A piston pin machining device and process

Abstract

The application provides a piston pin processing device and process, and relates to the technical field of internal combustion engine piston pins. The piston pin processing device comprises an upper die plate, an upper die seat, an upper punch pressure bearing, an upper punch, a light extrusion cutter, a lower die plate, a lower die seat, a lower punch pressure bearing, a return cutter bin and a concave die. When the upper die plate and the lower die plate are close to each other, the light extrusion cutter first passes through the inner hole of the piston pin in the limiting port of the concave die, and then falls into the hollow cavity of the return cutter bin after sequentially passing through the return cutter port and the feed port. The piston pin processing device and process can perform light extrusion processing on the inner hole of the piston pin through the light extrusion cutter after the rough boring of the inner hole of the piston pin is completed, the surface roughness of the inner hole of the piston pin after the light extrusion processing is low, the processing quality is significantly improved, and the cracking failure of the inner hole surface is prevented. The light extrusion process is simple to operate and low in processing difficulty, and the processing efficiency of the inner hole of the piston pin is effectively improved.

Description

Technical Field

[0001] This invention relates to the field of piston pin technology for internal combustion engines, and more specifically to a piston pin processing device and process. Background Technology

[0002] With the continuous upgrading of national emission regulations and the increasing market demand for internal combustion engine power, high-performance diesel engines with high power density have become one of the important development directions in the internal combustion engine industry. The increasing performance of diesel engines is specifically reflected in the continuous increase in combustion pressure and power output per liter, which in turn increases the mechanical and thermal loads on the engine, posing a significant challenge to the reliability of components. The piston pin, as a key component connecting the piston and connecting rod, transmits the pressure generated by the combustion expansion of the fuel-air mixture on the piston to the connecting rod, realizing the engine power output through the crankshaft and flywheel. During engine operation, the piston pin endures high temperature, high pressure, and alternating loads in a very harsh working environment. Therefore, the structural design, strength, performance, and machining precision of the piston pin have a significant impact on the reliability and service life of the entire engine.

[0003] The manufacturing of diesel engine piston pins mainly consists of three parts: blank manufacturing, machining, and heat treatment. The inner bore of the piston pin is typically completed through drilling, rough boring, and fine boring in sequence. Because the annealed hardness of the piston pin raw material is relatively low, iron filings are difficult to break during boring, easily scratching the inner bore surface. The inner bore of the piston pin is generally small, and a long boring bar is required to machine the entire inner bore. Due to the large length-to-diameter ratio of the boring bar, severe vibration marks are easily generated in the inner bore during boring. If the boring bar is rotated during machining, misalignment during secondary clamping is very likely, resulting in obvious tool marks in the inner bore. All of these factors lead to substandard quality of the piston pin inner bore. Furthermore, boring requires both rough boring and fine boring processes, making machining difficult, time-consuming for a single piston pin, and requiring frequent tool changes. The high surface roughness of the inner bore easily leads to high internal stress, making it highly susceptible to fatigue fracture failure during operation. Summary of the Invention

[0004] The purpose of this invention is to provide a piston pin processing device and process, which sequentially employs rough boring and extrusion finishing processes to improve the processing efficiency and surface quality of the piston pin inner hole.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A piston pin processing device includes an upper template, an upper die base, an upper punch bearing component, an upper punch, an extrusion cutter, a lower template, a lower die base, a lower punch bearing component, a return die chamber, and a die cavity;

[0007] The upper mold base is provided at the lower end of the upper template. The lower end of the upper mold base is connected to the upper punch via the upper punch bearing member. The upper punch is arranged in a vertical direction. The end of the upper punch is detachably connected to the extrusion knife.

[0008] The lower template is located below the upper template, and the lower mold base is provided at the upper end of the lower template. The upper end of the lower mold base is connected to the return chamber and the die from bottom to top via the lower punch bearing member.

[0009] The upper end face of the die has a limiting opening along the vertical direction for holding the piston pin and limiting the piston pin. The lower end face of the die has a return cutting opening along the vertical direction for the extrusion knife to pass through. The return cutting opening is connected to the limiting opening. A support platform for supporting the piston pin is set between the edge of the return cutting opening and the edge of the limiting opening.

[0010] The interior of the return chamber is a hollow cavity, and the upper end of the return chamber has an inlet port that communicates with the hollow cavity. The inlet port is connected to the return port.

[0011] When the upper and lower templates approach each other, the calendering knife first passes through the inner hole of the piston pin in the die limiting opening, and then passes through the return and inlet openings in sequence before falling into the hollow cavity of the return chamber.

[0012] Preferably, it further includes a lifting seat and an ejector pin. The lifting seat is slidably connected to the lower punch bearing member in the vertical direction. The ejector pin is provided on the lifting seat. The ejector pin is arranged in the vertical direction. The ejector pin slides through the return chamber and the die in sequence. The end of the ejector pin can abut against the lower end face of the piston pin.

[0013] Preferably, a first guide post is provided on the lower punch bearing member along the vertical direction, and a guide hole is opened on the lifting seat along the vertical direction, with the first guide post cooperating with the guide hole.

[0014] Preferably, it also includes a push rod that slides through the lower punch bearing member, and the end of the push rod can abut against the lower end face of the lifting seat.

[0015] Preferably, the upper punch bearing component includes an upper bearing plate, an upper pad, and a punch seat arranged sequentially from top to bottom on the upper die base. The upper end face of the upper bearing plate abuts against the upper die plate, and the lower end of the punch seat is connected to the upper punch.

[0016] Preferably, the upper punch bearing component further includes a seat sleeve disposed on the upper die holder, and the punch holder is nested inside the seat sleeve.

[0017] Preferably, the lower punch bearing component includes a lower bearing seat, a lower pad sleeve, and a support sleeve arranged sequentially from bottom to top on the lower die base. The lower end face of the lower bearing seat abuts against the lower die plate, and the upper end of the support sleeve is connected to the return blade chamber.

[0018] Preferably, it further includes a guide sleeve and a guide post. The guide sleeve is disposed on the upper mold base and is arranged in a vertical direction. The guide post is disposed on the lower mold base and is arranged in a vertical direction. The guide post is slidably fitted inside the guide sleeve.

[0019] Preferably, a tool outlet communicating with the hollow cavity is provided on one side of the return tool chamber.

[0020] A piston pin machining process, using the aforementioned piston pin machining apparatus, includes the following steps:

[0021] Step 1: Place the piston pin, whose inner hole has been rough-bored, into the die limiting opening;

[0022] Step 2: The upper and lower templates are brought closer together at a set distance so that the tip of the extrusion knife abuts against the upper end of the inner hole of the piston pin;

[0023] Step 3: The upper and lower templates continue to move closer to each other. The calendering knife first passes through the inner hole of the piston pin, and then passes through the return and inlet ports in sequence before falling into the hollow cavity of the return chamber.

[0024] Step 4: The upper and lower mold plates move away from each other and reset. The lifting seat moves upward under the action of external force, and the ejector pin pushes out the piston pin in the cavity of the die.

[0025] The beneficial technical effects of this invention are:

[0026] After rough boring of the inner hole of the piston pin, the piston pin processing device and process of the present invention are applied to perform extrusion processing by passing an extrusion cutter through the inner hole of the piston pin on the basis of rough boring. The surface roughness of the inner hole of the piston pin after extrusion processing is low, the processing quality is significantly improved, and cracking failure of the inner hole surface is prevented. The whole extrusion process is simple to operate and has low processing difficulty, which effectively improves the processing efficiency of the inner hole of the piston pin. Attached Figure Description

[0027] Figure 1 This is a cross-sectional view of the piston pin processing device according to an embodiment of the present invention;

[0028] Figure 2 This is a cross-sectional view of the die cavity in the piston pin processing device according to an embodiment of the present invention. Detailed Implementation

[0029] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. Certain embodiments of the invention will be described more fully below with reference to the accompanying drawings, and some, but not all, of these embodiments will be shown. In fact, various embodiments of the invention can be implemented in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided to enable the invention to meet applicable legal requirements.

[0030] In the description of this invention, it should be noted that the terms "inner," "outer," "upper," "lower," "front," and "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for 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. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0031] In this embodiment of the invention, a piston pin processing device and process are provided. Please refer to [reference needed]. Figure 1 , Figure 2 As shown.

[0032] A piston pin processing device includes an upper template 11, an upper die base 12, an upper punch bearing component, an upper punch 13, an extrusion cutter 2, a lower template 31, a lower die base 32, a lower punch bearing component, a return die chamber 33, and a die 34.

[0033] An upper die holder 12 is provided at the lower end of the upper die holder 11. The lower end of the upper die holder 12 is connected to the upper punch 13 via an upper punch bearing member. The upper punch 13 is arranged vertically, and the end of the upper punch 13 is detachably connected to the extrusion cutter 2. The end of the upper punch 13 is provided with a limiting pin, and the upper end of the extrusion cutter 2 is provided with a limiting hole. The limiting pin is inserted into the limiting hole to achieve a detachable connection between the end of the upper punch 13 and the extrusion cutter 2. After the extrusion cutter 2 passes through the inner hole of the piston pin 4, the extrusion cutter 2 falls into the hollow cavity of the return cutter chamber 33 under its own gravity.

[0034] The lower template 31 is located below the upper template 11. The upper end of the lower template 31 is provided with a lower mold base 32. The upper end of the lower mold base 32 is connected to the return chamber 33 and the die 34 from bottom to top via the lower punch bearing member.

[0035] A limiting opening 341 is formed on the upper end face of the die 34 along the vertical direction. The limiting opening 341 is used to hold the piston pin 4 and limit its position. A return cutting edge 342 is formed on the lower end face of the die 34 along the vertical direction. The return cutting edge 342 is used for the extrusion cutter 2 to pass through the inner hole of the piston pin 4. The return cutting edge 342 and the limiting opening 341 are arranged coaxially and communicate with each other. A support platform 343 is set between the edge of the return cutting edge 342 and the edge of the limiting opening 341. The support platform 343 is used to support the piston pin 4.

[0036] The interior of the return chamber 33 is a hollow cavity. The upper end of the return chamber 33 has an inlet port that communicates with the hollow cavity. The inlet port is connected to the return port 342.

[0037] The upper template 11 is used to connect to hydraulic equipment, which drives the upper template 11 to move closer to or away from the lower template 31.

[0038] When the upper template 11 and the lower template 31 approach each other, the extrusion cutter 2 first passes through the inner hole of the piston pin 4 in the limiting port 341 of the die 34, and then the extrusion cutter 2 passes through the return cutter port 342 and the inlet cutter port in sequence before falling into the hollow cavity of the return cutter chamber 33.

[0039] The bottom surface of the hollow cavity of the return chamber 33 is inclined, and a knife outlet communicating with the hollow cavity is opened on one side of the return chamber 33. The knife outlet is located at the lower end of the inclined surface. After the extrusion knife 2 falls into the hollow cavity of the return chamber 33, it slides down the inclined surface to the knife outlet to facilitate the recycling of the extrusion knife 2.

[0040] The upper punch bearing component is mounted on the upper die base 12. The upper punch bearing component includes an upper pressure plate 51, an upper pad 52, and a punch seat 53 arranged sequentially from top to bottom. The upper end face of the upper pressure plate 51 abuts against the upper die plate 11. An assembly groove is formed at the lower end of the punch seat 53, and the upper end of the upper punch 13 fits into the assembly groove. The upper end face of the upper pressure plate 51 abuts against the upper die plate 11, so that the force applied by the upper die plate 11 is transmitted directly to the upper punch 13 and the extrusion cutter 2 through the upper pressure plate 51, the upper pad 52, and the punch seat 53.

[0041] The upper mold base 12 has a stepped upper assembly slot on its upper end face, which extends through the upper mold base 12. An upper pressure plate 51 is mounted on the upper end of the upper assembly slot, abutting against the step of the slot. The punch seat 53 is located on the lower end face of the upper mold base 12. The upper pressure plate 51, upper pad 52, and punch seat 53 are connected by multiple bolts. By adjusting the tightness of the bolts, the orientation of the punch seat 53 can be finely adjusted, ensuring it is arranged vertically. The upper pad 52 is a consumable part and can be replaced after long-term use and deformation due to compression.

[0042] The upper punch bearing component also includes a seat 54 disposed on the upper die holder 12, and the punch holder 53 is nested inside the seat 54. The seat 54 limits the punch holder 53, so that the punch holder 53 is arranged in the vertical direction, thereby making the extrusion cutter 2 and the inner hole of the piston pin 4 coaxially arranged.

[0043] The lower punch bearing component is set on the lower die base 32. The lower punch bearing component includes a lower bearing seat 61, a lower pad sleeve 62 and a support sleeve 63 arranged in sequence from bottom to top. The lower end face of the lower bearing seat 61 abuts against the lower die plate 31, and the upper end of the support sleeve 63 is connected to the return chamber 33 via the return chamber pad plate 64.

[0044] The lower die base 32 has a stepped lower assembly slot on its lower end face, which extends through the lower die base 32. A lower pressure bearing seat 61 is mounted on the lower end of the lower assembly slot, abutting against the step of the lower assembly slot. A lower pad sleeve 62 and a support sleeve 63 are nested sequentially within the lower assembly slot. The lower pressure bearing seat 61, lower pad sleeve 62, and support sleeve 63 are connected by multiple bolts. By adjusting the tightness of the bolts, the orientation of the support sleeve 63 can be finely adjusted, thereby ensuring that the inner hole of the piston pin 4 on the die 34 is coaxially arranged with the extrusion cutter 2.

[0045] The lifting seat 71 slides vertically to connect with the lower punch bearing component. The upper end of the lower bearing seat 61 has a first guide post 72 arranged vertically. The lifting seat 71 has a guide hole in the vertical direction, and the first guide post 72 mates with the guide hole. Four ejector pins 73 are arranged vertically at the upper end of the lifting seat 71. The ejector pins 73 slide sequentially through the return die 33 and the die cavity 34, and the ends of the ejector pins 73 abut against the lower end face of the piston pin 4. The lifting seat 71 slides upward along the first guide post 72 to drive the ejector pins 73 to lift the piston pin 4, pushing the piston pin 4 out of the limiting port 341.

[0046] The first guide column 72 and the lifting seat 71 are both located inside the support sleeve 63 to make the overall structure of the device more compact.

[0047] The push rod 74 first slides through the lower template 31, then through the lower punch bearing member (lower bearing seat 61), and the end of the push rod 74 can abut against the lower end face of the lifting seat 71. The push rod 74 is moved upward to drive the lifting seat 71 to slide upward along the first guide post 72.

[0048] An upper assembly cylinder is provided on the lower end face of the upper die holder 12. The guide sleeve 81 is limited and assembled into the upper assembly cylinder by the upper stop block 91. The guide sleeve 81 is arranged vertically. A lower assembly cylinder is provided on the upper end face of the lower die holder 32. The guide post 82 is limited and assembled into the lower assembly cylinder by the lower stop block 92. The guide post 82 is arranged vertically and slidably fitted into the guide sleeve 81. Through the sliding fit between the guide post 82 and the guide sleeve 81, the upper and lower die plates are guided to move closer to each other, improving the alignment accuracy between the extrusion cutter 2 and the inner hole of the piston pin 4.

[0049] A piston pin machining process, using the piston pin machining apparatus described in this embodiment, includes the following steps:

[0050] Step 1: Place the piston pin 4, whose inner hole has been rough-bored, into the limiting opening 341 of the die cavity 34;

[0051] Step 2: The upper template 11 and the lower template 31 are brought closer to each other by a set distance, so that the cutting head of the extrusion knife 2 abuts against the upper end of the inner hole of the piston pin 4;

[0052] Step 3: The upper template 11 and the lower template 31 continue to approach each other. The calendering knife 2 first passes through the inner hole of the piston pin 4, and then the calendering knife 2 passes through the return knife port 342 and the inlet knife port in sequence before falling into the hollow cavity of the return knife chamber 33.

[0053] Step 4: The upper template 11 and the lower template 31 move away from each other and reset. The lifting seat 71 moves upward under the push of the push rod 74, and the ejector pin 73 pushes out the piston pin 4 in the limiting port 341 of the die 34.

[0054] The present invention has been described in detail above with reference to the accompanying drawings. Based on the above description, those skilled in the art should have a clear understanding of the piston pin processing apparatus and process of the present invention. In the piston pin processing apparatus and process of the present invention, after rough boring of the inner hole of the piston pin, a finishing cutter 2 is used to perform finishing by passing through the inner hole of the piston pin 4. The surface roughness of the inner hole of the piston pin 4 after finishing is low, the processing quality is significantly improved, and cracking failure of the inner hole surface is prevented. The entire finishing process is simple to operate, has low processing difficulty, and effectively improves the processing efficiency of the inner hole of the piston pin 4.

[0055] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A piston pin processing device, characterized in that: It includes an upper template, an upper die base, an upper punch bearing component, an upper punch, an extrusion cutter, a lower template, a lower die base, a lower punch bearing component, a return die, a die cavity, an ejector seat, and ejector pins; The upper mold base is provided at the lower end of the upper template. The lower end of the upper mold base is connected to the upper punch via the upper punch bearing member. The upper punch is arranged in a vertical direction. The end of the upper punch is detachably connected to the extrusion knife. The upper punch bearing component includes an upper bearing plate, an upper pad, and a punch seat arranged sequentially from top to bottom on the upper die base. The upper end face of the upper bearing plate abuts against the upper die plate, and the lower end of the punch seat is connected to the upper punch. The upper end face of the upper mold base has a stepped upper assembly slot that runs through the upper mold base. The upper bearing plate is assembled at the upper end of the upper assembly slot and abuts against the step of the upper assembly slot. The punch seat is located at the lower end face of the upper mold base. The upper bearing plate, the upper pad, and the punch seat are connected by multiple bolts. By adjusting the tightness of the bolts, the orientation of the punch seat can be finely adjusted so that the punch seat is arranged in a vertical direction. The lower template is located below the upper template, and the lower mold base is provided at the upper end of the lower template. The upper end of the lower mold base is connected to the return chamber and the die from bottom to top via the lower punch bearing member. The lower punch bearing component includes a lower bearing seat, a lower pad sleeve, and a support sleeve arranged sequentially from bottom to top on the lower die base. The lower end face of the lower bearing seat abuts against the lower die plate, and the upper end of the support sleeve is connected to the return blade chamber. The lower end face of the lower die base has a stepped lower assembly slot that passes through the lower die base. The lower bearing seat is assembled at the lower end of the lower assembly slot and abuts against the step of the lower assembly slot. The lower pad and the support sleeve are nested in the lower assembly slot in sequence. The lower bearing seat, the lower pad and the support sleeve are connected by multiple bolts. By adjusting the tightness of the bolts, the orientation of the support sleeve can be finely adjusted, so that the inner hole of the piston pin on the die is arranged coaxially with the extrusion cutter. The upper end face of the die has a limiting opening along the vertical direction for holding the piston pin and limiting the piston pin. The lower end face of the die has a return cutting opening along the vertical direction for the extrusion knife to pass through. The return cutting opening is connected to the limiting opening. A support platform for supporting the piston pin is set between the edge of the return cutting opening and the edge of the limiting opening. The interior of the return chamber is a hollow cavity, and the upper end of the return chamber has an inlet port that communicates with the hollow cavity. The inlet port is connected to the return port. When the upper template and the lower template approach each other, the calendering knife first passes through the inner hole of the piston pin in the die limiting opening, and then passes through the return knife opening and the inlet opening in sequence before falling into the hollow cavity of the return knife chamber. The lifting seat is slidably connected to the lower punch bearing component in the vertical direction. The lifting seat is provided with the ejector pin, which is arranged in the vertical direction. The ejector pin slides through the return chamber and the die in sequence, and the end of the ejector pin can abut against the lower end face of the piston pin.

2. The piston pin processing device according to claim 1, characterized in that: The lower punch bearing component is provided with a first guide post along the vertical direction, and the lifting seat is provided with a guide hole along the vertical direction, with the first guide post cooperating with the guide hole.

3. A piston pin processing device according to claim 1 or 2, characterized in that: It also includes a push rod that slides through the lower punch bearing member, and the end of the push rod can abut against the lower end face of the lifting seat.

4. The piston pin processing device according to claim 1, characterized in that: The upper punch bearing component also includes a seat sleeve disposed on the upper die holder, and the punch holder is nested inside the seat sleeve.

5. The piston pin processing device according to claim 1, characterized in that: It also includes a guide sleeve and a guide post. The guide sleeve is disposed on the upper mold base and is arranged in a vertical direction. The guide post is disposed on the lower mold base and is arranged in a vertical direction. The guide post is slidably fitted inside the guide sleeve.

6. The piston pin processing device according to claim 1, characterized in that: The return chamber has a cutter outlet on one side that communicates with the hollow cavity.

7. A piston pin machining process, using the piston pin machining apparatus according to any one of claims 1 to 6, characterized in that, Includes the following steps: Step 1: Place the piston pin, whose inner hole has been rough-bored, into the die limiting opening; Step 2: The upper and lower templates are brought closer together at a set distance so that the tip of the extrusion knife abuts against the upper end of the inner hole of the piston pin; Step 3: The upper and lower templates continue to move closer to each other. The calendering knife first passes through the inner hole of the piston pin, and then passes through the return and inlet ports in sequence before falling into the hollow cavity of the return chamber. Step 4: The upper and lower mold plates move away from each other and reset. The lifting seat moves upward under the action of external force, and the ejector pin pushes out the piston pin in the cavity of the die.

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