cylinder blank are welded and sealed.

[0012] As a further solution of the present invention: in the step 2, the copper alloy block is placed in a steel matrix copper molten pool and put into a high-temperature furnace for sintering, and the furnace temperature is 1050°C.

[0013] As a further solution of the present invention: the cooling in step 3 adopts air cooling and liquid cooling segmented cooling.

[0014] As a further solution of the present invention: in step 3, cooling comprises the following steps:

[0015] Step 3.1, air cooling: place the molten casting cylinder after being taken out of the furnace in the air and cool it down to the surface temperature of the cylinder being a°C;

[0016] Step 3.2, liquid cooling: placing the casting cylinder after air cooling in step 3.1 into the cooling liquid, the cooling liquid does not completely immerse the casting cylinder, and cooling until the surface temperature of the cylinder is b°C;

[0017] Step 3.3, air cooling: lift the cylinder body after liquid cooling in step 3.2 from the coolant to above the coolant, and cool it in the air until the surface temperature of the cylinder body is c°C;

[0018] Step 3.4, liquid cooling: immerse the cylinder body after air cooling in step 3.3 into the coolant again, the coolant does not completely immerse the casting cylinder body, and cools until the cylinder body partially turns black, and the cooling is completed.

[0019] As a further solution of the present invention: a in step 3.1 is 950-1000, b in step 3.2 is 750-850, and c in step 3.3 is 650-700.

[0020] As a further solution of the present invention: the liquid cooling coolant can be cooling water, quenching liquid or cooling oil.

[0021] As a further solution of the present invention: in step 3.2, the height of the coolant is located at 1 / 3 of the height of the cylinder blank.

[0022] As a further solution of the present invention: in step 3.4, the height of the coolant is located at 1 / 3 of the height of the cylinder blank, and cooling is continued until the blackened part of the cylinder accounts for 2 / 3-3 / 4 of the total blank height, and cooling is completed.

[0023] A melting and casting cylinder body is prepared by the melting and casting cylinder body preparation method according to any one of claims 1 to 9, wherein the melting and casting cylinder body comprises a cylinder body main body, a plurality of plunger holes are opened on the cylinder body, and a copper alloy layer is melt-cast in the plunger holes.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. The present application achieves metallurgical diffusion bonding of copper-steel bimetallic without shrinkage and shrinkage holes by means of segmented cooling, thereby ensuring that the copper alloy layer has good mechanical and tribological properties, thereby improving the service life of the copper-steel bimetallic cylinder.

[0026] 2. After the cylinder blank of the present application is melted and cast out of the furnace, it is slowly cooled in the air for a period of time to reduce the temperature of the cylinder blank and not directly contact the coolant at high temperature, which can avoid the problem of cracking of the copper alloy in the cylinder and the plunger hole due to excessive cooling speed;

[0027] 3. The cylinder blank of the present application is cooled in sections by controlling the temperature, which can reduce the cooling rate of the copper alloy in the plunger hole. At the same time, it is immersed in the coolant for a period of time and then air-cooled, so that the cylinder body produces a similar self-tempering effect, reduces the internal stress caused by the quenching of the copper alloy, and avoids the poor bonding of the copper-steel bimetal in the plunger hole;

[0028] 4. The cylinder body of the present application is designed based on a gradient temperature field. Through a bottom-up directional solidification process, it achieves casting defects such as no shrinkage or shrinkage holes, and bimetallic metallurgical diffusion bonding, ensuring that the copper alloy layer has good mechanical and tribological properties. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. 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.

[0030] In an embodiment of the present invention, a melting and casting cylinder body is provided. The melting and casting cylinder body comprises a cylinder body main body. A plurality of plunger holes are opened on the cylinder body main body. A copper alloy layer is melt-cast in the plunger holes.

[0031] A method for preparing a molten-cast cylinder body comprises the following steps:

[0032] Step 1, seal the bottom of the plunger hole on the cylinder body, specifically, press the plunger hole plug into the bottom of the plunger hole of the cylinder body blank, and then weld and seal the plug and the edge of the cylinder body blank to prevent the copper alloy from leaking during the subsequent melting and casting process;

[0033] Step 2, sintering the copper alloy and the molten casting cylinder, which includes placing the copper alloy block in a steel base copper molten pool, and sintering in a high-temperature furnace, with the furnace temperature being 1050°C;

[0034] Step 3, cooling the cylinder body after melting and casting, using air cooling, liquid cooling and segmented cooling;

[0035] Cooling includes the following steps:

[0036] Step 3.1, air cooling: place the molten casting cylinder after being taken out of the furnace in the air and cool it to a cylinder surface temperature of a°C, where a is 950-1000, that is, slowly cool it in the air to a cylinder surface temperature of 950°C-1000°C;

[0037] Step 3.2, liquid cooling: placing the casting cylinder after air cooling in step 3.1 into the coolant, the coolant does not completely immerse the casting cylinder. In this embodiment, the height of the coolant is located at 1 / 3 of the height of the cylinder blank, and the cylinder surface temperature is cooled to b°C, b is 750-850, that is, the cylinder is cooled in the coolant until the upper surface temperature of the cylinder is 750°C-850°C;

[0038] Step 3.3, air cooling: lift the cylinder body after liquid cooling in step 3.2 from the coolant to above the coolant, and cool it in the air until the surface temperature of the cylinder body is c°C, where c is 650-700°C, that is, slowly cool it in the air again until the upper surface temperature of the cylinder body is 650°C-700°C;

[0039] Step 3.4, liquid cooling: immerse the cylinder body after air cooling in step 3.3 again in the coolant, the coolant does not completely immerse the casting cylinder body, cool until the cylinder body partially turns black, and then the cooling is completed. In this embodiment, the height of the coolant is located at 1 / 3 of the height of the cylinder body blank, and the cooling is continued until the blackened part of the cylinder body accounts for 2 / 3-3 / 4 of the total blank height, and then the cooling is completed;

[0040] Step 4: Finish the cooled cast cylinder body and further process the cylinder body according to the drawing.

[0041] In addition, the coolant of the liquid cooling of the present application can be cooling water, quenching liquid or cooling oil.

[0042] Example 1

[0043] Step 1: Use a hydraulic press to press the plunger hole plug into the bottom of the plunger hole of the cylinder blank, and then weld and seal the plug and the edge of the cylinder blank to prevent copper alloy leakage during the subsequent melting and casting process;

[0044] Step 2: placing the copper alloy block in a steel substrate molten copper pool, and sintering it in a high-temperature furnace through an automated device, with the furnace temperature being 1050°C;

[0045] Step 3: 1. After the cylinder body is cast out of the furnace, it is left to stand and slowly cooled in the air until the surface temperature of the cylinder body reaches 1000°C;

[0046] Step 3.2 After air cooling, immerse the cylinder in the coolant so that the coolant level is 1 / 3 of the height of the cylinder blank. Cool in the coolant until the upper surface temperature of the cylinder is 850℃.

[0047] Step 3.3, lift the cylinder body to the top of the coolant and let it stand, and slowly cool it in the air again until the upper surface temperature of the cylinder body reaches 650°C;

[0048] Step 3.4: After air cooling, immerse the cylinder body in the coolant again, so that the coolant level is 1 / 3 of the height of the cylinder body blank. Continue cooling until the blackened part of the cylinder body occupies 2 / 3 of the total blank height, and the cooling is complete;

[0049] Step 4: Process the cylinder blank according to the drawing.

[0050] Example 2

[0051] Step 1: Use a hydraulic press to press the plunger hole plug into the bottom of the plunger hole of the cylinder blank, and then weld and seal the plug and the edge of the cylinder blank to prevent copper alloy leakage during the subsequent melting and casting process;

[0052] Step 2: placing the copper alloy block in a steel substrate molten copper pool, and sintering it in a high-temperature furnace through an automated device, with the furnace temperature being 1050°C;

[0053] Step 3.1, after the cylinder body is cast out of the furnace, it is left to stand and slowly cooled in the air until the surface temperature of the cylinder body reaches 950°C;

[0054] Step 3.2: After air cooling, immerse the cylinder in the coolant so that the coolant is at 1 / 3 of the height of the cylinder blank. Cool in the coolant until the upper surface temperature of the cylinder is 750℃.

[0055] Step 3.3, lift the cylinder body to the top of the coolant and let it stand, then slowly cool it in the air again until the upper surface temperature of the cylinder body reaches 700°C;

[0056] Step 3.4: After air cooling, immerse the cylinder body in the coolant again, so that the coolant level is at 1 / 3 of the height of the cylinder body blank. Continue cooling until the blackened part of the cylinder body occupies 3 / 4 of the total blank height, and the cooling is complete;

[0057] Step 5: Process the cylinder blank according to the drawing.

[0058] Example 3

[0059] Step 1: Use a hydraulic press to press the plunger hole plug into the bottom of the plunger hole of the cylinder blank, and then weld and seal the plug and the edge of the cylinder blank to prevent copper alloy leakage during the subsequent melting and casting process;

[0060] Step 2: placing the copper alloy block in a steel substrate molten copper pool, and sintering it in a high-temperature furnace through an automated device, with the furnace temperature being 1050°C;

[0061] Step 3.1, after the cylinder body is cast out of the furnace, it is left to stand and slowly cooled in the air until the surface temperature of the cylinder body reaches 980°C;

[0062] Step 3.2: After air cooling, immerse the cylinder in the coolant so that the coolant level is 1 / 3 of the height of the cylinder blank. Cool in the coolant until the upper surface temperature of the cylinder is 800°C.

[0063] Step 3.3, lift the cylinder body to the top of the coolant and let it stand, and slowly cool it in the air again until the upper surface temperature of the cylinder body reaches 680℃;

[0064] Step 3.4: After air cooling, immerse the cylinder body in the coolant again, so that the coolant level is 1 / 3 of the height of the cylinder body blank. Continue cooling until the blackened part of the cylinder body occupies 2 / 3 of the total blank height, and the cooling is complete;

[0065] Step 4: Process the cylinder blank according to the drawing.

[0066] Comparative Example 1

[0067] 1. Use a hydraulic press to press the plunger hole plug into the bottom of the plunger hole of the cylinder blank, and then weld and seal the plug and the edge of the cylinder blank to prevent copper alloy leakage during the subsequent melting and casting process;

[0068] 2. Place the copper alloy block in the steel matrix copper molten pool and sinter it in a high-temperature furnace through an automated device. The furnace temperature is 1050°C.

[0069] 3. After the cylinder body is cast out of the furnace, it is directly immersed in the coolant so that the height of the coolant is 1 / 3 of the height of the cylinder body blank;

[0070] 4. Continue cooling until the surface of the cylinder blank turns completely black, and the cooling is completed;

[0071] 5. Process the cylinder blank according to the drawing.

[0072] Comparative Example 2

[0073] 1. Use a hydraulic press to press the plunger hole plug into the bottom of the plunger hole of the cylinder blank, and then weld and seal the plug and the edge of the cylinder blank to prevent copper alloy leakage during the subsequent melting and casting process;

[0074] 2. Place the copper alloy block in the steel matrix copper molten pool and sinter it in a high-temperature furnace through an automated device. The furnace temperature is 1050°C.

[0075] 3. After the cylinder body is cast out of the furnace, it is placed in the air until the surface of the cylinder body blank turns completely black and the cooling is completed;

[0076] 4. Process the cylinder blank according to the drawing.

[0077] The casting cylinders prepared in Example 1, Example 2, Example 3, Comparative Example 1 and Comparative Example 2 were subjected to wire cutting and tested by color flaw detection. The test positions included the copper-steel junction in the plunger hole and the copper-steel junction at the plunger hole at the bottom of the cylinder body. The test items were whether there were defects, including but not limited to cracks. The test results are shown in the following table:

[0078]

[0079] After testing and comparison, it was found that the copper and steel of the cylinder body prepared by the preparation method of the present application were well bonded, and no bonding defects occurred.

[0080] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

[0081] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A method for preparing a molten casting cylinder body, It is characterized in that The following steps are involved: Step 1, seal the bottom of the plunger hole on the cylinder body; Step 2, sintering the copper alloy and the molten casting cylinder; Step 3, cooling the cylinder body after the casting; Step 4: Finish the cooled molten cast cylinder.

2. A method for preparing a melting and casting cylinder according to claim 1, It is characterized in that In the step 1, the plunger hole plug is pressed into the bottom of the plunger hole of the cylinder blank, and then the plug and the edge of the cylinder blank are welded and sealed.

3. A method for preparing a melting and casting cylinder according to claim 1, It is characterized in that In the step 2, the copper alloy block is placed in a steel substrate copper molten pool and put into a high-temperature furnace for sintering, and the furnace temperature is 1050°C.

4. A method for preparing a melting and casting cylinder according to claim 1, It is characterized in that The cooling in step 3 adopts air cooling and liquid cooling segmented cooling.

5. A method for preparing a melting and casting cylinder according to claim 1, It is characterized in that In step 3, cooling comprises the following steps: Step 3.1, air cooling: place the molten casting cylinder after being taken out of the furnace in the air and cool it down to the surface temperature of the cylinder being a°C; Step 3.2, liquid cooling: placing the casting cylinder after air cooling in step 3.1 into the coolant, the coolant does not completely immerse the casting cylinder, and cooling until the surface temperature of the cylinder is b°C; Step 3.3, air cooling: lift the cylinder body after liquid cooling in step 3.2 from the coolant to above the coolant, and cool it in the air until the surface temperature of the cylinder body is c°C; Step 3.4, liquid cooling: immerse the cylinder body after air cooling in step 3.3 into the coolant again, the coolant does not completely immerse the casting cylinder body, and cools until the cylinder body partially turns black, and the cooling is completed.

6. A method for preparing a melting and casting cylinder according to claim 5, It is characterized in that a in the step 3.1 is 950-1000, b in the step 3.2 is 750-850, and c in the step 3.3 is 650-700.

7. A method for preparing a melting and casting cylinder according to claim 5, It is characterized in that The liquid cooling coolant can be cooling water, quenching liquid or cooling oil.

8. A method for preparing a melting and casting cylinder according to claim 5, It is characterized in that In the step 3.2, the height of the coolant is located at 1 / 3 of the height of the cylinder blank.

9. A method for preparing a melting and casting cylinder according to claim 5, It is characterized in that In the step 3.4, the height of the coolant is located at 1 / 3 of the height of the cylinder blank, and cooling is continued until the blackened part of the cylinder accounts for 2 / 3-3 / 4 of the total blank height, and the cooling is completed.

10. A casting cylinder, It is characterized in that The casting cylinder is prepared by the method for preparing the casting cylinder according to any one of claims 1 to 9, wherein the casting cylinder comprises a cylinder body, a plurality of plunger holes are provided on the cylinder body, and a copper alloy layer is cast in the plunger holes.

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