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]

[0001] The present invention relates to a charcoal canister inspection device for inspecting an evaporative emission control device mounted on a vehicle for abnormalities. [Background technology]

[0002] Gasoline engine vehicles, which have a high fuel volatility, are equipped with a fuel evaporative emission control device to prevent gasoline vapor that evaporates in the fuel tank from being emitted into the atmosphere. The fuel evaporative emission control device consists of a charcoal canister for absorbing gasoline vapor, a check valve connected between the fuel tank and the charcoal canister, and other piping. In Japan, fuel evaporative emission control devices are subject to statutory periodic inspections of automobiles. Therefore, private passenger cars must be inspected every two years, and private freight cars and business vehicles must be inspected once a year for blockages and damage to the charcoal canister, the function of the check valve, and damage to the piping.

[0003] Patent Document 1 discloses a vehicle equipped with a diagnostic device capable of diagnosing whether there is an abnormality in a fuel evaporative emission control device. Such diagnostic devices are installed in vehicles only in regions such as North America where the installation of such devices is required by law. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2002-213305 A Summary of the Invention [Problem to be solved by the invention]

[0005] In vehicles that are not equipped with a diagnostic device that can diagnose whether there is an abnormality in the fuel evaporative emission control device, it is necessary to remove the hoses connected to the charcoal canister and the check valve, and then blow air into the charcoal canister to check whether it is clogged and blow air into the check valve to check whether it is working properly at each statutory periodic inspection. However, in vehicles where the charcoal canister and the check valve are located near the fuel tank, it is necessary to remove the rear seat cushion and the service hole cover in order to access these inspection parts. Therefore, these inspection procedures are time-consuming and take about 10 minutes. Furthermore, there is a problem that the inspection procedures differ depending on the installation position of the charcoal canister, etc., because different parts need to be removed to access the inspection parts in vehicles with different installation positions of the charcoal canister, etc.

[0006] Therefore, an object of the present invention is to provide a charcoal canister inspection device that can quickly inspect a fuel evaporative emission control device for abnormalities, regardless of the installation position of the charcoal canister, etc., in a vehicle that is not equipped with a diagnostic device for diagnosing the fuel evaporative emission control device. [Means for solving the problem]

[0007] The charcoal canister inspection device of the present invention is a charcoal canister inspection device that can be connected to the fuel filler port of a vehicle to inspect for abnormalities in a fuel evaporative emission control device, and is characterized by comprising a pressurizing / depressurizing device that can at least one of pressurizing the air pressure in the fuel tank so that it is higher than the opening pressure of the positive pressure valve and reducing the air pressure in the fuel tank so that it is lower than the opening pressure of the negative pressure valve, a pressure gauge that can measure the air pressure in the fuel tank, and a pressure indicator that displays the air pressure measured by the pressure gauge. Effect of the Invention

[0008] The present invention provides a charcoal canister inspection device that can quickly inspect a fuel evaporative emission control device for abnormalities, regardless of the installation position of the charcoal canister, in a vehicle that is not equipped with a diagnostic device for diagnosing the fuel evaporative emission control device. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram showing the configuration of a charcoal canister inspection device according to an embodiment of the present disclosure. [Diagram 2] FIG. 11 is a diagram showing the air flow when the air pressure inside the fuel tank is increased to a level higher than the opening pressure of the positive pressure valve in a pressurization test. [Diagram 3] FIG. 11 is a diagram showing the air flow when the air pressure in the fuel tank is reduced to a pressure lower than the opening pressure of the negative pressure valve in a decompression test. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, the charcoal canister inspection device 10 of this embodiment will be described with reference to FIGS. 1 to 3. FIG. 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 an abnormality in the evaporative gas emission suppression device 20 by performing a pressurization test in which the air pressure in the fuel tank 1 is pressurized so that it is higher than the valve opening pressure of the positive pressure valve 22a, and a depressurization test in which the air pressure in the fuel tank 1 is depressurized so that it is lower than the valve opening pressure of the negative pressure valve 22b. FIG. 2 is a diagram showing the air flow in the evaporative gas emission suppression device 20 when the air pressure in the fuel tank 1 is pressurized so that it is higher than the valve opening pressure of the positive pressure valve 22a in the pressurization test. FIG. 3 is a diagram showing the air flow in the evaporative gas emission suppression device 20 when the air pressure in the fuel tank 1 is depressurized so that it is lower than the valve opening pressure of the negative pressure valve 22b in the depressurization test.

[0011] 1, the charcoal canister inspection device 10 includes a pressurizing / depressurizing 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 filler connection portion 16. The four-way valve 13 has four ports 13a, 13b, 13c, and 13d.

[0012] By operating the pressurizing / depressurizing device 11, it is possible to generate an air pressure higher than the valve opening pressure of the positive pressure valve 22a at the positive pressure port 11a, and generate an air pressure lower than the valve opening pressure of the negative pressure valve 22b at the negative pressure port 11b. The positive pressure port 11a of the pressurizing / depressurizing device 11 is connected to the port 13a of the 4-way valve 13 via the 1-way valve 12a. Since the 1-way valve 12a is a check valve, air can flow from the positive pressure port 11a of the pressurizing / depressurizing device 11 to the port 13a of the 4-way valve 13, but air cannot flow from the port 13a of the 4-way valve 13 to the positive pressure port 11a of the pressurizing / depressurizing device 11. The negative pressure port 11b of the pressurizing / depressurizing device 11 is connected to the port 13b of the 4-way valve 13 via the 1-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 toward the negative pressure port 11b of the pressurizing / pressurizing device 11, but air cannot flow from the negative pressure port 11b of the pressurizing / pressurizing device 11 toward the port 13b of the four-way valve 13.

[0013] Port 13c of 4-way valve 13 is open to the atmosphere. Port 13d of 4-way valve 13 is connected to fuel filler port connection part 16 via catch tank 15. As shown in FIGS. 2 and 3, fuel filler port connection part 16 can be connected to fuel filler port 2 of the vehicle with fuel filler cap 3 removed from the fuel filler port 2 of the vehicle. When fuel filler port connection part 16 is connected to the fuel filler port 2 of the vehicle in this manner, communication is established from port 13d of 4-way valve 13 to the fuel tank 1 of the vehicle. Then, with fuel filler port connection part 16 connected to the fuel filler port 2 of the vehicle, the fuel filler cap 3 of the vehicle can be attached to the back of fuel filler port connection part 16. Since the fuel filler cap 3 has a built-in relief valve, when the fuel filler connection part 16 is connected to the fuel filler 2 of the vehicle and the fuel filler cap 3 is attached to the back of the fuel filler connection part 16, the air pressure in the fuel tank 1 can be prevented from becoming excessively high or low even when the air pressure in the fuel tank 1 is increased or decreased by a pressurization test or a depressurization test. Also, by providing a catch tank 15 between the port 13a of the four-way valve 13 and the fuel filler connection part 16 as shown in Fig. 1, it is possible to prevent fuel from flowing back from the fuel tank 1 to the four-way valve 13 side via the catch tank 15 when the air pressure in the fuel tank 1 is decreased by a depressurization test with the fuel tank 1 in a full state.

[0014] As shown in Fig. 1, a pressure gauge 14 is provided between port 13d of four-way valve 13 and catch tank 15. When fuel filler port connection part 16 is connected to a fuel filler port 2 of a vehicle and fuel filler cap 3 is attached to the back of fuel filler port connection part 16 as shown in Figs. 2 and 3, pressure gauge 14 can measure the air pressure inside fuel tank 1 of the vehicle. Pressure gauge 14 has a display part that displays the measured air pressure. In other words, pressure gauge 14 has both the function of a pressure gauge that measures the air pressure inside fuel tank 1 and the function of a pressure indicator that displays the measured air pressure.

[0015] The position of the valve element 13e of the four-way valve 13 can be switched between two positions: the position shown by the solid line in Fig. 1 and the position shown by the dashed line in Fig. 1. When the valve element 13e of the four-way valve 13 is in the position shown by the solid line in Fig. 1, port 13a communicates with port 13d, and port 13b communicates with port 13c. When the valve element 13e of the four-way valve 13 is in the position shown by the dashed line in Fig. 1, port 13a communicates with port 13c, and port 13b communicates with port 13d.

[0016] As shown in FIGS. 2 and 3, the fuel evaporative emission control device 20 includes a charcoal canister 21, a check valve 22, an electromagnetic valve 23, and an air filter 24. The charcoal canister 21 is connected to the fuel tank 1 via the check valve 22. The charcoal canister 21 is connected to the intake system of the engine via the electromagnetic valve 23. The charcoal canister 21 is connected to the atmosphere via the air 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 FIG. 2 when the air pressure in the fuel tank 1 becomes a positive pressure higher than a preset valve opening pressure. The negative pressure valve 22b opens as shown in FIG. 3 when the air pressure in the fuel tank 1 becomes a negative pressure lower than the preset valve opening pressure.

[0017] 2-3, with the solenoid valve 23 closed, the charcoal canister inspection device 10 can inspect the vehicle's fuel evaporative emission control device 20 for abnormalities by performing a pressurization test and a depressurization test with the fuel filler port connection part 16 connected to the fuel filler port 2 of the vehicle and the fuel filler cap 3 attached to the back of the fuel filler port connection part 16. In this pressurization test and depressurization test, the pressurization and depressurization device 11 functions as a pressurization and depressurization device that pressurizes the air pressure in the fuel tank 1 during the pressurization test so that it is higher than the valve opening pressure of the positive pressure valve 22a, and that depressurizes the air pressure in the fuel tank 1 during the depressurization test so that it is lower than the valve opening pressure of the negative pressure valve 22b.

[0018] When a pressurization test is performed, the valve body 13e of the 4-way valve 13 is set to the position shown by the solid line in Fig. 1, and the pressurization / depressurization device 11 is operated to generate an air pressure in the positive pressure port 11a that is higher than the valve opening pressure of the positive pressure valve 22a. Then, since the port 13a and the port 13d of the 4-way valve 13 are connected to each other, air flows from the positive pressure port 11a of the pressurization / depressurization device 11 to the port 13a of the 4-way valve 13 via the 1-way valve 12a, flows from the port 13a to the port 13d inside the 4-way valve 13, and flows from the port 13d of the 4-way valve 13 into the fuel tank 1 via the catch tank 15 and the fuel filler port connection part 16. Then, as the air flows into the fuel tank 1 from the positive pressure port 11a of the pressurization / depressurization device 11 in this way, the air pressure in the fuel tank 1 is pressurized to be higher than the valve opening pressure of the positive pressure valve 22a. In this way, even when the air pressure inside the fuel tank 1 is pressurized to be higher than the valve opening pressure of the positive pressure valve 22a, the one-way valve 12a can maintain the positive pressure inside the fuel tank 1 so that it does not escape to the pressurizing / depressurizing device 11 side.

[0019] When the pressure in the fuel tank 1 is increased to a value higher than the opening pressure of the positive pressure valve 22a by operating the pressure increase / reduction device 11 in this manner, the positive pressure valve 22a of the check valve 22 opens, and the air in the fuel tank 1 passes through the check valve 22 and the charcoal canister 21, and is released to the atmosphere from the atmospheric filter 24, as shown by the arrow in Fig. 2. Therefore, the pressure in the fuel tank 1 decreases 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 pressurization test, if the pressure value displayed on the pressure gauge 14 decreases to a predetermined value or lower within a predetermined time range after the pressure increase / reduction device 11 is operated to increase the pressure in the fuel tank 1 to a value higher than the opening pressure of the positive pressure valve 22a, it can be determined that the charcoal canister 21, the atmospheric filter 24, and the piping are not clogged, and the positive pressure valve 22a of the check valve 22 is also operating normally. If the pressure indication on the pressure gauge 14 does not drop below a predetermined value within a predetermined time period, it can be determined that there is a blockage in the charcoal canister 21, the atmospheric filter 24, or the piping, or that a malfunction has occurred in the positive pressure valve 22a of the check valve 22.

[0020] When a pressure reduction test is performed, the valve body 13e of the four-way valve 13 is set to the position shown by the broken line in Fig. 1, and the pressurizing and depressurizing device 11 is operated to generate an air pressure in the negative pressure port 11b lower than the valve opening pressure of the negative pressure valve 22b. Then, since the port 13b and the port 13d of the four-way valve 13 are connected to each other, the air in the fuel tank 1 flows through the fuel filler port connection portion 16 and the catch tank 15 to the port 13d of the four-way valve 13, flows from the port 13d to the port 13b inside the four-way valve 13, and flows from the port 13b of the four-way valve 13 to the negative pressure port 11b of the pressurizing and depressurizing device 11 through the one-way valve 12b. Then, by the air flowing out from the fuel tank 1 to the negative pressure port 11b of the pressurizing and depressurizing device 11 in this way, the air pressure in the fuel tank 1 is reduced to be lower than the valve opening pressure of the negative pressure valve 22b. Even when the air pressure inside the fuel tank 1 is reduced to be lower than the opening pressure of the negative pressure valve 22b in this manner, the one-way valve 12b prevents air from flowing in from the pressurizing / depressurizing device 11 side, so that the negative pressure inside the fuel tank 1 can be maintained.

[0021] When the pressure in the fuel tank 1 is reduced below the valve opening pressure of the negative pressure valve 22b by operating the pressure increase / reduction device 11 in this manner, the negative pressure valve 22b of the check valve 22 opens, and air flows from the atmospheric filter 24 through the charcoal canister 21 and the check valve 22 into the fuel tank 1, as shown by the arrow in Fig. 3. Therefore, the pressure in the fuel tank 1 rises from a pressure lower than the valve opening pressure of the negative pressure valve 22b toward the valve opening pressure of the negative pressure valve 22b. In the pressure reduction test, if the pressure value displayed on the pressure gauge 14 rises to or above a predetermined value within a predetermined time range after the pressure increase / reduction device 11 is operated to reduce the pressure in the fuel tank 1 below the valve opening pressure of the negative pressure valve 22b, it can be determined that there is no clogging in the charcoal canister 21, the atmospheric filter 24, or the piping, and that the negative pressure valve 22b of the check valve 22 is also operating normally. If the pressure indication on the pressure gauge 14 does not rise to or exceed a predetermined value within a predetermined time period, it can be determined that there is a blockage in the charcoal canister 21, the atmospheric filter 24, or the piping, or that a malfunction has occurred in the negative pressure valve 22b of the check valve 22.

[0022] In a vehicle that is not equipped with a diagnostic device for diagnosing the evaporative emission control device 20, the charcoal canister inspection device 10 can inspect the evaporative emission control device 20 for any abnormalities by connecting the fuel filler port connection part 16 to the fuel filler port 2 of the vehicle in this manner and conducting a pressurization test and a depressurization test. Furthermore, the charcoal canister inspection device 10 can inspect the evaporative emission control device 20 by connecting the fuel filler port connection part 16 to the fuel filler port 2 of the vehicle, and since there is no need to access the charcoal canister 21 or the check valve 22 for inspection, the inspection of the evaporative emission control device 20 can be completed in a short time regardless of the mounting positions of the charcoal canister 21 or the check valve 22. For example, in a vehicle model in which the seat cushion and service hole cover must be removed to access the charcoal canister 21 and the check valve 22, inspecting the evaporative emission control device 20 using a conventional method without using the charcoal canister inspection device 10 takes about 10 minutes, but by connecting the fuel filler port connection part 16 of the charcoal canister inspection device 10 to the fuel filler port 2 and inspecting the evaporative emission control device 20, the inspection time can be shortened to about 2 minutes. Furthermore, because the charcoal canister inspection device 10 does not require access to the charcoal canister 21 or the check valve 22 to inspect the evaporative emission control device 20, the inspection work for the evaporative emission control device 20 can be performed using the same work procedure even in vehicle models in which the charcoal canister 21 and the check valve 22 are installed in different positions. [Explanation of symbols]

[0023] 1 fuel tank, 2 fuel filler, 3 fuel filler cap, 10 charcoal canister inspection device, 11 pressure booster / decompressor, 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 connection part, 20 fuel evaporative emission control device, 21 charcoal canister, 22 check valve, 22a positive pressure valve, 22b negative pressure valve, 23 solenoid valve, 24 air filter.

Claims

[Claim 1] A charcoal canister inspection device that can be connected to a fuel filler port of a vehicle to inspect whether there is an abnormality in a fuel evaporative emission control device, a pressure increasing / decreasing device capable of at least one of increasing the air pressure in the fuel tank to a pressure higher than the valve opening pressure of the positive pressure valve and decreasing the air pressure in the fuel tank to a pressure lower than the valve opening pressure of the negative pressure valve; a pressure gauge capable of measuring the air pressure inside the fuel tank; and a pressure indicator that displays the air pressure measured by the pressure gauge.

Images