Denso Corporation

Keiichirou Ishihara

Tomohiro Itoh

Yasuo Kato

Taiki Yasuzaka

Yasuo Katoh

Yuichiro Miura

Ryoyu Kishi

Masahiro Satou

A leakage diagnosis device for an evaporative fuel treatment device includes a first vent valve, a second vent valve, and a pump. The first vent valve is configured to block a first atmospheric passage, which is a main passage of an atmospheric passage and connects a canister with an atmospheric opening. The second vent valve is configured to block a second atmospheric passage, which is a bypass passage of the first atmospheric passage and connects the canister with the atmospheric opening. The pump is provided on a side of the atmospheric opening relative to the second vent valve in the second atmospheric passage, and is configured to pressurize or depressurize the second atmospheric passage. A malfunction diagnosis device performs a malfunction diagnosis based on an output value of a pressure sensor, a current value of the pump, or an output value of an air-fuel ratio sensor.

Malfunction diagnosis device for leakage diagnosis device

A vane pump includes a casing, a rotor, vanes, a motor, and a fixed member. The casing defines a pump chamber therein. The rotor is disposed in the casing and configured to eccentrically rotate relative to the casing. The vanes are configured to rotate together with the rotor to slidably move on an inner surface of the casing. The motor is configured to rotate the rotor. Both the motor and the casing are fixed to the fixed member. The casing has an outer side wall surface and a flange. The flange protrudes outward from the outer side wall surface at an intermediate position between both ends of the pump chamber in a rotational axis direction of the rotor. The flange is fixed to the fixed member at a plurality of positions. The fixed member has a linear expansion coefficient that is different from that of the casing.

Vane pump

A leak hole determination device in an evaporated fuel processing system. The leak hole determination device includes: a first pressure detector for detecting a first pressure in a fuel tank; a second pressure detector for detecting a second pressure in a canister; and a leak hole determiner for determining whether a leak hole is present. The leak hole determiner determines, after a limit pressure timing subsequent to a depressurization operation for depressurizing an inside of the system, whether a leak hole is present by using a difference between a change speed of a first pressure detected by the first pressure detector and a change speed of a second pressure detected by the second pressure detector.

Leak hole determination device of evaporated fuel processing device

A leakage diagnostic device diagnoses leakage of evaporated fuel in an evaporative fuel treatment device. The evaporative fuel treatment device purges evaporated fuel, which is generated in a fuel tank and adsorbed on a canister, to an intake passage. The leakage diagnostic device includes a vent valve that blocks a first atmospheric passage, which connects the canister with an atmospheric opening, and a pump that pressurizes and depressurizes a second atmospheric passage, which is a bypass passage of the first atmospheric passage. The malfunction diagnostic device diagnoses malfunction of the leakage diagnostic device based on an output value of a pressure sensor that detects pressure in a passage connected to the canister.

Malfunction diagnostic device for leakage diagnostic device

A vane pump includes: a casing forming a pump chamber therein; a rotor arranged inside the casing to rotate eccentrically with respect to the casing; and a plurality of vanes configured to rotate with the rotor and slide on an inner side surface of the casing. At least one of Formula (1): l&#x2264;(b/a)&#xd7;k and Formula (2): l&#x2264;(c/a)&#xd7;j is satisfied, where 'a' represents a height of the pump chamber, 'b' represents a height of the rotor, &#x201c;c&#x201d; represents a height of the vane in a rotation axis direction of the rotor, and where &#x201c;l&#x201d; represents a linear expansion coefficient of the casing in the rotation axis direction, &#x201c;k&#x201d; represents a linear expansion coefficient of the rotor in the rotation axis direction, and &#x201c;j&#x201d; represents a linear expansion coefficient of the vane in the rotation axis direction.

The evaporative fuel processing system includes a fuel tank, a canister, a pump, a pressure detection unit, a temperature detection unit, and a leak diagnosis unit a leak diagnosis unit configured to diagnose leak in the diagnostic object based on a first pressure change which is a change in pressure detected by the pressure detection unit when the temperature in the diagnostic object changes, a second pressure change which is a change in pressure detected by the pressure detection unit when the inside of the diagnostic object is pressurized or depressurized by the pump, a detected temperature by the temperature detection unit, a first preparation information and a second preparation information.

Evaporative fuel processing system

A fuel vapor processing device includes a canister, a first purge pipe that forms a first purge path that communicatively connects the inside of the canister and the inside of a fuel tank, a pressure pipe that forms a pressure detection path configured to communicatively connect a first switching valve and a pump, the first switching valve, a sealing valve disposed in the first purge pipe and configured to isolate the inside of the canister from the inside of the fuel tank, a differential pressure sensor, and an ECU. The differential pressure sensor is capable of detecting a difference between a pressure of the first purge path and a pressure of the pressure detection path. The ECU determines presence or absence of a fuel vapor leak while controlling the first switching valve, the pump, and the sealing valve based on a signal output from the differential pressure sensor.

Fuel vapor processing device

A fuel vapor processing device includes a three-way valve having a common valve chamber in which a first valve body, a second valve body, and a third valve body are housed. A single pressure sensor is provided in the common valve chamber. The first valve body enables communication between the common valve chamber and a first valve chamber. The second valve body enables communication between the common valve chamber and a second valve chamber communicating with an inside of the canister. The third valve body enables communication between the common valve chamber and a third valve chamber communicating with an inside of a fuel tank. An ECU controls the three-way valve and a switching valve, and controls driving of a pump to perform fuel vapor leak diagnosis for the fuel tank and the canister, based on a detection value detected by the pressure sensor.

Growing community of inventors

Kariya, Japan

Keiichirou Ishihara