Die for oil rail automatic forging and forging method and preform thereof

Abstract

The application discloses a die for oil rail automatic forging, a forging method thereof and a pre-forging piece, and belongs to the technical field of oil rail forging, wherein the die comprises a pre-forging upper die, a pre-forging lower die, an upper ejector rod, an upper elastic piece, a lower ejector rod and a lower elastic piece; the pre-forging upper die and the pre-forging lower die jointly form a pre-forging forming cavity when the pre-forging upper die and the pre-forging lower die are closed; and the edge of the upper die cavity and the edge of the lower die cavity are respectively provided with an outwardly inclined slope. The main oil pipe of the pre-forging piece is circular in cross section and is provided with a slope on both sides of the parting line; the bolt column support angle β and the finish forging angle β1 satisfy β = β1 + 20°; the forging method comprises blank heating, temperature sorting, roll forging, lubricant spraying, pre-forging and finish forging; when pre-forging, the upper die is lifted up while the upper ejector rod is ejected; and the lower ejector rod is delayed for 0.5-1s before being ejected. Through the system cooperation of the die, the pre-forging piece and the forging method, the forging piece folding, edge collapse and other defects are avoided, the automatic continuous production of the oil rail forging is realized, and the finished product quality of the oil rail forging is improved.

Description

Technical Field

[0001] This invention relates to the field of hydraulic rail forging technology, and more particularly to dies for automated hydraulic rail forging, forging methods, and pre-forgings. Background Technology

[0002] The fuel rail is a core component of the engine's fuel supply system, used to store fuel and suppress pressure fluctuations to ensure injection stability. The fuel rail is machined from a forged fuel rail; as a pressure-bearing component, the forging must not have defects such as collapsed edges or folds.

[0003] Currently, hydraulic rail forgings are typically formed using a multi-step hot forging process. For example, patent CN110788263B discloses a manufacturing process for stainless steel hydraulic rail forgings, including seven steps: blanking, heating, billet preparation, pre-forging, final forging, trimming, and post-forging treatment. The main purpose of this patent is to solve the technical problems caused by direct pre-forging of large-diameter billets in traditional processes, such as low material utilization, difficulty in pre-forging, short life of pre-forging dies, and lack of systematic methods for designing the shape of the billet workpiece.

[0004] However, the aforementioned existing technologies still have the following shortcomings: First, the main oil pipe cross-section of existing pre-forged parts is mostly designed to be circular or elliptical. During the pre-forging process, the die opening is prone to collapse deformation after being subjected to large extrusion pressure, forming an inverted conical structure (such as...). Figure 1 As shown in the diagram, this obstructs metal flow, leading to backflow or folding defects in the forging during final forging. Meanwhile, the fuel rail support area is used to fix the fuel rail assembly to the engine, and its structure varies, commonly being block-shaped, plate-shaped, or with reinforcing ribs, to adapt to the installation space and strength requirements of different engines. However, current pre-forging designs do not address specific structural solutions for the support area, easily leading to defects such as edge collapse, skin jamming, or folding in this area during final forging.

[0005] Second, the aforementioned existing technologies do not involve the specific structural design of pre-forging dies.

[0006] Third, with the improvement of forging automation, although existing automated forging solutions have begun to introduce robotic arms for loading and unloading, there is still a problem of instability in the robotic arms' gripping of pre-forged parts, which seriously affects the continuity and stability of automated forging. Summary of the Invention

[0007] This invention addresses at least one of the technical problems existing in the prior art. It provides a mold for automated forging of oil rails, a forging method thereof, and pre-forged parts, which can effectively avoid defects such as folding and edge collapse of forgings, improve the quality of forgings, and realize automated continuous production of oil rail forging.

[0008] The technical solution adopted by the present invention to solve its technical problem is: a mold for automated forging of oil rails, comprising: a pre-forging upper mold, a pre-forging lower mold, an upper ejector rod, an upper elastic element, a lower ejector rod, and a lower elastic element; The upper pre-forging die is movable along the z-axis and positioned above the lower pre-forging die. The upper pre-forging die has an upper mold cavity, and the lower pre-forging die has a lower mold cavity. When the upper and lower pre-forging dies are closed, the upper mold cavity and the lower mold cavity match and together form a pre-forging forming cavity. The opening edge of the upper mold cavity is provided with a first inclined surface, which extends outward in a direction away from the center of the upper mold cavity. The opening edge of the lower mold cavity is provided with a second inclined surface, which extends outward in a direction away from the center of the lower mold cavity. The upper ejector rod is movable along the z-axis and passes through the upper pre-forging die, with the lower end of the upper ejector rod extending into the upper die cavity. The upper elastic element is sleeved on the outside of the upper ejector rod to cause the upper ejector rod to move upward. The lower ejector rod is movable along the z-axis and passes through the lower pre-forging die, with its upper end extending into the lower die cavity. The lower elastic element is sleeved on the outside of the lower ejector rod to cause the lower ejector rod to move downward.

[0009] Furthermore, the angle α1 between the first inclined plane and the xz plane ranges from 20° to 25°, and the angle α2 between the second inclined plane and the xz plane ranges from 20° to 25°.

[0010] Furthermore, the upper mold cavity includes an upper oil pipe main body cavity and two support cavities. The two support cavities are spaced apart and arranged on the same side of the upper oil pipe main body cavity. Each support cavity is provided with a bending protrusion. The bending protrusion includes a first inclined surface and a second inclined surface. The first inclined surface is closer to the upper oil pipe main body cavity than the second inclined surface, and the first inclined surface and the second inclined surface intersect. The second inclined surface forms an angle β with the xy plane. The angle β satisfies the following relationship with the angle β1 formed between the second inclined surface of the corresponding bending protrusion in the upper die of the final forging mold and the xy plane: β = β1 + 20°.

[0011] Furthermore, each end of the upper mold cavity is provided with an upper draft end face, and each upper draft end face extends outward at an angle away from the center of the upper mold cavity. Each end of the lower mold cavity is provided with a lower draft end face, and each lower draft end face extends outward at an angle away from the center of the lower mold cavity. The draft angle of the upper draft end face at the same end relative to the yz plane is not equal to the draft angle of the lower draft end face relative to the yz plane.

[0012] Furthermore, the draft angle of the upper draft end face relative to the yz plane is γ1, and the draft angle of the lower draft end face relative to the yz plane is γ2. γ1 and γ2 satisfy the following condition: γ1 = γ2 + 3°.

[0013] Furthermore, the upper pre-forging die has a first countersunk hole extending along the z-axis, the upper ejector rod is installed in the first countersunk hole, the upper ejector rod has a first upper limit surface, and the two ends of the upper elastic member abut against the first upper limit surface and the countersunk plane of the first countersunk hole, respectively. The pre-forging lower die has a second countersunk hole extending along the z-axis. The lower ejector rod is installed in the second countersunk hole. The lower ejector rod has a first lower limit surface and a second lower limit surface facing away from each other. The two ends of the lower elastic member abut against the first lower limit surface and the countersunk plane of the second countersunk hole, respectively. A lower limit plate is provided at the lower end of the second countersunk hole. The second lower limit surface is operably abut against the lower limit plate.

[0014] Furthermore, a pad, a top plate, and a push rod connector are provided below the pre-forging lower die. The pad has a mounting hole extending along the z-axis. The top plate is slidably installed in the mounting hole. The push rod connector is connected to the upper end of the top plate. The upper end of the push rod connector is opposite to the lower end face of the lower push rod, and there is a gap between the upper end of the push rod connector and the lower end face of the lower push rod. The upper end face of the push rod connector is lower than the upper end face of the pad.

[0015] Furthermore, a groove is provided on the top plate, the groove penetrates the top plate along the z-axis, and the groove is connected to the lower mold cavity through the second countersunk hole.

[0016] A forging method, comprising the following steps: S1. Billet heating: The rod-shaped billet is conveyed and heated simultaneously through an intermediate frequency furnace; S2. Temperature sorting: Receive the rod-shaped billets heated by the medium frequency furnace, and use an automatic temperature sorter to detect the temperature of the heated rod-shaped billets. Qualified rod-shaped billets with temperatures within the preset range are transported to the position waiting to enter the next process, while unqualified rod-shaped billets with temperatures outside the preset range are diverted and eliminated. S3. Roll forging: The qualified bar-shaped billet is transported to the roll forging machine by the first robotic arm for roll forging. S4. Spraying lubricant: While performing S3 roll forging of the billet, lubricant is sprayed onto the mold and the final forging mold for automated forging of oil rails as described above by an automatic spraying device. S5. Pre-forging: After S3 and S4 are completed, the forged billet is fed into the lower mold cavity of the pre-forging die, which is coated with lubricant, by the second robot arm. The upper pre-forging die moves downward along the z-axis and closes with the lower pre-forging die to complete the pre-forging. After the pre-forging is completed, the upper pre-forging die is lifted upward along the z-axis, and at the same time, the upper ejector rod is pushed downward along the z-axis to remove the pre-forged part from the upper mold cavity. Then, the lower ejector rod is pushed upward along the z-axis to remove the pre-forged part from the lower mold cavity. There is a time difference t between the ejection time of the lower ejector rod and the ejection time of the upper ejector rod, and the range of t is 0.5 to 1 second. Then, the force applied to the upper push rod that caused it to push downward is removed, and the upper elastic element applies an upward elastic force to the upper push rod, causing it to move upward and reset; the force applied to the lower push rod that caused it to push upward is removed, and the lower elastic element applies a downward elastic force to the lower push rod, causing it to move downward and reset. S5. Final forging: The pre-forged part, which has been removed from the lower mold cavity of the pre-forging die, is transferred to the final forging die for final forging by a third robotic arm.

[0017] A pre-forged part is forged by the forging method described above, wherein the part comprises a main oil pipe and an oil inlet pipe joint, a pressure testing joint, two bolt column supports, and multiple injector seats disposed on the main oil pipe. The oil inlet pipe joint is integrally connected to one end of the main oil pipe. The two bolt column supports are spaced apart on the same side of the main oil pipe. Each bolt column support has an injector seat at both ends. The pressure testing joint is integrally connected to the other side of the main oil pipe where the bolt column supports are not disposed. The main oil pipe has a circular cross-section and a parting line extending along its axial direction. On the outer wall surfaces of both sides of the parting line, oil pipe bevels are formed. These bevels extend outward from the outer wall surfaces of the main oil pipe in a direction opposite to the center of the cross-section. The angle between the bevels and the xz plane is... The range is 20° to 25°; The end face of the oil inlet pipe joint is divided by the horizontal center plane of the main oil pipe to form a first upper draft surface and a second lower draft surface. The draft angle of the first upper draft surface relative to the vertical direction is... Draft angle relative to the vertical direction of the second lower draft surface They are not equal, and and The following conditions must be met: = +3°; Each bolted column support includes an extension section and a bent section. One end of the extension section is integrally connected to the outer wall of the main oil pipe, and the other end of the extension section extends outward at an angle away from the center of the cross-section of the main oil pipe. The bent section is integrally connected to the other end of the extension section, and the inner wall surface of the bent section forms an angle with the horizontal center plane of the main oil pipe. The inner wall surface of the corresponding bent section on the final forging of the oil rail to be processed forms an angle with the horizontal center plane of the main oil pipe. included angle and included angle The following conditions must be met: = +20°.

[0018] The beneficial effects of this invention are: 1. By setting a first inclined surface and a second inclined surface, the deformation of the die opening after being subjected to extrusion pressure during the pre-forging process expands outward along the inclined direction of the inclined surface, avoiding the formation of a reverse cone defect at the die opening, thereby ensuring smooth metal flow and effectively preventing backflow or folding defects on the surface of the forging.

[0019] 2. In this invention, because the second inclined surface of the bent protrusion inside the bracket cavity satisfies the angular relationship β=β1+20° with the corresponding structure of the final forging die, sufficient final forging material is reserved in the bracket part during the pre-forging stage. This not only avoids the collapse defect caused by insufficient material during final forging, but also ensures the smooth flow of metal during final forging, effectively avoiding folding defects. At the same time, because the draft angles at both ends of the upper mold cavity are not equal to the draft angles at both ends of the lower mold cavity and satisfy γ1=γ2+3°, the pre-forged part can smoothly detach from the mold cavity during the forging process, avoiding the formation of skin or folding defects on the end face of the oil inlet pipe, further improving the quality of final forging.

[0020] 3. This invention, by respectively sleeved with upper and lower elastic elements on the upper and lower ejector rods, enables the upper and lower ejector rods to reset under the elastic force of the upper and lower elastic elements after the ejection operation, ensuring the timeliness and stability of the ejector rod reset, avoiding the jamming phenomenon that occurs when using the self-resetting method, thereby ensuring the demolding effect and surface quality of the forging, and also ensuring the stable operation of the automated production cycle.

[0021] 4. The present invention provides a groove on the top plate, which is connected to the lower mold cavity through the second countersunk hole. This allows the graphite lubricant sprayed during forging to flow into the second countersunk hole through the gap between the lower ejector rod and the second countersunk hole, and then smoothly exit the mold through the groove on the top plate. This effectively avoids the problem of poor top plate reset caused by graphite accumulation, and further improves the continuity and stability of automated production.

[0022] 5. In the forging method of the present invention, after the pre-forging is completed, the upper die is raised upward while the upper ejector rod is pushed downward to make the pre-forged part detach from the upper die. The ejection time of the lower ejector rod is 0.5 to 1 second later than the ejection time of the upper ejector rod. Reasonable timing control ensures that the pre-forged part can smoothly detach from the upper die cavity and the lower die cavity in sequence, avoiding damage or inconsistent falling position of the pre-forged part due to improper ejection timing. It also ensures that the third robot can stably grasp the pre-forged part, thereby significantly improving the continuity and stability of automated forging. Attached Figure Description

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0024] Figure 1 This is a schematic diagram of defects at the mold opening in existing technology.

[0025] Figure 2 This is a schematic diagram of the structure of a mold for automated forging of oil rails according to the present invention.

[0026] Figure 3 yes Figure 2 A bottom view.

[0027] Figure 4 yes Figure 3 Schematic diagram of the cross-sectional structure of AA.

[0028] Figure 5 yes Figure 3 Schematic diagram of the cross-sectional structure of BB.

[0029] Figure 6 yes Figure 5 A magnified schematic diagram of the local structure at point C.

[0030] Figure 7 This is a schematic diagram of the structure of the pre-forging upper die of the present invention.

[0031] Figure 8 This is a schematic diagram of the pre-forging lower die of the present invention.

[0032] Figure 9 This is a cross-sectional view of the pre-forged forming cavity of the present invention.

[0033] Figure 10 This is a cross-sectional view of the pre-forged forming cavity of the present invention from another perspective.

[0034] Figure 11 This is a schematic diagram of the structure of the pad of the present invention.

[0035] Figure 12 This is a schematic diagram of the top plate of the present invention.

[0036] Figure 13 This is a schematic diagram of the structure of the lower limit plate of the present invention.

[0037] Figure 14 This is a schematic diagram of the upper push rod of the present invention.

[0038] Figure 15 This is a schematic diagram of the lower push rod of the present invention.

[0039] Figure 16 This is a deformation trend diagram of the upper or lower model cavity opening of the present invention.

[0040] Figure 17 This is a schematic diagram of the structure of a pre-forged part according to the present invention.

[0041] Figure 18 yes Figure 17 The main view.

[0042] Figure 19 yes Figure 18 Schematic diagram of the cross-sectional shape of the main oil pipe at the FF section.

[0043] Figure 20 yes Figure 18 Schematic diagram of the cross-sectional shape of the bolt column support at point GG.

[0044] Figure 21 This is a schematic diagram of the metal streamlines of the cross-section of the bolt column bracket of the present invention.

[0045] Figure 22 This is an example diagram of the metal streamline of the cross-section of the bolt column bracket according to an embodiment of the present invention.

[0046] Figure 23 yes Figure 18 A schematic diagram of the partial structure of the cross-section at point HH.

[0047] Figure 24 yes Figure 23 A magnified schematic diagram of the structure at point I in the middle.

[0048] Figure 25 This is a schematic diagram of the metal streamlines of the cross-section of the oil inlet pipe connector of the present invention.

[0049] Figure 26 This is an example diagram of the metal streamlines of the oil inlet pipe joint cross-section according to an embodiment of the present invention.

[0050] Figure 27 This is a schematic flowchart of the forging method of the present invention.

[0051] In the figure: 1. Pre-forging upper die; 101. Upper die cavity; 1011. Upper oil pipe main body cavity; 1012. Support cavity; 1013. Bending protrusion; 10131. First inclined surface; 10132. Second inclined surface; 1014. Upper draft die end face; 102. First countersunk hole; 103. Arc chamfer; 104. First inclined surface; 2. Pre-forging lower die; 201. Lower die cavity; 2011. Lower draft die end face; 202. Second countersunk hole; 203. Second inclined surface; 3. Upper push rod; 301. First upper limit surface; 302. Upper cylindrical rod section; 303. Upper annular section; 4. Upper elastic element; 5. Lower push rod; 501. First lower limit surface; 502. Second lower limit surface; 503. Lower cylindrical rod section; 504. Lower annular section; 6. Lower elastic element; 7. Lower limit plate; 701. Through hole; 702. Locking countersunk hole; 8. Top plate; 801. Groove; 9. Pad; 901. Mounting hole; 10. Gap; 11. Top rod connection; 12. Medium frequency furnace; 13. First robotic arm; 14. Second robotic arm; 15. Third robotic arm; 16. Final forging die; 17. Main oil pipe; 1701. Oil pipe inclined surface; 1702. Upper arc segment; 1703. Lower arc segment; 1704. Upper inclined line segment; 1705. Lower inclined line segment; 1706. First draft surface; 1707. Second draft surface; 18. Oil inlet pipe connector; 1801. First upper draft surface; 1802. Second lower draft surface; 19. Bolted column bracket; 1901. Extension section; 1902. Bent section; 20. Pressure test connector; 21. Injector housing; 22. Automatic temperature sorting device; 23. Roll forging machine. Detailed Implementation

[0052] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the invention, and therefore only show the components relevant to the invention.

[0053] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, features defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0054] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0055] like Figure 1-16 The image shows a preferred embodiment of the present invention for an automated forging die for oil rails, comprising: a pre-forging upper die 1, a pre-forging lower die 2, an upper ejector rod 3, an upper elastic element 4, a lower ejector rod 5, and a lower elastic element 6; in the actual forging process, the pre-forging lower die 2 is fixedly set, and the pre-forging upper die 1 is set on the moving end of the drive mechanism, for example, the pre-forging upper die 1 is driven up and down by a hydraulic press.

[0056] The upper pre-forging die 1 is movably positioned above the lower pre-forging die 2 along the z-axis. The upper pre-forging die 1 has an upper mold cavity 101, and the lower pre-forging die 2 has a lower mold cavity 201. When the upper pre-forging die 1 and the lower pre-forging die 2 are closed, the upper mold cavity 101 and the lower mold cavity 201 match and together form a pre-forging forming cavity. The opening edge of the upper mold cavity 101 is provided with a first inclined surface 104, which extends outwardly in a direction away from the center of the upper mold cavity 101. The opening edge of the lower mold cavity 201 is provided with a second inclined surface 203, which extends outwardly in a direction away from the center of the lower mold cavity 201. Thus, as Figure 16 As shown, during the pre-forging process, the deformation of the opening of the upper mold cavity 101 or the opening of the lower mold cavity 201 after being subjected to extrusion pressure expands outward along the inclined direction of the slope, rather than as... Figure 1In this way, the inverted cone defect at the mold opening is avoided, thus ensuring smooth metal flow and effectively preventing backflow or folding defects on the surface of the forging. The upper ejector rod 3 is movable along the z-axis and passes through the upper pre-forging die 1, with its lower end extending into the upper die cavity 101. The upper elastic element 4 is sleeved on the outside of the upper ejector rod 3 to promote its upward movement and to apply an upward elastic force to it. In other words, after the upper ejector rod 3 moves downward to eject the pre-forging part and detaches it from the upper die cavity 101, it needs to return to its original position. Therefore, the upper elastic element 4 applies an upward elastic force to the upper ejector rod 3 to ensure its timely return to its original position.

[0057] The lower ejector rod 5 is movable along the z-axis and passes through the lower pre-forging die 2, with the upper end of the lower ejector rod 5 extending into the lower die cavity 201. The lower elastic element 6 is sleeved on the outside of the lower ejector rod 5 to promote the lower ejector rod 5 to move downward. In other words, after the lower ejector rod 5 moves upward and lifts the pre-forging part, causing the pre-forging part to detach from the lower die cavity 201, the lower ejector rod 5 needs to be reset downward. Therefore, the lower elastic element 6 applies a downward elastic force to the lower ejector rod 5 to ensure that the lower ejector rod 5 is reset in time.

[0058] Specifically, the upper push rod 3 and the lower push rod 5 are respectively installed on the moving end of a drive device capable of linear motion, such as a drive cylinder or an electric push rod, so as to push the forged pre-forged part out of the upper mold cavity 101 and the lower mold cavity 201.

[0059] In a preferred embodiment, the angle α1 between the first inclined plane 104 and the xz plane ranges from 20° to 25°, and the angle α2 between the second inclined plane 203 and the xz plane ranges from 20° to 25°.

[0060] Specifically, the values ​​of α1 and α2 directly affect the pre-forging and final forging effects: the smaller the values ​​of α1 and α2, the closer the inclined plane is to the xz plane, and the weaker the tendency of the die orifice deformation to expand outward along the inclined direction during pre-forging, but there is still a risk of developing a reverse cone; the larger the values ​​of α1 and α2, the more material accumulates at the die orifice during pre-forging, and the more this material flows through the orifice of the final forging die 16 to the flash storage area during final forging, thus accelerating the wear of the final forging die 16 and shortening the die life. Therefore, limiting α1 and α2 to 20°~25° can meet the dual requirements of avoiding reverse cone defects and controlling die wear.

[0061] In other words, the first inclined surface 104 and the second inclined surface 203 are configured such that during the pre-forging process, the deformation of the die opening under the action of extrusion pressure extends along the inclined direction of the inclined surface. Therefore, by pre-setting a reverse compensation amount in the parts of the die that are prone to wear and deformation, even if the die opening is worn and deformed during normal production, its surface will not be concave, thereby avoiding the formation of a tapered defect at the die opening, ensuring smooth metal flow, and effectively preventing the forging surface from folding.

[0062] In a preferred embodiment, the upper mold cavity 101 includes an upper oil pipe main body cavity 1011 and two support cavities 1012. The two support cavities 1012 are spaced apart on the same side of the upper oil pipe main body cavity 1011. Each support cavity 1012 is provided with a bending protrusion 1013. The bending protrusion 1013 includes a first inclined surface 10131 and a second inclined surface 10132. The first inclined surface 10131 is closer to the upper oil pipe main body cavity 1011 than the second inclined surface 10132, and the first inclined surface 10131 and the second inclined surface 10132 are intersected. The second inclined surface 10132 forms an angle β with the xy plane. The angle β satisfies the following relationship with the angle β1 formed between the second inclined surface 10132 of the corresponding bending protrusion 1013 in the final forging upper die of the final forging die 16: β = β1 + 20°.

[0063] Specifically, the value of β directly affects the pre-forging and final forging effects: the smaller the value of β, the greater the resistance to metal flow during pre-forging, and the more prone it is to folding defects during final forging; the larger the value of β, the less material flows into the distal part of the support cavity 1012, and the less material can be completely filled into the support cavity 1012 during final forging, which can easily lead to edge collapse defects. Therefore, it is possible to provide sufficient material supply for final forging to avoid edge collapse, and to ensure smooth metal flow during final forging to avoid folding.

[0064] In a preferred embodiment, the upper mold cavity 101 is provided with upper draft end faces 1014 at both ends, and each upper draft end face 1014 extends outward in a direction away from the center of the upper mold cavity 101. The lower mold cavity 201 is provided with lower draft end faces 2011 at both ends, and each lower draft end face 2011 extends outward in a direction away from the center of the lower mold cavity 201. The draft angle of the upper draft end face 1014 at the same end relative to the yz plane is not equal to the draft angle of the lower draft end face 2011 relative to the yz plane.

[0065] In a preferred embodiment, the draft angle of the upper draft die face 1014 relative to the yz plane is γ1, and the draft angle of the lower draft die face 2011 relative to the yz plane is γ2, wherein γ1 = γ2 + 3°. This structure allows the pre-forged part to smoothly detach from the mold cavity, avoiding defects such as skin jamming and folding at both ends of the pre-forged part, thus further improving the final forging quality.

[0066] In a preferred embodiment, the upper push rod 3 includes an upper cylindrical rod portion 302 and an upper annular portion 303. The upper annular portion 303 is integrally sleeved on the outside of the upper cylindrical rod portion 302, and the lower end face of the upper annular portion 303 forms a first upper limit surface 301. A first countersunk hole 102 is opened in the pre-forging upper die 1, which extends through the z-axis direction. The upper push rod 3 is installed in the first countersunk hole 102, and the two ends of the upper elastic member 4 abut against the countersunk plane of the first upper limit surface 301 and the first countersunk hole 102, respectively.

[0067] In a preferred embodiment, the lower push rod 5 includes a lower cylindrical rod portion 503 and a lower annular portion 504. The lower annular portion 504 is integrally fitted onto the outside of the lower cylindrical rod portion 503. The upper end face of the lower annular portion 504 forms a first lower limiting surface 501, and the lower end face of the lower annular portion 504 forms a second upper limiting surface. A second countersunk hole 202 is provided in the pre-forging lower die 2, which extends along the z-axis. The lower push rod 5 is installed in the second countersunk hole 202. The two ends of the lower elastic member 6 abut against the countersunk planes of the first lower limiting surface 501 and the second countersunk hole 202, respectively.

[0068] Specifically, both the upper elastic element 4 and the lower elastic element 6 are springs. The lower elastic element 6 is in a pre-compressed state during installation, with a pre-compression of 3mm to 5mm. The pre-compression of the spring refers to the difference between the length of the spring in its free state and its length in its compressed state when installed in the mold. In other words, when the upward ejection force applied to the lower end of the lower ejector rod 5 is removed, the lower elastic element 6, under the action of its own elastic force, drives the lower ejector rod 5 to move downward to complete the reset.

[0069] More specifically, if the preload is less than 3mm, the initial elastic force of the spring is insufficient, and the lower ejector rod 5 may still not be able to fully return to its original position. If the preload is greater than 5mm, the initial elastic force of the spring is too large, and the lower ejector rod 5 needs to overcome a large spring reaction force when ejecting the forging, which can easily lead to increased ejection resistance and affect the demolding effect. Therefore, setting the preload to 3mm to 5mm can ensure that the lower ejector rod 5 returns to its original position reliably without generating excessive resistance to the ejection action.

[0070] In a preferred embodiment, a lower limiting plate 7 is provided at the lower end of the pre-forging lower die 2. The lower limiting plate 7 is installed at the lower end opening of the second countersunk hole 202. A through hole 701 is provided on the lower limiting plate 7 for the lower end of the lower push rod 5 to pass through. The second lower limiting surface 502 is operablely abutting against the lower limiting plate 7.

[0071] In other words, after the pushing force applied to the lower push rod 5 is canceled, the lower elastic member 6 drives the lower push rod 5 to move downward under the action of its own elastic force. When the second lower limit surface 502 abuts against the upper surface of the lower limit plate 7, it means that the lower push rod 5 has been reset to the correct position. The lower limit plate 7 plays the role of limiting the downward movement of the lower push rod 5.

[0072] In a preferred embodiment, the lower limit plate 7 is provided with a locking countersunk hole 702 extending along the z-axis. By installing screws into the locking countersunk hole 702, the lower limit plate 7 is fixed on the pre-forging lower die 2.

[0073] In a preferred embodiment, a pad 9, a top plate 8, and a push rod connector 11 are provided below the pre-forging lower die 2. The pad 9 has a mounting hole 901 extending along the z-axis. The top plate 8 is slidably installed in the mounting hole 901. The push rod connector 11 is connected to the upper end of the top plate 8. The upper end of the push rod connector 11 is opposite to the lower end face of the lower push rod 5, and there is a gap 10 between the upper end of the push rod connector 11 and the lower end face of the lower push rod 5. The upper end face of the push rod connector 11 is lower than the upper end face of the pad 9, which facilitates the assembly and disassembly of the die.

[0074] In other words, the existence of this gap 10 ensures that, in the non-ejected state, the push rod connecting rod 11 will not interfere with the lower push rod 5, and the lower push rod 5 will remain in the reset state only by the spring force. When the top plate 8 moves upward, it drives the push rod connecting rod 11 to move upward until the upper end of the push rod connecting rod 11 abuts against the lower end face of the lower push rod 5, and pushes the lower push rod 5 upward.

[0075] In a preferred embodiment, a groove 801 is provided on the top plate 8. The groove 801 penetrates the top plate 8 along the z-axis and is connected to the lower mold cavity 201 through the second countersunk hole 202. This allows the graphite lubricant sprayed during forging to flow into the mounting hole 901 through the gap 10 between the lower ejector rod 5 and the second countersunk hole 202, and then smoothly exit the mold through the groove 801 on the top plate 8. This avoids the top plate 8 from being unable to move smoothly due to graphite accumulation, thereby avoiding the lower ejector rod 5 from not resetting smoothly.

[0076] In a preferred embodiment, two grooves 801 are provided, and the two grooves 801 are respectively provided on the opposite side walls of the top plate 8. Each groove 801 is arc-shaped and recessed from its side wall toward the center of the top plate 8.

[0077] In a preferred embodiment, the lower end of the first countersunk hole 102 and the upper end of the second countersunk hole 202 are respectively provided with arc-shaped chamfers 103, which reduces the friction and wear between the ejector pin and the hole during the reciprocating motion and extends the service life of the mold.

[0078] In a preferred embodiment, there are multiple upper ejector rods 3 and upper elastic elements 4, as well as multiple lower ejector rods 5 and lower elastic elements 6. Specifically, the present invention employs a mold for automated forging of hydraulic rails. Due to the complex structure of the pre-forged hydraulic rail, the ejector rods cannot be too concentrated. It is necessary to ensure that the pre-forged part does not tilt after ejection so that the robot arm can accurately grip it each time. Therefore, multiple upper ejector rods 3 are distributed on both sides of the middle area of ​​the pre-forged part, and multiple lower ejector rods 5 are distributed on both sides of the two end areas of the pre-forged part.

[0079] In a preferred embodiment, the die for automated forging of hydraulic rails of the present invention, together with the final forging die and the automatic spraying device, constitutes a die forging machine. The final forging die and the automatic spraying device both employ existing technologies known in the art; they only need to be able to achieve the functions of final forging and spraying graphite lubricant into the die cavity, respectively. Their specific structures will not be described in detail here, and those skilled in the art can implement them based on ordinary technical knowledge.

[0080] like Figure 27 As shown, a forging method includes the following steps: S1. Billet heating: The rod-shaped billet is conveyed and heated simultaneously through the medium-frequency furnace 12.

[0081] S2. Temperature sorting: Receive the rod-shaped billets heated by the medium-frequency furnace 12, and use the automatic temperature sorter 22 to detect the temperature of the heated rod-shaped billets. Transport qualified rod-shaped billets with temperatures within the preset range to the position waiting to enter the next process, and divert and remove unqualified rod-shaped billets with temperatures outside the preset range.

[0082] S3, Roll forging: The qualified bar-shaped billet is transported to the roll forging machine 23 by the first robot arm 13 for roll forging.

[0083] S4. Applying lubricant: While performing the S3 roll forging of the billet, an automatic spraying device is used to spray lubricant onto the mold for automated forging of the oil rail as described in any of the above embodiments and the final forging mold 16; specifically, the lubricant is graphite lubricant.

[0084] S5. Pre-forging: After S3 and S4 are completed, the forged billet is fed into the lower mold cavity 201 of the pre-forging lower die 2, which is coated with lubricant, by the second robot arm 14. The pre-forging upper die 1 moves downward along the z-axis and closes with the pre-forging lower die 2 to complete the pre-forging. After the pre-forging is completed, the pre-forging upper die 1 is lifted upward along the z-axis, and at the same time, the upper ejector rod 3 is pushed downward along the z-axis to make the pre-forged part separate from the upper mold cavity 101. Then the lower ejector rod 5 is pushed upward along the z-axis to make the pre-forged part separate from the lower mold cavity 201. There is a time difference t between the ejection time of the lower ejector rod 5 and the ejection time of the upper ejector rod 3, and the range of t is 0.5 to 1 second.

[0085] In other words, the ejection time of the upper ejector rod 3 should be synchronized with the lifting time of the pre-forging upper die 1. If the ejection time of the upper ejector rod 3 is too early, the pre-forging upper die 1 has not yet been lifted, which will cause the pre-forged part to be unable to smoothly detach from the upper die cavity 101. If the ejection time of the upper ejector rod 3 is too late, the pre-forging upper die 1 will move upward with the pre-forged part to a certain height. When the upper ejector rod 3 ejects again at this time, the pre-forged part will fall freely from the height to the pre-forging lower die 2, which will damage the pre-forged part and cause folding defects during the final forging. At the same time, the free fall of the pre-forged part from the height will cause the position of the pre-forged part to be unpredictable, and the third robot arm 15 will not be able to accurately grasp the pre-forged part, affecting the continuity of automated production.

[0086] The ejection time of the lower ejector rod 5 should be 0.5 to 1 second later than the ejection time of the upper ejector rod 3. If the ejection time of the lower ejector rod 5 is earlier than the ejection time of the upper ejector rod 3, the pre-forging part cannot be separated from the lower pre-forging die 2, which will cause the third robot arm 15 to be unable to stably grasp the pre-forging part, affecting the continuity of automated production.

[0087] Then, the pushing force applied to the upper push rod 3, which causes the upper push rod 3 to push downward, is removed. The upper elastic element 4 applies an upward elastic force to the upper push rod 3, causing the upper push rod 3 to move upward and reset. The force applied to the lower push rod 5, which causes the lower push rod 5 to push upward, is removed. That is, the top plate 8 drives the push rod connecting rod 11 to move downward along the z-axis. Subsequently, the upper end face of the push rod connecting rod 11 separates from the lower end face of the lower push rod 5. The lower elastic element 6 applies a downward elastic force to the lower push rod 5, causing the lower push rod 5 to move downward and reset.

[0088] S5. Final forging: The pre-forging part that has been removed from the lower mold cavity 201 of the pre-forging lower mold 2 is transferred to the final forging mold 16 for final forging by the third robot arm 15.

[0089] like Figure 17-26 As shown, a pre-forged part is forged using the mold for automated forging of hydraulic rails according to any of the above embodiments and forged by the forging method described above. The part includes a main oil pipe 17 and an oil inlet pipe connector 18, a pressure testing connector 20, two bolt column supports 19, and multiple injector seats 21 disposed on the main oil pipe 17. The oil inlet pipe connector 18 is integrally connected to one end of the main oil pipe 17. The two bolt column supports 19 are spaced apart on the same side of the main oil pipe 17. Each bolt column support 19 has an injector seat 21 at both ends. The pressure testing connector 20 is integrally connected to the other side of the main oil pipe 17 where the bolt column supports 19 are not disposed.

[0090] In a preferred embodiment, the main oil pipe 17 has a circular cross-section and a parting line extending along its axial direction. Oil pipe bevels 1701 are formed on the outer wall surfaces on both sides of the parting line. The oil pipe bevels 1701 extend outward from the outer wall surface of the main oil pipe 17 in a direction opposite to the center of the cross-section of the main oil pipe 17. The angle between the oil pipe bevels 1701 and the xz plane is... The range is 20° to 25°. In other words, the inclined surface 1701 of the oil pipe is forged by the first inclined surface 104 at the opening of the upper mold cavity 101 and the second inclined surface 203 at the opening of the lower mold cavity 201 during the pre-forging process.

[0091] Specifically, α1, α2 The value is 24°.

[0092] Specifically, the cross-sectional outline of the main oil pipe 17 includes an upper arc segment 1702, a lower arc segment 1703, an upper inclined line segment 1704, and a lower inclined line segment 1705. The upper arc segment 1702 and the lower arc segment 1703 are arranged vertically opposite each other. There are two upper inclined line segments 1704, which are respectively connected to the left and right ends of the upper arc segment 1702 and extend downwards at an incline. There are two lower inclined line segments 1705, which are respectively connected to the left and right ends of the lower arc segment 1703 and extend upwards at an incline. The upper inclined line segments 1704 and the lower inclined line segments 1705 on the same side connect at the parting line, and each upper inclined line segment 1704 and each lower inclined line segment 1705 is symmetrically arranged with respect to the parting line. The angle between each upper inclined line segment 1704 and each lower inclined line segment 1705 and the vertical direction is 1705. .

[0093] Specifically, the upper arc segment 1702 and the lower arc segment 1703 can be part of a circle or an ellipse. This arc structure ensures the roundness of the main cross-section of the main oil pipe 17 and meets the strength requirements of the oil rail. The upper inclined segment 1704 and the lower inclined segment 1705 are connected at the parting line and are symmetrically arranged, so that the cross-section of the main oil pipe 17 forms a contour shape that smoothly transitions from an arc to an inclined surface. Thus, during the pre-forging process, the force at the die opening can be symmetrically transmitted outward along the upper inclined segment 1704 and the lower inclined segment 1705, so that the deformation direction of the die opening is effectively guided to the inclination direction of the inclined surface.

[0094] In a preferred embodiment, the end face of the oil inlet pipe connector 18 is divided by the horizontal center plane of the main oil pipe 17 to form a first upper draft surface 1801 and a second lower draft surface 1802, and the draft angle of the first upper draft surface 1801 relative to the yz plane is... Draft angle of the second lower draft surface 1802 relative to the yz plane They are not equal, and and The following conditions must be met: = +3°; In other words, the first upper draft die surface 1801 is forged from the upper draft die end face 1014 at one end of the upper mold cavity 101, and the second lower draft die surface 1802 is forged from the lower draft die end face 2011 at one end of the lower mold cavity 201. This allows the pre-forged part to smoothly exit the mold cavity, avoiding defects such as skin jamming and folding at the oil inlet pipe end face, further improving the final forging quality. For details, please refer to... Figure 25 , Figure 26 As shown, the cross-sectional streamlines are clear, without interruption or turbulence, and without folding defects.

[0095] Specifically, γ2 and If all values ​​are 5°, then γ1 = =8°.

[0096] In a preferred embodiment, the end face of the other end of the main oil pipe 17 is divided by the horizontal center plane of the main oil pipe 17 to form a first draft surface 1706 and a second draft surface 1707. The draft angle of the first draft surface 1706 relative to the yz plane is not equal to the draft angle of the second draft surface 1707 relative to the yz plane. In other words, the first draft surface 1706 is forged from the upper draft end face 1014 at the other end of the upper mold cavity 101, and the second draft surface 1707 is forged from the lower draft end face 2011 at the other end of the lower mold cavity 201.

[0097] In a preferred embodiment, each bolt column bracket 19 includes an extension section 1901 and a bent section 1902. One end of the extension section 1901 is integrally connected to the outer wall of the main oil pipe 17, and the other end of the extension section 1901 extends outward at an angle away from the center of the cross-section of the main oil pipe 17. The bent section 1902 is integrally connected to the other end of the extension section 1901. An angle is formed between the inner wall surface of the bent section 1902 and the horizontal center surface of the main oil pipe 17 (the horizontal center surface of the main oil pipe 17 is the parting surface where the parting line of the main oil pipe 17 is located). The inner wall surface of the corresponding bent section 1902 on the oil rail final forging to be processed forms an angle with the horizontal center plane of the main oil pipe 17. included angle and included angle The following conditions must be met: = +20°. In other words, the inner wall surface of the bent section 1902 is forged from the second inclined surface 10132 of the bent protrusion 1013 in the support cavity 1012. For details, please refer to... Figure 21 , Figure 22 As shown, the cross-sectional streamlines are clear, without interruption or turbulence, and without folding defects.

[0098] Specifically, and If all values ​​are 110°, then β = =130°.

[0099] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A die for automated forging of hydraulic rails, characterized in that, include: Pre-forging upper die (1), pre-forging lower die (2), upper ejector rod (3), upper elastic element (4), lower ejector rod (5) and lower elastic element (6); The pre-forging upper die (1) is movable along the z-axis and positioned above the pre-forging lower die (2). The pre-forging upper die (1) is provided with an upper mold cavity (101), and the pre-forging lower die (2) is provided with a lower mold cavity (201). When the pre-forging upper die (1) and the pre-forging lower die (2) are closed, the upper mold cavity (101) and the lower mold cavity (201) match and together form a pre-forging forming cavity. The opening edge of the upper mold cavity (101) is provided with a first inclined surface (104). The first inclined surface (104) extends outward in a direction away from the center of the upper mold cavity (101). The opening edge of the lower mold cavity (201) is provided with a second inclined surface (203). The second inclined surface (203) extends outward in a direction away from the center of the lower mold cavity (201). The upper push rod (3) is movable along the z-axis and passes through the pre-forging upper die (1), and the lower end of the upper push rod (3) extends into the upper die cavity (101). The upper elastic element (4) is sleeved on the outside of the upper push rod (3) to cause the upper push rod (3) to move upward. The lower push rod (5) is movable along the z-axis and passes through the pre-forging lower die (2), and the upper end of the lower push rod (5) extends into the lower die cavity (201). The lower elastic member (6) is sleeved on the outside of the lower push rod (5) to cause the lower push rod (5) to move downward.

2. The die for automated forging of hydraulic rails according to claim 1, characterized in that, The angle α1 between the first inclined plane (104) and the xz plane is in the range of 20° to 25°, and the angle α2 between the second inclined plane (203) and the xz plane is in the range of 20° to 25°.

3. The die for automated forging of hydraulic rails according to claim 1, characterized in that, The upper mold cavity (101) includes an upper oil pipe main body cavity (1011) and two support cavities (1012). The two support cavities (1012) are spaced apart on the same side of the upper oil pipe main body cavity (1011). Each support cavity (1012) is provided with a bending protrusion (1013). The bending protrusion (1013) includes a first inclined surface (10131) and a second inclined surface (10132). The first inclined surface (10131) is relative to the first inclined surface (10132). The two inclined surfaces (10132) are closer to the main cavity (1011) of the upper oil pipe, and the first inclined surface (10131) and the second inclined surface (10132) are intersected. The second inclined surface (10132) forms an angle β with the xy plane. The angle β satisfies the following relationship with the angle β1 formed between the second inclined surface (10132) of the corresponding bending protrusion (1013) in the final forging upper die of the final forging die (16) and the xy plane: β=β1+20°.

4. The die for automated forging of hydraulic rails according to claim 1, characterized in that, The upper mold cavity (101) has upper draft end faces (1014) at both ends, and each upper draft end face (1014) extends outward at an angle away from the center of the upper mold cavity (101). The lower mold cavity (201) has lower draft end faces (2011) at both ends, and each lower draft end face (2011) extends outward at an angle away from the center of the lower mold cavity (201). The draft angle of the upper draft end face (1014) at the same end relative to the yz plane is not equal to the draft angle of the lower draft end face (2011) relative to the yz plane.

5. The die for automated forging of hydraulic rails according to claim 4, characterized in that, The draft angle of the upper draft end face (1014) relative to the yz plane is γ1, and the draft angle of the lower draft end face (2011) relative to the yz plane is γ2. γ1 and γ2 satisfy the following condition: γ1 = γ2 + 3°.

6. The die for automated forging of hydraulic rails according to claim 1, characterized in that, The pre-forging upper die (1) has a first countersunk hole (102) extending along the z-axis. The upper push rod (3) is installed in the first countersunk hole (102). The upper push rod (3) has a first upper limit surface (301). The two ends of the upper elastic member (4) abut against the first upper limit surface (301) and the countersunk plane of the first countersunk hole (102), respectively. The pre-forging lower die (2) has a second countersunk hole (202) extending along the z-axis. The lower push rod (5) is installed in the second countersunk hole (202). The lower push rod (5) has a first lower limit surface (501) and a second lower limit surface (502) facing away from each other. The two ends of the lower elastic member (6) abut against the countersunk plane of the first lower limit surface (501) and the second countersunk hole (202), respectively. A lower limit plate (7) is provided at the lower end of the second countersunk hole (202). The second lower limit surface (502) is operablely abut against the lower limit plate (7).

7. The die for automated forging of hydraulic rails according to claim 6, characterized in that, The pre-forging lower die (2) is provided with a pad (9), a top plate (8) and a push rod connector (11). The pad (9) has a mounting hole (901) that runs through the z-axis. The top plate (8) is slidably installed in the mounting hole (901). The push rod connector (11) is connected to the upper end of the top plate (8). The upper end of the push rod connector (11) is opposite to the lower end face of the lower push rod (5), and there is a gap (10) between the upper end of the push rod connector (11) and the lower end face of the lower push rod (5). The upper end face of the push rod connector (11) is lower than the upper end face of the pad (9).

8. The die for automated forging of hydraulic rails according to claim 7, characterized in that, The top plate (8) has a groove (801) that extends through the top plate (8) along the z-axis and is connected to the lower mold cavity (201) through the second countersunk hole (202).

9. A forging method, characterized in that, Includes the following steps: S1. Billet heating: The rod-shaped billet is conveyed and heated synchronously through a medium-frequency furnace (12); S2, Temperature sorting: Receive the rod-shaped billet heated by the medium frequency furnace (12), and use the temperature automatic sorting instrument (22) to detect the temperature of the heated rod-shaped billet. Transport the qualified rod-shaped billet with the temperature within the preset range to the position waiting to enter the next process, and divert and remove the unqualified rod-shaped billet with the temperature outside the preset range. S3, Roll forging: The qualified bar billet is transported to the roll forging machine (23) by the first robot (13) for roll forging; S4, Spraying lubricant: While performing S3 roll forging of the billet, lubricant is sprayed onto the mold for automated forging of oil rails and the final forging mold (16) as described in any one of claims 1-8 by an automatic spraying device. S5, Pre-forging: After S3 and S4 are completed, the forged billet is fed into the lower mold cavity (201) of the pre-forging lower die (2) which is sprayed with lubricant by the second robot (14). The pre-forging upper die (1) moves downward along the z-axis and closes with the pre-forging lower die (2) to complete the pre-forging. After the pre-forging is completed, the pre-forging upper die (1) is lifted upward along the z-axis, and at the same time the upper ejector rod (3) is pushed downward along the z-axis to make the pre-forged part separate from the upper mold cavity (101). Then the lower ejector rod (5) is pushed upward along the z-axis to make the pre-forged part separate from the lower mold cavity (201). There is a time difference t between the ejection time of the lower ejector rod (5) and the ejection time of the upper ejector rod (3), and the range of t is 0.5 to 1 second. Then, remove the force applied to the upper push rod (3) that causes it to push downward, and the upper elastic element (4) applies an upward elastic force to the upper push rod (3) to cause it to move upward and reset; remove the force applied to the lower push rod (5) that causes it to push upward, and the lower elastic element (6) applies a downward elastic force to the lower push rod (5) to cause it to move downward and reset. S5. Final forging: The pre-forging part that has been removed from the lower mold cavity (201) of the pre-forging lower mold (2) is transferred to the final forging mold (16) for final forging by the third robot (15).

10. A pre-forging part, forged by the forging method as described in claim 9, characterized in that, The main oil pipe (17) includes an inlet pipe connector (18), a pressure test connector (20), two bolt column supports (19), and multiple injector seats (21) provided on the main oil pipe (17). The inlet pipe connector (18) is integrally connected to one end of the main oil pipe (17). The two bolt column supports (19) are spaced apart on the same side of the main oil pipe (17). Each bolt column support (19) has an injector seat (21) at both ends. The pressure test connector (20) is integrally connected to the other side of the main oil pipe (17) where the bolt column supports (19) are not provided. The main oil pipe (17) has a circular cross-section and a parting line extending along its axial direction. The main oil pipe (17) has oil pipe inclined surfaces (1701) formed on the outer wall surfaces on both sides of the parting line. The oil pipe inclined surfaces (1701) extend outward from the outer wall surface of the main oil pipe (17) in a direction opposite to the center of the cross-section of the main oil pipe (17). The angle between the oil pipe inclined surfaces (1701) and the xz plane is... The range is 20° to 25°; The end face of the oil inlet pipe joint (18) is divided by the horizontal center plane of the main oil pipe (17) to form a first upper draft surface (1801) and a second lower draft surface (1802). The draft angle of the first upper draft surface (1801) relative to the vertical direction is... Draft angle relative to the vertical direction of the second lower draft surface (1802) They are not equal, and and The following conditions must be met: = +3°; Each bolted column bracket (19) includes an extension section (1901) and a bent section (1902). One end of the extension section (1901) is integrally connected to the outer wall of the main oil pipe (17), and the other end of the extension section (1901) extends outward at an angle away from the center of the cross-section of the main oil pipe (17). The bent section (1902) is integrally connected to the other end of the extension section (1901), and the inner wall surface of the bent section (1902) forms an angle with the horizontal center plane of the main oil pipe (17). An angle is formed between the inner wall surface of the corresponding bent section (1902) on the final forging of the oil rail to be processed and the horizontal center plane of the main oil pipe (17). included angle and included angle The following conditions must be met: = +20°.

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