A hot forging steel piston skirt trimming-piercing-finishing three-in-one device and processing method for inhibiting hot deformation

Abstract

A hot forging steel piston skirt trimming-punching-finishing three-in-one device and processing method for inhibiting hot deformation belong to the technical field of mechanical processing, and are directed to trimming punching production process control of hot forging steel piston skirt forgings with flash or needing punching or both. The four process controls of holding, trimming, punching and finishing of the hot forging steel piston skirt are realized through mutual cooperation of three high-temperature-resistant die springs, and the precision of the piston skirt is greatly improved. The trimming device is simple in structure and safe, can be classified according to different specifications of different cylinder diameter piston skirts, and can meet the high-precision trimming requirements of all hot forging steel piston skirts. The present application innovatively proposes the technical scheme of "three sets of customized rectangular springs cooperative control + synchronous composite process", and for the first time realizes "one clamping and three processes completed simultaneously" of the hot forging steel piston skirt, solves the hot deformation and efficiency bottleneck from the aspects of process principle and structure design, and has remarkable creativity and practicality.

Description

Technical Field

[0001] This invention belongs to the field of machining technology, specifically relating to a three-in-one device and processing method for suppressing hot-deformed steel piston skirt trimming, punching, and finishing. Background Technology

[0002] As a core moving component of diesel engines, the hot-forged steel piston skirt's post-processing precision directly determines the engine's power performance and reliability. Currently, the industry generally adopts a "single-process, independent equipment, step-by-step processing" model for the edge trimming, punching, and finishing processes of hot-forged steel piston skirts. This model suffers from three major long-standing unresolved core technical challenges in this field:

[0003] ① Uncontrollable hot-state deformation during punching: After hot forging, the forged steel piston skirt usually requires further processing such as trimming and punching. Both trimming and punching are usually done hot, which easily causes deformation of the thin edge of the piston skirt. This deformation makes it impossible to improve the dimensional accuracy of the thin edge of the piston skirt, thus failing to meet the increasingly high precision requirements of customers for forged steel piston skirts.

[0004] ② Poor spring selection and compatibility: Existing devices mostly use cylindrical springs or nitrogen springs. Cylindrical springs have a low resistance to off-center loads and a severely insufficient lifespan under hot conditions. They are prone to excessive burrs on the forging edges due to off-center loads, as well as failures in the cutting tooling. Nitrogen springs have a low upper temperature limit and are prone to seal failure in hot forging environments, resulting in high maintenance frequency. Although disc springs have better temperature resistance, they have large force transmission errors, are inconvenient to assemble, and cannot achieve precise preload control.

[0005] ③ The contradiction between process efficiency and automation: The three processes require three independent machines and three manual clamping operations, resulting in a long processing cycle for a single piece. Furthermore, the transfer between machines can easily lead to a large drop in temperature of the forging, which is not conducive to the connection of subsequent heat treatment processes. During subsequent punching, the cut is prone to deformation and burrs. At the same time, the process intervals of the step-by-step processing require the additional design of transfer mechanisms for automation integration, thus continuing the high degree of integration.

[0006] This invention primarily addresses the process control of punching hot-forged steel piston skirt forgings with flash, punching, or both. By utilizing three types of high-temperature resistant die springs in coordination, it achieves control over four processes: clamping, trimming, punching, and finishing of the hot-forged steel piston skirt. This solves the problem of deformation during punching, significantly improving the precision of the piston skirt. This punching device is not only simple and safe in structure, but also allows for quick and convenient product changeover, low maintenance costs, and can classify piston skirts according to different cylinder diameters to meet the high-precision punching requirements of all hot-forged steel piston skirts. Summary of the Invention

[0007] The purpose of this invention is to propose a three-in-one device and processing method for hot-forged steel piston skirt edge trimming, punching, and finishing to suppress hot deformation. This patent addresses the aforementioned pain points and breaks through the traditional design concept of "single process, single spring". It innovatively proposes a technical solution of "three sets of customized rectangular springs working together + synchronous composite process", which for the first time realizes "one clamping and three processes completed simultaneously" for hot-forged steel piston skirt. It solves the bottleneck of hot deformation and efficiency from the perspective of process principle and structural design, and has significant creativity and practicality.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0009] A three-in-one device for edge trimming, punching, and finishing of hot-forged steel piston skirts to suppress hot deformation, comprising an upper slide block and an upper die holder connected to each other, and a lower slide block and a lower die holder connected to each other, wherein the upper die holder and the lower die holder are arranged facing each other, and further comprising:

[0010] The spring seat has a clamping spring guide post in the middle, on which a clamping spring is fitted; the spring seat has slit spring guide posts around its perimeter, on which slit springs are fitted; the top of the slit spring guide post is fixed to the upper mold base, and the bottom extends out of the outer side of the spring seat and is provided with a locking bolt; the spring seat is installed below the upper mold base through the slit spring guide posts, and a certain gap is left between the spring seat and the upper mold base.

[0011] The upper finishing mold is installed in the middle of the spring seat, and its top is connected to the bottom of the clamping spring;

[0012] The trimming die is installed in the middle of the spring seat and is located on the outer periphery of the bottom end face of the upper finishing die;

[0013] The lower die, installed on top of the lower die base, is used to support the piston skirt of the hot forged steel to be processed;

[0014] The stripper plate, which is ring-shaped, is placed on the outer periphery of the top end face of the lower die, and its vertical direction corresponds to the trimming die; the bottom of the stripper plate is connected to the lower die base by a floating spring, and the floating spring has a spring column inside.

[0015] As a preferred embodiment of the present invention, the cutting spring, the clamping spring, and the floating spring are all rectangular springs. Meanwhile, the punched connecting skin of the hot-forged steel piston skirt to be processed is provided with a U-shaped boss, and a U-shaped slot for auxiliary positioning is provided at the corresponding position in the lower mold cavity, achieving precise positioning between the hot-forged steel piston skirt and the lower mold.

[0016] In addition, the present invention also proposes a processing method for the three-in-one device for suppressing hot-deformation hot-forged steel piston skirt trimming-punching-finishing, the steps of which are as follows:

[0017] The first stage is the positioning of the hot forging reference.

[0018] With the mold frame open, the piston skirt is positioned on the lower mold by the square punched holes and the bottom boss of the hot forged steel piston skirt.

[0019] The second stage involves thermal flexible clamping;

[0020] The upper finishing die, punch, and trimming die connected to the upper slider begin to move downward with the upper die base; the upper finishing die first contacts the hot forged steel piston skirt and hugs the skirt tightly;

[0021] The third stage is pre-cutting and simultaneous finishing.

[0022] As the upper slider continues to move downwards, the cutting edge of the trimming die begins to contact the flash of the hot-forged steel piston skirt. Due to the increasing elasticity of the trimming spring, the cutting edge of the trimming die gradually increases the punching force until the spring seat with the trimming spring guide post contacts the upper die seat of the die set. When the punching force of the trimming die becomes the pressure applied by the slider on the equipment, the flash of the hot-forged steel piston skirt is cut off and pressed by the trimming die onto the stripper plate with the floating spring. At the same time, the hot-forged steel piston skirt is placed and fixed on the lower die. After the upper finishing die holds the hot-forged steel piston skirt tightly, it cannot move downwards and can only compress the upper holding spring. Under the action of the holding spring, the cavity position, thin skirt position, and thick skirt position of the hot-forged steel piston skirt are finished. The punching punch connected to the fixed block moves downwards with the upper slider and gradually contacts the position where the punching skin of the hot-forged steel piston skirt is located.

[0023] The fourth stage is high-precision punching;

[0024] The upper slider continues to move downwards, and the cutting die compacts the flash left on the stripper plate equipped with the floating spring. As the upper slider continues to move downwards, it continues to compress the floating spring. After the punching punch contacts the punching strip of the hot forged steel piston skirt, it continues to move downwards and completes the punching action under the pressure applied by the upper slider. The punching strip falls down, and the punching punch will continue to move downwards until the lower slider reaches the set lower stop point.

[0025] The fifth stage is orderly reset;

[0026] After the upper slider reaches the lower stop point, it begins to reset upwards. At this time, the floating spring extends, pushing the stripper plate with the punched flash upwards along with the trimming die, the upper finishing die, the punching punch, and the upper slider. Then, the floating spring returns to its own length, the trimming spring in the spring seat returns to its preload length, and the clamping spring in the upper finishing die returns to its preload length. The upper slider returns to the upper stop point.

[0027] The sixth stage is automated cleanup;

[0028] After the upper slider returns to the upper stop point, the stripper plate returns to its extended state due to the floating spring, pushing out the cut-off flash; the punched strip is punched into the hole of the lower die base; the operator sequentially clamps away the hot forged steel piston skirt, the punched flash, and the punched strip after punching.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0030] ① It can achieve the three-in-one finishing, trimming, and punching of hot-forged steel piston skirt forgings, greatly improving production efficiency.

[0031] ② While finishing, edge trimming and punching are completed, minimizing deformation caused by edge trimming and punching, improving the dimensional accuracy and surface profile accuracy of the piston skirt cavity, and significantly enhancing the product's competitiveness.

[0032] ③The device and system are relatively simple, easy to assemble, have stable functions, and are highly applicable.

[0033] ④ It promotes the transformation of hot forged steel piston skirt processing from "step-by-step extensive" to "composite precision", providing the industry with a standardized solution for hot composite processing, which can drive the technological upgrading of related equipment (such as presses and robotic arms). Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the three-in-one device for suppressing hot deformation of hot forged steel piston skirt trimming, punching, and finishing (showing the state of each component when the hot forging is positioned at the reference point in the first stage).

[0035] Figure 2 This is a schematic diagram of the structure of a hot-forged steel piston skirt (A and B are the bottom view and top view, respectively).

[0036] Figure 3 This is a structural schematic diagram of the upper finishing mold (A and B are the top view and the sectional view along AA, respectively).

[0037] Figure 4 This is a schematic diagram of the spring seat (A and B are the top view and the sectional view along BB, respectively).

[0038] Figure 5 This is a structural schematic diagram of the lower mold (A and B are the top view and the CC-direction sectional view, respectively).

[0039] Figure 6 The second stage, showing the state of each component during the hot flexible clamping, is illustrated.

[0040] Figure 7 The diagram shows the state of each component during the third stage, when pre-cutting and synchronous finishing are performed.

[0041] Figure 8 The fourth stage, the state of each component during high-precision punching, is shown.

[0042] Figure 9 The fifth stage, the state of each component during orderly reset, is shown.

[0043] Figure 10 The sixth stage, showing the status of each component during automated cleaning, is illustrated.

[0044] The meanings of the reference numerals in the figure are as follows:

[0045] 1-Upper slider, 2-Upper mold base, 3-Guide post, 4-Guide sleeve, 5-Fixing block, 6-Spring seat, 7-Trimming spring, 8-Punching punch, 9-Clamping spring, 10-Upper finishing mold, 11-Trimming spring guide post, 12-Trimming mold, 13-Hot forged steel piston skirt, 14-Stripping plate, 15-Spring post, 17-Floating spring, 19-Lower mold, 20-Lower mold base, 21-Lower slider.

[0046] 13-1-Punching with skin, 13-2-Flash. Detailed Implementation

[0047] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings.

[0048] Example 1

[0049] like Figure 1-5 As shown, the hot-forged steel piston skirt trimming-punching-finishing three-in-one device for suppressing hot deformation proposed in this invention mainly includes:

[0050] The upper slider 1 and upper mold base 2 are connected to each other, and the lower slider 21 and lower mold base 20 are connected to each other. The upper mold base 2 and lower mold base 20 are arranged facing each other.

[0051] The spring seat 6 has a clamping spring guide post in the middle, on which a clamping spring 9 is fitted; the spring seat 6 has slit spring guide posts 11 around its perimeter, on which a slit spring 7 is fitted; the top of the slit spring guide post 11 is fixed to the upper mold base 2, and the bottom extends out of the outer side of the spring seat 6 and is provided with a locking bolt. The spring seat 6 is installed below the upper mold base 2 through the slit spring guide posts 11, and a certain gap is left between the spring seat 6 and the upper mold base.

[0052] The upper finishing mold 10 is installed in the middle of the spring seat 6, and its top is connected to the bottom of the clamping spring 9.

[0053] The trimming die 12 is installed in the middle of the spring seat 6 and is located on the outer periphery of the bottom end face of the upper finishing die 10.

[0054] The lower die 19 is installed on top of the lower die base 20 and is used to support the hot forged steel piston skirt 13 to be processed.

[0055] The stripper plate 14 is ring-shaped and is placed on the outer periphery of the top end face of the lower mold 19, and its vertical direction corresponds to the trimming mold 12. The bottom of the stripper plate 14 is installed and connected to the lower mold base 20 through a floating spring 17, and the floating spring 17 is provided with a spring column 15.

[0056] Example 2

[0057] This device, based on the upper slide motion of a press, utilizes three sets of rectangular springs with differentiated parameters (clamping spring, trimming spring, and floating spring) in conjunction with a "dual guide post and guide sleeve system" to complete high-precision hot stamping in six stages. Please refer to [link / reference]. Figure 1 , 6 As shown in Figure -10, the technical details and innovative designs for each stage of the working sequence are as follows:

[0058] Phase 1, hot forging reference positioning ( Figure 1 (As shown).

[0059] With the mold frame open, the piston skirt 13 is positioned on the lower mold 19 by the bottom boss of the square punched skin 13-1 on the hot forged steel piston skirt 13.

[0060] The second stage involves thermal flexible clamping ( Figure 6 (As shown).

[0061] The upper finishing die 10, punching punch 8, and trimming die 12, connected to the upper slider 1, begin to move downwards with the upper die base 2. The upper finishing die 10 first contacts the hot-forged steel piston skirt 13 and grips the skirt tightly.

[0062] The third stage involves pre-cutting and simultaneous finishing. Figure 7 (As shown).

[0063] As the upper slider 1 continues to move downwards, the cutting edge of the trimming die 12 begins to contact the flash 13-2 of the hot-forged steel piston skirt 13. Due to the increasing elasticity of the trimming spring 7, the cutting edge of the trimming die 12 gradually increases its punching force until the spring seat 6 with the trimming spring guide post 11 contacts the upper die holder 2 of the die set. When the punching force of the trimming die 12 becomes the pressure applied by the slider 1 on the equipment, the flash 13-2 of the hot-forged steel piston skirt 13 is cut off and pressed by the trimming die 12 onto the stripper plate 14 with the floating spring 17. Simultaneously, the hot-forged steel piston skirt 13 is positioned and fixed on the lower die 19. After the upper finishing die 10 clamps the hot-forged steel piston skirt 13, it cannot move downwards and can only compress the clamping spring 9. Under the action of the clamping spring 9, the cavity position, thin skirt position, and thick skirt position of the hot-forged steel piston skirt 13 are finished. As the upper slider moves down, the punch 8 connected to the fixed block 5 gradually contacts the punching skin 13-1 of the hot forged steel piston skirt 13.

[0064] The fourth stage is high-precision punching. Figure 8 (As shown).

[0065] The upper slider 1 continues to move downwards, and the trimming die 12 compacts the flash 13-2 that has been punched off and left on the stripper plate 14 equipped with the floating spring 17. As the upper slider 1 continues to move downwards, the floating spring 17 continues to be compressed. After the punching punch 8 contacts the punching strip 13-1 of the hot forged steel piston skirt 13, it continues to move downwards and completes the punching action under the pressure applied by the upper slider 1. The punching strip 13-1 falls down, and the punching punch 8 will continue to move downwards until the lower slider 1 reaches the set lower stop point.

[0066] Fifth stage, orderly reset ( Figure 9 (As shown).

[0067] After the upper slider 1 reaches its lower stop, it begins to return to its original position. At this time, the floating spring 17 extends, pushing against the stripper plate 14 with the punched flash 13-2, and moves upward along with the trimming die 12, the upper finishing die 10, the punching punch 8, and the upper slider 1. Then, the floating spring 17 returns to its original length, the trimming spring 7 in the spring seat 6 returns to its preload length, and the clamping spring 9 in the upper finishing die 10 returns to its preload length. The upper slider 1 then returns to its upper stop.

[0068] Phase 6, Automated Cleanup ( Figure 10 (As shown).

[0069] After the upper slider 1 returns to its upper stop point, the stripper plate 14, due to the extension of the floating spring 17, ejects the cut-off flash 13-2. The punched strip 13-1 is punched into the hole of the lower die base 20. The operator then sequentially removes the hot-forged steel piston skirt, the punched flash, and the punched strip after ejection.

[0070] As can be seen from the above processing sequence, the main functions of the entire device and system are achieved by three sets of rectangular springs with different rated loads, stiffnesses, and strokes, which work in conjunction with the sequential action of the slide block on the press. The clamping springs act first, clamping the hot forging to pre-tighten, fit, and finely adjust the upper finishing mold cavity to the hot forging. Next, the trimming springs act, providing pre-cutting force. The actual trimming force is provided by the pressure applied by the slide block on the machine. This pre-cutting force makes the cut smoother and reduces burrs. Finally, after punching, the floating springs push out the cut-off flash through the stripper plate, preventing the flash from getting stuck in the lower die.

[0071] The key to the entire device and system lies in the selection of rectangular springs. Other conventional springs, such as cylindrical springs, have poor resistance to eccentric loads, short lifespans, and are prone to thermal failure; nitrogen springs have poor heat resistance and are not suitable for high-temperature hot forging punching environments; disc springs have loose force distribution, are prone to eccentric loads, are inconvenient to assemble, and have poor force transmission consistency during use. Rectangular springs, compared to other conventional springs, have better stiffness, more uniform force distribution, better consistency, a certain degree of correction capability, and higher heat resistance, enabling them to be used in hot forging correction working environments.

[0072] In addition to the four guide pillars in the spring seat that serve as guides, the entire device and system also has four separate guide pillars 3 and guide sleeves 4 around the mold to assist in guiding the entire system and ensure the accuracy of the guidance.

[0073] The core working principle of this device lies in "spring-coordinated control of process timing + thermal flexible constraint", and its innovation is reflected in the following three aspects:

[0074] ① Differentiated selection and synergistic mechanism of rectangular springs

[0075] In response to the high temperature and off-center load characteristics of hot forging environments, this patent abandons the limitation of "single spring type" in existing technologies and innovatively selects rectangular springs. By matching the parameters of three sets of springs, it achieves an orderly connection of "clamping-trimming-punching-resetting"—the flexible force of the clamping spring ensures finishing accuracy, the progressive pre-cutting force of the trimming spring controls deformation, and the buffering force of the floating spring achieves smooth material removal. The synergistic effect of the three solves the technical problem in this field that "a single spring cannot meet the needs of multiple processes".

[0076] ② Technological innovation of "edge trimming followed by punching + simultaneous finishing"

[0077] Traditional processes, where the order of "punching before trimming" or "trimming before punching," can cause forgings or flash to get stuck on the die due to tooling constraints. This necessitates the design of an additional stripping mechanism, increasing structural complexity and the risk of failure. This patent addresses this by adjusting and optimizing the process sequence design, adding a finishing process: trimming removes flash constraints first, then punching prevents forgings from getting stuck on the die. Simultaneously, the continuous pressure of a clamping spring synchronizes finishing with trimming / punching. This logic not only simplifies the structure (eliminating the need for an additional stripping mechanism) but also fundamentally eliminates "precision loss from secondary clamping," significantly improving machining accuracy. This represents a significant improvement over existing hot forging punching processes.

[0078] ③ Precision assurance system of double guide post and guide sleeve and hot positioning

[0079] To ensure the positioning of forgings under hot conditions, a U-shaped boss is designed on the punching skin for auxiliary positioning, and precise positioning is achieved through the circumference of the lower mold cavity. Simultaneously, the positioning is further ensured by the four guide pillars and bushings of the mold frame, thus achieving precise control of the entire positioning system. This system avoids the problem of "hot-state guiding accuracy attenuation" in traditional single positioning devices, ensuring the long-term stability of the composite punching device.

[0080] The core innovations of this invention and a description of its novelty, inventiveness, and utility:

[0081] ① Novelty: Technical features not disclosed in the prior art

[0082] This patent is the first to propose applying "three sets of rectangular springs with differentiated parameters" to the "edge trimming-punching-finishing" composite processing of hot-forged steel piston skirts. The combined structure of "U-shaped punched boss positioning + double guide post and guide sleeve" is not disclosed in any publicly available hot forging processing equipment, and its positioning and guiding accuracy are superior to existing technologies. The process logic of "edge trimming followed by punching + simultaneous finishing" breaks through the limitations of traditional step-by-step processing. Some existing patents only achieve "edge trimming and punching composite" without involving simultaneous finishing; this patent has a higher degree of process integration.

[0083] ②Inventiveness: Not obvious to a person skilled in the art

[0084] Addressing the pain point of "hot deformation," this patent does not adopt the conventional approach of "increasing equipment tonnage." Instead, it employs an innovative solution of "rectangular spring flexible clamping + synchronous finishing," solving the problem from the perspective of "force control" rather than "force resistance." This technical approach is not readily apparent. The parameters of the rectangular spring (stiffness, load, stroke) need to be determined comprehensively by considering the hot mechanical properties of the hot forging, punching force calculations, and the thermal expansion coefficient of the die. This involves multiple disciplines, including materials science, mechanics, and hot working processes, and cannot be obtained by those skilled in the art through conventional experiments. The gap compensation design between the double guide post and guide sleeve and the hot positioning requires precise calculation of the thermal expansion difference between the die and the forging. Existing technologies often neglect the influence of hot conditions. The design details of this patent demonstrate a deep understanding of the hot working environment and possess inventiveness.

[0085] ③ Practicality: It can be widely applied and has significant benefits.

[0086] The device has a simple structure, and the core components (rectangular spring, guide post and guide sleeve, mold) are all standard or easy-to-process parts. The manufacturing cost is lower than that of traditional tooling, and it can be quickly promoted.

Claims

1. A three-in-one device for edge trimming, punching, and finishing of hot-forged steel piston skirts to suppress thermal deformation, comprising an upper slide block and an upper die holder connected to each other, and a lower slide block and a lower die holder connected to each other, wherein the upper die holder and the lower die holder are arranged facing each other, characterized in that, Also includes: The spring seat has a clamping spring guide post in the middle, on which a clamping spring is fitted; the spring seat has slit spring guide posts around its perimeter, on which slit springs are fitted; the top of the slit spring guide post is fixed to the upper mold base, and the bottom extends out of the outer side of the spring seat and is provided with a locking bolt; the spring seat is installed below the upper mold base through the slit spring guide posts, and a certain gap is left between the spring seat and the upper mold base. The upper finishing mold is installed in the middle of the spring seat, and its top is connected to the bottom of the clamping spring; The trimming die is installed in the middle of the spring seat and is located on the outer periphery of the bottom end face of the upper finishing die; The lower die, installed on top of the lower die base, is used to support the piston skirt of the hot forged steel to be processed; The stripper plate, which is ring-shaped, is placed on the outer periphery of the top end face of the lower die, and its vertical direction corresponds to the trimming die; the bottom of the stripper plate is connected to the lower die base by a floating spring, and the floating spring has a spring column inside.

2. The three-in-one device for suppressing hot-deformation hot-forged steel piston skirt trimming, punching, and finishing as described in claim 1, characterized in that, The shearing spring, clamping spring, and floating spring are all rectangular springs.

3. The three-in-one device for suppressing hot-deformation hot-forged steel piston skirt trimming, punching, and finishing as described in claim 1, characterized in that, The punched skin of the hot-forged steel piston skirt to be processed has a U-shaped boss, and a U-shaped hole groove for auxiliary positioning is provided at the corresponding position in the lower mold cavity to achieve precise positioning between the hot-forged steel piston skirt and the lower mold.

4. The processing method of the three-in-one device for suppressing hot deformation of hot forged steel piston skirts—edge trimming, punching, and finishing—as described in claim 1, characterized in that, The steps are as follows: The first stage is the positioning of the hot forging reference. With the mold frame open, the piston skirt is positioned on the lower mold by the square punched holes and the bottom boss of the hot forged steel piston skirt. The second stage involves thermal flexible clamping; The upper finishing die, punch, and trimming die connected to the upper slider begin to move downward with the upper die base; the upper finishing die first contacts the hot forged steel piston skirt and hugs the skirt tightly; The third stage is pre-cutting and simultaneous finishing. As the upper slider continues to move downwards, the cutting edge of the trimming die begins to contact the flash of the hot-forged steel piston skirt. Due to the increasing elasticity of the trimming spring, the cutting edge of the trimming die gradually increases the punching force until the spring seat with the trimming spring guide post contacts the upper die seat of the die set. When the punching force of the trimming die becomes the pressure applied by the slider on the equipment, the flash of the hot-forged steel piston skirt is cut off and pressed by the trimming die onto the stripper plate with the floating spring. At the same time, the hot-forged steel piston skirt is placed and fixed on the lower die. After the upper finishing die holds the hot-forged steel piston skirt tightly, it cannot move downwards and can only compress the upper holding spring. Under the action of the holding spring, the cavity position, thin skirt position, and thick skirt position of the hot-forged steel piston skirt are finished. The punching punch connected to the fixed block moves downwards with the upper slider and gradually contacts the position where the punching skin of the hot-forged steel piston skirt is located. The fourth stage is high-precision punching; The upper slider continues to move downwards, and the cutting die compacts the flash left on the stripper plate equipped with the floating spring. As the upper slider continues to move downwards, it continues to compress the floating spring. After the punching punch contacts the punching strip of the hot forged steel piston skirt, it continues to move downwards and completes the punching action under the pressure applied by the upper slider. The punching strip falls down, and the punching punch will continue to move downwards until the lower slider reaches the set lower stop point. The fifth stage is orderly reset; After the upper slider reaches the lower stop point, it begins to reset upwards. At this time, the floating spring extends, pushing the stripper plate with the punched flash upwards along with the trimming die, the upper finishing die, the punching punch, and the upper slider. Then, the floating spring returns to its own length, the trimming spring in the spring seat returns to its preload length, and the clamping spring in the upper finishing die returns to its preload length. The upper slider returns to the upper stop point. The sixth stage is automated cleanup; After the upper slider returns to the upper stop point, the stripper plate returns to its extended state due to the floating spring, pushing out the cut-off flash; the punched strip is punched into the hole of the lower die base; the operator sequentially clamps away the hot forged steel piston skirt, the punched flash, and the punched strip after punching.

Images