A fuel injector coating control valve

Abstract

This utility model discloses a fuel injector coating control valve, including a control valve sleeve and a sealing ball. The control valve sleeve has a sealing cone surface, a shoulder surface, a transition cone surface, and a chamfered oil outlet. The sealing cone surface is coated with a titanium nitride (TiN) coating. The sealing ball is a ceramic ball. The TiN coating covers the sealing cone surface, the transition cone surface, and the chamfered oil outlet, while the shoulder surface is not coated with TiN. This improves the wear resistance of the control valve sleeve sealing surface, reduces the risk of cavitation corrosion, and extends the service life of the control valve sleeve and fuel injector. The TiN coating reduces the coefficient of friction, decreasing frictional loss with high-speed fluid components. The high bonding strength between the TiN coating and the substrate extends the time before the valve sleeve coating detaches under the impact of high-speed fluid and the high-frequency seating of the valve ball. By using the TiN coating in combination with different substrates, it can meet the application requirements of different rail pressure platform products.

Description

Technical Field

[0001] This utility model belongs to the technical field of fuel supply system for internal combustion engines, and particularly relates to an injector coating control valve. Background Technology

[0002] In the operation of an internal combustion engine, the fuel injector plays a crucial role, precisely injecting high-pressure fuel into the combustion chamber to ensure the engine's normal operation. The opening and closing of the fuel injector is precisely controlled by a control valve. In the control valve's construction, the control valve sleeve (also called the valve seat) and the sealing ball work together to form a key sealing structure. This sealing structure effectively prevents fuel leakage when the fuel injector is closed, thus ensuring good sealing performance, which is essential for the stable operation and fuel economy of the internal combustion engine.

[0003] However, in practical applications, control valve sleeves (seats) face severe challenges from their operating environment. On one hand, when the injector is working, fuel flows at high speed, impacting the control valve sleeve (seat). Simultaneously, the control valve needs to frequently open and close. This high-speed fluid impact and high-frequency operation easily lead to wear on the control valve sleeve (seat). As wear intensifies, the sealing effect between the control valve sleeve (seat) and the sealing ball gradually decreases, significantly shortening the overall lifespan of the injector. Therefore, ensuring that the sealing surface of the control valve sleeve (seat) maintains a stable sealing effect over a long period has become a critical issue that urgently needs to be addressed in the industry.

[0004] On the other hand, the instability of fuel quality also causes additional damage to the control valve sleeve (seat). In actual use, some particulate matter inevitably mixes into the fuel, and sometimes there is excessive moisture. When the control valve sleeve (seat) operates for a long time in this fuel environment containing impurities and excessive moisture, these particles act like sandpaper, constantly rubbing against the sealing surface of the valve sleeve, forming scratches; while moisture, under the influence of high-speed fluid and temperature changes, triggers cavitation. Over time, scratches and cavitation accumulate and expand, accelerating the damage to the injector's sealing performance and severely affecting the performance and reliability of the internal combustion engine. Utility Model Content

[0005] To address the problems existing in the prior art, this utility model provides an injector coating control valve.

[0006] This invention is implemented as follows: an injector coating control valve includes a control valve sleeve and a sealing ball. The control valve sleeve has a sealing cone surface, a shoulder surface, a transition cone surface, and a chamfered oil outlet. The invention is characterized in that: the sealing cone surface is coated with a titanium nitride (TiN) coating; the sealing ball is a ceramic ball; the TiN coating covers the sealing cone surface, the transition cone surface, and the chamfered oil outlet, and the shoulder surface has no TiN coating.

[0007] More preferably, the base material of the control valve sleeve is selected from any of the following: W6Mo5Cr4V2 high carbon alloy tool steel; GCr15 high carbon bearing steel; 9Cr18Mo high carbon chromium stainless steel; Cr8Mo2SiV high carbon medium chromium cold work die steel.

[0008] More preferably, the cone angle of the sealing cone surface is 120° or 125°.

[0009] More preferably, the hardness of the TiN coating is between 1800 HV and 2200 HV.

[0010] More preferably, the thickness of the TiN coating is 2 μm to 4 μm.

[0011] More preferably, the heat resistance temperature of the TiN coating is ≥580℃, and the coating treatment temperature is <480℃.

[0012] More preferably, the ceramic ball is a silicon nitride ceramic ball.

[0013] More preferably, the TiN coating extends to the upper end face of the control valve sleeve.

[0014] More preferably, the substrate material of the scapular surface is directly exposed without any coating covering.

[0015] More preferably, the control valve is applied to a conical ball valve type fuel injector, wherein the sealing ball cooperates with the sealing cone to control the flow of fuel.

[0016] The advantages and technical effects of this utility model are as follows: Compared with the prior art, the coating control valve of this application has the following beneficial effects:

[0017] Improved wear resistance and cavitation resistance: Titanium nitride (TiN) coating has high hardness. When applied to key parts such as the sealing cone surface of the control valve sleeve (valve seat), it can effectively resist the wear of particulate matter in fuel and cavitation caused by high-speed fluid impact, significantly extending the service life of the control valve sleeve (valve seat) and injector.

[0018] Reduced friction loss: TiN coating can reduce the coefficient of friction between the control valve sleeve (valve seat) and high-speed fluid components (such as sealing ball), reduce energy loss caused by friction, and improve the working efficiency of the injector.

[0019] Enhanced coating bonding strength: The TiN coating has high bonding strength with the substrate material, which can prolong the coating peeling time in harsh working environments such as high-speed fluid and high-frequency impact of valve ball sitting, ensuring the long-term stable sealing performance of the control valve sleeve (valve seat).

[0020] Meeting diverse product needs: By combining TiN coating with different substrates (such as high-carbon alloy tool steel, high-carbon bearing steel, high-carbon chromium stainless steel, high-carbon medium-chromium cold work die steel, etc.), it can meet the usage requirements of different rail pressure platform products, and can also be extended to the field of low-carbon fuel injector control valves, with broad application prospects.

[0021] Achieving low-cost mass production: Under the premise of ensuring product reliability, TiN coated control valve sleeves can be mass-produced, and the coating cost is low, which helps to reduce the overall manufacturing cost of injectors and improve the market competitiveness of products. Attached Figure Description

[0022] Figure 1 An injector that is an embodiment of the control valve of this application

[0023] Figure 2 This application provides a control valve sleeve.

[0024] Figure 3 This is a partial enlarged view of the sealing cone surface of the control valve in this application. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this utility model clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this utility model.

[0026] The coating control valve of this application is preferably applied to situations where the control valve is a conical ball valve.

[0027] like Figures 1 to 3 The diagram shows the structure of an injector implementing the coating control valve of this application. The shoulder surface 1a of the control valve sleeve 1 contacts and seals with the inner end face 2a of the housing 2. The force it receives comes from the tightening force of the control valve screw 4 acting on the large end face 1b of the control valve sleeve, which is transmitted to the shoulder surface 1a of the control valve sleeve, thus fixing the control valve sleeve 1 to the housing 2 and ensuring the seal at the inner end face 2a of the housing 2.

[0028] The upper end 1c of the control valve sleeve 1 forms a ball valve sealing valve with the sealing ball 3. When the sealing ball 3 contacts and seals the sealing cone surface 1d of the control valve sleeve 1, the injector does not inject oil; when the sealing ball 3 disengages from the sealing cone surface 1d of the control valve sleeve 1, the injector starts to inject oil.

[0029] like Figure 2 The diagram shows the structure of the injector coating control valve sleeve of this application. A volumetric cavity is formed at the center of the upper end of the control valve sleeve 1. A sealing cone surface 1d is provided within the volumetric cavity, and an oil outlet chamfer 1e is provided at the lower end of the sealing cone surface 1d. A transition cone surface 1f is provided at the upper part of the volumetric cavity, which connects with the sealing cone surface 1d and the upper end surface 1b. A shoulder surface 1a is provided at the lower part of the large end of the control valve sleeve 1, which contacts and seals with the housing 2.

[0030] In this application, the sealing cone surface 1d is coated with a titanium nitride (TiN) coating, and the angle β of the sealing cone surface 1d is 120° or 125°. Selecting an appropriate cone angle can achieve the best sealing effect and fuel injection control according to the specific injector operating requirements and fuel injection characteristics.

[0031] The sealing ball 3 of the coated control valve sleeve 1 is a silicon nitride ceramic ball. Silicon nitride ceramic balls have advantages such as high hardness, high wear resistance, high temperature resistance and good chemical stability. When used in conjunction with the sealing cone surface 1d coated with TiN, they can effectively reduce the wear of the sealing surface, improve the stability and reliability of the seal, and thus better ensure the reliability of the product.

[0032] The transition cone surface 1f, the upper end face 1b, and the large outer circle 1h are all permitted to have a titanium nitride (TiN) coating. The chamfer 1e at the oil outlet is also permitted to be coated with a titanium nitride (TiN) coating. Applying a TiN coating to these areas can further enhance the wear resistance and cavitation resistance of the control valve sleeve in these critical regions, improving the overall performance of the control valve sleeve.

[0033] In this application, the shoulder surface 1a that contacts the housing 2 is not allowed to have a titanium nitride (TiN) coating. This is because the shoulder surface 1a mainly bears the sealing function with the housing 2, and its sealing effect mainly depends on the tight fit with the inner end face 2a of the housing 2 and the tightening force of the control valve screw 4. Applying a coating may affect its sealing performance and assembly accuracy.

[0034] The base material of the control valve sleeve 1 (valve seat) implemented in this application can be high-carbon alloy tool steel such as W6Mo5Cr4V2; high-carbon bearing steel such as GCr15; high-carbon chromium stainless steel such as 9Cr18Mo; or high-carbon medium-chromium cold work die steel such as Cr8Mo2SiV. The preferred material can be selected based on different product application scenarios and cost considerations. For example, in applications requiring high hardness and wear resistance, W6Mo5Cr4V2 high-carbon alloy tool steel can be selected; in applications where cost-effectiveness is important and wear resistance is a certain requirement, GCr15 high-carbon bearing steel can be selected.

[0035] The titanium nitride (TiN) coating used in the control valve sleeve 1 (valve seat) of this application has a hardness of 1800-2200HV. The higher hardness can enhance the wear resistance of the surface of the control valve sleeve 1, effectively resist the wear of particulate matter in fuel, and reduce the generation of scratches on the sealing surface.

[0036] The titanium nitride (TiN) coating used in the control valve sleeve 1 (valve seat) of this application has a thickness of 2μm-4μm. The appropriate thickness can ensure that the coating has good adhesion and wear resistance, and will not affect the dimensional accuracy and assembly performance of the control valve sleeve 1 due to excessive thickness.

[0037] The titanium nitride (TiN) coating used in the control valve sleeve 1 (valve seat) of this application has a heat resistance temperature of ≥580℃, which can withstand the high-temperature environment generated during the operation of the fuel injector and ensure that the coating can maintain stable performance at high temperatures. At the same time, the coating treatment temperature is <480℃ to avoid adverse effects on the base material of the control valve sleeve 1 during the coating treatment process and to ensure that the performance of the base material is not damaged.

[0038] The titanium nitride (TiN) coating used in the control valve sleeve 1 (valve seat) of this application is golden yellow, which helps to visually inspect and judge the coating quality during the production process.

[0039] One embodiment of the control valve seat in this application is the same as the control valve sleeve described above, and also possesses the aforementioned features and advantages. It can meet the performance requirements of the injector for the control valve seat and improve the overall performance and reliability of the injector.

[0040] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An oil injector coating control valve, comprising a control valve sleeve (1) and a sealing ball (3), the control valve sleeve (1) is provided with a sealing cone surface (1d), a shoulder surface (1a), a transition cone surface (1f) and an oil outlet hole chamfer (1e), characterized in that: The sealing cone surface (1d) is coated with a titanium nitride (TiN) coating; the sealing ball (3) is a ceramic ball; the TiN coating covers the sealing cone surface (1d), the transition cone surface (1f) and the oil outlet chamfer (1e), and the shoulder surface (1a) has no TiN coating.

2. The control valve according to claim 1, characterized in that: The base material of the control valve sleeve (1) is selected from any of the following: W6Mo5Cr4V2 high carbon alloy tool steel; GCr15 high carbon bearing steel; 9Cr18Mo high carbon chromium stainless steel; Cr8Mo2SiV high carbon medium chromium cold work die steel.

3. The control valve according to claim 1, characterized in that: The cone angle of the sealing cone surface (1d) is 120° or 125°.

4. The control valve according to claim 1, characterized in that: The hardness of the TiN coating is 1800 HV to 2200 HV.

5. The control valve according to claim 1, characterized in that: The thickness of the TiN coating is 2 μm to 4 μm.

6. The control valve according to claim 1, characterized in that: The TiN coating has a heat resistance temperature ≥580℃ and a coating treatment temperature <480℃.

7. The control valve according to claim 1, characterized in that: The ceramic spheres are silicon nitride ceramic spheres.

8. The control valve according to claim 1, characterized in that: The TiN coating also extends to the upper end face (1b) of the control valve sleeve (1).

9. The control valve according to claim 1, characterized in that: The substrate material of the scapular surface (1a) is directly exposed without any coating.

10. The control valve according to any one of claims 1-9, characterized in that: The control valve is applied to a conical ball valve type fuel injector, and the sealing ball (3) cooperates with the sealing cone (1d) to control the fuel flow.

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