A fuel pump for a liquid fuel injection system of a motor vehicle is provided. The fuel pump for a fuel injection system includes a low-pressure pump that provides liquid fuel from a fuel tank of the motor vehicle at a low pressure. A high-pressure pump in fluid communication with the low-pressure pump and compresses the liquid fuel from the low pressure to a high pressure for injecting the liquid fuel into an internal combustion engine of the motor vehicle. A pump drive drives the low-pressure pump and the high-pressure pump synchronously with a pump frequency independently from an engine speed of the internal combustion engine of the motor vehicle.

A fuel pump for a liquid fuel injection system of a motor vehicle is provided. The fuel pump for a fuel injection system includes a low-pressure pump that provides liquid fuel from a fuel tank of the motor vehicle at a low pressure. A high-pressure pump in fluid communication with the low-pressure pump and compresses the liquid fuel from the low pressure to a high pressure for injecting the liquid fuel into an internal combustion engine of the motor vehicle. A pump drive drives the low-pressure pump and the high-pressure pump synchronously with a pump frequency independently from an engine speed of the internal combustion engine of the motor vehicle.

A fuel injection pump for a diesel engine, including: a control rack an in a rack chamber formed between a pump head and a pump housing, and configured to adjust a fuel injection amount; a transmission shaft rotatably supported by a transmission shaft hole formed in the pump housing; and a lubricating oil passage formed in the pump housing, and configured to pressure-feed lubricating oil between the transmission shaft and the transmission shaft hole. The transmission shaft has an oil passage therein through which passage the lubricating oil pressure-fed to the lubricating oil passage partially passes, a first opening of the oil passage is communicated with the lubricating oil passage, and a second opening of the oil passage is formed on the outer circumferential surface of an upper portion of the transmission shaft, nearby the control rack.

An intake passage structure for an engine includes an intake port in a cylinder head of the engine, and connected to a combustion chamber to define an intake passage. The intake passage structure further includes a heat insulating member disposed along an inner surface of the intake port, and including a bulge having an upstream end surface which is a portion of an upstream end surface of the heat insulating member, the bulge has a radially outwardly protruding radially outer surface and has an increased wall thickness. The wall thickness of the bulge increases from downstream to upstream of the intake port. The upstream end surface of the bulge includes an injection machine connecting portion facing an injection gate configured to inject resin for forming the heat insulating member into the intake port.

An intake passage structure for an engine includes an intake port in a cylinder head of the engine, and connected to a combustion chamber to define an intake passage. The intake passage structure further includes a heat insulating member disposed along an inner surface of the intake port, and including a bulge having an upstream end surface which is a portion of an upstream end surface of the heat insulating member, the bulge has a radially outwardly protruding radially outer surface and has an increased wall thickness. The wall thickness of the bulge increases from downstream to upstream of the intake port. The upstream end surface of the bulge includes an injection machine connecting portion facing an injection gate configured to inject resin for forming the heat insulating member into the intake port.

A fuel injection pump for a diesel engine, including: a control rack arranged in a rack chamber formed between a pump head and a pump housing, and configured to adjust a fuel injection amount; a transmission shaft rotatably supported by a transmission shaft hole formed in the pump housing; and a lubricating oil passage formed in the pump housing, and configured to pressure-feed lubricating oil between the transmission shaft and the transmission shaft hole. The transmission shaft has an oil passage therein through which passage the lubricating oil pressure-fed to the lubricating oil passage partially passes, a first opening of the oil passage is communicated with the lubricating oil passage, and a second opening of the oil passage is formed on the outer circumferential surface of an upper portion of the transmission shaft, nearby the control rack.

A fuel injection pump for a diesel engine, including: a control rack arranged in a rack chamber formed between a pump head and a pump housing, and configured to adjust a fuel injection amount; a transmission shaft rotatably supported by a transmission shaft hole formed in the pump housing; and a lubricating oil passage formed in the pump housing, and configured to pressure-feed lubricating oil between the transmission shaft and the transmission shaft hole. The transmission shaft has an oil passage therein through which passage the lubricating oil pressure-fed to the lubricating oil passage partially passes, a first opening of the oil passage is communicated with the lubricating oil passage, and a second opening of the oil passage is formed on the outer circumferential surface of an upper portion of the transmission shaft, nearby the control rack.

A pump device for an internal combustion engine, having a high-pressure fuel pump for supplying fuel to a first injection device, having at least one low-pressure inlet, via which the fuel is fed to the high-pressure fuel pump from a low-pressure fuel pump, having at least one low-pressure outlet for conducting the fuel conveyed by the low-pressure fuel pump and fed via the low-pressure inlet to the high-pressure fuel pump out of the high-pressure fuel pump, and having at least one low-pressure port, for conducting fuel conveyed by the low-pressure fuel pump to a second injection device. At least one mixing region mixes the fuel flowing through the low-pressure outlet with fuel fed to the mixing region from the low-pressure fuel pump upstream of the high-pressure fuel pump. The low-pressure port is fluidically connected to the mixing region, and the low-pressure inlet is supplied with fuel from the mixing region.

A pump device for an internal combustion engine, having a high-pressure fuel pump for supplying fuel to a first injection device, having at least one low-pressure inlet, via which the fuel is fed to the high-pressure fuel pump from a low-pressure fuel pump, having at least one low-pressure outlet for conducting the fuel conveyed by the low-pressure fuel pump and fed via the low-pressure inlet to the high-pressure fuel pump out of the high-pressure fuel pump, and having at least one low-pressure port, for conducting fuel conveyed by the low-pressure fuel pump to a second injection device. At least one mixing region mixes the fuel flowing through the low-pressure outlet with fuel fed to the mixing region from the low-pressure fuel pump upstream of the high-pressure fuel pump. The low-pressure port is fluidically connected to the mixing region, and the low-pressure inlet is supplied with fuel from the mixing region.

The invention relates to a high-pressure fuel pump (1), in particular of a common rail injection system of an internal combustion engine, having a pump cylinder head (3), having an intake valve (6) arranged in the pump cylinder head (3) in the direction of a pump cylinder axis, and a high-pressure fuel outlet (5) arranged laterally on the pump cylinder head (3), wherein a protective cap (10, 10a) at least partly covering the high-pressure fuel pump (1) is provided. According to the invention, a high-pressure fuel pump (1) having a protective cap (10, 10a) is provided, in which the protective cap (10, 10a) can be mounted without difficulty on an assembled high-pressure fuel pump (1). This is achieved in that a plug (8) having a lateral lead connection (9) is placed on the electrically operated intake valve (6), and the protective cap (1) is formed in two pieces and has two protective cap parts (11a,11b) that can be fitted to each other, or else in that a plug (8) having a lateral lead connection (9) is placed on the electrically operated intake valve (6), and the protective cap (10a) is formed annularly and has a free clearance slot (19) interrupting the ring.