CN114509220A - Device and method for detecting leakage point of automobile fuel vapor system - Google Patents

Abstract

The invention provides a device and a method for detecting a leakage point of an automobile fuel steam system, wherein the detection device comprises a choke valve assembly, a pressure pump device and a pressure display device, the choke valve assembly comprises a first choke valve and a second choke valve, a first pipeline leading to a carbon tank electromagnetic valve is connected at a first interface of an automobile carbon tank through the first choke valve, a second pipeline leading to a fuel tank is connected at a second interface of the carbon tank through the second choke valve, a third interface of the carbon tank is connected with the pressure pump through a third pipeline, and the third pipeline is provided with the pressure display device. The detection device disclosed by the invention is simple in structure, is controlled by an electronic circuit, and is more convenient and accurate to detect by combining an electronic digital pressure gauge.

Description

Device and method for detecting leakage point of automobile fuel vapor system

technical field

The invention relates to the technical field of vehicle detection, in particular to a leak point detection device and method of an automobile fuel vapor system.

Background technique

With the more stringent China VI emission standards, some new methods have been added to engine emission control, including fuel evaporation system leak detection, which can determine whether there is a leak in the fuel evaporation system. However, this method also has defects, and it is impossible to determine where the specific location of the leak point is.

In the fuel evaporation system, including the evaporation leak diagnostic pump, the diagnostic pump to the carbon canister line, the carbon canister, the carbon canister to the front engine line, the carbon canister solenoid valve, the carbon canister to the fuel tank line, the fuel tank and the various connections mouth. The current repair method is to replace the possible related parts in the fuel evaporation system one by one. This method is very inefficient. The average repair time is about 2 hours per unit, and there is a waste of cost caused by wrong parts replacement. Therefore, being able to accurately determine the leak point is of great significance to the repair work, which can improve work efficiency and reduce the cost loss caused by misjudgment.

SUMMARY OF THE INVENTION

In view of the above-mentioned problems, the present invention aims to provide a device and method for detecting the leakage point of an automobile fuel vapor system. By connecting to the pipeline pressure test system before subdivided detection, the faulty pipeline system is found, and then the diagnostic equipment is used Finally, the leak point is determined, thereby effectively saving the time for leak point detection in the fuel vapor system. The purpose of this invention is to realize through the following technical solutions:

The present invention first provides a leak point detection device for an automobile fuel vapor system, which includes a choke valve assembly, a pressure pump device and a pressure display device, wherein the choke valve assembly includes a first choke valve and a second choke valve. The first interface of the carbon canister is connected to the first pipeline leading to the carbon canister solenoid valve through the first choke valve, and the second interface of the carbon canister is connected to the second pipeline leading to the fuel tank through the second choke valve, The third interface of the carbon canister is connected to the pressure pump through a third pipeline, and a pressure display device is provided on the third pipeline.

Further, the choke valve assembly further includes a third choke valve, and the third interface of the carbon canister is connected to the third pipeline through the third choke valve.

Further, the first choke valve, the second choke valve and the third choke valve have quick connection interfaces. The quick-connect interface can realize the quick plugging and unplugging of the choke valve and the pipeline, and improve the working efficiency.

Further, the detection device further includes an electronically controlled switch assembly and a power supply, the first, second and third air choke valves are all electrically controlled choke valves, and the three choke valves pass through the The first circuit, the second circuit and the third circuit connected in parallel are connected to the power supply, and the switch assembly includes a first circuit, a second circuit and a third circuit respectively disposed on the first circuit, the second circuit and the third circuit and correspondingly controlling the first choke valve and the second choke valve. The first electric control switch, the second electric control switch and the third electric control switch of the valve and the third choke valve.

Further, the first electronically controlled switch, the second electronically controlled switch and/or the third electronically controlled switch are normally closed switches, and normally closed switches are used, so that the tubes connected to the carbon canister can be All roads are passages, which can effectively avoid excessive pressure at a certain node in the fuel vapor system or excessive pressure in the diagnosis system caused by misoperation of the pressure pump, thereby ensuring the safety and reliability of the diagnosis process.

Further, the electronically controlled switch assembly further includes a fourth electronically controlled switch, the pressure pump adopts an electric pressure pump, and the electric pressure pump is connected to a power source through a fourth circuit, and the fourth circuit is provided with a power source for controlling the electric pressure pump the fourth electronically controlled switch.

Further, the electronically controlled switch assembly is integrated on the controller and controlled by the controller.

Further, the pressure display device includes an electronic digital pressure gauge, and the electronic digital pressure gauge displays the pressure of the corresponding corresponding system during the detection process, which can further help the maintenance personnel to understand the system status more intuitively and ensure the rationality and reliability of the maintenance results.

Further, the pressure pump adopts a pneumatic pump.

Further, the third pipeline has a diagnostic pump branch circuit and a pressure pump branch circuit, the diagnostic pump branch circuit is connected to the oil tank seal diagnostic pump, and the pressure pump branch circuit is connected to the pressure pump.

The present invention further provides a method for detecting the leak point of an automobile fuel vapor system, which is characterized in that resistances are respectively arranged on the connecting pipelines between the carbon canister and the fuel tank, the carbon canister and the carbon canister solenoid valve, and the carbon canister and the fuel tank sealing diagnostic pump. A pressure pump shunt and a pressure display device are set on the connection pipeline between the carbon canister and the fuel tank seal diagnostic pump. By sequentially turning on and off different choke valves, the pressure pump is used to inflate the fuel vapor system, and with the help of pressure The display device judges the sealing status of different pipelines.

Further, the method adopts the aforementioned detection device to complete the detection.

The detection device of the present invention has an exquisite structure and is convenient to use. The pipeline system where the leakage point is located in the fuel evaporation system can be quickly located through the cooperation between the pressure pump and the choke valve, and the precise position of the leakage point can be further determined through the sealed diagnostic pump. , It is easy for repair personnel to judge faults, improve work efficiency, and reduce cost losses caused by wrong judgments. High maintenance efficiency; at the same time, with the use of electronic circuit control, combined with electronic digital pressure gauges, the detection is more convenient and accurate.

Description of drawings

FIG. 1 shows a leak point detection device for a vehicle fuel vapor system according to a preferred embodiment of the present invention;

In the picture:

101-carbon canister; 103-engine intake manifold; 202-pressure pump;

102-fuel tank; 201-tank seal diagnostic pump; 203-pressure display device.

Detailed ways

The preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

The present invention provides a leak point detection device for an automobile fuel vapor system, which includes a choke valve assembly, a pressure pump device and a pressure display device, wherein the choke valve assembly includes a first choke valve V1 and a second choke valve V2, The first port M1 of the car carbon canister 101 is connected to the first pipeline P1 leading to the carbon canister solenoid valve V4 through the first choke valve V1, and the second port M2 of the carbon canister is connected to the first pipeline P1 leading to the carbon canister solenoid valve V4 through the second choke valve V2 The second pipeline P2 of the fuel tank 102 and the third interface M3 of the carbon canister 101 are respectively connected to the pressure pump 202 and the fuel tank seal diagnostic pump 201 through the pressure pump branch P32 and the diagnostic pump branch P31 of the third pipeline P3. A pressure display device 203 is provided on the third pipeline P3.

In the illustrated embodiment, the choke valve assembly further includes a third choke valve V3, and the third port M3 of the carbon canister 101 is connected to the third pipeline P3 through the third choke valve V3.

In a preferred embodiment, the first choke valve, the second choke valve and the third choke valve have quick connection ports. The quick-connect interface can realize the quick plugging and unplugging of the choke valve and the pipeline, and improve the working efficiency.

In the illustrated embodiment, the detection device further includes an electronically controlled switch assembly and a power source 300. The first choke valve V1, the second choke valve V2, and the third choke valve V3 are all electronically controlled choke valves. The two choke valves are respectively connected to the power supply 300 through the first circuit L1, the second circuit L2 and the third circuit L3 in parallel, and the switch assembly includes the first circuit L1, the second circuit L2 and the third circuit L3 respectively arranged on the first circuit L1, the second circuit L2 and the third circuit L3 And correspondingly control the first electric control switch K1, the second electric control switch K2 and the third electric control switch K3 of the first choke valve V1, the second choke valve V2 and the third choke valve V3. The control switch K1, the second electronic control switch K2 and the third electronic control switch K3 are normally closed switches.

In the illustrated embodiment, the electronically controlled switch assembly further includes a fourth electronically controlled switch K4, the pressure pump 202 adopts an electric pressure pump, and the electric pressure pump 202 is connected to the power source 300 through a fourth circuit L4. The circuit L4 is provided with a fourth electronic control switch K4 for controlling the electric pressure pump.

In a preferred embodiment, the electronically controlled switch assembly is integrated on the controller and controlled by the controller.

In a preferred embodiment, the pressure display device 203 is an electronic digital pressure gauge.

In a preferred embodiment, the pressure pump adopts a pneumatic pump.

In a preferred embodiment, the power source comes from the cigarette lighter of the vehicle itself.

The device of the present invention leads out the pressure pump branch gas pipe connected to the pressure pump 202 from the connection between the fuel tank diagnosis pump and the carbon canister. The pressure pump 202 pumps air into the pipeline through the branch circuit P32, and also measures the fuel tank through this pipeline. pressure of the sealing system.

The working principle of the present invention mainly uses the electromagnetic choke valve to control the opening and closing of each pipeline connection of the fuel vapor system, and then the pressure pump 202 is used to pump air into the corresponding pipeline, and then judged by the pressure state value of the pressure display device 203 Which part has a leak point, and then repair or replace it accordingly after judging. The following provides a method for leak point detection using this device:

Connect the electronically controlled choke valve to each pipeline according to the previous instructions, ensure that the pipeline is connected completely, and connect each electronically controlled switch to the cigarette lighter to obtain electricity:

Step 1: Turn on the first electric control switch K1, the second electric control switch K2 and the third electric control switch K3 for controlling the first choke valve V1, the second choke valve V2 and the third choke valve V3 , so that all three choke valves are in a non-ventilated state. Turn on the fourth electronic control switch K4 of the control pressure pump 202, and control the pressure pump 202 to inflate the pipeline. At this time, the pressure display device 203 is used to observe whether the pressure can rise to 20hpa. If it exceeds 20hpa, it means that there is no leakage from the fuel tank seal diagnostic pump 201 to the carbon canister 101 . If it is lower than 20hpa, it means that there is leakage from the fuel tank seal diagnostic pump 201 to the carbon canister 101 , and the fuel tank seal diagnostic pump 201 and the pipeline connected to the carbon canister 101 need to be repaired or replaced.

Step 2: Keep the fourth electronic control switch K4 closed to ensure that the control circuit L4 of the pressure pump 203 is turned on, and the pressure pump 203 continues to work. Close the third electronic control switch K3 that controls the third choke valve V3, make the third choke valve V3 in a ventilated state, and keep the first electric control switch K1 and the first choke valve V1 and the second choke valve V2. The two electronic control switches K2 are opened, and the two air choke valves are in a non-ventilated state. At this time, observe whether the pressure can rise to 20 hpa through the pressure display device 203 . If it exceeds 20hpa, it means that the carbon canister 101 has no leakage. If it is lower than 20hpa, it means that the carbon canister 101 is leaking, and the carbon canister needs to be repaired or replaced.

Step 3: Keep the fourth electronic control K4 closed, so that the pressure pump 202 continues to work to inflate the pipeline. Close the second electric control switch K2 and the third electric control switch K3 that control the second choke valve V2 and the third choke valve V3, make the two choke valves ventilated, and open the first choke valve V1. The first electronically controlled switch K1 makes the first choke valve V1 in a non-ventilated state. At this time, observe whether the pressure can rise to 20hpa through the pressure display device. If it exceeds 20hpa, it means that there is no leakage in the fuel tank 102 and its pipelines. If it is lower than 20hpa, it means that the fuel tank and its pipelines are leaking, and the fuel tank and its pipelines need to be repaired or replaced.

Step 4: Keep the fourth electronic control K4 closed, so that the pressure pump 202 continues to work to inflate the pipeline. Close the third electric control switch K3 and the first electric control switch K1 that control the third choke valve V3 and the first choke valve V1, make the two choke valves ventilated, and open the first electric control switch K1 that controls the second choke valve V2. The second electronically controlled switch K2 makes the second air choke valve V2 in a non-ventilated state. At this time, observe whether the pressure can rise to 20hpa through the pressure display device. If it exceeds 20hpa, it means that there is no leakage in the carbon canister solenoid valve V4 and its pipeline. If it is lower than 20hpa, it means that there is leakage in the carbon canister solenoid valve V4 and its pipeline, and the carbon canister solenoid valve and its pipeline need to be repaired or replaced.

After the pipelines with problems are determined through the above detection process, the oil tank seal diagnostic pump 201 is used to carry out more detailed diagnosis and detection of the corresponding pipelines, and finally the specific leakage points are determined. The method of this embodiment can quickly locate the pipelines where the leakage points exist. The system avoids the cost waste caused by replacing the possible related parts in the fuel evaporation system one by one, thereby effectively improving the work efficiency and reducing the cost loss caused by misjudgment.

Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should Various changes are made to it in detail without departing from the scope defined by the claims of the present invention; the dimensions described in the accompanying drawings and examples have nothing to do with the specific objects, and are not used to limit the protection scope of the present invention. The size can be selected and transformed according to actual needs.

Claims (12)

1. an automobile fuel vapor system leak point detection device, is characterized in that, comprises choke valve assembly, pressure pump device and pressure display device, and described choke valve assembly comprises first choke valve and second choke valve, The first interface of the carbon canister is connected to the first pipeline leading to the carbon canister solenoid valve through the first choke valve, and the second interface of the carbon canister is connected to the second pipeline leading to the fuel tank through the second choke valve , the third interface of the carbon canister is connected to the pressure pump through a third pipeline, and the third pipeline is provided with a pressure display device. 2 . The leakage point detection device of an automobile fuel vapor system according to claim 1 , wherein the choke valve assembly further comprises a third choke valve, and the third port of the carbon canister passes through the third choke valve. 3 . The valve is connected to the third line. 3 . The leakage point detection device of an automobile fuel vapor system according to claim 2 , wherein the first choke valve, the second choke valve and the third choke valve have quick connection interfaces. 4 . 4. The leakage point detection device of an automobile fuel vapor system according to claim 2, wherein the detection device further comprises an electronically controlled switch assembly and a power supply, the first choke valve and the second choke valve and the third choke valve are all electrically controlled choke valves, the three choke valves are respectively connected to the power supply through the first circuit, the second circuit and the third circuit in parallel, and the switch assembly comprises a , the second circuit and the third circuit and correspondingly control the first electric control switch, the second electric control switch and the third electric control switch of the first air choke valve, the second air choke valve and the third air choke valve. 5 . The leak point detection device of an automobile fuel vapor system according to claim 4 , wherein the first electric control switch, the second electric control switch and/or the third electric control switch are normally closed switches. 6 . . 6 . The leakage point detection device of an automobile fuel vapor system according to claim 4 , wherein the electronically controlled switch assembly further comprises a fourth electronically controlled switch, the pressure pump is an electric pressure pump, and the electric pressure pump is an electric pressure pump. 7 . The pressure pump is connected to the power source through a fourth circuit, and the fourth circuit is provided with a fourth electronically controlled switch for controlling the electric pressure pump. 7 . The leakage point detection device of an automobile fuel vapor system according to claim 4 , wherein the electronically controlled switch assembly is integrated on the controller and controlled by the controller. 8 . 8 . The leak point detection device of an automobile fuel vapor system according to claim 1 , wherein the pressure display device comprises an electronic digital pressure gauge. 9 . 9 . The leakage point detection device of an automobile fuel vapor system according to claim 1 , wherein the pressure pump is a pneumatic pump. 10 . 10 . The leak point detection device of an automobile fuel vapor system according to any one of claims 1 to 7 , wherein the third pipeline has a diagnostic pump branch circuit and a pressure pump branch circuit, and the diagnostic pump branch circuit has 10 . The circuit is connected to the tank seal diagnostic pump, and the pressure pump is branched to the pressure pump. 11. A method for detecting a leak point of an automobile fuel vapor system, characterized in that a choke valve is respectively provided on the connecting pipeline between the carbon canister and the fuel tank, the carbon canister and the carbon canister solenoid valve, and the carbon canister and the fuel tank seal diagnosis pump , and set up a pressure pump shunt and a pressure display device on the connection pipeline between the carbon canister and the fuel tank seal diagnostic pump. By sequentially turning on and off different choke valves, the pressure pump is used to inflate the fuel vapor system, and with the help of the pressure display device Determine the sealing status of different pipelines. 12 . The method for detecting a leak point of an automobile fuel vapor system according to claim 11 , wherein the detection is completed by using the detection device according to any one of claims 1 to 10 . 13 .

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