Heat treatment method for deep blind hole forge piece of integral oil cylinder

Abstract

The invention relates to a heat treatment method for an integral oil cylinder deep blind hole forge piece, which comprises the following steps: firstly, connecting a positioning bracket for limiting the shaking of a liquid injection pipe on the liquid injection pipe, and installing the liquid injection pipe in place when a positioning cap is positioned on the forge piece; then the forge piece is put into cooling liquid to be quenched, meanwhile, a water pump located in the cooling liquid is used for conveying the cooling liquid into the blind hole through a liquid injection pipe, the cooling liquid flowing out of a spiral water outlet drives water flow to rotate spirally, and the cooling liquid flowing out of a liquid outlet flows out of the spiral water outlet after passing through the height of the spiral water outlet; the spiral upwards surges under the driving of cooling liquid flowing out of the spiral water outlet, so that the wall of the blind hole can be uniformly cooled; meanwhile, in the descending process of the forge piece, internal and external liquid levels of the blind hole are kept relatively flush, the blind hole is quenched internally and externally at the same time, stress concentration is avoided, and internal and external quenching effects of the blind hole are the same.

Description

Technical Field

[0001] The invention relates to the field of deep blind hole forging machinery, in particular to the field of deep blind hole forging heat treatment technology, and specifically refers to a heat treatment method for an integral oil cylinder deep blind hole forging. Background Art

[0002] The outer cylinder and the middle cylinder of the column are subject to greater pressure (instantaneous pressure exceeding 90MPa) during the use of the bracket. The outer cylinder and the middle cylinder of the traditional structure column are welded by seamless steel pipes and die forgings, but the tensile strength of the weld is only 600-650Mpa, while the tensile strength of the cylinder material can reach more than 800Mpa. When the bracket is subjected to a large top plate force, there is a risk of cracking because the welds at the bottom of the outer cylinder and the bottom of the middle cylinder are located in the main pressure-bearing area of ​​the column, posing a greater safety and quality hazard.

[0003] The one-piece cylinder product refers to a cylinder with a bottom that is extruded from a forging by a forging process, eliminating the welding process. The cylinder with a bottom is equivalent to a blind hole extending downward on the forging, and the orifice of the blind hole is connected to the top surface of the forging. The depth of the blind hole is deep. When the forging is quenched and cooled, the forging is placed in the coolant from bottom to top. Due to the setting of the blind hole, when the forging is completely immersed in the coolant, the coolant enters the blind hole from the orifice of the blind hole to cool the inside of the blind hole. At this time, the temperature of the coolant rises, and the cooling time and the temperature of the coolant inside and outside the blind hole are different, which causes uneven cooling inside and outside the blind hole, uneven internal and external structures, and stress concentration, thereby affecting the heat treatment of the forging.

[0004] A Chinese patent application with application number CN201610721046.1 discloses a pit furnace heat treatment process for thick-walled blind hole forgings. The blind hole is cooled by injecting liquid into it. However, this solution cannot solve the problems of positioning the injection pipe, shaking of the injection pipe in deep blind holes, and uneven cooling caused by uneven water flow rise in the blind hole. Summary of the invention

[0005] Aiming at the deficiencies of the prior art, the present invention provides a heat treatment method for an integral oil cylinder deep blind hole forging, which is convenient for positioning a liquid injection pipe, restricts the shaking of the liquid injection pipe in the deep blind hole, and makes the coolant in the blind hole rise evenly.

[0006] The present invention is realized by the following technical scheme, a heat treatment method for an integral oil cylinder deep blind hole forging, comprising the following steps: a. Connect a positioning bracket to the injection pipe to limit its shaking. Since the blind hole injection pipe is long, a positioning bracket is used to limit the injection pipe from shaking in the blind hole; b. Then insert the injection pipe and the positioning bracket into the blind hole. When the positioning cap connected to the injection pipe is positioned on the forging, the injection pipe is installed in place; c. Then put the forging into the coolant for quenching. At the same time, use the water pump located in the coolant to transport the coolant to the blind hole through the injection pipe. Part of the coolant enters the blind hole from the liquid outlet at the bottom of the injection pipe, and part of the coolant enters the blind hole from the spiral water outlet. The coolant flowing out of the spiral water outlet drives the water flow to rotate spirally. After passing the height of the spiral water outlet, the coolant flowing out of the liquid outlet spirally surges up under the drive of the coolant flowing out of the spiral water outlet, so that the blind hole wall can be evenly cooled; at the same time, in the process of the forging descending, keep the liquid levels inside and outside the blind hole relatively flush, so that the inside and outside of the blind hole are quenched at the same time, avoid stress concentration, and ensure the same quenching effect inside and outside the blind hole; The positioning bracket includes an inner tube detachably connected to the injection tube, an outer tube fixedly connected to the inner tube, and a plurality of connecting plates connecting the inner tube and the outer tube, wherein the outer diameter of the outer tube is smaller than the inner diameter of the blind hole; The spiral water outlet hole comprises a plurality of water outlets which are opened on the circumferential surface of the water injection pipe and arranged circumferentially, the plurality of water outlets are evenly arranged circumferentially, and the water outlets are all inclined in the same clockwise direction. When the present invention is in use, the positioning cap is arranged to facilitate the position limitation when the injection tube is inserted into the blind hole, and the positioning bracket is arranged to limit the shaking of the injection tube at the bottom of the blind hole, thereby ensuring that the coolant flows out evenly relative to the inner wall of the blind hole; the spiral water outlet is arranged to facilitate driving the coolant to spirally surge, so that the blind hole wall can be evenly cooled.

[0007] Preferably, the angle between the water outlet and the tangent line of the injection pipe at its position is 30°-45°.

[0008] In this preferred solution, the inclination angle of the water outlet is set so that the coolant can rise in a spiral and the coolant in the blind hole can rise evenly.

[0009] Preferably, the upper thread of the inner tube is connected with a plurality of limit bolts arranged along its circumference, and the limit bolts are pressed against the injection tube to fix the inner tube and the injection tube.

[0010] This preferred solution facilitates the fixation of the inner tube to the injection tube by setting the limiting bolt, that is, facilitates the detachable connection of the positioning bracket and the injection tube.

[0011] Preferably, an inclined plate extending inwardly and fixed to the connecting plate is further connected to the inner circumferential surface of the outer tube.

[0012] In this preferred solution, the inclined plate is provided to support the connecting plate, thereby enhancing the connection strength between the connecting plate and the outer tube.

[0013] Preferably, the positioning cap includes an upper positioning ring and a lower positioning ring located below the upper positioning ring and connected to the upper positioning ring, the upper positioning ring is connected to a support frame connected to the injection tube, and the inner circumferential surface of the lower positioning ring is connected to an inner limit block arranged circumferentially and pressed against the circumferential surface of the injection tube.

[0014] When in use, this preferred solution limits the depth of the injection tube inserted into the blind hole through the setting of the upper positioning ring and the support frame; and enhances the connection strength between the positioning cap and the forging through the setting of the lower positioning ring and the inner limit block, as well as the friction between the inner limit block and the forging.

[0015] Preferably, the injection tube passes through the support frame and is threadedly connected to the support frame.

[0016] The arrangement of this preferred solution facilitates the disassembly of the support frame and the injection tube.

[0017] Preferably, the liquid outlet is tapered, and the diameter of the large diameter end of the liquid outlet matches the inner diameter of the liquid injection tube. When this preferred solution is in use, the outlet pressure of the coolant is enhanced by the arrangement of the liquid outlet.

[0018] The beneficial effects of the present invention are as follows: by setting the positioning cap, it is convenient to limit the position of the injection tube when it is inserted into the blind hole; by setting the positioning bracket, the shaking of the injection tube at the bottom of the blind hole is limited, thereby ensuring that the coolant flows out evenly relative to the inner wall of the blind hole; by setting the spiral water outlet, it is convenient to drive the coolant to spiral up, so that the blind hole wall can be cooled evenly; by setting the limit bolt, it is convenient to fix the inner tube to the injection tube, that is, to facilitate the detachable connection of the positioning bracket and the injection tube; by setting the upper positioning ring and the support frame, the depth of the injection tube inserted into the blind hole is limited; by setting the lower positioning ring and the inner limit block, as well as the friction between the inner limit block and the forging, the connection strength between the positioning cap and the forging is enhanced. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the structure of the present invention; Figure 2 for Figure 1 The enlarged schematic diagram at A in the middle; Figure 3 for Figure 1 The enlarged schematic diagram of point B in the middle; Figure 4 for Figure 1 The enlarged schematic diagram at C in the middle; Figure 5 It is a top view schematic diagram of the spiral water outlet; Figure 6 is a top view schematic diagram of the positioning cap; Figure 7 is a top view schematic diagram of a positioning bracket; As shown in the figure: 1. Forging, 2. Blind hole, 3. Liquid injection pipe, 4. Water outlet, 5. Upper positioning ring, 6. Lower positioning ring, 7. Inner limit block, 8. Support frame, 9. Inner tube, 10. Outer tube, 11. Connecting plate, 12. Inclined plate, 13. Liquid outlet, 14. Water pump, 15. Limit bolt. DETAILED DESCRIPTION

[0020] In order to clearly illustrate the technical features of this solution, this solution is described below through a specific implementation method.

[0021] See attached Figure 1-5 The present invention provides a heat treatment method for an integral oil cylinder deep blind hole forging. In this method, a liquid injection pipe 3 is inserted into the blind hole. The liquid injection pipe 3 is connected to a water pump 14 located in the coolant through a pipeline. A positioning cap is threadedly connected to the circumferential surface of the liquid injection pipe 3.

[0022] The positioning cap includes an upper positioning ring 5 and a lower positioning ring 6 located below the upper positioning ring 5 and connected to the upper positioning ring 5. A support frame 8 connected to the injection tube 3 is connected inside the upper positioning ring 5. The top surface of the forging supports the support frame 8. The inner circumferential surface of the lower positioning ring 6 is connected to an inner limit block 7 arranged along the circumferential direction and pressed against the circumferential surface of the injection tube 3. The support frame 8 is in a cross shape. The injection tube 3 passes through the support frame 8 and is threadedly connected to the support frame 8, that is, a thread matching the threaded hole of the support frame 8 is provided on the circumferential surface of the injection tube 3.

[0023] A positioning bracket located below the positioning cap is also provided on the circumferential surface of the injection tube 3, and the positioning bracket includes an inner tube 9 detachably connected to the injection tube 3, an outer tube 10 fixedly connected to the inner tube 9, and a plurality of connecting plates 11 connecting the inner tube 9 and the outer tube 10. The outer diameter of the outer tube 10 is smaller than the inner diameter of the blind hole, and the inner diameter of the inner tube 9 is larger than the inner diameter of the injection tube 3.

[0024] The upper thread of the inner tube 9 is connected with a plurality of limit bolts 15 arranged along its circumference, and the limit bolts 15 are pushed onto the injection tube 3 to fix the inner tube 9 and the injection tube 3. The inner circumferential surface of the outer tube 10 is also connected with an inclined plate 12 extending inwardly and fixed to the connecting plate 11.

[0025] The liquid injection pipe 3 is also provided with a plurality of water outlets 4 located below the positioning bracket. The plurality of water outlets 4 are evenly arranged along the circumference of the liquid injection pipe 3. The water outlets 4 are connected to the inner cavity of the liquid injection pipe 3. The angle between the water outlets 4 and the tangent of the liquid injection pipe 3 at their positions is 30°-45°. The water outlets 4 have the same inclination direction and are all inclined in the same clockwise direction, that is, the water outlets 4 are all inclined clockwise or counterclockwise.

[0026] The liquid outlet 13 of the liquid injection tube 3 is tapered, and the diameter of the large diameter end of the liquid outlet 13 is adapted to the inner diameter of the liquid injection tube 3. A heat treatment method for an integral oil cylinder deep blind hole forging comprises the following steps: a. Connect a positioning bracket to the injection tube 3 to limit its shaking. Since the blind hole injection tube 3 is long, a positioning bracket is used to limit the injection tube 3 from shaking in the blind hole; b. Then insert the injection tube 3 and the positioning bracket into the blind hole. When the positioning cap connected to the injection tube 3 is positioned on the forging, the injection tube 3 is installed in place; c. Then put the forging into the coolant for quenching. At the same time, use the water pump 14 located in the coolant to transport the coolant to the blind hole through the injection pipe 3. Part of the coolant enters the blind hole from the liquid outlet 13 at the bottom of the injection pipe 3, and part of the coolant enters the blind hole from the spiral water outlet. The coolant flowing out of the spiral water outlet drives the water flow to rotate spirally. After passing the height of the spiral water outlet, the coolant flowing out of the liquid outlet 13 spirally rises under the drive of the coolant flowing out of the spiral water outlet 4, so that the blind hole wall can be evenly cooled; at the same time, during the descent of the forging, the liquid levels inside and outside the blind hole are kept relatively flat, so that the inside and outside of the blind hole are quenched at the same time to avoid stress concentration and ensure the same quenching effect inside and outside the blind hole.

[0027] Of course, the above description is not limited to the above examples. Technical features not described in the present invention can be achieved by or by using existing technologies, which will not be described here. The above embodiments and drawings are only used to illustrate the technical scheme of the present invention and are not limitations of the present invention. The present invention is described in detail with reference to the preferred implementation methods. Ordinary technicians in this field should understand that changes, modifications, additions or substitutions made by ordinary technicians in this technical field within the essential scope of the present invention do not depart from the purpose of the present invention, and should also fall within the scope of protection of the claims of the present invention.

Claims

1. A heat treatment method for deep blind hole forgings of integral oil cylinder, characterized in that: The following steps are involved: a. Connecting a positioning bracket to the injection pipe (3) to limit its shaking. Since the blind hole injection pipe (3) is long, the positioning bracket is used to limit the injection pipe (3) from shaking in the blind hole; b. Then, the injection pipe (3) and the positioning bracket are inserted into the blind hole. When the positioning cap connected to the injection pipe (3) is positioned on the forging, the injection pipe (3) is installed in place; c. Then, the forging is placed in the coolant for quenching. At the same time, a water pump (14) located in the coolant is used to transport the coolant to the blind hole through the injection pipe (3). Part of the coolant enters the blind hole from the liquid outlet (13) at the bottom of the injection pipe (3), and part of the coolant enters the blind hole from the spiral water outlet. The coolant flowing out of the spiral water outlet drives the water flow to rotate in a spiral. After the coolant flowing out of the liquid outlet (13) passes through the height of the spiral water outlet, it rises in a spiral driven by the coolant flowing out of the spiral water outlet (4), so that the blind hole wall can be evenly cooled. At the same time, during the process of the forging descending, the liquid levels inside and outside the blind hole are kept relatively flush, so that the inside and outside of the blind hole are quenched at the same time, stress concentration is avoided, and the quenching effect inside and outside the blind hole is ensured to be the same. The positioning bracket comprises an inner tube (9) detachably connected to the injection tube (3), an outer tube (10) fixedly connected to the inner tube (9), and a plurality of connecting plates (11) connecting the inner tube (9) and the outer tube (10); the outer diameter of the outer tube (10) is smaller than the inner diameter of the blind hole; The spiral water outlet hole comprises a plurality of water outlets (4) which are opened on the circumferential surface of the water injection pipe and arranged in the circumferential direction, the plurality of water outlets (4) are evenly arranged in the circumferential direction, and the water outlets (4) are all inclined in the same clockwise direction.

2. The heat treatment method for integral oil cylinder deep blind hole forgings according to claim 1 is characterized in that: The angle between the water outlet (4) and the tangent line of the liquid injection pipe (3) at its location is 30°-45°.

3. The heat treatment method for the integral cylinder deep blind hole forging according to claim 1 is characterized in that: The upper thread of the inner tube (9) is connected to a plurality of limit bolts (15) arranged along its circumference, and the limit bolts (15) are pressed against the injection tube (3) to fix the inner tube (9) and the injection tube (3).

4. The heat treatment method for the integral cylinder deep blind hole forging according to claim 1 is characterized in that: The inner circumferential surface of the outer tube (10) is also connected to an inclined plate (12) extending inwardly and fixed to the connecting plate (11).

5. The heat treatment method for the integral cylinder deep blind hole forging according to claim 1 is characterized in that: The positioning cap comprises an upper positioning ring (5) and a lower positioning ring (6) located below the upper positioning ring (5) and connected to the upper positioning ring (5); a support frame (8) connected to the injection pipe (3) is connected inside the upper positioning ring (5); and inner limit blocks (7) arranged in the circumferential direction and pressed against the circumferential surface of the injection pipe (3) are connected to the inner circumferential surface of the lower positioning ring (6).

6. The heat treatment method for the integral cylinder deep blind hole forging according to claim 5 is characterized in that: The liquid injection tube (3) passes through the support frame (8) and is threadedly connected to the support frame (8).

7. The heat treatment method for the integral oil cylinder deep blind hole forging according to claim 1 is characterized in that: The liquid outlet (13) is tapered, and the diameter of the large-diameter end of the liquid outlet (13) is adapted to the inner diameter of the liquid injection tube (3).

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