Sealing ring of water pump shell of automobile engine

Abstract

The invention relates to the technical field of sealing rings, in particular to a sealing ring of an automobile engine water pump shell. An elastic sealing lip layer; a spacer ring layer; the elastic sealing lip layers are oppositely arranged to be of a U-shaped double-lip structure, each lip end is provided with a fillet, and the lip side is provided with a guide inclined face so as to assist assembly. The spacer ring layer is located on the outer side of the double-lip structure and used for controlling the lip compression amount after assembly and keeping the sealing gap consistent. The sealing structure is more reasonable in design and can adapt to high and low temperature changes and complex working conditions; the selected materials have excellent corrosion resistance, wear resistance and elastic recovery performance, so that the stability and durability of the product are improved; in the machining process, friction is small, noise is low, and the smoothness and comfort of operation of the whole machine can be improved; the whole structure is lighter, the light weight of the whole vehicle can be achieved, and the requirements of energy conservation and emission reduction are met; and the used raw materials have good recycling characteristics and accord with the development direction of green manufacturing.

Description

Technical Field

[0001] The invention relates to the technical field of sealing rings, in particular to a sealing ring for a water pump housing of an automobile engine. Background Art

[0002] With the development of new energy vehicles and intelligent driving, automobile engine cooling systems have put forward higher performance requirements for seals, including high temperature resistance, corrosion resistance, wear resistance, low friction loss, energy saving and environmental protection.

[0003] Although existing metal sealing rings (such as aluminum alloy or stainless steel) have high strength and rigidity, they are prone to microcracks caused by thermal fatigue under thermal cycling conditions of -40 to +150°C, and the processing and assembly costs are high. Rubber sealing rings (such as fluororubber and nitrile rubber) are prone to thermal aging, hardening and cracking in high-temperature environments. After aging for 168 hours in a 120°C environment, the hardness increases by more than 20%, the tensile strength decreases by more than 15%, and the tolerance to chemical media such as ethylene glycol coolants is poor. Although polymer materials such as polytetrafluoroethylene (PTFE) and polyvinyl chloride (PVC) have the advantages of self-lubrication and corrosion resistance, they have poor elastic recovery ability and insufficient wear resistance. The addition of fillers increases the processing difficulty and the cost significantly.

[0004] Therefore, existing seals generally have problems such as permanent deformation of the lip under thermal vibration cycles, large friction loss, short service life, high manufacturing cost, and large carbon emissions. Therefore, it is urgent to develop a sealing ring with a new structure and material collaborative design that combines high-temperature durability, excellent chemical stability, low friction performance and recyclable utilization characteristics to meet the comprehensive requirements of the new generation of automobile engines for reliability, economy and green environmental protection. To solve the above problems, we propose a sealing ring for automobile engine water pump housing. Summary of the Invention

[0005] In view of the deficiencies in the prior art, the present invention provides a sealing ring for a water pump housing of an automobile engine, which solves the problems raised in the background art.

[0006] The above technical objectives of the present invention are achieved through the following technical solutions:

[0007] A sealing ring for a water pump housing of an automobile engine, comprising:

[0008] annular body layer;

[0009] Elastic sealing lip layer;

[0010] Intercalary annulus;

[0011] The elastic sealing lip layers are relatively arranged to form a U-shaped double-lip structure, each lip end is provided with a rounded corner, and the lip side is provided with a guide slope to assist assembly;

[0012] The spacer ring layer is located outside the double-lip structure and is used to control the compression of the lip edge and maintain a consistent sealing gap after assembly.

[0013] Preferably, the annular body layer is composed of the following components in parts by weight:

[0014] Polyvinylidene fluoride 80–90 parts;

[0015] 5–15 parts antioxidants;

[0016] 3–8 parts lubricant;

[0017] 1–3 parts plasticizer.

[0018] Preferably, the elastic sealing lip layer is composed of the following components in parts by weight:

[0019] Polyvinylidene fluoride 70–85 parts;

[0020] 5–10 parts of polytetrafluoroethylene powder;

[0021] 5–10 parts of elastic modifier.

[0022] Preferably, the spacer ring layer is composed of the following components in parts by weight:

[0023] Polyvinylidene fluoride 80–90 parts;

[0024] 3–8 parts of graphite particles;

[0025] 1–3 parts binder.

[0026] Preferably, the sealing ring undergoes the following heat treatment process:

[0027] Bake at a constant temperature of 140℃±2℃ for 1.5 hours;

[0028] Cool naturally to room temperature at a rate not exceeding 1°C / min;

[0029] After heat treatment, the material has a crystallinity of ≥50% and a Shore hardness of 55–65.

[0030] Preferably, the outer surface of the sealing ring is sprayed with a polytetrafluoroethylene nano-coating after being pre-treated with low-pressure plasma. The coating has a thickness of 1-3 μm, an adhesion of ≥5 MPa, and a friction coefficient of ≤0.05.

[0031] Preferably, the PVDF raw material is recycled material with a recycling rate of not less than 50%, and complies with the ISO 14021 recycling mark standard.

[0032] The present invention also provides a method for preparing a sealing ring of an automobile engine water pump housing, comprising the following steps:

[0033] S1. Mix the materials according to the ratio of each layer and dry them at 60–80°C and 0.1 MPa vacuum for 1 hour.

[0034] S2. The dried raw material was fed into a twin-screw extruder at 50–70 rpm, heated in stages to 180°C, 190°C, and 200°C, with a back pressure of 2–5 MPa, and vacuum degassing was performed.

[0035] S3. The mixed material is injection molded at 200–220°C and an injection pressure of 80–120 MPa in a mold at a temperature of 40–60°C, and the mold is demolded after holding the pressure for 10 seconds to obtain a sealing ring blank;

[0036] S4. Place the blank in a hot air circulation oven and bake at a constant temperature of 140℃±2℃ for 1.5 hours, and then cool it naturally to room temperature at a rate of no more than 1℃ / min;

[0037] S5. The cooled seal ring is treated with low-pressure plasma and then sprayed with a 1–3 μm thick PTFE nanocoating, which is then cured at 80°C for 30 minutes.

[0038] S6. Finally, the sealing performance of the sealing ring is tested. Under 0.5MPa water pressure, the leakage rate is ≤1×10 -4 mL / min, tested according to GB / T 24587-2017.

[0039] In summary, the present invention mainly has the following beneficial effects:

[0040] 1. The present invention adopts polyvinylidene fluoride matrix material, combined with elastic modifier and PTFE micropowder to form a multi-layer structure that can still maintain excellent elasticity and sealing in the range of -40℃ to +150℃. PVDF itself has extremely high chemical stability and can resist corrosion from acids, alkalis and various coolant media, solving the defect that the material is prone to failure under both thermal and chemical dual harsh working conditions.

[0041] 2. The present invention proposes a new lip edge structure design with U-shaped double lips and a spacer ring layer: the guide bevel assists in assembly positioning, the rounded lip end reduces stress concentration, and the outer spacer ring layer accurately limits the lip edge compression after assembly to ensure consistent sealing gaps. This structure not only simplifies the assembly process and reduces manual errors, but also maintains stable sealing under hot and cold cycles and high-pressure impact conditions, significantly reducing maintenance frequency and costs.

[0042] 3. The present invention uses an integrated process of twin-screw extrusion and injection molding, followed by a constant temperature heat treatment of 140℃±2℃ for 1.5h and natural cooling of ≤1℃ / min, to significantly improve the material's crystallinity and dimensional stability. After low-pressure plasma pretreatment, a PTFE nano-coating (1–3μm) is sprayed on, with a friction coefficient of ≤0.05, further reducing operating resistance. The preparation process is efficient and consistent, and the utilization rate of PVDF recycled materials is not less than 50%, complying with the ISO 14021 standard, achieving green production and energy conservation and emission reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a schematic cross-sectional structural diagram of the sealing ring in Example 1 of the present invention.

[0044] Reference numerals: 100, annular body layer; 200, elastic sealing lip layer; 300, spacer ring layer. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the described embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] The following examples are intended to illustrate the present invention but are not intended to limit the scope of protection of the present invention. The conditions in the examples may be further adjusted according to specific conditions. Simple improvements to the method of the present invention within the scope of the present invention are also within the scope of protection claimed in the present invention.

[0047] Example 1

[0048] refer to Figure 1 , a sealing ring for a water pump housing of an automobile engine, comprising:

[0049] annular body layer 100;

[0050] Elastic sealing lip layer 200;

[0051] Spacer ring layer 300;

[0052] The elastic sealing lip layers 200 are relatively arranged to form a U-shaped double-lip structure, each lip end is provided with a rounded corner, and the lip side is provided with a guide slope to assist assembly;

[0053] The spacer ring layer 300 is located outside the double-lip structure and is used to control the compression of the lip edge and maintain a consistent sealing gap after assembly.

[0054] The annular body layer 100 is composed of the following components in parts by weight:

[0055] Polyvinylidene fluoride 80–90 parts;

[0056] 5–15 parts antioxidants;

[0057] 3–8 parts lubricant;

[0058] 1–3 parts plasticizer.

[0059] The elastic sealing lip layer 200 is composed of the following components in parts by weight:

[0060] Polyvinylidene fluoride 70–85 parts;

[0061] 5–10 parts of polytetrafluoroethylene powder;

[0062] 5–10 parts of elastic modifier.

[0063] The spacer ring layer 300 is composed of the following components in parts by weight:

[0064] Polyvinylidene fluoride 80–90 parts;

[0065] 3–8 parts of graphite particles;

[0066] 1–3 parts binder.

[0067] The sealing ring is subjected to the following heat treatment process:

[0068] Bake at a constant temperature of 140℃±2℃ for 1.5 hours;

[0069] Cool naturally to room temperature at a rate not exceeding 1°C / min;

[0070] After heat treatment, the material has a crystallinity of ≥50% and a Shore hardness of 55–65.

[0071] The outer surface of the sealing ring is pretreated by low-pressure plasma and then sprayed with a polytetrafluoroethylene nano-coating. The coating has a thickness of 1-3 μm, an adhesion of ≥5 MPa, and a friction coefficient of ≤0.05.

[0072] The PVDF raw material is recycled material with a recycling rate of not less than 50%, and complies with the ISO 14021 recycling mark standard.

[0073] The present invention also provides a method for preparing a sealing ring of an automobile engine water pump housing, comprising the following steps:

[0074] S1. Mix the materials according to the ratio of each layer and dry them at 60–80°C and 0.1 MPa vacuum for 1 hour.

[0075] S2. The dried raw material was fed into a twin-screw extruder at 50–70 rpm, heated in stages to 180°C, 190°C, and 200°C, with a back pressure of 2–5 MPa, and vacuum degassing was performed.

[0076] S3. The mixed material is injection molded at 200–220°C and an injection pressure of 80–120 MPa in a mold at a temperature of 40–60°C, and the mold is demolded after holding the pressure for 10 seconds to obtain a sealing ring blank;

[0077] S4. Place the blank in a hot air circulation oven and bake at a constant temperature of 140℃±2℃ for 1.5 hours, and then cool it naturally to room temperature at a rate of no more than 1℃ / min;

[0078] S5. The cooled seal ring is treated with low-pressure plasma and then sprayed with a 1–3 μm thick PTFE nanocoating, which is then cured at 80°C for 30 minutes.

[0079] S6. Finally, the sealing performance of the sealing ring is tested. Under 0.5MPa water pressure, the leakage rate is ≤1×10 -4 mL / min, tested according to GB / T 24587-2017.

[0080] Example 2

[0081] To further verify the comprehensive performance advantages of the PVDF composite sealing ring of the present invention over the existing technology in terms of lightweight, energy saving and emission reduction, low noise, efficient sealing and recycling, this example compares the performance of conventional fluororubber sealing rings, traditional metal O-rings, and the PVDF composite sealing ring of the present invention in terms of their own performance and overall performance:

[0082] 1. Sample information

[0083] Sample A: Fluororubber (FKM) seal, a conventional high-temperature rubber seal available on the market;

[0084] Sample B: PVDF composite sealing ring of the present invention (prepared in Example 1), PVDF+PTFE micropowder+elasticity modifier multilayer structure;

[0085] Sample C: Aluminum water pump housing + metal O-ring, traditional metal O-ring assembly;

[0086] Sample D: Aluminum water pump housing + PVDF composite sealing ring (prepared in Example 1), the aluminum housing is assembled with the sealing ring of the present invention (PVDF recycled material ≥50%).

[0087] 2. Test conditions

[0088] Temperature cycle: -40°C to +150°C, hold each temperature for 30 minutes, cycle 1000 times;

[0089] Working pressure: 0.5MPa water pressure;

[0090] Corrosive medium: 50% ethylene glycol-water mixed coolant;

[0091] Friction and wear (Group I & II): Linear speed 0.5 m / s, load 50 N, duration 100 h;

[0092] Complete machine simulation bench (Group II): Drive speed 3000 rpm, continuous operation for 24 hours.

[0093] 3. Test indicators and results

[0094] 3.1 Group I: Comparison of sealing ring performance, refer to Table 1

[0095]

[0096]

[0097] Table 13.2 Group II: Overall performance comparison, refer to Table 2

[0098]

[0099] Table 2

[0100] 4. Results Analysis

[0101] In Group I, the leakage rate of sample B is only 1 / 5 of that of sample A, and the number of cycles to failure exceeds 1,000, while sample A only has about 450 cycles;

[0102] In Group II, sample D still maintained ≤1.0×10 -4 mL / min leak rate.

[0103] The friction coefficient of PVDF composite sealing ring is significantly better than that of FKM and metal rings (0.05 vs. 0.12 / 0.18);

[0104] Group II pump efficiency is increased from 72% to 80%, improving cooling system energy efficiency; noise is reduced by 10dB, improving system stability and driving comfort.

[0105] The sealing ring of sample D weighs only 28g, which is 41.7% lighter than traditional metal rings. It can reduce the CO2 emissions of the entire vehicle by about 0.25g / km, responding to the requirements of green and low-carbon development.

[0106] PVDF composite materials have minimal mass loss in friction, wear and chemical corrosion tests, and their service life is significantly extended;

[0107] Sample D uses ≥50% PVDF recycled materials, complies with ISO 14021 standards, and achieves the goals of material recycling and environmental protection and energy conservation.

[0108] In summary, the comparative experiments in this embodiment fully demonstrate that the PVDF composite sealing ring of the present invention has significant advantages in terms of sealing, durability, low friction, low noise, lightweight and green recycling.

[0109] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that, unless otherwise defined, the technical or scientific terms used in the present invention shall have the usual meanings understood by persons having ordinary skills in the field to which the present invention belongs, and the words "include" or "comprise" and the like used in the present invention mean that the elements or objects preceding the word include the elements or objects listed after the word and their equivalents. Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention shall be defined by the appended claims and their equivalents.

Claims

1. A sealing ring for an automobile engine water pump housing, characterized in that: include: an annular body layer (100); Elastic sealing lip layer (200); a spacer ring layer (300); The elastic sealing lip layers (200) are relatively arranged to form a U-shaped double-lip structure, each lip end is provided with a rounded corner, and the lip side is provided with a guide slope to assist assembly; The spacer ring layer (300) is located outside the double-lip structure and is used to control the compression amount of the lip edge and maintain a consistent sealing gap after assembly.

2. The sealing ring of the automobile engine water pump housing according to claim 1, characterized in that: The annular body layer (100) is composed of the following components in parts by weight: Polyvinylidene fluoride 80–90 parts; 5–15 parts antioxidants; 3–8 parts lubricant; 1–3 parts plasticizer.

3. The sealing ring of the automobile engine water pump housing according to claim 1, characterized in that: The elastic sealing lip layer (200) is composed of the following components in parts by weight: Polyvinylidene fluoride 70–85 parts; 5–10 parts of polytetrafluoroethylene powder; 5–10 parts of elastic modifier.

4. The sealing ring of the automobile engine water pump housing according to claim 1, characterized in that: The spacer ring layer (300) is composed of the following components in parts by weight: Polyvinylidene fluoride 80–90 parts; 3–8 parts of graphite particles; 1–3 parts binder.

5. The sealing ring of the automobile engine water pump housing according to claim 1, characterized in that: The sealing ring is subjected to the following heat treatment process: Bake at a constant temperature of 140℃±2℃ for 1.5 hours; Cool naturally to room temperature at a rate not exceeding 1°C / min; After heat treatment, the material has a crystallinity of ≥50% and a Shore hardness of 55–65.

6. The sealing ring of the automobile engine water pump housing according to claim 1, characterized in that: The outer surface of the sealing ring is pretreated by low-pressure plasma and then sprayed with a polytetrafluoroethylene nano-coating. The coating has a thickness of 1-3 μm, an adhesion of ≥5 MPa, and a friction coefficient of ≤0.

05.

7. The sealing ring of the automobile engine water pump housing according to claim 1, characterized in that: The PVDF raw material is recycled material with a recycling rate of not less than 50%, and complies with the ISO 14021 recycling mark standard.

8. A method for preparing a sealing ring for a car engine water pump housing according to claims 1 to 7, characterized in that: The following steps are involved: S1. Mix the materials according to the ratio of each layer and dry them at 60–80°C and 0.1 MPa vacuum for 1 hour. S2. The dried raw material was fed into a twin-screw extruder at 50–70 rpm, heated in stages to 180°C, 190°C, and 200°C, with a back pressure of 2–5 MPa, and vacuum degassing was performed. S3. The mixed material is injection molded at 200–220°C and an injection pressure of 80–120 MPa in a mold at a temperature of 40–60°C, and the mold is demolded after holding the pressure for 10 seconds to obtain a sealing ring blank; S4. Place the blank in a hot air circulation oven and bake at a constant temperature of 140℃±2℃ for 1.5 hours, and then cool it naturally to room temperature at a rate of no more than 1℃ / min; S5. The cooled seal ring is treated with low-pressure plasma and then sprayed with a 1–3 μm thick PTFE nanocoating, which is then cured at 80°C for 30 minutes. S6. Finally, the sealing performance of the sealing ring is tested. Under 0.5MPa water pressure, the leakage rate is ≤1×10 -4 mL / min, tested according to GB / T 24587-2017.

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