Toyota Jidosha Kabushiki Kaisha

Naoki Kurata

Daichi Yamazaki

Tatsuhiko Akita

Mitsuto Sakai

Masanori Sugiyama

Naoto Suzuki

Toshio Inoue

Keita Fukui

Katsuhiko Yamaguchi

Mamoru Tomatsuri

Keiko Hasegawa

Kazuyuki Tokuda

Hiroshi Inoue

Kazuhiro Asayama

Tomoji Ishikawa

A high-pressure pump () is provided which is drivingly connected to an engine output shaft () and delivers fuel to an injector () through a delivery pipe () based on the rotation of the output shaft (). The high-pressure pump () includes an electromagnetic valve () that adjusts, based on the engine operating state, a fuel delivery amount within an adjustable range that changes according to a rotation speed of the engine output shaft (). When an abnormality is detected in the electromagnetic valve (), the rotation speed of the engine output shaft () is restricted to equal to or less than a reference engine speed (NT).

Fuel supply apparatus and fuel supply method of an internal combustion engine

An engine ECU stores a map in which three regions, that is, a high-temperature region, a low-temperature region, and a region therebetween, are prescribed. The pre-feed time T set when the present condition falls in the region is the longest. An engine ECU executes a program that includes the step of detecting an engine cooling water temperature THW when the start-up of the engine is requested, the step of executing the pre-feed until the fuel pressure P becomes equal to or greater than a fuel pressure threshold value P(TH), and the step of starting the cranking when the fuel pressure P becomes equal to or greater than the fuel pressure threshold value P(TH). Thus, the bad start-up caused by fuel vapor is avoided without operating the fuel pump unnecessarily for a long time.

Start-up control device and start-up control method for internal combustion engine

A pulsation damper is provided between and in series with a low pressure fuel system pipe and a high pressure pump of a fuel supply system. During startup of an engine, low pressure fuel supplied via the low pressure fuel system pipe is injected from an intake passage fuel injector. When the fuel pressure is equal to or less than a fuel pressure at which good startability can be maintained, the pulsation damper closes off communication between the high pressure fuel system pipe and the low pressure fuel system pipe using the spring force of a spring.

Fuel supply system for an internal combustion engine

An engine ECU stores a map in which a region at high temperature and high pressure, a region at low temperature and low pressure, and a region provided therebetween are defined by the relationship between the temperature and pressure of fuel and the saturation fuel vapor pressure of the fuel. The engine ECU executes a program including the following steps: when start-up of the engine is requested, detecting the engine cooling water temperature and the fuel pressure; if the detection results fall into the region, setting a pre-feed time; pre-feeding until the fuel pressure reaches a desired fuel pressure threshold; and when the fuel pressure reaches the fuel pressure threshold, starting cranking. In this way, start-up failure due to fuel vapor can be avoided without unnecessarily actuating a fuel pump.

The engine ECU executes a program including the step of detecting an engine coolant temperature, the step of detecting an engine speed and an engine load, the step of estimating a temperature at a tip end of an in-cylinder injector based on the engine coolant temperature, the engine speed and the engine load, and, when the temperature at the tip end is greater than a guaranteed temperature, the step of calculating a drive duty of a high-pressure fuel pump that ensures a decrease of the temperature at the tip end of the in-cylinder injector to the guaranteed temperature, and the step of controlling the high-pressure fuel pump using the drive duty.

Fuel supply apparatus for internal combustion engine

A low-pressure delivery pipe provided with intake manifold injectors, a fuel pressure regulator, a high-pressure fuel pump, a high-pressure delivery pipe provided with in-cylinder injectors, and an electromagnetic relief valve are connected in series at the downstream of a low-pressure fuel pump that discharges a fuel within a fuel tank at a prescribed pressure. Since the low-pressure delivery pipe is arranged downstream of the low-pressure fuel pump, the fuel pressure within the low-pressure delivery pipe is lowered upon stop of vehicle operation, in response to stop of the low-pressure fuel pump. The fuel pressure within the high-pressure delivery pipe is also lowered in response to stop of the low-pressure fuel pump, by opening the electromagnetic relief valve upon stop of vehicle operation. Thus, oil tightness of the injectors during the stop of vehicle operation is ensured.

Fuel supply system for internal combustion engine

A fuel supply system according to the present invention includes a first delivery pipe for intake passage injection and a second delivery pipe for cylinder injection. The second delivery pipe is provided with a relief valve. A fuel discharge section of the relief valve is connected to the first delivery pipe via a relief passage.

Fuel supply system of internal combustion engine and internal combustion engine

A high pressure pump for decreasing an initial axial force of a clamping bolt and preventing distortion of a sealing surface and a cylinder form. The high pressure pump has an intermediate member including a cylinder body. The cylinder body has a pressurizing chamber communicated with a cylinder accommodating a plunger. Fluid in the pressurizing chamber is pressurized by reciprocating the plunger. The intermediate member is arranged between a cover and a flange and clamped by a clamping bolt. The clamping bolt has an exposed area at its axially central area where the entire periphery of the clamping bolt is exposed from the cover and the flange. One or both of the cover and the flange clamp the intermediate member with a flexing elastic force.

High-pressure fuel pump and assembly structure of high-pressure pump

An ECU for an internal combustion engine predicts change in the driving state of the engine when switching from port injection mode to in-cylinder injection mode. In accordance with the prediction, the ECU actuates a high-pressure pump before entering the in-cylinder injection mode to pressurize the fuel supplied to an air-intake passage injector.

Internal combustion engine controller

A fuel injector for an internal combustion engine including an in-cylinder fuel injection valve and an intake port fuel injection valve. An ECU controls an electromagnetic valve to keep a fuel inlet of a high pressure pump closed during an intake port injection mode during which fuel is injected only from an intake port fuel injection valve. As a result, even if the plunger reciprocates in the high pressure pump, fuel does not flow between the high pressure pump and a low pressure fuel path. Thus, pressure pulsation that would be caused by the operation of the high pressure pump does not occur in low pressure fuel.

Fuel injector for internal combustion engine

An ECU calculates the difference between the fuel pressure in a high-pressure distribution pipe and a target pressure when fuel is injected only from an air-intake passage injector. The ECU determines the bulk modulus of fuel that is associated with the coolant temperature. The ECU determines the amount of fuel that is to be discharged from a high-pressure pump based on the pressure difference and the bulk modulus. Then, the ECU actuates the high-pressure pump in accordance with the determined discharge amount.

A cam for driving a high-pressure fuel pump has a cam profile that is asymmetric for the suction stroke and the ejection stroke. The cam profile is set so that the cam angle for the ejection stroke is greater than the cam angle for the suction stroke. Therefore, even when the cam drive shaft is rotating at a constant speed, the duration of the ejection stroke becomes longer than the duration of the suction stroke. That is, the changing speed of the capacity of a pressurizing chamber becomes less during the ejection stroke than during the suction stroke.

Growing community of inventors

Nishikamo-gun, Japan

Naoki Kurata