阅读说明：本技术 燃料高压泵 (High-pressure fuel pump ) 是由 M·舍特尔 于 2021-06-04 设计创作，主要内容包括：本发明涉及一种用于内燃机的燃料高压泵(22),该燃料高压泵包括泵壳体(52)和阀装置(24),其中,阀装置(24)包括阀元件(60)以及阀座(68),其中,泵壳体(52)具有罐状构造的导向区域(59),在该导向区域中布置有贴靠在泵壳体(52)上的弹簧(62),该弹簧将阀元件(60)压紧到关闭位态中。(The invention relates to a high-pressure fuel pump (22) for an internal combustion engine, comprising a pump housing (52) and a valve device (24), wherein the valve device (24) comprises a valve element (60) and a valve seat (68), wherein the pump housing (52) has a pot-shaped guide region (59), in which a spring (62) is arranged, which bears against the pump housing (52) and presses the valve element (60) into a closed position.)

1. A high-pressure fuel pump (22) for an internal combustion engine, comprising a pump housing (52) having a delivery chamber (26), wherein the high-pressure fuel pump (22) further comprises an inlet region (20) having a connection for connection to a low-pressure region (28) of a fuel system (10), and wherein the high-pressure fuel pump (22) further has a valve device (24) which, in an open state, fluidically connects the inlet region (20) to the delivery chamber (26) and, in a closed state, separates the inlet region and the delivery chamber from one another, wherein the valve device (24) comprises a valve element (60) and a valve seat (68), wherein the valve element (60) is pressed in an axial direction (A) into a closed state in which it sealingly bears against the valve seat (68), wherein the valve seat (68) is fixed relative to the pump housing (52), in particular by a press (70) and/or a press, characterized in that the pump housing (52) has a pot-shaped guide region (59) for the valve element (60), in which guide region a spring (62) is arranged which bears against the valve housing (52) and presses the valve element (60) into the closed position.

2. The high-pressure fuel pump (22) according to claim 1, characterized in that the valve element (60) is guided in the guide region (59) of the pot-shaped design so as to be movable in the axial direction by means of a radial wall region (63), in particular wherein the axial extent of the radial wall region (63) from the base (64) of the guide region (59) of the pot-shaped design up to an edge (65) of the radial wall region (63) is smaller, equal or greater than the axial thickness (66) of the valve element (60) at its radially outer edge.

3. Fuel high-pressure pump (22) according to one of the preceding claims, characterized in that the valve element (60) has a dome-shaped projection (71) on the side facing the bottom (64) of the tank-shaped guide region (59) and in that a complementarily configured recess (72) for accommodating the projection (71) is arranged in the bottom (64) of the tank-shaped guide region (59), in particular wherein the dome-shaped projection (71) constitutes a centering of a spring (62) pressing the valve element (60).

4. The high-pressure fuel pump (22) according to one of the preceding claims, characterized in that the pot-shaped guide region (59) is formed by an end section of a stepped blind hole in the pump housing (52).

5. The high-pressure fuel pump (22) according to one of the preceding claims, characterized in that the pump housing (52) has a connecting opening (73) arranged radially to the side of the valve element (60), which connecting opening constitutes a part of the fluid connection of the inlet region (20) and the delivery chamber (26) when the valve element (60) is open.

6. The high-pressure fuel pump (22) according to the preceding claim, characterized in that the connection opening (73) is configured as an elongated hole (74) extending in the circumferential direction.

7. The high-pressure fuel pump (22) according to the preceding claim, characterized in that the elongate hole (74) extends over a quarter, in particular over a half, of the circumference of the valve element (60).

8. The high-pressure fuel pump (22) as claimed in one of the preceding claims, characterized in that the pump housing (52) has a connecting channel (75) of the pressure-limiting valve (50) arranged radially on the side of the valve element (60), which, when the valve element (60) is open, constitutes part of a fluid connection between the inlet region (20) and the pressure-limiting valve (50) of the high-pressure region fed through the delivery chamber (26).

9. The high-pressure fuel pump (22) according to the preceding claim, characterized in that the pressure-limiting valve (50) is arranged in a bore (51) which is oriented in particular orthogonally to a piston longitudinal axis (38) of a piston (34) arranged in the delivery chamber (26), which bore has been introduced into the pump housing (52) from a high-pressure side of the pressure-limiting valve (50), and in that a connection channel (75) which opens into the pressure-limiting valve (50) is formed by a section (67) of the bore which extends parallel to the bore (51) in which the pressure-limiting valve (50) is arranged.

Technical Field

The invention relates to a high-pressure fuel pump for an internal combustion engine.

Background

A high-pressure fuel pump is used in a fuel system of an internal combustion engine in order to compress fuel from a pre-pressure prevailing in a low-pressure region to an injection pressure required for fuel injection. Such high-pressure fuel pumps usually have at least one piston which can be moved axially by means of a drive, which is formed, for example, by a cam or an eccentric. By means of the axial movement of the piston, fuel is sucked in a suction stroke from a low-pressure region into the delivery chamber through a quantity control valve which forms the valve arrangement and is partially referred to as the inlet valve. During the delivery stroke, the fuel is compressed in the piston chamber and is supplied via an outlet valve to a high-pressure region, which is usually designed as a rail. If the quantity control valve is not closed at the beginning of the delivery stroke or is open during the delivery stroke, the quantity of fuel supplied to the high-pressure region via the outlet valve can thereby be controlled.

Such high-pressure fuel pumps usually comprise an electromagnetic actuating device for influencing the position of a valve element of the quantity control valve. Typically, the valve element can be forcibly opened or held open, for example by a tappet, by means of an electromagnetic actuating device. A typical inlet valve or volume control valve comprises a valve spool, the already mentioned valve element and a valve seat. The valve element is typically pressed into the closed position by a spring bearing against the valve slide and the valve element. In the closed position, the valve element rests against the valve seat and separates the delivery chamber side from the intake side. The valve element and the valve seat are typically arranged such that they contact a housing of the high-pressure fuel pump and are fixed in the housing by means of the pressed portion and the pressing portion. Modern engine configurations and operating modes require increasingly higher pressures. This increases the requirements for anchoring (Verankerung) of the inlet valve.

Disclosure of Invention

The object of the present invention is to provide a high-pressure fuel pump which is simple to produce, meets the requirements for a high delivery pressure and operates or is constructed in a robust and reliable manner.

This object is achieved by a high-pressure fuel pump according to the invention. Further advantageous embodiments result from the following description and from the following description.

The invention relates to a high-pressure fuel pump for an internal combustion engine. The high-pressure fuel pump has a pump housing. A delivery chamber is arranged in the pump housing. Typically, the cylinder delimiting the delivery chamber is realized by a hole in the pump housing, but the use of a cylinder sleeve is also conceivable. The high-pressure fuel pump further comprises an inlet region having a connection for connection to a low-pressure region of a fuel system in which the high-pressure fuel pump is used. Typically, the connection is designed as a separate connection piece which is attached to the housing, which can provide advantages in terms of production technology. The connecting piece can be designed, for example, as a deep-drawn part. However, it is also conceivable for the connection to consist of the material of the pump housing. The high-pressure fuel pump further comprises a valve arrangement which, in an open state, fluidly connects the inlet region with the delivery chamber and, in a closed state, separates them from one another. The valve device is also referred to as an inlet valve or a quantity control valve. The valve device comprises a valve element and a valve seat. The valve element is pressed in the axial direction into the closed position just mentioned. For this purpose, the valve element is usually pressed into the valve device by means of a spring which bears in particular against the valve element. In the closed position, the valve element rests sealingly against the valve seat. The valve seat is fixed relative to the pump housing, in particular by a hold-down. However, the valve seat can also be fixed relative to the pump housing by a screw connection, wherein a snap edge is provided which "digs" into the material of the pump housing or is deformed and thus forms a sealing surface. According to the invention, it is now provided that the pump housing has a guide region of pot-shaped design for the valve element, in which guide region a spring is arranged which bears against the pump housing and presses the valve element into the closed position.

Preferably, the valve element is guided in a guide region of the pot-like design movably in the axial direction by a radial wall region. The radial wall region is configured in particular in an annular manner around the valve element. Here, interruptions in the wall region are possible. In particular, the axial extent of the radial wall region from the base of the guide region of the pot-like design to the edge of the radial wall region is smaller than the axial thickness of the valve element on its radially outer edge. The edge is the edge of the radial wall region facing the valve seat in the axial direction. The valve element is in particular of plate-like design, wherein the axial thickness of the valve element corresponds to the thickness of the plate-like valve element on its radially outer edge. In particular, the edge of the radial wall region is arranged relative to the valve seat in such a way that the distance of the edge of the radial wall region facing the valve seat in the axial direction is smaller than the axial thickness of the valve element on its radially outer edge. The configuration just described facilitates the guidance of the valve element in the guide region of the pot-shaped configuration.

Preferably, the valve element has a dome-shaped projection on the side facing the bottom of the guide region of the pot-shaped construction. A complementarily configured recess for receiving the projection can be arranged in the base of the guide region of the pot-shaped configuration, in particular, wherein the dome-shaped projection forms a centering of a spring pressing the valve element. In other words, the bottom or the groove of the guide region of the pot-shaped design serves as a travel stop for the valve element or for the dome-shaped projection of the valve element.

Preferably, the guide region of the pot-shaped design is formed by an end section of a stepped blind hole in the pump housing. This simplifies the production of the high-pressure pump, which can be produced at low cost.

Preferably, the pump housing has a connection opening arranged radially beside the valve element, which connection opening forms part of the fluid connection of the inlet region and the delivery chamber when the valve element is open. Preferably, the connection opening is configured as an elongated hole extending in the circumferential direction. In particular, the elongate hole extends over more than a quarter, in particular more than a half, of the circumference of the valve element. In other words, the elongate hole may extend in the form of a circular arc, wherein the circular arc preferably opens out at an angle of more than 90 ° and further preferably at an angle of more than 180 °. Such a fluid connection can be produced simply and ensures reliable functioning.

Preferably, the pump housing has a connecting channel of the pressure-limiting valve arranged radially on the side of the valve element, which connecting channel, when the valve element is open, forms part of the fluid connection between the inlet region and the pressure-limiting valve of the high-pressure region fed by the delivery chamber. Such a fluid connection to the pressure-limiting valve can be produced simply and ensures reliable functioning.

The connecting channel and the connecting opening can be designed to extend in the axial direction and in particular parallel to one another, which provides advantages in terms of production technology, in particular the possibility of producing two connections in one operation.

Preferably, the pressure-limiting valve is arranged in a bore which is oriented in particular orthogonally to the longitudinal piston axis of the piston arranged in the delivery chamber, said bore having been introduced into the pump housing from the high-pressure side of the pressure-limiting valve, and the connection channel to the pressure-limiting valve is formed in particular by a section of the bore which extends parallel to the bore in which the pressure-limiting valve is arranged.

It is likewise conceivable to provide a plurality of connecting channels and/or connecting openings. The flow cross section can be increased with low manufacturing expenditure.

The high-pressure fuel pump according to the invention is used in particular for delivering gasoline and in particular in the fuel system of a gasoline engine.

Drawings

Further features, application possibilities and advantages of the invention emerge from the following description of an exemplary embodiment of the invention, which is illustrated on the basis of the drawings, wherein these features are not only relevant individually but also in various combinations for the invention, but are not explicitly indicated.

The figures show:

FIG. 1 is a simplified schematic illustration of a fuel system for an internal combustion engine;

FIG. 2 is a cross-sectional view of the high pressure fuel pump;

FIG. 3 is a fragmentary section of FIG. 2;

FIG. 4 a first embodiment of the connection of the inlet region with the piston chamber; and

fig. 5 a second embodiment of the connection of the inlet area to the piston chamber.

Detailed Description

Fig. 1 shows a fuel system 10 for an internal combustion engine, not shown in detail, in a simplified schematic representation. Fuel is supplied from the fuel tank 12 via the suction line 14 via the prefeed pump 16 and the low-pressure line 18 via an inlet region 20 to a high-pressure fuel pump 22. In connection with the inlet region 20, a valve device 24 is arranged, which forms a quantity control valve 25 of the high-pressure fuel pump 22 and by means of which the piston chamber 26 can be connected to a low-pressure region 28, which comprises the prefeed pump 16, the suction line 14 and the fuel tank 12.

The electromagnetic actuating device 32 can be actuated by the control unit 30. The quantity control valve 25 can in turn be actuated or its position influenced by means of a solenoid actuator 32, which will also be discussed in detail later. The high-pressure fuel pump 22 is currently embodied as a piston pump, wherein the pistons 34 can be moved up and down along a piston longitudinal axis 38 by means of a drive 36 embodied as a cam disk, which is schematically illustrated by an arrow with the reference number 40.

An outlet valve 44, which is embodied in fig. 1 as a spring-loaded check valve and which can be opened toward the outlet 42, is arranged hydraulically between the delivery chamber 26 and the outlet 42 of the high-pressure fuel pump 22. The outlet 42 is connected to a high-pressure line 46 and, via the latter, to a high-pressure accumulator 48 ("rail"). Furthermore, a pressure-limiting valve 50, which is likewise designed as a spring-loaded check valve and can be opened toward the delivery chamber 26, is arranged hydraulically between the outlet 42 and the delivery chamber 26. In operation of fuel system 10, pre-feed pump 16 delivers fuel from fuel tank 12 into low-pressure line 18. The inlet valve 24 can be closed and opened according to the respective demand for fuel. Thereby influencing the amount of fuel delivered to the high-pressure accumulator 48. The solenoid actuator 32 is controlled accordingly by the control unit 30 as already described and influences the position of the quantity control valve 25.

The high-pressure fuel pump 22 is partially shown in cross-section in fig. 2. As can be seen from the illustration in fig. 2, the pressure-limiting valve 50, the outlet valve 44 and the inlet valve 24 are arranged in a pump housing 52. The delivery chamber 26, also referred to as piston chamber 26, and part of the piston 34 are also arranged in the pump housing 52. The lower end of the piston projecting from the pump housing 52 is connected to a piston disc 54. The piston 34 rests via a piston disk 54 against a drive 36, not shown in fig. 2. The configuration and arrangement of the outlet valve 44, the pressure-limiting valve 50 and the manner of construction of the region surrounding them are to be understood as examples and can also be configured differently. The same applies to the piston 34 or the seal arranged at the lower part of the piston and other configurations in this region.

A damper device, which is not shown in fig. 2 for reasons of clarity, is arranged at the end of the high-pressure fuel pump 22 opposite the piston disc 54. The damper device serves to compensate for pressure fluctuations occurring during operation of the high-pressure fuel pump 22.

The valve device 24 and the solenoid operated device 32 will be described in detail below. The solenoid operator 32 includes a solenoid 56. If the electromagnetic coil 56 is energized, a magnetic field is formed, by means of which the position of the valve needle 58 can be adjusted. The valve element 60 of the quantity control valve 25 can be forcibly opened or held open by the valve needle 58. The position of the quantity control valve 25 can thus be influenced by means of the valve needle 58 via the solenoid 56, the latter being opened or held open.

The area surrounding the valve device 24 is shown in detail in fig. 3. The valve device 24 includes a valve element 60 and a valve seat 68. The valve element 60 is biased into the closed position by a spring 62. In this closed position, the valve element rests sealingly against the valve seat 68. The valve seat 68 is now fixed relative to the pump housing 52 by the press 70 and the pressing.

The valve element 60 is disposed in the flow passage 61. The flow channel 61 connects the low pressure region 28 with the delivery chamber 26. Depending on the position of the valve element 60, the flow channel 61 is fluidly continuous or fluidly interrupted. In other words, depending on the position of valve element 60, low pressure region 28 and transfer chamber 26 are in fluid communication with each other or are fluidly isolated from each other.

The axis of movement of the valve element 60 is identified by reference numeral 80. The axis of motion 80 corresponds to an axial direction a orthogonal to the radial direction R.

The pump housing 52 also has a guide region 59 for the pot-shaped configuration of the valve element 60. A spring 62 is arranged in the guide region 59 of the pot-shaped design, which spring bears against the pump housing 52. Spring 62 biases valve element 60 into the closed position. In other words, the valve element 60 is biased against the valve seat 68 by the spring 62. Thus, no additional elements need to be provided, for example, in order to fix the spring thereto.

The valve element 60 is movably arranged in the guide region 59 of the pot-shaped design in the axial direction a, i.e. along the movement axis 80. The valve element 60 is guided by a radial wall region 63. The radial wall region 63 extends annularly around the valve element 60. In other words, the wall region 63 serves as a linear guide for the valve element 60 along the movement axis 80. Here, it is conceivable for the wall region 63 to have a discontinuity.

The radial wall region 63 extends in the axial direction a from a base 64 of the pot-shaped guide region 59 to an edge 65 of the radial wall region 63. The axial extent of the wall region 63 is greater than the axial thickness 66 of the valve element 60 on its radially outer edge. However, the extent of wall region 63 may also be less than the axial thickness 66 of valve element 60 at its radially outer edge. The valve element 60 is currently embodied in the form of a plate, wherein the axial thickness 66 corresponds to the thickness of the plate on the radially outer edge.

The valve element 60 has a dome-shaped projection 71 on the side facing the bottom 64 of the guide region 59 of the pot-like configuration. A recess 72, which is configured complementary to the projection 71 and is intended to receive the projection 71, is arranged in the base 64 of the guide region 59, which is configured in a pot-like manner. The spring 62 bears against the valve element 60, wherein the spring is arranged around the dome-shaped projection 71. Here, the dome-shaped projection 71 constitutes a centering portion of the spring 62 for pressing the valve element 60.

The pump housing 52 has a connection opening 73 arranged radially beside the valve element 60. Which constitutes a part of the fluid connection of the inlet region 20 with the delivery chamber 26 when the valve element 60 is open.

Furthermore, the pump housing 52 has a connecting channel 75 arranged radially to the side of the valve element 60. The connecting channel 75 is part of the fluid connection between the inlet region 20 and the pressure limiting valve 50 when the valve element 60 is open.

A pressure limiting valve 50 is arranged in the bore 51. The bore 51 is oriented orthogonally to the piston longitudinal axis 38 of the piston 34 arranged in the delivery chamber 26. A bore 51 is introduced into the pump housing 52 from the high-pressure side of the pressure-limiting valve 50. The connecting channel 75 is arranged in parallel with the pressure-limiting valve 50. The connecting channel 75 extends along the section 67 formed by a hole.

In the present case, the connection channel 75 and the connection opening 73 are embodied as through openings which extend parallel to the movement axis 80 and thus parallel to one another. These through openings can be produced by means of simple holes. The connection channel 75 and the connection opening 73 are sealingly closed in the axial direction a (in fig. 3, at the right end of the through-opening) relative to the inlet region 20 by the valve seat 68.

The connection channel 75 and the connection opening 73 are fluidly connected to each other. For this purpose, a shoulder 81 is provided in the guide region of the pot-shaped design. This shoulder adjoins an edge 65 of the radial wall region 63 and extends along the circumference of the pot-shaped guide region 59. In other words, the shoulder 81 extends radially over the pot-shaped guide region 59 and is arranged radially next to the valve element 60.

If the radial wall region 63 has at least one interruption, the shoulder 81 extends in the axial direction to the base 64 of the pot-shaped guide region 59 in this region.

It is likewise conceivable for the fluid connection between the connection opening 73 and the connection channel 75 to be realized by a bore, which extends, for example, along or parallel to the piston longitudinal axis 38 and connects the piston chamber 26 to the bore 51 of the pressure-limiting valve 50.

The fluid connection of the inlet and outlet region 20 to the piston chamber 26 is shown in two different embodiments in fig. 4 and 5. These two figures each show a guide region 59 of pot-like design in the pump housing 52 in a perspective view. The pot-shaped guide region 59 is already formed by an end section of the stepped blind hole in the pump housing 52. Such a guide region 59 of pot-like design can be produced simply and inexpensively by means of a stepped bore.

As can be seen clearly in fig. 4 and 5, the valve seat 68 in the guide region 59 of the pot-like design rests against a continuous bearing surface which is interrupted only by the connecting opening 73 and the connecting channel 75. Thereby possible deformation can be prevented or at least reduced.

The two exemplary embodiments of fig. 4 and 5 differ in that the connection opening 73 shown in fig. 4 is configured as an elongated hole 74 in fig. 5. The slot 74 now extends radially along the guide region 59 of the pot-shaped design. This enables a larger flow rate when the valve element 60 is open. The larger or longer the slot 74 is made, the greater the flow rate. Currently, the elongated aperture 74 extends less than half of the circumference of the valve element 60. It is also conceivable to increase the flow rate by providing a plurality of connection openings 73.