Charcoal canister inspection device

Abstract

To provide a charcoal canister inspection device which enables a short-time inspection for determining the presence or absence of any abnormality in a fuel evaporative gas discharge suppression device, even in a vehicle that is not equipped with a diagnostic device for diagnosing the fuel evaporative gas discharge suppression device, irrespective of the mounting location of a charcoal canister or the like.SOLUTION: A charcoal canister inspection device 10 enables inspection for the presence or absence of abnormality in a fuel evaporative gas discharge suppression device 20 by being connected to a fuel filler port 2 of a vehicle, the inspection device comprising: a pressure increasing / decreasing device 11 capable of performing at least one of increasing the internal pressure of a fuel tank 1 so as to exceed the opening pressure of a positive pressure valve 22a and decreasing the internal pressure so as to fall below the opening pressure of a negative pressure valve 22b; a pressure gauge 14 that is configured to measure the pressure inside the fuel tank 1; and a pressure display device that displays the pressure value measured by the pressure gauge 14.SELECTED DRAWING: Figure 1

Description

Technical Field

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[0001] The present invention relates to a charcoal canister inspection device for inspecting whether there is an abnormality in a fuel vapor emission suppression device mounted on a vehicle.

Background Art

[0002] Gasoline engine vehicles with high fuel volatility are equipped with a fuel vapor emission suppression device to suppress the emission of gasoline vapor evaporated in the fuel tank into the atmosphere. The fuel vapor emission suppression device is composed of a charcoal canister for adsorbing gasoline vapor, a check valve connected between the fuel tank and the charcoal canister, and other pipes. The fuel vapor emission suppression device is subject to regular inspections of motor vehicles in Japan. Therefore, it is necessary to inspect the clogging and damage of the charcoal canister, the function of the check valve, and the damage of the pipes every two years for private passenger cars and every year for private trucks and commercial vehicles.

[0003] Patent Document 1 discloses a vehicle equipped with a diagnostic device that can diagnose whether there is an abnormality in the fuel vapor emission suppression device. Such a diagnostic device is mounted on vehicles only in regions such as North America where installation is mandatory under regulations.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In vehicles without a diagnostic device capable of checking for abnormalities in the fuel evaporative emission control system, it was necessary to disconnect the hoses connected to the charcoal canister and check valve, blow air into the charcoal canister to check for blockages, and blow air into the check valve to check for proper operation during each statutory periodic inspection. However, in vehicles where the charcoal canister and check valve are located near the fuel tank, accessing these inspection points requires removing the rear seat cushion and service hole cover. As a result, these inspection procedures were time-consuming and took about 10 minutes. Furthermore, in vehicle models with different charcoal canister locations, the parts that need to be removed to access the inspection points differ, creating the problem of different inspection procedures depending on the location of the charcoal canister and other components.

[0006] Therefore, the present invention aims to provide a charcoal canister inspection device that can quickly check for any abnormalities in a fuel evaporative emission suppression device, regardless of the mounting position of the charcoal canister, etc., in a vehicle that is not equipped with a diagnostic device for diagnosing the fuel evaporative emission suppression device. [Means for solving the problem]

[0007] The charcoal canister inspection device according to the present invention is From outside the vehicle At the vehicle's fuel filler The connection part A charcoal canister inspection device that, when connected, can check for abnormalities in the fuel evaporative gas emission suppression device, and which pressurizes the air pressure inside the fuel tank to be higher than the opening pressure of the positive pressure valve and depressurizes it to be lower than the opening pressure of the negative pressure valve. both A pressure and depressurization device capable of doing so, A valve connected to the aforementioned pressure-reducing device and the connection part, which can switch between a state in which the pressure-reducing device pressurizes the air pressure inside the fuel tank and a state in which the pressure-reducing device depressurizes the air pressure inside the fuel tank, and a catch tank provided between the connection part and the valve, which can store fuel, The system is characterized by comprising a pressure gauge capable of measuring the atmospheric pressure inside the fuel tank, and a pressure indicator that displays the atmospheric pressure measured by the pressure gauge. [Effects of the Invention]

[0008] The present invention provides a charcoal canister inspection device that can quickly check for abnormalities in a fuel evaporative emission suppression device, regardless of the mounting position of the charcoal canister, etc., in vehicles that are not equipped with a diagnostic device for diagnosing the fuel evaporative emission suppression device. [Brief explanation of the drawing]

[0009] [Figure 1] This figure shows the configuration of a charcoal canister inspection device according to an embodiment of the present disclosure. [Figure 2] This diagram shows the airflow when the pressure inside the fuel tank is pressurized to a level higher than the opening pressure of the positive pressure valve during a pressure test. [Figure 3] This diagram shows the airflow when the air pressure inside the fuel tank is reduced to a level lower than the opening pressure of the negative pressure valve during a depressurization test. [Modes for carrying out the invention]

[0010] The charcoal canister inspection device 10 of this embodiment will be described below with reference to Figures 1 to 3. Figure 1 is a diagram showing the configuration of the charcoal canister inspection device 10. The charcoal canister inspection device 10 can inspect whether there is any abnormality in the fuel evaporative gas emission suppression device 20 by performing a pressurization test in which the air pressure inside the fuel tank 1 is increased to a level higher than the opening pressure of the positive pressure valve 22a, and a depressurization test in which the air pressure inside the fuel tank 1 is reduced to a level lower than the opening pressure of the negative pressure valve 22b. Figure 2 is a diagram showing the airflow in the fuel evaporative gas emission suppression device 20 when the air pressure inside the fuel tank 1 is increased to a level higher than the opening pressure of the positive pressure valve 22a in the pressurization test. Figure 3 is a diagram showing the airflow in the fuel evaporative gas emission suppression device 20 when the air pressure inside the fuel tank 1 is reduced to a level lower than the opening pressure of the negative pressure valve 22b in the depressurization test.

[0011] As shown in Figure 1, the charcoal canister inspection device 10 includes a pressure / depressurization device 11, two one-way valves 12a and 12b, a four-way valve 13, a pressure gauge 14, a catch tank 15, and a fuel inlet connection 16. The four-way valve 13 has four ports 13a, 13b, 13c, and 13d.

[0012] By operating the pressure regulator 11, it is possible to generate a pressure higher than the opening pressure of the positive pressure valve 22a at the positive pressure port 11a and a pressure lower than the opening pressure of the negative pressure valve 22b at the negative pressure port 11b. The positive pressure port 11a of the pressure regulator 11 is connected to the port 13a of the four-way valve 13 via a one-way valve 12a. Since the one-way valve 12a is a check valve, air can flow from the positive pressure port 11a of the pressure regulator 11 to the port 13a of the four-way valve 13, but air cannot flow from the port 13a of the four-way valve 13 to the positive pressure port 11a of the pressure regulator 11. The negative pressure port 11b of the pressure regulator 11 is connected to the port 13b of the four-way valve 13 via a one-way valve 12b. Since the one-way valve 12b is a check valve, air can flow from the port 13b of the four-way valve 13 towards the negative pressure port 11b of the pressure / vacuum device 11, but air cannot flow from the negative pressure port 11b of the pressure / vacuum device 11 towards the port 13b of the four-way valve 13.

[0013] Port 13c of the 4-way valve 13 is open to the atmosphere. Port 13d of the 4-way valve 13 is connected to the fuel filler port connector 16 via the catch tank 15. As shown in Figures 2-3, the fuel filler port connector 16 can be connected to the vehicle's fuel filler port 2 with the fuel filler cap 3 removed. When the fuel filler port connector 16 is connected to the vehicle's fuel filler port 2 in this way, a connection is established from port 13d of the 4-way valve 13 to the vehicle's fuel tank 1. With the fuel filler port connector 16 connected to the vehicle's fuel filler port 2, the vehicle's fuel filler cap 3 can be attached to the back of the fuel filler port connector 16. Since the fuel filler cap 3 has a built-in relief valve, when the fuel filler connection part 16 is connected to the vehicle's fuel filler 2 and the fuel filler cap 3 is attached to the back of the fuel filler connection part 16, even if the air pressure inside the fuel tank 1 is increased or decreased by a pressurization test or depressurization test, the air pressure inside the fuel tank 1 will not become excessively high or low. Also, as shown in Figure 1, the ports of the 4-way valve 13 13d Because a catch tank 15 is provided between the fuel tank 1 and the fuel filler port connection 16, even if fuel flows back from the fuel tank 1 when the pressure inside the fuel tank 1 is reduced by a depressurization test when the fuel tank 1 is full, it can be prevented from flowing back towards the 4-way valve 13 side from the catch tank 15.

[0014] As shown in Figure 1, a pressure gauge 14 is provided between the port 13d of the 4-way valve 13 and the catch tank 15. As shown in Figures 2-3, the pressure gauge 14 can measure the atmospheric pressure inside the vehicle's fuel tank 1 when the fuel filler port connection 16 is connected to the vehicle's fuel filler port 2 and the fuel filler cap 3 is attached to the back of the fuel filler port connection 16. The pressure gauge 14 is equipped with a display unit that shows the measured atmospheric pressure. In other words, the pressure gauge 14 combines the function of a pressure gauge that measures the atmospheric pressure inside the fuel tank 1 with the function of a pressure display unit that shows the measured atmospheric pressure.

[0015] The 4-way valve 13 can switch the position of the valve body 13e between two positions: the position shown by the solid line in Figure 1 and the position shown by the dashed line in Figure 1. When the valve body 13e of the 4-way valve 13 is in the position shown by the solid line in Figure 1, ports 13a and 13d are in communication, and ports 13b and 13c are in communication. When the valve body 13e of the 4-way valve 13 is in the position shown by the dashed line in Figure 1, ports 13a and 13c are in communication, and ports 13b and 13d are in communication.

[0016] As shown in Figures 2-3, the fuel evaporative gas emission suppression device 20 includes a charcoal canister 21, a check valve 22, a solenoid valve 23, and an atmospheric filter 24. The charcoal canister 21 is connected to the fuel tank 1 via the check valve 22. The charcoal canister 21 is also connected to the engine's intake system via the solenoid valve 23. Furthermore, the charcoal canister 21 communicates with the atmosphere via the atmospheric filter 24. The check valve 22 includes a positive pressure valve 22a and a negative pressure valve 22b. The positive pressure valve 22a opens as shown in Figure 2 when the air pressure inside the fuel tank 1 becomes a positive pressure higher than a predetermined opening pressure. The negative pressure valve 22b opens as shown in Figure 3 when the air pressure inside the fuel tank 1 becomes a negative pressure lower than a predetermined opening pressure.

[0017] The charcoal canister inspection device 10 can be used to inspect the vehicle's fuel vapor emission suppression device 20 for any abnormalities by performing a pressurization test and a depressurization test with the solenoid valve 23 closed, connecting the fuel filler port connector 16 to the vehicle's fuel filler port 2 as shown in Figures 2-3, and attaching the fuel filler cap 3 to the back of the fuel filler port connector 16. In these pressurization and depressurization tests, the pressurization / depressurization device 11 functions as a pressurization / depressurization device that pressurizes the air pressure inside the fuel tank 1 to be higher than the opening pressure of the positive pressure valve 22a during the pressurization test, and depressurizes the air pressure inside the fuel tank 1 to be lower than the opening pressure of the negative pressure valve 22b during the depressurization test.

[0018] When conducting the pressure test, with the valve body 13e of the four-way valve 13 positioned as shown by the solid line in Fig. 1, operate the pressure regulator 11 to generate a positive pressure higher than the opening pressure of the positive pressure valve 22a at the positive pressure port 11a. Then, since the port 13a and the port 13d of the four-way valve 13 are in communication, air flows from the positive pressure port 11a of the pressure regulator 11 through the one-way valve 12a to the port 13a of the four-way valve 13, flows through the four-way valve 13 from the port 13a to the port 13d, and then flows into the fuel tank 1 from the port 13d of the four-way valve 13 via the catch tank 15 and the fuel filler connection part 16. And, by thus causing air to flow into the fuel tank 1 from the positive pressure port 11a of the pressure regulator 11, the air pressure in the fuel tank 1 is pressurized to be higher than the opening pressure of the positive pressure valve 22a. Even in a state where the air pressure in the fuel tank 1 is pressurized to be higher than the opening pressure of the positive pressure valve 22a like this, the one-way valve 12a can hold the positive pressure in the fuel tank 1 so that it does not escape to the pressure regulator 11 side.

[0019] When the pressure regulator 11 is thus operated to pressurize the air pressure in the fuel tank 1 to be higher than the opening pressure of the positive pressure valve 22a, the positive pressure valve 22a of the check valve 22 opens. Therefore, as shown by the arrow in Fig. 2, the air in the fuel tank 1 is discharged from the charcoal canister 21 and the check valve 22 to the atmosphere through the charcoal canister 21 and the air filter २४. Therefore, the air pressure in the fuel tank 1 drops from a pressure higher than the opening pressure of the positive pressure valve 22a toward the opening pressure of the positive pressure valve 22a. In the pressure test, after operating the pressure regulator 11 to make the air pressure in the fuel tank 1 higher than the opening pressure of the positive pressure valve 22a, if the pressure value displayed on the pressure gauge 14 drops below a predetermined value within a predetermined time range, it can be determined that there is no blockage in the charcoal canister 21, the air filter 24, or the piping, and the positive pressure valve 22a of the check valve 22 is also operating normally. And when the pressure display of the pressure gauge 14 does not drop below a predetermined value within a predetermined time range, it can be determined that there is a blockage in the charcoal canister 21, the air filter 24, or the piping, or that a failure has occurred in the positive pressure valve 22a of the check valve 22.

[0020] When conducting a decompression test, with the valve body 13e of the four-way valve 13 in the position shown by the dashed line in Fig. 1, the pressure regulator 11 is operated to generate a pressure lower than the opening pressure of the negative pressure valve 22b at the negative pressure port 11b. Then, since the port 13b and the port 13d of the four-way valve 13 are in communication, the air in the fuel tank 1 flows to the port 13d of the four-way valve 13 via the fuel filler connection part 16 and the catch tank 15, flows through the four-way valve 13 from the port 13d to the port 13b, and flows out from the port 13b of the four-way valve 13 to the negative pressure port 11b of the pressure regulator 11 via the one-way valve 12b. And, as air thus flows out from the fuel tank 1 to the negative pressure port 11b of the pressure regulator 11, the air pressure in the fuel tank 1 is decompressed so as to be lower than the opening pressure of the negative pressure valve 22b. Even in a state where the air pressure in the fuel tank 1 is decompressed so as to be lower than the opening pressure of the negative pressure valve 22b, the one-way valve 12b can hold the negative pressure in the fuel tank 1 in order to prevent air from flowing in from the pressure regulator 11 side.

[0021] When the pressure regulator 11 is thus operated to decompress the air pressure in the fuel tank 1 so as to be lower than the opening pressure of the negative pressure valve 22b, the negative pressure valve 22b of the check valve 22 opens, and as shown by the arrow in Fig. 3, air flows into the fuel tank 1 from the air filter 24 via the charcoal canister 21 and the check valve 22. Therefore, the air pressure in the fuel tank 1 rises from a pressure lower than the opening pressure of the negative pressure valve 22b toward the opening pressure of the negative pressure valve 22b. In the decompression test, after the pressure regulator 11 is operated to make the air pressure in the fuel tank 1 lower than the opening pressure of the negative pressure valve 22b, if the pressure value displayed on the pressure gauge 14 rises to a predetermined value or more within a predetermined time range, it can be determined that there is no blockage in the charcoal canister 21, the air filter 24, or the piping, and the negative pressure valve 22b of the check valve 22 is also operating normally. And when the pressure display on the pressure gauge 14 does not rise to a predetermined value or more within a predetermined time range, it can be determined that there is a blockage in the charcoal canister 21, the air filter 24, or the piping, or that a failure has occurred in the negative pressure valve 22b of the check valve 22.

[0022] The charcoal canister inspection device 10 can be used in vehicles that do not have a diagnostic device for diagnosing the fuel evaporative emission suppression device 20. By connecting the fuel filler port connection 16 to the vehicle's fuel filler port 2 and performing pressurization and depressurization tests, it is possible to check for any abnormalities in the fuel evaporative emission suppression device 20. Furthermore, since the charcoal canister inspection device 10 allows inspection of the fuel evaporative emission suppression device 20 by connecting the fuel filler port connection 16 to the vehicle's fuel filler port 2, and does not require access to the charcoal canister 21 or check valve 22 for inspection, the fuel evaporative emission suppression device 20 can be inspected in a short time regardless of the mounting location of the charcoal canister 21 or check valve 22. For example, in vehicle models where the seat cushion and service hole cover must be removed to access the charcoal canister 21 and check valve 22, inspecting the fuel evaporative emission suppression device 20 using conventional methods without the charcoal canister inspection device 10 would take about 10 minutes. However, by connecting the fuel filler port connection 16 of the charcoal canister inspection device 10 to the fuel filler port 2 and inspecting the fuel evaporative emission suppression device 20, the inspection time can be reduced to about 2 minutes. Furthermore, since the charcoal canister inspection device 10 does not require access to the charcoal canister 21 or check valve 22 to inspect the fuel evaporative emission suppression device 20, the inspection procedure for the fuel evaporative emission suppression device 20 can be performed using the same procedure even in vehicle models where the mounting positions of the charcoal canister 21 and check valve 22 differ. [Explanation of Symbols]

[0023] 1 Fuel tank, 2 Fuel filler port, 3 Fuel filler cap, 10 Charcoal canister inspection device, 11 Pressure / depressurization device, 11a Positive pressure port, 11b Negative pressure port, 12a, 12b 1-way valve, 13 4-way valve, 13a, 13b, 13c, 13d Port, 13e Valve body, 14 Pressure gauge, 15 Catch tank, 16 Fuel filler port connection, 20 Fuel evaporative gas emission suppression device, 21 Charcoal canister, 22 Check valve, 22a Positive pressure valve, 22b Negative pressure valve, 23 Solenoid valve, 24 Atmospheric filter.

Claims

[Claim 1] A charcoal canister inspection device that allows inspection of whether there is any abnormality in the fuel evaporative gas emission suppression device by connecting a connection part to the fuel filler port of the vehicle from outside the vehicle, A pressure adjustment device capable of both pressurizing the air pressure inside the fuel tank to a level higher than the opening pressure of the positive pressure valve and depressurizing it to a level lower than the opening pressure of the negative pressure valve, A valve connected to the aforementioned pressure-reducing device and the connection part, which can switch between a state in which the pressure-reducing device increases the pressure inside the fuel tank and a state in which the pressure-reducing device decreases the pressure inside the fuel tank, A catch tank capable of storing fuel is provided between the aforementioned connection and the valve, A pressure gauge capable of measuring the air pressure inside the fuel tank, A charcoal canister inspection device characterized by comprising a pressure indicator that displays the atmospheric pressure measured by the pressure gauge.

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