RPS steering gear shell die-casting process

Abstract

The invention relates to an RPS steering gear shell die-casting technology. The technology comprises the following steps that S1, early-stage work preparation is conducted, wherein die design and pouring and discharging system design are included; s2, determining a die-casting water cooling process; s3, die-casting production; s4, demolding; by reasonably designing the die and the process, application of the RPS complex shell in the die-casting process is achieved, compared with traditional gravity casting, molten metal is pushed by an injection punch, the higher-speed mold filling and high-pressure solidification process is completed, and the ideal product internal quality is obtained; the ADC12 aluminum alloy automobile steering system castings with unequal wall thicknesses and complex structures are produced through the method, and the defects of air holes, shrinkage cavities in hot spots and the like caused by air entrapment in the high-speed filling process are effectively overcome.

Description

Technical Field

[0001] The invention belongs to the technical field of steering gear housing manufacturing and relates to a RPS steering gear housing die-casting process. Background Art

[0002] The steering gear housing is the core component of the steering gear assembly. It is the load-bearing and safety performance guarantee. It is the core link from the steering wheel to the bridge of the car, and an important component to ensure safety, stability and accuracy. Compared with other types of electric power steering housings, RPS has the fastest response speed and the highest precision. Its casting structure is more complex, and the internal quality requirements of the casting are higher. The casting is difficult, and the process mostly adopts die casting or gravity casting.

[0003] The existing RPS shell has a complex structure, uneven wall thickness, multiple and scattered heat nodes, and is prone to casting defects such as pores, shrinkage holes, and cold shuts. The casting processability is poor, and molding and batch production are difficult. Summary of the invention

[0004] The purpose of the present invention is to solve the above problems in the prior art and to propose a die-casting process for an RPS steering gear housing.

[0005] The object of the present invention can be achieved by the following technical solutions: A RPS steering gear housing die-casting process comprises the following steps: S1: Preliminary work preparation: including mold design and pouring system design; S2: Determination of die casting water cooling process; S3: Die casting production; Die casting production includes: S31, slow filling stage, pushing the aluminum liquid to flow smoothly to the gate; S32, fast filling stage, aluminum liquid is pushed by the punch to fill the RPS shell cavity at high speed, and the gas in the cavity is discharged through the design of reasonable slag bag and exhaust to avoid gas entrapment and ensure good internal quality; S33, pressurization stage; after the aluminum liquid fills the cavity, the punch applies a pressure of 80-100MPa to compact the casting to ensure the density and high strength of the RPS shell; S34, curing stage, after a period of curing, the product is fully formed; S4: demoulding; separating the movable mold assembly from the fixed mold assembly; driving the core pulling rod to separate from the product cavity through two core pulling mechanisms; driving the locking block and the lower slider to separate through the lower slider; driving the upper slider and the lower slider to separate from the side wall of the steering gear through the upper slider and the lower slider mechanism.

[0006] In the above-mentioned RPS steering gear housing die-casting process, the water cooling process adopts local spot cooling to control the mold temperature and thermal effects. The water cooling starts after the injection is completed and is maintained for 20-30 seconds; the cooling water pressure is 0.4-0.6Mpa, and the flow rate is set to 4-6L / min.

[0007] In the above-mentioned RPS steering gear housing die-casting process, the mold design includes a movable mold assembly, a fixed mold assembly, a left core pull, a right core pull, an upper slider, a lower slider one, a lower slider two, a cooling system, and an ejection system. The movable mold assembly and the fixed mold assembly constitute the RPS housing cavity.

[0008] In the above-mentioned RPS steering gear housing die-casting process, during the solidification stage, the solidification time is 7-9 seconds.

[0009] In the above-mentioned RPS steering gear housing die-casting process, during the slow filling stage, the punch speed is controlled at 0.2-0.3 m / s.

[0010] In the above-mentioned RPS steering gear housing die-casting process, during the rapid filling stage, the punch speed is controlled at 3-4 m / s.

[0011] Compared with the prior art, the present invention realizes the application of such RPS complex shell in the die-casting process by reasonably designing the mold and process. Compared with the traditional gravity casting, the molten metal completes a higher speed filling and high pressure solidification process under the push of the injection punch, thereby obtaining the ideal internal quality of the product; the method of the present invention is used to produce ADC12 aluminum alloy automobile steering system castings with unequal wall thickness and complex structure, which effectively prevents defects such as pores and shrinkage holes at hot spots caused by air entrainment during the high-speed filling process; a water cooling system is set at the parts where it is not suitable to set the gate and the hot spot, and the mold temperature is adjusted, which greatly improves the production efficiency while avoiding product defects. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the mold structure of the present invention.

[0013] In the figure, 1. movable mold assembly; 2. fixed mold assembly; 3. left core pulling; 4. right core pulling; 5. upper slider; 6. lower slider 1; 7. lower slider 2; 8. cooling system; 9. ejection system. DETAILED DESCRIPTION

[0014] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments. Example

[0015] like Figure 1 As shown, a RPS steering gear housing die-casting process includes the following steps: S1: Preliminary work preparation: including mold design and pouring system design. The mold design includes a movable mold component 1, a fixed mold component 2, a left core pull 3, a right core pull 4, an upper slider 5, a lower slider 1 6, a lower slider 2 7, a cooling system 8, and an ejection system 9. The movable mold component 1 and the fixed mold component 2 constitute the RPS shell cavity.

[0016] S2: Determination of die-casting water cooling process. The water cooling process adopts local spot cooling to control the mold temperature and thermal effects. The water cooling starts after the injection is completed and is maintained for 20-30 seconds. The cooling water pressure is 0.4-0.6Mpa, and the flow rate is set to 4-6L / min.

[0017] S3: Die casting production; Die casting production includes: S31, slow filling stage, the punch speed is controlled at 0.2-0.3m / s, pushing the aluminum liquid to flow smoothly to the gate; S32, fast filling stage, the punch speed is controlled at 3-4m / s, and the aluminum liquid is pushed by the punch to fill the RPS shell cavity at high speed. Through the design of reasonable slag bag and exhaust, the gas in the cavity is discharged to avoid gas entrapment and ensure good internal quality; S33, pressurization stage; after the aluminum liquid fills the cavity, the punch applies a pressure of 80-100MPa to compact the casting to ensure the density and high strength of the RPS shell; S34, curing stage, after curing for 7-9 seconds, the product is fully formed; S4: demoulding; separating the movable mold assembly 1 from the fixed mold assembly 2; driving the core pulling rod to separate from the product cavity through two core pulling mechanisms; driving the locking block and the lower slider to separate through the lower slider; driving the upper slider 5 and the lower slider to separate from the side wall of the steering gear through the upper slider 5 and the lower slider mechanism.

[0018] During the slow filling stage,.

[0019] The present invention realizes the application of such RPS complex shell in the die casting process by reasonably designing the mold and process. Compared with the traditional gravity casting, the molten metal completes a higher speed filling and high pressure solidification process under the push of the injection punch, thereby obtaining the ideal internal quality of the product; the method of the present invention is used to produce ADC12 aluminum alloy automobile steering system castings with different wall thicknesses and complex structures, effectively preventing defects such as pores and shrinkage holes at hot spots caused by air entrainment during the high-speed filling process; a water cooling system is set at the parts where gates are not suitable and at the hot spots to adjust the mold temperature, thereby greatly improving the production efficiency while avoiding product defects.

[0020] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A RPS steering gear housing die-casting process, comprising the following steps: S1: Preliminary work preparation: including mold design and pouring system design; S2: Determination of die casting water cooling process; S3: Die casting production; Die casting production includes: S31, slow filling stage, pushes the aluminum liquid to flow smoothly to the gate; S32, fast filling stage, aluminum liquid is pushed by the punch to fill the RPS shell cavity at high speed, and the gas in the cavity is discharged through the design of reasonable slag bag and exhaust to avoid gas entrapment and ensure good internal quality; S33, pressurization stage: after the aluminum liquid fills the cavity, the punch applies a pressure of 80-100MPa to compact the casting to ensure the density and high strength of the RPS shell; S34, curing stage, after a period of curing, the product is completely formed; S4: demoulding; separating the movable mold assembly from the fixed mold assembly; driving the core pulling rod to separate from the product cavity through two core pulling mechanisms; driving the locking block and the lower slider to separate through the lower slider; driving the upper slider and the lower slider to separate from the side wall of the steering gear through the upper slider and the lower slider mechanism.

2. The RPS steering gear housing die-casting process according to claim 1, characterized in that: The water cooling process uses local spot cooling to control the mold temperature and thermal effects. The water cooling starts after the injection is completed and is maintained for 20-30 seconds. The cooling water pressure is 0.4-0.6Mpa, and the flow rate is set to 4-6L / min.

3. The RPS steering gear housing die-casting process according to claim 1, characterized in that: The mold design includes a movable mold component, a fixed mold component, a left core pull, a right core pull, an upper slider, a lower slider 1, a lower slider 2, a cooling system, and an ejection system. The movable mold component and the fixed mold component form an RPS shell cavity.

4. The RPS steering gear housing die-casting process according to claim 1, characterized in that: During the curing stage, the curing time is 7-9 seconds.

5. The RPS steering gear housing die-casting process according to claim 1, characterized in that: During the slow filling stage, the punch speed is controlled at 0.2-0.3m / s.

6. The RPS steering gear housing die-casting process according to claim 1, characterized in that: During the rapid filling stage, the punch speed is controlled at 3-4 m / s.

Images