Die-casting die for a steering knuckle of a vehicle

Abstract

The application discloses a die-casting die for an automobile steering knuckle, which comprises an upper die plate, a lower die plate, an upper die and a lower die arranged between the upper die plate and the lower die plate, a die cavity is formed between the upper die and the lower die, a feeding port is arranged at the top of the upper die plate, a feeding cylinder is arranged in the upper die and corresponds to the feeding port, a conical buffer mandrel is coaxially arranged at the position close to the upper part in the feeding cylinder, left and right pull-out plate assemblies are arranged at the two sides between the upper die plate and the lower die plate, the left and right pull-out plate assemblies are respectively provided with left and right forming plates which are slid into the upper die, opposite ends of the left and right forming plates are provided with forming panels which can be connected, and the left and right forming plates are connected at the lower end of the feeding cylinder to form a circular hollow part to form a circular table of the automobile steering knuckle and a groove outside the circular table. The application solves the problems that the existing die-casting die cannot form a complete automobile steering knuckle at one time and cannot resist the impact of aluminum liquid for a long time.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of automobile parts production, in particular to a die-casting die for automobile steering knuckles. BACKGROUND

[0002] The automobile steering knuckle is a core load-bearing and force-transmitting component in the automobile chassis system, and its structural integrity and dimensional accuracy directly determine the driving safety of the vehicle. The end of the steering knuckle is usually designed with an integrated circular truncated cone structure, and an annular groove needs to be machined on the outer side of the circular truncated cone. The groove is used for subsequent assembly of a dust cover or positioning connector and is a key functional structure of the steering knuckle.

[0003] In the current die-casting production of automobile steering knuckles, there are significant technical bottlenecks in the forming of the above-mentioned circular truncated cone and annular groove. On the one hand, the forming area of the circular truncated cone and the groove needs to be axially corresponding to the feeding system of the die-casting die, and the space in this area is narrow. Traditional dies are difficult to design components with both sliding function and forming precision. If a fixed forming structure is used, it cannot be demoulded. If a large sliding core-pulling mechanism is used, it will interfere with the feeding cylinder, resulting in a bulky die, and making it inconvenient to operate. On the other hand, during high-pressure die casting, the aluminum liquid is injected from the feeding cylinder at a high speed of 40-50 m / s, directly impacting the surface of the component used to form the circular truncated cone and the groove. This impact not only causes wear of the component, but also causes turbulent flow of the aluminum liquid, resulting in defects such as shrinkage holes and pores at the root of the circular truncated cone, with a high defect rate.

[0004] To avoid the above problems, the industry generally adopts a process mode combining die-casting rough casting with post-processing: only the main structure of the steering knuckle is formed during die-casting, and the circular truncated cone and the groove are completed by subsequent numerical control milling. This mode can ensure structural accuracy, but has obvious drawbacks: first, post-processing requires additional investment in numerical control equipment and labor, increasing the cost of single-piece production; second, the milling process will damage the metal flow lines of the die-cast part, resulting in a decrease in the fatigue strength of the circular truncated cone area and posing a safety hazard; third, the processing cycle is prolonged, the production efficiency is reduced, and it cannot meet the large-scale production demand of automobile parts.

[0005] Therefore, it is a technical problem to be solved in the current field to develop a die-casting die that can directly form the circular truncated cone and the groove of the steering knuckle and resist the impact of the aluminum liquid, achieving one-step die-casting forming. SUMMARY

[0006] The present application provides a die-casting die for automobile steering knuckles, which can solve the problem that existing die-casting dies cannot form complete automobile steering knuckles in one step and cannot resist the impact of aluminum liquid for a long time.

[0007] In order to achieve the above object, the present application provides the following technical scheme: a die-casting die for automobile steering knuckle, comprising an upper die plate, a lower die plate, an upper die and a lower die arranged between the upper die plate and the lower die plate, a die cavity is formed between the upper die and the lower die, a feeding port is arranged at the top of the upper die plate in the middle, a feeding cylinder is installed in the upper die corresponding to the feeding port, a tapered buffer mandrel is coaxially arranged inside the feeding cylinder near the upper part, left and right pull-out plate assemblies are arranged on both sides between the upper die plate and the lower die plate, the left and right pull-out plate assemblies respectively have left and right forming plates which extend into the upper die and slide, opposite ends of the left and right forming plates are provided with forming panels which can be connected, the left and right forming plates are connected at the lower end of the feeding cylinder to form a circular hollow part to form the end circular table of the automobile steering knuckle and the groove outside the circular table, flat forming plates and small volume forming panels are used, the idle space in the upper die is used to arrange the sliding structure to avoid interference with the feeding cylinder, one-time die-casting forming of the circular table and the groove is realized, the post-processing process is saved, the cost of a single piece is reduced, and the production efficiency is improved; the tapered buffer mandrel changes the flow trajectory of the aluminum liquid to avoid direct shooting of the aluminum liquid to the forming panel, so that the wear period of the forming panel is prolonged; the circular hollow part corresponds to the axial direction of the feeding cylinder, the aluminum liquid is directly filled into the forming area, the filling path is reduced, and the integrity of the circular table forming is improved.

[0008] Preferably, the tapered buffer mandrel comprises a top tapered section, a middle cylindrical guide section and a bottom fixed section from top to bottom, the bottom fixed section comprises at least two support ribs arranged circumferentially around the bottom end of the middle cylindrical guide section, the outer ends of the support ribs are fixed to the inner wall of the feeding cylinder, the three-section structure of the tapered buffer mandrel lowers the center of gravity of the mandrel, the circumferential distribution of the support ribs forms stable support, the radial jumping amount of the tapered buffer mandrel under the impact of the aluminum liquid is small, and the aluminum liquid flow is prevented from being disturbed due to the shaking of the mandrel.

[0009] Preferably, the top of the top tapered section is provided with a hemispherical end, the hemispherical end converts the point impact of the aluminum liquid into surface contact, and cracks are prevented from being generated in the mandrel due to long-term impact.

[0010] Preferably, a plurality of arc-shaped guide grooves are uniformly distributed around the circumference of the edge of the top tapered section, the arc-shaped guide grooves provide a guide track for the circumferential rotation of the aluminum liquid, the angular velocity of the rotation of the aluminum liquid is increased from 1400 rad / s to 1800 rad / s, and the spiral flow state is more stable.

[0011] As preferred, the two side walls of the support rib are streamline curved surfaces, the streamline curved surfaces reduce the flow resistance coefficient when the molten aluminum flows through the support rib, the loss of the flow velocity of the molten aluminum is small, the filling speed is ensured to meet the requirement of high-pressure die casting, the scouring and wearing of the molten aluminum to the support rib are reduced, and the service life of the support rib is prolonged.

[0012] As preferred, the taper angle of the top end tapered section is 60°, the optimal matching of the radial acceleration of the molten aluminum and the circumferential rotation speed is achieved by the taper angle of 60°, the filling speed of the molten aluminum is ensured, and the flow state is prevented from being broken due to too fast rotation.

[0013] As preferred, the left and right pull-out plate assemblies each comprise a driving oil cylinder mounted on the outer side of the upper die plate and a sliding block driven by the driving oil cylinder, the end portions of the left and right forming plates are connected with the corresponding sliding blocks, the end of the forming panel is provided with a stepped limiting block, the stepped limiting block is limited between the sliding block and the corresponding left or right forming plate, the oil cylinder drives the sliding block to guide, the sliding of the forming plate is repeated, the positioning precision is high, the stepped limiting block realizes the quick disassembly and assembly of the forming panel, the limiting block fixes the panel firmly, and the panel has no displacement during die casting.

[0014] As preferred, the relatively butted position of the left and right forming plates is provided with a first sealing butt joint structure formed by the embedding of the first sealing protrusion and the first sealing groove, the embedded structure greatly reduces the butt joint gap of the forming plates, reduces the penetration amount of the molten aluminum, and makes the flash thickness of the forming plate region very small; and the impact displacement of the molten aluminum to the forming plate can be reduced.

[0015] As preferred, the relatively butted position of the two forming panels is provided with a second sealing butt joint structure formed by the embedding of the second sealing protrusion and the second sealing groove, the embedded structure ensures the accurate butt joint of the semicircular grooves of the two forming panels, the round hollow part has a small roundness error, and meanwhile, the cooperation of the second sealing protrusion and the second sealing groove reduces the contact area of the molten aluminum and the butt joint surface of the panel, so that the panel and the product are separated more smoothly during demolding.

[0016] As preferred, the forming panel is internally provided with a circulating cooling flow channel extending to the circular hollow part, the circulating cooling flow channel is close to the groove forming surface, the temperature of the panel is stabilized at 240-280 DEG C, the cooling rate of the circular platform is uniform, and the shrinkage defect rate is reduced. The cooling flow channel takes away the impact heat, and the thermal deformation amount of the panel is reduced.

[0017] Compared with the prior art, the present application has the following beneficial effects:

[0018] Compact structure, adopt flat forming plate and small volume forming panel, use the idle space in the upper die to arrange the sliding structure, avoid interference with the feeding cylinder, realize the one-time die casting forming of the circular table and the groove, save the post-processing process, reduce the cost of single piece and improve the production efficiency; The conical buffer mandrel changes the flow trajectory of the aluminum liquid, avoids the aluminum liquid directly forming the panel, prolongs the wear period of the forming panel; The circular hollow part corresponds to the axial direction of the feeding cylinder, the aluminum liquid is directly filled into the forming area, the filling path is reduced, and the integrity of the circular table is improved. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a perspective view of the present application;

[0020] Figure 2 is a front view of the present application;

[0021] Figure 3 is Figure 2 an enlarged view of A;

[0022] Figure 4 is a partial perspective view of the present application;

[0023] Figure 5 is a partial top view of the present application;

[0024] Figure 6 is Figure 5 a D-D cross-sectional view of;

[0025] Figure 7 is Figure 6 an enlarged view of B;

[0026] Figure 8 is a top view of the feeding cylinder of the present application.

[0027] REFERENCE NUMERALS:

[0028] 1, upper die plate, 11, circular hollow part, 12, mold cavity, 2, lower die plate, 3, feeding port, 4, left pullout plate assembly, 41, drive oil cylinder, 42, left forming plate, 43, sliding block, 44, right forming plate, 45, forming panel, 46, step limiting block, 5, right pullout plate assembly, 51, first sealing protrusion, 52, second sealing protrusion, 53, circulating cooling runner, 6, feeding cylinder, 7, conical buffer mandrel, 71, top conical section, 72, middle cylindrical guide section, 73, hemispherical end, 74, support rib, 75, arc-shaped guide groove, 8, detachable forming column, 9, lower die, 10, upper die. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application.

[0030] As Figures 1-8 shown, the present application provides a die-casting die for automobile steering knuckle, which comprises an upper die plate 1, a lower die plate 2, an upper die 10 and a lower die 9 arranged between the upper die plate 1 and the lower die plate 2, a die cavity 12 formed between the upper die 10 and the lower die 9, a feeding port 3 arranged at the top of the upper die plate 1, a feeding cylinder 6 installed in the upper die 10 corresponding to the feeding port 3, a tapered buffer mandrel 7 coaxially arranged inside the feeding cylinder 6 close to the upper part, a left draw plate assembly 4 and a right draw plate assembly 5 arranged on both sides of the upper die plate 1 and the lower die plate 2, respectively, the left draw plate assembly 4 and the right draw plate assembly 5 each having a left forming plate 42 and a right forming plate 44 sliding into the upper die 10, opposite ends of the left forming plate 42 and the right forming plate 44 being provided with forming panels 45 capable of being connected, and the left forming plate 42 and the right forming plate 44 being connected at the lower end of the feeding cylinder 6 to form a circular hollow part 11 for forming the end circular platform of the automobile steering knuckle and the groove outside the circular platform. The flat forming plate and the small volume forming panel 45 are arranged in the idle space inside the upper die 10 to avoid interference with the feeding cylinder 6, realize one-step die-casting forming of the circular platform and the groove, save the post-processing process, reduce the cost of single piece, and improve the production efficiency. The tapered buffer mandrel 7 changes the flow trajectory of the aluminum liquid to avoid direct shooting of the forming panel, prolongs the wear period of the forming panel, and the circular hollow part is axially corresponding to the feeding cylinder, the aluminum liquid is directly filled into the forming area, the filling path is reduced, and the circular platform forming integrity is improved.

[0031] In this embodiment, the die is suitable for a model of "HH23006" automobile steering knuckle, the diameter of the circular platform is Φ50mm, the groove width is 8mm, and the depth is 3mm. The upper die plate 1 and the lower die plate 2 are forged and processed by 45 steel, and the thicknesses are 80mm and 100mm, respectively; the upper die 10 and the lower die 9 are made of ESR-H13 hot work die steel. The feeding port 3 is trumpet-shaped, the feeding cylinder 6 is cylindrical, and is installed in the feeding hole of the upper die 10 through interference fit, and the lower end is axially aligned with the circular platform forming area; in order to effectively form the automobile steering knuckle, a detachable forming column 8 can be embedded in the lower die 9, a relatively deep groove is arranged in the inside of the detachable forming column 8 for forming the structure of the automobile steering knuckle, and cooling water can be introduced into the inside of the detachable forming column 8 to achieve rapid cooling.

[0032] Specifically, the traditional direct jet will directly impact the inner wall of the circular cone forming cavity, and part of the molten aluminum will penetrate into the gap of the panel butt joint surface after rebounding, forming a large amount of residue that needs to be cleaned by a residue discharge groove. At the same time, the impact will cause uneven stress on the panel butt joint surface, accelerating the local wear of the wear-resistant alloy sheet. The spiral flow guided by the conical buffer mandrel 7 flows along the wall of the cavity, and the flow direction of the molten aluminum is parallel to the panel butt joint surface, rather than vertically impacting. The impact pressure is reduced from 15 MPa to 6 MPa, reducing the penetration of molten aluminum into the butt joint gap. At the same time, the centrifugal force of the spiral flow causes impurities in the molten aluminum to gather towards the center of the cavity, reducing the contact between impurities and the panel butt joint surface, and reducing the amount of residue collected by the residue discharge groove.

[0033] At the same time, the air entrained by the traditional direct jet will form air holes at the root of the circular cone, causing the product to be partially suspended from the panel forming surface, and the negative pressure distribution to be uneven during demolding. The negative pressure in some areas is too large, and even if the negative pressure breaking hole is opened, it may also cause the product to deform. At the same time, the air holes will increase the friction coefficient between the product and the panel, increasing the demolding force. The spiral flow of the conical buffer mandrel 7 efficiently discharges the gas in the cavity through centrifugal force, and the air hole rate at the root of the circular cone is greatly reduced, and the product surface is more evenly attached to the panel forming surface.

[0034] In the present embodiment, the conical buffer mandrel 7 includes a top tapered section 71, a middle cylindrical guide section 72, and a bottom fixed section from top to bottom. The bottom fixed section includes at least two support ribs 74 circumferentially arranged around the bottom end of the middle cylindrical guide section 72. The outer ends of the support ribs 74 are fixed to the inner wall of the feeding cylinder 6. The three-section structure of the conical buffer mandrel 7 lowers the center of gravity of the mandrel, and the circumferential distribution of the support ribs 74 provides stable support. The radial jumping amount of the conical buffer mandrel 7 under the impact of the molten aluminum is small, avoiding the flow disorder of the molten aluminum caused by the shaking of the mandrel. The middle cylindrical guide section 72 and the feeding cylinder 6 form an annular flow channel with uniform width, the flow velocity of the molten aluminum fluctuates little, and the filling consistency is improved. Specifically, the taper angle of the top tapered section 71 is 60°. The 60° taper angle optimizes the radial acceleration of the molten aluminum and the circumferential rotation speed, ensuring the filling speed of the molten aluminum and avoiding the flow state breaking caused by excessive rotation. The total length of the conical buffer mandrel 7 is 50 mm, the material is ESR-H13 steel, and the surface is treated with ion nitriding + PVDTiN coating. The top tapered section 71 is 15 mm high, the taper angle is 60°, and the top hemispherical end 73 has a radius of 3 mm. Six arc-shaped guide grooves 75 are evenly distributed circumferentially around the edge. The middle cylindrical guide section 72 is 10 mm in diameter and 20 mm in length. The bottom fixed section is 10 mm long and circumferentially welded with four support ribs 74. The outer ends of the support ribs 74 are fixed to the inner wall of the feeding cylinder 6 by argon arc welding, and the weld is polished smooth and flush with the cylinder wall.

[0035] In addition, the edge of the top tapered section 71 is uniformly distributed with a plurality of arc-shaped guide grooves 75 around the circumference, the arc-shaped guide grooves 75 provide a circumferential rotation guide track for the aluminum liquid, so that the angular velocity of the rotation of the aluminum liquid is increased from 1400 rad / s to 1800 rad / s, and the spiral flow state is more stable; the rotating aluminum liquid pushes the gas to the edge of the cavity under the action of centrifugal force, and cooperates with the exhaust groove to improve the exhaust efficiency of the cavity.

[0036] In addition, the two side walls of the support rib 74 are streamline curved surfaces, the streamline curved surfaces reduce the along-path resistance coefficient when the aluminum liquid flows through the support rib, the aluminum liquid flow velocity loss is relatively small, the filling speed is ensured to meet the high-pressure die casting requirement, the scouring and wear of the aluminum liquid to the support rib are reduced, and the service life of the support rib is prolonged.

[0037] Further, the top of the top tapered section 71 is provided with a hemispherical end 73, the hemispherical end 73 converts point impact of the aluminum liquid into surface contact, avoids cracks of the mandrel due to long-term impact, and the hemispherical surface has no edges and corners, so that vortex is not formed when the aluminum liquid flows through, and the gas entrainment amount is reduced.

[0038] As the fluid mechanics principle of the spiral flow of the aluminum liquid formed by the tapered buffer mandrel 7 in the embodiment:

[0039] First stage: radial contraction and acceleration

[0040] The aluminum liquid enters the feeding cylinder 6 from the pressure chamber, and the flow cross section changes from an annular shape to a tapered annular gap after encountering the tapered buffer mandrel 7, according to the continuity equation (Q=Av), the cross section contraction causes the flow velocity to increase radially, and a radial pressure gradient is generated at the same time, so that the aluminum liquid obtains a component velocity in the direction of the mandrel generatrix, which lays a foundation for subsequent spiral motion;

[0041] Second stage: circumferential rotation induction, the joint action of the top tapered section 71 and the arc-shaped guide groove 75

[0042] The top tapered section 71 forces the aluminum liquid to flow in the direction of the generatrix, and is constrained by the inner wall of the feeding cylinder 6 at the same time, the radial contraction force and the circumferential constraint force make the aluminum liquid generate an initial rotation around the axis of the mandrel, and the arc-shaped guide groove 75 assists, the surface of the top tapered section 71 converts linear momentum into rotational momentum, and vortex generation effect is formed;

[0043] Third stage: stable spiral flow formation, maintained through the middle section cylindrical guide section 72

[0044] After the molten aluminum enters the middle section cylindrical guide section 72, the rotating flow is stably maintained, forming a fixed-pitch spiral flow. The uniform gap of the annular flow channel provides consistent flow resistance, ensuring the stability and uniformity of the spiral flow. The streamline coincides with the vortex line, and the aluminum liquid particles have both axial velocity and circumferential angular velocity, thereby forming a complete spiral trajectory. The spiral flow makes the molten aluminum uniformly advance along the cavity wall, forming an overall forward flow, avoiding the jet-flow-back mode of traditional straight jet flow.

[0045] The top end of the conical buffer mandrel 7 is 3mm away from the entrance plane of the circular table forming cavity and is located inside the feeding cylinder, only guiding the flow of molten aluminum, and does not contact the surface of the formed knuckle circular table, so there is no risk of sticking.

[0046] The cross-sectional area of the annular flow channel between the conical buffer mandrel 7 and the feeding cylinder 6 can be matched with the design of high-pressure die casting requirements, for example: the inner diameter of the feeding cylinder is 20mm, the maximum diameter of the conical mandrel is 10mm, the area of the annular flow channel is approximately 3.14×(10²-5²)=235.5mm², if the flow rate of the molten aluminum in the flow channel is 50m / s, the volume flow rate can reach 235.5mm²×50m / s≈11.8L / s, which fully meets the filling requirements of small and medium-sized knuckles. And the 60° taper angle of the conical mandrel is optimized through fluid simulation, which can stably form a spiral flow in the main flow rate range of 50-80m / s, and adapt to the pressure output of different models of 800-1500 die casting machines.

[0047] In the embodiment, the left and right pull plate assemblies 4 and 5 each include a driving oil cylinder 41 mounted on the outside of the upper die plate 1 and a sliding block 43 driven by the driving oil cylinder 41, the ends of the left and right forming plates 42 and 44 are connected to the corresponding sliding blocks 43, the ends of the forming panels 45 are provided with step limiting blocks 46, the step limiting blocks 46 are limited between the sliding blocks 43 and the corresponding left or right forming plates 42 and 44, the oil cylinder driving cooperates with the sliding block guide, the forming plate sliding has high repeated positioning accuracy, the step limiting block 46 realizes quick disassembly and assembly of the forming panel 45, and the limiting block fixes the panel firmly, and the panel has no displacement during die casting; specifically, the left and right pull plate assemblies 4 and 5 are symmetrically arranged, the driving oil cylinder 41 is type HOB63×100 and is fixed to the outside of the upper die plate 1 through a flange; the sliding block 43 is a T-shaped structure and cooperates with a T-shaped sliding slot in the upper die 10 with a gap, the oil cylinder piston rod is connected to the sliding block 43 through threads; the left and right forming plates 42 and 44 are flat, one end is bolted to the sliding block 43, and the other end extends into the upper die 10; the forming panel 45 is a flat sheet, semicircular grooves are machined at opposite ends, a Φ50mm circular hollow part 11 is formed after docking, and annular protrusions are machined on the inner side of the groove. The step limiting block 46 at the end of the forming panel 45 clamps the panel between the sliding block 43 and the forming plate.

[0048] In the embodiment, the left forming plate 42 and the right forming plate 44 are provided with a first sealing butt joint structure formed by the first sealing protrusion 51 and the first sealing groove at the position of relative butt joint, the embedded structure greatly reduces the gap of the forming plate butt joint, reduces the penetration amount of the aluminum liquid, and reduces the flash thickness of the forming plate area; the impact displacement of the aluminum liquid to the forming plate can be reduced; specifically, the left forming plate 42 is provided with a first sealing protrusion 51 with a width of 5 mm and a height of 2 mm at the end, the right forming plate 44 is provided with a corresponding first sealing groove at the end, and the gap after embedding is less than or equal to 0.02 mm.

[0049] In the embodiment, the two forming panels 45 are provided with a second sealing butt joint structure formed by the second sealing protrusion 52 and the second sealing groove at the position of relative butt joint, the embedded structure ensures the precise butt joint of the semicircular grooves of the two forming panels 45, the round hollow part has a small roundness error, and meanwhile, the cooperation of the second sealing protrusion 52 and the second sealing groove reduces the contact area of the aluminum liquid and the panel butt joint surface, so that the panel and the product are separated more smoothly during demolding; the semicircular groove edge of the forming panel 45 is provided with a second sealing protrusion 52 with a width of 3 mm and a height of 1 mm, and the corresponding panel is provided with a second sealing groove, and the gap after embedding is less than or equal to 0.01 mm.

[0050] In the embodiment, the forming panel 45 is provided with a circulating cooling flow channel 53 extending to the circular hollow part 11, the circulating cooling flow channel 53 is close to the groove forming surface, so that the panel temperature is stabilized at 240-280℃, the cooling rate of the circular table is uniform, and the shrinkage defect rate is reduced. The cooling flow channel carries away the impact heat, and the thermal deformation amount of the panel is reduced.

[0051] As a specific work flow in the embodiment:

[0052] (1) Mold closing and preheating: the upper mold plate 1 is driven downward by the die casting machine, the upper mold 10 and the lower mold 9 are closed, the mold locking force is set to 1200kN; the heating system is started, and the panel temperature is preheated to 220℃ by the flexible heating sheet of the forming panel 45, and the overall temperature of the mold is preheated to 200℃.

[0053] (2) Plate extraction and butt joint: the control system starts the left / right drive cylinder 41, pushes the sliding block 43 to drive the forming plate and the forming panel 45 to slide to the center, until the first and second sealing structures are completely embedded, the circular hollow part 11 is formed, and the oil cylinder is pressure-kept.

[0054] (3) Filling of aluminum liquid: the aluminum alloy liquid with a temperature of 700℃ enters the feeding cylinder 6 from the feeding port 3 through the pressure of the pressure chamber; the aluminum liquid forms a spiral flow under the guidance of the conical buffer core shaft 7, fills the mold cavity 12 at a speed of 40m / s, and the filling time is 0.12 seconds.

[0055] (4) Pressure and cooling: after filling, pressure for 5 seconds, while starting cooling system, circulating cooling flow channel 53 into cooling liquid, the temperature of the forming panel is controlled at about 260℃, the overall cooling time is 15 seconds.

[0056] (5) Mold opening and demolding: first control the oil cylinder pressure relief, drive the forming plate and the forming panel 45 to retreat outward, start the ejector mechanism after 3 seconds, the product is ejected, and the demolding is completed.

[0057] In the traditional mold, when the aluminum liquid directly impacts the formed part, an impact high pressure area is formed on the surface of the part, which is not only a heavy wear area, but also a source of turbulent gas. In the embodiment, the conical buffer mandrel 7 converts the linear impact flow of the aluminum liquid into a spiral wall-flow by the combined design of the 60° taper and the arc-shaped guide groove 75. According to the continuity equation of fluid mechanics (Q=Av), the flow velocity of the aluminum liquid in the annular flow channel is increased from 45m / s to 50m / s, but the flow direction is parallel to the surface of the forming panel, and the impact pressure is reduced from 15MPa to 6MPa. At the same time, the centrifugal force of the spiral flow moves the impurities and gas in the aluminum liquid to the edge of the cavity, avoiding accumulation on the forming surface of the groove of the forming panel, and reducing the abrasive wear of the panel.

[0058] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative positional relationship, motion condition, etc. between the components in a certain specific posture (as shown in the drawings), and if the specific posture changes, the directional indications will also change accordingly.

[0059] In addition, in the present application, the description such as "first", "second" and the like is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise specifically limited.

[0060] In the present application, unless otherwise specifically defined and limited, the terms "connection", "fixing" and the like should be understood broadly, for example, "fixing" can be fixed connection, or detachable connection, or integral; can be mechanical connection, or electrical connection; can be directly connected, or indirectly connected through an intermediate medium; can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise specifically limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0061] In addition, the technical solutions among various embodiments of the present application can be combined with each other, but must be based on the fact that a person of ordinary skill in the art can realize the combination, and when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist and is not within the protection scope required by the present application.

Claims

1. A die casting mold for an automobile knuckle, comprising an upper mold plate (1), a lower mold plate (2), and an upper mold (10) and a lower mold (9) provided between the upper mold plate (1) and the lower mold plate (2), the upper mold (10) and the lower mold (9) forming a mold cavity (12) therebetween, characterized in that, The top of the upper die plate (1) is centrally provided with a feeding port (3), the upper die (10) is provided with a feeding cylinder (6) corresponding to the feeding port (3), the feeding cylinder (6) is coaxially provided with a conical buffer mandrel (7) at a position close to the upper part inside, the left and right sides between the upper die plate (1) and the lower die plate (2) are respectively provided with a left draw plate assembly (4) and a right draw plate assembly (5), the left draw plate assembly (4) and the right draw plate assembly (5) respectively have a left forming plate (42) and a right forming plate (44) which extend into the upper die (10) to slide, the opposite ends of the left forming plate (42) and the right forming plate (44) are provided with a formable panel (45) which can be connected, the left forming plate (42) and the right forming plate (44) are connected at the lower end of the feeding cylinder (6) to form a circular hollow part (11) to form the end circular table of the automobile steering knuckle and the groove outside the circular table, the conical buffer mandrel (7) sequentially comprises a top conical section (71), a middle cylindrical guide section (72) and a bottom fixed section from top to bottom, the bottom fixed section comprises at least two support ribs (74) which are circumferentially arranged at the bottom of the middle cylindrical guide section (72), the outer side of the support rib (74) is fixed with the inner wall of the feeding cylinder (6).

2. The die casting mold for an automobile knuckle according to claim 1, characterized by: The top of the top conical section (71) is provided with a hemispherical end (73).

3. The die casting mold for an automobile knuckle according to claim 1, characterized by: The edge of the top conical section (71) is uniformly distributed with a plurality of arc guide grooves (75) around the circumference.

4. The die casting mold for an automobile knuckle according to claim 1, characterized by: The two side walls of the support rib (74) are streamline curved surfaces.

5. The die casting mold for an automobile knuckle according to claim 1, characterized by: The taper angle of the top conical section (71) is 60°.

6. The die casting mold for an automobile knuckle according to claim 1, characterized by: The left draw plate assembly (4) and the right draw plate assembly (5) each comprise a drive oil cylinder (41) mounted on the outside of the upper die plate (1) and a sliding block (43) driven by the drive oil cylinder (41), the end of the left forming plate (42) and the right forming plate (44) is connected with the corresponding sliding block (43), the end of the formable panel (45) is provided with a stepped limiting block (46), and the stepped limiting block (46) is limited between the sliding block (43) and the corresponding left forming plate (42) or right forming plate (44).

7. The die casting mold for an automobile knuckle according to claim 1, characterized by: The opposite connecting position of the left forming plate (42) and the right forming plate (44) is provided with a first sealing connecting structure formed by a first sealing protrusion (51) and a first sealing groove.

8. The die casting mold for an automobile knuckle according to claim 7, characterized by: The opposite connecting position of the two formable panels (45) is provided with a second sealing connecting structure formed by a second sealing protrusion (52) and a second sealing groove.

9. The die casting mold for an automobile knuckle according to claim 1, characterized by: The inside of the formable panel (45) is provided with a circulating cooling flow channel (53) extending to the circular hollow part (11).

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