Integral air spring air chamber low-pressure casting process

Abstract

The invention relates to an integrated air spring air chamber low-pressure casting process which comprises the following specific steps: S1, a thin-wall hollow integrated structure is adopted, the wall thickness of a main body is 4 mm, and local mounting points are transited to 6-8 mm through a gradually-changed thickening design; a pouring system is designed according to the air spring structure, and the design that four parts are arranged at one pouring gate is adopted; s2, the inner cavity is formed by combining two sand cores, the two sand cores are the first sand core and the second sand core, and the inner cavity is formed between the first sand core and the second sand core; s3, the mold adopts an upper and lower mold parting structure; s4, the sand core is positioned in the X direction, the Y direction and the Z direction; s5, a plurality of cooling water channels are embedded in the hot spot area of the mold; s6, die exhaust channels are arranged at the molten aluminum intersection and the high point of a cavity, and three ejector rods are designed in total and evenly distributed in a non-key pressure-bearing area; and S7, setting process parameters of field production. By optimizing mold design, a pouring system and technological parameters, integrated forming of the air spring air chamber is achieved, and the weight is remarkably reduced while the product performance is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of automobile parts manufacturing, in particular to a low-pressure casting process for an integral air spring chamber. Background Art

[0002] With the rapid development of lightweight automotive technology, aluminum alloys are increasingly being used in chassis components. As a core component of the automotive suspension system, the performance of air springs directly impacts the comfort and handling of the vehicle. Traditional air spring chambers often utilize a split structure, assembled from multiple components through welding or bolting. This structure often suffers from the following disadvantages: 1. Heavy weight: The multi-component assembly requires increased material usage for the connection structure; 2. Poor sealing: Welded or bolted connections are prone to leakage, impacting air spring performance; 3. Stress concentration: The connection is prone to fatigue cracking under long-term alternating loads; 4. Complex manufacturing: Split-part manufacturing requires multiple steps and is costly.

[0003] Currently, some manufacturers attempt to use casting to manufacture hollow spring chambers. However, due to the complex structure and uneven wall thickness, defects such as shrinkage and porosity are prone to occur, affecting product strength and sealing. Therefore, an optimized low-pressure casting process is urgently needed to achieve high-quality, integrated molding of hollow spring chambers. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a low-pressure casting process for an integral air spring air chamber. By optimizing the mold design, pouring system and process parameters, the integrated molding of the air spring air chamber is achieved, which significantly reduces the weight while ensuring product performance.

[0005] The technical solution adopted by the present invention to solve the technical problem is to provide a low-pressure casting process for an integral hollow spring air chamber, including the following specific steps:

[0006] S1. It adopts a thin-walled hollow integrated structure with a main wall thickness of 4mm. The local installation points are gradually thickened to 6-8mm. The pouring system is designed according to the hollow spring structure, and a one-gate-four-piece design is adopted to improve the mass production cycle and process yield. A main runner is set between the gate and each air chamber. The main runner is set at the bottom. A high-position riser is set on the top of each air chamber. The high-position riser is connected to the thick hot zone area through a shrinkage channel.

[0007] S2. The internal cavity is formed by combining two sand cores, namely sand core 1 and sand core 2. The internal cavity is formed between sand core 1 and sand core 2. Sand core 1 and sand core 2 are assembled together by a concave-convex combination structure to prevent the sand core from shifting;

[0008] S3. The mold adopts an upper and lower mold parting structure, with the upper mold accounting for 80%-85% and the lower mold accounting for 15%-20%. The parting line adopts a continuous curved surface transition to avoid sharp corners.

[0009] S4. The sand core adopts XYZ three-axis positioning, which are X positioning, Y positioning and Z positioning respectively. The Z positioning is supported by the bottom plane to ensure the cavity size accuracy;

[0010] S5. Multiple cooling water channels are embedded in the hot zone of the mold;

[0011] S6. The mold exhaust channel is set at the intersection of aluminum liquid and the high point of the cavity. A total of 3 ejector pins are designed, evenly distributed in non-critical pressure-bearing areas;

[0012] S7. Setting of process parameters for on-site production: Aluminum liquid treatment: A356.2 aluminum alloy is used, and the hydrogen content after refining is ≤0.15ml / 100g; liquid rising stage: pressure 125mbar, speed 25mbar / s, time 5s; filling stage: pressure 165mbar, speed 10mbar / s, time 4s; pressurization stage: pressure 226mbar, speed 30.5mbar / s, time 2s; pressure holding stage: pressure 226mbar, time 170s.

[0013] As a supplement to the technical solution described in the present invention, in the above S1, the pouring system is entirely designed on the processing surface, and no pouring system features will appear on the finished product.

[0014] As a supplement to the technical solution described in the present invention, in S2, the concave-convex combination structure between the sand core 1 and the sand core 2 adopts a mortise and tenon fitting method, and the sand core positioning accuracy is ±0.1mm.

[0015] As a supplement to the technical solution described in the present invention, in the S5, there are two cooling water channels, which are V-shaped and have a diameter of 14 mm. The cooling water flow rate inside the cooling water channel is ≥3 L / min, and the mold temperature gradient is ≤15°C, ensuring uniform cooling of the hot zone area.

[0016] As a supplement to the technical solution described in the present invention, in the S6, the exhaust channel adopts a stepped structure to reduce the risk of aluminum liquid backflow.

[0017] Beneficial effects: The present invention relates to a low-pressure casting process for an integral hollow spring air chamber, which achieves lightweighting through integrated molding design, and optimizes the shrinkage feeding system, cooling system and sand core positioning scheme to ensure that the product has excellent mechanical properties and sealing; by optimizing the mold design, pouring system and process parameters, the integrated molding of the hollow spring air chamber is achieved, which significantly reduces the weight while ensuring product performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of the integral hollow spring air chamber pouring system of the present invention;

[0019] Figure 2 is a cross-sectional view of an example of a modular sand core of the present invention;

[0020] Figure 3 Schematic diagram of the positioning structure of the sand core of the present invention;

[0021] Figure 4 Schematic diagram of the cooling position of the mold body according to an example of the present invention. DETAILED DESCRIPTION

[0022] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.

[0023] The embodiment of the present invention relates to a low-pressure casting process for an integral hollow spring air chamber, such as Figure 1-4 As shown, the following specific steps are included:

[0024] S1. It adopts a thin-walled hollow integrated structure with a main wall thickness of 4mm. The local installation points are gradually thickened to 6-8mm. The casting system is designed according to the hollow spring structure, and a one-gate 9-out-of-four design is adopted to improve the mass production cycle and process yield. A main runner 1, 2, 3, 4 is set between the gate 9 and each air chamber. The main runners 1, 2, 3, 4 are set at the bottom position. A high-position riser 5, 6, 7, 8 is set on the top of each air chamber. The high-position risers 5, 6, 7, 8 are connected to the thick hot zone area through the shrinkage channel 9. The casting system is designed entirely on the processing surface. No casting system features will appear on the finished product, ensuring the integrity of the parts.

[0025] S2. The internal cavity is formed by combining two sand cores, namely sand core 10 and sand core 2 11. The internal cavity is formed between sand core 10 and sand core 2 11. Sand core 10 and sand core 2 11 are assembled together by a concave-convex combination structure 12 to prevent the sand cores from shifting;

[0026] S3. The mold adopts an upper and lower mold parting structure, with the upper mold accounting for 80%-85% and the lower mold accounting for 15%-20%. The parting line adopts a continuous curved surface transition to avoid sharp corners.

[0027] S4, sand core adopts XYZ three-axis positioning, XYZ three-axis positioning is X positioning 13, Y positioning 14 and Z positioning 16 respectively, Z positioning 16 is supported by the bottom plane to ensure the cavity size accuracy;

[0028] S5. Multiple cooling water channels 17 and 18 are embedded in the hot zone of the mold;

[0029] S6. The mold exhaust channel is set at the intersection of aluminum liquid and the high point of the cavity. A total of 3 ejector pins are designed, evenly distributed in non-critical pressure-bearing areas;

[0030] S7. Setting of process parameters for on-site production: Aluminum liquid treatment: A356.2 aluminum alloy is used, and the hydrogen content after refining is ≤0.15ml / 100g; liquid rising stage: pressure 125mbar, speed 25mbar / s, time 5s; filling stage: pressure 165mbar, speed 10mbar / s, time 4s; pressurization stage: pressure 226mbar, speed 30.5mbar / s, time 2s; pressure holding stage: pressure 226mbar, time 170s.

[0031] As a preferred solution, in the above S2, the concave-convex combination structure 12 between the sand core 10 and the sand core 2 11 adopts a mortise and tenon joint fitting method, and the sand core positioning accuracy is ±0.1mm.

[0032] As a preferred solution, in the S5, there are two cooling water channels 17 and 18, which are V-shaped structures. The diameter of the cooling water channels 17 and 18 is 14 mm. The cooling water flow rate inside the cooling water channels 17 and 18 is ≥3 L / min, and the mold temperature gradient is ≤15°C, ensuring uniform cooling of the hot zone area.

[0033] As a preferred solution, in the S6, the exhaust channel adopts a stepped structure to reduce the risk of aluminum liquid backflow.

[0034] The present invention achieves lightweighting through an integrated molding design, and optimizes the shrinkage feeding system, cooling system and sand core positioning scheme to ensure that the product has excellent mechanical properties and sealing. By optimizing the mold design, casting system and process parameters, the integrated molding of the air spring air chamber is achieved, which significantly reduces the weight while ensuring product performance.

[0035] In the description of the present invention, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention; the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0036] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figures. For example, if the device in the drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0037] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0038] The above is a detailed introduction to the low-pressure casting process of an integral air spring air chamber provided by the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea; at the same time, for general technical personnel in this field, based on the ideas of the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A low-pressure casting process for an integral hollow spring air chamber, characterized in that: The specific steps include: S1. A thin-walled hollow integrated structure is adopted, with a main wall thickness of 4mm, and a local installation point transitioning to 6-8mm through a gradual thickening design; a pouring system is designed according to the hollow spring structure, and a one-gate (9) four-piece design is adopted. A main runner (1, 2, 3, 4) is provided between the gate (9) and each air chamber, and the main runner (1, 2, 3, 4) is provided at the bottom position. A high-position riser (5, 6, 7, 8) is provided on the top of each air chamber, and the high-position risers (5, 6, 7, 8) are connected to the thick and large hot section area through the shrinkage channel (9); S2. The internal cavity is formed by combining two sand cores, the two sand cores are sand core one (10) and sand core two (11), the internal cavity is formed between sand core one (10) and sand core two (11), and the sand core one (10) and sand core two (11) are assembled together by a concave-convex combination structure (12) to prevent the sand cores from shifting; S3. The mold adopts an upper and lower mold parting structure, with the upper mold accounting for 80%-85% and the lower mold accounting for 15%-20%. The parting line adopts a continuous curved surface transition to avoid sharp corners. S4, sand core adopts XYZ three-axis positioning, XYZ three-axis positioning is X positioning (13), Y positioning (14) and Z positioning (16), Z positioning (16) is supported by the bottom plane to ensure the cavity size accuracy; S5. A plurality of cooling water channels (17, 18) are embedded in the hot zone of the mold; S6. The mold exhaust channel is set at the intersection of aluminum liquid and the high point of the cavity. A total of 3 ejector pins are designed, evenly distributed in non-critical pressure-bearing areas; S7. Setting of process parameters for on-site production: Aluminum liquid treatment: A356.2 aluminum alloy is used, and the hydrogen content after refining is ≤0.15ml / 100g; liquid rising stage: pressure 125mbar, speed 25mbar / s, time 5s; filling stage: pressure 165mbar, speed 10mbar / s, time 4s; pressurization stage: pressure 226mbar, speed 30.5mbar / s, time 2s; pressure holding stage: pressure 226mbar, time 170s.

2. The low-pressure casting process for an integral hollow spring air chamber according to claim 1, characterized in that: In the above-mentioned S1, the gating system is entirely designed on the processing surface, and no gating system features will appear on the finished product.

3. The low-pressure casting process for an integral hollow spring air chamber according to claim 1, characterized in that: In the aforementioned S2, the concave-convex combination structure (12) between the sand core 1 (10) and the sand core 2 (11) adopts a mortise and tenon joint fitting method, and the positioning accuracy of the sand core is ±0.1 mm.

4. The low-pressure casting process for an integral hollow spring air chamber according to claim 1, characterized in that: In the S5, there are two cooling water channels (17, 18), which are V-shaped. The diameter of the cooling water channels (17, 18) is 14 mm. The cooling water flow rate inside the cooling water channels (17, 18) is ≥3 L / min, and the mold temperature gradient is ≤15°C, ensuring uniform cooling of the hot zone area.

5. The low-pressure casting process for an integral hollow spring air chamber according to claim 1, characterized in that: In the S6, the exhaust channel adopts a stepped structure to reduce the risk of aluminum liquid backflow.

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