Double-wedge self-balancing type connecting rod processing equipment

Abstract

The application discloses a double-wedge self-balancing type connecting rod processing equipment and relates to the technical field of connecting rod manufacturing. The connecting rod processing equipment comprises an expansion and breaking mechanism which can be matched with a big-end hole of a connecting rod and comprises a fixed block and an expansion and breaking block. The movable expansion and breaking block is used as a basic carrier, first and second inclined guide surfaces in a converging mode are arranged on opposite end surfaces of the fixed block and the movable expansion and breaking block, and a symmetrical triangular structure is formed. On this basis, independent first and second pressing blocks are equipped and are matched with the first and second inclined guide surfaces in a wedge mode. Double-rod executing elements are used as power sources for realizing synchronous reverse movement of the first and second pressing blocks. Therefore, lateral overturning components generated by the first and second pressing blocks are completely offset through symmetrical double-wedge matching, only radial expansion components are reserved and effectively superposed, micro deflection of the expansion and breaking block is avoided from the stress source, it is ensured that the radial expansion force is always coincident with the central axis and the direction is stable and does not deviate, and therefore, the flatness of a fracture surface and the expansion and breaking quality of the connecting rod are improved.

Description

Technical Field

[0001] This invention relates to the field of connecting rod manufacturing technology, and in particular to a double-wedge self-balancing connecting rod processing equipment. Background Technology

[0002] The fracture expansion process is a key technology in the current manufacturing of high-performance connecting rods. Existing connecting rod fracture expansion technology typically involves laser-machining two symmetrical pre-fabricated crack grooves inside the big end bore of the connecting rod, fitting the big end bore into the moving and stationary sleeve assembly, and engaging the small end bore of the connecting rod with the moving mechanism. A clamping mechanism then presses against the bolt support surfaces on both sides of the big end bore of the connecting rod.

[0003] During operation, the wedge-shaped engagement between the tie rod and the moving and fixed sleeves applies a force in the same direction as the clamping mechanism to the moving and fixed sleeves. This, in conjunction with the moving mechanism, drives the expansion block to move, thereby applying a radial expansion force perpendicular to the crack groove to the connecting rod big end hole. This causes the crack to start at the root of the precast groove and expand along a preset path, achieving the separation of the connecting rod body and the connecting rod cap along the fracture surface under low plastic deformation.

[0004] However, in the existing structure, the tie rod and the moving and fixed sleeves use a single-sloping wedge-shaped fit to transmit the expansion force. During the radial expansion of the moving and fixed sleeves, the wedge-shaped slope will generate a lateral component force on the moving and fixed sleeves, causing the moving and fixed sleeves to bear an additional overturning moment. This can easily cause the expansion block to deflect slightly, and the radial expansion force direction will deviate from the central axis, thereby affecting the flatness of the fracture surface and reducing the expansion quality of the connecting rod. Summary of the Invention

[0005] The purpose of this invention is to solve the problem that existing connecting rod fracture technology, due to the lateral force and additional overturning moment generated by the single-sloping wedge fit, easily leads to slight deflection of the fracture block, resulting in poor flatness of the fracture surface.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a double-wedge self-balancing connecting rod processing equipment, comprising a base, a clamping mechanism disposed on the base, and a fracture mechanism capable of engaging with the big end hole of the connecting rod.

[0007] The clamping mechanism has a top rod that abuts against the bolt support surfaces on both sides of the big end of the connecting rod, and the expansion mechanism includes a fixed block fixed to the base and an expansion block that can move relative to the fixed block.

[0008] The opposite end faces of the expansion block and the fixed block are respectively provided with a first inclined guide surface and a second inclined guide surface that are inclined towards each other and intersect, forming a convex triangular structure together.

[0009] A first pressing block and a second pressing block are provided between the fixed block and the expansion block. The first pressing block and the first inclined guide surface, as well as the second pressing block and the second inclined guide surface, are wedge-shaped fits.

[0010] The dual-bar actuator on the base is used to drive the first pressure block and the second pressure block to move synchronously in opposite directions, so that the radial components of the forces acting on the fracture block by the first pressure block and the second pressure block are superimposed in the same direction and cancel each other out of the lateral components acting on the fracture block. This drives the fracture block to expand radially outward without additional overturning moment, causing the connecting rod big end hole to fracture along a preset fracture path.

[0011] In the above technical solution, before the expansion fracture, the connecting rod big end hole is fitted onto the outside of the expansion fracture mechanism, and the top rod of the clamping mechanism abuts against the bolt support surfaces on both sides of the connecting rod big end. The top rod applies a stable axial clamping force to the connecting rod to ensure that the connecting rod does not move or deviate during the entire expansion fracture process.

[0012] When the work begins, the double-bar actuator fixed to the base is activated, driving the first pressure block and the second pressure block to move synchronously in opposite directions along the installation space between the fixed block and the expansion joint. The first pressure block slides in a wedge shape along the first inclined guide surface formed by the fixed block and the expansion joint, and the second pressure block slides in a wedge shape along the second inclined guide surface.

[0013] During the downward movement of the first pressure block, its inclined surface acts on the first inclined guide surface between the fixed block and the fracture block, generating a downward thrust. Since the fixed block remains stationary, this thrust forces the fracture block to move outward through the wedge-shaped mating surface. Similarly, during the upward movement of the second pressure block, its inclined surface acts on the second inclined guide surface, generating an upward thrust, which also forces the same fracture block to move outward through the wedge-shaped mating surface. At this time, the lateral components of the forces exerted by the first and second pressure blocks on the fracture block in the vertical direction are equal in magnitude and opposite in direction, thus canceling each other out. Simultaneously, the radial components of these two forces in the horizontal direction are in the same direction, superimposing to form a purely radial outward expansion resultant force.

[0014] Driven by this pure radial expansion force, the fracture block moves smoothly outward only along the predetermined radial direction, making it difficult to produce any slight deflection or overturning. As the stroke of the dual-bar actuator increases, the first and second pressure blocks continue to move towards each other. Through the wedge-shaped amplification effect of the first and second inclined guide surfaces, the radial expansion force output by the fracture block continues to increase and acts uniformly on the inner wall of the connecting rod big end bore. When the expansion stress exceeds the material fracture strength at the root of the pre-made crack groove inside the connecting rod big end bore, the crack initiates at the root of the groove and steadily propagates along the preset fracture path, ultimately causing the connecting rod cap and connecting rod body to separate symmetrically along the crack groove under low plastic deformation.

[0015] After the expansion is completed, the dual-rod actuators reverse their actions, driving the first and second pressure blocks to reset in the opposite direction, releasing the pressure on the first and second inclined guide surfaces. At this time, the expansion block can be retracted with the help of external force, thus facilitating the removal of the separated connecting rod body and connecting rod cap, completing one working cycle.

[0016] The beneficial effects of this invention are: First, because the lateral forces exerted by the first and second pressure blocks on the fracture block are equal in magnitude, opposite in direction, and act along the same line of action, they completely cancel each other out inside the fracture block. Therefore, the fracture block is not subjected to any excess torque during operation, and only bears a pure radial expansion force outward along the predetermined fracture direction. Thus, the simultaneous opposite forces on the double-wedge mating surfaces eliminate the lateral force and additional overturning moment generated by the wedge-shaped inclined surface, preventing slight deflection of the fracture block.

[0017] Second, ensure that the radial expansion force always coincides with the central axis and remains stable in direction, thus ensuring that crack propagation remains highly symmetrical.

[0018] Third, it ensures uniform stress distribution during the forming process of the connecting rod fracture surface, significantly improving the flatness and forming accuracy of the fracture surface.

[0019] Furthermore, in this embodiment of the invention, a moving mechanism is also included, the moving mechanism having a sliding plate that slides with a guide rail on the base, the expansion block being fixed on the sliding plate, and the sliding plate being provided with a positioning part for engaging with the small end hole of the connecting rod.

[0020] Furthermore, in this embodiment of the invention, the dual-rod actuator is a dual-piston rod hydraulic cylinder, which includes a first rod and a second rod capable of synchronously moving in opposite directions. The first rod passes through the central shaft hole of the second pressure block and is fixedly connected to the first pressure block. The second rod is fixedly connected to the second pressure block through a connecting rod.

[0021] Furthermore, in this embodiment of the invention, a sliding bearing bushing is provided in the central shaft hole of the second pressure block, and the first rod body is slidably engaged with the sliding bearing bushing.

[0022] Furthermore, in this embodiment of the invention, the surfaces of the first pressing block, the second pressing block, the first inclined guide surface, and the second inclined guide surface are all prepared with a gradient hardness coating, wherein the hardness of the gradient hardness coating increases in a gradient from its interface with the substrate to the surface layer.

[0023] Furthermore, in this embodiment of the invention, the thermal expansion coefficients of the materials of the first pressure block and the second pressure block are greater than the thermal expansion coefficient of the material of the fracture block, so that when the working temperature rises, the mating gap of the wedge-shaped mating surface is reduced or eliminated.

[0024] Furthermore, in this embodiment of the invention, the first pressing block and the second pressing block are provided with heating elements and equipped with temperature sensors and temperature control modules.

[0025] The temperature control module is used to control the heating element according to the signal collected by the temperature sensor, so as to heat the first pressure block and the second pressure block to a preset temperature before they break.

[0026] Furthermore, in this embodiment of the invention, the temperature control module is a PID controller. The PID controller is used to adjust the heating power of the heating element according to the deviation between the temperature signal collected by the temperature sensor and the preset target temperature value, so as to maintain the constant temperature of the first pressing block and the second pressing block.

[0027] Furthermore, in this embodiment of the invention, the wedge-shaped mating surface between the first pressing block and the first inclined guide surface, and the wedge-shaped mating surface between the second pressing block and the second inclined guide surface are both variable-lift angle curved surfaces, and the lift angle of the variable-lift angle curved surfaces increases monotonically along the movement direction of the first pressing block and the second pressing block.

[0028] Furthermore, in this embodiment of the invention, the variable helix angle surface is a continuous guideable surface, whose helix angle monotonically increases from 5°~7° to 15°~20° along the direction of motion, and the rate of change of the helix angle of adjacent micro-segments does not exceed 3° / mm. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of a double-wedge self-balancing connecting rod processing equipment according to an embodiment of the present invention.

[0030] Figure 2 This is a schematic diagram of the expansion and fracture mechanism according to an embodiment of the present invention.

[0031] Figure 3 This is a schematic diagram of the expansion fracture mechanism according to an embodiment of the present invention.

[0032] Figure 4 This is a schematic diagram of the fixing block and the expansion joint block in an embodiment of the present invention.

[0033] 1. Base; 2. Clamping mechanism; 3. Slide plate; 4. Positioning part; 10. Fracture mechanism; 11. Fixing block; 12. Fracture block; 121. First inclined guide surface; 122. Second inclined guide surface; 13. First pressing block; 14. Second pressing block. 20. Dual-lever actuator. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the present invention clear and complete, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only some, not all, embodiments of the present invention, and are merely illustrative of the embodiments of the present invention. They are not intended to limit the embodiments of the present invention. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] In the description of this invention, it should be noted that the terms "center," "middle," "upper," "lower," "left," "right," "inner," "outer," "top," "bottom," "side," "vertical," and "horizontal," 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 the 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 the invention. Furthermore, the terms "a," "first," "second," "third," "fourth," "fifth," and "sixth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0036] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0037] For purposes of simplicity and illustration, the principles of the embodiments are described primarily by way of example. In the following description, numerous specific details are set forth to provide a thorough understanding of the embodiments. However, it will be apparent to those skilled in the art that these embodiments may not be limited to these specific details in practice. In some instances, the structure of well-known double-wedge self-balancing linkage machining equipment has not been described in detail to avoid unnecessarily obscuring these embodiments. Furthermore, all embodiments can be used in combination with each other.

[0038] It should be noted that the accompanying drawings are part of the content of the instruction manual. The structural shapes, connections, fits, and positional relationships that can be clearly seen in the accompanying drawings should all be understood as part of the content of the instruction manual.

[0039] A double-wedge self-balancing connecting rod processing equipment, such as Figure 1As shown, it includes a base 1, a clamping mechanism 2 provided on the base 1, and a break-off mechanism 10 that can cooperate with the big end hole of the connecting rod.

[0040] The clamping mechanism 2 has a top rod that abuts against the bolt support surfaces on both sides of the big end of the connecting rod, and the expansion and breaking mechanism 10 includes a fixing block 11 fixed to the base 1 and an expansion and breaking block 12 that can move relative to the fixing block 11.

[0041] The clamping mechanism 2 includes a support frame fixed to the base 1 and two sets of force-applying actuators installed on the support frame. The force-applying actuators are preferably existing hydraulic cylinders, and their output rods are push rods. The push rods of the two force-applying actuators can feed towards each other synchronously or retract in opposite directions synchronously to ensure that the clamping force on the bolt support surfaces on both sides of the big end of the connecting rod is always equal in magnitude, opposite in direction, and coaxial.

[0042] like Figure 2 , Figure 3 As shown, the opposite end faces of the expansion joint 12 and the fixed block 11 are respectively provided with a first inclined guide surface 121 and a second inclined guide surface 122 that are inclined towards each other and intersect, forming a convex triangular structure. The vertex of this triangular structure points towards the center of the connecting rod big end hole. The essence of this structural design is to decompose the traditional single force transmission path into two symmetrical force transmission paths.

[0043] like Figure 3 As shown, a first pressing block 13 and a second pressing block 14 are provided between the fixing block 11 and the expansion block 12. The first pressing block 13 and the first inclined guide surface 121 and the second pressing block 14 and the second inclined guide surface 122 are wedge-shaped fits.

[0044] The dual-bar actuator 20 provided on the base 1 is used to drive the first pressure block 13 and the second pressure block 14 to move synchronously in opposite directions, so that the radial component forces of the first pressure block 13 and the second pressure block 14 acting on the fracture block 12 are superimposed in the same direction and cancel each other out of the lateral component forces acting on the fracture block 12. This drives the fracture block 12 to expand radially outward without bearing the radial expansion force and without additional overturning moment, so that the connecting rod big end hole expands and breaks along the preset fracture path. Detailed implementation method:

[0046] Before the fracture, the connecting rod big end hole is fitted onto the outside of the fracture mechanism 10. The top rod of the clamping mechanism 2 presses against the bolt support surfaces on both sides of the connecting rod big end. The top rod applies a stable axial clamping force to the connecting rod to ensure that the connecting rod does not move or shift during the entire fracture process.

[0047] When the work begins, the double-bar actuator 20 fixed to the base 1 is activated, driving the first pressure block 13 and the second pressure block 14 to move synchronously in opposite directions along the installation space between the fixed block 11 and the expansion block 12. The first pressure block 13 slides in a wedge shape along the first inclined guide surface 121 formed by the fixed block 11 and the expansion block 12, and the second pressure block 14 slides in a wedge shape along the second inclined guide surface 122.

[0048] During the downward movement of the first pressure block 13, its inclined surface acts on the first inclined guide surface 121 between the fixed block 11 and the fracture block 12, generating a downward thrust. Since the fixed block 11 remains stationary, this thrust forces the fracture block 12 to move outward through the wedge-shaped mating surface. Similarly, during the upward movement of the second pressure block 14, its inclined surface acts on the second inclined guide surface 122, generating an upward thrust, which also forces the same fracture block 12 to move outward through the wedge-shaped mating surface. At this time, the lateral components of the forces exerted by the first pressure block 13 and the second pressure block 14 on the fracture block 12 in the vertical direction are equal in magnitude and opposite in direction, thus canceling each other out. At the same time, the radial components of these two forces in the horizontal direction are in the same direction, superimposing to form a purely radial outward expansion resultant force.

[0049] Driven by this pure radial expansion force, the fracture block 12 moves smoothly outward only along the predetermined radial direction, making it difficult to produce any slight deflection or overturning. As the stroke of the dual-bar actuator 20 increases, the first pressure block 13 and the second pressure block 14 continue to move towards each other. Through the wedge-shaped amplification effect of the first inclined guide surface 121 and the second inclined guide surface 122, the radial expansion force output by the fracture block 12 continues to increase and acts uniformly on the inner wall of the connecting rod big end hole. When the expansion stress exceeds the material fracture strength at the root of the pre-made crack groove inside the connecting rod big end hole, the crack initiates at the root of the groove and steadily expands along the preset fracture path, ultimately causing the connecting rod cap and the connecting rod body to separate symmetrically along the crack groove under a low plastic deformation state.

[0050] After the expansion is completed, the dual-bar actuator 20 reverses its action, driving the first pressure block 13 and the second pressure block 14 to reset in the opposite direction, releasing the pressure on the first inclined guide surface 121 and the second inclined guide surface 122. At this time, the expansion block 12 can be retracted with the help of external force, so as to facilitate the removal of the separated connecting rod body and connecting rod cap, completing one working cycle.

[0051] The advantages of this invention are that, based on the fixed block 11 and the movable fracture block 12 as the basic carriers, a first inclined guide surface 121 and a second inclined guide surface 122 are arranged on their opposite end faces to form a symmetrical triangular structure. On this basis, independent first pressure blocks 13 and second pressure blocks 14 are equipped to form a wedge-shaped fit with the first inclined guide surface 121 and the second inclined guide surface 122 respectively. A dual-rod actuator 20 is used as the power source to realize the synchronous reverse movement of the first pressure block 13 and the second pressure block 14. Thus, the lateral overturning component force generated by the first pressure block 13 and the second pressure block 14 is completely canceled out through the symmetrical double wedge fit, and only the radial fracture component is retained and effectively superimposed. From the root of the force, the slight deflection of the fracture block 12 is eliminated, ensuring that the radial expansion force always coincides with the central axis and the direction is stable and does not deviate, thereby improving the flatness of the fracture surface and the fracture quality of the connecting rod.

[0052] Preferably, such as Figure 1 As shown, it also includes a moving mechanism, which has a slide plate 3 that slides with the guide rail on the base 1. The expansion block 12 is fixed on the slide plate 3, and the slide plate 3 is provided with a positioning part 4 for engaging with the small end hole of the connecting rod.

[0053] Specifically, before the fracture process begins, the small end hole of the connecting rod to be processed is fitted into the positioning part 4 on the slide plate 3, while the large end hole of the connecting rod is fitted onto the outside of the fracture mechanism 10. When the fracture action is initiated, the fracture block 12 expands outward under the drive of radial expansion force, and the large end hole of the connecting rod fractures and separates along the pre-made crack groove. During this process, the connecting rod cap and the connecting rod body tend to separate relative to each other due to fracture. However, since the small end hole of the connecting rod is fixedly connected to the slide plate 3 through the positioning part 4, and the slide plate 3 is slidably engaged with the base 1 through the guide rail, when the large end hole of the connecting rod fractures and separates, the entire connecting rod body together with the slide plate 3 can move along the direction of the guide rail, maintaining the spatial posture stability of the connecting rod at the moment of fracture. After the fracture is completed, the slide plate 3 returns to its original position, making it easy to remove the separated connecting rod cap and connecting rod body.

[0054] By fixing the positioning part 4 to the slide plate 3 and sliding the slide plate 3 to the guide rail of the base 1, the connecting rod as a whole obtains a passive degree of freedom in the direction of force during the fracture process.

[0055] Preferably, the dual-rod actuator 20 is a dual-piston rod hydraulic cylinder, which includes a first rod and a second rod capable of synchronously moving in opposite directions. The first rod passes through the central shaft hole of the second pressure block 14 and is fixedly connected to the first pressure block 13. The second rod is fixedly connected to the second pressure block 14 through a connecting rod.

[0056] More preferably, a sliding bearing bushing is provided in the central shaft hole of the second pressure block 14, and the first rod body slides in fit with the sliding bearing bushing. The sliding bearing bushing has a cylindrical structure and is fixed in the central shaft hole of the second pressure block 14 by interference fit or adhesive bonding.

[0057] Due to the presence of the sliding bearing bushing, the radial runout of the first rod is effectively constrained, and the axis of motion remains stable.

[0058] Preferably, the surfaces of the first pressing block 13, the second pressing block 14, the first inclined guide surface 121 and the second inclined guide surface 122 are all coated with gradient hardness coatings, and the hardness of the gradient hardness coating increases in a gradient from its interface with the substrate to the surface layer.

[0059] Specifically, the gradient hardness coating consists of three layers from the substrate interface to the surface. The first layer is the bonding layer, 5-10 μm thick, made of NiCrAlY or pure nickel, with a hardness of HV200-250, primarily serving to improve the bonding strength between the coating and the substrate. The second layer is the transition layer, 15-30 μm thick, made of NiCr-Cr3C2 cermet composite, with a hardness gradually increasing from HV400 to HV800, acting as a mechanical buffer. The third layer is the working layer, 10-20 μm thick, made of WC-Co or AlCrN, with a hardness reaching HV1200-1800. The total coating thickness is controlled at 30-60 μm. The gradient hardness coating is prepared using existing supersonic flame spraying or cathodic arc ion plating processes, followed by precision grinding and polishing of the mating surfaces.

[0060] Because of the gradient hardness coating on the surface, the extremely high hardness of the surface layer effectively resists wear and plastic deformation, while the gradient transition layer uniformly transfers the contact stress to the substrate, avoiding the peeling failure caused by the sudden change in interface stress in traditional hard coatings.

[0061] Preferably, such as Figure 3 As shown, the thermal expansion coefficients of the materials of the first pressure block 13 and the second pressure block 14 are greater than those of the material of the expansion block 12, so that the mating gap of the wedge-shaped mating surface is reduced or eliminated when the working temperature rises.

[0062] There are necessary process assembly gaps and machining tolerances between the first pressure block 13, the second pressure block 14 and the expansion and fracture block 12. The difference in the thermal expansion coefficient of the materials allows the gap between the wedge-shaped mating surfaces to automatically decrease as the temperature rises, and even achieve a tight fit with zero gap or no interference when thermal equilibrium is reached, thereby eliminating the instantaneous impact and directional deviation of force transmission caused by the existence of gaps.

[0063] More preferably, the first pressing block 13 and the second pressing block 14 are equipped with heating elements, temperature sensors and temperature control modules.

[0064] The temperature control module is used to control the heating element according to the signal collected by the temperature sensor, so as to heat the first pressure block 13 and the second pressure block 14 to a preset temperature, such as 40°C, before the expansion breaks.

[0065] Specifically, the base material of the first pressure block 13 and the second pressure block 14 is 1Cr18Ni9Ti austenitic stainless steel, which has an average linear expansion coefficient of 17.2×10⁻ in the range of 20-200℃. 6 / ℃. The base material of the expansion joint 12 is Cr12MoV cold work die steel, which has an average linear expansion coefficient of 11.5×10⁻⁻⁻⁶ within the same temperature range. 6 The difference in thermal expansion coefficients between the two is approximately 50%. The cold clearance of the wedge-shaped mating surface is 0.03-0.05 mm. When the working temperature rises to 35℃, the dimensional compensation due to the expansion difference is approximately 0.02-0.03 mm, and the mating surface enters a micro-clearance or zero-clearance state.

[0066] The heating element is built into the internal channels of the first pressure block 13 and the second pressure block 14. Current passes through the heating element, i.e., the resistance wire, causing it to generate Joule heat. The heat is conducted to uniformly raise the temperature of the body of the first or second pressure block 14 (13, 14). When it reaches 40°C, the first pressure block 13 and the second pressure block 14 complete thermal expansion, achieving a gapless or slightly interference fit with the wedge-shaped mating surface of the expansion joint block 12.

[0067] More preferably, the temperature control module is an existing PID controller. The PID controller is used to adjust the heating power of the heating element according to the deviation between the temperature signal collected by the temperature sensor and the preset target temperature value, so as to maintain the constant temperature of the first pressure block 13 and the second pressure block 14.

[0068] Specifically, after the PID controller starts, it enters a self-tuning or preset parameter operation state. The temperature sensor collects real-time temperature signals from the first pressure block 13 and the second pressure block 14 every 0.1-0.5 seconds, and inputs the analog signals to the PID controller after A / D conversion. The controller compares the real-time temperature value with the preset target temperature value and calculates the deviation value e(t). The PID algorithm performs proportional, integral, and derivative operations on the deviation, and outputs a control quantity after a weighted sum. This control quantity adjusts the output power of the heating element through PWM (Pulse Width Modulation). When the actual temperature is lower than the target temperature, the output power increases, and the temperature rises faster; when approaching the target temperature, the integral action eliminates steady-state error, and the derivative action suppresses overshoot, causing the temperature to smoothly converge to the set value and remain constant.

[0069] Preferably, such as Figure 4As shown, the wedge-shaped mating surfaces of the first pressure block 13 and the first inclined guide surface 121, and the wedge-shaped mating surfaces of the second pressure block 14 and the second inclined guide surface 122, are all variable-lift angle curved surfaces. The lift angle of the variable-lift angle curved surfaces monotonically increases along the movement directions of the first pressure block 13 and the second pressure block 14. That is to say, the lift angle of the variable-lift angle curved surfaces increases from small to large along the movement directions of the first pressure block 13 and the second pressure block 14, so that the wedge force amplification ratio decreases from large to small, thereby achieving a large radial expansion force in the early stage of fracture and a small radial expansion force in the later stage of fracture.

[0070] Appendix Figure 4 The dashed lines in the diagram are plane reference lines.

[0071] Specifically, in the initial stage of the fracture stroke, the first pressure block 13 and the second pressure block 14 contact the initial sections of the first inclined guide surface 121 and the second inclined guide surface 122, at which point the helix angle of the wedge-shaped mating surface is small. This small helix angle provides a larger force amplification ratio. As the first pressure block 13 and the second pressure block 14 continue to advance along the direction of motion, the wedge-shaped mating surface slides along the arc length of the variable helix angle curved surface, and the helix angle at the contact position gradually increases according to a preset rule. The increase in the helix angle directly leads to a decrease in the wedge-shaped force amplification ratio, meaning that the radial expansion force converted from the same axial driving force gradually decreases. At this point, the fracture has expanded to the final stage where only a small amount of ligament (the small connection between the connecting rod body and the connecting rod cap) remains, and the wedge-shaped mating enters the larger helix angle region of the variable helix angle curved surface. At this point, the wedge-shaped force amplification ratio has dropped to a lower level than in the initial stage, and the output radial expansion force decreases significantly. The remaining connecting rod ligaments are smoothly separated under a relatively low, steadily decreasing tensile force, avoiding high-energy impact fracture. As a result, the radial expansion force obtained by the expansion block 12 throughout the entire working stroke presents an ideal distribution pattern of "high peak value in the early stage to ensure stable crack initiation and low and stable value in the later stage to protect the quality of the fracture surface". This suppresses defects such as thickening of plastic deformation layer, burrs and flash and shedding of fine debris caused by severe ligament fracture from the mechanical source, and significantly improves the smoothness of the fracture surface.

[0072] More preferably, the variable helix angle surface is a continuous differentiable surface, whose helix angle increases monotonically from 5°~7° to 15°~20° along the direction of motion, and the rate of change of the helix angle of adjacent micro-segments does not exceed 3° / mm.

[0073] Although the illustrative specific embodiments of the present invention have been described above to enable those skilled in the art to understand the invention, the invention is not limited to the scope of the specific embodiments. For those skilled in the art, all inventions utilizing the concept of the present invention are protected as long as various variations are within the spirit and scope of the invention as defined and determined by the appended claims.

Claims

1. A double-wedge self-balancing connecting rod processing equipment, comprising a base, a clamping mechanism disposed on the base, and a fracture mechanism capable of engaging with the big end hole of the connecting rod; The clamping mechanism has a top rod that abuts against the bolt support surfaces on both sides of the big end of the connecting rod, and the expansion mechanism includes a fixed block fixed to the base and an expansion block that can move relative to the fixed block; Its features are, The opposite end faces of the expansion block and the fixed block are respectively provided with a first inclined guide surface and a second inclined guide surface that are inclined towards each other and intersect, together forming a convex triangular structure; A first pressing block and a second pressing block are provided between the fixed block and the expansion block. The first pressing block and the first inclined guide surface, as well as the second pressing block and the second inclined guide surface, are wedge-shaped fits. The dual-bar actuator on the base is used to drive the first pressure block and the second pressure block to move synchronously in opposite directions, so that the radial components of the forces acting on the fracture block by the first pressure block and the second pressure block are superimposed in the same direction and cancel each other out of the lateral components acting on the fracture block. This drives the fracture block to expand radially outward without additional overturning moment, causing the connecting rod big end hole to fracture along a preset fracture path.

2. The double-wedge self-balancing connecting rod processing equipment according to claim 1, characterized in that, It also includes a moving mechanism having a sliding plate that slides with a guide rail on the base, the expansion block being fixed on the sliding plate, and the sliding plate having a positioning part for engaging with the small end hole of the connecting rod.

3. The double-wedge self-balancing connecting rod processing equipment according to claim 1, characterized in that, The dual-rod actuator is a dual-piston rod hydraulic cylinder, which includes a first rod and a second rod capable of synchronous and reverse movement. The first rod passes through the central shaft hole of the second pressure block and is fixedly connected to the first pressure block. The second rod is fixedly connected to the second pressure block through a connecting rod.

4. The double-wedge self-balancing connecting rod processing equipment according to claim 3, characterized in that, The second pressure block has a sliding bearing bushing in its central shaft hole, and the first rod body slides in conjunction with the sliding bearing bushing.

5. The double-wedge self-balancing connecting rod processing equipment according to claim 1, characterized in that, The first pressing block, the second pressing block, the first inclined guide surface, and the second inclined guide surface are all coated with a gradient hardness coating. The hardness of the gradient hardness coating increases in a gradient from its interface with the substrate to the surface layer.

6. The double-wedge self-balancing connecting rod processing equipment according to claim 1, characterized in that, The thermal expansion coefficients of the materials of the first and second pressure blocks are greater than those of the material of the fracture block, so that the mating gap of the wedge-shaped mating surface is reduced or eliminated when the working temperature rises.

7. The double-wedge self-balancing connecting rod processing equipment according to claim 6, characterized in that, The first and second pressing blocks are equipped with heating elements, temperature sensors, and temperature control modules. The temperature control module is used to control the heating element according to the signal collected by the temperature sensor, so as to heat the first pressure block and the second pressure block to a preset temperature before they break.

8. The double-wedge self-balancing connecting rod processing equipment according to claim 7, characterized in that, The temperature control module is a PID controller. The PID controller is used to adjust the heating power of the heating element according to the deviation between the temperature signal collected by the temperature sensor and the preset target temperature value, so as to maintain the constant temperature of the first pressing block and the second pressing block.

9. The double-wedge self-balancing connecting rod processing equipment according to claim 1, characterized in that, The wedge-shaped mating surface between the first pressing block and the first inclined guide surface, and the wedge-shaped mating surface between the second pressing block and the second inclined guide surface are both variable-lift angle curved surfaces, and the lift angle of the variable-lift angle curved surfaces increases monotonically along the movement direction of the first pressing block and the second pressing block.

10. The double-wedge self-balancing connecting rod processing equipment according to claim 9, characterized in that, The variable lift angle surface is a continuous guideable surface, and its lift angle increases monotonically from 5°~7° to 15°~20° along the direction of motion, and the lift angle change rate of adjacent micro-segments does not exceed 3° / mm.

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