Carbon canister assembly suitable for national 7 emission standard

Abstract

A carbon canister assembly suitable for the national 7 emission standard comprises a carbon canister and an isolating valve, the isolating valve is integrated at an atmosphere opening of the carbon canister and connected with the atmosphere opening through a connecting plug and a connecting pipe opening, a sealing rubber ring is arranged at the connecting position, an upper clamping jaw and a lower clamping jaw are arranged outside the connecting plug, and the upper clamping jaw and the lower clamping jaw are clamped to protrusions outside the connecting pipe opening. And a buckle is arranged on the isolating valve and is clamped with an assembling groove of the upper bracket of the carbon canister. According to the utility model, the isolating valve (FTIV) is integrated at the atmosphere port of the carbon canister, the oil tank assembly and the carbon canister are used as an integral high-pressure system for management, and the isolating valve seals gasoline steam in the oil tank in the oil tank and the carbon canister for circulation, so that the carbon canister can be completely prevented from generating outward emission in an evaporative emission test, the DBL is effectively controlled, and the service life of the carbon canister is prolonged. The national 7 emission standard is met.

Description

Technical Field

[0001] The utility model relates to the technical field of automobile carbon canister assemblies, in particular to a carbon canister assembly applicable to the National Seven emission standards. Background Art

[0002] With increasingly stringent environmental protection requirements and the emphasis on fuel economy, the charcoal canister assembly, as an important component of the fuel evaporation control system, plays a key role. In order to reduce the impact of automobile exhaust emissions on the environment, promote the sustainable development of the automobile industry, and protect the health of the public and the balance of the ecological environment, the National VI standard was promulgated. Now, the latest version of China's automobile emission standards is about to be ushered in - the National VII emission standard. This standard is expected to be fully implemented after 2028. It aims to further reduce the maximum allowable emissions of air pollutants, including fine particulate matter, hydrocarbons and carbon monoxide, on the basis of the National VI emission standard, in order to improve air quality and protect people's health. Compared with the National VI standard, the National VII standard will be more stringent and require automakers to adopt more advanced technologies to reduce pollutant emissions.

[0003] The above emission requirements are mainly reflected in tail gas emissions and evaporative emissions. The National VI emission test tests the evaporative emissions of the whole vehicle, including the wall penetration of fuel system parts such as the fuel tank / filler pipe and leakage at the joints, emissions from the engine injection system and charcoal canister atmospheric port emissions (DBL). The sum of emissions from the above sources must meet the specified present value, while the National VII adds a separate test for charcoal canister atmospheric port emissions (BETP) and separately stipulates emission limits, which undoubtedly puts forward newer and higher requirements for the fuel system.

[0004] The conventional practice in the prior art is to integrate honeycomb carbon at the atmospheric port of the charcoal canister, and utilize its adsorption characteristics to effectively adsorb fuel vapor, which has the characteristic of reducing emissions. However, the cost of honeycomb carbon is relatively high, and sometimes multiple honeycomb carbons need to be added to effectively control atmospheric port emissions (DBL) and reduce them to meet the limit requirements; the invention patent with application number 201680030245.6 provides a method for switching from a pressurized fuel system to a non-pressurized fuel system when an evaporative emission leak is detected. Its structure is to install an isolation valve on the pipeline between the fuel tank and the charcoal canister. Although it can solve the problem of vehicle emissions of hybrid vehicles that meet the National VI standard, it cannot meet the requirements of the National VII standard for the separate test of charcoal canister atmospheric port emissions (BETP). Summary of the invention

[0005] The purpose of the utility model is to provide a carbon canister assembly which complies with the National Seventh Emission Standard and can completely prevent the carbon canister from discharging gasoline vapor to the outside, so as to overcome the shortcomings of the above-mentioned prior art.

[0006] The technical solution adopted by the utility model is: a carbon canister assembly applicable to the National VII emission standard, comprising a carbon canister and an isolation valve, wherein the isolation valve is integrated at the atmospheric port of the carbon canister, and the isolation valve is also electrically connected to the engine electronic control unit.

[0007] A further technical solution is: a connecting pipe opening is provided at the atmospheric port of the carbon canister, a connecting plug is provided at one side of the isolation valve, and the connecting plug is inserted into the connecting pipe opening and fits therewith.

[0008] Furthermore, the connecting pipe mouth is provided with a circle of protrusions outside, and the connecting plug is provided with upper claws and lower claws outside. When the connecting plug is inserted into the connecting pipe mouth, the upper claws and the lower claws are clamped on the outside of the connecting pipe mouth and respectively engage with the protrusions.

[0009] Further: a sealing rubber ring is provided at the connection between the connecting pipe opening and the connecting plug.

[0010] Further: a bracket is arranged on the carbon canister, a mounting groove is arranged in the bracket, a buckle is arranged on one side of the corresponding isolation valve, and the buckle is inserted into the mounting groove and engaged with the bracket.

[0011] Further: a fixing bracket is arranged on the isolation valve, and the fixing bracket is fixed to the carbon canister by bolts.

[0012] Due to the adoption of the above technical solution, the carbon canister assembly of the utility model applicable to the National VII emission standard has the following beneficial effects:

[0013] 1. Since the utility model integrates an isolation valve (FTIV) at the atmospheric port of the charcoal canister, the fuel tank assembly plus the charcoal canister are managed as an integrated high-pressure system. The isolation valve seals the gasoline vapor in the fuel tank inside the fuel tank and the charcoal canister for circulation, which can completely prevent the charcoal canister from generating external emissions during the evaporative emission test, effectively control DBL, and meet the National VII emission standards;

[0014] 2. The utility model directly connects the isolation valve and the carbon canister, and the layout is very compact. It is much easier to arrange in plug-in hybrid vehicles with small space. It can not only save rubber tubes, but also avoid the risk of joint leakage caused by adding additional pipes, and at the same time reduce the procurement cost of pipes and joints;

[0015] 3. Since the utility model provides a connecting pipe port and a connecting plug for connecting the two on the carbon canister and the isolation valve respectively, and prevents the interface from falling off in the reverse direction through the engagement of the external claws and the protrusions, the connection is more secure;

[0016] 4. Since the utility model provides a buckle on the isolation valve, after the buckle is pushed into the assembly groove, the two sides of the buckle will naturally spring open and hang on the side wall of the assembly groove to form an effective connection. At the same time, it is also used to assist in fixing and supporting the weight of the isolation valve and limit the rotation and shaking of the isolation valve, which may affect the sealing performance;

[0017] 5. Since the utility model is provided with a sealing rubber ring, the air tightness of the connection between the carbon canister and the isolation valve is ensured.

[0018] The technical features of a carbon canister assembly applicable to the National VII emission standard of the utility model will be further described below in conjunction with the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the structure of a carbon canister assembly that is applicable to the National VII emission standard of the utility model;

[0020] Figure 2 This is a top view of a carbon canister assembly of the utility model that is applicable to the National VII emission standard;

[0021] Figure 3 for Figure 2 AA direction cross-sectional view;

[0022] Figure 4 for Figure 3 A magnified view of part B;

[0023] Figure 5 This is a schematic diagram of the isolation valve structure of the utility model;

[0024] Figure 6 It is a schematic diagram of the buckle connection structure of the utility model.

[0025] In the figure:

[0026] 1—charcoal canister, 11—connecting pipe opening, 12—protrusion, 13—bracket, 2—isolating valve, 21—connecting plug, 22—upper clamping claw, 23—lower clamping claw, 24—buckle, 3—sealing rubber ring. DETAILED DESCRIPTION

[0027] Embodiment 1: A carbon canister assembly applicable to the National VII emission standard comprises a carbon canister 1 and an isolation valve 2, wherein the isolation valve 2 is integrated at the atmospheric port of the carbon canister, and the two are directly connected, which not only saves rubber tubes, but also avoids the risk of joint leakage caused by adding additional pipelines, and at the same time reduces the procurement cost of pipelines and joints;

[0028] like Figure 1-Figure 6As shown, a connecting pipe port 11 is provided at the atmospheric port of the carbon canister, and a connecting plug 21 is provided at one side of the isolation valve 2. The connecting plug 21 is inserted into the connecting pipe port 11 and fits therewith. A sealing rubber ring 3 is provided at the connection between the connecting pipe port 11 and the connecting plug 21. A circle of protrusions 12 is provided outside the connecting pipe port 11, and an upper claw 22 and a lower claw 23 are provided outside the connecting plug 21. When the connecting plug 21 is inserted into the connecting pipe port 11, the upper claw 22 and the lower claw 23 are clamped outside the connecting pipe port 11 and respectively clamped with the protrusion 12 to prevent the interface from falling off in the reverse direction.

[0029] A bracket 13 is provided on the carbon canister 1, and a mounting groove is provided in the bracket 13. A buckle 24 is provided on one side of the corresponding isolation valve 2. The buckle 24 is inserted into the mounting groove and engaged with the bracket 13. After the buckle is pushed into the mounting groove, the two sides of the buckle are naturally opened and hooked on the side wall of the mounting groove to form an effective connection. At the same time, it is also used to assist in fixing and supporting the weight of the isolation valve and limit the rotation and shaking of the isolation valve, which may affect the sealing performance.

[0030] The isolation valve 2 is electrically connected to the engine electronic control unit and is a normally closed solenoid valve that opens under the following conditions:

[0031] ① Before refueling the vehicle, the isolation valve is energized under the control of the engine electronic control unit (ECU) and the isolation valve is opened;

[0032] ② When the internal pressure of the oil tank exceeds the safety pressure (generally 25~35kpa), the isolation valve opens mechanically and the oil tank pressure is released outward;

[0033] ③ When the negative pressure inside the oil tank exceeds the safe negative pressure (generally -15~-5kpa), the isolation valve opens through mechanical principles and the oil tank is replenished with negative pressure.

[0034] Working principle: The critical opening pressure of the fuel tank isolation valve (FTIV) is generally 28-35kpa. This pressure setting is generally higher than the pressure that may occur in the fuel system. It is a normally closed valve. The valve has two opening methods: one is to be pushed open when the pressure in the system reaches the critical pressure; the other is electromagnetic opening. The FTIV will open directly when the engine electronic control unit supplies power to it;

[0035] When conducting vehicle evaporative emission test or BETP test, as the ambient temperature rises, the fuel vapor pressure rises, and the internal pressure of the system gradually increases. However, because the FTIV is in the closed state, the gasoline vapor is sealed inside the system. In the BETP test, the fuel vapor will not leak into the environment. Therefore, the BETP can pass and meet the National VII emission standards.

[0036] The fuel system generally refers to the integration of the fuel tank, charcoal canister, refueling pipe and other connected pipelines. Since the fuel tank, charcoal canister and related pipelines need to withstand high pressure, it is not possible to simply strengthen the fuel tank like the National VI high-pressure fuel tank. Instead, the compressive strength of the pipelines and charcoal canisters must be considered. The general practice is to thicken the wall to ensure that the wall penetration effect is reduced, and to reduce product performance failure caused by wall displacement.

[0037] When performing the refueling emission test, the engine ECU gives a command to open the FTIV. At this time, the system is no different from a normal pressure system, ensuring normal refueling.

[0038] Embodiment 2: A carbon canister assembly applicable to the National VII emission standard, whose structure is basically the same as that of Embodiment 1, except that a fixing bracket is provided on the isolation valve, and the fixing bracket is fixed to the carbon canister by bolts.

[0039] The above embodiments are only preferred embodiments of the present invention. The structure of the present invention is not limited to the forms listed in the above embodiments. Any modifications, equivalent substitutions, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A carbon canister assembly applicable to the National VII emission standard, comprising a carbon canister (1), characterized in that: The carbon canister assembly further comprises an isolation valve (2), wherein the isolation valve (2) is integrated at the carbon canister atmospheric port, and the isolation valve (2) is also electrically connected to the engine electronic control unit.

2. The carbon canister assembly applicable to the National VII emission standard according to claim 1, characterized in that: A connecting pipe opening (11) is provided at the atmospheric port of the carbon canister, and a connecting plug (21) is provided on one side of the isolation valve (2). The connecting plug (21) is inserted into the connecting pipe opening (11) and fits closely therewith.

3. The carbon canister assembly applicable to the National VII emission standard according to claim 2, characterized in that: The connecting pipe opening (11) is provided with a circle of protrusions (12) on the outside, and the connecting plug (21) is provided with an upper clamping claw (22) and a lower clamping claw (23) on the outside. When the connecting plug (21) is inserted into the connecting pipe opening (11), the upper clamping claw (22) and the lower clamping claw (23) are clamped on the outside of the connecting pipe opening (11) and respectively engage with the protrusions (12).

4. The carbon canister assembly applicable to the National VII emission standard according to claim 2, characterized in that: A sealing rubber ring (3) is provided at the connection between the connecting pipe opening (11) and the connecting plug (21).

5. The carbon canister assembly applicable to the National VII emission standard according to claim 1, characterized in that: A bracket (13) is provided on the carbon canister (1), a mounting groove is provided in the bracket (13), a buckle (24) is provided on one side of the corresponding isolation valve (2), and the buckle (24) is inserted into the mounting groove and engaged with the bracket (13).

6. The carbon canister assembly applicable to the National VII emission standard according to claim 1, characterized in that: A fixing bracket is provided on the isolation valve (2), and the fixing bracket is fixed to the carbon canister (1) by means of bolts.

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