A semi-piercing combined forming closed-die forging steel piston skirt mold and processing method

Abstract

The application provides a semi-punching composite forming closed forging steel piston skirt mold and a processing method. The semi-punching composite forming closed forging steel piston skirt mold comprises a hot die section press slide and a press table, the hot die section press slide is slidingly installed at the top inside the press table; a lower closed forging die is arranged at the middle of the bottom inside the press table; a left oil pressure punching unit is arranged at the left side of the bottom inside the press table, and a right oil pressure punching unit is arranged at the right side of the bottom inside the press table. By adopting the 2500T main press closed forging forming and the double-side synchronous oil pressure semi-punching composite structure, the piston pin hole is synchronously extruded and semi-punched in the die closing and forging pressing stage, only about 10mm thin skin is reserved, the subsequent drilling depth is greatly shortened, the no-flash closed forging and the pin hole preforming composite integrated forming are synchronously realized, and the pain points of large material loss, low pin hole processing efficiency and high production cost in the industry are solved.

Description

Technical Field

[0001] This invention relates to the field of piston forging, and more particularly to a semi-punching composite forming closed forging steel piston skirt mold and its processing method. Background Technology

[0002] The pin hole of the forged steel piston skirt runs through the thick skirt area. The current mainstream processing technology in the industry is divided into three categories: open forging + subsequent integral drilling and milling of the pin hole, pure closed unidirectional forging, and step-forging followed by punching. All of these have obvious shortcomings.

[0003] 1. Open forging + subsequent integral drilling and milling of pin holes: Traditional open forging produces a lot of flash and has a low material utilization rate; the pin holes are not pre-formed after forging and need to be drilled through the entire thick skirt, resulting in long cutting stroke, large tool wear, long single-machine processing cycle, and high processing cost.

[0004] 2. Pure closed unidirectional forging process: Conventional closed molds can only achieve the forming of the piston skirt without flash, and cannot simultaneously pre-punch the pin hole area. The pin hole still needs to be milled and drilled through the whole machine, which cannot reduce the deep hole processing time and material consumption.

[0005] 3. Step-by-step forging and punching scheme: Forging and punching are carried out in two separate sets of equipment and clamped twice. The hot forging is prone to deformation during transfer and cooling. Repeated positioning leads to dimensional deviations. At the same time, the investment in production line equipment and manual transfer costs are high.

[0006] Existing technologies cannot simultaneously complete the pin hole semi-pre-punching forming while performing closed-loop flashless forging, and the drilling and milling process for the complete through-hole of the thick skirt cannot be simplified. It is difficult to simultaneously optimize material utilization, machining efficiency, and unit production cost.

[0007] Therefore, it is necessary to provide a semi-punching composite forming closed forging steel piston skirt mold and processing method to solve the above-mentioned technical problems. Summary of the Invention

[0008] This invention provides a semi-punching composite forming closed forging steel piston skirt mold, which solves the problems of existing technology being unable to simultaneously complete the pin hole semi-pre-punching forming while performing closed flash-free forging, the inability to simplify the drilling and milling process for the complete through-hole of the thick skirt, and the difficulty in simultaneously optimizing material utilization, machining efficiency, and unit production cost.

[0009] To solve the above-mentioned technical problems, the present invention provides a semi-punching composite forming closed forging steel piston skirt mold, comprising: a hot die section press slide and a press worktable;

[0010] The hot die section press slide is slidably installed on the top inside the press workbench, and an upper closed forging die is fixedly installed in the middle of the bottom of the hot die section press slide.

[0011] A closed-type forging die is provided in the middle of the bottom of the press worktable, and a hot-forged steel piston skirt blank is provided in the middle of the top of the closed-type forging die.

[0012] A left-side hydraulic punching unit is located on the left side of the bottom inside the press table, and a right-side hydraulic punching unit is located on the right side of the bottom inside the press table.

[0013] Preferably, both the left and right hydraulic punching units are provided with punching pins at one end.

[0014] Preferably, a lower die ejector mechanism is provided in the middle of the bottom of the lower closed forging die.

[0015] Preferably, the hot-forged steel piston skirt blank has pin holes and semi-through holes on both sides.

[0016] Preferably, a support plate is provided on the rear side of the press worktable, and a second lifting member is fixedly installed in the middle of the support plate. A clamping device is fixedly connected to the end of the output shaft of the second lifting member.

[0017] Preferably, the clamping device includes a fixed plate, a sliding groove, a first lifting member, and a clamping plate. The fixed plate is fixedly connected to the output shaft end of the second lifting member. The sliding groove is opened in the middle of one side of the surface of the fixed plate. The two first lifting members are respectively fixedly installed on both sides of the outer surface of the fixed plate. The clamping plate is fixedly connected to the output shaft end of the first lifting member.

[0018] Preferably, a base is fixedly installed at the bottom of the support plate, and support boxes are fixedly installed on the front and back sides of the left and right sides of the outer surface of the base, and a movable wheel is rotatably installed at the bottom center of the support box.

[0019] This invention also proposes a processing method for the semi-punching composite forming closed forged steel piston skirt mold, the steps of which are as follows:

[0020] First, the heated steel piston blank is placed in the lower closed forging die cavity. The slide block of the hot die forging hydraulic press drives the upper closed forging die to move downward. The punching pins of the left and right hydraulic punching units will extend 1 / 4 arc distance and maintain constant pressure. The upper and lower closed forging dies are completely closed to form a sealed closed cavity, which compresses the hot forged steel piston skirt blank as a whole, completing the closed forging forming of the complete outline of the hot forged steel piston skirt blank without flash.

[0021] When the upper and lower closed forging dies are fully locked and pressure is maintained, and the hot-forged steel piston skirt blank is in the extrusion and shaping state, the left and right hydraulic punching units on the left and right sides of the die synchronously drive the punching pin to release the pressure and feed laterally. The punching pin is synchronously extruded along the semi-through hole of the piston skirt thick skirt pin hole. The feed depth of the punching pin is controlled to be 1 / 2 of the total thickness of the thick skirt. After the two punching pins on both sides are extruded towards each other, a 10mm thick connecting skin is reserved in the middle of the semi-through hole of the pin hole. Then the left and right hydraulic punching units drive the punching pin to retract synchronously.

[0022] After the punched pin retracts into the thick side wall of the piston skirt, the upper closed forging die moves upward to open, and the lower die ejector mechanism in the lower closed forging die ejects upward to form the hot forged steel piston skirt forging.

[0023] The pin hole semi-through hole of the hot forged steel piston skirt forging has only 10mm of thin skin remaining. It is transferred to a double-headed special drilling machine to drill through it in one go to complete the pin hole finishing, without the need for drilling and milling along the full thickness of the skirt.

[0024] Compared with related technologies, the semi-punching composite forming closed forging steel piston skirt mold and processing method provided by the present invention have the following beneficial effects:

[0025] This invention provides a semi-punching composite forming closed forging steel piston skirt mold. By adopting a closed forging forming with two main presses and a double-sided synchronous hydraulic semi-punching composite structure, the piston pin hole is simultaneously extruded and semi-punched during the die closing and forging stage, leaving only a thin connecting skin of about 10mm, which greatly shortens the subsequent drilling depth. It simultaneously realizes flash-free closed forging and pin hole pre-forming composite integral forming, solving the pain points of high material loss, low efficiency of pin hole processing, and high production cost in the industry. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the first embodiment of a semi-punching composite forming closed forging steel piston skirt mold provided by the present invention.

[0027] Figure 2 for Figure 1 The diagram shows a punching pattern for a hot-forged steel piston skirt blank.

[0028] Figure 3 for Figure 1 The diagram shows a comparison of the pin holes of the forged semi-finished and finished hot-forged steel piston skirt blank.

[0029] Figure 4 for Figure 1 The diagram shows the motion process of the double-sided hydraulic semi-punching mechanism.

[0030] Figure 5 This is a schematic diagram of the second embodiment of a semi-punching composite forming closed forging steel piston skirt mold provided by the present invention;

[0031] Figure 6 for Figure 5 The diagram shows the structure of the clamping device.

[0032] The diagram is labeled as follows: 1. Hot forging press slide block; 2. Upper closed forging die; 3. Lower closed forging die; 4. Left 500T hydraulic punching unit; 5. Right 500T hydraulic punching unit; 6. Punching pin; 7. Hot forged steel piston skirt blank; 8. Lower die ejector mechanism; 9. Press worktable; 10. Pin hole semi-through hole; 11. Clamping device; 111. Fixed plate; 112. Slide groove; 113. First lifting component; 114. Clamping plate; 12. Second lifting component; 13. Support plate; 14. Base; 15. Support box; 16. Moving wheel. Detailed Implementation

[0033] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0034] First Embodiment

[0035] Please refer to the following: Figure 1 , Figure 2 , Figure 3 and Figure 4 ,in, Figure 1 This is a schematic diagram of the first embodiment of a semi-punching composite forming closed forging steel piston skirt mold provided by the present invention. Figure 2 for Figure 1 The diagram shows a punching pattern for a hot-forged steel piston skirt blank. Figure 3 for Figure 1 The diagram shows a comparison of the pin holes of the forged semi-finished and finished hot-forged steel piston skirt blank. Figure 4 for Figure 1 The diagram shows the motion process of the double-sided hydraulic semi-punching mechanism.

[0036] A semi-punching composite forming closed forged steel piston skirt mold includes: a hot die section press slide 1 and a press worktable 9;

[0037] The hot die section press slide block 1 is slidably installed on the top inside the press workbench 9, and the bottom center of the hot die section press slide block 1 is fixedly installed with an upper closed forging die 2.

[0038] The lower closed forging die 3 is located in the middle of the bottom of the press worktable 9, and a hot forged steel piston skirt blank 7 is provided in the middle of the top of the lower closed forging die 3.

[0039] The left 500T hydraulic punching unit 4 is located on the left side of the bottom of the press workbench 9, and the right 500T hydraulic punching unit 5 is located on the right side of the bottom of the press workbench 9.

[0040] Both the left 500T hydraulic punching unit 4 and the right 500T hydraulic punching unit 5 are provided with punching pins 6 at one end.

[0041] The lower die ejector mechanism 8 is provided in the middle of the bottom of the lower closed forging die 3.

[0042] Both sides of the hot-forged steel piston skirt blank 7 are provided with pin holes and semi-through holes 10.

[0043] The upper closed forging die 2 and the lower closed forging die 3 are compatible with a 2500T hot forging hydraulic press. The cavity is a completely sealed closed structure, and there are no flashes during the forging process, which improves the material utilization rate.

[0044] The left 500T hydraulic punching unit 4 and the right 500T hydraulic punching unit 5 are equipped with a rated 500T small hydraulic press, which independently drives the punching pin 6. During the mold closing and pressure holding stage, the pin is fed synchronously and the pin hole and semi-through hole 10 are formed by bidirectional half extrusion, and a 10mm connecting skin is reserved.

[0045] The lower die ejector mechanism 8 is used for ejecting the material from the die after forging and forming, and after the pin retracts, to prevent the hot forging from getting stuck and deformed. It can be a hydraulic cylinder.

[0046] Equipped with a dual-head drilling machine, it is designed for drilling short-stroke holes in 10mm thin skin, resulting in low tool wear and fast processing cycle.

[0047] The 500T hydraulic punching unit 4 on the left and the 500T hydraulic punching unit 5 on the right are designed with bidirectional half-extrusion and half-punching. The single-sided pin is only extruded half-thickness, which greatly reduces the force on a single set of punching pins 6, extends the life of the punching die, and controls the thickness of the middle skin to be uniform and stable. It takes into account both the durability of the die and the convenience of subsequent processing. Multiple technical effects are optimized in synergy, which has outstanding creativity.

[0048] The complete set of molds consists of a conventional hot forging press, a small hydraulic unit, and standard punching pins. The parts are highly interchangeable and require low investment for modification. It is suitable for batch forging of piston skirts of various specifications of large-diameter steel cylinders and can be directly connected to existing double-head drilling special machine production lines without the need for major modifications to downstream equipment. It is easy to promote and implement throughout the industry.

[0049] Closed-loop flashless forging eliminates flash material loss, significantly improves the utilization rate of hot forging raw materials, and reduces the raw material cost of a single forging. The pin hole forging stage pre-forms the pin hole, leaving only a 10mm thin connecting skin, eliminating the need for a full-thickness deep drilling and milling process. This greatly shortens the drilling and cutting stroke, simultaneously reducing tool wear, coolant consumption, and single-machine processing time, resulting in a significant decrease in overall machining costs.

[0050] Forging and semi-punching are completed simultaneously in one clamping at the same station, eliminating the need for secondary heating and positioning of forgings during transfer. This avoids dimensional deformation caused by cooling of high-temperature forgings during transfer, and improves the dimensional accuracy and coaxiality consistency of piston pin holes.

[0051] The dual-sided 500T hydraulic press performs opposing extrusion, halving the single-sided punching load, improving the thermal fatigue life of punching pins and die holders, and reducing the frequency of die maintenance and spare parts costs.

[0052] By combining two processes into a single machine, the number of production line equipment and manual transfer stations is reduced, the overall production cycle of piston skirts is shortened, and the overall production efficiency of forging and pin hole processing is greatly improved, resulting in a significant increase in overall production benefits.

[0053] The working principle of the semi-punching composite forming closed forging steel piston skirt mold provided by this invention is as follows:

[0054] During operation, the heated steel piston blank 7 is first placed in the cavity of the lower closed forging die 3. The slide block 1 of the 2500T hot die forging hydraulic press drives the upper closed forging die 2 to move downward. The punching pins 6 of the left 500T hydraulic punching unit 4 and the right 500T hydraulic punching unit 5 will extend 1 / 4 arc distance and maintain constant pressure. The upper closed forging die 2 and the lower closed forging die 3 are completely closed to form a sealed closed cavity, which extrudes the hot forged steel piston skirt blank 7 as a whole, and completes the closed forging of the hot forged steel piston skirt blank 7 with a complete outline and no flash.

[0055] When the upper closed forging die 2 and the lower closed forging die 3 are fully locked and pressure is maintained, and the hot forged steel piston skirt blank 7 is in the extrusion and shaping state, the left 500T hydraulic punching unit 4 and the right 500T hydraulic punching unit 5 on the left and right sides of the die synchronously drive the punching pin 6 to release the pressure and feed laterally. The punching pin 6 is synchronously extruded in opposite directions along the semi-through hole 10 of the piston skirt thick skirt pin hole. The feed depth of the punching pin 6 is controlled to be 1 / 2 of the total thickness of the thick skirt. After the two punching pins 6 are extruded in opposite directions, a connecting skin of about 10mm thickness is reserved in the middle of the semi-through hole 10 of the pin hole. Then the left 500T hydraulic punching unit 4 and the right 500T hydraulic punching unit 5 drive the punching pin 6 to retract synchronously.

[0056] After the punched pin 6 retracts into the thick side wall of the piston skirt, the upper closed forging die 2 moves upward to open the die, and the lower die ejector mechanism 8 in the lower closed forging die 3 pushes the hot forged steel piston skirt forging upward.

[0057] The pin hole semi-through hole 10 of the hot forged steel piston skirt forging has only about 10mm of thin skin remaining. It is transferred to a double-head special drilling equipment to drill through it in one go to complete the pin hole finishing, without the need to drill and mill along the full thickness of the skirt.

[0058] Compared with related technologies, the semi-punching composite forming closed forging steel piston skirt mold provided by the present invention has the following beneficial effects:

[0059] This invention provides a semi-punching composite forming closed forging steel piston skirt mold. By adopting a 2500T main press for closed forging and a double-sided synchronous hydraulic semi-punching composite structure, the piston pin hole is simultaneously extruded and semi-punched during the die closing and forging stage, leaving only a thin connecting skin of about 10mm, which greatly shortens the subsequent drilling depth. It simultaneously realizes flash-free closed forging and pin hole pre-forming composite integral forming, solving the pain points of high material loss, low efficiency of pin hole processing, and high production cost in the industry.

[0060] Second Embodiment

[0061] Please refer to the following: Figure 5 and Figure 6 Based on the semi-punching composite forming closed forging steel piston skirt mold provided in the first embodiment of this application, the second embodiment of this application proposes another semi-punching composite forming closed forging steel piston skirt mold. The second embodiment is merely a preferred embodiment of the first embodiment, and the implementation of the second embodiment will not affect the separate implementation of the first embodiment.

[0062] Specifically, the second embodiment of this application provides a semi-punching composite forming closed forging steel piston skirt mold in that a support plate 13 is provided on the rear side of the press worktable 9, a second lifting member 12 is fixedly installed in the middle of the support plate 13, and a clamping device 11 is fixedly connected to the output shaft end of the second lifting member 12.

[0063] The clamping device 11 includes a fixed plate 111, a sliding groove 112, a first lifting member 113, and a clamping plate 114. The fixed plate 111 is fixedly connected to the output shaft end of the second lifting member 12. The sliding groove 112 is opened in the middle of one side of the surface of the fixed plate 111. The two first lifting members 113 are respectively fixedly installed on both sides of the outer surface of the fixed plate 111. The clamping plate 114 is fixedly connected to the output shaft end of the first lifting member 113.

[0064] A base 14 is fixedly installed at the bottom of the support plate 13. Support boxes 15 are fixedly installed on the left and right sides and the front and rear sides of the outer surface of the base 14. A movable wheel 16 is rotatably installed at the bottom center of the support box 15.

[0065] Both the first lifting component 113 and the second lifting component 12 adopt an electric telescopic rod device.

[0066] The movable wheel 16 is controlled to rotate by the output shaft of the servo motor, which is mounted on the outer surface of the support box 15.

[0067] The working principle of the semi-punching composite forming closed forging steel piston skirt mold provided by this invention is as follows:

[0068] During operation, after the forging is completed, the hot-forged steel piston skirt blank 7 is lifted by the lower die ejector mechanism 8. The moving wheel 16 moves forward and approaches the press worktable 9. The output shafts of the first lifting members 113 on both sides of the outer surface of the fixed plate 111 approach each other, driving the two clamping plates 114 to approach each other and clamp the hot-forged steel piston skirt blank 7.

[0069] The moving wheel 16 moves backward, driving the entire clamping device 11 and the hot-forged steel piston skirt blank 7 to move backward, facilitating the transfer and storage of the hot-forged steel piston skirt blank 7.

[0070] Compared with related technologies, the semi-punching composite forming closed forging steel piston skirt mold provided by the present invention has the following beneficial effects:

[0071] This invention provides a semi-punching composite forming closed forging steel piston skirt mold, which realizes automatic clamping and smooth transfer of the forged workpiece through the clamping device 11 and the base 14, reducing manual intervention, reducing manual operation steps, avoiding problems such as burns, and improving process safety.

[0072] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A semi-punching composite forming closed forged steel piston skirt mold, characterized in that, include: Hot mold section press slide and press worktable; The hot die section press slide is slidably installed on the top inside the press workbench, and an upper closed forging die is fixedly installed in the middle of the bottom of the hot die section press slide. A closed-type forging die is provided in the middle of the bottom of the press worktable, and a hot-forged steel piston skirt blank is provided in the middle of the top of the closed-type forging die. A left-side hydraulic punching unit is located on the left side of the bottom inside the press table, and a right-side hydraulic punching unit is located on the right side of the bottom inside the press table.

2. The semi-punching composite forming closed forging steel piston skirt mold according to claim 1, characterized in that, Both the left and right hydraulic punching units are equipped with punching pins at one end.

3. The semi-punching composite forming closed forging steel piston skirt mold according to claim 1, characterized in that, The lower die ejector mechanism is provided in the middle of the bottom of the lower closed forging die.

4. The semi-punching composite forming closed forging steel piston skirt mold according to claim 1, characterized in that, Both sides of the hot-forged steel piston skirt blank are provided with pin holes and semi-through holes.

5. The semi-punching composite forming closed forging steel piston skirt mold according to claim 1, characterized in that, A support plate is provided on the rear side of the press worktable, and a second lifting member is fixedly installed in the middle of the support plate. A clamping device is fixedly connected to the end of the output shaft of the second lifting member.

6. The semi-punching composite forming closed forging steel piston skirt mold according to claim 5, characterized in that, The clamping device includes a fixed plate, a sliding groove, a first lifting member, and a clamping plate. The fixed plate is fixedly connected to the output shaft end of the second lifting member. The sliding groove is opened in the middle of one side of the surface of the fixed plate. The two first lifting members are respectively fixedly installed on both sides of the outer surface of the fixed plate. The clamping plate is fixedly connected to the output shaft end of the first lifting member.

7. A semi-punching composite forming closed forging steel piston skirt mold according to claim 5, characterized in that, A base is fixedly installed at the bottom of the support plate, and support boxes are fixedly installed on the left and right sides and the front and back sides of the outer surface of the base. A movable wheel is rotatably installed in the middle of the bottom of the support box.

8. The processing method of the semi-punching composite forming closed forged steel piston skirt mold according to claim 1, characterized in that, The steps are as follows: First, the heated steel piston blank is placed in the lower closed forging die cavity. The slide block of the hot die forging hydraulic press drives the upper closed forging die to move downward. The punching pins of the left and right hydraulic punching units will extend 1 / 4 arc distance and maintain constant pressure. The upper and lower closed forging dies are completely closed to form a sealed closed cavity, which compresses the hot forged steel piston skirt blank as a whole, completing the closed forging forming of the complete outline of the hot forged steel piston skirt blank without flash. When the upper and lower closed forging dies are fully locked and pressure is maintained, and the hot-forged steel piston skirt blank is in the extrusion and shaping state, the left and right hydraulic punching units on the left and right sides of the die synchronously drive the punching pin to release the pressure and feed laterally. The punching pin is synchronously extruded along the semi-through hole of the piston skirt thick skirt pin hole. The feed depth of the punching pin is controlled to be 1 / 2 of the total thickness of the thick skirt. After the two punching pins on both sides are extruded towards each other, a 10mm thick connecting skin is reserved in the middle of the semi-through hole of the pin hole. Then the left and right hydraulic punching units drive the punching pin to retract synchronously. After the punched pin retracts into the thick side wall of the piston skirt, the upper closed forging die moves upward to open, and the lower die ejector mechanism in the lower closed forging die ejects upward to form the hot forged steel piston skirt forging. The pin hole semi-through hole of the hot forged steel piston skirt forging has only 10mm of thin skin remaining. It is transferred to a double-headed special drilling machine to drill through it in one go to complete the pin hole finishing, without the need for drilling and milling along the full thickness of the skirt.

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