A side down thin rim ring casting method for a clutch adjusting ring

Abstract

The application discloses a side-under-thin-edge annular casting method of a clutch adjusting ring, and belongs to the casting technical field. The method adopts DISA vertical molding line to carry out sand molding. The method comprises the following steps: mold preparation, cavity and clutch adjusting ring matching and top and bottom area distinguishing; setting a gating system, which comprises a straight gate, a side-under-thin-edge annular ingate, a cross gate and a bottom pouring ingate, the side-under ingate is arranged at the side-under edge of the cavity, extends in the circumferential direction and has a flat sheet cross section; the top is provided with an annular hot riser extending in the circumferential direction and is provided with a plurality of uniformly distributed riser necks; during pouring, the side-under ingate is poured first and has a larger pouring amount than the bottom pouring ingate, when the liquid surface rises to 60%-80% of the cavity height, the side-under pouring rate is reduced and the bottom pouring rate is increased; and the top and the bottom are differentially cooled to form a top-down sequential solidification temperature gradient. The application can effectively solve the problems of insufficient feeding and oval deformation of the annular thin-wall casting, and improve the size precision and internal quality of the casting.

Description

Technical Field

[0001] This invention belongs to the field of casting technology, specifically relating to a method for casting a thin-edged ring on the lower side of a clutch adjusting ring. Background Technology

[0002] Clutch adjusting rings are critical components in automotive transmission systems, and are typical thin-walled annular castings with stringent requirements for dimensional accuracy, ovality, and internal density. When using the DISA vertical molding line for mass production with wet-sand molding, these annular castings generally face challenges in feeding and deformation control due to the characteristics of vertical parting, high-speed molding, and asymmetrical cooling conditions. Specifically, annular castings solidify vertically, with molten metal filling the mold from bottom to top. The top area often exhibits shrinkage porosity and defects due to final solidification and obstructed feeding channels. Simultaneously, uneven circumferential cooling causes ovality deformation after demolding, directly affecting the product's roundness compliance rate.

[0003] To address the aforementioned issues, common solutions in existing technologies include adding top risers to enhance feeding, adjusting the gating system layout to improve the filling sequence, and optimizing sand mold hardness to control deformation. However, conventional riser configurations struggle to meet the uniform feeding requirements of annular castings, especially under the high productivity of DISA vertical molding lines, where single-point or local riser solutions often fail to effectively cover the entire annular area. Regarding the gating system, single bottom-pour or side-pour methods struggle to balance filling stability and feeding efficiency, easily leading to air entrapment, sand flushing, or uneven temperature distribution. For controlling elliptical deformation, existing methods primarily rely on post-processing correction or empirical mold allowance adjustments, lacking quantitative pre-set compensation methods based on deformation mechanisms, resulting in poor product consistency and long trial molding cycles.

[0004] Therefore, current technologies for casting clutch adjustment rings in the DISA vertical molding line have not yet achieved a unified approach to shrinkage control and deformation control. The key to solving the shrinkage porosity and elliptical deformation problems of such annular thin-walled castings lies in optimizing the temperature field distribution through multi-gate timing and flow distribution during the pouring and filling stage, achieving uniform circumferential shrinkage through annular hot riser structures during the solidification and shrinkage stage, and simultaneously pre-setting a quantitative anti-ellipticity compensation amount based on the deformation mechanism during the mold design stage. These are also the technical bottlenecks that urgently need to be overcome in this field. Summary of the Invention

[0005] To address the aforementioned problems in the prior art, this invention provides a method for casting a thin-edged annular side of a clutch adjusting ring.

[0006] The objective of this invention can be achieved through the following technical solutions: A method for casting a clutch adjusting ring with a thin side edge, using DISA vertical molding lines for wet sand molding, includes the following steps: Casting preparation steps: Provide a casting cavity, the shape of which matches the clutch adjusting ring, the cavity having a top region and a bottom region; Gating system setup steps: Set up a gating system, which includes a sprue, a side-mounted thin-edged annular ingate, a horizontal runner, and a bottom-ingate. The side-mounted thin-edged annular ingate is located at the lower side edge of the cavity and extends circumferentially along the cavity. The bottom-ingate is connected to the bottom of the cavity. The cross-section of the side-mounted thin-edged annular ingate is a flat, thin sheet. Feeding system setup steps: An annular hot riser is set at the top of the cavity. The annular hot riser extends circumferentially along the cavity, and multiple riser necks are evenly distributed circumferentially on the inner wall of the annular hot riser. Each riser neck is connected to the top of the cavity. Pouring control steps: Molten metal is poured into the cavity through the sprue, and the side-bottom thin-edge annular ingate is controlled to start pouring before the bottom-pour ingate, and the pouring volume of the side-bottom thin-edge annular ingate is greater than that of the bottom-pour ingate; when the molten metal level in the cavity rises to 60%-80% of the cavity height, the pouring speed of the side-bottom thin-edge annular ingate is controlled to decrease, while the pouring speed of the bottom-pour ingate is controlled to increase. Partitioned cooling step: Differentiated cooling control is applied to the top and bottom regions of the cavity to create a sequential solidification temperature gradient from bottom to top along the height direction of the cavity; Unpacking and sand removal steps: After cooling and solidification, unpack and remove the sand to obtain the clutch adjusting ring casting.

[0007] As a preferred embodiment of the present invention, the vertical distance between the center line of the side thin-edged annular inner gate and the lowest point of the cavity is 5%-15% of the total height of the cavity.

[0008] As a preferred embodiment of the present invention, the side-below thin-edged annular ingate extends circumferentially along the cavity at an angle of 120°-270°, the thickness of the side-below thin-edged annular ingate is 0.2-0.4 times the thickness of the casting wall, and the width is 5-15 times the thickness.

[0009] As a preferred embodiment of the present invention, in the pouring control step, the side-bottom thin-edge annular ingate begins pouring 0.5-2 seconds before the bottom-pour ingate; the pouring volume of the side-bottom thin-edge annular ingate accounts for 65%-80% of the total pouring volume, and the pouring volume of the bottom-pour ingate accounts for 20%-35% of the total pouring volume.

[0010] As a preferred embodiment of the present invention, the annular hot riser extends at an angle of 270°-360° along the circumference of the cavity, the width of the annular hot riser is 1.5-3 times the thickness of the casting wall, and the height is 2-4 times the thickness of the casting wall; the number of riser necks is 3-8, and the cross-section of each riser neck is trapezoidal, with the width of the upper base being 0.5-0.8 times the width of the lower base.

[0011] As a preferred technical solution of the present invention, in the mold preparation step, a reverse ellipticity compensation amount is preset in the radial direction of the cavity during the mold design stage, and the reverse ellipticity compensation amount is distributed in a sinusoidal curve along the circumference of the cavity.

[0012] As a preferred technical solution of the present invention, the projection direction of the center line of the sprue in the radial plane of the cavity is taken as the 0° direction reference. The anti-ellipticity compensation amount is the largest in the 0° and 180° directions of the cavity, and the smallest in the 90° and 270° directions.

[0013] As a preferred embodiment of the present invention, the formula for calculating the anti-ellipticity compensation amount is as follows: ,in This is the maximum anti-ellipticity compensation amount. It is an empirical coefficient and its value ranges from 0.3 to 0.8. For the nominal diameter of the casting, This is the coefficient of linear expansion of the material. This is the solidification temperature difference.

[0014] As a preferred embodiment of the present invention, the outer side of the annular hot riser is covered with an insulating sleeve, and an air insulation gap is provided between the inner wall of the insulating sleeve and the outer wall of the annular hot riser; in the partitioned cooling step, an insulating layer is provided in the top region of the cavity, and heat dissipation fins are provided in the bottom region of the cavity, and the heat dissipation fins are evenly distributed circumferentially.

[0015] As a preferred embodiment of the present invention, the chemical composition of the molten metal, by mass percentage, is: C 3.20%-3.50%, Si 1.90%-2.30%, Mn 0.60%-0.90%, P≤0.15%, S≤0.15%, with the balance being Fe and unavoidable impurities; the pouring temperature of the molten metal is 1420±40℃, and the tapping temperature is 1500±40℃; the hardness of the sand mold is ≥85B type, and the thickness of the sand mold is 170-230mm.

[0016] The beneficial effects of this invention are as follows: through the coordinated design of the gating system, the feeding system, the gating control and the zoned cooling, the problem of insufficient feeding and elliptical deformation of the annular thin-walled casting when casting the clutch adjustment ring in the DISA vertical molding line wet sand casting is effectively solved. The side-mounted thin-edged annular ingate, located at the lower edge of the cavity and with a flat, thin cross-section, combines the timing and flow distribution of its pre-pouring and dominant pouring volume with the dynamic switching of the side-mounted ingate speed decreasing and the bottom-mounted ingate speed increasing when the liquid level rises to 60%-80% of the cavity height. This achieves stable and rapid low-level filling and active temperature field control in the later stages of pouring, preventing air entrapment, sand flushing, and top overheating. The annular hot riser extends circumferentially and is equipped with multiple evenly distributed riser necks. Combined with the zoned cooling control of top insulation and bottom heat dissipation, it forms a bottom-up sequential solidification temperature gradient, ensuring uniform circumferential shrinkage and eliminating shrinkage cavities. During the mold design stage, a sinusoidally distributed anti-ellipticity compensation amount is preset along the cavity circumference to actively compensate for elliptical deformation caused by uneven solidification shrinkage, significantly improving the roundness of the casting. These methods organically unify filling, shrinkage compensation, and deformation control, simultaneously improving the dimensional accuracy and internal quality of the casting, resulting in good product consistency. Attached Figure Description

[0017] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0018] Figure 1 This is a schematic diagram of the method flow of the present invention; Figure 2 This is a schematic diagram of the pouring control logic of the present invention; Figure 3 This is a schematic diagram of the anti-ellipticity compensation and cooling of the present invention. Detailed Implementation

[0019] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided.

[0020] Please see Figures 1 to 3 This invention provides a method for casting a thin-walled ring with a side profile for a clutch adjusting ring. This method employs a DISA vertical molding line for wet sand casting and is suitable for mass production of precision clutch adjusting rings. Through the coordinated design of the gating system, feeding system, gating control, and zoned cooling, this method effectively solves the technical challenges of insufficient feeding and elliptical deformation in thin-walled ring castings during DISA vertical molding line wet sand casting of clutch adjusting rings.

[0021] The above method mainly includes the following steps: mold preparation, gating system setup, feeding system setup, gating control, zoned cooling, and sand removal.

[0022] Mold preparation steps In the mold preparation step, a casting cavity is first provided, the shape of which matches the clutch adjusting ring. The cavity has a top region and a bottom region; the top region corresponds to the upper position of the casting on the DISA vertical molding line, and the bottom region corresponds to the lower position of the casting on the DISA vertical molding line. The shape of the cavity is designed according to the product drawings of the clutch adjusting ring to ensure that the cast blank has accurate profile dimensions.

[0023] During the mold design phase, a reverse ellipticity compensation amount is preset in the radial direction of the cavity. This compensation amount is distributed along a sinusoidal curve along the circumference of the cavity, with the projection direction of the sprue centerline onto the radial plane of the cavity as the 0° reference. The compensation amount is largest at 0° and 180°, and smallest at 90° and 270°. By presetting this reverse ellipticity compensation amount, the elliptical deformation caused by uneven circumferential shrinkage during the solidification and cooling process of the casting can be actively counteracted during the mold design phase, thereby significantly improving the roundness qualification rate of the casting.

[0024] Gating system setup steps In the gating system setup step, a side-bottom thin-edge annular gating system is set up. This gating system includes a sprue, a side-bottom thin-edge annular ingate, a runner, and a bottom-pouring ingate.

[0025] The sprue is located on the side of the mold cavity and is used to introduce molten metal from the ladle into the gating system. The upper end of the sprue is connected to the pouring cup, and the lower end is connected to the runner.

[0026] The side-mounted thin-edge annular ingate is located at the lower side edge of the mold cavity and extends circumferentially along the cavity. The cross-section of the side-mounted thin-edge annular ingate is flat and thin, a design that allows the molten metal to enter the cavity smoothly in a thin-sheet flow pattern, effectively reducing turbulence and air entrapment, and achieving stable laminar flow filling. The circumferential extension of the side-mounted thin-edge annular ingate ensures uniform distribution of the molten metal along the circumference of the casting, avoiding localized overheating and flow deviation caused by single-point pouring. The vertical distance between the centerline of the side-mounted thin-edge annular ingate and the lowest point of the cavity is 5%-15% of the total cavity height. Positioning the ingate within this height range ensures that the molten metal enters from near the lowest point of the cavity, achieving stable bottom-up filling and facilitating the formation of a temperature gradient for sequential solidification. The circumferential extension angle of the side-mounted thin-edge annular ingate is 120°-270°. The chosen extension angle ensures sufficient coverage of the ingate in the circumferential direction of the annular casting, guaranteeing uniform circumferential distribution of molten metal while preventing excessive ingate extension that would result in an overly large gating system. The thickness of the side-mounted thin-edged annular ingate is 0.2-0.4 times the casting wall thickness, and its width is 5-15 times the thickness. This thickness-to-width ratio ensures the ingate has sufficient cross-sectional area to guarantee filling speed while maintaining a flat, thin-plate cross-sectional shape for smooth filling.

[0027] The horizontal sprue is located at the bottom of the cavity and is used to distribute the molten metal introduced by the sprue to the side thin-edged annular ingate and the bottom-pour ingate.

[0028] The bottom-pour ingate is connected to the bottom of the mold cavity. Together with the side-mounted thin-edged annular ingate, the bottom-pour ingate forms a dual-path gating system. The side-mounted thin-edged annular ingate handles the primary pouring task, while the bottom-pour ingate handles the auxiliary pouring task. The bottom-pour ingate allows for the replenishment of molten metal from the bottom during the later stages of pouring, helping to guide the final solidified shrinkage cavities towards the riser.

[0029] Compensation system setup steps In the feeding system setup step, an annular hot riser is provided at the top of the cavity. The annular hot riser extends circumferentially along the cavity, and multiple riser necks are provided on the inner wall of the annular hot riser, which are evenly distributed circumferentially, and each riser neck is connected to the top of the cavity.

[0030] The annular hot riser extends circumferentially along the cavity, enabling it to uniformly feed the casting around its entire circumference. This overcomes the limitations of traditional single risers, which have limited feeding distance and cannot cover the entire annular area. Multiple riser necks are evenly distributed circumferentially, each serving as a channel for molten metal to flow from the annular hot riser to the top of the cavity, ensuring that the feeding molten metal is evenly supplied to all parts of the top of the casting.

[0031] The annular hot riser extends circumferentially along the mold cavity at an angle of 270°-360°. The annular hot riser has sufficient circumferential coverage to ensure complete feeding to the top of the casting. When the extension angle is 360°, the annular hot riser forms a complete annular structure. The width of the annular hot riser is 1.5-3 times the casting wall thickness, and the height is 2-4 times the casting wall thickness. This size ratio ensures that the annular hot riser has sufficient liquid storage volume and feeding pressure, providing ample molten metal replenishment for the solidification shrinkage of the casting. There are 3-8 riser necks. The riser neck has a trapezoidal cross-section, with the upper base width being 0.5-0.8 times the lower base width. The trapezoidal cross-section design ensures unobstructed feeding channels while facilitating subsequent cutting and separation operations; the narrower upper and wider lower structure promotes the downward flow of feeding molten metal.

[0032] The annular hot riser is covered by an insulating sleeve. The sleeve is 5-15mm thick, and an air-insulating gap, 2-6mm wide, is provided between the inner wall of the sleeve and the outer wall of the annular hot riser. This double-layer insulation structure of the sleeve and the air-insulating gap effectively prolongs the solidification time of the molten metal in the annular hot riser, improves feeding efficiency, and ensures that the riser maintains its feeding capacity until the casting is completely solidified.

[0033] Pouring control steps In the pouring control step, molten metal is poured into the mold cavity through the sprue. During the pouring process, the side-bottom thin-edged annular ingate is controlled to start pouring before the bottom-pour ingate, and the pouring volume of the side-bottom thin-edged annular ingate is greater than that of the bottom-pour ingate.

[0034] The side-mounted thin-edged annular ingate begins pouring before the bottom-pour ingate, allowing molten metal to enter the cavity from the lower side edge first, forming an initial molten metal cushion at the bottom of the cavity. This cushion buffers the impact of molten metal entering subsequently from the bottom-pour ingate, reducing splashing and turbulence. The pouring volume of the side-mounted thin-edged annular ingate is greater than that of the bottom-pour ingate, ensuring that during the initial and middle stages of pouring, the molten metal enters the cavity uniformly circumferentially through the side-mounted thin-edged annular ingate, achieving smooth filling.

[0035] The side-mounted thin-edged annular ingate begins pouring 0.5-2 seconds before the bottom-pour ingate. This time difference ensures that the side-mounted ingate prioritizes establishing the initial molten metal cushion layer, while preventing the bottom-pour ingate from starting too late and affecting the integrity of the filling process due to an excessively long time difference. The side-mounted thin-edged annular ingate accounts for 65%-80% of the total pouring volume, while the bottom-pour ingate accounts for 20%-35%. By controlling the side-mounted thin-edged annular ingate to handle the main pouring volume and the bottom-pour ingate to handle the auxiliary pouring volume, both the stability and circumferential uniformity of the initial filling stage are ensured, as well as sufficient supply for bottom feeding in the later stages of pouring.

[0036] When the molten metal level in the mold cavity rises to 60%-80% of the cavity height, the pouring speed of the side-mounted thin-edged annular ingate is reduced, while the pouring speed of the bottom-mounted ingate is increased. This dynamic switching control is implemented in the mid-to-late stages of the filling process, when most of the cavity volume has been filled with molten metal. Continuing to primarily pour using the side-mounted thin-edged annular ingate may lead to excessively high temperatures in the top molten metal, which is detrimental to sequential solidification. By reducing the pouring speed of the side-mounted thin-edged annular ingate and increasing the pouring speed of the bottom-mounted ingate, the main pouring task in the later stages of filling is switched from side-mounted pouring to bottom-mounted pouring. Utilizing the top-supporting and shrinkage-compensating effect of the bottom-mounted ingate, the last solidified shrinkage cavity is guided towards the annular hot riser, while avoiding overheating of the top molten metal. The reduction in the pouring speed of the side-mounted thin-edged annular ingate and the increase in the pouring speed of the bottom-mounted ingate can be achieved using a linear variation, ensuring a smooth transition in pouring speed and avoiding instability caused by sudden speed changes.

[0037] Partitioned cooling steps In the partitioned cooling step, the top and bottom regions of the cavity are subjected to differentiated cooling control, so that a sequential solidification temperature gradient is formed from bottom to top along the height direction of the cavity.

[0038] Specifically, the cooling rate is slowed down in the top region of the cavity and accelerated in the bottom region. By employing different cooling strategies for the top and bottom regions, the bottom of the cavity solidifies first, and the top solidifies last, forming a sequential solidification temperature gradient from bottom to top. This sequential solidification temperature gradient, combined with the top feeding of the annular hot riser, ensures that the casting is consistently replenished with molten metal from the top annular hot riser during solidification, thereby effectively eliminating shrinkage porosity and shrinkage defects.

[0039] In the zoned cooling process, an insulation layer is placed in the top region of the cavity to slow down the cooling rate, while heat sinks are placed in the bottom region to accelerate the cooling rate. The heat sinks are evenly distributed circumferentially along the cavity, with 4-8 sinks in total. The insulation layer delays heat loss from the top region, extending the time the molten metal remains liquid and providing sufficient time for the annular hot riser to fill the gap. The heat sinks accelerate heat loss from the bottom region, causing the molten metal to solidify first, forming the starting point for sequential solidification. The combined use of the insulation layer and heat sinks allows for precise control of the temperature gradient along the height of the cavity, ensuring successful sequential solidification.

[0040] Unpacking and Sand Removal Steps In the unpacking and sand removal step, the casting is unpacked and removed from the sand mold after cooling and solidification to obtain the clutch adjusting ring casting. The cooling time of the casting in the sand mold should be greater than 1 hour to ensure that the casting has fully solidified and cooled to a suitable temperature for unpacking. After unpacking, the casting is shot-blasted to remove surface sand, followed by gating and grinding of the risers and gates.

[0041] The chemical composition of the molten metal, by mass percentage, is: C 3.20%-3.50%, Si 1.90%-2.30%, Mn 0.60%-0.90%, P≤0.15%, S≤0.15%, with the balance being Fe and unavoidable impurities. The pouring temperature of the molten metal is 1420±40℃, and the tapping temperature is 1500±40℃. This temperature range ensures good fluidity of the molten metal, allowing it to smoothly fill all parts of the mold cavity, while avoiding defects such as sand adhesion due to excessively high temperatures or incomplete filling due to excessively low temperatures. The sand mold has a hardness greater than or equal to 85B, and its thickness is 170-230mm. Controlling the hardness and thickness of the sand mold ensures sufficient strength and rigidity to withstand the static pressure and impact of the molten metal, guaranteeing the dimensional accuracy of the casting.

[0042] Calculation principle of anti-ellipticity compensation The formula for calculating the anti-ellipticity compensation is: ,in This is the maximum anti-ellipticity compensation amount. It is an empirical coefficient and its value ranges from 0.3 to 0.8. For the nominal diameter of the casting, is the coefficient of linear expansion of the material. This is the solidification temperature difference.

[0043] The physical principle behind this formula is as follows: During the cooling process from the pouring temperature to room temperature, the casting undergoes thermal shrinkage, the theoretical shrinkage being determined by the nominal diameter of the casting. Coefficient of linear expansion of materials and solidification temperature difference The product of these factors determines the actual shrinkage. However, the actual shrinkage of castings is not free shrinkage, but is limited by various factors such as sand mold resistance, casting structure constraints, and uneven cooling. Therefore, the actual deformation compensation is usually less than the theoretical free shrinkage, and needs to be determined by empirical coefficients. Make corrections. A value of 0.3-0.8 indicates that the actual compensation is 30%-80% of the theoretical free shrinkage. This range is physically reasonable because the mold restricts the free shrinkage of the casting.

[0044] In practical applications, for a specific specification of adjusting ring casting, the first step is to determine the nominal diameter of the casting. Coefficient of linear expansion of materials and solidification temperature difference Calculate the theoretical shrinkage, and then, considering the casting process characteristics of this product specification, select an appropriate shrinkage within the range of 0.3-0.8. The value is used to calculate the maximum inverse ellipticity compensation amount. The maximum anti-ellipticity compensation amount The maximum compensation values ​​corresponding to the 0° and 180° directions of the cavity are distributed along the circumference of the cavity according to a sine curve, decreasing to the minimum compensation values ​​in the 90° and 270° directions. Through the above calculation and distribution method, quantitative and direction-specific pre-set compensation for the elliptical deformation of the casting is achieved, effectively improving the roundness qualification rate of the casting.

[0045] During trial production, actual ellipticity data of the test castings were collected using a 3D scanner. This data was then compared to the target ellipticity to calculate the ellipticity deviation. This deviation was used as feedback to adjust the empirical coefficients. Perform online corrections until the ovality deviation of the trial casting converges to within ±0.05 mm. Then, apply the corrected... The value is fixed as the production coefficient for that batch of products. This online correction mechanism allows for adjustments to the ring castings of different batches and specifications. The value is precisely calibrated to ensure the accuracy of the anti-ellipticity compensation, thereby further improving product consistency.

[0046] Example 1 Taking the C95 adjusting ring as an example, DISA vertical molding lines are used for wet sand molding. Nominal diameter of the casting. The diameter is 330mm, and the casting wall thickness is 8mm. The shape of the cavity matches the C95 adjusting ring, and the cavity has a top area and a bottom area.

[0047] In the mold preparation step, a reverse ellipticity compensation amount is preset in the radial direction of the cavity during the mold design stage. This reverse ellipticity compensation amount is distributed sinusoidally along the circumference of the cavity, with the projection direction of the sprue centerline in the radial plane of the cavity as the 0° reference. The compensation amount is maximum in the 0° and 180° directions and minimum in the 90° and 270° directions. The nominal diameter of the C95 adjusting ring casting is used as the reference. =330mm, coefficient of linear expansion of material =1.2× / ℃, solidification temperature difference =600℃, select empirical coefficient =0.5, the maximum inverse ellipticity compensation amount is calculated. =0.5×330×1.2× ×600≈1.19mm. This maximum anti-ellipticity compensation of 1.19mm corresponds to the compensation values ​​in the 0° and 180° directions of the cavity, and transitions along the circumference of the cavity to the 0mm compensation values ​​in the 90° and 270° directions according to a sine curve.

[0048] In the gating system setup step, a side-bottom thin-edge annular gating system is configured. The vertical distance between the centerline of the side-bottom thin-edge annular ingate and the lowest point of the cavity is 10% of the total cavity height, i.e., 33 mm. The cross-section of the side-bottom thin-edge annular ingate is a flat, thin sheet with a thickness of 0.3 times the casting wall thickness, i.e., 2.4 mm, and a width of 10 times the thickness, i.e., 24 mm. The side-bottom thin-edge annular ingate extends circumferentially along the cavity at an angle of 200°.

[0049] In the feeding system setup step, an annular hot riser is installed at the top of the mold cavity. The annular hot riser extends 330° circumferentially around the mold cavity. The width of the annular hot riser is twice the casting wall thickness, i.e., 16 mm, and the height is three times the casting wall thickness, i.e., 24 mm. Six riser necks are evenly distributed circumferentially on the inner wall of the annular hot riser. Each riser neck has a trapezoidal cross-section, with the upper base width being 0.6 times the lower base width.

[0050] In the pouring control process, the side-mounted thin-edge annular ingate begins pouring 1 second before the bottom-pour ingate. The pouring volume of the side-mounted thin-edge annular ingate accounts for 72% of the total pouring volume, while the pouring volume of the bottom-pour ingate accounts for 28%. When the molten metal level in the cavity rises to 70% of the cavity height, the pouring speed of the side-mounted thin-edge annular ingate decreases linearly, while the pouring speed of the bottom-pour ingate increases linearly accordingly.

[0051] In the partitioned cooling step, an insulation layer is set in the top area of ​​the cavity to slow down the cooling rate of the top area, and six heat sinks are set in the bottom area of ​​the cavity to accelerate the cooling rate of the bottom area, so that a sequential solidification temperature gradient is formed from bottom to top along the height direction of the cavity.

[0052] The chemical composition of the molten metal, by mass percentage, is: carbon 3.33%, silicon 2.21%, manganese 0.80%, phosphorus 0.029%, sulfur 0.070%, with the balance being iron and unavoidable impurities. The pouring temperature of the molten metal is 1430℃, and the tapping temperature is 1510℃. The sand mold has a hardness of 88B and a thickness of 200mm. The cooling time of the casting in the sand mold is 1.5 hours.

[0053] The C95 adjusting ring castings obtained by the above method, after X-ray inspection and evaluation according to the GB / T5677-2018 standard (Grade A), all met the Grade 1 quality standard, with no shrinkage cavities or porosity defects. The casting hardness ranged from HB197 to 213, and the tensile strength was 253 MPa, meeting the requirements of the SAE G3000 standard. The ovality of the castings was controlled within 0.3 mm, and all critical dimensions met the drawing tolerances.

[0054] Example 2 The difference between this embodiment and Embodiment 1 is that, taking the C98 adjusting ring as an example, the nominal diameter of the casting... The diameter is 310mm, and the wall thickness of the casting is 7.5mm. In the mold preparation step, according to... =310mm, =580℃, select empirical coefficient =0.55, the maximum inverse ellipticity compensation amount is calculated. =0.55×310×1.2× ×580≈1.19mm. In the gating system setup step, the vertical distance between the centerline of the side-bottom thin-edge annular ingate and the lowest point of the cavity is 8% of the total cavity height. The thickness of the side-bottom thin-edge annular ingate is 0.25 times the casting wall thickness, and its width is 12 times the thickness. The circumferential extension angle of the side-bottom thin-edge annular ingate along the cavity is 180°. In the feeding system setup step, the annular hot riser extends circumferentially along the cavity at an angle of 300°, its width is 2.5 times the casting wall thickness, its height is 3.5 times the casting wall thickness, and the number of riser necks is 5. In the pouring control step, the side-bottom thin-edge annular ingate begins pouring 1.2 seconds before the bottom-pour ingate. The pouring volume of the side-bottom thin-edge annular ingate accounts for 68% of the total pouring volume, and the pouring volume of the bottom-pour ingate accounts for 32% of the total pouring volume. The liquid level switching height is 65% of the cavity height. In the zoned cooling step, five heat sinks were used. The pouring temperature of the molten metal was 1410℃, the tapping temperature was 1490℃, the sand mold hardness was 87B, and the sand mold thickness was 190mm. The C98 adjusting ring castings obtained by the above method all met the Class 1 quality standard in X-ray inspection, the ovality of the castings was controlled within 0.3mm, and all critical dimensions met the drawing tolerances.

[0055] Example 3 The difference between this embodiment and Embodiment 1 is as follows: the vertical distance between the centerline of the side-mounted thin-edged annular ingate and the lowest point of the cavity is 5% of the total cavity height; the thickness of the side-mounted thin-edged annular ingate is 0.4 times the casting wall thickness; the extension angle is 120°; and the pouring volume of the side-mounted thin-edged annular ingate accounts for 80% of the total pouring volume. The annular hot riser extends circumferentially around the cavity at an angle of 270°, its width is 1.5 times the casting wall thickness, its height is 2 times the casting wall thickness, and there are 3 riser necks. The pouring temperature of the molten metal is 1380℃, and the tapping temperature is 1460℃. Implementation results: X-ray inspection showed all samples met Level 1 quality standards; the dimensional accuracy of the castings met the drawing requirements; and the mechanical properties conformed to the SAE G3000 standard.

[0056] Example 4 The difference between this embodiment and Embodiment 1 is as follows: the vertical distance between the centerline of the side-mounted thin-edged annular ingate and the lowest point of the cavity is 15% of the total cavity height; the thickness of the side-mounted thin-edged annular ingate is 0.2 times the casting wall thickness; the extension angle is 270°; and the pouring volume of the side-mounted thin-edged annular ingate accounts for 65% of the total pouring volume. The annular hot riser extends 360° circumferentially along the cavity, with a width three times the casting wall thickness and a height four times the casting wall thickness. There are eight riser necks. The pouring temperature of the molten metal is 1460℃, and the tapping temperature is 1540℃. Implementation results: X-ray inspection showed all samples met Level 1 quality standards; the dimensional accuracy of the castings met the drawing requirements; and the mechanical properties conformed to the SAE G3000 standard.

[0057] In summary, the side-thin-edge annular casting method for the clutch adjusting ring provided in this invention achieves stable and rapid low-level filling and active temperature field control in the later stages of casting by setting the side-thin-edge annular ingate at the lower edge of the cavity with a flat, thin cross-section, combining the timing and flow distribution of pouring before bottom-pouring ingate with a dominant pouring volume, and the dynamic switching of decreasing side-pouring speed and increasing bottom-pouring speed when the liquid level rises to 60%-80% of the cavity height. This effectively avoids air entrapment, sand flushing, and top overheating. The annular hot riser extends circumferentially and is equipped with multiple evenly distributed riser necks, which, together with the zoned cooling control of top insulation and bottom heat dissipation, form a sequential solidification temperature gradient from bottom to top, ensuring uniform circumferential shrinkage and eliminating shrinkage porosity defects. During the mold design stage, a sinusoidally distributed anti-ellipticity compensation amount is preset along the circumference of the cavity, which actively compensates for the elliptical deformation caused by uneven solidification shrinkage, significantly improving the roundness of the casting. The above-mentioned technical means organically unify the filling, feeding and deformation control, so that the dimensional accuracy and internal quality of the castings are improved simultaneously, and the product consistency is good.

[0058] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for casting a clutch adjusting ring with a thin side edge, employing DISA vertical molding lines for wet sand molding, characterized in that... Includes the following steps: Casting preparation steps: Provide a casting cavity, the shape of which matches the clutch adjusting ring, the cavity having a top region and a bottom region; Gating system setup steps: Set up a gating system, which includes a sprue, a side-mounted thin-edged annular ingate, a horizontal runner, and a bottom-ingate. The side-mounted thin-edged annular ingate is located at the lower side edge of the cavity and extends circumferentially along the cavity. The bottom-ingate is connected to the bottom of the cavity. The cross-section of the side-mounted thin-edged annular ingate is a flat, thin sheet. Feeding system setup steps: An annular hot riser is set at the top of the cavity. The annular hot riser extends circumferentially along the cavity, and multiple riser necks are evenly distributed circumferentially on the inner wall of the annular hot riser. Each riser neck is connected to the top of the cavity. Pouring control steps: Molten metal is poured into the cavity through the sprue, and the side-bottom thin-edge annular ingate is controlled to start pouring before the bottom-pour ingate, and the pouring volume of the side-bottom thin-edge annular ingate is greater than that of the bottom-pour ingate; when the molten metal level in the cavity rises to 60%-80% of the cavity height, the pouring speed of the side-bottom thin-edge annular ingate is controlled to decrease, while the pouring speed of the bottom-pour ingate is controlled to increase. Partitioned cooling step: Differentiated cooling control is applied to the top and bottom regions of the cavity to create a sequential solidification temperature gradient from bottom to top along the height direction of the cavity; Unpacking and sand removal steps: After cooling and solidification, unpack and remove the sand to obtain the clutch adjusting ring casting.

2. The method for casting a thin-edged annular side of a clutch adjusting ring according to claim 1, characterized in that, The vertical distance between the centerline of the lower side thin-edged annular ingate and the lowest point of the cavity is 5%-15% of the total height of the cavity.

3. The method for casting a thin-edged annular side of a clutch adjusting ring according to claim 1, characterized in that, The side-below thin-edged annular ingate extends circumferentially along the cavity at an angle of 120°-270°. The thickness of the side-below thin-edged annular ingate is 0.2-0.4 times the thickness of the casting wall, and the width is 5-15 times the thickness.

4. The side thin-edge annular casting method for a clutch adjusting ring according to claim 1, characterized in that, In the pouring control step, the side-bottom thin-edge annular ingate starts pouring 0.5-2 seconds before the bottom-pour ingate; the pouring volume of the side-bottom thin-edge annular ingate accounts for 65%-80% of the total pouring volume, and the pouring volume of the bottom-pour ingate accounts for 20%-35% of the total pouring volume.

5. The method for casting a thin-edged annular side of a clutch adjusting ring according to claim 1, characterized in that, The annular hot riser extends circumferentially along the cavity at an angle of 270°-360°. The width of the annular hot riser is 1.5-3 times the thickness of the casting wall, and the height is 2-4 times the thickness of the casting wall. The number of riser necks is 3-8, and the cross-section of each riser neck is trapezoidal, with the width of the upper base being 0.5-0.8 times the width of the lower base.

6. The method for casting a thin-edged annular side of a clutch adjusting ring according to claim 1, characterized in that, In the mold preparation step, during the mold design stage, a reverse ellipticity compensation amount is preset in the radial direction of the cavity, and the reverse ellipticity compensation amount is distributed in a sinusoidal curve along the circumference of the cavity.

7. A method for casting a clutch adjusting ring with a thin side edge according to claim 6, characterized in that, With the projection direction of the center line of the sprue in the radial plane of the cavity as the 0° direction reference, the anti-ellipticity compensation is the largest in the 0° and 180° directions of the cavity, and the smallest in the 90° and 270° directions.

8. A method for casting a thin-edged annular side of a clutch adjusting ring according to claim 6, characterized in that, The formula for calculating the anti-ellipticity compensation amount is: ,in This is the maximum anti-ellipticity compensation amount. It is an empirical coefficient and its value ranges from 0.3 to 0.

8. For the nominal diameter of the casting, is the coefficient of linear expansion of the material. This is the solidification temperature difference.

9. A method for casting a thin-edged annular side of a clutch adjusting ring according to claim 1, characterized in that, The outer side of the annular hot riser is covered with an insulating sleeve, and an air insulation gap is provided between the inner wall of the insulating sleeve and the outer wall of the annular hot riser; in the partitioned cooling step, an insulating layer is provided in the top area of ​​the cavity, and heat dissipation fins are provided in the bottom area of ​​the cavity, and the heat dissipation fins are evenly distributed circumferentially.

10. A method for casting a thin-edged annular side of a clutch adjusting ring according to claim 1, characterized in that, The chemical composition of the molten metal, by mass percentage, is: C 3.20%-3.50%, Si 1.90%-2.30%, Mn 0.60%-0.90%, P≤0.15%, S≤0.15%, with the balance being Fe and unavoidable impurities; the pouring temperature of the molten metal is 1420±40℃, and the tapping temperature is 1500±40℃; the hardness of the sand mold is ≥85B type, and the thickness of the sand mold is 170-230mm.

Images