High Pressure Pump and System The invention relates to a high pressure pump for the delivery of a fluid and a system for the delivery of a fluid.

In today's automotive engine systems, there is an increased demand for low cost, direct injection. In common rail injection systems, the fuel is delivered by means of a high pressure pump from a fuel tank to a fuel rail which serves as a storage reservoir for the fuel. The fuel is under high pressure in the fuel rail (or common rail) and can be injected directly into the cylinders via injection valves connected to the rail.

It is desirable to provide a high pressure pump and a system for the delivery of a fluid which is cost-effective.

According to an aspect of the invention a high pressure pump for the delivery of a fluid comprises a pump body. The high pressure pump further comprises a piston. The piston is axially movable within the pump body and comprises a first part and a second part. The first part is arranged within the pump body and the second part is arranged outside the pump body. The pump body is couplable with a combustion engine such that the second part of the piston extends into the combustion engine. The pump body is provided with as many fluid outputs as the combustion engine comprises cylinders. The pump is designed for coupling each fluid output directly with one cylinder of the combustion engine via a pipe.

The pump body is couplable with the combustion engine, particularly with an engine block or with a cylinder head of the combustion engine, and when the pump body is coupled with the combustion engine the second part of the piston is arranged such that it is axially movable in an opening of the engine block of the combustion engine. The high pressure pump is a plug-in pump. The high pressure pump is couplable directly in the engine block and mountable with the engine block.

According to further aspects, the piston is coupled with a roller tappet. The roller tappet is couplable with the cam or crank or balancer shaft of the combustion engine. The cam or crank or balancer shaft is arranged to move the roller tappet and the piston. The roller tappet is in direct contact with the opening of the engine block. The roller tappet slides over the walls of the opening. In the opening in the engine block ensures the axial movement of the roller tappet. Since the pump body is provided mainly for the guiding of the fluid and not for the guiding of the piston, the high pressure pump is provided with less weight and is very compact. Further, the pump is cost-effective. With the high pressure pump a direct coupling of the pump with injectors for injecting fluid into the combustion chambers is possible.

There is no common rail arranged hydraulically between the injectors and the pump. The pump is designed such that each injector comprises its own fluid delivery path from the pump to the injector. Outside the pump the injectors are hydraulically independent from each other.

According to a further aspect of the invention the pump body surrounds one single piston chamber for the piston, one single fluid inlet and two or three fluid outlets. The fluid inlet and the fluid outlets each are hydraulically coupled with the piston chamber . According to further aspects, the pump comprises a pressure sensor coupled with the pump body for determining a value of the fluid pressure at the fluid outlets. Thus, the pump is arranged to provide a given value for the pressure for the injectors precisely.

According to a further aspect of the invention, a system for the delivery of a fluid comprises a high pressure pump for the delivery of a fluid. Each fluid outlet of the pump is connected to a pipe and each pipe is directly couplable with an injector for injecting fluid into the combustion chamber of the combustion engine .

According to further aspects of the invention the pump is coupled upstream with an electrically driven pump. For example, the electrically driven pump is an in-tank pump that is arranged inside a fluid tank. For example, the system comprises no further internal transfer pump. The system is a low-cost and low-weight compact pump system. There is no need for a common rail between the high pressure pump and the injectors. The injectors are fed directly by the pump. The pump is designed such that each injector comprises its own fluid delivery path from the pump to the injector. Outside the pump the injectors are hydraulically independent from each other.

Reference will now be made in detail to the preferred embodiments, examples of which are illustrated in the accompanying drawings. The same elements, elements of the same type and elements having the same effect may be provided with the same reference symbols in the figures.

Figure 1: schematically shows high pressure pump according to an embodiment, Figures 2A and 2B: schematically show high pressure pump according to an embodiment,

Figure 3: schematically shows high pressure pump according to an embodiment, and

Figure 4: schematically shows a system for the delivery of a fluid according to an embodiment . Figure 1 schematically shows a high pressure pump 100 according to an embodiment.

The high pressure pump 100 comprises a pump body 101 that surrounds openings for the guiding of fluid. The pump body 101 comprises a fluid inlet 112. The fluid inlet is couplable with an electric pump. The electric pump feeds the fluid to the inlet 112 of the pump body 101.

A piston 102 is axially movable relative to the pump body 101 in a piston chamber 111. Due to the movement of the piston 102 relative to the pump body 101 fluid is sucked in through the inlet 112 into the pump body 101 and ejected through fluid outlets 105.

The piston comprises a first part 103 that is arranged within the pump body 101. The first part 103 is at least partly in contact with the fluid during operation of the pump 100. The piston 102 comprises a second part 104 that is arranged outside the pump body 101. The second part 104 is coupled with a roller tappet 117. The roller tappet 117 is coupled to a drive shaft 127 of a combustion engine. The drive shaft 127 may be a cam or a crank or a balancer shaft for the movement of the roller tappet 117 and the piston 102 axially relative to the pump body 101. The pump body 101 is coupled to an engine block 129 of the combustion engine. The engine block 129 surrounds an opening 128. The roller tappet 117 and the second part 104 of the piston 102 are arranged in the opening 128. The roller tappet 117 is in direct contact with the engine block 129. The roller tappet 117 and the drive shaft 127 are lubricated with engine oil.

A pressure sensor 116 is arranged at the pump body 101 and hydraulically connected to the piston chamber 111 for determining the value of the fluid pressure at the fluid outlet 105.

The pump 100 comprises as many fluid outlets as the combustion engine comprises cylinders. For example, the pump 100 comprises one outlet 105. As shown in Figures 2A and 2B, according to further aspects the pump 100 comprises two fluid outlets 105 and 106. As further shown in Figure 3, according to further aspects, the pump 100 comprises three fluid outlets 105, 106, 107. According to further aspects, the pump comprises more than three fluid outlets, for example four or more fluid outlets.

Each fluid outlet 105, 106, 107 is connected to a pipe as exemplarily shown for three outputs in Figure 4. Each pipe 108, 109, 110 is coupled with an injector 113, 114, 115. The pump 100 delivers fluid to the injectors 113, 114, 115. The injectors are arranged to inject the fluid into combustion chambers of the combustion engine. In the example of Figure 4 the combustion engine comprises three combustion chambers.

One injector of the injectors 113, 114, 115 is arranged in one combustion chamber respectively. There is no common rail between the pump 100 and the injectors 113, 114 and 115. The injectors 113, 114, 115 each are directly coupled with the pump 100 via the pipes 108, 109, 110. According to further aspects, the pump 100 comprises a volume control valve for controlling the volume of fluid delivered to the combustion engine. The pump 100 is installed directly in the engine block 129. The roller tappet 117 slides over the walls of the engine block 129 in the opening 128. The opening 128 ensures the axial movement of the roller tappet 117. Thus, a lighter and compact system for the delivery of the fluid is provided. Since there is no need for a common rail, the system is cost-effective. An internal transfer pump may be replaced by the electric in-tank pump that is hydraulically coupled to the inlet 112 of the pump body 101.