CN112264568B

CN112264568B - Forging method of casing jig of air bag of drilling pump for petroleum drilling machine circulation system

Info

Publication number: CN112264568B
Application number: CN202011063519.6A
Authority: CN
Inventors: 康海鹏; 司桂珍; 王金鹏; 李大乔; 唐甲浪; 宋伟
Original assignee: China National Petroleum Corp; Baoji Oilfield Machinery Co Ltd; CNPC National Oil and Gas Drilling Equipment Engineering Technology Research Center Co Ltd
Current assignee: China National Petroleum Corp; Baoji Oilfield Machinery Co Ltd; CNPC National Oil and Gas Drilling Equipment Engineering Technology Research Center Co Ltd
Priority date: 2020-09-30
Filing date: 2020-09-30
Publication date: 2023-05-12
Anticipated expiration: 2040-09-30
Also published as: CN112264568A

Abstract

The invention discloses a die forging method of a drilling pump air bag shell for an oil drilling circulation system, which comprises the following steps: step 1, designing an upper die and a lower die of a die forging die according to the shape and the size of a forging piece; step 2, heating the blank to the initial forging temperature, and performing upsetting, blind hole punching, mandrel drawing and sawing procedures to obtain a blind hole long sleeve-shaped blank; and 3, placing the blind hole long sleeve-shaped blank obtained in the step 2 into the upper die and the lower die obtained in the step 1 for stewing, demoulding the forge piece, performing air cooling, and performing normalizing treatment to obtain the air bag shell. In the forging process, the internal quality of the forging is improved through large deformation in the blank making stage, the blank is in the shape of a blind hole long sleeve blank, the flow direction of metal is limited by means of a tire mold in the final forging process, the appearance of the forging is close to a part, the inner hole of the forging is naturally expanded, the machining allowance of the forging is small, and energy materials are saved. And after the forging is finished, the forging is easy to demolding, and the forging process is simple to operate. The streamline of the forging accords with the shape of the forging, and the mechanical property is excellent.

Description

Forging method of casing jig of air bag of drilling pump for petroleum drilling machine circulation system

Technical Field

The invention belongs to the technical field of petroleum drilling machine equipment manufacturing, and relates to a forging method of a casing die of an air bag of a drilling pump for a petroleum drilling machine circulation system.

Background

In the using process of the drilling pump, because fluid in a drilling pump cylinder is discontinuous or fluid flow and piston movement are asynchronous, the fluid and the end face of the piston are mutually impacted to form a water hammer phenomenon (commonly called a water hammer), pressure fluctuation is caused, abnormal noise is generated in the drilling pump, and the pipeline of the drilling pump is broken when serious. The air bag is an important component part of the drilling pump, and the shell of the air bag is a hollow spherical part, so that the air bag has important effects of stabilizing pressure, reducing fluctuation, increasing water horsepower, reducing lost circulation and the like in the working process of the drilling pump, and is very important to maintain the normal work of the air bag in the well drilling production.

Because the air bag shell is of a spherical special structure with a hollow inside, casting forming or forging-welding forming is adopted at present. Casting products are often scrapped due to the fact that casting defects such as air holes, sand inclusion and cracks are found in the processing process, so that the cost of the products is increased, and the quality cannot be guaranteed. The utilization rate of forging-welding forming materials is high, but equipment investment is large, and the quality of deep V-shaped welding seams is sometimes difficult to ensure.

Disclosure of Invention

The invention aims to provide a forging method of an air bag shell mould of a drilling pump for a petroleum drilling machine circulation system, which solves the problem that the air bag shell cast and formed in the prior art has casting defects such as air holes, sand inclusion, cracks and the like.

The invention adopts the technical scheme that the die forging method of the air bag shell of the drilling pump for the petroleum drilling circulation system comprises the following steps:

step 1, designing an upper die and a lower die of a die forging die according to the shape and the size of a forging piece;

step 2, heating the blank to the initial forging temperature, and performing upsetting, blind hole punching, mandrel drawing and sawing procedures to obtain a blind hole long sleeve-shaped blank;

and 3, placing the blind hole long sleeve-shaped blank obtained in the step 2 into the upper die and the lower die obtained in the step 1 for stewing, demoulding the forge piece, performing air cooling, and performing normalizing treatment to obtain the air bag shell.

In the step 1, the bottom of the upper die is a circular truncated cone type inner cavity, and the top of the upper die is provided with a circular through hole which is communicated with the circular truncated cone type inner cavity; the size of the truncated cone-shaped inner cavity is consistent with that of the upper half part of the forging piece; the bottom of the lower die is a spherical inner cavity, and the top of the lower die is provided with an annular groove for installing a guide sleeve; the spherical inner cavity is consistent with the lower half part of the forging in size; the die forging die is also provided with a gasket, the outer diameter size of the gasket is the same as that of the lower die, and the inner diameter size of the gasket is larger than that of the upper die.

In the step 2, the outer diameter of the long blind hole sleeve-shaped blank 4 is 400mm, the inner diameter is 190mm, the diameter of the small end step is 330mm, the total length is 900mm, the depth of the inner hole is 750mm, and the wall thickness is 105mm.

The initial forging temperature in the step 2 is 1180-1200 ℃, and the heat preservation time is 1.5h.

The step 3 specifically comprises the following steps:

step 3.1, preheating the upper die and the lower die obtained in the step 1;

step 3.2, heating the blind hole long sleeve-shaped blank to the initial forging temperature, preserving heat, and lightly upsetting to remove oxide skin on the surface;

step 3.3, placing the blind hole long sleeve-shaped blank into a lower die for free upsetting to a height of 700mm;

step 3.4, continuously upsetting the blind hole long sleeve-shaped blank by adding a die, and stewing to obtain a forging;

step 3.5, after stewing, the manipulator clamps the lower die to turn over 180 degrees and place the lower die on the gasket, and after pressing down, the forging is automatically demolded from the upper die;

step 3.6, air cooling is carried out after the forgings are taken out of the die, then the forgings are put into a furnace with the temperature of 860 ℃ for heat preservation for 2 hours, and the forgings are taken out of the furnace for air cooling to the room temperature;

the preheating temperature of the upper die and the lower die in the step 3.1 is 200-300 ℃.

The beneficial effects of the invention are as follows:

the air bag shell can be integrally forged, the upper and lower moulding dies limit the metal flow direction in the forging process, and the appearance of the forging is close to that of a part; the forging blank has a simple structure, and the inner hole of the forging blank is expanded to form a natural circular arc hollow; the forging machining allowance is small, raw materials are saved, and the machining efficiency is improved; the forging piece is easy to demold, and the operation is simple and reliable; the metal streamline inside the forging is distributed according to the shape of the part, the subsequent machining is not cut off, and the mechanical property is better.

Drawings

FIG. 1 is a die diagram of a method for forging a casing die of a drill pump air bag for a petroleum drilling machine circulation system according to the present invention;

FIG. 2 is a cross-sectional view of the upper die in the method of forging the casing die of the air bag of the drill pump for the circulation system of the oil rig of the present invention;

FIG. 3 is a cross-sectional view of the lower die of the method for forging the casing of the air bag of the drill pump for the circulation system of the oil rig according to the present invention;

FIG. 4 is a cross-sectional view of a washer in the method of forging a casing form of a casing of a drill pump for a circulation system of an oil rig according to the present invention;

FIG. 5 is a cross-sectional view of a blind hole long sleeve blank in the method of forging the casing die of the air bag of the drill pump for the circulation system of the petroleum drilling machine;

FIG. 6 is a cross-sectional view of a forging piece obtained in the forging method of a casing die of a drill pump air bag for a circulation system of an oil rig according to the present invention;

FIG. 7 is an drawing mandrel of the drill pump air bag housing die forging method for the oil rig circulation system of the present invention;

FIG. 8 is a flow chart of a die forging process in a die forging method of a casing of a drilling pump air bag for an oil drilling circulation system of the present invention;

in the figure, 1, an upper die, 2, a lower die, 3, a gasket, 4, a blind hole long sleeve-shaped blank, 5, a forge piece and 6, an elongation mandrel.

Detailed Description

The invention will be described in detail below with reference to the drawings and the detailed description.

As shown in fig. 1-4, the method for forging the casing of the air bag of the drilling pump for the petroleum drilling circulation system comprises the following steps:

step 1, designing an upper die 1 and a lower die 2 of a die forging die according to the shape and the size of a forging piece 5;

step 2, heating the blank to the initial forging temperature, and performing upsetting, blind hole punching, mandrel drawing and sawing procedures to obtain a blind hole long sleeve-shaped blank 4; the blind hole long sleeve-shaped blank 4 is subjected to upsetting and large deformation process of mandrel drawing in the blank making process, so that the metallurgical defects such as looseness, hollowness and the like in raw materials can be effectively forged, and the quality of the forge piece is improved.

And 3, placing the blind hole long sleeve-shaped blank 4 obtained in the step 2 into the upper die 1 and the lower die 2 obtained in the step 1 for stewing, demoulding the forging 5, performing air cooling, and performing normalizing treatment to obtain the air bag shell.

In the step 1, the bottom of the upper die 1 is a circular truncated cone type inner cavity, and the top of the upper die is provided with a circular through hole which is communicated with the circular truncated cone type inner cavity; the size of the truncated cone-shaped inner cavity is consistent with that of the upper half part of the forging piece 5; the bottom of the lower die 2 is a spherical inner cavity, the top of the lower die is provided with an annular groove provided with a guide sleeve, the guide sleeve plays a role in guiding the upper die 1 in the forging process, so that the central lines of the upper die 1 and the lower die 2 are overlapped, and the blind hole long sleeve-shaped blank 4 is prevented from tilting in the upsetting process; the size of the spherical inner cavity is consistent with that of the lower half part of the forging piece 5; the die forging die is also provided with a gasket 3, the outer diameter size of the gasket 3 is the same as that of the lower die 2, and the inner diameter size is larger than that of the upper die 1, so that the forging piece 5 can be smoothly demolded from the lower die 2.

As shown in fig. 5, in the step 2, the outer diameter of the blind hole long sleeve-shaped blank 4 is 400mm, the inner diameter is 190mm, the diameter of the small end step is 330mm, the total length is 900mm, the depth of the inner hole is 750mm, and the wall thickness is 105mm.

As shown in fig. 8, the step 3 specifically includes the following steps:

step 3.1, preheating an upper die 1 and a lower die 2 obtained in the step 1;

step 3.2, heating the blind hole long sleeve-shaped blank 4 obtained in the step 2 to the initial forging temperature, preserving heat, and lightly upsetting to remove the surface oxide skin;

step 3.3, placing the blind hole long sleeve-shaped blank 4 into a lower die 2, and freely upsetting the blank to a height of 700mm by a pressurizing machine;

step 3.4, adding a die 1 to the blind hole long sleeve-shaped blank 4, guiding the lower part of the upper die 1 into a guide sleeve of the lower die 2, enabling the central lines of the upper die 1, the lower die 2 and the blank to coincide, pressurizing and upsetting the upper die 1 by a press, and stewing to obtain a forging piece 5;

step 3.5, after stewing, the manipulator clamps the lower die 2 to turn over 180 degrees and place the gasket 3 on, and after pressing down, the forging 5 is automatically demolded from the upper die 1;

step 3.6, air cooling is carried out after the forging piece 5 is taken out of the die, then the die is put into a furnace with the temperature of 860 ℃ for heat preservation for 2 hours (normalizing treatment), and the die is taken out of the furnace for air cooling to the room temperature;

the preheating temperature of the upper die 1 and the lower die 2 in the step 3.1 is 200-300 ℃.

The method can forge the forging 5 close to the part in a profiling way, effectively reduces the machining allowance of the forging 5, reserves the complete metal conformal streamline, improves the mechanical property of the forging 5 and prolongs the service life.

The invention also has the following advantages:

1. the die has the advantages of simple structure, easy manufacture, small equipment and tool investment, short forging process, simple and easy operation, the appearance of the forging is close to that of a part, the machining allowance is small, the material waste is reduced, and the production efficiency is improved.

2. The forging deformation is large through the working steps of upsetting, punching, mandrel drawing and the like in the blank making process, the metallurgical defects in the material can be effectively eliminated, the forging quality is good, and the service life is long.

3. The long sleeve-shaped blank with the blind hole is simple in shape, when upsetting in the die, the structural characteristics of the long sleeve-shaped blank with the blind hole are utilized, the inside and the outside of the blank are naturally expanded, the outside of the blank is limited by the die to form the shape of the forging, the inner hole forms the hollow inner cavity of the forging, the required forging pressure is small, the energy is saved, and the forging is easy to form.

4. The forging is formed in the tire mold, the surface quality is good, a metal streamline formed in the forging accords with the shape of the forging, the metal streamline is not cut off during machining, and the mechanical property of the forging is high.

Taking KBD-45 air bag as an example, the air bag shell material is 35CrMo:

1. a braiding process. And (3) formulating a forging diagram according to the part diagram, designing a die forging die, calculating the weight of the forging, the blanking weight and the blanking specification, determining forging initial forging and final forging temperatures, forging times, forging deformation processes, forging equipment, a forging die, a cooling mode after forging and the like, and programming a forging process.

2. And (5) blanking. According to the shape and the size of the forge piece, the weight of the forge piece is 698kg, forging is completed through blank making and final forging for 2 times, and the blanking weight is 733kg and the blanking size is phi 400 multiplied by 739 by considering the crop residue and the fire consumption of the blind hole long sleeve-shaped blank 5.

3. And (5) heating. Heating the blanking to the initial forging temperature of 1180-1200 ℃ according to the heating standard, and preserving the heat for 1.5 hours.

4. The blank is freely upsetted. The billet is freely upset in the vertical direction to a height of about 550 mm.

5. And (5) punching a blind hole. And punching a blind hole in the center of the blank.

6. And drawing the mandrel. And (5) putting the blank obtained in the step (5) on an elongation mandrel (6) to be elongated and pressing a small-head step. The mandrel is continuously rotated according to the key points of the mandrel drawing operation in the drawing process, so that the mandrel is prevented from being seized, the step length of the small end is strictly controlled, and the folding is prevented during upsetting.

7. And (3) sawing off the two ends of the blank obtained in the step (6) on a sawing machine to enable the end surfaces to be flush, and obtaining the blind hole long sleeve-shaped blank (4).

8. And (5) freely upsetting in the die. And (3) reheating the blind hole long sleeve-shaped blank 4, then vertically and lightly upsetting, removing surface oxide skin, placing the blank into the lower die 2, and freely upsetting the press to the height of 700 mm.

9. And (5) stewing in a mold. And (3) sleeving the blank obtained in the step (8) on a die (1), and upsetting and stewing in the die.

10. And (5) demolding. The manipulator holds the lower die 2 to be overturned and placed on the gasket 3, round steel is added for ejection, and the forging piece 5 is automatically demoulded from the round table type cavity of the upper die 1.

11. And cooling after forging. And (5) air cooling and normalizing the forgings after demolding.

Claims

1. The die forging method of the drill pump air bag shell for the petroleum drilling circulation system is characterized by comprising the following steps of:

step 1, designing an upper die (1) and a lower die (2) of a die forging die according to the shape and the size of a forging piece (5); in the step 1, the bottom of the upper die (1) is a circular truncated cone type inner cavity, and the top of the upper die is provided with a circular through hole which is communicated with the circular truncated cone type inner cavity; the size of the inner cavity of the truncated cone is consistent with that of the upper half part of the forging piece (5); the bottom of the lower die (2) is a spherical inner cavity, and the top of the lower die is provided with an annular groove for installing a guide sleeve; the spherical inner cavity is consistent with the lower half part of the forging piece (5) in size; the die forging die is also provided with a gasket (3), the outer diameter size of the gasket (3) is the same as that of the lower die (2), and the inner diameter size is larger than that of the upper die (1);

step 2, heating the blank to the initial forging temperature, and performing upsetting, blind hole punching, mandrel drawing and sawing procedures to obtain a blind hole long sleeve-shaped blank (4); the outer diameter of the blind hole long sleeve-shaped blank (4) in the step 2 is 400mm, the inner diameter is 190mm, the diameter of the small end step is 330mm, the total length is 900mm, the depth of the inner hole is 750mm, and the wall thickness is 105mm;

and 3, placing the blind hole long sleeve-shaped blank (4) obtained in the step 2 into the upper die (1) and the lower die (2) obtained in the step 1 for stewing, demoulding the forge piece (5), performing air cooling, and performing normalizing treatment to obtain the air bag shell.

The initial forging temperature in the step 2 is 1180-1200 ℃, and the heat preservation time is 1.5h;

the step 3 specifically comprises the following steps:

step 3.1, preheating an upper die (1) and a lower die (2) obtained in the step 1;

step 3.2, heating the blind hole long sleeve-shaped blank (4) to the initial forging temperature, preserving heat, and lightly upsetting to remove the oxide skin on the surface;

step 3.3, placing the blind hole long sleeve-shaped blank (4) into a lower die (2) for free upsetting to a height of 700mm;

step 3.4, continuously upsetting the blind hole long sleeve-shaped blank (4) by adding a die (1), and stewing to obtain a forging (5);

after the stewing is completed, the manipulator clamps the lower die (2) to turn over 180 degrees to place the gasket (3), and after the pressing, the forging (5) is automatically demolded from the upper die (1);

and 3.6, air cooling the forgings (5) after demolding, then placing the forgings into a 860 ℃ furnace for heat preservation for 2 hours, discharging the forgings, and air cooling the forgings to room temperature.

2. The method for die forging of a casing of a drilling pump air bag for an oil drilling circulation system according to claim 1, wherein the preheating temperature of the upper die (1) and the lower die (2) in the step 3.1 is 200 to 300 ℃.