JP2006138309A - High pressure pump for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high pressure pump for eliminating the need for frequent maintenance involving a great burden, and to provide an internal combustion engine using the same. <P>SOLUTION: The pump for supplying compressed fuel to the internal combustion engine comprises a body, a compartment provided in the body, a pump part provided in the compartment in a movable fashion for increasing the pressure of fuel, a fuel supply means for distributing the fuel into the pump part, and an inlet provided in the body and fluidically connected to the compartment so that the fuel is supplied directly from an external supply source to the compartment for lubricating/cooling the pump. The fuel supply means includes another inlet which is provided in the body and fluidically connected to the pump part so that the fuel received directly from the external supply source is supplied to the pump part. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a high pressure pump and compression device for an internal combustion engine.

  Fuel injection systems comprising a tank for storing fuel and a system for compressing fuel are known in the field of internal combustion engines. The fuel compression system is fluidly connected to the tank and is provided to allow the engine to use fuel at a preset pressure.

  In particular, the compression system generally comprises a suction pump for the fuel contained in the tank and a compression device. This compression device is for making fuel available to a plurality of injection parts connected to each combustion chamber of an engine via a common pipe.

  By operating the compression system described above, the suction pump will draw fuel from the tank and make the fuel available at low pressure to the compression device for further compression. This compression device is for setting the optimum pressure value for injecting fuel into the combustion chamber.

  More specifically, the compression apparatus includes a high pressure pump and a distribution circuit. This distribution circuit is installed between the suction pump and the high-pressure pump, and makes fuel available to the high-pressure pump.

  More specifically, this high pressure pump has a generally cast iron body with a hollow chamber (referred to as a guard) provided therein.

  The guard is composed of a plurality of pump parts designed to compress fuel, a part of a shaft for controlling the pump part driven by an internal combustion engine or an auxiliary motor, and each pump part from the shaft. And a cam designed to convey the movement.

  In particular, each pump section has a suction valve for regulating the delivery of compressed fuel and a discharge valve for discharging the compressed fuel to the engine by means of a distribution circuit.

  In known high-pressure pumps, in addition to being compressed in the pump section, fuel lubricates and cools the guard, shaft, cam, and pump section.

  For this purpose, a pipe for delivering fuel from the distribution circuit traverses the body of the high-pressure pump and connects this guard with a single inlet formed in the body.

  In a first embodiment of a known type of high-pressure pump, a plurality of pipes for feeding each pump part branch off from this delivery pipe at a position between this inlet and the guard, up to each pump part. Extend.

  In another embodiment, the delivery pipe is not branched at all and is provided with a plurality of supply pipes extending to each pump section.

  In both of the above-described embodiments, each supply pipe is formed in the main body of the high-pressure pump, and is supplied to the corresponding pump unit via the corresponding suction valve by each supply pipe.

  In a known type of compression device, when the fuel passes through the intake valve of the pump section, it is heated by conduction by a member provided in the main body of the high-pressure pump or the guard, and the fuel becomes high temperature.

  As a result, a serious leak occurs that results in a decrease in the efficiency of the high pressure pump. In addition, especially at high speeds, the engine gives a rotating action to the fuel present in the guard, thereby obstructing the flow of fuel towards the pump part, further reducing the efficiency of the high-pressure pump. End up.

  Furthermore, for embodiments in which the fuel reaches the pump section after the guard has been cooled directly, the possible mechanical scraping, where the fuel is generated by the detachment of parts of the parts in contact with each other. May be contaminated with litter and impurities. Under such circumstances, there is a possibility of causing an erroneous operation of the high-pressure pump, and it is necessary to perform maintenance frequently because of a heavy load.

  The present invention aims to provide a high-pressure pump for an internal combustion engine that does not have the disadvantages associated with known high-pressure pumps and the aforementioned disadvantages.

  The above objective can be achieved by the present invention relating to a high-pressure pump as defined in claim 1.

  Similarly, the invention relates to a compression device for an internal combustion engine as defined in claim 3.

  In order to better understand the present invention, preferred embodiments are described below. This embodiment is given by way of non-limiting example only with reference to the accompanying drawings. The accompanying drawings partially show an injection system for an internal combustion engine having a high pressure pump and a compression device.

  With reference to the accompanying drawings, an injection system for an internal combustion engine (known per se and not shown) is designated 1 throughout.

  This system 1 is illustrated to the extent required for an understanding of the present invention. The system 1 is basically designed to compress a fuel 2 and a fuel 2 connected to the tank 2 for fuel and taken in from the tank 2 and is internally combusted at a desired pressure. And a compression system 3 that can be made available to the engine.

  In particular, the compression system 3 comprises a suction pump 4 immersed in the tank 2 and a compression device 5 fluidly connected to the suction pump 4. The compression device 5 is for compressing fuel to a preset pressure value.

  The compression device 5 comprises a circuit 6 for distributing fuel, fluidly connected to the suction pump 4, and a high-pressure pump 7 supplied by this circuit 6 and fluidly connected to the internal combustion engine. .

  The circuit 6 is made of a material having low heat conductivity, is fluidly disposed between the suction pump 4 and the high-pressure pump 7, and supplies a pipe 9 connected to the suction pump 4 and fuel to the high-pressure pump 7. It is preferable to include one or more supply pipes 8 (two are shown in this case) and a pipe 10 for lubrication / cooling of the high-pressure pump 7.

  In particular, the pipe 9 connects the T-shaped coupling part 11 and the suction pump 4. The T-shaped coupling portion 11 is separated into a lubrication / cooling pipe 10 and a connection pipe 30.

  The connecting pipe 30 ends at a position corresponding to another T-shaped coupling portion 12, and the supply pipe 8 is separated from the T-shaped coupling portion 12. The supply pipe 8 extends to the high pressure pump 7.

  The supply pipe 8 is outside the high-pressure pump 7 and is preferably separated from each other and further separated from the lubrication / cooling pipe 10.

  The flow rate adjusting device 23 having a constant cross-sectional area is further provided on the lubrication / cooling pipe 10 at a position between the T-shaped coupling portion 11 and the high-pressure pump 7.

  The above-described flow rate adjusting device 23 is sized based on the design characteristics of the high pressure pump 7 that can pass a fuel having a flow rate sufficient to lubricate / cool the high pressure pump 7.

  The high-pressure pump 7 includes at least one pump unit 13 (two are provided in this case). The pump unit 13 is provided to compress the fuel to a preset pressure, and is operated via a cam 18 by a shaft 19 operably connected to the internal combustion engine.

  In more detail, each pump section 13 is provided with an intake valve 14 for distributing the compressed fuel coming from the corresponding supply pipe 8 and for releasing the compressed fuel to the outside with respect to the internal combustion engine. The discharge valve 15 is provided.

  Further, each pump unit 13 is connected to each delivery pipe 25 downstream of the discharge valve 15. The delivery pipe 25 is installed at least partially outside the high-pressure pump 7.

  More specifically, the high-pressure pump 7 is generally defined by a body 16 made of a thermally conductive material and further having a cavity (referred to in the latter part by the term “guard” 17) formed therein. Is done. The guard 17 has a pump portion 13, a cam 18, and an end portion of the shaft 19.

  More specifically, the guard 17 is installed at the center of gravity within the body 16 and has a chamber 32 designed to include a shaft 19, a cam 18 and a part of the pump section 13.

  The guard 17 includes a pair of linear portions 33 that communicate with the chamber 32. Each of the linear portions 33 has a return spring that defines a position for operation of each pump portion 13 and acts on the pump portion 13.

  Each linear portion 33 is fluidly connected to each of the intake valve 14 and the discharge valve 15 of each pump portion 13 via the intake pipe 34 and the discharge pipe 36. Each of the intake pipe 34 and the discharge pipe 36 is formed in the main body 16.

  The body 16 has an inlet 20 that allows fuel to be delivered via the lubrication / cooling pipe 10 to cool / lubricate the guard 17.

  In particular, the lubrication / cooling pipe 10 is partially provided in the body 16 and terminates in a guard 17.

  The main body 16 has one or more inlets 21 (in this case, two), the fuel can be delivered via the supply pipes 8 by the inlets 21 and can be supplied to the pump units 13. . This fuel comes directly from an external source, which in certain cases is defined by the tank 2.

  More specifically, each suction valve 14 connects each supply pipe 8 and each pump unit 13 and is installed in the main body 16 in the vicinity of each inlet 21.

  Further, the main body 16 has an outlet 22, and a circulation pipe 24 connecting the guard 17 and the tank 2 passes through the outlet 22, and further returns the fuel used to cool and lubricate the guard 17 to the tank 2. Designed to be

  Finally, the body 16 has one or more outlets 27 (in this case having two) that allow the fuel compressed by each pump section 13 to flow outwardly via each delivery pipe 25.

  More specifically, each discharge valve 15 is fluidly installed between each pump section 13 and each delivery pipe 25 and is provided in the body 16 of the high-pressure pump 7 in the vicinity of each outlet 27. ing.

  The delivery pipe 25 merges at the T-shaped coupling portion 29. A single engine supply pipe 28 starts from the T-shaped joint 29.

  In use, the fuel present in the tank 2 is sucked up, compressed in advance by the suction pump 4, and sent to the high-pressure pump 7 via the circuit 6.

  In particular, the fuel discharged from the suction pump 4 fills the pipe 9 and then partly passes through the T-junction 11 and partly the lubrication / cooling pipe 10 and the rest part according to the rate defined by the flow control device 23. Flows into the connecting pipe 30.

  The fuel flowing in the lubrication / cooling pipe 10 arrives at the main body 16 of the high-pressure pump 7 through the inlet 20 and then fills the guard 17 to lubricate and cool the pump unit 13, the cam 18 and the shaft 19.

  The fuel that cools and lubricates the guard 17 fills the circulation pipe 24 and is discharged from the main body 16 via the outlet 22 and sent back to the tank 2.

  The fuel flowing through the connection pipe 30 fills the supply pipes 8 via the T-shaped joints 12 and reaches the main body 16 via the inlets 21.

  The fuel that has entered the main body 16 through each inlet 21 passes through each suction valve 14, is supplied to each pump unit 13, and is compressed to a predetermined pressure by each pump unit 13.

  The compressed fuel is discharged from each pump unit 13 through each discharge valve 15 and discharged from the main body 16 through each outlet 27 to fill each delivery pipe 25.

  The fuel that has passed through each delivery pipe 25 is collected in an internal combustion engine supply pipe 28 via a T-shaped joint 29.

  By experimenting with the characteristics of the high-pressure pump 7 and the compression device 5 made according to the present invention, the advantages they make possible are clear.

  Specifically, the fuel entering the high-pressure pump 7 passes through the suction valve 14 of each pump unit 13 and does not pass through the guard 17.

  In addition, the fuel is at the same temperature level as it is in the tank 2 and no rotational motion appears. In other words, the fuel is supplied to the suction valve 14 relatively “low temperature” and is not heated by having previously passed through the high-pressure pump 7.

  Therefore, the efficiency of this pump is optimized within a range that does not suffer from a decrease in efficiency due to the high temperature of the fuel at the outlet of the intake valve 14 and the presence of fuel rotation.

  Furthermore, the fuel compressed in the pump part 13 is not contaminated by possible mechanical shavings or impurities present in the guard 17.

  For this reason, the operation of the high-pressure pump 7 is free from the disadvantages caused by the presence of impurities in the fuel, and therefore does not require frequent maintenance and is not expensive.

  Finally, the high-pressure pump 7 and the compression device 5 described and exemplified in this specification may be modified and changed without departing from the scope of protection defined by the following claims.

  In particular, the circuit 6 may be formed from a member that does not have heat insulation properties, and may be connected to the high-pressure pump 7 via heat insulation connection means.

  Further, the circuit 6 is formed by a member that does not have heat insulation, and the member is connected to one or more intermediate devices installed sufficiently away from the high-pressure pump 7. The fuel may be heated before it is taken up.

An injection system for an internal combustion engine having a high pressure pump and a compression device is partially shown.

Claims (6)

A pump (7) for supplying compressed fuel to an internal combustion engine,
A body (16);
A compartment (17) provided in the body (16);
At least one pump part (13) provided in a movable manner in the compartment (17) for increasing the pressure of the fuel;
Fuel supply means (21, 14) for delivering fuel to the pump section (13);
Provided in the body (16), directly supplied with fuel from an external supply source (2), and further supplies the fuel to the compartment (17) for lubrication and / or cooling of the pump (7). A pump (7) having an inlet (20) fluidly connected to the compartment (17) at
The fuel supply means (21, 14) includes at least one other inlet (21), and the other inlet (21) is provided in the main body (16), and further from the external supply source (2). A pump characterized in that it is fluidly connected to the pump part (13) to supply directly received fuel to the pump part (13).   The fuel supply means (21, 14) includes a suction valve (14), and the suction valve (14) fluidly connects the other inlet (21) and the pump part (13), 2. The pump according to claim 1, wherein the pump is installed in the vicinity of another inlet (21).   The pump according to claim 2, characterized in that the suction valve (14) is installed at a position corresponding to the further inlet (21). A compression device for supplying pressurized fuel to an internal combustion engine,
The device (5)
A pump (7) for increasing the pressure of the fuel;
The pump (7) comprises distribution means (6) for allowing the use of compressed fuel;
The pump (7)
A body (16);
A compartment (17) provided in the body (16);
At least one pump part (13) provided in a movable manner in the compartment (17) for increasing the pressure of the fuel;
Fuel supply means (21) for delivering fuel to the pump section (13);
Provided in said body (16) and further fluidly connected to said compartment (17) for supplying said fuel to said compartment (17) for lubrication and / or cooling of said pump (7) A first entrance (20);
In a compression device (5) comprising distribution means (6) having a first fluid line (10) for feeding to a first inlet (20) of the pump (7),
The compression device (5)
The fluid supply means (21, 14) includes at least one second inlet (21), and the second inlet (21) is provided in the body (16) of the pump (7), and further includes the pump Fluidly connected to the section (13),
The distribution means (6) comprises at least one second fluid line (8) separated from the first fluid line (10), the second fluid line (8) being the second of the pump (7). A compression device, characterized in that it is supplied to the inlet (21) and installed outside the body (16) of the pump (7).   5. A compressor according to claim 4, characterized in that it comprises means along the second fluid line (8) for low heat conduction in cooperation with the fuel. 6. The compression apparatus according to claim 5, wherein the means with low heat conduction is defined by a member constituting the second fluid line (8).

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